LogoCrystal's MCW Coder Hub

H40.1111

50 min read

Short Definition

Primary open-angle glaucoma, right eye, mild stage

Long Definition

ICD-10-CM code H40.1111 identifies primary open-angle glaucoma (POAG) affecting the right eye specifically at the mild stage of disease severity. Primary open-angle glaucoma is a chronic, progressive optic neuropathy characterized by characteristic patterns of optic nerve head damage (optic disc cupping with neuroretinal rim loss), retinal nerve fiber layer (RNFL) defects, and corresponding visual field loss, typically occurring in the setting of elevated intraocular pressure (IOP), though IOP may be in the statistically normal range in some cases. POAG is the most common form of glaucoma worldwide and a leading cause of irreversible blindness, affecting approximately 3-4% of people over age 40 in the United States, with prevalence increasing with age, and disproportionately affecting individuals of African, Hispanic, and Asian descent. The term “open-angle” refers to the appearance of the anterior chamber angle on gonioscopic examination, where the angle structures (trabecular meshwork, scleral spur, ciliary body band) are visible and not obstructed by peripheral iris tissue, distinguishing it from angle-closure glaucoma.

The “primary” designation indicates that the glaucoma is not secondary to another identifiable ocular or systemic condition, such as trauma, inflammation, steroid use, or other causes. The pathophysiology involves dysfunction of the trabecular meshwork drainage system, leading to increased resistance to aqueous humor outflow, which typically (though not always) results in elevated IOP. Chronic elevation of IOP causes mechanical stress and vascular insufficiency at the optic nerve head, particularly at the lamina cribrosa where the retinal ganglion cell axons exit the eye, leading to progressive axonal damage and retinal ganglion cell death. This process is irreversible—once retinal ganglion cells die and optic nerve fibers are lost, visual function cannot be restored.

The “mild stage” designation under the ICD-10-CM staging system indicates early glaucomatous damage with visual field defects present but not involving both hemifields and not involving the central 5 degrees of fixation. According to ICD-10-CM staging criteria, mild glaucoma is defined as having optic nerve abnormalities consistent with glaucoma (increased cup-to-disc ratio, rim thinning, RNFL defects, disc hemorrhages) with corresponding visual field abnormalities present, but neither hemifield (superior or inferior) showing complete involvement, and the central 5 degrees of fixation remaining intact. This staging system differs from other classification systems (such as Hodapp-Parrish-Anderson, Mills, or visual field index-based systems) but provides a standardized framework for ICD-10 coding. Patients with mild stage POAG typically have mean deviation (MD) on automated perimetry better than -6 dB, early arcuate scotomas or nasal steps, and relatively preserved central vision, though these parameters are approximations as ICD-10 staging is based on regional field involvement rather than global indices.

Risk factors for POAG include elevated IOP (most important modifiable risk factor), advanced age, African ancestry, family history of glaucoma, myopia (nearsightedness), thin central corneal thickness, diabetes, hypertension, and possibly cardiovascular disease. Diagnosis requires comprehensive ophthalmologic examination including IOP measurement, gonioscopy to confirm open angles, optic nerve evaluation with documentation of cup-to-disc ratio and neuroretinal rim assessment, RNFL assessment (clinical examination and/or optical coherence tomography), and automated visual field testing (perimetry) demonstrating glaucomatous field defects. Management of mild stage POAG focuses on lowering IOP to slow or halt disease progression, as IOP reduction is currently the only proven treatment strategy. Target IOP is individualized based on baseline IOP, severity of damage, rate of progression, and life expectancy, but generally for mild glaucoma, a 20-30% reduction from baseline IOP or target of less than 18 mmHg is recommended.

Treatment modalities include topical IOP-lowering medications (prostaglandin analogs as first-line, beta-blockers, alpha-2 agonists, carbonic anhydrase inhibitors, rho kinase inhibitors), laser trabeculoplasty (selective laser trabeculoplasty or argon laser trabeculoplasty) which enhances trabecular outflow, and incisional surgery (trabeculectomy, tube shunt implantation, or minimally invasive glaucoma surgery) if medical and laser therapies are insufficient, though surgery is typically reserved for more advanced disease or medication intolerance.

Prognosis for mild stage glaucoma is generally good with appropriate treatment and monitoring, with the goal of preventing progression to moderate or severe stages and preserving functional vision for the patient’s lifetime. Regular monitoring with visual fields, OCT, and optic nerve evaluation every 3-6 months initially and then annually if stable is essential to detect progression early. Patient education regarding the chronic nature of the disease, importance of medication adherence, and need for lifelong monitoring is critical.

This code specifically indicates the right eye is affected at mild stage; if the left eye is involved or if bilateral disease is present, different codes must be used, and separate codes are required for each eye when bilateral asymmetric disease is present.

Area of Body

Right eye - aqueous humor drainage system and optic nerve:

Primary Pathology Site - Right Eye:

Trabecular Meshwork (Site of Outflow Dysfunction):

  • Location: Angle of anterior chamber, 360 degrees around the eye at the junction of cornea and iris
  • Normal function: Primary drainage pathway for aqueous humor (conventional outflow)
    • Aqueous filters through trabecular meshwork → Schlemm’s canal → collector channels → episcleral veins
    • Accounts for ~80-90% of aqueous outflow
  • Pathology in POAG:
    • Increased resistance to outflow at level of trabecular meshwork
    • Trabecular meshwork dysfunction is hallmark of POAG
  • Histopathologic changes in POAG:
    • Decreased trabecular meshwork cellularity (loss of TM cells beyond normal aging)
    • Extracellular matrix accumulation in juxtacanalicular tissue (adjacent to Schlemm’s canal)
    • Thickening of trabecular beams
    • Fusion of trabecular beams (from cell loss and denuded areas)
    • Reduced giant vacuole formation in Schlemm’s canal endothelium (reduced pore density)
    • Increased TM stiffness (impairs outflow)
    • Accumulation of debris, pigment, glycosaminoglycans
    • Loss of phagocytic activity of TM cells
    • Result: Increased resistance to aqueous outflow → elevated IOP

Schlemm’s Canal:

  • Circular channel running parallel to limbus
  • Collects aqueous from trabecular meshwork
  • Changes in POAG:
    • Reduced pore size and density in inner wall
    • Loss of giant vacuoles (transendothelial channels)
    • Continuous thickened basement membrane

Anterior Chamber Angle:

  • Must be OPEN in POAG (distinguishes from angle-closure)
  • Angle structures visible on gonioscopy:
    • Schwalbe’s line
    • Trabecular meshwork (pigmented in POAG often)
    • Scleral spur
    • Ciliary body band
  • Open angle: Grade 3-4 on Shaffer classification

Intraocular Pressure (IOP):

  • Normal IOP: 10-21 mmHg (statistical range, mean ~15-16 mmHg)
  • In POAG: Often elevated (>21 mmHg), but not always
    • ~30-40% of POAG patients have IOP <21 mmHg at initial presentation (normal-tension glaucoma)
    • IOP may be elevated only intermittently or at different times of day (diurnal variation)
  • Mechanism: Imbalance between aqueous production and outflow
    • Production normal (2-3 μL/min by ciliary body)
    • Outflow impaired (resistance increased at trabecular meshwork)
  • IOP as risk factor:
    • Higher baseline IOP = higher glaucoma risk
    • Each 1 mmHg IOP elevation increases glaucoma risk by ~10%
    • IOP lowering is ONLY proven treatment for POAG

Site of Damage - Optic Nerve Head (Right Eye):

Optic Nerve Head (Optic Disc):

  • Location: 3-4 mm nasal to fovea, 1.5 mm in diameter
  • Structure:
    • Neuroretinal rim: Contains ~1.2 million retinal ganglion cell axons
    • Optic cup: Central depression (normally <50% of disc diameter)
    • Lamina cribrosa: Sieve-like structure through which axons pass; site of vulnerability in glaucoma
  • Glaucomatous Optic Neuropathy Changes:
    • Progressive cupping: Enlargement of optic cup due to loss of axons
    • Cup-to-disc ratio (C/D) increases:
      • Normal C/D: 0.1-0.4 (average ~0.3)
      • Mild glaucoma: C/D typically 0.5-0.7 (variable)
      • Vertical C/D often larger than horizontal
      • Asymmetry between eyes >0.2 suspicious
    • Neuroretinal rim thinning:
      • Rim loss typically follows ISNT rule breakdown (Inferior thinnest first, then Superior, then Nasal, then Temporal)
      • Inferior and superior rim loss most common in early POAG
    • Focal notching: Local loss of rim tissue
    • RNFL defects: Wedge-shaped defects visible on fundoscopy or OCT
    • Disc hemorrhages (Drance hemorrhages):
      • Splinter hemorrhages at disc margin (especially inferotemporal or superotemporal)
      • Sign of active glaucomatous damage
      • Present in ~10-20% of glaucoma patients at any given time
    • Lamina cribrosa abnormalities:
      • Posterior bowing, compression, disruption
      • Site of mechanical axonal damage
    • Peripapillary atrophy:
      • Alpha zone (peripheral): Hypertrophy/hypotrophy of RPE
      • Beta zone (adjacent to disc): Loss of RPE and choroid; associated with glaucoma
    • Bayoneting of vessels: Sharp angulation at cup margin

Retinal Nerve Fiber Layer (RNFL):

  • Layer of retina containing ganglion cell axons
  • Travels from ganglion cells → optic nerve head in arcuate pattern
  • Superior and inferior arcuate bundles most vulnerable in glaucoma
  • RNFL thinning in POAG:
    • Visible on fundoscopy (loss of striations)
    • Quantified by OCT (optical coherence tomography)
    • Mild POAG: Early focal or diffuse thinning, especially inferotemporal and superotemporal
    • Corresponds to visual field defects

Retinal Ganglion Cells:

  • ~1.2 million ganglion cells in healthy retina
  • Concentrated in macula (especially within central 8 degrees)
  • In POAG: Progressive ganglion cell death (apoptosis)
    • Irreversible - once cells die, cannot regenerate
    • May lose 25-35% of ganglion cells before visual field defects detectable
    • Loss continues with disease progression

