A computer-controlled system for measuring dark adaptation and other psychophysical functions

Friedburg, Christoph; Sharpe, Lindsay T.; Beuel, Stefan; Zrenner, Eberhart

doi:10.1007/s004170050039

Cited by 6 publications

(10 citation statements)

References 14 publications

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“…The hybrid adaptive procedure was originally developed in response to the increasing demand for fully automated methods of dark adaptation measurement that could minimise the effects of subjective bias on the data [26]. When the technique was originally described, it was shown to produce lower final threshold estimates than the ascending staircase procedure employed by the Goldmann-Weekers adaptometer [26], a finding that was replicated in the current dataset. However, with regard to the repeatability of cone τ, the hybrid adaptive procedure had no advantage over the other techniques.…”

Section: Assessment Of the Cor Is Important When A Technique Is Evalumentioning

confidence: 70%

“…Dark adaptation functions have often been recorded using custom made dark adaptometers [23][24][25][26][27]. However, several dark adaptometers are now commercially available, including LKC Technologies' SST-1 [28,29] and MacuLogix's AdaptDx [30].…”

Section: Introductionmentioning

confidence: 99%

“…It used an operator controlled 'method of ascending limits' to determine the visual threshold and each threshold measurement was recorded directly onto logarithmic paper [34]. The 'method of ascending limits' has also been implemented in other dark adaptometers, using either simple computer controlled staircases, similar to those used in visual field equipment [9,12,27,30], or adaptive staircases, which estimate threshold by fitting psychometric functions to a series of threshold estimates, in order to minimise redundant presentations and thus to improve the efficiency of testing [26,35].…”

Section: Introductionmentioning

confidence: 99%

“…The computer based methods evaluated were: a hybrid adaptive stimulus presentation combined with a maximum likelihood calculation [26], a modified staircase procedure based on a method previously used with the Humphrey Visual Field Analyser [27] and a novel 10-alternative forced choice procedure. At the outset the hypothesis was that the repeatability of the data obtained using the Goldmann-Weekers adaptometer would be inferior to that obtained using the computer based techniques because operator error would introduce an additional source of variability into threshold measurements.…”

Section: Introductionmentioning

confidence: 99%

“…At the outset the hypothesis was that the repeatability of the data obtained using the Goldmann-Weekers adaptometer would be inferior to that obtained using the computer based techniques because operator error would introduce an additional source of variability into threshold measurements. In addition, it was hypothesised that the estimates of final cone threshold would be lower for the 10-alternative forced choice and hybrid adaptive techniques than for the method of ascending limits because these techniques should provide a genuine estimate of the observer's 5 threshold [26,38]. And finally, that there would be no significant difference in the rate of cone recovery between techniques because cone recovery should be independent of any translation of the data up or down the vertical axis and, to some extent, differences in variability between techniques.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of cone dark adaptation: a comparison of four psychophysical methods

2013

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This is the accepted version of the paper.This version of the publication may differ from the final published version. Methods: Data were obtained from 31 healthy adults on two occasions, using four psychophysical methods. Participants' pupils were dilated and 96% of cone photopigment was bleached before threshold was monitored in the dark using one of the techniques, selected at random. This procedure was repeated for each of the remaining methods. Permanent repository linkAn exponential recovery function was fitted to all threshold recovery data. The coefficient of repeatability (CoR) was calculated to assess the repeatability of the methods and a repeated measures analysis of variance (ANOVA) was used to compare mean recovery parameters.Results: All four methods demonstrated a similar level of inter-session repeatability for measurement of cone recovery, yielding CoRs between 1.18 and 1.56 minutes.There were no statistically significant differences in estimates of mean time constant of cone recovery (cone τ) between the four methods (p = 0.488), however significant differences initial and final cone thresholds were reported (p < 0.005).Conclusions: All of the techniques were capable of monitoring the rapid changes in visual threshold that occur during cone dark adaptation and the repeatability of the techniques was similar. This indicates that, despite the respective advantages and disadvantages of these psychophysical techniques, all four methods would be suitable for measuring cone dark adaptation in clinical practice.

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Section: Assessment Of the Cor Is Important When A Technique Is Evalumentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Measurement of cone dark adaptation: a comparison of four psychophysical methods

2013

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Evaluation of the Night Vision Spectacles on patients with impaired night vision

Friedburg

Sérey

Sharpe

et al. 1999

Graefe's Archive for Clinical and Experimental Ophthalmology

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The repeatability of the Goldmann-Weekers adaptometer for measuring cone adaptation

2011

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To assess the inter-session repeatability of the Goldmann-Weekers adaptometer for the measurement of cone dark adaptation in a population of healthy subjects. Data were obtained from 31 healthy adults (mean age 21.5 ± 2.5) on 2 days. At each visit, pupils were dilated and a 96% bleach of cone photopigment was administered to the test eye before threshold was monitored continuously for 5 min in the dark using the Goldmann-Weekers adaptometer. A single exponential function was fitted to the threshold recovery data on a least squares basis. The coefficient of repeatability (CoR) was calculated to assess the repeatability of the time constant of recovery (τ), initial threshold and final threshold. Cone dark adaptation functions were successfully recorded from all subjects on both visits. The CoR was 79.48 s for τ, 0.71 log cdm(-2) for the initial threshold, and 0.58 log cdm(-2) for the final threshold. Paired samples t-tests showed that there were no significant differences between visits for any of the parameters assesed. Although the Goldmann-Weekers adaptometer was capable of monitoring the rapid changes in threshold that occur during cone dark adaptation, the CoR for τ was relatively large compared to the mean recovery time constants (126.48 ± 40.33 and 119.94 ± 33.25 s at the first and second visits, respectively). This indicates that the Goldmann-Weekers adaptometer is unlikely to be a useful instrument to chart changes in an individual's vision over time.

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A computer-controlled system for measuring dark adaptation and other psychophysical functions

Abstract: The PULS instrument provides an automatic and efficient means of measuring dark adaptation and other psychophysical functions. It determines threshold by a more rigorous and faster method than is conventionally employed in clinical adaptometry.

Cited by 6 publications

References 14 publications

Measurement of cone dark adaptation: a comparison of four psychophysical methods

Measurement of cone dark adaptation: a comparison of four psychophysical methods

Evaluation of the Night Vision Spectacles on patients with impaired night vision

The repeatability of the Goldmann-Weekers adaptometer for measuring cone adaptation

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