2M.D. Asistant, Istanbul University Faculty of Medicine, Department of Ophthalmology, Istanbul/TURKEY Purpose: To determine retinal nerve fiber layer thickness and its correlation with spherical equivalent and axial length in high myopic patients.
Materials and Methods: The study includes 21 eyes of 12 high myopic (≥6 diopter or axial length ≥26 mm) patients and 20 eyes of 12 healthy volunteer. Retinal nerve fiber layers were measured from superior, inferior, temporal, nasal quadrants respectively by using spectral domain optical cohorence tomography. Mean RNFL thicknesses wre recorded. Statistical analysis was performed. Litmann formula was used for correction of axial length related ocular magnification effect.
Results: The mean age and axial length in high myopia group were 39.8±6.4 years (range 28-58 years) and 29.3±2.3 mm (range 26 - 32 mm), respectively. RNFL thicknesses of high myopic eyes in superior, inferior, temporal and nasal quadrants were 116.7±5.1 μm, 115.4±5.3 μm, 80.1±12.4 μm and 68.3±8.5 μm, respectively. Mean RNFL thickness in high myopia and control groups were 97.8±6.4 μm and 114.3±5.7 μm , respectively. The mean RNFL thickness in high myopia group was found to be quite more thinner than emethropic control group. It was observed that as the axial length and spherical equivalent get increase, the mean RNFL thickness gets thinner.
Conclusion: It is observed that the RNFL thickness values change in relation with the degree of myopia. Thats why, while investigating the damage emanating from glaucoma, especially in myopic patients, these variabilities should be taken into consideration.
Keywords : Miyopia, retinal nerve fiber layer thickness, axial length, spherical equivalent