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Visual performance after correcting higher order aberrations in keratoconic eyes
Ramkumar Sabesan1, Geunyoung Yoon
1Institute of Optics, University of Rochester, Rochester, NY, USA. ramkumar@optics.rochester.edu
Journal of Vision
|September 18, 2009
Summary
Adaptive optics corrected vision in keratoconic eyes, but the visual benefit was limited. Long-term adaptation to poor image quality may restrict gains from higher order aberration correction.
Area of Science:
- Ophthalmology
- Optical Engineering
- Vision Science
Background:
- Keratoconic eyes exhibit irregular optical blur due to significant higher order aberrations (HOAs).
- Standard optical theory predicts improved vision with aberration correction, but adaptation to poor image quality may limit this benefit in keratoconus.
Purpose of the Study:
- To investigate the visual benefit of adaptive optics (AO) correction in keratoconic eyes.
- To determine if long-term adaptation to HOAs impacts the achievable visual acuity after correction.
Main Methods:
- An adaptive optics (AO) system with a deformable mirror and Shack-Hartmann sensor was used.
- High contrast tumbling E visual acuity (HCVA) was measured in 8 keratoconic and 8 normal eyes.
- Aberrations were dynamically corrected in a closed-loop system with a residual error of ~0.1 microm.
Main Results:
- AO correction significantly improved HCVA in keratoconic eyes (logMAR -0.07) compared to uncorrected vision, but less than in normal eyes (logMAR -0.26).
- In normal eyes, AO-corrected HCVA showed no correlation with native HOA magnitudes.
- In keratoconic eyes, higher native HOA magnitudes correlated with poorer AO-corrected HCVA (R² = 0.67).
Conclusions:
- While AO correction improves visual acuity in keratoconus, the potential visual benefit may be restricted.
- Long-term exposure to poor retinal image quality in keratoconus might lead to neural adaptations that limit immediate visual gains from aberration correction.
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