Abstract
Purpose :
Corneal topography is the most widely used tool for the diagnosis of keratoconus, however, new technologies offer higher resolution and measurements of the three-dimensional cornea to evaluate changes in abnormal corneal thinning. We performed a retrospective, observational study to analyze the difference between central corneal thickness (CCT) and minimum corneal thickness (MCT) in healthy and keratoconus patients by optical coherence tomography (OCT).
Methods :
Medical records of the Cornea and Refractive Surgery Service from the Institute of Ophthalmology at the Zambrano Hellion Medical Center were studied. 22 eyes of 13 keratoconus patients and 28 eyes of 14 healthy corneas were included (14 men and 13 women). Pachymetric evaluation was perfomed using Optovue OCT. CCT and MCT measurements on pachymetry maps were registered and the difference of these values was analyzed with standard deviation for each group of patients.
Results :
The healthy patient average CCT was 543.64 µm (min: 512 µm, max: 588 µm) and average MCT was 537.39 µm (min: 506 µm, max: 580 µm). In keratoconus patients CCT averaged 476.31µm (min: 379 µm, max: 553) and MCT was 435.8 µm (min: 297 µm, max: 494 µm). The average difference between CCT and MCT was 6.25 µm (±1.50 SD) in healthy patients and 40.5 µm (± 31.93 SD) in keratoconus patients. Difference of CCT and MCT was statistically significant (t-test, p value = 5.57 x 105). The most frequent locations for minimum corneal thickness were central and paracentral (31 eyes, 62%).
Conclusions :
CCT and MCT difference analysis in keratoconus patients based on OCT was significantly higher than healthy patients and may be further used as a diagnostic, follow-up or severity criteria tool for an enhanced study of keratoconus pathology.
This is a 2020 ARVO Annual Meeting abstract.