A study conducted in Spain has determined that patients with Down syndrome have posterior surface keratometry values similar to those observed in patients with mild keratoconus. The posterior corneal surface of patients with Down syndrome is steeper, more irregular and shows more higher-order aberrations (HOAs) as well as reduced volume and thinner pachymetry than patients with healthy corneas.

The researchers analyzed the posterior surface characteristics of 37 patients with Down syndrome and compared them with a group of 40 patients with normal corneas and 46 patients who suffer from mild keratoconus. Patients with Down syndrome, when compared with healthy controls, have a steeper mean keratometry of 7mm and more irregular posterior corneal surface, with HOAs of 1.07 vs. 0.15 in healthy controls. They also have coma-like of 0.88 vs. 0.13 in controls and thinnest pachymetry of 497.68 vs. 538.95 in controls.

At the same time, no statistically significant difference was found between patients with Down syndrome and patients with mild keratoconus in keratometry, HOAs, coma-like and pachymetry.

The researchers believe their results suggest practitioners must closely examine patients with Down syndrome to rule out the presence of a specific corneal alteration and establish an early therapeutic approach to avoid possible corneal blindness. They advocate for developing future perspectives and lines of research, including the genetic analysis of a possible chromosomal alteration in common between patients with Down syndrome and keratoconus. Doing so will help determine the possible presence of a specific keratopathy in this group of patients.

Vega Estrada A, Fariselli C, Alio JL. Posterior corneal features in patients with Down syndrome and their relation with keratoconus. Br J Ophthalmol. March 2, 2020. [Epub ahead of print].