Cargando…

Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity

In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptabil...

Descripción completa

Detalles Bibliográficos
Autores principales: Schroth, Volkhard, Joos, Roland, Jaschinski, Wolfgang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592239/
https://www.ncbi.nlm.nih.gov/pubmed/26431525
http://dx.doi.org/10.1371/journal.pone.0138871
_version_ 1782393184635060224
author Schroth, Volkhard
Joos, Roland
Jaschinski, Wolfgang
author_facet Schroth, Volkhard
Joos, Roland
Jaschinski, Wolfgang
author_sort Schroth, Volkhard
collection PubMed
description In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves.
format Online
Article
Text
id pubmed-4592239
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-45922392015-10-09 Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity Schroth, Volkhard Joos, Roland Jaschinski, Wolfgang PLoS One Research Article In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. Public Library of Science 2015-10-02 /pmc/articles/PMC4592239/ /pubmed/26431525 http://dx.doi.org/10.1371/journal.pone.0138871 Text en © 2015 Schroth et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Schroth, Volkhard
Joos, Roland
Jaschinski, Wolfgang
Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title_full Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title_fullStr Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title_full_unstemmed Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title_short Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity
title_sort effects of prism eyeglasses on objective and subjective fixation disparity
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592239/
https://www.ncbi.nlm.nih.gov/pubmed/26431525
http://dx.doi.org/10.1371/journal.pone.0138871
work_keys_str_mv AT schrothvolkhard effectsofprismeyeglassesonobjectiveandsubjectivefixationdisparity
AT joosroland effectsofprismeyeglassesonobjectiveandsubjectivefixationdisparity
AT jaschinskiwolfgang effectsofprismeyeglassesonobjectiveandsubjectivefixationdisparity