A comparative Cross-Sectional Study on Amblyopia and its relationship with Retinal Nerve Fiber Layer Thickness

Abstract Background: Amblyopia affects approximately 1.75 percent of the world's population. Atrophic alterations in the lateral geniculate nucleus have been observed in amblyopic eyes, leading to the hypothesis that RNFL thickening is caused by a limitation of normal postnatal ganglionic cell reduction. To determine and compare the thickness of the retinal nerve fiber layer (RNFL) in all type of amblyopic and non-amblyopic eyes. Methods: A comparative cross-sectional study was conducted at Al-Shifa Trust Eye Hospital Rawalpindi over six months. Data were collected from 70 patients (140 eyes) using clinical structured Performa. RNFL thickness was measured using Optical Coherence Tomography (OCT). All the amblyopic patients were included in this study. A One-way ANOVA and paired sample t-test were applied to compare the RNFL thickness between different types of amblyopia and compare it with the non-amblyopic eyes. Results: The mean age of the patients was 10.20±2.811 ranging from 5 to 16 years. The mean thickness of RNFL globally in strabismus amblyopia was 108.1±14.1 whereas 108.1±10.1 micrometers, and there is no statistical mean difference between thickness with a p-value > 0.05. The mean value of RNFL thickness in anisometropia amblyopia for nasal, temporal, supra-temporal, supra-nasal, inferonasal, inferotemporal quadrants and for globally is 85.82±20.7, 75.67±14.5, 135.38±16.4, 121.05±30.2, 126.18±28.5, 143.92±17.1 and 105.74±11.1 respectively. There was no statistically significant difference found between the thickness of different types of amblyopia Conclusion: There is no significant difference in RNFL thickness between different types of amblyopia. Similarly, there is no significant difference in the thickness of RNFL in amblyopic and non-amblyopic eyes as well. So RNFL thickness is not affected in children due to amblyopia.