Background: Myopia is the most common error of refraction and, in many countries; complications related to high myopia are a major cause of blindness. The prevalence of myopia has been reported as high as 70–90% in some Asian countries, 30–40% in Europe and the United States, and 10–20% in Africa. Myopia, which is measured in diopters, has also been classified by degree. Low myopia usually describes myopia of −3.00 diopters or less. Medium myopia usually describes myopia between −3.00 and −6.00 diopters. High myopia usually describes myopia of −6.00 or more. Roughly 30% of myopes have high myopia.
Aim of the Work: To correlate macular thickness in the different degrees of axial myopia.
Subjects and Methods: Cross sectional study assessing 40 myopic eyes of 22 subjects. They were subdivided according to axial length into two groups: Group A (low myopes) 20 myopic eyes with their axial length between 24-26.5mm.Group B (high myopes) 20 myopic eyes with their axial length above 26.5mm. Cases were selected from the outpatient clinic of the Al-Azhar University Hospitals. All were above eighteen years of age. Each patient was subjected to a full clinical examination, refraction, axial length assessment by IOL master and macular thickness determined by Swept source OCT.
Results: The study revealed a highly significant negative correlation between axial length and macular thickness in all quadrants except foveal thickness which is non-significant positive correlation (an increase in thickness with increasing axial length). Macular thickness was significantly less in high myopes than low myopes except in the fovea. The spherical equivalent was significantly negatively correlated with increasing axial length.
Conclusion: In this study macular thickness in myopes was correlated with axial length. A significant negative correlation was found between increasing axial length and macular thickness in all quadrants of the macula except for the fovea. As the degree of myopia increased the average overall thickness of the macula decreased. No significant correlation was found between the foveal thickness and axial length.