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Perception of Haidinger Brushes in Macular Disease Depends on Macular Pigment Density and Visual Acuity
摘要： PURPOSE. To optimize the perceptibility of Haidinger brushes (HB) and to investigate its association with visual acuity and macular pigment density. METHODS. In this prospective cross-sectional study, each subject underwent best-corrected visual acuity (BCVA) testing, funduscopy, and assessment of macular pigment optical density (MPOD) using the two-wavelength fundus autofluorescence method. Haidinger brush visibility was tested with a rotating linear polarizer and a controllable three-color light-emitting diode (LED) panel as light source. A simple model of macular pigment absorption was used to predict HB visibility as a function of stimulus wavelength and MPOD. RESULTS. All control eyes (n ? 92) and 34% of the 198 eyes of subjects with macular disease (age-related macular degeneration, n ? 40; macular telangiectasia type 2, n ? 52; Stargardt disease, n ? 58; other retinal dystrophies, n ? 48) perceived HB when an optimized test setup (464-nm LED light) was applied. The degree of psychophysical perception and the dependency on different wavelengths were in accordance with the absorptance model. In eyes of subjects with macular disease, minimum thresholds of MPOD and BCVA required for HB perception were identified. Subjects with macular telangiectasia type 2 showed lowest values of MPOD and were mostly unable to perceive HB despite relatively preserved BCVA. CONCLUSIONS. Macular pigment and a relatively preserved foveal function are necessary for the perception of HB. Haidinger brushes are usually not perceived by subjects with macular telangiectasia type 2, likely due to their characteristic foveal depletion of macular pigment.
关键词： entoptic phenomenon,Haidinger brush,macular pigment,visual acuity,macular disease
更新于2025-09-04 15:30:14
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How light traverses the inverted vertebrate retina
摘要： In our eyes, as in the eyes of all vertebrates, images of the environment are projected onto an inverted retina, where photons must pass through most of the retinal layers before being captured by the light-sensitive cells. Light scattering in these retinal layers must decrease the signal-to-noise ratio of the images and thus interfere with clear vision. Surprisingly however, our eyes display splendid visual abilities. This apparent contradiction could be resolved if intraretinal light scattering were to be minimized by built-in optical elements that facilitate light transmission through the tissue. Indeed, we were able to show that one function of radial glial (Müller) cells is to act as effective optical fibers in the living retina, bypassing the light-scattering structures in front of the light-sensitive cells. Each Müller cell serves as a ‘private’ light cable, providing one individual cone photoreceptor cell with its appropriate pixel of the environmental image, thus optimizing special resolution and visual acuity.
关键词： Photoreceptor cells,Glial cells,Visual acuity,Scattering,Vision
更新于2025-09-04 15:30:14