Visual Field (Right Eye):

  • In mild POAG: Early glaucomatous visual field defects
  • ICD-10 Mild Stage Definition:
    • Visual field abnormalities present
    • Neither superior NOR inferior hemifield completely involved
    • Central 5 degrees of fixation NOT involved
  • Common early VF patterns:
    • Paracentral scotomas: Small defects near fixation (5-15 degrees)
    • Arcuate scotomas: Arc-shaped defects respecting horizontal midline
    • Nasal step: Defect in nasal field with step at horizontal midline
    • General depression: Diffuse sensitivity reduction
    • Localized defects in Bjerrum area (10-20 degrees from fixation)
  • Automated perimetry indices (approximate for mild):
    • Mean deviation (MD): Better than -6 dB (mild loss)
    • Pattern standard deviation (PSD): Elevated (localized loss)
    • Visual Field Index (VFI): >80-90% (variable)
    • Glaucoma Hemifield Test (GHT): Outside normal limits or borderline

Structures NOT Primarily Affected:

  • Anterior segment: Normal (cornea, lens, iris structurally normal)
  • Macula: Typically preserved in mild POAG (central vision good)
  • Peripheral retina: Structurally normal (no retinal tears, detachment)
  • Optic nerve function: Some axons damaged but many functional

Pathophysiology Summary:

  1. Trabecular meshwork dysfunction → Increased outflow resistance
  2. Elevated IOP (typically) → Mechanical stress at optic nerve head
  3. Lamina cribrosa compression/deformation → Axonal damage
  4. Vascular insufficiency → Ischemic component of damage
  5. Retinal ganglion cell apoptosis → Irreversible cell death
  6. RNFL thinning → Loss of axonal layer
  7. Optic nerve head cupping → Enlargement of cup as rim tissue lost
  8. Visual field defects → Functional vision loss corresponding to structural damage

Mild Stage Characteristics:

  • Early in disease process
  • Limited structural damage (moderate C/D increase, focal rim loss, early RNFL thinning)
  • Limited functional loss (early VF defects, hemifields not completely involved, central vision preserved)
  • Potentially reversible if “pre-perimetric” (structural changes before VF loss) - once VF loss, damage irreversible but progression can be slowed/halted with treatment

Clinical Presentation and Diagnosis

Patient Presentation:

Typical Presentation:

  • ASYMPTOMATIC (most common in mild stage)
    • Mild glaucoma causes NO symptoms
    • No pain (unlike acute angle-closure)
    • No vision loss perceived by patient (early peripheral VF loss not noticed)
    • No redness, no halos, no discomfort
    • Patient unaware of disease
  • Discovered on:
    • Routine comprehensive eye examination
    • Screening for glaucoma (family history, high-risk patient)
    • Incidental finding during examination for other reasons
    • Follow-up of ocular hypertension patient who has converted to glaucoma

Rare Symptomatic Presentation:

  • Patient may notice peripheral vision loss if very observant (rare in mild stage)
  • Usually asymptomatic until moderate-severe stage

Patient History:

Risk Factors (Essential to Document):

  • Age: Prevalence increases with age (>40 years significantly increased risk)
  • Race/Ethnicity:
    • African American: 4-5x higher risk, earlier onset, more severe
    • Hispanic/Latino: 2x higher risk
    • Asian: Higher risk of normal-tension glaucoma
    • Caucasian: Lower risk
  • Family history: First-degree relative with glaucoma increases risk 4-9x
  • Elevated IOP: Most important modifiable risk factor
  • Refractive error: Myopia (nearsightedness) associated with increased risk
  • Central corneal thickness: Thin cornea (<555 microns) increases risk 3x
  • Systemic conditions:
    • Diabetes mellitus
    • Hypertension (controversial - may increase or decrease risk)
    • Cardiovascular disease
    • Migraine
    • Sleep apnea
  • Medications: Long-term corticosteroid use (can cause secondary glaucoma, not POAG)
  • Eye trauma history
  • Previous eye surgery

Symptoms (Usually NONE in Mild Stage):

  • No symptoms typically
  • Vision usually good (20/20 or near)
  • No awareness of peripheral field loss

Physical/Ophthalmologic Examination:

Visual Acuity:

  • Typically normal in mild POAG (20/20 to 20/30)
  • Central vision preserved in mild stage
  • Reduction in VA indicates advanced disease or other pathology

Intraocular Pressure (IOP):

  • Measure with Goldmann applanation tonometry (gold standard)
  • May be elevated (>21 mmHg) or normal
    • ~60-70% of POAG patients have elevated IOP at presentation
    • ~30-40% have IOP ≤21 mmHg (normal-tension glaucoma subset)
  • In mild POAG with elevated IOP: Typically 22-28 mmHg (mild-moderate elevation)
  • Document:
    • IOP value each eye
    • Time of day (IOP has diurnal variation, often peaks morning)
    • Method of measurement
  • Multiple measurements important (single reading insufficient)

Anterior Segment Examination:

  • Slit lamp:
    • Cornea: Assess for edema, scars (prior surgery), dystrophy
    • Anterior chamber: Deep and quiet (no cells/flare)
    • Iris: Normal, no neovascularization, no posterior synechiae
    • Lens: Assess for cataract (age-related, not caused by glaucoma but coexists)

Gonioscopy - ESSENTIAL for POAG Diagnosis:

  • Must document OPEN anterior chamber angle
  • Technique: Goniolens (Goldmann, Zeiss, Sussman) with slit lamp
  • Angle structures visible:
    • Schwalbe’s line (peripheral)
    • Trabecular meshwork (may be pigmented)
    • Scleral spur
    • Ciliary body band
  • Grading:
    • Shaffer grade 3-4 (wide open): Typical in POAG
    • Spaeth system: Document angle width, iris configuration, insertion
  • Findings in POAG:
    • Open angle 360 degrees
    • Increased trabecular pigmentation often present (not diagnostic but common)
    • No peripheral anterior synechiae (PAS)
    • No angle recession (if traumatic history, different diagnosis)
    • No neovascularization
  • Purpose: Distinguish open-angle from angle-closure glaucoma

Dilated Fundus Examination - ESSENTIAL:

Optic Nerve Head Assessment (Most Important):

  • Must dilate for adequate examination
  • Direct ophthalmoscopy, slit lamp biomicroscopy (78D or 90D lens), or fundus photography
  • Document (ESSENTIAL for diagnosis and staging):
    • Cup-to-disc ratio (C/D):
      • Vertical C/D (more important - damage typically vertical)
      • Horizontal C/D
      • In mild POAG: C/D typically 0.5-0.7 (variable; large physiologic cups exist)
      • Asymmetry between eyes: >0.2 difference suspicious for glaucoma
    • Neuroretinal rim:
      • Color: Should be pink and healthy; pallor suggests damage
      • Thickness: Assess all quadrants
      • ISNT rule: Inferior rim thickest, then Superior, Nasal, Temporal (normal)
        • In mild POAG: ISNT rule breakdown - inferior or superior thinning
      • Focal notching: Localized rim loss (suspicious)
    • Retinal nerve fiber layer (RNFL):
      • Visible as striated pattern on red-free light
      • RNFL defects: Wedge-shaped dark areas (loss of fibers)
      • Common in inferotemporal and superotemporal regions in early POAG
    • Disc hemorrhages (Drance hemorrhages):
      • Splinter hemorrhages at disc margin
      • Sign of active glaucomatous progression
      • Document if present (location, size)
    • Peripapillary atrophy:
      • Beta zone (adjacent to disc): Loss of RPE, associated with glaucoma
      • Alpha zone (peripheral): Less specific
    • Disc size: Large discs have larger physiologic cups (may mimic glaucoma)

Retina and Macula:

  • Typically normal in POAG
  • Rule out other pathology (diabetic retinopathy, macular degeneration, retinal vascular occlusion)

Optical Coherence Tomography (OCT) - HIGHLY RECOMMENDED:

  • Non-invasive imaging of optic nerve and RNFL
  • RNFL thickness analysis:
    • Measures thickness of nerve fiber layer around optic nerve
    • Color-coded: Green = normal, Yellow = borderline, Red = abnormal
    • In mild POAG: Focal or diffuse thinning, often inferior or superior
    • Average RNFL thickness: <85-90 microns concerning; normal ~95-105 microns
  • Ganglion cell complex (GCC) analysis:
    • Measures macular ganglion cell layer
    • Earlier detection possible than RNFL
  • Optic nerve head (ONH) analysis:
    • Rim area, disc area, cup volume, C/D ratio quantified
  • Baseline OCT essential for monitoring progression over time

Visual Field Testing (Automated Perimetry) - ESSENTIAL:

  • Humphrey Visual Field (most common) or Octopus
  • Protocol: 24-2 or 30-2 SITA Standard or SITA Fast
    • 24-2: Tests central 24 degrees (most common for glaucoma)
    • 30-2: Tests central 30 degrees (includes more peripheral)
    • 10-2: Central 10 degrees (for advanced glaucoma)
  • Reliability indices:
    • Fixation losses <20%
    • False positives <15%
    • False negatives <33%
    • Unreliable test must be repeated
  • In MILD POAG (ICD-10 criteria):
    • Visual field abnormalities present (glaucomatous defects confirmed)
    • Neither superior NOR inferior hemifield completely involved
    • Central 5 degrees of fixation NOT involved
  • Common VF patterns in mild POAG:
    • Paracentral scotomas (small defects 5-15 degrees from fixation)
    • Arcuate scotomas (Bjerrum area, 10-20 degrees, arc-shaped)
    • Nasal step (Ronne nasal step)
    • Early inferior or superior arcuate defect (respects horizontal midline)
    • Localized defects without complete hemifield involvement
  • Global indices (approximations for mild):
    • Mean Deviation (MD): Better than -6 dB (mild loss); typically -2 to -6 dB in mild
    • Pattern Standard Deviation (PSD): Elevated (indicates localized loss)
    • Visual Field Index (VFI): >80-85% (percent of normal field remaining)
    • Glaucoma Hemifield Test (GHT): “Outside normal limits” or “Borderline”
  • Repeat VF essential: Single field insufficient; need 2-3 confirmatory fields

