H34.211

🧬 ICD-10-CM H34.211 - Partial Retinal Artery Occlusion, Right Eye

📎 Companion Note: See H34.212 for the complete left eye version of this code, including full pathophysiology, embolus classification tables, and systemic workup protocols. This note is laterality-adapted for the right eye with all right-specific code references, etiology codes, and clinical distinctions updated throughout.

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📋 Code Identity

Field	Detail
ICD-10-CM Code	H34.211
Full Descriptor	Partial Retinal Artery Occlusion, Right Eye
Includes (per Tabular)	Hollenhorst’s plaque; Retinal microembolism
Code Type	ICD-10-CM Diagnosis (Billable)
Effective Date	FY 2026 (October 1, 2025 - September 30, 2026)
Chapter	7 - Diseases of the Eye and Adnexa (H00-H59)
Block	H30-H36 - Disorders of Choroid and Retina
Parent Category	H34 - Retinal Vascular Occlusions
Subcategory	H34.21 - Partial Retinal Artery Occlusion
Laterality	6th character = 1 (Right Eye)
Billable?	✅ Yes — 6 characters, fully specified
Chronic vs. Acute	Acute/subacute — embolic/ischemic vascular event
Urgent Referral Indicated?	✅ Yes — cardiovascular/neurovascular workup urgently indicated
CC/MCC Status	Non-CC / Non-MCC
Excludes 1	Amaurosis fugax G45.3 — cannot be coded simultaneously
CMS LCD Coverage	✅ Explicitly listed in CMS A57600 Posterior Segment Imaging LCD

⚠️ Laterality: ICD-10-CM H34.211 is right eye only. Use H34.212 for the left eye, H34.213 for bilateral, and H34.219 for unspecified eye. Never assign unspecified when laterality is documented.

🔴 Excludes 1 — Absolute Rule: G45.3 (Amaurosis fugax) and H34.211 are mutually exclusive in ICD-10-CM. If the patient reports transient right monocular visual loss but no plaque is confirmed on fundoscopy → G45.3. If a Hollenhorst plaque or microembolism is confirmed on fundoscopic exam, even in an asymptomatic patient → H34.211. You cannot assign both on the same claim — this is a hard Excludes 1 edit.

🚨 MEDICAL URGENCY: A partial retinal artery occlusion — especially with a confirmed Hollenhorst plaque — is a systemic thromboembolic emergency. It signals active embolic disease, most commonly from the ipsilateral right carotid artery or cardiac sources. AHA and AAO guidelines both mandate urgent neurological and cardiovascular evaluation. As a coder, this encounter is also a prime opportunity to capture the HCC-generating upstream comorbidities that are frequently first identified or documented here.

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🔬 Clinical Description

Partial retinal artery occlusion (PRAO), right eye represents an incomplete obstruction of the right central retinal artery (CRA) or one of its branches, where arterial blood flow is significantly reduced but not fully interrupted. The pathological hallmark is either a visible embolic plaque (most commonly a bright, refractile Hollenhorst cholesterol crystal) lodged at an arterial bifurcation, or a retinal microembolism detectable on fluorescein angiography as focal delayed filling. Unlike complete branch retinal artery occlusion (BRAO) H34.231 where an entire arterial segment is occluded, or complete central retinal artery occlusion (CRAO) H34.11 where all retinal perfusion is lost, a partial RAO implies residual, reduced flow past the point of obstruction.

The Hollenhorst Plaque — Right Eye Clinical Significance

The ICD-10-CM Tabular List explicitly includes “Hollenhorst’s plaque” and “retinal microembolism” in the H34.21x subcategory. Named after ophthalmologist Robert W. Hollenhorst (1961), Hollenhorst plaques are cholesterol microemboli — bright, shiny, yellow-orange crystalline deposits visible at retinal arterial bifurcations. For the right eye, the most common embolic source is the right internal carotid artery and its atheromatous plaques — making H34.211 a direct indicator of right carotid artery disease requiring urgent duplex ultrasound evaluation.

Key right-eye-specific anatomical pathway for embolus transit:

• Right common carotid artery → right internal carotid artery → right ophthalmic artery → right central retinal artery → right retinal arterial bifurcations (where emboli lodge)

🎯 Right vs. Left Laterality Matters Clinically: A right eye Hollenhorst plaque should trigger evaluation of the right carotid artery specifically (I65.21). Do not confuse laterality when coding the carotid stenosis — right eye plaque + right carotid stenosis = I65.21, not I65.22. This is a frequent error when the laterality of the carotid code is not carefully matched to the eye.

