trabeculitis

DEFINITION of trabeculitis

Trabeculitis refers to an inflammatory process affecting the trabecular meshwork, a porous, sponge-like tissue located in the anterior chamber angle of the eye that facilitates the outflow of aqueous humor from the eye into the bloodstream via Schlemm’s canal. This inflammation can impair drainage, resulting in increased intraocular pressure (IOP), which may progress to secondary open-angle glaucoma if untreated. It is commonly associated with infectious or inflammatory conditions, such as viral infections (e.g., herpes simplex or varicella-zoster virus), uveitis, or trauma.

Key features and pathophysiology include:

• Mechanism: Inflammation causes edema, thickening of trabecular beams, accumulation of inflammatory cells (e.g., lymphocytes, macrophages), or keratic precipitates on the meshwork, obstructing aqueous outflow. This can be acute or chronic, often presenting with symptoms like eye pain, redness, blurred vision, halos around lights, or photophobia.
• Etiologies: Frequently viral (herpetic trabeculitis), but can also stem from bacterial infections, tuberculosis, syphilis, trauma (e.g., angle recession), or autoimmune uveitis. In herpetic cases, viral replication in the trabecular endothelium triggers an immune response.
• Diagnosis: Confirmed via gonioscopy (visualizing keratic precipitates or angle abnormalities), slit-lamp examination, tonometry (measuring IOP), and sometimes anterior segment optical coherence tomography (OCT). Laboratory tests may include PCR for viral DNA or serology for underlying infections.
• Complications: Untreated, it can lead to chronic glaucoma, optic nerve damage, visual field loss, or synechiae formation (adhesions in the angle).
• Treatment: Depends on the cause; includes topical corticosteroids to reduce inflammation, antiviral agents (e.g., acyclovir for herpetic cases), IOP-lowering medications (e.g., beta-blockers, prostaglandin analogs), or surgical interventions like trabeculectomy in refractory cases. Prognosis is good with early intervention, but recurrent episodes can cause permanent damage.
• Epidemiology: Rare as a primary condition; more common in association with anterior uveitis (affecting 5-20% of uveitis cases with glaucoma). It typically affects adults, with higher incidence in those with immunocompromise or prior ocular herpes. This condition underscores the link between ocular inflammation and glaucoma, requiring multidisciplinary management by ophthalmologists.

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ETYMOLOGY of trabeculitis

latin - Trabeculitis: Derived from Latin “trabecula” (diminutive of “trabs,” meaning “beam” or “timber”), referring to the beam-like or lattice structure of the trabecular meshwork, which resembles small supporting beams. The suffix “-itis” comes from Greek “-îtis,” indicating “inflammation.” Thus, “trabeculitis” literally means “inflammation of the small beams” (in the context of the eye’s drainage system).

• The term emerged in medical literature in the mid-20th century with advances in gonioscopy and understanding of glaucoma pathophysiology, though “trabecular” structures were described as early as the 19th century by anatomists like Friedrich Schlemm (note: etymology of “ophthalmology” indirectly relates, but specific to trabecula).

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Related Terms

• Anatomical terms: Trabecular meshwork, Schlemm’s canal, anterior chamber angle, aqueous humor, ciliary body
• Associated conditions: Uveitis (anterior, intermediate), iridocyclitis, secondary open-angle glaucoma, ocular hypertension, keratic precipitates (KPs), posterior synechiae.
• Etiologic terms: Herpetic keratitis, herpes simplex virus (HSV), varicella-zoster virus (VZV), traumatic glaucoma, Posner-Schlossman syndrome (glaucomatocyclitic crisis, which may involve trabeculitis-like mechanisms).
• Diagnostic terms: Gonioscopy, tonometry, anterior segment OCT, specular microscopy.
• Treatment-related: Trabeculectomy, laser trabeculoplasty, cyclophotocoagulation, anti-VEGF therapy (if neovascular).
• Similar conditions: Pigmentary glaucoma (pigment dispersion in meshwork), pseudoexfoliation syndrome (material deposition), angle-closure glaucoma (distinct mechanism but related IOP elevation)

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CODING NUANCES

ICD-10-CM Diagnosis Codes:

• H40.40X0 Glaucoma secondary to eye inflammation, unspecified eye, stage unspecified
• H40.41X0 Glaucoma secondary to eye inflammation, right eye, stage unspecified
• H40.42X0 Glaucoma secondary to eye inflammation, left eye, stage unspecified
• H40.43X0 Glaucoma secondary to eye inflammation, bilateral, stage unspecified
• H20.9 Unspecified iridocyclitis|Use for uveitis-related trabeculitis
• H40.1- Open-angle glaucoma; If leading to glaucoma
• H40.89 Other specified glaucoma; For trabeculitis-induced IOP rise
• B25.9 Cytomegaloviral disease NOS; |If CMV-associated
• H58.8 Specified disorders of eye; When none above align

CPT® Procedure Codes:

• 92020 Gonioscopy
• 65800 Paracentesis of anterior chamber
• 65855 Laser trabeculoplasty
• 65820 Goniotomy
• 66170 Trabeculectomy, initial surgery
• 66172 Trabeculectomy with prior scarring
• 66174 Canaloplasty
• 66989 Implantation of aqueous drainage device, internal approach (MIGS)
• 66991 Implantation of aqueous drainage device with cataract surgery

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DERIVATIONS of trabeculitis

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Med roots Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms