Incidence and risk factors of glaucoma after surgery for congenital cataract diagnosed under one year of age: Protocol for Korean Nationwide Epidemiological Study for Childhood Glaucoma (KoNEC)

Nationwide Incidence of Infantile Cataract Surgery and Risk of Secondary Glaucoma in a Population-based Birth Cohort

PURPOSE

To determine the nationwide birth cohort incidence of infantile cataract (IC) surgery and the risk of secondary glaucoma in a Korean population.

DESIGN

A population-based, retrospective cohort study.

METHODS

We accessed the Korean National Health Claims database to identify patients with IC who were diagnosed before 1 year of age and who underwent IC surgery among all Koreans born between 2008 and 2018 (n = 9,593,003). We estimated IC surgery incidence in a birth cohort. The incidence rates of post-IC surgery glaucoma were estimated per 100 person-years, based on the Poisson distribution. The risk factors for post-IC surgery glaucoma, including ophthalmic and systemic comorbidities, were analyzed by multivariable logistic regression analysis.

RESULTS

During the 11-year study period, 692 patients underwent IC surgery. The annual birth cohort incidence of IC surgery in the general population ranged from 5.10 to 9.29 cases per 100,000 individuals. Among patients who had been followed up for longer than 1 year (n = 650), 92 (14.2%) developed glaucoma, and its incidence rate was 2.29 (95% confidence interval, 1.86-2.80) per 100 person-years. The mean time from IC surgery to glaucoma development was 4.7 ± 3.5 years. No factors were identified as being associated with post-IC surgery glaucoma risk other than primary or secondary intraocular lens implantation, which reduces the risk (all P < .05). In patients without primary intraocular lens implantation, the risk of glaucoma increased steeply during the first 2 years after IC surgery.

CONCLUSION

This study identified the birth cohort incidence of IC surgery and secondary glaucoma risk in individuals of East Asian ethnicity. These estimates may help to better understand the epidemiologic features and clinical courses of patients with IC.