The visual performance and metamorphopsia of patients with macular holes.

Background: Most patients attain better visual acuity with the elimination of metamorphopsia after successful closure of a macular hole (MH) by vitrectomy.

Objective: To determine the presurgical visual function of eyes with an MH.

Methods: We examined 54 eyes of 51 patients with an idiopathic MH using the Amsler chart. We evaluated the types of subjective metamorphopsia and compared them with the clinical factors associated with MHs. In a prospective study, we performed a montage test on a separate group of 16 patients with unilateral idiopathic MHs. The patients were asked to choose, while viewing with their better eye, the computer-modified picture that best matched the unmodified image seen by the eye with the MH.

Results: From the results of the Amsler chart test, we divided the subjective changes into 2 types of metamorphopsia; of the 54 eyes, pincushion distortion (bowed toward the center) was found in 33 (61%), and unpatterned distortion (no specific pattern) was found in 21 (39%). Pincushion distortion was significantly associated with an MH of shorter duration (< or =6 months) (P = .03) and an early stage (stage 2) of MH formation (P = .02). A scotoma was hard to detect, and patients had difficulty describing their scotomata and distortions. In the montage test, patients with early MHs chose portraits modified with a pincushion type of distortion.

Conclusions: We found concentric pincushion metamorphopsia without subjective scotomata, which we suggest arises from an eccentric displacement of the photoreceptors. This accounts for the main characteristic of the visual performance of patients with idiopathic MHs.