Embolus Type Reference

Embolus Type	Fundus Appearance	Most Common Origin	Occlusion Pattern
Cholesterol (Hollenhorst)	Bright, yellow-orange, refractile, glistening	Right carotid atheroma, aortic arch	Partial — smaller than lumen; wedges at bifurcation
Calcific	White, dull, non-refractile, opaque	Cardiac valves (aortic stenosis), calcified carotid plaque	Often complete or near-complete; larger fragment
Fibrin-platelet	Gray, dull, elongated, non-refractile	Cardiac (A-fib, endocarditis, mural thrombus), arterial thrombus	Variable; may fragment and migrate spontaneously
Septic	Variable; associated retinal white infiltrate	Infectious endocarditis	Rare; requires blood cultures and infectious workup

Pathophysiologic Sequence

1. Plaque rupture / embolus release — Atheromatous plaque in the right internal carotid artery (or cardiac source) ruptures, releasing cholesterol crystals, fibrin-platelet aggregates, or calcific material into the circulation.
2. Arterial transit — Embolus travels: right common carotid → right internal carotid → right ophthalmic artery → right CRA → retinal arterial bifurcation where it lodges due to vessel narrowing at the bifurcation point.
3. Partial luminal obstruction — The embolus (particularly cholesterol crystals, which are often smaller than the arterial lumen) reduces but does not completely eliminate blood flow → partial ischemia downstream.
4. Variable retinal ischemia — Degree of ischemic injury depends on duration and degree of flow reduction. Minor partial occlusion = no visible retinal change. Significant partial occlusion = sector retinal whitening (opacification of ischemic inner retinal layers).
5. Embolus behavior — Cholesterol emboli may remain permanently lodged at the bifurcation (visible indefinitely on fundoscopy) or fragment and migrate distally, potentially producing symptom fluctuation.
6. Chronic consequences — Long-standing partial ischemia may produce: inner retinal atrophy (RNFL/GCC thinning on OCT), visual field defects, and rarely retinal neovascularization from ischemia-driven VEGF upregulation.

Visual Impact by Degree of Occlusion

Degree	Visual Symptoms	Fundoscopic Findings
Minimal (small cholesterol embolus, high-flow vessel)	Asymptomatic or brief transient blur	Refractile plaque visible at bifurcation; no retinal whitening
Moderate (significant flow reduction)	Sector visual field defect; mild acuity reduction; photopsia	Sector retinal whitening downstream; plaque visible at obstruction site
Severe partial (near-complete, flow barely maintained)	Dense sectoral VF loss; significant acuity reduction mimicking BRAO	Diffuse sector opacification; box-carring of arterial column; RAPD possible
Fluctuating (migrating embolus)	Recurrent transient monocular visual loss; variable symptoms	Embolus visible at different bifurcation points on serial exams

Diagnostic Imaging — Right Eye

Modality	Acute/Active Findings	Chronic/Resolved
Fundus Photography	Bright refractile yellow-orange plaque at right arterial bifurcation; segmental retinal whitening; box-carring of right arterial blood column	Persistent plaque; retinal whitening resolves over weeks; inner retinal atrophy in ischemic sector
Fluorescein Angiography (FA)	Delayed arterial filling distal to right plaque; focal hypofluorescence at occlusion site; NPR zone; slowed arteriovenous transit time	Restored flow if embolus migrated; arterial wall staining at prior plaque site
OCT Posterior Segment	Hyperreflective thickening of inner retinal layers (ischemic edema) in affected right eye sector; disc edema if pre-laminar	Inner retinal atrophy; GCC/RNFL thinning in right eye ischemic zone; macular thinning
OCTA	Loss of superficial and deep capillary plexus flow in ischemic right eye sector; plaque as flow void in arterial tree	Persistent right eye capillary non-perfusion; possible collateral formation
OCT Optic Nerve	Acute RNFL edema if CRA partially involved	RNFL thinning in right eye affected sector chronically

Urgent Systemic Workup Protocol

Workup Element	Right-Eye-Specific Consideration	Timeframe
Right carotid artery duplex ultrasound	Right ICA is the primary embolic source for right eye findings → code I65.21 when stenosis confirmed	Same day or within 24 hours
Cardiac evaluation / 12-lead ECG	Identify A-fib, valvular disease, cardiac thrombus as alternative cardioembolic source	Urgent
TTE or TEE echocardiogram	PFO, valvular disease, intracardiac thrombus, paradoxical embolism	Within 24-48 hours
MRI brain with DWI	Rule out concurrent right MCA or posterior circulation ischemic stroke; right eye symptoms → right hemisphere territory risk	Same day / urgent ED referral if neurological symptoms
Fasting lipid panel / CRP	Atherosclerotic risk stratification	Urgent outpatient labs
CBC, coagulation / hypercoagulable panel	Thrombocytosis, antiphospholipid syndrome, hyperviscosity	Urgent
Blood pressure measurement	Hypertension drives atherosclerosis progression	Immediate
HbA1c / fasting glucose	Diabetes as vascular risk factor	Urgent
ESR / CRP	Giant cell arteritis in patients ≥ 50 years — GCA can cause RAO	Urgent in appropriate age group; consider temporal artery biopsy

