Extent of Internal Limiting Membrane Removal and Its Impact on Outcomes of Macular Hole Surgery

This randomized clinical trial was performed at a single center. Patients who were scheduled for surgery for idiopathic macular hole (MH) were enrolled. Eligible patients were equally randomized to small extent group or large extent group depending on the extent of ILM to be removed. Random numbers were generated through computerized block-randomization.

A standard 3-port pars plana vitrectomy was performed by a single surgeon using 23-gauge vitrectomy system, with a 1-step scleral tunnel incision. After posterior vitreous detachment was achieved, peeling of the ILM was performed by an end gripping forceps with the assistance of indocyanine green dye. The ILM was peeled in round shape with the radius of either 0.75-disc diameter or 1.5-disc diameter centering at the center of the MH according to the pre-assigned group. This was followed by a complete fluid-gas exchange, and all patients were encouraged to maintain a face-down position for at least 5 days postoperatively.

Postoperative measurements of BCVA and M-score were conducted at 2- and 6-month follow-up visits by independent masked observers. The first postoperative SD-OCT scanning was usually conducted at 1 to 2 weeks after operation according to the intraocular gas status. Then, OCT scans were conducted at follow-up visits 2, and 6 months postoperatively. The same experienced examiner conducted all the OCT scans on all subjects.

Comparison of anatomical closure, BCVA, M-score, Δ BCVA, and Δ M-score were primarily performed between the two groups. Then, the parameters measured from OCT scans with changes in ETDRS visual acuity and M-score were analyzed.