Evaluation of Retinal Nerve Fibre Layer and Macular Thickness in Amblyopia

Abstract

Introduction: Amblyopia is reduced visual acuity in one or both eyes due to abnormal visual development in early part of life. Purpose of this study was to evaluate and compare the retinal nerve fibre layer (RNFL) and central macular thickness (CMT) between amblyopic and fellow (normal) eyes using spectral-domain optical coherence tomography (SD-OCT). Methods: This was a hospital based, cross-sectional comparative study conducted in the department of Ophthalmology, B.P. Koirala Lions Centre for Ophthalmic Studies (BPKLCOS), Institute of Medicine (IOM), Tribhuvan University Teaching Hospital (TUTH). All consecutive cases of age ≥5 years and ≤15 years diagnosed with unilateral amblyopia from January 2013 to June 2014 were included in this study. RNFL and macular thicknesses were measured using SD-OCT and compared between fellow eyes. Results: A total of 32 cases with unilateral amblyopia, 19 with hypermetropic anisometropic, 4 with myopic anisometropic and 9 with strabismic amblyopia were enrolled in the study. The mean age of presentation was 9.75±2.77 years. The mean CMT in amblyopic eyes (241±45.27 μm) was significantly greater than the normal fellow eyes (233.22±44.24 μm), p= 0.042. The difference remained significant in hypermetropic anisometropic group but not in myopic anisometropic and strabismic group. The mean RNFL thickness was similar in amblyopic (104.16±13.64 μm) and fellow eyes (104.03±13.06 μm). Conclusions: The CMT was significantly greater in the amblyopic eyes than the normal fellow eyes. There was no significant difference in the RNFL thickness between the amblyopic and normal eyes.