Retinal Nerve Fiber Layer Thickness in Amblyopic Eyes

PURPOSE: To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of amblyopic and fellow eyes. We hypothesized that the RNFL of the amblyopic eye may be thinner. DESIGN: Prospective, cross-sectional, observational case series. METHODS: Optical coherence tomography of the peripapillary RNFL thickness of amblyopic and fellow eyes was performed in 37 patients 7 to 12 years of age (mean age standard deviation, 9.2 +/- 1.5 years) with unilateral strabismic, anisometropic, or combined-mechanism amblyopia enrolled in a randomized treatment trial. RESULTS: Mean global RNFL thickness of the amblyopic and fellow eyes was 111.4 and 109.6 mu m, respectively (mean difference, 1.8 mu m thicker in the amblyopic eyes; 95% confidence interval, -0.6 to 4.3 mu m). The amblyopic eye was 8 mu m or more thicker than the fellow eye in 9 patients (24%); the fellow eye was 8 mu m or more thicker than the amblyopic eye in 2 patients (5%); and the difference was within test-retest variability (7 mu m) in 26 patients (70%). CONCLUSIONS: Our findings do not indicate that peripapillary RNFL thickness is thinner in eyes with moderate amblyopia compared with their fellow eyes. (Am J Ophthalmol 2009;148:143-147. (C) 2009 by Elsevier Inc. All rights reserved.)