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🌳 Code Tree

H34 - Retinal Vascular Occlusions
│
├── H34.0 - Transient Retinal Artery Occlusion
│   ├── H34.01 - Right eye
│   ├── H34.02 - Left eye
│   ├── H34.03 - Bilateral
│   └── H34.09 - Unspecified eye
│
├── H34.1 - Central Retinal Artery Occlusion (CRAO) — Complete
│   ├── H34.10 - Unspecified eye
│   ├── H34.11 - Right eye
│   ├── H34.12 - Left eye
│   └── H34.13 - Bilateral
│
├── H34.2 - Other Retinal Artery Occlusions
│   │
│   ├── H34.21 - Partial Retinal Artery Occlusion
│   │   *(Includes: Hollenhorst's plaque; Retinal microembolism)*
│   │   ├── H34.211 - Right eye  ◀ THIS CODE
│   │   ├── H34.212 - Left eye
│   │   ├── H34.213 - Bilateral
│   │   └── H34.219 - Unspecified eye
│   │
│   ├── H34.23 - Retinal Artery Branch Occlusion (BRAO) — Complete
│   │   *(More severe — complete branch occlusion)*
│   │   ├── H34.231 - Right eye
│   │   ├── H34.232 - Left eye
│   │   ├── H34.233 - Bilateral
│   │   └── H34.239 - Unspecified eye
│   │
│   └── H34.29 - Other Retinal Artery Occlusions
│       ├── H34.291 - Right eye
│       ├── H34.292 - Left eye
│       ├── H34.293 - Bilateral
│       └── H34.299 - Unspecified eye
│
├── H34.8 - Other Retinal Vascular Occlusions
│   ├── H34.81 - Central Retinal Vein Occlusion (CRVO)
│   │   ├── H34.8110 - Right eye, with macular edema
│   │   ├── H34.8111 - Right eye, stable
│   │   └── ...
│   ├── H34.82 - Venous engorgement (NOS)
│   └── H34.83 - Tributary (Branch) Retinal Vein Occlusion
│       └── ...
│
└── [[H34.9]] - Unspecified retinal vascular occlusion

🔍 H34.211 vs. H34.231 vs. H34.11 — Right Eye Severity Spectrum:

Code	Description	Occlusion Degree	Typical Vision Loss	Embolus Size
H34.211	Partial RAO, right eye	Incomplete — flow reduced, not absent	Variable; mild to moderate or none	Small; often cholesterol crystal
H34.231	Branch RAO (BRAO), right eye	Complete occlusion of a branch artery	Sectoral VF loss; permanent if untreated	Larger; calcific or fibrin-platelet
H34.11	Central RAO (CRAO), right eye	Complete CRA occlusion	Sudden, profound, often near-total	Large thrombus or embolus; cardioembolic
H34.01	Transient RAO, right eye	Temporary — full resolution, no plaque	Transient monocular visual loss	Microembolus that migrates; or vasospasm

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✅ Includes

H34.211 explicitly captures the following per ICD-10-CM Tabular:

• Hollenhorst’s plaque, right eye — cholesterol crystal microembolus visible at a right retinal arterial bifurcation; symptomatic or incidental finding on routine dilated exam
• Retinal microembolism, right eye — any microscopic embolic material (cholesterol, fibrin-platelet, calcific, septic) causing partial occlusion of a right retinal artery, confirmed clinically or angiographically
• Partial occlusion of the central retinal artery, right eye — significant right CRA flow reduction without complete cessation of perfusion
• Partial occlusion of a right retinal arterial branch — incomplete branch obstruction where some flow is maintained distally
• Incidentally discovered cholesterol plaque, right eye — found on routine exam with no acute symptoms; always coded as H34.211 per the Tabular Includes instruction

🔍 Never Skip the Incidental Plaque: Documentation reading “incidental bright refractile plaque noted at the right superior temporal arterial bifurcation — patient asymptomatic” is H34.211. Asymptomatic Hollenhorst plaques carry major systemic significance (right carotid atheroembolism) and directly support medical necessity for urgent carotid imaging and vascular referral.

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🚫 Excludes

Excludes 1 (Mutually Exclusive — CANNOT be coded together)

Excluded Code	Description	Clinical Decision Rule
G45.3	Amaurosis fugax	Right eye transient visual loss, fully resolved, NO plaque on fundoscopy → G45.3; Hollenhorst plaque confirmed on right eye fundoscopy → H34.211; never assign both

Excludes 1 Right-Eye Decision Tree

Patient: right eye transient or persistent visual change
         ↓
Dilated fundus exam performed
         ↓
Is a Hollenhorst plaque / retinal microembolism
visible on right eye fundoscopy?
         │
    YES  │  NO
         │
  H34.211    Did symptoms fully resolve
  (Partial RAO,  with no structural finding?
   right eye)         │
                 YES  │  NO
                      │
               G45.3   Is there segmental
               (Amaurosis   retinal whitening /
                fugax)      arterial attenuation
                            suggesting complete
                            branch occlusion?
                                   │
                             YES   │
                            H34.231 (BRAO)

