Taner Ozgurtas1, Sercan Tekin2, Fatih Yesildal3, Umut Karaca4, Fevzi Nuri Aydin5, Muhammed Talha Ugurlu2, Mehmet Ozler6, Hakan Durukan7. 1. Department of Medical Biochemistry, Gulhane Military Medical Academy, Ankara 06010, Turkey. 2. School of Medicine, Gulhane Military Medical Academy, Ankara 06010, Turkey. 3. Department of Medical Biochemistry, Diyarbakir Military Hospital, Diyarbakir 21100, Turkey. 4. Department of Ophthalmology, Isparta Military Hospital, Isparta 32040, Turkey. 5. Department of Biochemistry, Sirnak Military Hospital, Sirnak 73000, Turkey. 6. Department of Physiology, Gulhane Military Medical Academy, Ankara 06010, Turkey. 7. Department of Ophthalmology, Gulhane Military Medical Academy, Ankara 06010, Turkey.
Abstract
AIM: To examine changes in retinal vasculature after treatment with different oxygen concentrations from common retinopathy of prematurity (ROP) models and to determine a novel and practical ROP model. METHODS: A sample of 14 newborn Sprague-Dawley rats was used. The study group (n=7) was exposed to 95% oxygen for 4h per day followed by normoxic laboratory conditions for 20h. This cycle was repeated for 14d. The control group (n=7) was subjected to normobaric normoxic conditions. On postnatal day 14 (P14), the two groups were placed in room air for 7d. On P21, the two groups were examined using indirect ophthalmoscopy. All eyes were enucleated for immunofluorescence (IF) staining of the vasculature of retinas and analysis of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 alpha (HIF-1α), placental growth factor (PLGF) in vitreous humor, and then the rats were sacrificed by decapitation. All procedures were repeated using another litter of 14 pups. RESULTS: In the study group and under normobaric hyperoxic conditions, retinal neovascularization and peripheral avascular retina were determined in 85% of the rats through indirect ophthalmoscopic examination. Also IF staining of retina of the study group showed retarded peripheral vascular growth. The difference between the two groups for VEGF, HIF-1α and PLGF concentrations of vitreous humor was statistically significant (P=0.003, 0.007, 0.027 respectively). CONCLUSION: Fluctuating oxygen concentrations are primarily responsible for retinal neovascularization. Our new ROP model is practical and applicable for all retinal neovascularization studies, considering the laboratory procedures.
AIM: To examine changes in retinal vasculature after treatment with different oxygen concentrations from common retinopathy of prematurity (ROP) models and to determine a novel and practical ROP model. METHODS: A sample of 14 newborn Sprague-Dawley rats was used. The study group (n=7) was exposed to 95% oxygen for 4h per day followed by normoxic laboratory conditions for 20h. This cycle was repeated for 14d. The control group (n=7) was subjected to normobaric normoxic conditions. On postnatal day 14 (P14), the two groups were placed in room air for 7d. On P21, the two groups were examined using indirect ophthalmoscopy. All eyes were enucleated for immunofluorescence (IF) staining of the vasculature of retinas and analysis of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 alpha (HIF-1α), placental growth factor (PLGF) in vitreous humor, and then the rats were sacrificed by decapitation. All procedures were repeated using another litter of 14 pups. RESULTS: In the study group and under normobaric hyperoxic conditions, retinal neovascularization and peripheral avascular retina were determined in 85% of the rats through indirect ophthalmoscopic examination. Also IF staining of retina of the study group showed retarded peripheral vascular growth. The difference between the two groups for VEGF, HIF-1α and PLGF concentrations of vitreous humor was statistically significant (P=0.003, 0.007, 0.027 respectively). CONCLUSION: Fluctuating oxygen concentrations are primarily responsible for retinal neovascularization. Our new ROP model is practical and applicable for all retinal neovascularization studies, considering the laboratory procedures.
Authors: L E Smith; E Wesolowski; A McLellan; S K Kostyk; R D'Amato; R Sullivan; P A D'Amore Journal: Invest Ophthalmol Vis Sci Date: 1994-01 Impact factor: 4.799
Authors: Merline Benny; Diana R Hernandez; Mayank Sharma; Keyvan Yousefi; Shathiyah Kulandavelu; Sunil Batlahally; Ronald Zambrano; Pingping Chen; Eliana C Martinez; Augusto F Schmidt; Lina A Shehadeh; Roberto I Vasquez-Padron; Shu Wu; Omaida C Velazquez; Karen C Young Journal: Physiol Rep Date: 2020-01
Authors: Akiyoshi Uemura; Marcus Fruttiger; Patricia A D'Amore; Sandro De Falco; Antonia M Joussen; Florian Sennlaub; Lynne R Brunck; Kristian T Johnson; George N Lambrou; Kay D Rittenhouse; Thomas Langmann Journal: Prog Retin Eye Res Date: 2021-02-25 Impact factor: 21.198