Purpose: To investigate the correlation between visual function and thinning of the retinal nerve fiber layer (RNFL) and the macular ganglion cell-inner plexiform layer (GCIPL) as measured by optical coherence tomography (OCT) in eyes with aquaporin-4 IgG-positive optic neuritis (AQP4-IgG-positive ON).
Study design: Prospective study.
Methods: Patients with a history of ON were categorized into 2 groups: the AQP4-IgG-positive group and the AQP4-IgG-negative group. Patients with multiple sclerosis were excluded. All patients underwent ophthalmologic examination and OCT imaging at least 6 months after the last episode of acute ON. Visual function and inner retinal structure correlations were analyzed using Pearson correlation and regression analyses.
Results: Thirty-one previous ON eyes of 17 AQP4-IgG-positive patients and 21 previous ON eyes of 15 AQP4-IgG-negative patients were registered. Visual function, especially the visual field, was better correlated with RNFL than with macular GCIPL. The best correlation between visual function and RNFL was the linear model, whereas the best correlation between visual function and GCIPL was the nonlinear model (inverse regression). Regression models revealed worse visual function in AQP4-IgG-positive ON than in AQP4-IgG-negative ON, whereas no differences in RNFL and GCIPL were found between the 2 groups.
Conclusions: RNFL measured by OCT can be a useful retinal structure for estimating and monitoring visual field loss in AQP4-IgG-positive ON patients, particularly in patients whose visual field cannot be quantitated. The correlation between visual function and the inner retinal structure of eyes with AQP4-IgG is unique and differs from that of eyes without AQP4-IgG.
Keywords: Aquaporin-4 antibody; Neuromyelitis optica; Optic neuritis; Optical coherence tomography; Visual function.