Abstract
Purpose :
To determine if patients who develop contact-lens-related corneal infiltrative events (CIE) or microbial keratitis have a corneal sagittal depth that is less than the population mean.
Methods :
Contact lens wearers (N=19) with a documented CIE or microbial keratitis within the last two years were recruited. Corneal sagittal depth was calculated from topography (central simulated keratometry, eccentricity, 12 mm diameter) for comparison with published, population means (N = 18,387 eyes; mean ± SD = 2.74 ± 0.15 mm) using one-sample t-tests. Sagittal depth was also measured from anterior segment optical coherence tomography (OCT) images using a 12 mm chord, for validation purposes. Differences between the topography-calculated and OCT-measured sagittal depth were determined with Bland-Altman analyses.
Results :
Participants were mostly young (mean ± SD age = 27.8 ± 11.0 years, range 18 to 65 years); predominantly female (16 of 19); experienced, spherical (13 of 19), soft contact lens wearers. Topography-calculated sagittal depth was slightly larger than, but highly correlated with, OCT image measurements for a 12 mm chord (mean of the differences ± SD = 0.15 ±0.09 mm, t = 7.3, p < 0.0001; r = 0.78, p < 0.0001). The mean ± SD sagittal depth for participants (2.65 ± 0.13 mm) was significantly less than the population mean (t = −2.8, p = 0.01).
Conclusions :
Contact lens wearers with adverse events had a corneal sagittal depth that was significantly shallower than the population mean. These data suggest that one-size-fits-most soft contact lenses may have a sagittal depth that is too deep for patients with a shallower-than-typical corneal sagittal depth, which could increase adverse event risk. Future studies should evaluate the relative risk of corneal sagittal depth compared to other known risk factors, and also determine clinical guidelines for fitting soft contact lenses based on sagittal depth measurement.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.