Primary congenital glaucoma in Denmark, 1977-2016.

Purpose: To perform an epidemiological survey of all patients in Denmark diagnosed with primary congenital glaucoma (PCG) from 1977 to 2016.

Methods: A retrospective, nationwide study based on a review of medical files of all children with PCG born in Denmark from 1977 to 2016. PCG was defined as glaucoma due to isolated angle dysgenesis affecting children from birth and including late onset/late recognized PCG, excluding glaucoma associated with other congenital abnormalities. Incidence and risk factors of PCG including gender, consanguinity, family history, ethnicity, comorbidity and prematurity were evaluated and stratified by decade (1977-1986, 1987-1996, 1997-2006 and 2007-2016). Age at first symptoms, age at diagnosis, age at time of first surgery and possible diagnostic delay were assessed.

Results: Of 118 patients were identified, annual incidence of PCG was 4.8 per 100 000 live born. 62.3% of cases were bilateral. The relative risk (RR) of PCG was significantly higher in boys (62.7% of patients, RR 1.60 (95% CI 1.10-2.32)). 13.6% had comorbidity. Median age at time of first symptoms was 75 days, median age at time of diagnosis was 150 days and median diagnostic delay was 75 days with no significant difference throughout the decades. Unilateral cases presented symptoms and were diagnosed significantly later than bilateral cases.

Conclusion: We provide unique nation-based information on the incidence of PCG from a single country covering 40 years. Male gender was a risk factor. Diagnostic delay was unchanged throughout the 4 decades and a high percentage of comorbidity was revealed. Introducing a standardized paediatric screening of all PCG children should be considered.