A new study conducted in New Zealand has revealed keratoconus is prevalent in 30% to 38% of people with Down syndrome, suggesting that screening may be worthwhile for people with the genetic disorder.
The cross-sectional study performed by optometrists and ophthalmologists within the University of Auckland’s Faculty of Medical and Health Sciences screened 110 athletes with Down syndrome who attended the 2017 New Zealand Special Olympics National Summer Games. It was the first study of its kind in Australasia.
With keratoconus known to disproportionately affect people with Down syndrome, they wanted to investigate its prevalence, with the findings published in RANZCO’s official journal Clinical and Experimental Ophthalmology recently.
The researchers used corneal topography to identify keratoconus and adopted two independent quantitative criteria. The first was keratoconus severity index ≥ 30%. The second, adapted from the literature, required at least four of eight topographic parameters to be abnormal.
According to the study, data from the worst eye were analysed. Diagnosis in each group was subsequently confirmed by three corneal fellowship‐trained ophthalmologists. Those with a definitive diagnosis were grouped into Keratoconus Confirmed Group 1 (KCC1) and Keratoconus Confirmed Group 2 (KCC2), respectively.
Using only topographic data, keratoconus was identified in 39.8% of athletes by quantitative topographic criteria one, and in 64.3% athletes by criteria two.
Keratoconus was then confirmed by qualitative sub‐specialist review in 30.6% (KCC1) and 38.8% (KCC2) athletes, respectively. The mean keratometry in groups KCC1 and KCC2 were 48.4 ± 3.2D and 48.2 ± 2.9D, respectively. Most were male and of European ethnicity.
“We report keratoconus in 30.6% to 38.8% of athletes with Down syndrome; therefore, we believe keratoconus screening is indicated in Down syndrome for early management,” the researchers stated.