학술논문
Investigating the linkage between mesopic spatial summation and variations in retinal ganglion cell density across the central visual field.
Document Type
Academic Journal
Author
Hunter AML; Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK.; Anderson RS; Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK.; National Institute for Health Research (NIHR) Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and University College London Institute of Ophthalmology, London, UK.; Redmond T; School of Optometry & Vision Sciences, Cardiff University, Cardiff, UK.; Garway-Heath DF; National Institute for Health Research (NIHR) Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and University College London Institute of Ophthalmology, London, UK.; Mulholland PJ; Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK.; National Institute for Health Research (NIHR) Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and University College London Institute of Ophthalmology, London, UK.
Source
Publisher: Blackwell Publishers Country of Publication: England NLM ID: 8208839 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1475-1313 (Electronic) Linking ISSN: 02755408 NLM ISO Abbreviation: Ophthalmic Physiol Opt Subsets: MEDLINE
Subject
Language
English
Abstract
Purpose: The relationship between perimetric stimulus area and Ricco's area (RA) determines measured thresholds and the sensitivity of perimetry to retinal disease. The nature of this relationship, in addition to effect of retinal ganglion cell (RGC) number on this, is currently unknown for the adaptation conditions of mesopic microperimetry. In this study, achromatic mesopic spatial summation was measured across the central visual field to estimate RA with the number of RGCs underlying RA also being established.
Methods: Achromatic luminance thresholds were measured for six incremental spot stimuli (0.009-2.07 deg2 ) and 190.4 ms duration, at four locations, each at 2.5°, 5° and 10° eccentricity in five healthy observers (mean age 61.4 years) under mesopic conditions (background 1.58 cd/m 2 ). RA was estimated using two-phase regression analysis with the number of RGCs underlying RA being calculated using normative histological RGC counts.
Results: Ricco's area exhibited a small but statistically insignificant increase between 2.5° and 10° eccentricity. Compared with photopic conditions, RA was larger, with the difference between RA and the Goldmann III stimulus (0.43°) being minimised. RGC number underlying RA was also higher than reported for photopic conditions (median 70 cells, IQR 36-93), with no significant difference being observed across test locations.
Conclusions: Ricco's area and the number of RGCs underlying RA do not vary significantly across the central visual field in mesopic conditions. However, RA is larger and more similar to the standard perimetric Goldmann III stimulus under mesopic compared with photopic adaptation conditions. Further work is required to determine if compensatory enlargements in RA occur in age-related macular degeneration, to establish the optimal stimulus parameters for AMD-specific microperimetry.
(© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)
Methods: Achromatic luminance thresholds were measured for six incremental spot stimuli (0.009-2.07 deg
Results: Ricco's area exhibited a small but statistically insignificant increase between 2.5° and 10° eccentricity. Compared with photopic conditions, RA was larger, with the difference between RA and the Goldmann III stimulus (0.43°) being minimised. RGC number underlying RA was also higher than reported for photopic conditions (median 70 cells, IQR 36-93), with no significant difference being observed across test locations.
Conclusions: Ricco's area and the number of RGCs underlying RA do not vary significantly across the central visual field in mesopic conditions. However, RA is larger and more similar to the standard perimetric Goldmann III stimulus under mesopic compared with photopic adaptation conditions. Further work is required to determine if compensatory enlargements in RA occur in age-related macular degeneration, to establish the optimal stimulus parameters for AMD-specific microperimetry.
(© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)