The visual pigments in the compound eye of the comma butterfly, Polygonia c-album, were investigated in a specially designed epi-illumination microspectrophotometer. Absorption changes due to photochemical conversions of the visual pigments, or due to light-independent visual pigment decay and regeneration, were studied by measuring the eye shine, i.e., the light reflected from the tapetum located in each ommatidium proximal to the visual pigment-bearing rhabdom. The obtained absorbance difference spectra demonstrated the dominant presence of a green visual pigment. The rhodopsin and its metarhodopsin have absorption peak wavelengths at 532 nm and 492 nm, respectively. The metarhodopsin is removed from the rhabdom with a time constant of 15 min and the rhodopsin is regenerated with a time constant of 59 min (room temperature). A UV rhodopsin with metarhodopsin absorbing maximally at 467 nm was revealed, and evidence for a blue rhodopsin was obtained indirectly.
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http://dx.doi.org/10.1007/s00359-005-0608-x | DOI Listing |
Am J Ophthalmol
January 2025
Centre for Public Health, Faculty of Medicine and Health Sciences, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom. Electronic address:
Purpose: Color imaging is the accepted reference standard for detection of macular fibrosis in neovascular age-macular degeneration. Other imaging modalities of fluorescein angiography (FA) and spectral domain optical coherence tomography (SD-OCT) are also used but no formal agreement studies exist. We evaluated the agreement between fibrosis on colour, FA and SD-OCT-detected hyperreflective material (HRM) and their clinical relevance.
View Article and Find Full Text PDFPreviously we reported color matches measured in young adults using a newly developed multi-wavelength LED-based visual trichromator with which we estimated their individual L-, M- and S-cone spectral sensitivities. Here, we extend those measurements to include 70 additional observers aged between 8 to 80 years. As in our previous work, a series of color matching measurements were made to a reference white.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
To assess retinal pigment epithelium (RPE) tears in eyes which underwent pars plana vitrectomy (PPV) for submacular hemorrhage (SMH) secondary to age-related macular degeneration and to investigate the prognostic factors of visual outcomes. This study was a retrospective, observational case series that included 24 eyes of 24 patients who underwent PPV with subretinal tissue plasminogen activator and air for SMH. RPE tears were investigated using spectral-domain or swept-source optical coherence tomography images with raster scan, combined confocal scanning laser ophthalmoscope near-infrared images and color fundus photographs.
View Article and Find Full Text PDFCell Death Dis
January 2025
Laboratory of Developmental Cell Biology and Disease, State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
Epithelial-to-mesenchymal transition (EMT) is a critical and complex process involved in normal embryonic development, tissue regeneration, and tumor progression. It also contributes to retinal diseases, such as age-related macular degeneration (AMD) and proliferative vitreoretinopathy (PVR). Although absent in melanoma 2 (AIM2) has been linked to inflammatory disorders, autoimmune diseases, and cancers, its role in the EMT of the retinal pigment epithelium (RPE-EMT) and retinal diseases remains unclear.
View Article and Find Full Text PDFCurr Top Dev Biol
January 2025
Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States. Electronic address:
Animals perceiving light through visual pigments have evolved pathways for absorbing, transporting, and metabolizing the precursors essential for synthesis of their retinylidene chromophores. Over the past decades, our understanding of this metabolism has grown significantly. Through genetic manipulation, researchers gained insights into the metabolic complexity of the pathways mediating the flow of chromophore precursors throughout the body, and their enrichment within the eyes.
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