PURPOSE: To describe the morphologic features of idiopathic macular holes and vitreous traction during macular hole evolution.

METHODS: We prospectively examined 89 eyes of 82 patients with idiopathic macular holes (stage 1, 15 eyes; stage 2, 16 eyes; stage 3, 50 eyes; stage 4, eight eyes) using optical coherence tomography. In addition to optical coherence tomography, scanning laser ophthalmoscopy was performed in all 15 eyes with stage 1 hole, six of 16 eyes with stage 2, and 19 of 50 eyes with stage 3.

RESULTS: In stage 1 eyes, optical coherence tomography revealed retinal split or cystic changes at the fovea in 11 of 15 eyes (73%) and foveal retinal detachment in four eyes (27%). Two eyes with foveal cysts progressed to stage 2, and one developed a stage 3 hole. In one eye with retinal detachment, the detached retina thinned and developed dehiscence. Optical coherence tomography showed a vitreous cortex that was detached in the perifoveal area but attached on the fovea in 11 of the 15 stage 1 eyes. In stage 2 macular holes, retinal tissue extending from the perifoveal retina formed a flap. Scanning laser ophthalmoscopy demonstrated intraretinal radiating striae, which corresponded to a foveal cyst or perifoveal cystic changes.

CONCLUSIONS: Macular holes start as retinal splits or foveal cysts in most cases. The anterior wall of the cyst serves as a flap in stage 2 and an operculum in stage 3 holes. Radiating striae correspond to retinal splits or cysts and presumably represent an elevation of Henle fiber. In a few macular holes, foveal detachment is the initial change. The detached retina thins and eventually develops a hole. In both courses, anterior traction of the slightly detached vitreous cortex appears to be a major contributing factor to macular hole formation.