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🏥 HCC (Hierarchical Condition Category)

Field	Detail
HCC Mapped?	❌ No — H34.211 does not directly map to CMS-HCC v28
RAF Score Contribution	None from this code alone
Risk Adjustment Clinical Relevance	Very High — through HCC-rich associated cardiovascular and cerebrovascular comorbidities

💰 RAF Strategy — Right Eye PRAO Is a Sentinel HCC Event: While H34.211 carries no direct RAF weight, it reliably co-occurs with heavily weighted HCC conditions. The encounter triggered by a right eye Hollenhorst plaque is one of the most impactful HCC documentation opportunities in an ophthalmology practice. Systematically review and code every confirmed systemic comorbidity:

Code	Description	HCC?	Right-Eye Relevance
I65.21	Occlusion and stenosis of right carotid artery	✅ HCC 108	Primary embolic source for right eye Hollenhorst plaque; ipsilateral right ICA
I65.22	Occlusion and stenosis of left carotid artery	✅ HCC 108	If bilateral carotid disease identified
I48.91	Unspecified atrial fibrillation	✅ HCC 96	Cardioembolic source; high-risk fibrin-platelet embolus
I48.19	Persistent atrial fibrillation, unspecified	✅ HCC 96	More specific A-fib documentation
I48.11	Longstanding persistent A-fib	✅ HCC 96	Highest AF stroke risk category
I25.10	Atherosclerotic heart disease, native CA	✅ HCC 88	Systemic atherosclerosis; common in Hollenhorst plaque patients
I63.512	Cerebral infarction, left MCA (contralateral to right eye)	✅ HCC 100	Right ICA embolus → left hemisphere stroke possible
I63.311	Cerebral infarction due to thrombosis, right MCA	✅ HCC 100	Concurrent right MCA territory stroke
E11.9	Type 2 DM without complications	✅ HCC 19	Major cardiovascular risk factor
E11.65	T2DM with hyperglycemia	✅ HCC 19	More specific
I10	Essential hypertension	❌ None	Ubiquitous comorbidity; always code when documented
E78.5	Hyperlipidemia, unspecified	❌ None	Atherogenic risk factor
Z82.49	Family history of ischemic heart disease	❌ None	Risk context; supports workup documentation

🎯 Right-Laterality Stroke Risk Note: A right eye Hollenhorst plaque from right ICA disease poses risk for ipsilateral right MCA territory ischemia (left hemisphere) — manifesting as left-sided weakness, aphasia (if dominant hemisphere). Right hemisphere embolism → left-sided symptoms. Ensure MRI DWI/ADC maps the right hemisphere in the acute workup and code any confirmed infarct.

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🏨 MS-DRG (Medicare Severity DRG)

Field	Detail
CC/MCC Status	⬜ Non-CC / Non-MCC — CMS MS-DRG v42
Primary MS-DRG (as PDx)	MS-DRG 124 - Other Disorders of the Eye with MCC
Primary MS-DRG (as PDx, no CC/MCC)	MS-DRG 125 - Other Disorders of the Eye without MCC/CC
MDC	MDC 02 - Diseases and Disorders of the Eye
Inpatient Admission Likelihood	Moderate — PRAO alone is typically outpatient; inpatient more likely when concurrent stroke, TIA, or new A-fib is identified during workup
CMS MS-DRG Version	v42 (FY2026)

🏥 Inpatient DRG Sequencing — Concurrent Neurological Event: When a patient with H34.211 is admitted and neuroimaging reveals a concurrent ischemic stroke, the stroke code (e.g., I63.311 or I63.512 depending on territory) becomes the principal diagnosis. The MS-DRG assignment shifts entirely to MDC 01 (Diseases of the Nervous System), where stroke codes carry MCC/CC weight. H34.211 becomes a secondary diagnosis and its Non-CC status does not affect the DRG. In this scenario, accurate stroke coding entirely determines the DRG value — making it critical that the ophthalmology consult note clearly documents the right eye Hollenhorst plaque for the shared record.

🏥 Common Inpatient Secondary Diagnosis Contexts for H34.211:

• Right carotid endarterectomy (CEA) admission — Hollenhorst plaque prompted carotid workup; CEA performed
• Cardiac ablation for A-fib — Workup of right eye embolus identified A-fib; admitted for ablation
• TIA/Stroke admission — Right eye plaque discovered on bedside ophthalmology consult during stroke workup
• Cardiac catheterization admission — Systemic atherosclerosis workup

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💊 Associated CPT Codes (Commonly Reported With H34.211)

wRVU values reflect 2025 CMS Medicare Physician Fee Schedule Final Rule.

