PREDICTIVE OCT BIOMARKERS OF RETINAL CHANGES AND VISUAL OUTCOMES IN SILICONE OIL ENDOTAMPONADE IDENTIFIED BY ARTIFICIAL INTELLIGENCE.

PURPOSE: To quantify retinal layer changes and visual outcomes in eyes with silicone oil (SO) endotamponade for rhegmatogenous retinal detachment using OCT biomarkers and prediction models. METHODS: Seventy-six eyes with SO endotamponade underwent macular volume OCT at SO insertion and just before SO removal. An automated segmentation tool quantified retinal nerve fiber layer (RNFL), ganglion cell layer + inner plexiform layer (GCL+IPL), other retinal layers, and fluid (SRF, IRF). Eyes with and without macular edema (ME) during tamponade were compared. A random forest classifier explored predictors of categorical best-corrected visual acuity (BCVA) change (improved, stable, worsened). RESULTS: RNFL and GCL+IPL thinned significantly during tamponade (RNFL 35.4 ± 18.1 µm to 26.9 ± 19.1 µm; GCL+IPL 74.7 ± 17.4 µm to 55.8 ± 27.2 µm), while PR+RPE showed mild thickening (59.6 ± 12.6 µm to 61.4 ± 15.0 µm). Other layers and fluid compartments showed no clinically relevant change. ME occurred in 44/76 eyes (57.9%), but retinal layer changes and BCVA outcomes (improved/stable/worsened) were similar in ME and non-ME groups (χ2 p=0.94). In the prediction model, RNFL, GCL+IPL, and PR+RPE were the strongest contributors, whereas SO duration and ME status had minimal impact. CONCLUSION: SO endotamponade was associated with selective inner retinal thinning and mild PR+RPE thickening. Postoperative visual recovery depended mainly on inner retinal integrity, supporting OCT-derived layer biomarkers as practical tools for prognostication after SO removal.