Dehydration, lens movement and dryness ratings of hydrogel contact lenses

Pritchard, Nicola & Fonn, Desmond (1995) Dehydration, lens movement and dryness ratings of hydrogel contact lenses. Ophthalmic & Physiological Optics: The Journal of the British College of Ophthalmic Opticians, 15(4), pp. 281-286.

View at publisher


Previous studies have shown that soft lenses dehydrate during lens wear. The purpose of this study was to determine the dehydration time course of 38% water content non-ionic Medalist, 58% ionic Acuvue and 74% non-ionic Permaflex lenses, and the relationship between dehydration and in vivo diameter, movement and symptoms of dryness. Nineteen subjects randomly wore three pairs of lenses, each for 7 h. Lens movement and diameter were measured in vivo and hydration after lens removal at 1, 3 and 7 h. Dryness was rated by the subjects using a visual analogue scale. A separate experiment was conducted to measure hydration changes after 7 continuous hours of lens wear. The water content of all three lens types decreased significantly over 7 h with Acuvue decreasing more than the Permaflex and Medalist lenses in the interrupted and continuous experiments (ANOVA P < 0.05). Dehydration of Acuvue was significantly greater in the 7 h continuous experiment (9.0 +/- 2.6% H2O, ANOVA P = 0.0062) compared to the interrupted experiment. Hydration levels measured for Acuvue lenses on subjects for control purposes at 0, 1, 3 and 7 h showed no difference over time (ANOVA P = 0.0711). Movement of Permaflex lenses decreased 0.60 +/- 0.57 mm (ANOVA P = 0.0005) over 7 h and the in vivo diameter of Acuvue lenses decreased by 0.12 +/- 0.16 mm (ANOVA P = 0.0569). Dryness ratings increased significantly and equally for all three lenses over 7 h (ANOVA P = 0.9833).(ABSTRACT TRUNCATED AT 250 WORDS)

Impact and interest:

63 citations in Scopus
48 citations in Web of Science®
Search Google Scholar™

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 20566
Item Type: Journal Article
Refereed: Yes
Additional Information: Accession Number: 7667020 Language: English. Date Revised: 20061115. Date Created: 19951006. Date Completed: 19951006. Update Code: 20081217. Publication Type: Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't. Journal ID: 8208839. Publication Model: Print. Cited Medium: Print
Keywords: contact lenses, hydrophilic, adult, desiccation, female, male, time factors, water analysis, xerophthalmia etiology
DOI: 10.1046/j.1475-1313.1995.9500004w.x
ISSN: 0275-5408
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)
Divisions: Current > Institutes > Institute of Health and Biomedical Innovation
Copyright Owner: Copyright 1995 Wiley
Deposited On: 20 May 2009 22:31
Last Modified: 10 Aug 2011 14:08

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page