Association Between Contrast Sensitivity and Ganglion Cell–Inner Plexiform Layer Thickness After Resolution of Macular Edema Due to Branch Retinal Vein Occlusion

<b>Background/Objectives:</b> We sought to assess the relationship between contrast sensitivity (CS) and optical coherence tomography (OCT) findings, including ganglion cell-inner plexiform layer (GCIPL) thickness, in eyes with cystoid macular edema, secondary to branch retinal vein occlusion (BRVO-CME), treated with intravitreal ranibizumab (IVR). <b>Methods</b>: This prospective study included 44 patients with BRVO-CME who underwent treatment with IVR (three monthly injections and pro re nata) and were followed up for 12 months. We collected data on CS, best-corrected visual acuity (BCVA), and OCT findings (ellipsoid zone [EZ] and external limiting membrane status [ELM], central foveal thickness [CFT], and average GCIPL thickness) at the time of the final visit when macular edema was resolved. Multiple regression analysis was used to evaluate the relationship between visual functions and OCT findings, age, and lens status. <b>Results</b>: Multiple regression analysis revealed that lower GCIPL thickness was significantly associated with worse CS (β = 0.008; 95% CI, 0.002-0.014; <i>p</i> = 0.011), whereas this was not the case with BCVA. Lower CFT and mild cataracts were also associated with worse CS (CFT: β = 0.003; 95% CI, 0.001-0.004; <i>p</i> = 0.001; mild cataract: β = -0.182; 95% CI, -0.286--0.078; <i>p</i> = 0.001) and worse BCVA (CFT: β = -0.002; 95% CI, -0.003--0.001; <i>p</i> < 0.001; mild cataract: β = 0.079; 95% CI, 0.008-0.150; <i>p</i> = 0.029). <b>Conclusions</b>: GCIPL thickness may serve as a valuable biomarker for CS in eyes with BRVO-CME following IVR treatment.