Abstract
Purpose :
Protecting the retina in situations of acute retinal ischemia such as Central Retinal Artery Occlusion is not usually considered in the therapeutic approach of this entity.
We developed an experimental model of ischemia – reperfusion to test drugs that could diminish tissue damage in those situations.
Methods :
The study was performed in singenic male rats WAG-RijHsd, 12 weeks old, 300 g weight.
6 different intraperitoneal treatments were tested: folic acid, pravastatin, calmidazolium, nitroindazole, trifluoperazine and allopurinol. The animals were divided in 7 different groups, 6 groups of 8 animals for each treatment, and a control group of 4 animals that were only injected saline.
In one of the eyes of the animal, intraocular pressure was raised above the arterial pressure so blood flow through the central retinal artery was blocked. Contralateral eye did not undergo any procedure so it was used as a paired control. Ischemic insult was maintained for one hour, then treatment was injected intraperitoneally and reperfusion let again for another hour.
At the end of the experiment, both retinas were extracted and histologically analyzed. Tissue damage quantification was measured by counting the number of edematous nuclei in the external plexiform layer per 40x field. Edema affecting this layer is the first histological sign that can be observed in acute retinal ischemia.
ANOVA test was performed to compare all groups, and a then a Newman - Keuls test for paired samples to compare each group with the rest.
Results :
In each group of treatment, ischemic retinas showed statistically more damage than non – ischemic retinas (ANOVA, p = 0.01), as shown in Table 1.
When comparing all groups of ischemic retinas, each one of the treatments showed a statistically significative difference compared to the control group (p < 0.05). Damage prevention was higher in folic acid and nitroindazole groups. In fact, nitroindazole group reached statistically significative differences compared to pravastatin and allopurinol groups. These data are represented in Graph 1.
Conclusions :
Some drugs like folic acid or nitroindazole could prevent tissue damage in retinal ischemia – reperfusion syndrome.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.