Cytomegalovirus and Eye

Sir,

We read with interest the very comprehensive article by Carmichael on cytomegalovirus (CMV) and eye.¹ In addition to the clinical features reported by the author,¹ we would like to highlight some additional salient clinical points associated with CMV and eye.

With regard to clinical manifestation of CMV anterior uveitis, the iris atrophy is patchy or diffuse, with no posterior synechiae and no posterior segment changes.² It is usually associated with increased intraocular pressure.² Chee and Jap³ also reported the presence of an immune ring in the cornea of patients with CMV anterior uveitis. Nodular endothelial lesions are white, medium-sized, nodular lesions surrounded by a translucent halo, which are significantly associated with CMV infection in cases of chronic anterior uveitis.^{2, 3} Anterior uveitis with ocular hypertension resistant to topical steroid therapy and not clinically suggestive of the herpes group of virus makes the clinician suspect CMV infection.² CMV anterior uveitis responds to ganciclovir, but the relapse rate is high and prolonged therapy may be required. As reported by Jap and Chee,² ganciclovir gel induced a response in two-thirds, but uveitis recurred in 57% of acute and 25% of chronic inflammation. They recommended ganciclovir gel as first-line therapy in view of its minimal adverse effects and affordability.²

As mentioned by the author,¹ CMV is a neurotropic virus with predilection to the retina and central nervous system. Also reported in the literature is CMV-related optic neuritis.^{4, 5} CMV optic neuritis is a rapidly-blinding disease. CMV affects the optic nerve from an adjacent focus of peripapillary CMV retinitis and, concomitantly, peripheral foci of CMV retinitis may be noted.^{4, 5}

Oral valganciclovir has proven to be a new and highly efficacious alternative to the chronic administration of ganciclovir in patients with CMV retinitis. In addition to its excellent bioavailability and favourable pharmacokinetic profile, valganciclovir has also proved to be cost effective and is the most widely used drug in the armamentarium for the treatment of CMV retinitis.⁶ Valganciclovir has answered the great need of patients with CMV retinitis for an injection-free medication in the induction and maintenance phases of therapy.⁶