Abstract
Purpose: :
Intravitreous monoclonal anti-vascular endothelial growth factor (VEGF) antibodies or antibody fragments (ranibizumab, bevacizumab) have become the treatment of choice for choroidal neovascularization secondary to age-related macular degeneration. However, VEGF has also been shown to be neuroprotective in the central nervous system. Furthermore, pre-clinical studies have shown significant retinal ganglion cell loss following 6 weeks of systemic or intravitreous VEGF blockade. To investigate the possible deleterious effect of anti-VEGF agents in vivo we prospectively measured the retinal nerve fiber layer in patients receiving these intravitreous agents by optical coherence tomography (OCT).
Methods: :
Patients requiring intravitreous anti-VEGF for the treatment of choroidal neovascularization in a single eye had pre-treatment measurement of the average thickness of the peripapillary retinal nerve fiber layer (RNFL) in both eyes with the Stratus OCT (Carl Zeiss Meditec, Inc, Dublin, California, USA) using version 4.0 software and the fast scan protocol. The fellow, untreated eye of each patient served as a control. Measurements of the RNFL in 7 patients (14 eyes) were taken pre-treatment and at 3 months post-treatment.
Results: :
The average RNFL thickness of the treated eyes pre-treatment and at 3 months post-treatment was 92.55 microns and 92.38 microns, respectively (p=0.93). The average RNFL thickness of the untreated eyes at the same time points was 92.82 microns and 92.48 microns, respectively (p=0.90). There was no statistically significant difference in average retinal nerve fiber layer thickness change between treated and control eyes (p=0.96).
Conclusions: :
Intravitreous anti-VEGF therapy does not cause a significant change in retinal nerve fiber layer thickness within 3 months of treatment. Longer follow-up is necessary to determine if there is a decrease in RNFL thickness over time or if repeated treatment has a deleterious effect.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer • vascular endothelial growth factor