Ophthalmology CPT Codes

CPT Code	Description	wRVU (Non-Fac)	wRVU (Facility)	Assistant Payable?	Relevance
92235	Fluorescein angiography with interpretation and report	0.92	0.92	No	Essential — confirms right eye arterial obstruction, filling delay, NPR zone; CMS LCD covered for H34.211
92134	OCT posterior segment with interpretation and report	0.00	0.00	No	Documents right eye ischemic inner retinal thickening acutely; GCC/RNFL atrophy chronically
92137	OCT with OCT angiography (OCTA)	0.79	0.79	No	Maps right eye capillary non-perfusion; NV monitoring; cannot bill same day as 92134
92133	OCT optic nerve with interpretation and report	0.00	0.00	No	Right eye RNFL thinning; cannot bill same day as 92137
92250	Fundus photography with interpretation and report	0.00	0.00	No	Documents plaque location, retinal whitening; baseline right eye documentation
99215	E/M, established patient, high complexity	2.85	2.85	No	Acute finding; urgent coordination; high MDM
99205	E/M, new patient, high complexity	3.50	3.50	No	New diagnosis of right eye partial RAO
99254	Inpatient consultation, moderate-high complexity	5.30	5.30	No	Inpatient ophthalmology consult during stroke/TIA admission
99255	Inpatient consultation, high complexity	6.71	6.71	No	Complex bedside consult with multiple comorbidities and urgent decision-making

CMS LCD Confirmation

✅ H34.211 is explicitly listed in the CMS Billing and Coding article for Scanning Computerized Ophthalmic Diagnostic Imaging (A57600 v34), confirming 92134 and 92137 are covered for this diagnosis. It is also covered for 92235 FA under the CMS Ophthalmic Angiography LCD (A56774 v22).

Associated Non-Ophthalmology Workup CPTs (Multidisciplinary Context)

CPT Code	Description	Billing Specialty	Right-Eye Relevance
93880	Duplex scan of extracranial arteries, bilateral	Vascular / Radiology	Right carotid duplex — primary right eye embolic source workup
93882	Duplex scan of extracranial arteries, unilateral	Vascular / Radiology	Unilateral right carotid study when bilateral not indicated
93306	Echocardiography, transthoracic, complete	Cardiology	Cardiac embolic source evaluation
93312	Echocardiography, transesophageal	Cardiology	TEE for PFO, valvular disease, intracardiac thrombus
70553	MRI brain with contrast	Radiology	Rule out concurrent right MCA ischemic stroke
70557	MRI brain + MRA without contrast	Radiology	Combined brain + cerebrovascular workup
93000	Electrocardiogram, routine	Cardiology / PCP	Rule out A-fib as cardioembolic source

⚠️ Key NCCI / Billing Rules

• 92137 (OCTA) cannot be billed same day as 92134 (OCT posterior segment) or 92133 (OCT optic nerve) — NCCI edit; mutually exclusive same DOS
• 92235 (FA) is CMS LCD-covered for H34.211 — documented in both A56774 (FA) and A57600 (SCODI/OCT) LCD articles
• Modifier -25 required when E/M + imaging (FA, OCT) billed on the same DOS
• 99205 (new patient) requires the 3-year rule — if this patient has not been seen by this provider or any provider of the same specialty within the same group within 3 years, new patient status applies
• High-complexity MDM for 99215/99205 is almost always justifiable: new/acute problem with uncertain prognosis, independent data interpretation (FA, OCT), plus coordination of care with vascular surgery/neurology/cardiology

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🔧 Applicable Modifiers

Modifier	Description	Application with H34.211
-RT	Right side	Append to all CPT codes for the right eye (e.g., 92235-RT, 92134-RT)
-LT	Left side	When fellow left eye also examined or imaged at same encounter
-50	Bilateral procedure	Bilateral imaging (FA, OCT) same session
-25	Significant, separately identifiable E/M same day as procedure	Required when E/M + 92235, 92134, or 92137 on same DOS; document E/M independently
-59	Distinct procedural service	Two distinct procedures separately documented; breaks NCCI edits when appropriate
-26	Professional component	Physician interprets imaging performed at another facility
-TC	Technical component	Facility technical imaging billing only
-GC	Service by resident under supervision	Teaching/academic hospital setting
-GA	ABN on file	Medicare ABN obtained for potentially non-covered service
-AI	Principal physician of record	When ophthalmologist assumes principal physician role inpatient
-57	Decision for surgery	E/M on same day as 90-day global surgical decision; verify global period for any planned procedure

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📝 Coding Examples

Example 1 — Incidental Right Eye Hollenhorst Plaque on Routine Annual Exam

A 65-year-old established male presents for routine annual dilated fundus exam. No visual complaints. On dilated exam: a bright, refractile, yellow-orange Hollenhorst plaque is noted at the right superior temporal arterial bifurcation. No retinal whitening; no RAPD. Left eye unremarkable. OCT right eye: no inner retinal thickening or atrophy. FA right eye: focal delayed filling at the plaque site; no NPR beyond the immediate embolus. Patient urgently referred to PCP for right carotid duplex and cardiac workup. History: hypertension, hyperlipidemia, former smoker.

Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (Hollenhorst plaque; incidental)
• I10 - Essential hypertension
• E78.5 - Hyperlipidemia, unspecified
• F17.210 - Nicotine dependence, cigarettes, uncomplicated (or Z87.891 for former smoker status)

CPT Codes:

• 99215 - -25 - E/M, established patient, high complexity (acute new finding with uncertain prognosis; urgent care coordination; independent data interpretation)
• 92235 - -RT - Fluorescein angiography, right eye
• 92134 - -50 - OCT posterior segment, bilateral (right eye primary; left eye baseline)
• 92250 - -50 - Fundus photography, bilateral (documents plaque location and appearance)

💡 MDM Documentation Tip: Under the 2021+ AMA E/M guidelines, this visit qualifies for high complexity because: (1) new problem with uncertain prognosis (Hollenhorst plaque = unknown carotid/cardiac status), (2) independent interpretation of FA and OCT, (3) independent coordination of care with PCP + vascular surgery referral. Document all three explicitly in your MDM section.

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Example 2 — New Patient, Transient Right Eye Visual Blur, Plaque Confirmed

A 70-year-old male, new patient, referred from his PCP after reporting sudden painless right eye “black shade” lasting approximately 15 minutes, which then resolved. Dilated fundus exam: bright cholesterol plaque visible at the right inferior temporal arterial bifurcation. Mild segmental retinal pallor inferior temporally, right eye — consistent with partial ischemia during the symptomatic event. OCT right eye: mild inner retinal hyperreflectivity inferior temporally. FA right eye: delayed filling in the right inferior temporal arteriole at the plaque site. BP today: 178/98. No RAPD.

Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (plaque confirmed → H34.211 takes priority over G45.3 per Excludes 1)
• I10 - Essential hypertension (BP 178/98)
• E78.5 - Hyperlipidemia (if documented in history)

CPT Codes:

• 99205 - -25 - E/M, new patient, high complexity
• 92235 - -RT - FA, right eye
• 92134 - -RT - OCT posterior segment, right eye
• 92250 - -50 - Fundus photography, bilateral

🔴 G45.3 Exclusion Applied: The patient described amaurosis fugax-like symptoms, but the confirmed fundoscopic plaque mandates H34.211 under the Excludes 1 rule. Document clearly: “Hollenhorst plaque visible at right inferior temporal bifurcation — confirmed on fundoscopy and fluorescein angiography.”

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Example 3 — Established Patient, Right Carotid Stenosis Confirmed on Workup

An established 73-year-old female returns after urgent workup prompted by right eye Hollenhorst plaque discovered last visit. Right carotid duplex (vascular surgery): 80% right ICA stenosis confirmed. Cardiac workup: normal sinus rhythm, no cardioembolic source. CEA (right carotid endarterectomy) scheduled by vascular surgery next week. Today: right eye OCT confirms mild inferior temporal GCC thinning (chronic ischemic change). Plaque still visible at same location.

Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (persistent Hollenhorst plaque)
• I65.21 - Occlusion and stenosis of right carotid artery (confirmed on duplex — HCC 108)
• I10 - Essential hypertension

CPT Codes:

• 99215 - -25 - E/M, established patient, high complexity (new carotid stenosis data; surgical coordination; chronic ischemic change on OCT)
• 92134 - -RT - OCT posterior segment, right eye (GCC thinning progression monitoring)
• 92250 - -RT - Fundus photography, right eye (persistent plaque documentation)

💰 HCC 108 Alert: I65.21 (right carotid occlusion/stenosis, confirmed by carotid duplex) maps to HCC 108 — one of the highest-impact vascular HCC codes. When the ophthalmologist reviews the carotid duplex report and documents the confirmed diagnosis of right carotid stenosis in their note, this code can be captured from the ophthalmology encounter. Ensure the documentation includes the basis for the diagnosis (review of duplex results) per CMS guidelines.

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Example 4 — Right Eye PRAO + New Atrial Fibrillation Discovered

A 77-year-old established female presents with a 2-day history of right eye visual disturbance — “like looking through fog” in the superior field. Dilated exam: dull, gray elongated embolus visible at the right superior temporal arterial bifurcation — fibrin-platelet appearance. OCT right eye: inner retinal thickening superiorly. In-office ECG performed: irregularly irregular rhythm — atrial fibrillation confirmed. Patient sent to ED for urgent anticoagulation evaluation.

Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (fibrin-platelet embolus; partial occlusion)
• I48.91 - Unspecified atrial fibrillation (new onset confirmed on in-office ECG — HCC 96)
• I10 - Essential hypertension (if documented)

CPT Codes:

• 99215 - -25 - E/M, established patient, high complexity
• 92134 - -RT - OCT posterior segment, right eye
• 92250 - -RT - Fundus photography, right eye (documents embolus morphology)

🚨 High-Complexity E/M — Extreme Case: This is arguably one of the highest-complexity E/M scenarios in ophthalmology: new diagnosis of A-fib, relationship to retinal embolism confirmed, emergency referral decision made. Document the full scope: independent diagnosis of A-fib on ECG, clinical correlation with retinal embolism, decision for emergency evaluation, and coordination with cardiology/ED.

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Example 5 — Bilateral Hollenhorst Plaques (Right Greater Than Left)

An established 68-year-old male presents for diabetic eye exam. Incidentally, dilated exam reveals Hollenhorst plaques in both eyes — right eye superior temporal and nasal bifurcation (2 plaques) and left eye inferior temporal (1 plaque). Patient has controlled Type 2 diabetes, hypertension, hyperlipidemia. No acute visual symptoms.

Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (multiple right eye plaques)
• H34.212 - Partial retinal artery occlusion, left eye (left eye plaque)
• E11.9 - Type 2 diabetes mellitus without complications (DM; HCC 19; no diabetic retinopathy documented)
• I10 - Essential hypertension
• E78.5 - Hyperlipidemia

💡 Bilateral Coding Note: H34.213 (bilateral) is an option when both eyes have confirmed partial RAO/plaques at the same encounter. However, when the right eye has multiple plaques and the clinical picture is asymmetric, coding H34.211 + H34.212 separately preserves the most granular laterality documentation. Use H34.213 when bilateral disease is equivalent and symmetrically described.

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Example 6 — Inpatient Ophthalmology Consult During Stroke Admission

A 79-year-old male admitted by neurology for acute right MCA ischemic stroke — left-sided weakness and aphasia. Ophthalmology consulted to evaluate for ocular embolic source and fundoscopic changes. Bedside dilated exam: right eye Hollenhorst plaque at superior temporal bifurcation. No retinal whitening currently. Right carotid MRA (from neuroradiology): 85% right ICA stenosis. CEA planned post-stabilization.

Ophthalmology Consult Diagnosis Codes:

• H34.211 - Partial retinal artery occlusion, right eye (right eye Hollenhorst plaque — ophthalmology-documented)
• I65.21 - Occlusion/stenosis, right carotid artery (confirmed on MRA — HCC 108)
• (Neurology codes stroke as PDx separately — e.g., I63.311)

CPT Codes (Ophthalmology Inpatient Consult):

• 99254 - Inpatient consultation, moderate-high complexity
• 92250 - -RT - Portable fundus photography at bedside (documents plaque for the medical record)

🏥 Sequencing Note: H34.211 is a secondary diagnosis in this admission; the stroke drives the PDx and MDC assignment. However, the ophthalmology documentation of the right eye Hollenhorst plaque and its correlation with the confirmed right carotid stenosis is clinically critical for the permanent medical record, surgical planning, and comorbidity documentation.

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🔗 Related Diagnoses to Consider Coding Together

Code	Description	Relationship to H34.211
I65.21	Occlusion and stenosis of right carotid artery	Primary embolic source for right Hollenhorst plaque; HCC 108 — match laterality
I65.22	Occlusion and stenosis of left carotid artery	Bilateral carotid disease; also HCC 108
I48.91	Unspecified atrial fibrillation	Cardioembolic source; HCC 96
I48.11	Longstanding persistent A-fib	More specific A-fib; HCC 96
I25.10	Atherosclerotic heart disease, native CA	Systemic atherosclerosis; HCC 88
I10	Essential hypertension	Major risk factor; mandatory when documented
E78.5	Hyperlipidemia, unspecified	Atherogenic dyslipidemia
E11.9	Type 2 DM without complications	Vascular risk factor; HCC 19
H34.212	Partial RAO, left eye	Contralateral plaque — bilateral disease
H34.213	Partial RAO, bilateral	Use when both eyes equally affected
H34.231	Branch RAO (BRAO), right eye	Progression to complete branch occlusion
H34.11	Central RAO (CRAO), right eye	Most severe progression
H34.01	Transient RAO, right eye	Prior transient episodes without confirmed plaque
H35.051	Retinal NV, unspecified, right eye	Late ischemic NV if NPR develops from chronic partial occlusion
H43.11	Vitreous hemorrhage, right eye	Rare late complication from NV secondary to partial RAO ischemia
G45.3	Amaurosis fugax	Mutually exclusive (Excludes 1) — do NOT code with H34.211
I63.311	Cerebral infarction, right MCA territory	Concurrent right hemisphere ischemic stroke
I63.512	Cerebral infarction, unspecified MCA, left side	Emboli from right ICA → left hemisphere territory
Z82.49	Family history of ischemic heart disease	Risk documentation for cardioembolic workup justification

