A One Year Hospital Based Cross Sectional Study Of The Association Between The Pattern Of Myopic Fundal Changes And The Axis Of Astigmatism Of The Eye

Abstract

Purpose of the study: The study was conducted as a cross sectional study to assess the correlation, if any, between the pattern of myopic fundal changes and the axis of astigmatism and to find an etiopathogenic association in the occurrence of myopic fundal changes. Methods: A total of 97 eyes of 64 patients having myopic disc changes, i.e., peripapillary atrophy or myopic crescents were studied. Each eye had undergone subjective refraction testing, measurement of corneal curvature, axial length and anterior chamber depth using A – Scan Biometer (Echorule2, Biomedix). Fundoscopic examination was carried out thoroughly by indirect ophthalmoscopy with +20 D lens. The fundus photograph was recorded with a Canon CF–1 Digital Retina Camera. The deep/longest axis of the crescent/peripapillary atrophy was determined and the axis of myopic crescent or peripapillary atrophy was measured using the annotations incorporated within the software attached to the fundus camera and was ascribed a value in degrees, in a manner similar to the axis of astigmatism in refraction. The long axis of peripapillary changes and of the disc crescent were correlated with the axis of astigmatism in patients with compound myopic astigmatism and the coefficient of correlation determined. Results: A statistically significant correlation was found between the axis of myopic astigmatism and the long axis of the myopic retinal degeneration (crescent or peripapillary atrophy). According to Spearman’s rank correlation co-efficient, p< 0.001 which was considered significant. Conclusion: A positive correlation is present between the axis of astigmatism of the eye and of the angle of the myopic fundal changes. Astigmatism may have an aetiopathogenic association in the occurrence of myopic fundal changes.