Viral uveitis
Reviewed by Ivan Yip

This review covers viral causes of anterior uveitis. A viral aetiology should be suspected when anterior uveitis is accompanied by ocular hypertension, diffuse stellate keratic precipitates or the presence of iris atrophy. Most common viruses associated are herpes simplex, varicella-zoster virus, cytomegalovirus (CMV) and rubella virus. Diagnostic clues include small and medium sized keratitis precipitates in Arlt’s triangle, with or without corneal scars, suggestive of herpes simplex or varicella zoster virus infection. Secondly, Posner-Schlossman syndrome with few medium sized keratic precipitates, minimal anterior chamber cells and extremely high intraocular pressure; mainly associated with CMV. Thirdly, Fuchs uveitis syndrome, with fine stellate keratic precipitates diffusely distributed over the corneal endothelium which can be associated with rubella or CMV. In rubella, the onset is in the second to third decade presenting with posterior subcapsular cataract, iris heterochromia and vitritis without macula oedema. CMV associated affects mainly Asian males in their fifth to seventh decade; the keratic precipitates may be pigmented or appear in coin-like pattern or develop nodular endothelial lesions but rarely vitritis. These eyes tend to have lower endothelial cell counts compared to the fellow eye. As the ocular manifestations are variable and may overlap considerably viral uveitis can pose a diagnostic dilemma. Thus, quantitative polymerase chain reaction or Goldmann-Witmer coefficient (levels of antibody) assay from aqueous humour samples are preferred to confirm the aetiology and determine the disease severity. There is no mention of different treatment strategies. 

Demystifying viral anterior uveitis: A review.
Chan N, Chee SP.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2019;47:320-33.