Abstract
Purpose: :
To compare the effect of intracameral Gentamycin (GM) injection using by 29G needle or 33G nano-fil system TM (WPI, Sarasota, FL, U.S.A) on corneal endothelium of rabbits.
Methods: :
Twenty four Japanese albino rabbits were used. GM (40mg/ml) was diluted to two folds (20mg/ml), twenty folds (2mg/ml), two hundreds folds (200ug/ml) and two thousands folds (20ug/ml). Each diluted GM (four concentrations) was injected to the anterior chamber of rabbits using by 29G insulin injector needles, or by 33G nano-fil system, respectively. Injection volume to each eye was 0.1ml. Corneal central thickness of all rabbits was measured using by an ultrasonic pachymeter at three days post injection, and then those eyes were enucleated for observation of light microscopy (LM) with toluidine blue stain, of scanning electron microscopy (SEM), and of transmission electron microscopy (TEM).
Results: :
Central corneal thickness after GM injection were from 428um to 486um using by 29G needle group, were from 413um to 491um using by 33G nano-fil group. There were no differences for corneal thickness between 29G and 33G group. Central corneal thickness for GM 20mg/ml injection samples (two folds dilution) were thicker than those for control (saline injection) in both group (p<0.01). 2) On LM with toluidine blue stain, corneal endothelium for GM 20mg/ml injection and GM 2 mg/ml injection samples showed remarkable vacuole formation in 33G group. In contrast, each GM injection samples showed mild damage in 29G needle group. On SEM findings, some of the cell membrane detached in both group.
Conclusions: :
Corneal thickness for GM 20mg/ml injection samples increased significantly in 29G and 33G group. The morphological changes for corneal endothelium using by 33G nano-fil system were more severe damage than those by 29G needle.
Keywords: drug toxicity/drug effects • cornea: endothelium • injection