Risk of decreased visual acuity in full-thickness idiopathic macular holes.

We studied 169 eyes of 149 patients with a full-thickness idiopathic macular hole to ascertain the risk factors of enlargement of the hole or the surrounding retinal detachment and subsequent decreased visual acuity. Eyes were divided as follows: group A, 48 eyes with no posterior vitreous detachment and a hole 400 microns or smaller; group B, 77 eyes with no posterior vitreous detachment and a hole 400 microns or larger; group C, 13 eyes with posterior vitreous detachment and a hole 400 microns or smaller; group D, 31 eyes with posterior vitreous detachment and a hole 400 microns or larger. In group A, the macular hole enlarged in 37 eyes (77%); the retinal detachment enlarged in 35 eyes (73%); and visual acuity decreased by two or more Snellen lines in 28 eyes (58%). These percentages were significantly higher than those in group B (P = .01, P = .01, and P = .01, respectively), group C (P = .02, P = .01, and P = .01, respectively), and group D (P = .01, P = .05, and P = .01, respectively). Eyes without posterior vitreous detachment with a full-thickness idiopathic macular hole 400 microns or smaller may have a greater risk of an enlarged macular hole, surrounding retinal detachment, and subsequent visual loss.