Diabetic papillopathy with macular edema treated with intravitreal bevacizumab.

Sir,

I would like to thank B. Joob and V. Wiwanitkit for their comments on the case report of “Diabetic papillopathy with macular edema treated with intravitreal bevacizumab”, which was published in Oman Journal of Ophthalmology, issue of September 2011.[1] They were concerned about two points: complications and cost of using intravitreal bevacizumab.

Complications from intravitreal bevacizumab have been reported in the literature, but are very rare and might not be related to the therapeutic agent itself. These include systemic and ocular adverse effects. Systemic adverse effects were observed during trials of anti-vascular endothelial growth factor (VEGF) injections. These included non-fatal myocardial infarctions, non-fatal strokes, and death from vascular causes. Results showed no significant difference in rates of these events between the group receiving sham injections and groups receiving various doses of ranibizumab, which is one of the anti-VEGF agents.[2] Other studies on intravitreal bevacizumab for neovascular age-related macular degeneration did not report any ocular or systemic adverse effects from the treatment.[3]

Ocular adverse effects are related to the procedure of injection and not to the therapeutic agent, which is a sterile solution. These are mainly endophthalmitis, retinal detachment, and vitreous hemorrhage. Subconjuctival hemorrhage, which is the most common post-injection side effect, is a very benign event that does not lead to any serious sequelae. It has a short term course. Endophthalmitis, which is a very serious emergency condition, was reported after intravitreal injections of anti-VEGF agents. On the other hand, it might occur after any intra-ocular intervention. In one large series of 14 866 injections, the risk of endophthalmitis was found to be 0.2% per injection.[4] In ANCHOR trial which was conducted to study ranibizumab in neovascular age-related macular degeneration, the endophthalmitis risk was 0.05% per injection.[5] In some series, the incidence was found to be as low as zero percent in 4690 injections.[6] In our institute, more than 250 injections have been given over 2 years, and no single case of endophthalmitis or retinal detachment has been recorded.

Incidence of retinal detachment after intravitreal injections is very low. A study of 35 942 injections reported a rate of 0.013% post-injection retinal detachment.[7] Vitreous hemorrhage, increased intra-ocular pressure, transient mild uveitis, and lens injury occur in less than 1% of patients.[8] Increased intra-ocular pressure is usually associated with intravitreal steroid injections.

As for cost, an intravitreal bevacizumab injection is very cheap compared to other intravitreal anti-VEGF injections. One intravitreal injection of bevacizumab costs less than 50$.[9]