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⚖️ H34.211 vs. G45.3 — Right Eye Decision Guide

Clinical Scenario	Correct Code	Do NOT Use
Transient right monocular visual loss, fully resolved, no plaque on fundoscopy	G45.3	H34.211
Transient right monocular visual loss, fully resolved, Hollenhorst plaque confirmed	H34.211	G45.3
Asymptomatic patient, right eye Hollenhorst plaque found incidentally	H34.211	Nothing; this is always coded
Right eye VF defect with plaque at right arterial bifurcation; some flow maintained	H34.211	H34.231 (reserve for complete branch occlusion)
Right eye complete sectoral vision loss; complete branch arterial occlusion on FA	H34.231	H34.211
Right eye sudden, profound vision loss; CRA completely occluded on FA	H34.11	H34.211
Bilateral plaques confirmed at same encounter	H34.213 or H34.211 + H34.212	H34.219 (when eyes are lateralized)

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📌 ICD-9-CM Crosswalk

ICD-9-CM	Description
362.33	Arterial occlusion, retinal, partial

📝 ICD-9-CM 362.33 had no laterality. The ICD-10-CM transition added right/left/bilateral specificity — enabling precise correlation of right eye embolic events with right carotid artery disease in outcomes research and population health analytics.

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🧑‍💻 Coder Pearls

1. Every confirmed Hollenhorst plaque = H34.211. Asymptomatic, incidental, transient — it does not matter. A visible cholesterol crystal confirmed on fundoscopy is always coded as partial RAO per the ICD-10-CM Tabular Includes note.
2. Excludes 1 with G45.3 is absolute. No exceptions, no workarounds. Plaque on fundoscopy → H34.211. No plaque → G45.3. Never code both.
3. Right eye = right carotid. When coding the vascular etiology, the right eye embolic pathway flows through the right ICA → I65.21 (not I65.22). Getting the laterality of the carotid code right is essential for clinical accuracy, surgical planning documentation, and HCC validation.
4. I65.21 = HCC 108 — highest-value code in this cluster. Confirmed right carotid stenosis as a carotid duplex-documented finding produces significant RAF. When the ophthalmologist documents the confirmed diagnosis and reviews the carotid imaging data, this code is capturable from the ophthalmology encounter.
5. In-office ECG → I48.91 = HCC 96. When A-fib is discovered as the workup of a right eye embolic event, this is among the highest-value HCC captures possible in an ophthalmology practice. Document the ECG finding, the clinical significance, and the ED referral or cardiology coordination.
6. Concurrent stroke changes the entire coding framework. When MRI reveals a concurrent right MCA stroke, the stroke code sequences first inpatient, shifts MDC to 01, and picks up CC/MCC weight. H34.211 becomes a secondary diagnosis. Accurate sequencing between ophthalmology and neurology documentation is essential.
7. High MDM is almost always justified. New problem with uncertain prognosis (carotid/cardiac status unknown) + independent FA/OCT interpretation + coordination of care with ≥1 external specialty = high complexity MDM under 2021+ AMA guidelines every time.
8. Serial monitoring is billable and necessary. Patients with known Hollenhorst plaques require scheduled follow-up — plaque stability, new plaque formation, VF monitoring, OCT GCC tracking, and NV development surveillance. Document the clinical necessity for each visit.
9. OCTA is the frontier for NV surveillance. If chronic partial ischemia drives retinal NV (H35.051), OCTA (92137) is the most sensitive monitoring tool. Watch the NCCI edit — it cannot be billed same day as 92134 or 92133.
10. This code is a multidisciplinary bridge. H34.211 routinely generates referrals to vascular surgery, neurology, and cardiology. Documenting the care coordination in the ophthalmology note — and ensuring the referred specialists code the confirmed downstream diagnoses — is essential for complete risk adjustment capture across the care team.

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Sources: ICD-10-CM FY2026 Tabular List, CMS.gov; AAPC Codify H34.211 and H34.21 Subcategory; ECGWaves H34.211 Code Reference; FindACode H34.211 (updated Mar 2026); GenHealth H34.211; CMS Billing & Coding: Scanning Computerized Ophthalmic Diagnostic Imaging A57600 v34 (Jan 2025) — H34.211 explicitly listed; CMS Billing & Coding: Ophthalmic Angiography FA/ICG A56774 v22; Ophthalmology Advisor - Retinal Artery Occlusion Signals Warning of Stroke/Heart Attack, Dec 2024; Cleveland Clinic Consult QD - Stroke Risk After Retinal Artery Occlusion, Jul 2025; NIH StatPearls - Hollenhorst Plaque, NCBI Bookshelf; CMS ICD-10-CM/PCS MS-DRG v42 Definitions Manual; ASRS Retina Coding for Beginners, Mar 2024; CMS 2025 Medicare Physician Fee Schedule Final Rule; Review of Ophthalmology - Coding and Reimbursement 2026 Update, Jan 2026