Association Of Scheimpflug Characteristics, Severity Of Guttae And Impact On Higher Order Aberrations And Visual Acuity In Fuchs Corneal Dystrophy

To use Scheimpflug imaging as a tool for studying tomographic characteristics and to associate the changes with specular cell counts, severity of guttae and their impact on higher order aberrations and visual acuity in eyes with Fuchs Corneal dystrophy.

Wagh Eye Clinics

This was a prospective observational study involving 20 controls and 20 cases with Fuchs Corneal Dystrophy fulfilling inclusion and exclusion criteria. They underwent visual acuity testing followed by clinical grading using Modified Krachmer Scale, Scheimpflug imaging evaluating tomographic characteristics like loss of parallel isopachs, displacement of thinnest location, posterior depression and higher order aberrations and specular microscopy to study endothelial cell counts, severity of guttata, hexagonality and coefficient of variation.

Patients with Advanced FECD had an average visual acuity of 0.33±0.17 log mar units, corresponding to a mean specular count of 1786±344 and a guttata severity grade 2 or above. The 3 specific tomographic features were all present in all FECD corneas with clinically definite edema (n=10), 2 or more signs were present in 50% of FECD corneas (n=5) suspicious of subclinical edema and 50% of corneas (n=5) showed neither tomographic nor clinical signs of edema. Total anterior corneal HOAs were increased in moderate (0.54±0.23) and advanced FECD (0.60±0.72microns) compared with controls (0.46±0.27 microns). Total posterior corneal HOAs were increased in moderate (2.11±1.15), and advanced (2.05±2.09) FECD compared with controls (0.99±0.37microns).

Anterior and posterior corneal HOAs are higher than normal even in early stages of FECD. Subclinical corneal edema in FECD can be detected by Scheimpflug tomography establishing its role as an ancilliary tool to aid diagnosis and prognostication.