The effect of intravitreal ranibizumab on retinal nerve fiber layer thickness in exudative age related macular degeneration

Purpose: To evaluate the long term effect of intravitreal Ranibizumab on the retinal nerve fiber layer (RNFL) in exudative age related macular degeneration (AMD).Material and Methods: Patients with neovascular AMD in one eye and naive of treatment were enrolled into the study. At baseline best corrected visual acuity, intraocular pressure, central corneal thickness were measured in all patients. Following three monthly intravitreal Ranibizumab injections, the patients were evaluated according to disease activity and reinjections were performed according to ?treat and extend? protocol. During the follow up; best corrected visual acuity, intraocular pressure, central macular thickness and peripapillary nerve fibre layer thickness measurements were compared with normal fellow eyes. Variance analysis was used to evaluate the differences during follow up time. Furthermore subgroups were analyzed according to the number of injections.Results: 44 eyes of 11 women and 11 men with the mean age of 66,3 ± 8,8 years (50-80) were enrolled into the study. All patients had completed at least 12-month of follow-up time. Patients received an average of 4,7 (3-11 injections) intravitreal injections. Visual acuity was preserved or increased in 91% of cases during the follow-up. In 9% of cases visual acuity decreased less than three lines. The maximum visual acuity increase was recorded in the third month and preserved during twelve months of follow-up. At baseline and during the follow up there was no statistically significant difference in terms of intraocular pressure between two groups (p=0,774). At baseline, no significant difference was observed between two groups for RNFL thickness which was assessed as quadrants and globally (p=0,814). In each group there was a significant RNFL thinning (p=0,009 and 0,022) after the third month, while no significant difference was observed between treated and untreated eyes. Also the treatment was classified according to the number of injections, and RNFL thickness showed no difference between eyes treated with less or more than 5 intravitreal injections (p=0,757-0,953).Discussion: Although there was no statistically significant difference in RNFL thickness between study and control eyes during 12 months of follow up, a significant thinning compared to baseline values was recorded in both groups. With a larger sample size and by defining both groups in different patients the ?VEGF neutralization and inhibition of neuroprotection? hypothesis should be investigated in detail.