Central Corneal Thickness (Pachymetry) - IMPORTANT:

  • Ultrasonic or optical pachymetry
  • Normal CCT: ~545-555 microns (varies by ethnicity)
  • Thin CCT (<555 microns):
    • Underestimates true IOP (Goldmann tonometry less accurate)
    • Independent risk factor for glaucoma development and progression
    • Higher risk of conversion from OHT to glaucoma
  • Thick CCT (>588 microns):
    • Overestimates IOP
    • Lower glaucoma risk
  • Document for risk stratification

Optic Nerve Photography:

  • Stereophotography of optic disc
  • Baseline documentation for future comparison
  • Allows assessment of progression over time

Diagnostic Criteria for Mild Stage POAG:

Must Have ALL of the Following:

  1. Open anterior chamber angle on gonioscopy (distinguishes from angle-closure)
  2. Glaucomatous optic neuropathy:
    • Characteristic optic nerve damage (cupping, rim loss, RNFL defects, disc hemorrhages)
    • Or RNFL thinning on OCT consistent with glaucoma
  3. Corresponding visual field defects:
    • Glaucomatous pattern (arcuate, nasal step, paracentral scotomas)
    • Reproducible on repeat testing
  4. Mild stage specifically (ICD-10 criteria):
    • Visual field abnormalities present
    • Neither superior nor inferior hemifield completely involved
    • Central 5 degrees NOT involved
  5. Primary (not secondary to other cause):
    • No history of trauma, uveitis, steroid use, etc. causing elevated IOP
    • No identifiable secondary cause

Differential Diagnosis:

Must Rule Out:

  • Ocular hypertension (H40.05-):
    • Elevated IOP but NO optic nerve damage or VF loss
    • If damage present, it’s glaucoma, not OHT
  • Glaucoma suspect (H40.00-, H40.01-, H40.02-):
    • Suspicious findings but not meeting full glaucoma criteria
  • Normal-tension glaucoma (H40.12-):
    • Glaucomatous damage with IOP consistently ≤21 mmHg
    • Subset of POAG; if IOP documented as normal, use H40.12- instead of H40.11-
  • Angle-closure glaucoma (H40.2-):
    • Narrow or closed angle on gonioscopy
    • Different pathophysiology and treatment
  • Secondary glaucomas:
    • H40.3- (trauma)
    • H40.4- (inflammation/uveitis)
    • H40.5- (other eye disorders)
    • H40.6- (drug-induced, e.g., steroids)
    • H40.13- (pigmentary glaucoma)
    • H40.14- (pseudoexfoliation glaucoma)
  • Physiologic large cups:
    • Large C/D ratio but normal visual fields and RNFL
    • No progression over time
    • Often bilateral and symmetric
    • Large optic discs
  • Other optic neuropathies:
    • Anterior ischemic optic neuropathy (AION)
    • Optic neuritis
    • Compressive lesions
    • Different clinical presentation and pattern

Includes

This Code Encompasses:

  • Primary open-angle glaucoma affecting right eye at mild/early stage
  • Chronic simple glaucoma, right eye, mild stage
  • POAG with early glaucomatous damage, right eye
  • Glaucomatous optic neuropathy with early visual field loss, right eye
  • Open-angle glaucoma with mild cupping and rim loss, right eye
  • Glaucoma with IOP elevation (typical) and mild damage, right eye
  • Glaucoma meeting ICD-10 mild stage criteria (no complete hemifield involvement, central 5 degrees spared), right eye

Clinical Scenarios:

  • Patient with C/D 0.6, inferior RNFL thinning on OCT, early superior arcuate VF defect, right eye
  • Patient with elevated IOP (26 mmHg), glaucomatous optic nerve changes, paracentral scotomas not involving complete hemifield, right eye
  • Newly diagnosed POAG with early structural and functional damage, right eye
  • Patient converting from ocular hypertension to mild stage glaucoma, right eye
  • Glaucoma patient at early stage requiring IOP-lowering treatment, right eye

Stage Definition:

  • Mild = Stage 1 in ICD-10 4-stage system (Mild, Moderate, Severe, Indeterminate)
  • Visual field defects present but limited
  • Neither hemifield completely involved
  • Central fixation preserved
  • Corresponds approximately to MD better than -6 dB (though ICD-10 staging not based on MD)

Excludes

Excludes1 (Cannot Code Together - Mutually Exclusive):

At H40 Category Level:

  • H44.51- - Absolute glaucoma (end-stage, no light perception)
  • Q15.0 - Congenital glaucoma (infantile, developmental)
  • P15.3 - Traumatic glaucoma due to birth injury

Within H40.111 (Primary Open-Angle Glaucoma, Right Eye) - Different Stages:

  • H40.1110 - Primary open-angle glaucoma, right eye, stage UNSPECIFIED
  • H40.1112 - Primary open-angle glaucoma, right eye, MODERATE stage
  • H40.1113 - Primary open-angle glaucoma, right eye, SEVERE stage
  • H40.1119 - Primary open-angle glaucoma, right eye, INDETERMINATE stage

Within H40.111 (Right Eye) - Different Laterality:

  • H40.1121-1122-1123-1129 - Primary open-angle glaucoma, LEFT eye (various stages)
  • H40.1131-1132-1133-1139 - Primary open-angle glaucoma, BILATERAL (various stages)

Different Types of Glaucoma (Use Specific Code Instead):

  • H40.12- - Low-tension glaucoma / normal-tension glaucoma
    • If IOP documented as consistently ≤21 mmHg
  • H40.13- - Pigmentary glaucoma
    • If pigment dispersion syndrome with glaucoma
  • H40.14- - Capsular glaucoma with pseudoexfoliation
    • If pseudoexfoliation material present
  • H40.15- - Residual stage of open-angle glaucoma
    • If end-stage or status post-surgery
  • H40.20- - Unspecified primary angle-closure glaucoma
  • H40.21- - Acute angle-closure glaucoma
  • H40.22- - Chronic angle-closure glaucoma
    • If angle narrow/closed (not open-angle)
  • H40.3- - Glaucoma secondary to eye trauma
  • H40.4- - Glaucoma secondary to eye inflammation
  • H40.5- - Glaucoma secondary to other eye disorders
  • H40.6- - Glaucoma secondary to drugs (steroid-induced)
  • H40.8- - Other glaucoma (various types)

Pre-Glaucoma States (Different Diagnosis):

  • H40.05- - Ocular hypertension
    • If elevated IOP without damage
    • Once damage present, becomes glaucoma (H40.11-)
  • H40.00-, H40.01-, H40.02- - Glaucoma suspect
    • Suspicious findings but not confirmed glaucoma

Coding Rules:

  • Must specify stage when known (mild, moderate, severe, indeterminate, or unspecified)
  • Cannot code both eyes separately if bilateral - use bilateral code
  • Stage based on ICD-10 criteria (hemifield involvement, central 5 degrees), not other staging systems
  • Must meet diagnostic criteria for glaucoma (damage + VF loss), not just suspicious
  • Primary OAG only - if secondary cause, use appropriate H40.3-, H40.4-, H40.5-, H40.6- code

HCC Status

HCC Mapping: Does NOT typically map to an HCC Category

ICD-10 code H40.1111 (primary open-angle glaucoma, right eye, mild stage) does NOT typically map to a Hierarchical Condition Category (HCC) under the CMS-HCC risk adjustment model.

Why Not an HCC:

  • Glaucoma is chronic eye disease but does not predict high annual healthcare costs
  • Treatment relatively low-cost (eye drops, office visits, laser procedures)
  • Does not require intensive medical management or frequent hospitalizations
  • Vision loss from glaucoma not typically severe enough to impact HCC
  • Not among the ~86-115 HCC categories in CMS models

HCC Model Focus:

  • Chronic diseases requiring expensive ongoing management
  • Conditions with high resource utilization
  • Major organ system failures
  • Glaucoma does not meet these criteria

Glaucoma Characteristics (Non-HCC):

  • Chronic but manageable with medications/procedures
  • Office-based care (not hospital-based typically)
  • Medications moderate cost (generic drops available)
  • Laser procedures low-cost (outpatient)
  • Even surgical interventions relatively low-cost compared to HCC conditions
  • Annual healthcare costs modest

Vision Loss Exception:

  • Severe vision impairment or blindness from advanced glaucoma MAY map to HCC in specific model versions
  • H54.- codes (vision impairment/blindness) may map depending on severity and model
  • H40.1111 (mild stage) specifically NOT severe enough to map even if vision codes added

Clinical Implications:

  • Document H40.1111 for clinical accuracy and care quality
  • Important for glaucoma management and treatment justification
  • Not relevant for risk adjustment or HCC coding
  • Does not impact Medicare Advantage capitated payments
  • Code accurately for disease staging and progression tracking, not for HCC purposes

wRVU Status

Not Applicable - ICD-10 diagnosis codes do not have wRVU (work Relative Value Units) values.

wRVUs apply only to CPT procedure codes. ICD-10 codes document the diagnosis.

