Purchase this article with an account.
Ji Yeon Lee, Young-Hwa Moon, Myung-Hoon Chun, Su-Ja Oh; Functional consideration on the retinal responses to hypertensive glaucoma injury combined to immunochemical analyses of calcium-sensing receptor and calcium-binding proteins expression. Invest. Ophthalmol. Vis. Sci. 2014;55(13):2413.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The present study is aimed to evaluate retinal responses to hypertensive glaucoma injury through functional and morphological analyses for a better understanding on the pathogenesis of glaucoma.
Hypertensive glaucoma model was made by electrical cauterization of three episcleral veins on the same side eyes of Sprague-Dawley rats aged of 8 weeks. Experimental periods were set at 1 week, 2, 4, and 8 weeks post-operation. Electroretinography was recorded using by a Ganzfeld integrating sphere. Expression pattern and its alteration of calcium sensing receptor (CaSR) and calcium binding proteins (CaBPs) were analyzed by double immunohistochemistry and confocal microscopy.
Mild hypertension was induced. Electrical responses to hypertensive injury appear to reduce in the amplitudes of the a- and b-waves under scotopic condition into approximately a half of the normal value. Remarkably the amplitude of the b-wave at 2 weeks post-operation was reduced to one third of the normal value. In photopic responses, the amplitude of the b-wave at 1 week shows no difference compared to the normal value, whereas that at 2 weeks glaucoma shows ~60% reduce. CaSR expression is in the ganglion cells and displaced amacrine cells in the ganglion cell layer. Surveyed CaBPs in this study were calbindin D28K, calretinin, parvalbumin, protein kinase C-α and recoverin. Co-expression of CaSR and any kind of CaBPs scarcely appeared throughout all the experimental periods. At 4 and 8 weeks glaucoma, CaSR expression reduced a little compared to those in the normal and control retinas. Calbindin and calretinin expression reduced expecially in cellular processes distributed in laminas 2, 3, 4 of the inner plexiform layer at 8 weeks glaucoma retina. Protein kinase C-α and recoverin immunoreactivity was no large change compared to those of the normal and control retinas.
These findings suggest that mild hypertensive glaucoma injury elicits reduced electrical responses from the earlier glaucoma time point, while on the other hand immunochemical changes of CaSR and CaBPs appear at later glaucoma time point. The photoreceptor cells and Mueller glial cells may be vulnerable to such a mild hypertensive glaucoma injury than the other neuronal types.
This PDF is available to Subscribers Only