Development Of A Prognostic Model For Predicting Long-Term Visual Acuity After Cataract Surgery In Children With Bilateral Congenital Cataracts: A Single Center Retrospective, Observational Study

To evaluate the factors affecting best corrected visual acuity (BCVA) in pediatric patients with bilateral congenital cataracts (CC) after cataract extraction and intraocular lens (IOL) implantation, and to develop a robust model for predicting long-term visual acuity.

This is a single center retrospective, observational study.

This retrospective study followed 194 pediatric patients with bilateral CC between January 2008 and December 2021. Endpoint event was defined as the final BCVA less than 0.22 Log MAR, which was considered as good outcome at the last follow-up. The probability of endpoint event was modelled using Cox proportional hazards regression and subsequently internally validated by 200 times 5-fold cross validation. In the prognostic model, h0(t) represents the baseline risk equation could be any non-negative equation for time (t), and  h(t) represents the probability of the time of endpoint event occurring at time (t) without any endpoint event occurring before time (t).

A long-term visual acuity prognostic model for bilateral CC after surgical treatment was established, ln h(t)=-0.009×age at cataract extraction-0.015×age at IOL implantation-2.934×without nystagmus +ln h0(t) ,and visualized for clinical practice by nomogram and contour plot. The model exhibited reasonably accurate discrimination with AUROC 0.712 (95%CI 0.589-0.835) and C-index 0.797 (95%CI 0.683-0.911). According to the model, children with bilateral CC undergoing cataract extraction before 6-month old (HR 1.80, 95%CI 0.92-3.70), implanting IOL before 31-month old (HR 3.70, 95%CI 1.77-7.80) and without nystagmus at last follow-up (HR 11.20, 95%CI 3.96-31.80) would have higher probability to achieve good outcome (BCVA <0.22 Log MAR). 

The long-term visual acuity prognostic model exhibits adequate performance for individualized prediction and is helpful for clinical practice. The risk stratification index is considered to guide the timing of surgery.