Abstract
Purpose :
Many highly aberrated eyes, such as those with keratoconus, continue to experience reduced visual performance and optical quality with traditional ophthalmic corrections. This study aims to compare 1) high contrast visual acuity (VA), 2) letter contrast sensitivity (CS) (4, 8, and 16 cycles per degree (cpd)), 3) reduction in higher-order aberrations (HORMS), and 4) improvement in the visual image quality metric logVSX, after adaptation, through 3 corrections: the habitual correction, a best conventional scleral lens (SL), and an individualized wavefront-guided (WFG) scleral lens in highly-aberrated eyes.
Methods :
Conventional scleral lenses as well as WFG scleral lenses with custom aberration correction up to the 5th radial order were fit for 16 eyes of 8 subjects; 2 subjects habitually wore rigid contact lenses, 5 wore spectacles, and 1 was habitually unaided; per CLEK severity 7 were mild, 8 moderate, and 1 severe. VA (mean of 3 logMAR charts), CS (mean of 3 measures per spatial frequency), and wavefront error (WFE) (mean of 3 measures) were recorded monocularly with each correction. HORMS and VSX were calculated from WFE measures. All data were collected after wearing the respective correction for ~8 weeks.
Results :
Mean (±SD) logMAR VA across eyes improved from habitual (+0.12 ±0.19) to SL (–0.03 ±0.08) to WFG lens (–0.08 ±0.11). Six eyes improved by >3 lines from their habitual with a WFG lens. Habitual rigid lens wearers improved by >1 line with a WFG lens.
Area under the CS curve increased from habitual (10.74 ±3.75) to SL (13.98 ±2.36) to WFG lens (15.71 ±2.51). At 4, 8, and 16 cpd most eyes improved CS from habitual to SL, and improved further with a WFG lens.
Mean HORMS for a 5 mm pupil reduced from habitual (0.94 ±0.64) to SL (0.47 ±0.25) to WFG lens (0.27 ±0.08), and logVSX improved from habitual (–1.56 ±0.50) to SL (–1.33 ±0.52) to WFG (–0.96 ±0.22).
Most eyes reached normal levels of VA, CS, and HORMS with WFG lenses.
Conclusions :
In many highly aberrated eyes, custom WFG scleral lens corrections better compensated for HORMS, provided superior visual image quality, and ultimately resulted in better visual performance than conventional scleral lenses. These comparisons will inform as to which eyes might function acceptably with conventional scleral lenses and which should benefit most from tailored WFG corrections. Recruitment and data collection are on-going.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.