TOPLINE:

Worsening of vision occurred within a few weeks after onset of symptoms in most eyes with nonarteritic anterior ischemic optic neuropathy (NAION) that progressed. Only a past episode in the other eye, not common cardiovascular factors, was linked to an increased risk for deterioration of vision.

METHODOLOGY:

• In this secondary analysis, researchers reviewed data from a randomized controlled trial of an investigational therapy for acute NAION to determine how often and how soon vision worsened after onset of symptoms in the untreated eyes and to explore risk factors.
• They included 599 untreated eyes from adults aged 50-80 years (68% men) with new NAION in one eye, evaluated within 14 days of onset of visual symptoms. A subgroup of 167 eyes that received a sham-injection with no active drug was reassessed within the first 22 days and up to 2.5 months after onset of visual symptoms.
• Researchers measured best-corrected visual acuity using ETDRS charts and automated visual fields. They assessed progression as losing 10 or more ETDRS letters, 15 or more ETDRS letters, or having a significant worsening of the visual field.
• They also examined the influence of cardiovascular risk factors such as diabetes, hypertension, and smoking, as well as eye problems such as prior NAION in the other eye on the risk for worsening vision.

TAKEAWAY:

• By 14 days after onset of visual symptoms, 7.3% of eyes lost 10 or more ETDRS letters, and 4.1% lost 15 or more letters. In the sham-injection subgroup, by 2.5 months of onset of visual symptoms, 21.6% of eyes lost 10 or more letters, and 14.4% lost 15 or more letters.
• In the sham-injection group, 91.6% of eyes that lost 10 or more letters by 2.5 months had already worsened within the first 22 days after onset of visual symptoms.
• By 14 days after onset of visual symptoms, visual fields worsened in 32.1% of eyes, remained stable in 66.1% and improved in 1.8%. In the sham-injection group, visual fields worsened in 35.2% of eyes by 2.5 months after onset of symptoms.
• Prior NAION in the fellow eye was the only consistent factor associated with an increased risk for worsening vision (P = .0058). None of the cardiovascular factors was associated with an increased risk for NAION progression.

IN PRACTICE:

“As NAION has no proven treatment, it is useful to be able to counsel patients that if they have not had progressive visual acuity loss (loss of ≥ 10 ETDRS letters) within the first 3 weeks after onset of visual symptoms, there is less than a 10% chance of subsequent progression (≥ 10 ETDRS letters),” the researchers wrote.

SOURCE:

The study was led by Zoë R. Williams, MD, of University of Rochester School of Medicine in Rochester, New York. It was published online on January 14, 2026, in the American Journal of Ophthalmology.

LIMITATIONS:

Data on day 8 visual field testing was not collected, which limited assessment of whether visual field worsening after day 1 mainly occurred within the first 3 weeks. The study was not adequately powered to address questions beyond the original trial design. The small number of sham-treated eyes with progression limited multivariable analyses and may have biased results toward predicting nonprogression.

DISCLOSURES:

This study was sponsored by Quark Pharmaceuticals, Inc. The study received funding from multiple sources including the New York Eye and Ear Infirmary Foundation, Research to Prevent Blindness, and Shulman Family NAION Fund. Several authors reported being on the advisory board, consulting for, receiving honoraria from, or having other financial ties with multiple pharmaceutical and healthcare companies including the sponsor.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.