ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose.To study the effect of base curve on subjective comfort of silicone hydrogel extended wear lenses.Methods.Ninety-five subjects were first trial fitted with 8.6-mm base curve lotrafilcon A (Focus Night & Day) lenses and then with 8.4-mm lenses only if poor subjective comfort or poor fit was present. Comfort and fit were assessed after 15 min. Subjects with discomfort or signs of poor fit were then trial fitted with 8.4-mm lenses.Results.Of 190 eyes, 74.2% were fitted with 8.6-mm lenses, and 23.7% required 8.4-mm lenses. Two (2.1%) subjects could not be fitted with either base curve. Mean steep keratometry (K) reading for eyes dispensed with 8.6-mm lenses was 43.88 D and 45.56 D for eyes dispensed in the 8.4-mm lenses (p < 0.001).Conclusions.A clinically useful criterion showing the need for 8.4-mm lenses was steep K of ≥45.50 D; 77% of these eyes required the steeper lens for good comfort and fit. Subjective discomfort with 8.6-mm lenses was also a useful signal for the need of a steeper lens; mean comfort scores for those subjects rose from 6.33 with 8.6-mm lenses to 9.44 with the 8.4-mm lenses for eyes requiring the steeper lens (p < 0.001).

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose.Our previous findings suggest that myopia can be slowed by wearing progressive lenses, and one possible mechanism for this is through the oculomotor system. We reanalyzed our findings to investigate the relationship between baseline oculomotor parameters and change in refraction, and between the change in these values and change in refraction.Methods.Children who wore progressive lenses (N = 38; 26 with +1.50 D addition, and 16 with +2.00 D addition) or single-vision lenses (N = 32) had refraction, distance heterophoria, near heterophoria, and stimulus AC/A ratio measured prospectively over a 2-year period.Results.There were no statistically significant correlations between baseline heterophoria or AC/A values and change in refractive error. Distance and near heterophoria did not change significantly over the 2 years of the experiment; AC/A ratio decreased significantly, but in an equivalent manner for both groups. In the combined progressive lens group, change toward more exophoria at near was associated with less myopia progression. However three-way analysis of variance (visit × lens type × esophoria/nonesophoria) showed significant main effects in refraction over all five visits. There was a significant interaction between lens type and visits; there was no significant interaction between lens type and esophoria/nonesophoria grouping. Three-way analysis of variance showed a statistically significant decrease of AC/A ratio over all five visits; there was no interaction of visit by lens or visit by phoria grouping.Conclusions.Although there were no statistically significant differences between esophoric and nonesophoric subjects, there was only 46% as much myopia progression in the progressive lenses-esophoric group as in the progressive lenses-nonesophoric group. In addition, there were no differences in AC/A ratio between esophoric and nonesophoric subjects. However these findings are not definitive. This experiment was not designed to discriminate between refraction and oculomotor changes in esophoric and nonesophoric subjects and lacked the necessary statistical power to do so.

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Purpose.To evaluate refractive errors in older adults.Methods.The distribution of refractive error components was evaluated in a sample of 569 older adults including 171 participants over the age of 80 years. The mean age was 75.2 years with a range from 59 to 106 years. Emphasis was placed on modern methods of analyzing astigmatic refractive errors, which convert cylindrical refractive errors into primary and oblique components.Results.The known increase in hyperopia after maturity continues into old age. The primary negative astigmatic component increases dramatically in prevalence and amount after age 70 years, whereas the oblique component remains unchanged. Significant anisometropia is common in the oldest old, suggesting failure of emmetropization mechanisms with age. Substantial gender differences exist in refractive changes with age.Conclusions.The continuing changes in all components of refractive error into old age and the surprisingly high prevalence of large amounts of astigmatism and anisometropia emphasize the importance of regular refractive evaluations among the oldest old.

ISSN:1040-5488    

出版商:OVID    

年代:2002

数据来源: OVID