Show simple item record

dc.contributor.authorBham, H.A.
dc.contributor.authorDewsbery, S.D.
dc.contributor.authorDenniss, Jonathan
dc.date.accessioned2020-07-27T13:20:24Z
dc.date.available2020-07-27T13:20:24Z
dc.date.issued2020-07
dc.identifier.citationBham HA, Dewsbery SD and Denniss J (2020) Unaltered perception of suprathreshold contrast in early glaucoma despite sensitivity loss. Investigative Ophthalmology & Visual Science. 61(8): 23.en_US
dc.identifier.urihttp://hdl.handle.net/10454/17921
dc.descriptionYesen_US
dc.description.abstractPURPOSE. Glaucoma raises contrast detection thresholds, but our natural visual environment is dominated by high contrast that may remain suprathreshold in early to moderate glaucoma. This study investigates the effect of glaucoma on the apparent contrast of visible stimuli. METHODS. Twenty participants with glaucoma with partial visual field defects (mean age, 72 ± 7 years) and 20 age-similar healthy controls (mean age, 70 ± 7 years) took part. Contrast detection thresholds for Gabor stimuli (SD, 0.75°) of four spatial frequencies (0.5, 1.0, 2.0, and 4.0 c/deg) were first measured at 10° eccentricity, both within and outside of visual field defects for participants with glaucoma. Subsequently, the contrast of a central Gabor was matched to that of a peripheral Gabor with contrast fixed at two times or four times the detection threshold. Data were analyzed by linear mixed modelling. RESULTS. Compared with controls, detection thresholds for participants with glaucoma were raised by 0.05 ± 0.025 (Michelson units, ± SE; P = 0.12) and by 0.141 ± 0.026 (P < 0.001) outside and within visual field defects, respectively. For reference stimuli at two times the detection contrast, matched contrast ratios (matched/reference contrast) were 0.16 ± 0.039 (P < 0.001) higher outside compared with within visual field defects in participants with glaucoma. Matched contrast ratios within visual field defects were similar to controls (mean 0.033 ± 0.066 lower; P = 0.87). For reference stimuli at four times the detection contrast, matched contrast ratios were similar across all three groups (P = 0.58). Spatial frequency had a minimal effect on matched contrast ratios. CONCLUSIONS. Despite decreased contrast sensitivity, people with glaucoma perceive the contrast of visible suprathreshold stimuli similarly to healthy controls. These results suggest possible compensation for sensitivity loss in the visual system.en_US
dc.description.sponsorshipSupported by a College of Optometrists PhD Scholarship.en_US
dc.language.isoenen_US
dc.relation.isreferencedbyhttps://doi.org/10.1167/iovs.61.8.23en_US
dc.rightsCopyright 2020 The Authors. This work is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).en_US
dc.subjectGlaucomaen_US
dc.subjectContrast perceptionen_US
dc.subjectContrast matchingen_US
dc.subjectContrast constancyen_US
dc.subjectSuprathresholden_US
dc.titleUnaltered perception of suprathreshold contrast in early glaucoma despite sensitivity lossen_US
dc.status.refereedYesen_US
dc.date.Accepted2020-06-01
dc.date.application2020-07-17
dc.typeArticleen_US
dc.type.versionPublished versionen_US
refterms.dateFOA2020-07-27T13:20:42Z


Item file(s)

Thumbnail
Name:
Denniss_iovs_Final.pdf
Size:
831.1Kb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record