Study of Risk Factors, Clinical Profile and Visual Outcome in Cases Of Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION) at Tertiary Care Centre in Bihar.

Abstract

Background

Nonarteritic anterior ischemic optic neuropathy (NAION) is an acute, painless monocular vision loss condition that primarily affects middle-aged and elderly individuals. Major risk factors include hypertension, diabetes, and nocturnal hypotension. Identifying and managing these risk factors is crucial due to the disease’s guarded prognosis.

Methods

This prospective observational case series was conducted at a tertiary care center in Bihar. The study involved 20 eyes of 20 patients presenting with vision loss and disc edema. Comprehensive ophthalmic evaluations were conducted, including visual acuity, pupil assessment, color vision using the Ishihara chart, visual field assessment by Humphrey Field Analyzer (HFA), and fundus examination. NAION diagnosis was confirmed by the presence of relative afferent pupillary defect (RAPD), defective color vision, hyperemic or pallid disc edema, and visual field defects. Visual acuity was assessed at baseline and at six months follow-up. Statistical analysis was performed using SPSS software version 18.

Results

The mean age of patients was 58.50 ± 8.118 years, with a slight male predominance (52%). Hypertension (56%) and diabetes (68%) were the most common comorbid conditions. Inferior altitudinal visual field defects were the most prevalent (64%). Visual acuity improved significantly over six months (P = 0.000), with a three-line Snellen acuity improvement observed in 16% of patients. Better visual outcomes were associated with hyperemic disc edema and superior field defects, while poorer outcomes were linked to pallid disc edema and very poor initial visual acuity.

Conclusion

The study underscores the importance of managing systemic risk factors like hypertension and diabetes to improve visual outcomes in NAION patients. Despite the absence of specific treatments, controlling these risk factors may help reduce ischemic damage and prevent recurrence in the affected and fellow eyes.