Role of Axial Length and Corneal Radius of Curvature Ratio in Determination of Refractive Status of Eye in North-West Indian Population

Abstract

Introduction: The prevalence of refractive error defects has been extensible studied in several geographical areas on different ethnic population, because the eye anatomy varies so the effect of different ethnicity results in slight variation in different average parameters. This study is undertaken to know the corelation between axial length, corneal curvature and refractive state of eye in North-West Indian population. Materials and Methods: The present study is a cross-sectional observational study and was carried out in the department of Anatomy and a private eye hospital of the north western Indian region. study group consists of 78 male and 72 female subjects between the age group of 18 to 70 years. The axial length was measured through A-scan ultrasound and Nikon NRK 501 refractometer was used for taking the measurement of corneal radius of curvature. The AL/ CR ratio calculated and subjects were categorized into three groups- Emmetropes, Hypermetropes and Myopes according to measured refractive status. Statistical Analysis: The pearson correlation analysis was performed using SPSS software. A p-value < 0.05 was considered statistically significant. Results: The Mean axial length (AL) and corneal radius of curvature (CL) found to be 23.453 ± 0.88 mm 7.79 ± 0.22 mm respectively. AL/CR ratio found as 3.01 ± 0.17; Strong inverse correlation of axial length and corneal radius of curvature ratio (AL/CR) was found with refractive state in males (r= -0.980) and females (r= -0.984).Conclusion: Study reports significant correlation between AL/CR ratio and refractive state of the eye. Thus, findings support the AL/CR ratio as a better index for categorizing the refractive status of an individual than axial length alone.