Evaluation of the Relationship Between Age-related Macular Degeneration and Refractive Error, Socio-demographic Features, and Biochemical Variables in a Turkish Population

Abstract

Objectives: To investigate the relationship between age-related macular degeneration (AMD) and refractive error and axial length, as well as the socio-demographic characteristics and biochemical variables that may affect this relationship. Materials and Methods: A total of 196 eyes of 98 patients over 50 years of age who were diagnosed with AMD at our clinic were included in this cross-sectional study. Early and late AMD findings were categorized according to the age-related eye disease study grading scale. Objective refractive error was measured by autorefractometer, confirmed by subjective examination, and spherical equivalent was calculated. Refractive errors of -0.50 D to 0.50 D were classified as emmetropia, 0.50 D as hyperopia. Axial length was measured by ultrasonic biometry and values ≤23.00 mm were classified as short, >23.00 and <24.00 mm as normal, and ≥24.00 mm as long axial length. Demographic, systemic, and biochemical parameters of all patients were also investigated. Results: Hypermetropic refractive error and shorter axial length were significantly more common than the other groups (p<0.01). No differences were observed between early and late stage groups in terms of refractive error and axial length. Patients with myopia had significantly lower values for total cholesterol, triglyceride, fasting blood glucose, and proportion of smokers. Rates of oral nutritional supplement use and fish consumption were significantly higher in the early AMD group. The most common comorbidity among the AMD patients in our study was essential hypertension. Conclusion: Hyperopic refractive error and shorter axial length were found to be associated with AMD. Longitudinal studies including larger patient numbers are needed to elucidate the causal and temporal relationship between hyperopic refractive error and AMD.

Keywords

• Axial length
• refractive error
• risk factors
• age related macular degeneration