The Impact of Intravitreal Injection of Ranibizumab on External Limiting Membrane, Ellipsoid Zone Integrity and Visual Acuity in Diabetic Macular Edema

Background: Ellipsoid zone (EZ) and external limiting membrane (ELM) integrity could be important predictors of visual function in Diabetic Macular Edema (DME). Ranibizumab intravitreal injection (IVI) showed the highest percentage of early EZ/ELM restoration. Aim: To evaluate the effect of Ranibizumab IVI on external limiting membrane, ellipsoid zone integrity and presenting visual acuity in DME patients. Methods: This study is Prospective observational clinical case series study conducted on A Simple Convenient sample of 30 eyes of 22 patients with DME and mean age of 56.0 (±9.3) years. Patients have been received three Ranibizumab IVI monthly. Full ocular examination was performed before and after one month of each injection. The required parameters have been evaluated qualitatively using Optical Coherence Tomography (OCT). Results: The photoreceptor status within 500 microns showed that 7 eyes with disrupted EZ out of 10 eyes (33.3%) at baseline turned continuous significantly. However, 3 eyes with Lost EZ (10.0%) remained lost. And 17 (57.7%) eyes had preserved intact EZ. Twenty one (70%) continuous ELM eyes of 30 at baseline had preserved intact ELM ; however 4 eyes with disrupted ELM out of 7 eyes (23.3%) at baseline had improved and become continuous (with 1eye with disrupted ELM turned lost and 2 eyes remained disrupted). Conclusion: EZ has been improved statistically significant after Ranibizumab IVI with corresponding improvement in best corrected visual acuity. ELM status had no statistically significant change; it had been maintained almost stable status after injection with corresponding stability of vision.