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Frequency-of-seeing curves (psychometric functions) for perimetric stimuli in age-related macular degeneration

Yes / Purpose: Frequency-of-seeing (FoS) curves (psychometric functions) for perimetric stimuli have been widely used in computer simulations of new visual field test
procedures. FoS curves for age-related macular degeneration (AMD) are not available in the literature and are needed for the development of improved microperimetry test procedures, which are of particular interest for use as clinical trial
endpoints.
Methods: Data were refitted from a previous study to generate FoS curves for 20
participants with AMD, each tested at nine locations within the central 10°. Stimulus
parameters, background luminance and dB scale were matched to the MAIA-2 microperimeter, and stimuli were presented in a method of constant stimuli to build
up FoS curves over multiple runs. FoS curves were fitted with a modified cumulative Gaussian function. The relationship between sensitivity and slope of fitted FoS
curves was modelled by robust linear regression, producing models both with and
without an eccentricity parameter.
Results: FoS curves were satisfactorily fitted to data from 174 visual field locations in 20 participants (age 65–83 years, 11 female). Each curve was made up
of a median of 243 (range 177–297) stimulus presentations over a median of 12
(range 9–32) levels. Median sensitivity was 25.5dB (range 3.8–31.4dB). The median
slope (SD of fitted function) was 1.6dB (range 0.5–8.5dB). As in previous studies of
other conditions, the slope of fitted FoS curves increased as sensitivity decreased
(p<0.001).
Conclusions: FoS are provided for participants with AMD, as well as models of the
relationship between sensitivity and slope. These fitted models and data may be
useful for computer simulation studies of microperimetry procedures. Full details
of the fitted curves are provided as supporting information.

Identiferoai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/20035
Date27 September 2024
CreatorsDenniss, Jonathan, Baggaley, H.C., Astle, A.T.
Source SetsBradford Scholars
LanguageEnglish
Detected LanguageEnglish
TypeArticle, Published version
Rights(c) 2025 The Authors. This is an Open Access article distributed under the Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/), CC-BY

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