By Khalid F. Tabbara, MD
This retrospective study reports on the results of intravitreal ganciclovir injections of HIV-positive patients in Singapore with newly diagnosed cytomegalovirus (CMV) retinitis who had not used highly active antiretroviral therapy (HAART). The results, published in March in Ophthalmology, indicate that the therapy is safe and effective with minimal side effects. The authors propose it as a viable low-cost option in developing countries where newer options of sustained-release implants and oral valganciclovir are unavailable or prohibitively expensive.
The study included 24 patients (34 eyes). They received standard induction therapy of 2.0 mg/0.04 ml of intravitreal ganciclovir twice a week for four weeks. This was followed by a weekly maintenance regimen of 1.0 mg/0.02 ml of intravitreal ganciclovir.
The median number of intravitreal injections per patient was 30. The median follow-up was 95 days (mean, 207.9 days), while median time to progression was 152 days (mean, 380.1 days). This compares favorably to progression with traditional intravenous therapy (22 to 125 days), ganciclovir implants (seven months) and valganciclovir (160 days).
Three eyes developed rhegmatogenous detachments but none developed endophthalmitis. Contralateral involvement of CMV retinitis occurred in 17.6 percent of the patients.
Visual acuity improved or remained the same in 22 eyes (64.7 percent). The remaining eyes lost two or more lines of Snellen visual acuity. Eight-eight percent of patients achieved clinical resolution of CMV retinitis. Eighty percent achieved stable or improved visual acuity after induction therapy.
The use of HAART and oral valganciclovir in the treatment of CMV disease in AIDS patients has greatly reduced the incidence of CMV retinitis. However, oral valganciclovir is expensive in certain countries and sometimes inaccessible. The authors estimate that the cost for intravitreal injections over a six-month period was 11.7 percent that of sustained-release implants for unilateral treatment and 11.1 percent that of daily continuous intravenous infusions and oral valganciclovir for bilateral treatments. They found that the annual cost of intravitreal injection was $1,650 compared to $7,634 for sustained-released implant, $15,844.15 for intravenous injections and $16,240 for oral valganciclovir.
They conclude that the preservation of vision in these patients translates to an improved quality of life along with the elimination of the need for chronic indwelling catheters and intravenous therapy. However, prospective clinical trials are needed to assess the long-term safety and efficacy of this therapeutic regimen.