Study: Visual fields in nonarteritic ischemic optic neuropathy patients stable at 1 year

Visual fields of patients with nonarteritic ischemic optic neuropathy remain relatively stable after surgery or careful follow-up 1 year following the onset of disease, a prospective study found. Compared with eyes with normal fields, fellow eyes presenting visual field defects at disease onset do not appear to be at increased risk of developing the condition.

Roberta W. Scherer, PhD, and colleagues evaluated 1-year changes in visual fields in affected and fellow eyes of 258 patients with nonarteritic ischemic optic neuropathy and visual acuities of 20/64 or better enrolled in the Ischemic Optic Neuropathy Decompression Trial. Specifically, 127 of these patients received optic nerve decompression surgery and 131 patients were assigned to careful follow-up with no surgery.

An additional 160 nonrandomized patients with visual acuities worse than 20/64 were also followed for 1 year.

Reliable visual field measurements were obtained at baseline, 6 months and 12 months for 245 total participants: 179 who had been randomized to treatment and 66 who had not been randomized.

At 1 year, the investigators reported significant visual field changes in defect distribution within the central fields of randomized eyes (P = .02)

Among both randomized and nonrandomized eyes, superior and inferior altitudinal defects were less severe for the duration of follow-up than at baseline.

The investigators identified a significant association between changes in central field severity and changes in visual acuity from baseline to 6 months (P < .001) and 12 months (P = .01); however, they reported no significant correlation between visual field changes and treatment groups, age or comorbidities at disease onset.

Compared with eyes with defects, fellow eyes with normal visual fields were not at an increased risk of developing nonarteritic ischemic optic neuropathy, according to the study, published in the October issue of Ophthalmology.