Subclinical Corneal Edema in Fuchs Dystrophy May Increase Higher Order Aberrations

The presence of subclinical corneal edema in patients with Fuchs endothelial corneal dystrophy results in increased anterior higher order aberrations, according to a study published in Optometry and Vision Science. This condition may lead to larger trefoil II and smaller spherical aberration II measurements in a 4 and 6 mm optic zone, respectively, according to the report. 

Researchers enrolled 56 participants consisting of patients with Fuchs endothelial corneal dystrophy (n=31; eyes, 52; 90.3% women, mean age, 58.90 years) and control group participants (n=35, eyes, 52; 85.3% women; mean age, 59.38 years). Patients with Fuchs dystrophy were stratified according to the presence or absence of subclinical corneal edema (eyes, 33 and 19, respectively). All participants underwent slit lamp examination and corneal topography and aberrometry using a Scheimpflug-Placido disc camera. The team assessed anterior higher order aberrations and expressed them as Zernlike polynomials in both a 4 and 6 mm optic zone.

Individuals with Fuchs dystrophy and corneal edema had larger 4 mm trefoil II and smaller 6 mm spherical aberration II measurements compared with individuals who did not have edema, the report shows. Compared with the control group, 6 mm total higher order aberrations, 6 mm coma, and 4 and 6 mm trefoil aberration measurements were larger among individuals with Fuchs dystrophy (P < .001; P = .006; P = .005, respectively). The 6 mm spherical aberration II, however, was smaller among patients with Fuchs dystrophy(P =.02). 

“We think that when evaluating patients for endothelial keratoplasty in patients with Fuchs’ endothelial corneal dystrophy, the evaluation of corneal aberrations in addition to the presence of subclinical corneal edema will provide information about the expected visual performance,” according to the study authors.

Study limitations include a small sample size, and anterior corneal aberration measurements limited to a 4 and 6 mm optic zone.