Can retinal nerve fiber layer thickness be an indicator of amblyopia – Opening new horizons

To study the RNFL thickness in amblyopia at Institute of Ophthalmology, JNMCH, AMU, Aligarh.Prospective cross-sectional study.This study was conducted on 30 amblyopic children of age ranging between 6-16 years at Institute of Ophthalmology, Jawaharlal Nehru Medical College and Hospital, AMU, Aligarh after taking institutional ethical clearance and informed consent from parents of the patients. A brief clinical history was taken and detailed eye examination was done for visual acuity. Evaluation and quantification of strabismus was done. SD- OCT was performed after dilatation of pupil with 1% cyclomid eye drop on all enrolled children for evaluation of RNFL thickness and GCC thickness. RNFL thickness and GCC thickness of amblyopic eyes were compared with the fellow eyes. Data entry and analysis was done using paired t-test and p- values <0.05 was considered statistically significant. JASP application version 0.16.4.0 was used for statistical analysis of data and results.Out of 30 children23 were anisometropic amblyopic and 7 were mixed amblyopic. Average RNFL thickness was more in amblyopic eye as compared to fellow eye. This difference in RNFL thickness between the eyes remained statistically significant in an anisometropic amblyopic eyes (p<0.001) but not in mixed amblyopic eyes (p=0.50). No significant difference was found on comparing GCC thickness between the eyes in both the groups (anisometropic amblyopic and mixed amblyopic) (p=0.88,0.30). Amblyopic eyes have more RNFL thickness than fellow eyes. Therefore, we conclude that amblyopia may involve retinal structure, also exploding the old age myth that only cortical changes are responsible.