Effect Of Capsule Staining On The Rabbit's Corneal Endothelium Activity With Domestic ICG

Objective:To evaluate the effects of different concentrations and expo- sure times for the domestic indocyanine green on corneal endothelium in rabbits' eyes.Methods:Thirty-six rabbits, eyes were randomly divided into four groups,Group A,B and C are 2.5mg/mL,5mg/mL,7.5mg/mL domestic ICG solutions,Group D is balanced salt solution(as a control) .The preparation of these four solutions are: in order to obtain an ICG 2.5mg/mL,5mg/mL,7.5mg/mL solutions,12.5mg,25mg,37.5mg of domestic ICG powder were directly dissolved in 0.5mL of the sterile water. This solution was mixed directly with 4.5mL of balanced salt solution.The Group D was prepared by mixing 1mL of sterile water for intravenous use with 9mL of balanced salt solution to obtain an control solution .The osmolalities of the dye solutions and control solution were between 271 and 276mOsm/kg,close to the osm- olality of the aqueous humor (290 to295mOsm/kg).then each group was divided into three subgroups with four kinds of solution applied to rabbit eyes30s,60s,90s.Surgical Technique as follows :New Zealand white rabbits weighing 2.8 to 3.0kg each were anesthetized by intravenous injection of anesthetic.After a side-port incision was made,a superior 3.2mm clear corneal incision was created with a diamond knife.Anterior capsule staining with ICG2.5mg/mL,5mg/mL,7.5mg/mL and balanced salt solution was directly injected through the side port using a 27-gauge cannulafollowed by the demand of the group instruction.After30,60,90seconds, Sodium hya- luronate was injected into the anterior.The activities of corneal endothelium enzymes LDH and NADH were investigated respectively,and the corneal endothelium histological changes also were observed.Results:There were no statistical significance for the activities of LDH and NADH among Group A,Group B and Group D (P>0.05).The activites of LDH in Group C directly are186.12±12.12A,169.97±11.14A,161.82±17.91A in 30s,60s,90s,The activities of NADH in Group C directly are178.86±12.67A,165.39±18.79A,158.81±17.48A, The differences of the enzymes activities among the Group C and Group A,B,D were signifficant(P<0.05).The activities of LDH and NADH depend on the ICG exposure time in Group C, shown a negative correlation between enzymatic activity and exposure times.r=-0.45(P<0.05).The Group C shows some histological destruction.Consults : Nighty seconds exposure to domestic ICG2.5mg/mL,5mg/mL in BSS had no adverse effect on corneal endothelial function,or viability in rabbit corneas.While 7.5mg/mL ICG in three different times had statistical significance on the rabbit's corneal endothelium activity ,which shows negative correlation between enzymes activities and exposure time(P<0.05).This study provides a safety profile for the corneal endothelium when domestic ICG is used as an intraocular tissue stain in ophthalmic surgery.