Related CPT Codes with wRVUs for Evaluation and Management of H40.1111:

Ophthalmology Examination:

  • 92002 - Intermediate, new patient: 0.92 wRVU
  • 92004 - Comprehensive, new patient: 1.50 wRVU
  • 92012 - Intermediate, established patient: 0.66 wRVU
  • 92014 - Comprehensive, established patient: 1.09 wRVU

Tonometry (IOP Measurement):

  • Typically included in comprehensive/intermediate exam
  • 92100 - Serial tonometry (multiple measurements same day): 0.14 wRVU

Gonioscopy:

  • 92020 - Gonioscopy: 0.64 wRVU
    • Essential for glaucoma diagnosis

Optic Nerve and RNFL Imaging:

  • 92133 - OCT optic nerve head with interpretation: 0.52 wRVU
    • Per eye; bilateral = 2 units
  • 92250 - Fundus photography with interpretation: 0.61 wRVU

Visual Field Testing:

  • 92081 - Visual field examination, limited: 0.22 wRVU
  • 92082 - Intermediate: 0.37 wRVU
  • 92083 - Extended examination (Humphrey 24-2, 30-2): 0.53 wRVU
    • Per eye; bilateral if both eyes tested

Pachymetry:

  • 76514 - Ophthalmic ultrasound, corneal pachymetry, unilateral or bilateral: 0.25 wRVU

Laser Treatment (If Indicated):

  • 65855 - Trabeculoplasty by laser surgery, one or more sessions (SLT or ALT): 3.84 wRVU

Surgical Treatment (If Medical/Laser Insufficient - Usually for Advanced Disease):

  • 66170 - Trabeculectomy ab externo: 14.87 wRVU
  • 66180 - Aqueous shunt to extraocular reservoir: 15.34 wRVU
  • 66183 - Insertion of anterior segment aqueous drainage device, without extraocular reservoir, external approach: 12.03 wRVU (MIGS procedures)
  • 66185 - Revision of aqueous shunt: 13.81 wRVU

Primary Care/Consultation:

  • 99201-99205 - New patient office visit: 0.92 to 3.17 wRVU
  • 99211-99215 - Established patient office visit: 0.18 to 1.92 wRVU

Assistant Surgeon Status

Not Applicable - ICD-10 diagnosis codes do not have assistant surgeon payment policies.

Note

If Glaucoma Surgery Required:
Assistant surgeon policies apply to surgical CPT codes (66170, 66180, etc.), not the diagnosis code H40.1111.

Glaucoma Surgery Assistant Surgeon:

  • Trabeculectomy (66170) and tube shunt procedures (66180) may qualify for assistant surgeon
  • MIGS procedures (66183) typically do not require assistant
  • Payer-specific policies vary
  • Medicare allows assistant for major glaucoma surgery if medically necessary

Mild Stage Glaucoma:

  • Surgery typically NOT needed at mild stage
  • Medical management (drops) or laser (SLT) first-line
  • Surgery reserved for moderate-severe or medication failure/intolerance

Common Modifiers

Not Applicable for Diagnosis Code

ICD-10 diagnosis codes do not use CPT modifiers. Modifiers are appended to CPT procedure codes.

Laterality Built Into Code:

  • H40.1111 = RIGHT eye, mild stage (laterality AND stage specified in code)
  • H40.1121 = LEFT eye, mild stage
  • H40.1131 = BILATERAL, mild stage
  • H40.1111No RT/LT modifiers needed on diagnosis code

When Billing CPT Procedures:
CPT codes may use modifiers:

  • -RT - Right side (use on procedure codes when examining/treating right eye only)
  • -LT - Left side (for left eye)
  • -50 - Bilateral procedure (if procedure performed both eyes same session)
    • Example: Visual fields both eyes = 92083-50
  • -26 - Professional component (for imaging interpretation only)
  • -TC - Technical component (for imaging equipment/performance only)
  • -79 - Unrelated procedure/service during postoperative period
  • -58 - Staged procedure during postoperative period

Common Associated Codes

Related ICD-10 Diagnosis Codes:

ICD-10 CodeDescriptionRelationship to H40.1111
H40.1110Primary OAG, right eye, stage unspecifiedSame eye, stage not documented
H40.1112Primary OAG, right eye, MODERATE stageProgression from mild to moderate
H40.1113Primary OAG, right eye, SEVERE stageProgression to advanced disease
H40.1119Primary OAG, right eye, INDETERMINATE stageStage cannot be determined
H40.1121Primary OAG, LEFT eye, mild stageContralateral eye mild
H40.1131Primary OAG, BILATERAL, mild stageBoth eyes mild (if symmetric)
H40.121-129Low-tension glaucoma (normal-tension)If IOP normal
H40.131-139Pigmentary glaucomaIf pigment dispersion present
H40.141-149Pseudoexfoliation glaucomaIf pseudoexfoliation material
H40.051Ocular hypertension, right eyePre-glaucoma state, may convert to H40.1111
H52.11Myopia, right eyeRisk factor for glaucoma
E11.9Type 2 diabetes mellitusRisk factor
I10Essential hypertensionRisk factor (controversial)
Z79.899Long-term use of other medicationsIf on chronic glaucoma drops
Z82.11Family history of glaucomaImportant risk factor
Z96.1Presence of intraocular lens (pseudophakic)If prior cataract surgery

Common Associated CPT Procedure Codes:

CPT CodeDescriptionWhen Used with H40.1111
92002Ophthalmological examination, intermediate, new patientInitial glaucoma evaluation
92004Ophthalmological examination, comprehensive, new patientComprehensive initial assessment
92012Intermediate, established patientFollow-up visits (typically every 3-6 months)
92014Comprehensive, established patientAnnual comprehensive exam
92020GonioscopyEssential for diagnosis (confirm open angle), repeated periodically
92100Serial tonometryMultiple IOP measurements
92133OCT optic nerve head with interpretationBaseline and serial monitoring (annual or every 6 months)
92134OCT retina (macular GCC)Ganglion cell assessment
92250Fundus photography with interpretationDocument optic nerve, serial comparison
92081Visual field limitedLess common for glaucoma
92083Visual field extended (Humphrey 24-2, 30-2)Essential for diagnosis and monitoring (every 6-12 months)
76514Corneal pachymetryBaseline CCT measurement
65855Trabeculoplasty by laser (SLT or ALT)Laser treatment to lower IOP (may be initial therapy or add-on)
66170Trabeculectomy ab externoIncisional surgery if medical/laser fail (rarely needed for mild)
66180Aqueous shunt to extraocular reservoirTube shunt surgery (rarely for mild)
66183Insertion anterior segment drainage device (MIGS)Minimally invasive surgery, may be done with cataract surgery
99201-99205Office visit, new patientPrimary care or initial consultation
99211-99215Office visit, established patientFollow-up management, medication adjustment

Medications for POAG (No Specific CPT Codes for Prescribing):

First-Line Agents:

  • Prostaglandin analogs (most effective, once-daily dosing):
    • Latanoprost (Xalatan)
    • Travoprost (Travatan)
    • Bimatoprost (Lumigan)
    • Tafluprost (Zioptan)
    • Latanoprostene bunod (Vyzulta)
  • Beta-blockers:
    • Timolol (generic, Timoptic)
    • Betaxolol (Betoptic)
    • Levobunolol (Betagan)
    • Carteolol (Ocupress)
  • Alpha-2 agonists:
    • Brimonidine (Alphagan)
    • Apraclonidine (Iopidine)
  • Carbonic anhydrase inhibitors:
    • Dorzolamide (Trusopt) - topical
    • Brinzolamide (Azopt) - topical
    • Acetazolamide (Diamox) - oral (rarely used now)
  • Rho kinase inhibitors:
    • Netarsudil (Rhopressa)
  • Combination medications:
    • Dorzolamide/Timolol (Cosopt)
    • Brimonidine/Timolol (Combigan)
    • Brinzolamide/Brimonidine (Simbrinza)
    • Netarsudil/Latanoprost (Rocklatan)

Treatment Algorithm for Mild POAG:

  1. Start with prostaglandin analog (first-line)
  2. Add second agent if inadequate IOP lowering
  3. Consider laser trabeculoplasty (SLT) as primary or adjunct
  4. Surgery if medical/laser fail or intolerant (rare for mild)

Code Tree/Hierarchy

ICD-10-CM Chapter: 7 - Diseases of the Eye and Adnexa (H00-H59)

Block: H40-H42 - Glaucoma

Category: H40 - Glaucoma

Structure:

H40 - Glaucoma
│
├── H40.0 - Glaucoma suspect
├── H40.1 - Open-angle glaucoma ◄ Current Subcategory
│   │
│   ├── H40.10 - Unspecified open-angle glaucoma
│   │
│   ├── H40.11 - Primary open-angle glaucoma ◄ Current Group
│   │   │
│   │   ├── H40.111 - Primary open-angle glaucoma, right eye ◄ Current Code Group
│   │   │   ├── H40.1110 - Stage unspecified
│   │   │   ├── H40.1111 - Mild stage ◄ CURRENT CODE
│   │   │   ├── H40.1112 - Moderate stage
│   │   │   ├── H40.1113 - Severe stage
│   │   │   └── H40.1119 - Indeterminate stage
│   │   │
│   │   ├── H40.112 - Primary open-angle glaucoma, left eye
│   │   │   ├── H40.1120 - Stage unspecified
│   │   │   ├── H40.1121 - Mild stage
│   │   │   ├── H40.1122 - Moderate stage
│   │   │   ├── H40.1123 - Severe stage
│   │   │   └── H40.1129 - Indeterminate stage
│   │   │
│   │   ├── H40.113 - Primary open-angle glaucoma, bilateral
│   │   │   ├── H40.1130 - Stage unspecified
│   │   │   ├── H40.1131 - Mild stage
│   │   │   ├── H40.1132 - Moderate stage
│   │   │   ├── H40.1133 - Severe stage
│   │   │   └── H40.1139 - Indeterminate stage
│   │   │
│   │   └── H40.119 - Primary open-angle glaucoma, unspecified eye
│   │       ├── H40.1190 - Stage unspecified
│   │       ├── H40.1191 - Mild stage
│   │       ├── H40.1192 - Moderate stage
│   │       ├── H40.1193 - Severe stage
│   │       └── H40.1199 - Indeterminate stage
│   │
│   ├── H40.12 - Low-tension glaucoma (normal-tension)
│   ├── H40.13 - Pigmentary glaucoma
│   ├── H40.14 - Capsular glaucoma with pseudoexfoliation
│   └── H40.15 - Residual stage of open-angle glaucoma
│
├── H40.2 - Primary angle-closure glaucoma
├── H40.3 - Glaucoma secondary to eye trauma
├── H40.4 - Glaucoma secondary to eye inflammation
├── H40.5 - Glaucoma secondary to other eye disorders
├── H40.6 - Glaucoma secondary to drugs
├── H40.8 - Other glaucoma
└── H40.9 - Unspecified glaucoma

