June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
APPLYING MEASURED LEVELS OF RIGID LENS HORMS REDUCTION TO A LARGE, SIMULATED SAMPLE OF KERATOCONIC WAVEFRONT ERRORS
Author Affiliations & Notes
  • Jason D Marsack
    Optometry, University of Houston, Houston, Texas, United States
  • Gareth D Hastings
    Optometry, University of Houston, Houston, Texas, United States
  • Roxana T Hemmati
    Optometry, University of Houston, Houston, Texas, United States
  • Lan C Nguyen
    Optometry, University of Houston, Houston, Texas, United States
  • Jos Rozema
    Ophthalmology, Antwerp University Hospital, Antwerp, Belgium
    Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
  • Raymond A Applegate
    Optometry, University of Houston, Houston, Texas, United States
  • Footnotes
    Commercial Relationships   Jason Marsack, University of Houston (P); Gareth Hastings, None; Roxana Hemmati, None; Lan Nguyen, None; Jos Rozema, None; Raymond Applegate, University of Houston (P)
  • Footnotes
    Support  NIH EY019105
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 1279. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Jason D Marsack, Gareth D Hastings, Roxana T Hemmati, Lan C Nguyen, Jos Rozema, Raymond A Applegate; APPLYING MEASURED LEVELS OF RIGID LENS HORMS REDUCTION TO A LARGE, SIMULATED SAMPLE OF KERATOCONIC WAVEFRONT ERRORS. Invest. Ophthalmol. Vis. Sci. 2017;58(8):1279.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : The mainstay of correction for the highly aberrated eye is the rigid (corneal, scleral, hybrid) contact lens, which serves to mask a percentage of the higher order aberration (HOA) originating from the anterior corneal surface. The purpose of this study was to apply the percentage of higher order root mean square (HORMS) reduction observed in a sample of eyes during scleral contact lens wear to a large, simulated population of eyes with keratoconus (KC) and compare the remaining level of uncorrected HORMS to levels seen in the normal population.

Methods : Wavefront aberration data were quantified over a 5mm pupil from eight highly aberrated eyes of four subjects under two conditions: 1) uncorrected and 2) in the presence of a spherical scleral contact lens correction (sSCL). An average % reduction in HORMS with the sSCL was calculated for the 3rd and 4th radial orders, as well as for total higher order RMS. A population of 1000 aberration structures simulating 5mm keratoconus wavefront error were produced using a statistical wavefront model. To generalize the efficacy of typical rigid lens corrections to the larger population of individuals with keratoconus, the average reduction in HORMS was then applied to the 1000 simulated aberration structures.

Results : The average reduction in total HORMS during sSCL wear was 65% ± 13%, similar to levels observed in the literature for rigid lens wearing post-surgical eyes. When examined by order, levels of reduction were 68% ± 12% for the 3rd order and 53% ± 28% for the 4th order. Of the 1000 simulated eyes, only 0.3% fell within the normal range of (HORMS < 0.342um) when evaluated uncorrected. When typical levels of HORMS reduction were applied, this number increased to 21.9%. The level of masking needed to ensure correction of 95% of the simulated sample to typical levels of HORMS is 90%.

Conclusions : Passive correction reduces HOA in the 3rd and 4th orders. When the efficacy of rigid lenses is applied to the larger population of simulated KC eyes, there is a segment that will continue to suffer from elevated levels of higher order aberration. It is hypothesized that those with the most to gain from personalized, wavefront-guided contact lens corrections will originate from this group.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×