Study: Long-term visual outcomes favorable for optic neuritis patients, even if MS develops

The majority of optic neuritis patients can expect good long-term visual outcomes, even if they develop multiple sclerosis, according to 15-year results from the Optic Neuritis Treatment Trial.

"Those who develop MS are more likely than those who do not develop MS to exhibit abnormal findings on tests of visual function. However, even in those with MS, vision is normal about 60% of the time," the study authors said.

Robin L. Gal, MSPH, and colleagues at 13 participating ONTT centers performed neuro-ophthalmic examinations — including visual acuity, contrast sensitivity and visual field tests — on 294 patients with acute unilateral optic neuritis who had participated in the ONTT between 1988 and 1991.

These patients had been randomly assigned to receive one of two high-dose intravenous corticosteroid regimens or a placebo; they had been followed up annually through 1997 and again in 2001, 2002 and 2006. In addition, the researchers used the National Eye Institute Visual Function Questionnaire and Neuro-Ophthalmic Supplement to assess quality of life in these patients. The study was published in the June issue of Ophthalmology.

At final follow-up examination, patients averaged 48.9 years of age, and the time lapsed from ONTT entry ranged from 14.7 to 18.3 years.

At final follow-up, 72% of eyes affected with optic neuritis at baseline had a visual acuity of 20/20 or better and 66% of patients had a visual acuity of 20/20 or better in both eyes.

The researchers observed a visual acuity of 20/40 or worse in both eyes in six patients (2%), and a visual acuity of 20/200 or worse in both eyes in three (1%) patients.

Of 294 total participants, 37 patients were diagnosed as having MS at baseline and 111 patients subsequently developed MS during follow-up, the authors noted.

Among the 148 patients with MS, 39 were missing contrast sensitivity and 15 were missing visual field in the affected eye at final follow-up. Conversely, among the 146 patients without MS, 31 were missing contrast sensitivity and 12 were missing visual field in the affected eye.

In addition, 39 patients with MS were missing contrast sensitivity and 14 were missing visual field in fellow eyes. Among the 146 patients without MS, 31 were missing contrast sensitivity and 10 were missing visual field in fellow eyes, according to the study.

"On average, visual function was slightly worse among patients with multiple sclerosis than among those without MS. As expected, quality-of-life scores were lower when acuity was reduced and when neurologic disability from MS was present," the authors said.