Purpose
To evaluate the local and systemic toxicity of bismuth weight implantation in the upper eyelid of rabbits as an alternative to paralytic lagophthalmos treatment comparing to the gold weight implant.
Methods
Fifteen male albino rabbits 4 months old were randomly divided into 3 groups. All animals of group 1 underwent bismuth weight surgical implantation into the right upper eyelid (fig 1A); group 2 were submitted to the same procedures with gold weight implant instead of bismuth (fig 1B); and in the group 3 only anesthetic intervention was performed (control). All animals were examined before and 15, 30, 60 and 90 days after the surgery (fig 2). In each visit it were performed slit lamp examination, weight body measurement and blood samples were collected to serum analysis of AST and ALT enzymes, bilirubin, urea, creatinine and complete blood count. Samples of the eyelid, lung, liver, spleen, kidney, heart and brain were sent for histological analysis.The one-way analysis of variance was used to determine statistical differences.
Results
There was no significant difference in weight gain among the groups (p-value=0.068) and no changes were found on slit lamp eye examination. Two rabbits in the bismuth group had eyelid implant extrusion at the eighth week. No significant changes were observed in laboratory findings (p-value>0.05). There was no evidence of tissue toxicity in the histological analysis. Discrete inflammatory findings in the liver (p=0.59), kidney (p=0.67) and lung (p=0.32) were more frequent in bismuth groups, but no statistical significance was observed.
Conclusions
The bismuth weight implantation had no toxic effects compared with the gold weight and control group. Despite the extrusion cases, the bismuth weight seems to be an alternative to the gold weight for the treatment of lagophthalmos.