Document Detail


The parameter stability of a high dk rigid lens material.
MedLine Citation:
PMID:  16303399     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Abstract/OtherAbstract:
The use of rigid materials with high oxygen permeability (Dk) is on the increase, their major benefit being the reduction of hypoxia. However, there is a reluctance to use these materials possibly due to increased surface scratching, reduced wettability, increased deposition, reduced life expectancy and parameter instability. Considering parameter stability, various studies have demonstrated contradictory results or used high Dk materials based on the silicone acrylate polymer. This study was designed to investigate whether the parameters of a high Dk rigid fluorocarbon contact lens material changed during daily wear and extended wear schedules. Thirty five subjects, divided into group groups, Group I wore the lens on a daily wear basis, whereas those in Group II wore the lens on a monthly extended wear basis. The parameters and integrity of the lenses were monitored in both groups every 3 months. For lens integrity a statistically significant increase in surface scratching was demonstrated for the lenses worn by the subjects of both groups over the time of the study (Group I, F=7.990, P <0.0001 [ANCOVA]; Group II, F=6.241, P=0.003 [ANCOVA]). The only parameter to show a statistically significant variation over the study period was that of centre thickness for the lenses worn by the subjects in Group I (F=3.976, P=0.0063 [ANCOVA]), with a mean reduction in centre thickness of 0.022 mm at the 12 month visit. No change was noted for either group or between groups for the other parameters measured. This study demonstrates that the parameters of rigid contact lenses manufactured from high Dk fluorocarbons are stable with only a non-clinically significant reduction in centre thickness for the contact lenses worn by the subjects in Group I.
Authors:
C Woods; N Efron
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Contact lens & anterior eye : the journal of the British Contact Lens Association     Volume:  22     ISSN:  1367-0484     ISO Abbreviation:  Cont Lens Anterior Eye     Publication Date:  1999  
Date Detail:
Created Date:  2005-11-23     Completed Date:  2006-01-17     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9712714     Medline TA:  Cont Lens Anterior Eye     Country:  England    
Other Details:
Languages:  eng     Pagination:  14-8     Citation Subset:  -    
Affiliation:
Eurolens Research, Dept of Optometry and Vision Sciences, UMIST, Manchester.
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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