Abstract
Purpose :
To identify the average spectacle correction of patients with keratoconus (KC).
Methods :
985 eyes of 695 patients diagnosed with KC were stratified into three groups: the entire cohort, eyes with a maximum keratometry (Kmax) >55D, and eyes with a maximum keratometry (Kmax)≤55D. Eyes with previous corneal surgery were excluded from this study. Manifest sphere, manifest cylinder, and the manifest refraction spherical equivalent (MRSE) were measured with the Snellen eye chart, and a standard phoropter at 20 feet. These measurements were recorded and analyzed.
Results :
Of the 985 eyes, 595 (60%) had a Kmax>55D and 390 (40%) had a Kmax≤55D. The average age of the entire cohort was 33.4±11.3, and was 34.4±12.1 and 31.0±10.5 in the Kmax≤55D and Kmax>55D groups, respectively. This difference in age was statistically significant (p<0.001). The manifest sphere was -2.3D±4.5D, -2.8D±5.1D, and -1.4D±3.2D in the entire cohort, Kmax>55D, and Kmax≤55D groups, respectively. The average manifest cylinder was -3.6D±2.2D, -4.1D±2.4D, and -2.9D±1.7D in the entire cohort, Kmax>55D, and Kmax≤55D groups, respectively. The average MRSE was -3.9D±4.6D, -4.8D±5.1D, and -2.8D±3.2D in the entire cohort, Kmax>55D, and Kmax≤55D groups, respectively. All of the differences in refractions between the Kmax>55D and Kmax≤55D were statistically significant (p<0.001). A myopic MRSE was recorded in 86.0%, 85.7%, and 86.4% of patients, in the entire cohort, Kmax>55D, and Kmax≤55D groups, respectively.
Conclusions :
Most KC patients have a myopic MRSE. On average, KC patients with more severe disease have more myopic refractions, and more astigmatic correction as well.
This is a 2020 ARVO Annual Meeting abstract.