Impact of Retinotomy on Retinal Displacement after Macula-Involving Retinal Detachment Repair: Post Hoc Analysis of the PostRD Trial

Purpose: To explore the effect of subretinal fluid drainage on the amplitude of retinal displacement and distortion following macula-involving retinal detachment repair. Methods: Post hoc analysis of the PostRD trial - patients who underwent a drainage retinotomy at the surgeon’s discretion were compared to break drainage. Primary outcome - amplitude of retinal displacement on autofluorescence imaging at 6 months postoperatively. Secondary outcome measures - operative success; visual acuity; objective Distortion Scores & OCT imaging outcomes. Results: 262 patients recruited, 69 underwent drainage retinotomy. Re-detachment occurred in 11/69 (16%) of the retinotomy group versus 12/193 (6%) of the non-retinotomy group. Regression analysis revealed the extent of RD to be the only risk factor for failure. Failures were excluded. At 6 months, the retinotomy group had a lower amplitude of retinal displacement (P 0.02). Multivariable regression analysis showed that face down positioning and drainage retinotomy were both independent predictors for reducing amplitude of retinal displacement (P <0.01 and P 0.038) respectively, whilst extent of RD was a significant predictor for an increase in displacement (P 0.003).Visual acuity was higher in the retinotomy group (77 letters vs 74 non-retinotomy P 0.04) but similar when phakic patients were excluded (P 0.35). Objective D-Chart Distortion scores were lower (p=0.002). Retinal folds were more common in the retinotomy group (14.5% vs 8.7% non-retinotomy [P 0.004]). Conclusion: Retinotomy may be associated with a lower amplitude of displacement and lower distortion despite a higher incidence of retinal folds. No association was found between retinotomy and retinal re-detachment.