Risk factors analysis of age-related macular degeneration in Tibetan of plateau area and establishment of nomogram prediction model

Objective

To determine the prevalence and risk factors for age-related macular degeneration (AMD) in Tibetan of plateau area, and to establish a nomogram prediction model.

Methods

A cross-sectional study was carried out.The 40-year-old and older Tibetan subjects were enrolled by cluster random sampling from Xinghai County and Tongde County with an average altitude of 3 000 meters in Qinghai Province.Questionnaire survey, routine ophthalmic examinations, direct fundus photography and health education were carried out among the subjects.The questionnaire items included age, gender, smoking, drinking, living duration in plateau region, daily sunshine duration, diabetes, hypertension and hyperlipidemia.A χ² test was used to screen significantly factors, and risk factors for AMD were analyzed by logistic regression analysis.The nomogram plot was drawn by R software to establish a predicting model.The study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Qinghai Provincial People’s Hospital (No.2017-21). Written informed consent was obtained from each subject prior to any medical examination.

Results

A total of 1 223 subjects were enrolled, and AMD were detected in 190 subjects with an prevalence of 15.54%.The risk factors for AMD were old age, living duration in plateau region, sunshine duration, smoking, hypertension and hyperlipidemia.Age was the first one of risk factors for AMD (OR: 20.183, 95%CI: 9.536-29.805, P<0.001), followed by sunshine duration (OR: 3.785, 95% CI: 1.581-8.721, P<0.001). The nomogram prediction model showed that when the questionnaire score was >150, the probability of suffering AMD was 50%.The decision curve showed that when the threshold probability was >25%, the predicted probability of AMD was the same as the actual probability.

Conclusions

Pathogesis of AMD in Tibet is associated with old age, living duration in plateau area, sunshine duration, smoking, hypertension and hyperlipidemia.

Macular degeneration, age-related; Prevalence; Risk factors; Plateau area; Nomo score