Retinal Nerve Fiber Layer Thickness Change in Post–Optic Neuritis Patients

Abstract

Purpose: : To evaluate morphologic impairment of retinal nerve fibers due to optic neuritis (ON) by measuring the retinal nerve fiber layer thickness (RNFLT).

Methods: : The RNFLT around the optic disc was measured with GDx Access VCC (Laser Diagnostic Technologies, Inc., San Diego, CA) in 35 eyes of 25 post–ON patients (ON group) without active ON confirmed by fluorescein angiography; 32 eyes of 32 healthy subjects served as the control group. Four parameters, the temporal superior nasal inferior thickness (TSNIT) average, superior average, inferior average, and TSNIT standard deviation, were compared between patients with ON and the control group. These parameters also were compared between 19 eyes with recurrent ON and 16 eyes without recurrent ON. Correlations between the mean deviation (MD) of the Humphrey 30–2 full–threshold test and the parameters were investigated.

Results: : In the ON group, the 4 parameters decreased significantly compared with the control group (P<0.01). The parameters in the eyes with recurrent ON were significantly lower than in eyes without a recurrence (P<0.05). A correlation was found between the MD and each of the 4 parameters (P<0.01; correlation coefficient, 0.547∼0.732). An abnormal RNFLT was found in all eyes with visual acuity <20 /25, recurrent ON, or both.

Conclusions: : A decrease in the RNFLT indicates that inflammation affected the optic nerve fiber layer in eyes with ON. The RNFLT test may be useful to objectively evaluate nerve fiber impairment. Decreasing RNFLT indicates that inflammation influenced optic nerve fiber layer in eyes with optic neuritis. RNFLT test may be useful to evaluate nerve fiber impairment objectively.

Keywords: imaging/image analysis: clinical • nerve fiber layer • inflammation