The role of the premacular liquefied pocket and premacular vitreous cortex in idiopathic macular hole development.

PURPOSE

To clarify the role of the vitreous in idiopathic macular hole formation.

METHODS

We prospectively evaluated the vitreous before and during vitreous surgery in 64 consecutive eyes of 62 patients (stage 1B, four eyes; stage 2, ten eyes; stage 3, 43 eyes; stage 4, four eyes) with macular holes; another three eyes underwent a second vitrectomy. After core vitrectomy, the premacular vitreous cortex was examined by applying gentle suction. The detached posterior hyaloid face was observed under endoilluminiation.

RESULTS

We observed in all eyes a liquefied lacuna anterior to the posterior fundus before and during vitreous surgery. The premacular vitreous cortex was extremely thin and elastic upon gentle suction. A premacular ring, the diameter two to four times that of the Weiss ring, was observed in 48 of 57 eyes (84%) with stages 1B, 2, and 3 macular hole. In most cases, the vitreous cortex within the premacular ring either was absent or had a break, resulting in a premacular round defect. The vitreous cortex peripheral to the premacular ring, which was thick and less deformed, never showed a break. In eyes that had undergone a second vitrectomy, we noted residual cortex or an epiretinal membrane around the macular hole.

CONCLUSIONS

The premacular vitreous cortex is extremely thin and elastic. It is sharply demarcated by a ring from the thick peripheral vitreous cortex. Tangential traction, which causes macular holes, appears to originate exclusively in the premacular vitreous cortex that forms the posterior wall of the premacular liquefied pocket.