J Korean Ophthalmol Soc.  1988 Aug;29(4):591-601.

Experimental Study on the Effect of the Flow Rate and Blood Aqueous Barrier After Cyclocryotherapy in the Rabbits

• Kwak HW
• Baik WK
• Kim JM
• Kim SM

Abstract

The purpose of the study is to investigate the changes of the blood aqueous barrier, the flow rate and IOP after cyclocryotherapy in the white rabbits. After cyclocryotherapy we injected intravenously a dose of 25mg/kg of fluorescein sodium and sampled the aqueous humor at 1 and 2 hour and measured the concentration of flouorescein sodium by means of HPLC(High Performance Liquid Chromatography). By the comparision study among the control group, 4 times cyclocryotherapy application group and 8 times cyclocryotherapy applications group during experimental period, the results were summarized as follows. 1. In the control group, the mean aqueous amount was 0.297+0.020ml, the flow rate was 3.282+0.426 ul/min. 2. In the cyclocryotherapy group, IOP was significantly decreased during experimental period. It was found that the IOP in the 8 times cyclocryotherapy application group was more decreased than that in the times cyclocryotherapy application group after 2 weeks. 3. There was marked increase of the concentration of fluorescein sodium in aqueous humour after acute cyclocryotherapy, but it was decreased to normal level at 4 weeks. The difference between the two groups was not found. 4. The flow rate was markedly decreased after acute cycrocryotherapy and was almost back to normal 4 weeks in two groups. There was difference between the two groups. 5. In Electron microscopic study, many wide intercellular gaps between the nonpigmented and pigmented epithelium are observed but the nucleus of the nonpigmented and pigmented epithelium are well preserved on the day of experiment. From 7 days the nucleus, and both nonpigmented and pigmented epithelium are markedly decreased in number. By 28 days the cytoplasm is shrunken, nucleus has disappeared, and a capillary near pig-ment epithelium obstructed but the basement membrane of thest cells is well pres-erved. 6. After cyclocryotherapy, The IOP decreased progressively during experimental period, but the flow rate was almost back to normal at 4 weeks. From the result we can deduce the outflow facility was not influenced by cyclocryotherapy. And so it was suggested from electron microscopic study that IOP lowering effect of cyclocryotherapy was due to quantitiative destruction of aqueous production.

MeSH Terms

Aqueous Humor
Basement Membrane
Blood-Aqueous Barrier*
Capillaries
Cytoplasm
Epithelium
Fluorescein
Rabbits*
Sodium
Fluorescein
Sodium