Functional evaluation with microperimetry in large idiopathic macular holes treated by a free internal limiting membrane flap tamponade technique

BACKGROUND: Free internal limiting membrane (ILM) flap tamponade technique is an alternative choice for treating large idiopathic macular holes (IMHs). However, the functional recovery related to this surgical approach is not well-characterized. This study aimed to evaluate morphological and microperimetric outcomes 6 months after free ILM flap tamponade technique for large IMHs. METHODS: Twenty-two patients (22 eyes) with large IMHs (minimal diameter > 400 μm) were retrospectively enrolled in this study. All patients underwent 23-gauge pars plana vitrectomy with ILM peeling and free ILM flap tamponade procedures. Snellen best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and MP-1 microperimetry were measured at baseline and 6 months after surgery. Associations of postoperative BCVA with retinal sensitivity were detected. RESULTS: Macular hole closure was achieved in 21 eyes (95.5%). Dislodgement of free ILM flap was found in non-closed eye. Mean logMAR BCVA improved from 1.10 ± 0.33 at baseline to 0.67 ± 0.32 at 6 months postoperatively (P < 0.001). The mean overall macular sensitivity and foveal fixation stability increased respectively from 8.58 ± 3.05 dB and 65.64 ± 17.28% before surgery to 11.55 ± 2.72 dB and 78.59 ± 13.00% at 6 months after surgery (P < 0.001). The mean change in foveal sensitivity (within 2°) was significantly greater than the change achieved for peri-foveal sensitivity (2° to 10°) by 1.50 ± 2.62 dB (P = 0.014). Linear regression analysis showed that postoperative logMAR BCVA was significantly associated with duration of symptom (B = 0.063, P = 0.001), preoperative logMAR BCVA (B = 0.770, P = 0.000), preoperative peri-foveal (B = − 0.065, P = 0.000) and foveal sensitivity (B = − 0.129, P = 0.000). Moreover, multiple regression model revealed that preoperative foveal sensitivity was independently associated with postoperative logMAR BCVA (B = − 0.430, P = 0.040). CONCLUSIONS: Vitrectomy combined with ILM peeling and free ILM flap tamponade technique results in effective morphological and functional recovery for large IMHs. Preoperative foveal sensitivity might be a prognostic indicator for postoperative BCVA.