Abstract

.) The evaluation of optical quality of the normal and abnormal cornea has been limited principally to measurements of visual performance such as contrast sensitivity, acuity and glare. While these measures reflect aspects of corneal optical quality, they do not readily reflect changes in optical performance as a function of pupil size, nor give insight to the specific cause of the various optical improvements or deficits.
The specific aim of this research is to develop fast, objective measures of corneal optical quality, capable of predicting changes in visual performance for any pupil size of interest. This will be accomplished by calculating the monochromatic wave aberrations of the cornea from the state-of-the-art corneal topography measurements on normal eyes and patients having various corneal conditions which disrupt normal corneal topography. These data will in turn be used to quantify the amount and degree of variation in the higher order aberrations and their influence on the optical transfer function (OTF) of the cornea for normal eyes and eyes with disrupted corneal topography; and predict the resulting changes in the eye's visual performance as a function of pupil size. The ultimate goal of the research is to identify the relationship between altered corneal topography and diminished visual function, thus lessening the adverse consequences of corneal therapies designed to improve the image quality of the eye.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY008520-02
Application #
3265862
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1991-04-01
Project End
1994-03-31
Budget Start
1992-04-01
Budget End
1993-03-31
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost

  Institution

Name
University of Texas Health Science Center San Antonio
Department
Type
Schools of Medicine
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229

  Publications

Hastings, Gareth D; Marsack, Jason D; Nguyen, Lan Chi et al. (2017) Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction? Ophthalmic Physiol Opt 37:317-325
Ticak, Anita; Marsack, Jason D; Koenig, Darren E et al. (2015) A Comparison of Three Methods to Increase Scleral Contact Lens On-Eye Stability. Eye Contact Lens 41:386-90
Marsack, Jason D; Ravikumar, Ayeswarya; Nguyen, Chi et al. (2014) Wavefront-guided scleral lens correction in keratoconus. Optom Vis Sci 91:1221-30
Bradley, Arthur; Xu, Renfeng; Thibos, Larry et al. (2014) Influence of spherical aberration, stimulus spatial frequency, and pupil apodisation on subjective refractions. Ophthalmic Physiol Opt 34:309-20
Shi, Yue; Applegate, Raymond A; Wei, Xin et al. (2013) Registration tolerance of a custom correction to maintain visual acuity. Optom Vis Sci 90:1370-84
Shi, Yue; Queener, Hope M; Marsack, Jason D et al. (2013) Optimizing wavefront-guided corrections for highly aberrated eyes in the presence of registration uncertainty. J Vis 13:
Koenig, Darren E; Nguyen, Lan Chi; Parker, Katrina E et al. (2013) Factors accounting for the 4-year change in acuity in patients between 50 and 80 years. Optom Vis Sci 90:620-7
Ravikumar, Ayeswarya; Marsack, Jason D; Bedell, Harold E et al. (2013) Change in visual acuity is well correlated with change in image-quality metrics for both normal and keratoconic wavefront errors. J Vis 13:28
Ravikumar, Ayeswarya; Sarver, Edwin J; Applegate, Raymond A (2012) Change in visual acuity is highly correlated with change in six image quality metrics independent of wavefront error and/or pupil diameter. J Vis 12:11
He, Lin; Applegate, Raymond A (2011) Predicting crystalline lens fall caused by accommodation from changes in wavefront error. J Cataract Refract Surg 37:1313-22

Showing the most recent 10 out of 53 publications