Comparison of Flat and Steep Rigid Contact Lens Fitting Methods in Keratoconus
Autor: | Karen Steger-May, Timothy B. Edrington, Timothy T. McMahon, Karla Zadnik, Joseph T. Barr, Mae O. Gordon |
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Rok vydání: | 2005 |
Předmět: |
Keratoconus
medicine.medical_specialty Time Factors Visual acuity genetic structures Contact Lenses Rigid contact lens Eye disease Visual Acuity Cornea Prosthesis Fitting Ophthalmology medicine Humans Corneal Scar Retrospective Studies business.industry Equipment Design Odds ratio medicine.disease eye diseases Confidence interval Contact lens Cross-Sectional Studies Treatment Outcome sense organs medicine.symptom business Follow-Up Studies Optometry |
Zdroj: | Optometry and Vision Science. 82:1014-1021 |
ISSN: | 1040-5488 |
DOI: | 10.1097/01.opx.0000192349.11525.de |
Popis: | Purpose. The purpose of this article is to compare the safety and efficacy of flat- and steep-fitting rigid contact lenses in keratoconus. Methods. The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a 16-center observational study. Cross-sectional results at baseline were generated for 1091 subjects with longitudinal results from the 871 subjects who completed 8 years of follow up. Results. Of the 761 rigid contact lens-wearing patients at baseline, 41% had a scar at baseline compared with 24% of the nonrigid contact lens wearers (odds ratio (OR), 2.15; 95% confidence interval (CI), 1.35-3.43; p 0.001). Eighty-seven percent were fitted with flat-fitting lenses, whereas 13% were fitted with steep-fitting lenses. Rigid lens fitting method was also associated with incident corneal scarring. A greater proportion of the corneas wearing flat-fitting contact lenses were scarred (43% compared with 26% for the steep-fitted eyes; OR, 2.19; 95% CI, 1.37-3.51; p 0.001). After controlling for corneal curvature, the association of rigid contact lens fit and corneal scarring at baseline did not persist (adjusted OR, 1.20; 95% CI, 0.70-2.06; p 0.52). Thirty-two percent of unscarred eyes at baseline fitted flat had developed an incident corneal scar by the eighth year follow-up visit compared with 14% of eyes fitted steep (OR, 2.93; 95% CI, 1.34-6.42; p 0.007). Conclusions. The data reported here indicate that, after controlling for disease severity in the form of corneal curvature, keratoconic eyes fitted with a rigid contact lens resulting in an apical touch fluorescein pattern did not have an increased risk of being scarred centrally at baseline. This "natural history" sample cannot determine causal proof that one method of fitting lenses is safer than another. To achieve this, a randomized clinical trial is needed. (Optom Vis Sci 2005;82:1014-1021) |
Databáze: | OpenAIRE |
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