Highly viscous fluid in macular holes.

We describe a highly viscous fluid inside the macular hole and document that disappearance of this viscous fluid results in concentric macular hole closure. Twenty eyes of 20 patients (64.9 +/- 6.9, 54-73 years) with macular holes who underwent 25-gauge (25G) transconjunctival vitrectomy were studied. Macular holes were Gass stage 2 in 4 eyes, stage 3 in 11, and stage 4 in 5. After peeling the internal limiting membrane around the macular hole, fluid was aspirated from the edge of the macular hole using a 25G soft tip cannula while performing fluid-air replacement. During aspiration, a highly viscous fluid was observed in all cases irrespective of stage. After several aspirations of this viscous fluid, the fluid cuff flattened and the macular hole closed in a concentric manner. The viscous fluid showed the "sticky sign" resembling the thread formation of melted cheese. After replacing the vitreous with octafluoropropane and keeping the patient in a prone position for 1 day, the macular hole showed full closure in all cases. Disappearance of subretinal viscous fluid accompanied by flattening and concentric displacement of the fluid cuff is associated with closure of macular hole.