ICD-10 Glaucoma Staging System (4 Stages):

Stage CodeStage NameICD-10 Definition
-1MildOptic nerve abnormalities + VF abnormalities present, but neither hemifield completely involved AND central 5° NOT involved
-2ModerateOptic nerve abnormalities + VF abnormalities in ONE hemifield (superior OR inferior) but NOT both, AND central 5° NOT involved
-3SevereOptic nerve abnormalities + VF abnormalities in BOTH hemifields (superior AND inferior) AND/OR central 5° IS involved
-9IndeterminateGlaucoma confirmed but stage cannot be determined (inadequate VF testing, media opacity, etc.)
-0UnspecifiedGlaucoma present but stage not documented

Code Selection Decision Tree:

Patient Has Glaucoma?
│
├── What TYPE of glaucoma?
│   │
│   ├── PRIMARY OPEN-ANGLE GLAUCOMA → H40.11- series
│   ├── Low-tension/Normal-tension glaucoma → H40.12- series
│   ├── Pigmentary glaucoma → H40.13- series
│   ├── Pseudoexfoliation glaucoma → H40.14- series
│   ├── Angle-closure glaucoma → H40.2- series
│   ├── Secondary glaucoma (trauma, inflammation, drugs) → H40.3-, H40.4-, H40.6-
│   └── Other → H40.8-, H40.9
│
└── For PRIMARY OPEN-ANGLE GLAUCOMA:
    │
    ├── Which EYE affected?
    │   ├── Right eye only → H40.111-
    │   ├── Left eye only → H40.112-
    │   ├── Bilateral → H40.113-
    │   └── Unspecified → H40.119-
    │
    └── What STAGE (right eye example)?
        ├── MILD stage:
        │   - VF defects present
        │   - Neither hemifield completely involved
        │   - Central 5° spared
        │   → H40.1111 ◄ CURRENT CODE
        │
        ├── MODERATE stage:
        │   - VF defects in ONE hemifield (superior OR inferior)
        │   - Central 5° spared
        │   → H40.1112
        │
        ├── SEVERE stage:
        │   - VF defects in BOTH hemifields AND/OR
        │   - Central 5° involved
        │   → H40.1113
        │
        ├── INDETERMINATE stage:
        │   - Glaucoma confirmed but stage cannot be determined
        │   → H40.1119
        │
        └── Stage UNSPECIFIED:
            - Stage not documented
            → H40.1110

Comparison to Other Staging Systems (For Reference):

ICD-10 staging differs from clinical trial staging systems:

SystemMild/EarlyModerateSevere/Advanced
ICD-10Neither hemifield involved; central 5° sparedOne hemifield involved; central 5° sparedBoth hemifields involved OR central 5° involved
Hodapp-Parrish-AndersonMD better than -6 dB; <25% points <5%, <10 points <1%MD -6 to -12 dB; <50% points <5%, <25% points <1%MD worse than -12 dB; >75% points <5%, >50% points <1%
Mills (GSS)MD better than -6 dBMD -6 to -12 dBMD worse than -12 dB
Visual Field IndexVFI >85%VFI 70-85%VFI <70%

Note

ICD-10 staging based on topographic pattern (hemifield involvement, central involvement), NOT global indices (MD, PSD, VFI). Coders must use ICD-10 criteria, not other systems.

Coding Examples

Example 1: New Diagnosis of Mild Primary Open-Angle Glaucoma - Right Eye

Clinical Scenario:
62-year-old African American male presents for routine eye examination. No visual complaints.

History:

  • No symptoms
  • Family history: Father had glaucoma
  • Medical history: Type 2 diabetes (well-controlled), hypertension
  • Never had glaucoma treatment

Examination:

  • Visual acuity: 20/20 both eyes
  • IOP:
    • Right eye: 26 mmHg
    • Left eye: 18 mmHg
  • Gonioscopy: Wide open angles bilaterally (Shaffer grade 3-4)
  • Dilated fundus examination - Right eye:
    • Optic nerve: Vertical C/D 0.6, horizontal C/D 0.5
    • Neuroretinal rim: Inferior thinning noted
    • No disc hemorrhages
    • RNFL: Inferior wedge defect visible
  • Left eye: Optic nerve normal, C/D 0.3
  • OCT RNFL - Right eye:
    • Average thickness 82 microns (below normal; red zone)
    • Inferior quadrant 68 microns (significantly reduced)
  • Left eye: RNFL normal
  • Visual Field (Humphrey 24-2) - Right eye:
    • Early superior arcuate scotoma (corresponding to inferior nerve damage)
    • Defects in superior hemifield ONLY
    • Inferior hemifield normal
    • Central 5 degrees INTACT
    • MD -3.5 dB, PSD 5.2 dB, GHT outside normal limits
    • Reliable test
  • Left eye: Normal visual field
  • Pachymetry:
    • Right eye: 532 microns (thin - risk factor)
    • Left eye: 540 microns

Assessment:

  • Primary open-angle glaucoma, right eye, MILD STAGE
  • Evidence of glaucomatous optic neuropathy with corresponding visual field loss
  • ICD-10 MILD stage criteria met:
    • VF defects present (superior arcuate scotoma)
    • Superior hemifield partially involved, but NOT completely
    • Inferior hemifield normal
    • Central 5 degrees intact
  • Left eye: Normal (no glaucoma)

Plan:

  • Diagnose POAG right eye, mild stage
  • Start latanoprost 0.005% right eye nightly
  • Target IOP <20 mmHg (20-25% reduction)
  • Baseline documentation complete (VF, OCT, photos)
  • Return in 4-6 weeks to assess IOP response
  • Repeat VF and OCT in 6 months
  • Patient education: Chronic disease, need lifelong treatment and monitoring, excellent prognosis with treatment

ICD-10-CM Coding:

  • H40.1111 - Primary open-angle glaucoma, right eye, mild stage (PRIMARY)
  • E11.9 - Type 2 diabetes mellitus without complications
  • I10 - Essential hypertension
  • Z82.11 - Family history of glaucoma

CPT Coding:

  • 92004 - Comprehensive ophthalmological examination, new patient (OR 92014 if established)
  • 92020 - Gonioscopy
  • 92083 - Visual field examination, extended (Humphrey 24-2) - bilateral
  • 92133 - OCT optic nerve head - bilateral
  • 76514 - Corneal pachymetry

Rationale:
H40.1111 appropriate as patient meets all criteria for primary open-angle glaucoma (open angle, glaucomatous optic nerve damage, corresponding VF loss) in right eye at mild stage per ICD-10 criteria (neither hemifield completely involved, central 5 degrees spared). Treatment initiated to lower IOP and prevent progression.

Example 2: Mild Stage POAG Progressing to Moderate Stage

Clinical Scenario:
68-year-old patient with known mild POAG right eye, diagnosed 3 years ago, returns for follow-up.

Prior Diagnosis: H40.1111 - Primary OAG, right eye, mild stage (3 years ago)

Current History:

  • On latanoprost right eye nightly for 3 years
  • Generally compliant with drops
  • No symptoms

Current Examination:

  • Visual acuity: 20/25 right eye, 20/20 left eye
  • IOP: Right eye 16 mmHg (well-controlled on latanoprost), Left eye 15 mmHg
  • Dilated fundus - Right eye:
    • C/D now 0.7 (was 0.6 three years ago) - PROGRESSION
    • Inferior rim thinner than prior
    • Superior rim now also shows thinning
  • OCT RNFL - Right eye:
    • Average 76 microns (was 82 microns three years ago) - PROGRESSION
    • Inferior quadrant 58 microns (was 68 microns)
    • Superior quadrant now 70 microns (was 88 microns) - new thinning
  • Visual Field - Right eye:
    • Progression: Superior arcuate scotoma now COMPLETE (entire superior hemifield involved)
    • Inferior hemifield STILL NORMAL
    • Central 5 degrees STILL INTACT
    • MD -8.2 dB (was -3.5 dB three years ago)
    • Confirms progression
  • Left eye: Stable, normal

Assessment:

  • Primary open-angle glaucoma, right eye, MODERATE STAGE (CHANGED from mild)
  • Glaucoma progression despite treatment
  • ICD-10 MODERATE stage criteria now met:
    • VF defects in ONE complete hemifield (superior)
    • Inferior hemifield normal
    • Central 5 degrees intact
  • Diagnosis code MUST CHANGE from H40.1111 to H40.1112

Plan:

  • Update diagnosis: MODERATE stage glaucoma
  • Despite IOP control (16 mmHg), progression occurred
  • Lower target IOP: Now <14 mmHg
  • Add second medication: Dorzolamide/timolol (Cosopt) twice daily right eye
  • Consider laser trabeculoplasty (SLT) as adjunct
  • More frequent monitoring: VF and OCT every 4-6 months
  • May need surgery if progression continues

ICD-10-CM Coding - UPDATED:

  • H40.1112 - Primary open-angle glaucoma, right eye, MODERATE stage (CHANGED from H40.1111)
  • Z79.899 - Long-term use of medications (glaucoma drops)
  • E11.9 - Diabetes (if still applicable)

CPT Coding:

  • 92014 - Comprehensive examination
  • 92083 - Visual fields
  • 92133 - OCT
  • 92250 - Fundus photography (serial comparison)

Rationale:
Diagnosis code MUST be updated from mild (H40.1111) to moderate (H40.1112) as patient now meets ICD-10 moderate stage criteria (one complete hemifield involved). Demonstrates disease progression despite treatment. More aggressive IOP lowering needed.

Example 3: Bilateral Asymmetric POAG - Right Eye Mild, Left Eye Worse

Clinical Scenario:
70-year-old with bilateral glaucoma, asymmetric severity.

