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Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model.
Exp Eye Res. 2006 Feb; 82(2):219-28.EE

Abstract

Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains. IOP was raised in one eye of Wistar (N = 5) and Brown-Norway(B-N)(N = 7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N = 7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined. Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones. The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP-stressed RGCs. Identification and enhancement of such factors could prove useful for glaucoma therapy.

Authors+Show Affiliations

Department of Ophthalmology, Mt Sinai School of Medicine, Box 1183, 1 Gustave L Levy Place, New York, NY 10029, USA. john.danias@mssm.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16109406

Citation

Danias, John, et al. "Characterization of Retinal Damage in the Episcleral Vein Cauterization Rat Glaucoma Model." Experimental Eye Research, vol. 82, no. 2, 2006, pp. 219-28.
Danias J, Shen F, Kavalarakis M, et al. Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model. Exp Eye Res. 2006;82(2):219-28.
Danias, J., Shen, F., Kavalarakis, M., Chen, B., Goldblum, D., Lee, K., Zamora, M. F., Su, Y., Brodie, S. E., Podos, S. M., & Mittag, T. (2006). Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model. Experimental Eye Research, 82(2), 219-28.
Danias J, et al. Characterization of Retinal Damage in the Episcleral Vein Cauterization Rat Glaucoma Model. Exp Eye Res. 2006;82(2):219-28. PubMed PMID: 16109406.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model. AU - Danias,John, AU - Shen,Fran, AU - Kavalarakis,Manolis, AU - Chen,Bin, AU - Goldblum,David, AU - Lee,Kevin, AU - Zamora,Maria-Florencia, AU - Su,YanLing, AU - Brodie,Scott E, AU - Podos,Steven M, AU - Mittag,Thom, Y1 - 2005/08/16/ PY - 2004/12/14/received PY - 2005/05/25/revised PY - 2005/06/10/accepted PY - 2005/8/20/pubmed PY - 2006/4/1/medline PY - 2005/8/20/entrez SP - 219 EP - 28 JF - Experimental eye research JO - Exp Eye Res VL - 82 IS - 2 N2 - Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains. IOP was raised in one eye of Wistar (N = 5) and Brown-Norway(B-N)(N = 7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N = 7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined. Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones. The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP-stressed RGCs. Identification and enhancement of such factors could prove useful for glaucoma therapy. SN - 0014-4835 UR - https://www.unboundmedicine.com/medline/citation/16109406/Characterization_of_retinal_damage_in_the_episcleral_vein_cauterization_rat_glaucoma_model_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-4835(05)00187-9 DB - PRIME DP - Unbound Medicine ER -