Clinical Characteristics of HIV-Associated Optic Neuritis

INTRODUCTION: Acute optic neuritis (ON) has been increasingly reported in patients infected with human immunodeficiency virus (HIV). We aimed to describe clinical characteristics of HIV-infected patients with ON. MATERIALS AND METHODS: This observational retrospective study was performed from January 2008 to January 2016 in a university hospital in Bangkok, Thailand. Demographic data and clinical manifestations were retrospectively reviewed. RESULTS: We included 10 HIV-infected patients and divided them into two groups: infectious and non-infectious ON. There were six patients in the infectious ON group (five males, mean age 33.6 years, median CD4 cell counts during ON episodes 36.5 cells/µL, high viral loads, median initial visual acuity [VA] 1.7, median VA difference [initial VA – follow-up VA] 0). Four patients developed cryptococcal meningitis and 2 developed neuro-syphilis. They were treated with amphotericin B plus fluconazole and penicillin G sodium, respectively. There were four patients in the non-infectious ON group (two males, mean age 44.3 years, median CD4 cell count during acute ON 157.5 cells/µL, undetectable viral loads, median initial VA 1.3, and median VA difference 1.2). They were given corticosteroid treatments. There were no statistically significant differences between the two groups with respect to age, sex, and initial VA. There were statistically significant differences in median VA difference and median CD4 cell counts between the two groups (p=0.02 and 0.03, respectively). There was a significant correlation between CD4 counts and duration in three non-infectious ON patients treated with antiretroviral therapy (ART, p<0.001). DISCUSSION: Patients with infectious ON had low initial CD4 counts and high viral loads. Patients with non-infectious ON had increasing CD4 cell counts and undetectable HIV viral load following ART. The findings are highly suggestive of immune reconstitution inflammatory syndrome. The CD4 cell counts and viral loads may help to identify the type of acute ON in HIV-infected patients and establish proper therapies.