Examination:

  • Right eye:
    • IOP 18 mmHg on latanoprost
    • C/D 0.6
    • VF: Early superior arcuate defect
    • Neither hemifield completely involved
    • Central 5 degrees intact
    • MILD STAGE
  • Left eye:
    • IOP 20 mmHg on latanoprost + dorzolamide/timolol
    • C/D 0.8
    • VF: Complete superior AND inferior hemifield defects
    • Central 5 degrees INVOLVED (central island of vision only)
    • SEVERE STAGE

Assessment:

  • Primary open-angle glaucoma, BILATERAL, but asymmetric severity
  • Right eye: Mild stage
  • Left eye: Severe stage

Incorrect Coding:

  • H40.1131 - Bilateral, mild stage (WRONG - not symmetric mild)
  • H40.1133 - Bilateral, severe stage (WRONG - not symmetric severe)

Correct Coding:

  • H40.1111 - Primary OAG, right eye, mild stage
  • H40.1123 - Primary OAG, left eye, severe stage
  • Code EACH EYE SEPARATELY with appropriate stage when asymmetric

Rationale:
When bilateral glaucoma with ASYMMETRIC staging, must code each eye separately with its own stage. Cannot use bilateral code (H40.113-) unless both eyes are same stage. This allows accurate documentation of disease severity in each eye.

Example 4: Normal-Tension Glaucoma vs Primary OAG - Coding Difference

Clinical Scenario A - Primary OAG with Elevated IOP:

  • IOP: 26 mmHg right eye (elevated)
  • Glaucomatous optic nerve damage
  • VF defects, mild stage
  • Code: H40.1111 - Primary open-angle glaucoma, right eye, mild stage

Clinical Scenario B - Normal-Tension Glaucoma:

  • IOP: 18 mmHg right eye (NORMAL - consistently <21 mmHg on multiple visits)
  • Glaucomatous optic nerve damage (identical appearance to Scenario A)
  • VF defects, mild stage (identical to Scenario A)
  • Code: H40.1211 - Low-tension glaucoma, right eye, mild stage (DIFFERENT CODE)

Rationale:
Normal-tension glaucoma (NTG) is subset of POAG where IOP is CONSISTENTLY in normal range (<21 mmHg). If IOP documented as normal, use H40.12- series (low-tension glaucoma) instead of H40.11- series. Clinical presentation and damage pattern identical, but IOP distinguishes coding. Treatment similar but NTG may require even lower target IOP.

Example 5: Glaucoma Suspect Converting to Mild POAG

Clinical Scenario - Initial Visit (2 years ago):

  • IOP 24 mmHg right eye
  • Suspicious optic nerve (C/D 0.55, borderline)
  • Visual fields NORMAL
  • OCT RNFL borderline
  • Diagnosis: Ocular hypertension, right eye
  • Code (2 years ago): H40.051

Current Visit (Now):

  • IOP 22 mmHg right eye (on latanoprost)
  • C/D now 0.65 (progression)
  • NEW visual field defects: Early superior arcuate scotoma (reproducible on repeat testing)
  • NEW RNFL thinning on OCT: Inferior thinning confirmed
  • CONVERSION from ocular hypertension to glaucoma

Current Assessment:

  • Primary open-angle glaucoma, right eye, mild stage (NEW DIAGNOSIS - converted from OHT)
  • Diagnosis code MUST CHANGE from H40.051 to H40.1111

Current Coding:

  • H40.1111 - Primary OAG, right eye, mild stage (CHANGED)
  • Z79.899 - Long-term medication use (already on latanoprost)

Plan:

  • Diagnosis changed to glaucoma
  • Continue latanoprost, may need additional medication
  • Closer monitoring (VF/OCT every 6 months)
  • Patient counseled on conversion to glaucoma

Rationale:
Once visual field defects and/or optic nerve progression documented, patient converts from ocular hypertension (H40.051) to glaucoma (H40.1111). Demonstrates disease progression from pre-glaucoma to glaucoma. Change in diagnosis code essential.

Example 6: Pseudoexfoliation Glaucoma - NOT Primary OAG

Clinical Scenario:
72-year-old with glaucomatous damage, mild stage.

Examination:

  • IOP 28 mmHg right eye
  • C/D 0.6
  • VF: Early defects, mild stage criteria met
  • Slit lamp:
    • White, flaky pseudoexfoliative material on lens capsule
    • Pseudoexfoliative material on pupil margin
    • Increased trabecular meshwork pigmentation
  • Gonioscopy: Open angle with heavy pigmentation

Incorrect Coding:

  • H40.1111 - Primary OAG (WRONG - pseudoexfoliation present)

Correct Coding:

  • H40.1411 - Capsular glaucoma with pseudoexfoliation of lens, right eye, mild stage

Rationale:
Presence of pseudoexfoliation material makes this pseudoexfoliation glaucoma (H40.14-), NOT primary open-angle glaucoma (H40.11-). Even though angle is open and damage pattern similar, specific cause (pseudoexfoliation) identified, so use specific code. This is important because pseudoexfoliation glaucoma often more aggressive than primary OAG.

Example 7: Stage Indeterminate Due to Media Opacity

Clinical Scenario:
78-year-old with known glaucoma, dense cataract.

Examination:

  • IOP 24 mmHg right eye
  • C/D 0.7 (difficult to visualize through cataract)
  • Dense cataract obscuring optic nerve view
  • Visual field: Unreliable due to cataract (cannot see targets)
  • OCT: Unable to obtain good quality images (media opacity)
  • Glaucoma clearly present (prior documentation) but CANNOT determine stage currently

Coding:

  • H40.1119 - Primary OAG, right eye, INDETERMINATE stage
  • H25.9 - Unspecified age-related cataract, right eye

Plan:

  • Cataract surgery recommended
  • Will re-stage glaucoma after cataract removal and vision cleared
  • May also treat glaucoma at time of cataract surgery (combined procedure)

Rationale:
When glaucoma confirmed but staging cannot be determined (inadequate visual fields, media opacity, patient unable to perform testing), use INDETERMINATE stage code (-9). After cataract surgery and successful VF testing, update to appropriate stage (mild, moderate, or severe).

Documentation Requirements

Essential Documentation for H40.1111:

1. Confirm Diagnosis of Primary Open-Angle Glaucoma:

Must document ALL of the following:

A. Open Anterior Chamber Angle (ESSENTIAL):

  • Gonioscopy performed and documented
  • “Anterior chamber angle open 360 degrees bilaterally”
  • Shaffer grade 3-4 or equivalent
  • No peripheral anterior synechiae
  • No angle closure

Example: “Gonioscopy performed: Anterior chamber angle open 360 degrees bilaterally, Shaffer grade 3-4. All angle structures visible including trabecular meshwork, scleral spur, and ciliary body band. No peripheral anterior synechiae. Trabecular meshwork shows increased pigmentation.”

B. Glaucomatous Optic Neuropathy (ESSENTIAL):
Must document optic nerve damage characteristic of glaucoma:

  • Cup-to-disc ratio: “Right eye vertical C/D 0.6, horizontal C/D 0.5”
  • Neuroretinal rim assessment:
    • “Inferior rim thinning noted”
    • “ISNT rule breakdown with inferior rim thinner than expected”
    • “Focal notching at 7 o’clock position”
  • RNFL defects: “Inferior RNFL wedge defect visible on fundoscopy”
  • Disc hemorrhages: “Disc hemorrhage noted at 6 o’clock” (if present)
  • Peripapillary atrophy: Document if present

Example: “Dilated fundus examination right eye: Optic nerve shows vertical cup-to-disc ratio 0.6 and horizontal C/D 0.5, representing increased cupping compared to fellow eye. Neuroretinal rim demonstrates inferior thinning with focal notching at 7 o’clock position. Inferior RNFL wedge defect visible. No disc hemorrhages currently. Findings consistent with glaucomatous optic neuropathy.”

C. Corresponding Visual Field Defects (ESSENTIAL):
Must document:

  • Visual field testing performed: “Humphrey 24-2 SITA Standard”
  • Glaucomatous field defects present:
    • Describe pattern: “Superior arcuate scotoma”
    • Location: “10-20 degrees from fixation in superior hemifield”
    • Reproducible: “Confirmed on repeat testing”
  • Global indices:
    • MD: “-3.5 dB”
    • PSD: “5.2 dB elevated”
    • GHT: “Outside normal limits”
  • Reliability: “Fixation losses 5%, false positives 2%, false negatives 8% - reliable test”

Example: “Humphrey visual field 24-2 SITA Standard right eye demonstrates early superior arcuate scotoma in the 10-20 degree range from fixation, respecting the horizontal midline. Pattern consistent with glaucomatous visual field loss corresponding to inferior optic nerve fiber damage. Mean deviation -3.5 dB, pattern standard deviation 5.2 dB (elevated), glaucoma hemifield test outside normal limits. Reliable test (fixation losses 5%). Visual field defect reproducible on prior testing 6 months ago.”

2. Document MILD STAGE Specifically (ESSENTIAL for H40.1111):

Must document that ICD-10 MILD stage criteria are met:

ICD-10 MILD Stage Criteria:

  • Visual field abnormalities present (confirmed above)
  • NEITHER superior NOR inferior hemifield completely involved
    • “Superior hemifield partially involved with arcuate defect”
    • “Inferior hemifield normal”
  • Central 5 degrees of fixation NOT involved
    • “Central 5 degrees intact”
    • “Fixation preserved”

Example Statement: “ICD-10 glaucoma staging assessment: Patient meets criteria for MILD stage glaucoma as visual field defects are present in superior hemifield but do NOT completely involve the entire hemifield, inferior hemifield remains normal, and central 5 degrees of fixation remain intact.”

3. Document Right Eye Affected:

  • Must clearly specify “right eye” or “OD”
  • Document findings for each eye separately if bilateral disease
  • If left eye also affected, code separately

4. OCT Documentation (Highly Recommended):
While not strictly required for ICD-10 coding, OCT documentation strengthens diagnosis:

  • “OCT RNFL right eye: Average thickness 82 microns (below normal), inferior quadrant 68 microns (red zone indicating significant thinning)”
  • “Ganglion cell complex analysis shows thinning corresponding to visual field defect”

5. IOP Documentation:

  • Document IOP at each visit
  • “IOP right eye 26 mmHg by Goldmann applanation tonometry”
  • Note: IOP may be elevated or normal in POAG; if consistently normal (<21), consider H40.12- (normal-tension glaucoma) instead

6. Central Corneal Thickness:

  • “Central corneal thickness right eye 532 microns (thin, risk factor for progression)”

7. Rule Out Secondary Causes:

  • Document absence of:
    • Pseudoexfoliation material (if present, use H40.14- code)
    • Pigment dispersion (if pigmentary glaucoma, use H40.13-)
    • Trauma history (if traumatic, use H40.3-)
    • Uveitis (if inflammatory, use H40.4-)
    • Steroid use (if drug-induced, use H40.6-)
  • Statement: “No pseudoexfoliation material visualized on slit lamp examination. No evidence of pigment dispersion syndrome. No history of ocular trauma, inflammation, or chronic steroid use. Diagnosis consistent with primary open-angle glaucoma.”

