摘要:

Purpose.We evaluated the performance of the RK4 (reverse-geometry) contact lens in patients with flat central and steep peripheral corneal topography after penetrating keratoplasty (PK).Methods.A retrospective study was performed of post-PK patients fitted with RK4 lenses on the Cornea Service at Wills Eye Hospital, between March 2000 and February 2002.ResultsFifteen eyes of 13 post-PK patients were fitted with RK4 lenses and monitored for more than two months (range, 2.1–23.5 months; mean, 8.1 ± 7.0 months). The average number of lens refits per eye was 1.0 ± 1.2 (range, 0–4). Ninety-three percent (14/15) of the eyes that were fitted achieved at least 20/30 visual acuity, and 53% (8/15) of eyes achieved 20/20 visual acuity. A comparison of prefitted and post-fitted corrected visual acuity demonstrated a statistically significant improvement (P<0.01). RK4 lenses were successfully worn full time or part time in all cases.Conclusions.The RK4 lens can provide well-tolerated visual correction in cases with central flat, peripheral steep corneal contour following PK.

ISSN:1542-2321    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose.To investigate the effects of daily wear opaquely tinted hydrogel soft contact lenses on contrast sensitivity functions, as measured using the Pelli-Robson chart viewed at 1 meter.Methods.Contrast sensitivity was measured in 48 healthy individuals before and 6 hours after soft contact lens wear. Twenty-four subjects used clear soft contact lenses and 24 used tinted soft contact lenses.Results.The contrast sensitivity scores were significantly decreased monocularly and binocularly (P= 0.000 andP= 0.002, respectively) in the colored contact lens group whereas there were no significant changes in the clear contact lens group (P= 0.317 andP= 0.317, respectively).Conclusions.Color-tinted contact lenses were associated with a reduction of contrast sensitivity function. Therefore, those who wear colored contact lenses should be informed about the possible consequences of tinted contact lens wearing.

ISSN:1542-2321    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose.This article reports clinical results comparing a high-oxygen permeable (HDk) silicone hydrogel soft contact lens with a low-oxygen permeable (LDk) soft hydroxyethyl methacrylate contact lens when worn on an extended-wear basis.Methods.Six practitioners in France enrolled 134 subjects in this 4-month, open-label, multicenter, prospective, randomized, cross-over study. Subjects were randomized to receive either an HDk lotrafilcon A or an LDk etafilcon A soft contact lens. Subjects crossed over to the alternative lens after either 3 months’ experience with the HDk lens or 1 month’s experience with the LDk lens. Clinical and subjective data were collected at scheduled follow-up visits.Results.The subjective data has been reported in a separate article. Both types of lenses gave similar performance for visual acuity. Biomicroscopic examination findings averaged below grade 1 (trace) for both lenses throughout the study. A statistically significant difference for limbal redness was found at 1 week (HDk = 0.11; LDk = 0.33; paired-ttest,P<0.05). Eight of 10 biomicroscopic signs improved within 1 week when subjects changed from the LDk lens to the HDk lens. Deposits for both lenses remained below grade 1, and wetting was nearly perfect for both lenses throughout the study. Over 90% of fittings for both lenses were acceptable or optimal.Conclusions.The improvements in biomicroscopy signs seen with the HDk lens may provide practitioners an alternative to LDk contact lenses for extended wear.

ISSN:1542-2321    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose.This article reports the subjective results of a study comparing extended-wear high-oxygen permeable (HDk) silicone hydrogel soft contact lenses with low-oxygen permeable (LDk) hydroxyethyl methacrylate lenses.Methods.Six practitioners in France enrolled 134 subjects in this 4-month, open-label, multicenter, prospective, randomized, cross-over study. Subjects were randomized to receive prescriptions of either an HDk lotrafilcon A or an LDk etafilcon A soft contact lens. Subjects then crossed over to the alternative lens after either 3 months’ experience with the HDk lens or 1 month’s experience with the LDk lens. Clinical and subjective data were collected at scheduled follow-up visits.Results.The clinical data has been reported in a separate article. After 1 month of wear, HDk lenses were rated better than LDk lenses for all aspects of comfort and overall average symptoms. Subjects were satisfied with both lenses, and lens features were comparable through 1 month. The preference was higher for HDk lenses after crossing over, either from or to LDk lenses. Eighty-six percent of HDk and 85% of LDk subjects reported wearing their lenses while sleeping for 7 nights per week during the study. Seventy-seven percent of HDk and 21% of LDk subjects reported wearing their lenses while sleeping for 22 to 31 nights during the study.Conclusions.Based on subjective results, therefore, the HDk lens offers another option to patients and practitioners for extended-wear or continuous-wear soft contact lenses.

ISSN:1542-2321    

出版商:OVID    

年代:2003

数据来源: OVID