Purpose: Oxygen extraction fraction (OEF), defined by the ratio of oxygen consumption to delivery, may be a useful parameter for assessing the retinal tissue status under impaired circulation. We report a method for measurement of inner retinal OEF in rats under normoxia and hypoxia based on vascular oxygen tension (PO(2)) imaging.
Methods: Retinal vascular PO(2) measurements were obtained in 10 rats, using our previously developed optical section phosphorescence lifetime imaging system. Inner retinal OEF was derived from retinal vascular PO(2) measurements based on Fick's principle. Measurements of inner retinal OEF obtained under normoxia were compared between nasal and temporal retinal sectors and repeatability was determined. Inner retinal OEF measurements obtained under normoxia and hypoxia were compared.
Results: Retinal vascular PO(2) and inner retinal OEF measurements were repeatable (ICC ≥ 0.83). Inner retinal OEF measurements at nasal and temporal retinal sectors were correlated (R = 0.71; P = 0.02; n = 10). Under hypoxia, both retinal arterial and venous PO(2) decreased significantly as compared with normoxia (P < 0.001; n = 10). Inner retinal OEF was 0.46 ± 0.13 under normoxia and increased significantly to 0.67 ± 0.16 under hypoxia (mean ± SD; P < 0.001; n = 10).
Conclusions: Inner retinal OEF is a promising quantitative biomarker for the adequacy of oxygen supply for metabolism under physiologically and pathologically altered conditions.
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http://dx.doi.org/10.1167/iovs.12-11305 | DOI Listing |
Photodiagnosis Photodyn Ther
December 2024
Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China, Ministry of Education International Joint Laboratory of Ocular Diseases, Tianjin, China, Tianjin Key Laboratory of Ocular Trauma, Tianjin, China, Tianjin Institute of Eye Health and Eye Diseases, Tianjin, China, China-UK "Belt and Road" Ophthalmology. Electronic address:
Background: This study investigated the association between photoreceptor structural restoration and visual function outcomes in patients undergoing surgery for closed macular holes (MHs). Using adaptive optics scanning laser ophthalmoscopy (AOSLO) and microperimetry, we aimed to provide a more detailed understanding of photoreceptor recovery and visual improvement in closed MHs.
Methods: We conducted a retrospective observational study of 31 eyes of 28 patients who underwent vitrectomy with internal limiting membrane (ILM) peeling to treat idiopathic MHs.
Sci Rep
December 2024
Neurology, Icahn School of Medicine at Mount Sinai, New York, USA.
We used machine learning to investigate the residual visual field (VF) deficits and macula retinal ganglion cell (RGC) thickness loss patterns in recovered optic neuritis (ON). We applied archetypal analysis (AA) to 377 same-day pairings of 10-2 VF and optical coherence tomography (OCT) macula images from 93 ON eyes and 70 normal fellow eyes ≥ 90 days after acute ON. We correlated archetype (AT) weights (total weight = 100%) of VFs and total retinal thickness (TRT), inner retinal thickness (IRT), and macular ganglion cell-inner plexiform layer (GCIPL) thickness.
View Article and Find Full Text PDFDoc Ophthalmol
December 2024
Save Sight Institute Faculty of Medicine and Health, University of Sydney, Sydney, Australia.
Purpose: Multiple mitochondrial syndromes, such as Kearns-Sayre, involve the concurrence of diabetes mellitus and inherited pigmentary retinopathy. It is rare, however, for proliferative disease to develop in these patients as existing inner retinal dysfunction is thought to be protective.
Methods: To our knowledge this is the first description of proliferative diabetic retinopathy (PDR) in Kearns-Sayre syndrome.
Invest Ophthalmol Vis Sci
December 2024
Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States.
Purpose: The retina contains the highest concentration of the omega 3 fatty acid, docosahexaenoic acid (DHA), in the body. Although epidemiologic studies showed an inverse correlation between the consumption of omega 3 fatty acids and the prevalence of diabetic retinopathy, there are no data showing the effect of diabetes on retinal DHA in humans. In this study, we measured the DHA content of the retina in diabetic and non-diabetic humans as well as mice and determined the effect of diabetes on retinal thickness and function in mice.
View Article and Find Full Text PDFIndian J Ophthalmol
December 2024
VST Centre for Glaucoma Care, L V Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
Purpose: To compare the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer thickness, central subfield thickness (CSFT), and parafoveal and perifoveal thickness in children of different age groups with young adult controls by using spectral-domain optical coherence tomography.
Methods: This cross-sectional study included children aged 6-17 years and adult controls (18-22 years) - group 1: 6-9 years (57 eyes), group 2: 10-13 years (116 eyes), group 3: 14-17 years (66 eyes), and group 4 (controls): 18-22 years (61 eyes). A mixed-effects model was used to compare the OCT parameters among the groups, along with multivariable analysis.
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