Pilot Programme for Keratoconus Screening and Management in Adolescents with Down Syndrome.

Background/

Objectives: To screen a group of adolescents with Down Syndrome (Trisomy 21) for keratoconus and assess the feasibility of setting up a national screening service.

Methods: Twenty-seven patients with Down Syndrome between 9 and 18 years of age attended our pilot keratoconus screening clinic. We recorded demographics, medical history, risk factors, best-corrected distance visual acuity, clinical examination results and corneal tomography results. The presence of keratoconus was confirmed by one of three corneal specialists based on clinical and tomographic findings. Tomographic analysis included zonal Kmax, thinnest point, inferior-superior asymmetry (IS Values), Belin/Ambrosio deviation value (BAD-D) and anterior and posterior elevation maps.

Results: Early keratoconus was detected on tomography in 8 out of 54 eyes (15%) at the first review. These eyes were listed for crosslinking. The mean age of diagnosis was 14.6. Corneas in the Down Syndrome screening group were thinner and steeper (mean central corneal thickness (CCT) 479 µm vs. 536 µm and mean Kmax 49.2D vs. 45.8D, respectively) than healthy, age-matched controls from the literature.

Conclusions: Fifteen percent of eyes (5 out of 27 patients) screened had tomographic evidence of keratoconus requiring treatment at their first review. We found an increased incidence of keratoconus in European individuals with Down Syndrome. Screening this vulnerable, high-risk population with corneal tomography can diagnose early keratoconus and enable corneal crosslinking to safely and effectively stabilise the disease. We advocate tomographic keratoconus screening for individuals with Down Syndrome in their mid-teens.