8. Assessment and Plan:

  • Diagnosis: “Primary open-angle glaucoma, right eye, mild stage”
  • Treatment plan:
    • Medication: “Start latanoprost 0.005% right eye nightly”
    • Target IOP: “Target IOP <20 mmHg (20-25% reduction from baseline)”
    • Alternative: “Selective laser trabeculoplasty recommended as primary therapy”
  • Monitoring plan:
    • “Follow-up in 4-6 weeks to assess IOP response”
    • “Repeat visual fields and OCT in 6 months”
    • “Annual comprehensive examinations with VF and OCT monitoring”
  • Patient education: “Patient counseled on chronic progressive nature of glaucoma, importance of daily medication adherence, need for lifelong monitoring, and excellent prognosis with treatment to prevent vision loss”

Complete Documentation Example (Supports H40.1111):

“62-year-old African American male presents for routine comprehensive eye examination. Patient reports no visual complaints or symptoms. Family history significant for glaucoma in father. Medical history includes type 2 diabetes mellitus (well-controlled, HbA1c 6.8%) and hypertension (controlled on lisinopril).

Examination: Best-corrected visual acuity 20/20 right eye, 20/20 left eye. Intraocular pressure by Goldmann applanation tonometry: right eye 26 mmHg, left eye 18 mmHg. Pachymetry: Right eye central corneal thickness 532 microns (thin), left eye 540 microns.

Gonioscopy: Anterior chamber angle open 360 degrees bilaterally, Shaffer grade 3-4. All angle structures visible. Trabecular meshwork shows moderate pigmentation bilaterally. No peripheral anterior synechiae. No angle recession. Findings consistent with open-angle anatomy.

Dilated fundus examination: Right eye optic nerve demonstrates vertical cup-to-disc ratio 0.6 and horizontal cup-to-disc ratio 0.5, significantly increased compared to left eye (C/D 0.3). Neuroretinal rim shows inferior thinning with focal notching. Inferior retinal nerve fiber layer wedge defect visible on red-free photography. No disc hemorrhages currently present. Beta zone peripapillary atrophy noted. Findings consistent with glaucomatous optic neuropathy. Left eye optic nerve appears healthy with normal cup-to-disc ratio 0.3 and intact neuroretinal rim.

Optical coherence tomography (OCT) RNFL analysis: Right eye average thickness 82 microns (below normal range, red zone), inferior quadrant 68 microns (significantly reduced, red zone). Pattern consistent with inferior RNFL loss corresponding to superior visual field defect. Left eye RNFL within normal limits, average 98 microns.

Humphrey visual field 24-2 SITA Standard: Right eye demonstrates reproducible early superior arcuate scotoma in the 10-20 degree range from fixation, respecting horizontal midline and corresponding to inferior optic nerve fiber damage. Mean deviation -3.5 dB, pattern standard deviation 5.2 dB (elevated), visual field index 92%, glaucoma hemifield test outside normal limits. Reliable test with fixation losses 5%, false positives 2%, false negatives 8%. Central 5 degrees of fixation remain intact. Superior hemifield partially involved but NOT completely involved. Inferior hemifield normal. Left eye visual field within normal limits.

Slit lamp examination: No pseudoexfoliation material visualized. No evidence of pigment dispersion syndrome. Anterior chambers deep and quiet bilaterally. No cells or flare. Lenses show early nuclear sclerotic changes bilaterally. No other anterior segment abnormalities.

Assessment: Primary open-angle glaucoma, right eye, MILD STAGE. Patient meets all diagnostic criteria for primary open-angle glaucoma including open anterior chamber angle on gonioscopy, characteristic glaucomatous optic neuropathy with inferior rim loss and RNFL thinning, and corresponding superior visual field defect. ICD-10 staging criteria for MILD stage confirmed: visual field defects present but neither hemifield completely involved and central 5 degrees of fixation preserved. Risk factors include elevated intraocular pressure (26 mmHg right eye), African American race, positive family history, thin central corneal thickness (532 microns), age 62, and type 2 diabetes. Left eye currently normal without evidence of glaucoma.

Plan: Initiate treatment with topical prostaglandin analog latanoprost 0.005% one drop right eye nightly. Target intraocular pressure less than 20 mmHg (representing approximately 25% reduction from baseline). Patient educated extensively regarding chronic progressive nature of glaucoma, necessity of daily medication adherence, importance of lifelong monitoring, and excellent prognosis with appropriate treatment to prevent vision loss. Instructed to report any side effects from medication including redness, irritation, or changes in eyelash growth. Return visit in 4-6 weeks to assess intraocular pressure response to latanoprost therapy. Will obtain repeat visual fields and OCT imaging in 6 months to establish baseline rate of progression and monitor for stability on treatment. Annual comprehensive examinations with gonioscopy, optic nerve evaluation, visual field testing, and OCT monitoring planned long-term. Patient understands diagnosis, treatment plan, and importance of follow-up. All questions answered.

ICD-10: H40.1111 (Primary open-angle glaucoma, right eye, mild stage), E11.9 (Type 2 diabetes mellitus), I10 (Essential hypertension), Z82.11 (Family history of glaucoma)”

Insufficient Documentation Examples:

Example 1 - Insufficient:
“Patient has glaucoma right eye.”

  • Missing: Open angle confirmation (gonioscopy)
  • Missing: Optic nerve description (C/D, rim assessment)
  • Missing: Visual field results
  • Missing: Stage documentation
  • Cannot code H40.1111 without complete documentation

Example 2 - Insufficient:
“IOP 26 right eye, large cup, mild glaucoma.”

  • Missing: Gonioscopy (must confirm open angle)
  • Missing: Quantitative C/D ratio
  • Missing: Visual field documentation
  • Missing: ICD-10 staging criteria assessment
  • “Mild” mentioned but not documented per ICD-10 criteria
  • Insufficient detail

Example 3 - Insufficient:
“Glaucoma right eye with visual field defects.”

  • Missing: Specific VF pattern and extent
  • Missing: Staging (mild, moderate, severe?)
  • Missing: Optic nerve description
  • Missing: Type of glaucoma (primary OAG vs other?)
  • Cannot assign specific stage code

When to Query Physician:

Query for Stage:
“Documentation confirms primary open-angle glaucoma right eye. Please specify stage per ICD-10 criteria:

  • Mild: Neither hemifield completely involved, central 5° spared
  • Moderate: One hemifield involved, central 5° spared
  • Severe: Both hemifields involved OR central 5° involved
  • Indeterminate: Cannot determine stage
  • Or provide visual field pattern description for coding determination”

Query for Open vs Closed Angle:
“Documentation notes glaucoma right eye. Was gonioscopy performed? Is anterior chamber angle open or closed? This determines whether to code as open-angle (H40.11-) or angle-closure (H40.2-) glaucoma.”

Query for Primary vs Secondary:
“Documentation notes glaucoma. Please clarify: Is this PRIMARY open-angle glaucoma or secondary glaucoma from trauma, inflammation, steroids, pseudoexfoliation, or other cause? Presence of secondary cause changes code selection.”

Query for Laterality:
“Documentation mentions glaucoma mild stage. Which eye is affected: right eye, left eye, or bilateral? If bilateral, are both eyes same stage or different stages?”

Billing and Coding Considerations

When to Use H40.1111:

Appropriate Use:

  • Confirmed diagnosis of primary open-angle glaucoma
  • Right eye specifically affected
  • Mild stage per ICD-10 criteria (neither hemifield complete, central 5° spared)
  • ALL diagnostic criteria met (open angle, optic nerve damage, VF loss)
  • Primary (not secondary to other cause)

Medical Necessity:

H40.1111 Supports:

  • Comprehensive ophthalmologic examinations every 3-6 months initially, then annually if stable
  • Gonioscopy (initial diagnosis, periodic re-evaluation)
  • Visual field testing (baseline, every 6-12 months for monitoring)
  • OCT imaging (baseline, every 6-12 months)
  • Optic nerve photography (baseline, annual or as needed)
  • IOP measurements (each visit)
  • Pachymetry (baseline)
  • Medical treatment:
    • Topical IOP-lowering medications (prostaglandin analogs, beta-blockers, alpha-agonists, CAIs, rho kinase inhibitors)
    • Multiple medications if needed for IOP control
  • Laser trabeculoplasty (SLT or ALT):
    • As primary therapy or adjunct to medications
    • Supported by mild stage glaucoma diagnosis
  • Surgery (if medical/laser insufficient - rare for mild stage):
    • Trabeculectomy, tube shunt, MIGS procedures
    • Usually reserved for moderate-severe or medication failure
    • Must document medical necessity (failed medical therapy, intolerance, progression)

Monitoring Frequency:

  • Newly diagnosed: Every 3-4 months until stable on treatment
  • Stable on treatment: Every 6-12 months
  • Progression concern: Every 3-6 months
  • More frequent if unstable IOP or evidence of progression

Payer Considerations:

Medicare:

  • Covers medically necessary glaucoma care
  • Comprehensive exams covered
  • Visual fields covered annually (92083)
  • OCT covered annually for glaucoma monitoring (92133)
  • Gonioscopy covered (92020)
  • Glaucoma medications covered under Part D
  • Laser trabeculoplasty covered
  • Surgery covered if medically necessary

Commercial Insurance:

