Machine Learning Models for Predicting Long-Term Visual Acuity in Highly Myopic Eyes

Abstract

Importance: High myopia is a global concern due to its escalating prevalence and the potential risk of severe visual impairment caused by pathologic myopia. Using artificial intelligence to estimate future visual acuity (VA) could help clinicians to identify and monitor patients with a high risk of vision reduction in advance.

Objective: To develop machine learning models to predict VA at 3 and 5 years in patients with high myopia.

Design, setting, and participants: This retrospective, single-center, cohort study was performed on patients whose best-corrected VA (BCVA) at 3 and 5 years was known. The ophthalmic examinations of these patients were performed between October 2011 and May 2021. Thirty-four variables, including general information, basic ophthalmic information, and categories of myopic maculopathy based on fundus and optical coherence tomography images, were collected from the medical records for analysis.

Main outcomes and measures: Regression models were developed to predict BCVA at 3 and 5 years, and a binary classification model was developed to predict the risk of developing visual impairment at 5 years. The performance of models was evaluated by discrimination metrics, calibration belts, and decision curve analysis. The importance of relative variables was assessed by explainable artificial intelligence techniques.

Results: A total of 1616 eyes from 967 patients (mean [SD] age, 58.5 [14.0] years; 678 female [70.1%]) were included in this analysis. Findings showed that support vector machines presented the best prediction of BCVA at 3 years (R2 = 0.682; 95% CI, 0.625-0.733) and random forest at 5 years (R2 = 0.660; 95% CI, 0.604-0.710). To predict the risk of visual impairment at 5 years, logistic regression presented the best performance (area under the receiver operating characteristic curve = 0.870; 95% CI, 0.816-0.912). The baseline BCVA (logMAR odds ratio [OR], 0.298; 95% CI, 0.235-0.378; P < .001), prior myopic macular neovascularization (OR, 3.290; 95% CI, 2.209-4.899; P < .001), age (OR, 1.578; 95% CI, 1.227-2.028; P < .001), and category 4 myopic maculopathy (OR, 4.899; 95% CI, 1.431-16.769; P = .01) were the 4 most important predicting variables and associated with increased risk of visual impairment at 5 years.

Conclusions and relevance: Study results suggest that developing models for accurate prediction of the long-term VA for highly myopic eyes based on clinical and imaging information is feasible. Such models could be used for the clinical assessments of future visual acuity.

Figure 1.. Flowchart Showing an Overview of the Machine Learning Approach

AUPRC indicates area under the precision-recall curve; AUROC, area under the receiver operating characteristic curve; BCVA, best-corrected visual acuity; DCA, decision curve analysis; LASSO, least absolute shrinkage and selection operator; MAE, mean absolute error; MICE, multiple imputation by chained equations; OCT, optical coherence tomography; RMSE, root mean square error; SMOTE, synthetic minority oversampling technique. ^aVariables of interest included general information, basic ophthalmic information, and features from fundus and OCT images. ^bData preprocessing included the removal of zero-variance variables, data imputation (MICE), data normalization, and variable selection (LASSO). ^cData preprocessing included data imputation (MICE) and data normalization. ^dData preprocessing included the removal of zero-variance variables, data imputation (MICE) data normalization, deal imbalanced data (SMOTE), and collinearity analysis.

Figure 2.. Model Diagnostics for the Logistic Regression Model Based on the Original Data Set Predicting the Risk of Visual Impairment in 5 Years

A, Receiver operating characteristic (ROC) curve. B, Area under the precision-recall (PR) curve. C, Confusion matrix. AUPRC indicates area under the PR curve; AUROC, area under the ROC curve.

Figure 3.. Nomogram for Predicting the Probability of the Risk of Visual Impairment in 5 Years

Abbreviations: BCVA, best-corrected visual acuity; MNV, myopic macular neovascularization; MTM, myopic traction maculopathy; PM, pathologic myopia.