scholarly journals Near-infrared transillumination imaging combined with aperture photometry for the quantification of melanin in the iris pigment epithelium

PLoS ONE ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. e0230210
Author(s):  
Maciej Czepita
1996 ◽  
Vol 121 (1) ◽  
pp. 100-101
Author(s):  
Paul A. Sidoti ◽  
George Baerveldt ◽  
Marcela Valencia ◽  
Nancy Chen ◽  
Ronald L. Green

2004 ◽  
Vol 45 (12) ◽  
pp. 4520 ◽  
Author(s):  
Hiroshi Itaya ◽  
Vamsi Gullapalli ◽  
Ilene K. Sugino ◽  
Makoto Tamai ◽  
Marco A. Zarbin

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1044
Author(s):  
Magdalena M. Olchawa ◽  
Grzegorz M. Szewczyk ◽  
Andrzej C. Zadlo ◽  
Michal W. Sarna ◽  
Dawid Wnuk ◽  
...  

One of the most prominent age-related changes of retinal pigment epithelium (RPE) is the accumulation of melanolipofuscin granules, which could contribute to oxidative stress in the retina. The purpose of this study was to determine the ability of melanolipofuscin granules from younger and older donors to photogenerate reactive oxygen species, and to examine if natural antioxidants could modify the phototoxic potential of this age pigment. Electron paramagnetic resonance (EPR) oximetry, EPR-spin trapping, and time-resolved detection of near-infrared phosphorescence were employed for measuring photogeneration of superoxide anion and singlet oxygen by melanolipofuscin isolated from younger and older human donors. Phototoxicity mediated by internalized melanolipofuscin granules with and without supplementation with zeaxanthin and α-tocopherol was analyzed in ARPE-19 cells by determining cell survival, oxidation of cellular proteins, organization of the cell cytoskeleton, and the cell specific phagocytic activity. Supplementation with antioxidants reduced aerobic photoreactivity and phototoxicity of melanolipofuscin granules. The effect was particularly noticeable for melanolipofuscin mediated inhibition of the cell phagocytic activity. Antioxidants decreased the extent of melanolipofuscin-dependent oxidation of cellular proteins and disruption of the cell cytoskeleton. Although melanolipofuscin might be involved in chronic phototoxicity of the aging RPE, natural antioxidants could partially ameliorate these harmful effects.


1968 ◽  
Vol 66 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Donald A. Morris ◽  
Paul Henkind

1999 ◽  
Vol 237 (12) ◽  
pp. 1046-1051 ◽  
Author(s):  
G. Thumann ◽  
Norbert Kociok ◽  
Karl Ulrich Bartz-Schmidt ◽  
Peter Esser ◽  
Ulrich Schraermeyer ◽  
...  

2014 ◽  
Vol 19 (7) ◽  
pp. 076007 ◽  
Author(s):  
Natalie Pankova ◽  
Xu Zhao ◽  
Huiyuan Liang ◽  
David Sung Hyeon Baek ◽  
Hai Wang ◽  
...  

2020 ◽  
Vol 1 (1) ◽  
pp. 25-28
Author(s):  
Paolo Brusini ◽  
Veronica Papa

Background: This study was performed to evaluate the use of anterior segment images, obtained with an automatic refractometer, to identify early defects of the iris pigment epithelium in patients with pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) without observable alterations at the slit lamp. Methods: In this cross-sectional observational study, carried out from January 2018 to December 2019, in Policlinico Citta di Udine Health Center, Udine, Italy, we observed anterior segment infrared images of 1700 subjects who were undergoing routine ophthalmological examination using an automatic refractometer. We selected infrared images of subjects who fulfilled the inclusion and exclusion criteria and looked for a focal defect in the iris pigment epithelium. Results: Twenty patients with focal iris pigment epithelial defect were identified and none of them showed evident signs of PDS. After the necessary explanations, they agreed to have further examinations to verify the possibility of PDS. An in-depth evaluation of ocular structures, including gonioscopy, demonstrated the presence of PDS in all subjects with iris defects. Conclusions: The use of infrared images obtained by an automatic refractometer could provide early and easy identification of PDS in crowded ophthalmology clinics or mass screening programs; yet, more well-designed studies are necessary to confirm these preliminary findings and prove this proposed screening tool.


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