ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Purpose.To conduct a preliminary investigation on the ability of the Melbourne Low Vision ADL Index to detect changes in functional ability as a result of low-vision rehabilitation.Methods.Twenty two subjects with age-related macular degeneration (ARMD) who were newly referred to the Kooyong Low Vision Clinic were recruited. The Melbourne Low Vision ADL Index was administered prerehabilitation and postrehabilitation. Changes in scores and effect size statistics were analyzed.Results.The median total score for the subjects prerehabilitation was 67, and the median total score postrehabilitation was 76. The difference in prerehabilitation and postrehabilitation scores was statistically significant (Wilcoxon signed rank test = 248.5, p < 0.001). The mean change score for the total Melbourne Low Vision ADL Index was 9.3 (SD, 5.6). Thus the overall effect size statistic (mean change score divided by SD of prerehabilitation score) was 0.78.Conclusions.This preliminary investigation indicates that the Melbourne Low Vision ADL Index is responsive to a rehabilitation program for patients with ARMD. It has potential to be used as a measure of low-vision rehabilitation outcomes.

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Purpose.To determine why the reading addition increases after the age of 55 to 60 years when accommodation is zero.Methods.Distance and near visual acuities, arm length, habitual near working distance, reading addition, and pupil diameter were measured in 44 subjects aged >60 years (mean, 72.9 ± 5.7). Reading addition values were attained using three techniques: least-plus addition using both N-notation text and MN-READ text and the cross-cylinder technique.Results.The mean dioptric working distance was 2.75 ± 0.40 D. The reading addition found using N-notation text (+2.21 ± 0.38 D) was significantly lower than that measured using MN-READ text (+2.48 ± 0.49 D) or the cross-cylinder method (+2.53 ± 0.44 D). The reading addition was positively correlated with the dioptric working distance (r = 0.47, p < 0.01), and decreasing habitual working distance was associated with poorer visual acuity (r = −0.42, p < 0.01).Conclusions.Our results suggest that decreases in near visual acuity after 60 years of age lead to a reduction in habitual working distance, which increases text angular subtense. In turn, the reduced working distance requires a greater reading addition. Increases in depth of field associated with both suprathreshold text (N-notation) and lower visual acuity lead to reading additions being less than the dioptric working distance.

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Background.It is important for both researchers and clinicians to know the spectral composition of the light that reaches the retina. With this in mind, Johnson et al. developed a quick, objective instrument called the Lens Absorption Monitor (LAM) to measure the attenuation of light by the ocular media. Using a more refined method of measuring and correcting for scatter, we compared the results of the LAM against those with a subjective method utilizing a bipartite scotopic brightness-matching procedure (BIP).Methods.We tested 41 healthy subjects (mean age, 35.9 years) with the LAM and BIP.Results.Intereye correlation coefficients for the LAM were 0.70 at 410 nm and 0.83 at both 430 and 450 nm; for BIP, intereye correlation coefficients were 0.56 at 410 nm, 0.42 at 430 nm, and 0.38 at 450 nm. For optical density as a function of age, there was no statistically significant difference between the two instruments at 410 nm in either the slope (p > 0.43) or y intercept (p > 0.75). However, at both 430 and 450 nm, there was a significant difference in both slope (p < 0.001) and y intercept (p < 0.05) for the two instruments.Conclusions.With the latest refinements, LAM density measures correlated well with BIP estimates at 410 nm, but not at 430 or 450 nm. This underscores the fact that the LAM measures the spectral density of the anterior segment, whereas the BIP method is a measure of all the ocular media except for macular pigment. The difference between these two measures is consistent with the existence of a prereceptoral, presumably intraretinal, pigment (or pigments) located outside the anatomic fovea that absorbs light at short wavelengths.

ISSN:1040-5488    

出版商:OVID    

年代:2001

数据来源: OVID