  • Generally follows Medicare guidelines
  • Prior authorization may be required for:
    • Frequent visual field testing (more than annual)
    • Multiple OCT scans per year
    • Laser procedures
    • Surgery
  • Document medical necessity for testing frequency
  • Medication coverage variable (formulary restrictions, step therapy, prior authorization)

Diagnosis-Related Billing:

  • Link all testing to glaucoma diagnosis (H40.1111)
  • VF and OCT for glaucoma monitoring clearly documented
  • Not screening, but disease monitoring
  • Medical necessity clear with glaucoma diagnosis

Treatment Documentation:

  • Medications: Document name, strength, frequency, eye(s) treated
  • IOP response: Document IOP before and after treatment initiation
  • Target IOP: Document individualized target IOP and rationale
  • Compliance: Document medication adherence discussion
  • Side effects: Document any adverse effects and management

Common Billing Errors:

  1. Not specifying stage:
    • Using H40.1110 (stage unspecified) when stage documented
    • Should use H40.1111 (mild), H40.1112 (moderate), or H40.1113 (severe)
    • Always code to highest level of specificity available
    • Review visual field documentation to determine stage
  2. Not updating stage when disease progresses:
    • Continuing to code H40.1111 (mild) when patient has progressed to moderate or severe
    • Must review current visual fields and update stage code accordingly
    • Progression from mild → moderate → severe requires code change
    • Example: Patient diagnosed mild 3 years ago now has complete hemifield involvement = code H40.1112 (moderate), not H40.1111
  3. Using bilateral code for asymmetric disease:
    • Coding H40.1131 (bilateral, mild stage) when right eye is mild but left eye is moderate or severe
    • When stages differ between eyes, code each eye separately:
      • H40.1111 (right eye, mild) + H40.1122 (left eye, moderate)
    • Only use bilateral code (H40.113-) when both eyes are same stage
  4. Confusing staging systems:
    • Using Hodapp-Parrish-Anderson criteria or MD values instead of ICD-10 criteria
    • ICD-10 staging based on hemifield involvement and central 5°, NOT mean deviation
    • Must apply ICD-10 definitions, not clinical trial staging systems
    • Document which hemifields involved and whether central 5° affected
  5. Coding primary OAG when secondary cause present:
    • Using H40.1111 when pseudoexfoliation material documented → should be H40.1411 (pseudoexfoliation glaucoma)
    • Using H40.1111 when pigment dispersion syndrome present → should be H40.1311 (pigmentary glaucoma)
    • Using H40.1111 with steroid-induced glaucoma → should be H40.6- (drug-induced)
    • Using H40.1111 with trauma history → should be H40.3- (traumatic glaucoma)
    • Review documentation for secondary causes before coding primary OAG
  6. Coding glaucoma when only ocular hypertension:
    • Using H40.1111 when patient has elevated IOP but NO optic nerve damage or visual field loss
    • Must have BOTH structural damage AND functional loss for glaucoma diagnosis
    • If only elevated IOP without damage = H40.051 (ocular hypertension), not glaucoma
    • Cannot code glaucoma based on IOP alone
  7. Using H40.11- when IOP consistently normal:
    • Coding H40.1111 (primary OAG) when documentation states IOP consistently ≤21 mmHg
    • If IOP normal and glaucomatous damage present = H40.1211 (normal-tension/low-tension glaucoma)
    • Review IOP documentation across multiple visits
    • Normal-tension glaucoma is subset requiring different code
  8. Billing bilateral procedures with wrong laterality code:
    • Billing 92083-50 (bilateral visual fields) but only coding H40.1111 (right eye only)
    • If testing both eyes, ensure diagnosis codes support bilateral testing
    • Either code both eyes separately or use bilateral diagnosis code
    • Laterality on procedure codes must match diagnosis codes
  9. Not linking diagnosis to all related testing:
    • Billing OCT (92133) or visual fields (92083) without linking to glaucoma diagnosis
    • All glaucoma monitoring must be linked to H40.1111
    • Not just “abnormal findings” - specific glaucoma diagnosis required
    • Medical necessity demonstrated by diagnosis code
  10. Coding glaucoma suspect as glaucoma:
    • Using H40.1111 when patient only has suspicious findings without confirmed VF loss
    • If suspicious optic nerve but normal visual fields = H40.00-, H40.01-, or H40.02- (glaucoma suspect)
    • Cannot code glaucoma (H40.11-) until visual field defects confirmed
    • Requires reproducible VF loss for glaucoma diagnosis
  11. Overcoding testing frequency without documentation:
    • Billing visual fields or OCT more frequently than annually without justifying medical necessity
    • Must document reason for frequent testing:
      • Newly diagnosed (establishing baseline)
      • Suspected progression
      • Treatment change
      • Rapid disease progression
      • High-risk patient
    • Payers may deny frequent testing without clear documentation
  12. Not documenting angle status:
    • Coding H40.1111 (open-angle glaucoma) without gonioscopy documentation confirming open angle
    • Open angle MUST be documented for open-angle glaucoma codes
    • If angle not documented, query physician before coding
    • Gonioscopy essential for accurate diagnosis and coding
  13. Using unspecified codes when specifics available:
    • Using H40.1110 (stage unspecified) when visual field results documented
    • Using H40.10X0 (unspecified OAG) when primary OAG documented
    • Always code to highest specificity available in documentation
    • Query if information available but unclear
  14. Incorrect modifier use:
    • Not using bilateral modifier (-50) or RT/LT when appropriate for procedures
    • Billing 92083 twice without modifiers when bilateral testing
    • Confusion between professional component (-26) and technical component (-TC)
    • Review payer requirements for modifier usage

Best Practices:

Documentation Review:

  • Confirm ALL three criteria met:
    1. Open angle on gonioscopy
    2. Glaucomatous optic nerve damage
    3. Corresponding visual field defects
  • Verify stage based on current VF pattern using ICD-10 criteria
  • Check for secondary causes (pseudoexfoliation, pigment, trauma, drugs)
  • Verify laterality clearly documented
  • Review IOP trends (if consistently normal, consider H40.12- code)

Coding:

  • Use most specific code available (include stage when documented)
  • Update codes when disease progresses (mild → moderate → severe)
  • Code each eye separately if bilateral with asymmetric stages
  • Link all testing to glaucoma diagnosis for medical necessity
  • Ensure laterality on diagnosis matches procedure laterality

Billing:

  • Document medical necessity for testing frequency
  • Justify more frequent monitoring if progressing or unstable
  • Prior authorization when required (surgery, frequent testing)
  • Coordinate medication coverage with diagnosis
  • Review payer-specific guidelines

Medical Necessity Documentation:

  • Baseline testing upon diagnosis (VF, OCT, photos, pachymetry)
  • Serial monitoring (every 6-12 months if stable, more frequent if progressing)
  • Treatment response assessment (IOP checks 4-6 weeks after medication change)
  • Progression evaluation (comparison to prior testing)
  • Pre-operative evaluation if surgery considered

Quality Metrics:

  • IOP control documented (target IOP, actual IOP, percentage reduction)
  • Disease stability vs progression documented with serial testing
  • Medication adherence addressed
  • Patient education documented
  • Follow-up plan clear (timing, testing planned)

Summary

H40.1111 (Primary Open-Angle Glaucoma, Right Eye, Mild Stage) Key Points:

Clinical:

  • Most common form of glaucoma worldwide
  • Chronic, progressive optic neuropathy with irreversible damage
  • Trabecular meshwork dysfunction → increased IOP → optic nerve damage → ganglion cell death → visual field loss
  • Asymptomatic in mild stage (no patient awareness)
  • Requires comprehensive workup: IOP, gonioscopy, optic nerve exam, OCT, visual fields, pachymetry

Diagnostic Criteria (ALL Required):

  1. Open anterior chamber angle (gonioscopy)
  2. Glaucomatous optic neuropathy (increased C/D, rim loss, RNFL defects)
  3. Corresponding visual field defects (reproducible glaucomatous pattern)
  4. Primary (no secondary cause)

ICD-10 Mild Stage Criteria:

  • Visual field abnormalities present
  • Neither superior NOR inferior hemifield completely involved
  • Central 5 degrees of fixation NOT involved
  • Approximately corresponds to MD better than -6 dB (but ICD-10 based on topographic pattern, not global index)

Coding:

  • H40.1111 = Primary OAG, RIGHT eye, MILD stage
  • Must specify stage (mild, moderate, severe, indeterminate, or unspecified)
  • Must specify laterality (right, left, bilateral, or unspecified)
  • Update code when disease progresses to different stage
  • Code each eye separately if bilateral with asymmetric stages
  • Use different code if secondary cause identified (pseudoexfoliation, pigment, trauma, drugs)

Treatment:

  • Goal: Lower IOP to slow/halt progression (only proven treatment)
  • Target IOP: Individualized; typically 20-30% reduction from baseline or <18 mmHg for mild
  • First-line: Prostaglandin analog eye drops (latanoprost, travoprost, bimatoprost)
  • Additional: Beta-blockers, alpha-agonists, carbonic anhydrase inhibitors, rho kinase inhibitors
  • Laser: Selective laser trabeculoplasty (SLT) as primary or adjunct
  • Surgery: Trabeculectomy, tube shunt, MIGS (usually reserved for advanced disease or medication failure)

Monitoring:

  • Visual fields every 6-12 months
  • OCT every 6-12 months
  • Optic nerve examination each visit
  • IOP each visit
  • More frequent if unstable, progressing, or newly diagnosed

Prognosis:

  • Excellent with appropriate treatment and monitoring
  • Goal: Prevent progression to moderate/severe stages
  • Preserve functional vision for patient’s lifetime
  • Requires lifelong treatment and monitoring
  • Patient adherence critical

HCC: Does NOT map to HCC

Documentation: Must document open angle (gonioscopy), optic nerve damage (C/D, rim assessment, RNFL), visual field defects (pattern, extent, reliability), stage per ICD-10 criteria, and laterality

This completes the comprehensive documentation for ICD-10-CM code H40.1111 (Primary Open-Angle Glaucoma, Right Eye, Mild Stage).

Graph View

Recent Notes