Prognostic factors for visual recovery after successful large macular hole surgery using the inverted flap technique

The goal of our study is to describe the functional results and preoperative factors predicting visual recovery after successful inverted flap technique and closure of large full-thickness macular holes (FTMH) and to evaluate the correlations between microstructural foveal changes and final visual acuity.

Retrospective, descriptive, analytical study including 80 eyes of 78 patients with large FTMH; operated by inverted flap technique with successful closure of the macular hole after surgery. All eyes underwent a full preoperative ophthalmic examination and macular B-scan SD-OCT. We performed the classic inverted flap technique for all patients. Postoperatively, all patients were examined at 7 days, 1, 3, 6, 9 and 12 months after surgery. SD-OCT was performed for all patients on each follow-up. Preoperatively, best-corrected visual acuity (BCVA), FTMH size and basal hole diameter were the main outcome measures. Postoperatively, BCVA, macular thickness, integrity of the external limiting membrane (ELM) and ellipsoid zone (EZ) were recorded.

Mean age was 62±8.42 years with female predominance. Mean size of the FTMH was 692.59μm, and mean basal hole diameter was 1436.06μm. Mean BCVA improved from 1.06±0.491 LogMAR preoperatively to 0.52±0.32 at 9 months following surgery (P<0.001). At 9 months, the ELM was absent, partial or fully restored in 6.67, 10 and 83.33% respectively. The EZ was absent, partial or fully restored in 6.67, 33 and 63.33% respectively. ELM regeneration always preceded EZ regeneration at every point of follow-up. Final BCVA was statistically correlated with initial hole size (P=0.006, OR=1.056; CI [1.016-1.098]) and mean symptom duration prior to surgery (P=0.001. OR=0.987; CI [0.976-0.998]). Analysis of the ROC curve demonstrated that a hole diameter>478.5μm and symptom duration>5 weeks were correlated with non-improvement of visual acuity, with 81.3% sensibility and 18.7% specificity.

We report tomographic microstructural foveal changes and functional results following successful large idiopathic FTMH surgery using the classic inverted flap technique. Preoperative parameters such as initial FTMH diameter and mean symptom duration prior to surgery are crucial prognostic factors influencing final visual results.