Open AccessTwo-Photon Microperimetry: A Media Opacity-Independent Retinal Function Assay
Author(s) -
Ang Wei,
Urmi Mehta,
Grażyna Palczewska,
Anton M. Palma,
Vincent M. Hussey,
Luke Hoffmann,
Anna Diep,
Kevin Nguyen,
Bryan Le,
Steven Yone-Shun Chang,
Andrew Browne
Publication year - 2021
Publication title -
translational vision science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 21
ISSN - 2164-2591
DOI - 10.1167/tvst.10.2.11
Subject(s) - microperimetry , retinal , opacity , ophthalmology , optometry , function (biology) , medicine , optics , biology , physics , microbiology and biotechnology
Purpose Compare results obtained using infrared two-photon microperimetry (2PM-IR) with conventional visual function tests in healthy subjects of varying ages with and without simulated media opacities. Methods Subjects from two separate cohort studies completed cone contrast threshold (CCT) testing, conventional microperimetr y , visible light microperimetry from a novel device (2PM-Vis), and infrared two-photon microperimetry. The first cohort study, which consisted of six healthy volunteers (23 to 29 years of age), evaluated the effects of simulated media opacities on visual performance testing. Subjects underwent testing on four visual function devices nine separate times under the following conditions: no filter, red filter, green filter, blue filter, light brown filter, dark brown filter, polarized black filter (0° rotation), and polarized black filter (90° rotation). Subjects subsequently performed 2PM-IR and 2PM-Vis testing without a filter in the mydriatic state. The second cohort study evaluated the effect of age on visual test performance in 42 healthy subjects split between two groups (ages 20–40 years and 60–80 years). Results Retinal sensitivity measured by 2PM-IR demonstrated lower variability than all other devices relying on visible spectrum stimuli. Retinal sensitivity decreased proportionally with the transmittance of light through each filter. CCT scores and retinal sensitivity decreased with age in all testing modalities. Visible spectrum testing modalities demonstrated larger test result differences between young and old patient cohorts; this difference was inversely proportional to the wavelength of the visual function test. Conclusions 2PM-IR mitigates media opacities that may mask small differences in retinal sensitivity when tested with conventional visual function testing devices. Translational Relevance Conventional visual function tests that emit visible light may not detect differences in retinal function during the early stages of age-related diseases due to the confounding effects of cataracts. Infrared light, which has greater transmittance through ocular tissue, may reliably quantify retinal sensitivity and thereby detect degenerative changes early on.