Effect of high myopia on macular thickness
It has been shown in histopathological studies that there is increasing scleral and retinal thinning with myopia. In myopic eyes, the globe is enlarged with an increase in axial length and the stretching beyond normal dimensions may result in thinning of the retina. With the availability of modern imaging technologies, in vivo measurements of retinal thickness have been made possible, and the relationship between myopia and retinal thickness has been examined. The aim is to study the correlation of high myopia with macular thickness by optical coherence tomography (OCT). Sixty patients visiting the outpatient department, Department of Ophthalmology of a tertiary care hospital, were enrolled in the study.

The macular thickness of 30 high myopes and 30 emmetropes was measured using OCT. All high myopes had a spherical equivalent of ≥-6.0 Diopters (D) and intraocular pressure <21 mmHg. All the participants were chosen after excluding other ophthalmic diseases or any history of ocular or refractive surgery. Variables are expressed as mean ± standard deviation. Data analysis was performed using SPSS version 20. Unpaired and Paired t-test was used. The para and perifoveal retinal thickness were significantly thin in high myopic eyes as compared to emmetropic eyes. The central foveal thickness was 298.93 ± 38.813 μm in high myopes and 224.63 ± 16.439 μm in emmetropes, which was statistically significant P < 0.001. The macular thickness was significantly decreased in myopic eyes compared to emmetropic eyes. However, the central foveal thickness was significantly high in high myopes. Therefore, the analysis of macular thickness in the evaluation of macular diseases or glaucoma should be considered based on refractive errors and the location of measurement.