Retinal Nerve Fiber Layer Thickness and Optic Disc Parameters in Anisometropic Amblyopia by Cirrus HD OCT in Pediatric Population

Background: To compare the peripapillary retinal nerve fiber layer (RNFL) thickness and characteristics of optic disc parameters in amblyopic and fellow eyes in pediatric patients with an isometropic amblyopia by Cirrus HD OCT. Method: This study was a prospective, cross-sectional, study including thirty-five subjects of newly diagnosed anisometropic amblyopia. All children underwent an ophthalmic examination that included visual acuity, and optical coherence tomography (Cirrus OCT Zeiss, 'Optic Disc Cube 200×200' protocol). Measurement of the Retinal nerve fiber layer and optic nerve head parameters (ONH) was done for both amblyopic and normal fellow eyes. Results: The mean best corrected visual acuity (log MAR scale) of the normal eyes and the amblyopic eye was statistically significant (P <0.001). The average RNFL thickness in the normal eye was 96.34 ± 9.3 µm (range 76 – 122 µm) while that of the amblyopic eye was 97.94 ± 11 µm (range 77-125 µm) which was not statistically significant (P=0.294). Among four quadrant and 12 o' clock hour sector analysis, nasal and temporal sector had significant difference between amblyopic and normal eyes respectively (P=0.027, P=0.045). Among the ONH parameters, the average cup-to-disc area ratio and cup volume was lesser in the amblyopic eyes than in the fellow eyes (P=0.042, P=0.023 respectively). None of the other ONH parameters were significantly different between the investigated eyes. Conclusions: There was no difference between average RNFL thickness in amblyopic and normal fellow eye. Some of the morphological measurements between the amblyopic and fellow eyes in patients with unilateral amblyopia were significantly different.