Purpose: To better understand the process of macular hole opercula formation by both optical coherence tomography and intraoperative observations.
Methods: Seventy-nine eyes of 71 consecutive patients with stages 1 to 3 idiopathic macular holes were studied using optical coherence tomography (OCT). In eyes with stage 1 or 2 holes undergoing vitrectomy, meticulous observation of the posterior hyaloid and the macular hole was carried out before and after peeling of the posterior hyaloid.
Results: In 6 of 12 eyes with stage 1 holes, OCT showed tiny steps on the anterior wall of the foveal cyst, connecting to the detached posterior hyaloid face. In eyes with stage 2 holes, opercula were incompletely detached and connected to the hole edge. In eyes with stage 1 holes that were operated on, a small semitransparent opacity was noted at the posterior hyaloid face after peeling of the posterior hyaloid in the absence of defects of the anterior wall of the cyst. In 10 of 12 eyes with stage 2 holes undergoing vitrectomy, the size of the foveal opening remained unchanged after peeling of the posterior hyaloid, and a semitransparent opacity was observed at the detached hyaloid face. All opercula in stage 3 holes that were clearly imaged by OCT were positioned above the plane of the posterior hyaloid face.
Conclusions: These findings suggest that the anterior wall of an evolving macular hole is composed of two layers: a prefoveolar membrane and the inner retinal layer. The prefoveolar membrane may play an important role in both persistent vitreofoveal adhesion and macular hole opercula formation.