OCT based Comparison of RNFL Thickness in Low to Moderate Myopic Eyes with NORMAL and Raised IOP

Purpose: To compare Retinal Nerve Fibre Layer (RNFL) thickness with Optical Coherence Tomography (OCT) in low to moderate myopic eyes with normal & raised Intra Ocular Pressure (IOP) without any other glaucomatous changes. Methods: A Total of 60 low to moderate myopes (spherical equivalent [SE] between -6.0D & -0.5D) with 30 subjects with normal IOP (≤ 21 mmHg) and 30 with raised corrected IOP (≥22mmHg) were included in this cross-sectional study. Three circular scans were obtained for each eye at diameter of 3.4mm around the optic disc using RTVue OCT. A single index of average RNFL thickness throughout 360 degree was obtained. The mean RNFL of (n=60) eyes with raised IOP was compared with age matched randomly selected (n=60) eyes with normal IOP. Results: Mean RNFL was significantly thinner in eyes with raised IOP than in eyes with normal IOP, 91.01 ± 11.95 and 101.52 ± 10.13 respectively. Conclusion: These findings suggest that quantitative differences in RNFL thickness exist between age-matched low to moderate myopic eyes with normal and raised IOP. Thus, all myopic individuals with raised IOP should be considered for OCT to assess for damage of RNFL, as they are at risk of developing glaucoma in future.