Abstract
Purpose: :
In vitreous surgery, gas cataract is one of the major complications of fluid-air exchange for phakic eye. But the mechanism of gas cataract is still unclear. In this study, an experimental gas cataract model using various kind of gas was produced and the microscopic analysis was performed.
Methods: :
Around 2 kg of albino rabbits were prepared. All rabbit experiments adhered to the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. After general anesthesia, 2 ports vitrectomy (PREMIERE, STOLZ), and fluid-gas exchange using different types of gas (room air, pure nitrogen and oxygen) was performed. Control group was performed only vitrectomy. The changes of the lens were observed with stereoscopic microscope (OMS.75 TOPCON) from 0 to 90 minutes. Each tissue was fixed with Carnoy's fluid and stained with hematoxylin-eosin solution and 4HNE(4-hydroxynon-2-enal: a marker for oxidation).
Results: :
In macroscopic findings, no significant changes were observed in control group. After 10 minutes, opacity along posterior Y suture and the posterior surface of lens were observed at room air and oxygen group. In Nitrogen group, any opacifications was not observed. In the opacified lens, small particles were detected at posterior pole of lens and 4HNE-positive stain was observed at this small particles. In nitrogen gas group, only few small particles were detected and 4HNE-positive stain does not observed.
Conclusions: :
The mechanism of gas cataract is mainly related with oxidation than mechanical stimulation. Small particles induced by oxidative stress were one of the important causes for gas induced cataract.
Keywords: cataract • oxygen • vitreoretinal surgery