Unilateral amblyopia: An optical coherence tomography study

Purpose: To determine whether retinal nerve fiber layer thickness (RNFLT), macular thickness (MT), and foveal volume (FV) in patients with unilateral amblyopia differ between the amblyopic and the sound eye. Methods: A Humphrey-Zeiss Stratus (OCT3) with software 4.0.3.1 was used to evaluate 40 patients (17 male, 23 female; mean age, 15.2 years; range, 5-56 years) with unilateral amblyopia. Patients were divided into 2 groups: 20 strabismic and 20 anisometropic. Maps of macular thickness and RNFL thickness (3.46) created by the use of optical coherence tomography were applied to calculate FV and MT and RNFLT. Results: Mean best-corrected visual acuity was +0.3 LogMAR (range, +0.2 to +1.0) in the amblyopic eye. Mean RNFL thickness was not significantly different between eyes in either group. In strabismic amblyopia, mean MT and FV were 5% lower in the sound eye than in the amblyopic eye (MT, 267 μm vs 253 μm, p = 0.005; FV, 2.57 mm 3 vs 2.43 mm 3, p = 0.001). In anisometropic amblyopia, there was no significant difference between eyes in either MT or FV. Conclusions: In patients with strabismic amblyopia, the MT and FV were slightly but significantly lower in the sound eye than in the amblyopic eye. The clinical importance of this difference is not known. No such difference was observed in patients with anisometropic amblyopia. © 2009 American Association for Pediatric Ophthalmology and Strabismus.