Abstract
Purpose::
VEGF has been implicated in retinal vein occlusion (RVO) by studies that have demonstrated elevated levels of VEGF and VEGF mRNA expression in eyes with RVO. These VEGF elevations are thought to be a response to ischemia. As a pro-angiogenic growth factor, VEGF causes increased vascular permeability and can stimulate neovascular growth. Macular edema arising from the increased permeability contributes to the vision impairment seen in RVO patients. Several short-term studies have demonstrated the promising effects of VEGF inhibitors in the treatment of RVO. Here we expand on these findings, reporting our experience up to 27 weeks with intravitreal bevacizumab (Avastin, Genentech) in the treatment of RVO.
Methods::
A retrospective review of 6 consecutive patients with RVO treated with intravitreal bevacizumab in a multispecialty private practice. Visual acuity and OCT measurements were documented at baseline and compared throughout the follow-up period. Quantitative central retinal thickness measurements and qualitative anatomic macular features were documented using Zeiss Stratus OCT3 fast and slow scans respectively.
Results::
Six eyes of 6 consecutive patients with a mean age of 68.7 years (range 47 to 89 years) were evaluated. Follow-up ranged from 7 to 27 weeks (average 17 weeks). Patients received a mean of 2.4 bevacizumab injections per eye (range 2-4). The average time between injections was 8 weeks. No systemic or ocular adverse events were observed. The mean baseline CRT was 591 µm and decreased to a mean of 376 µm at 4-7 weeks following the first injection (31.7% decrease, P<0.05). Retinal edema as documented by CRT recurred on average between 8-10 weeks to an average CRT of 582 µm. The baseline visual acuity ranged from CF 2' to 20/100 (mean logMAR = 1.6) and the acuity at 4-7 weeks, following the first injection, ranged from CF 4' to 20/50 (mean logMAR = 0.92; P<0.05), with every patient showing at least a halving of the visual angle. At 8-10 weeks following injections visual acuity was variable among patients.
Conclusions::
Intravitreal bevacizumab was safe as a treatment for RVO in this retrospective study of 6 patients with a range of 27 week follow up. Visual acuity and OCT measurements initially improved following intravitreal bevacizumab therapy but had a limited durability and benefit. The durability of the treatment effect was a mean of 8 weeks, after which macular edema recurred on OCT, and some patients with a corresponding decline in visual acuity. All patients exhibited improvements in vision and OCT with repeat injections, but recurred after a similar durability interval. Case image summaries will be presented.
Keywords: vascular occlusion/vascular occlusive disease • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)