Retinal nerve fiber layer thickness change in patients with wet AMD treated with ranibizumab, short term results Advantages: To determine the effect of ranibizumab injections on intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) thickness in patients with age-related macular degeneration (AMD) Methods: Fourteen eyes of 11 treatment naive patients with neovascular age related macular degeneration treated with ranibizumab were included in this prospective study. Patients who had optic nerve disease including glaucoma, elevated IOP, narrow angles, pigment dispersion or pseudoexfoliation and any ocular diseases or disorders that might affect RNFL thickness and measurements were excluded from the study. Patients were followed up by monthly examinations including visual acuity assessment with Snellen chart, biomicroscopic and fundoscopic examinations. Intraocular pressure was measured with applanation tonometer at baseline and before and 1 hour after each intravitreal injection. RNFL thickness was measured by time domain optical coherence tomography (Startus OCT, Carl Zeiss Meditec Inc, Dublin,CA) at baseline examination and before injections. Intravitreal ranibizumab injections were done as on needed basis. Central-superior-temporal-nasal-inferior RNFL thicknesses and IOP change with ranibizumab injections were analysed. Özen Osmanbaşoğlu, MD 1 Zeynep Alkın, MD 2 Ahmet Taylan Yazıcı, Ass. Prof. 2 Hülya Güngel, Prof. Dr 1 1.Istanbul Education and Research Hospital 2.Beyoglu Eye Training and research Hospital Effectiveness and safety: The mean age of patients were 76.5±10.5 years. The mean follow up time was 5.3±1.1 months and mean number of injections were 3.3±0.9. Mean IOP was 16.2±2.05 mmHg and during the follow up IOP change was insignificant, none of the patients experienced an IOP spike of 5 mmHg or more and none of them required antiglaucomatous medication. Baseline RNFL thicknesses were 96.8±8.5µm in the central, 117.2±16.2µm in the superior,, 71.2±14.4µm in the temporal,76.5±16.9µm in the nasal and 119.7±23.8µm in the inferior quadrant. The decrease in average and superior quadrant RNFLthickness after the first injection was statistically significant ( p: 0.01,p:0.04) From second to third injection average RNFL thickness did not change according to baseline, but significant decrease was observed in superior quadrant measurements according to baseline (p:0.04,0.02,0.04 respectively). During the follow up there were not a significant change in RNFL thickness in the other quadrants.. Take a home message: As the early spikes of IOP after injection usually returns to baseline within minutes, and the IOP was measured 1 hour after the injection in our study, may be we could not observe such spikes in our patients. But none of the patients experienced an increase of 5 mmHg or more one hour after treatment. So significant thinning of RNFL may be attributed to the direct toxic effect of the drug. RNLFBaselineFirst injectionSecond injectionThird injection Average (µm)96.85(8.5)92.9(7.2)94.1± ±10.5 Superior (µm)117.2(16.3)110.35(14.7)112.0± ±11.7 Temporal (µm)71.23(14.4)71.57(14.3)72.4± ±13.6 İnferior (µm)119.7(23.8)119.28(18.3)120.2± ±11.7 Nasal (µm)76.5(16.1)74.2(12.9)76.4± ±12.8