External limiting membrane aperture as a reliable and predictive prognostic factor in macular hole surgery

PurposeTo evaluate the role of external limiting membrane aperture (ELMA) as a prognostic factor for the anatomical and functional outcomes of full thickness macular hole (FTMH) surgery.DesignRetrospective.Methods120 eyes of 120 patients who underwent surgery for idiopathic FTMH were enrolled. Best corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) scans were evaluated preoperatively and postoperatively at 3 and 12 months. Statistical analysis was performed to correlate the following preoperative parameters with 12-months postoperative BCVA and anatomical results: ELMA, apical hole diameter (AD), base hole diameter (BD), macular hole index (MHI), tractional hole index (THI), height (H), diameter hole index (DHI), hole form factor (HFF) and preoperative BCVA.ResultsPrimary successful MH closure was achieved in all the eyes. Postoperative BCVA showed a statistically significant increase from a preoperative logMAR median (IQR) value of 0.70 (0.52-1.00) to 0.18 (0.10-0.34) at 3 months and 0.16 (0.05-0.30) at 12 months. As demonstrated by ROC curves analysis, ELMA revealed to be a good predictor for 1B and 1C types of MH closure when its value was greater than 369 µm. Moreover, ELMA sizes above 369 µm were strongly associated with a postoperative BCVA less than 20/40.ConclusionsELMA appears to be a reliable prognostic factor for postoperative anatomical and functional outcome in FTMH surgery.