IMMEDIATE PARS-PLANA VITRECTOMY IN THE MANAGEMENT OF INADVERTENT INTRACAMERAL INJECTION OF GENTAMICIN - A RABBIT EXPERIMENTAL-MODEL

Purpose: Acute retinal toxicity secondary to inadvertent intracameral injection of massive doses of gentamicin is a devastating complication of cataract surgery, for which no treatment, to date, either surgical or medical, has been shown to be effective. A rabbit experimental mod el was used to examine the effect of immediate pars plana vitrectomy i n the management of inadvertent intracameral injection of gentamicin. Methods: Twenty-seven rabbit eyes were subjected to lensectomy with or without preservation of the lens capsule. Aphakic rabbit eyes and rab bit eyes with an intact lens capsule were then subjected to injections of massive doses (4 mg and 20 mg) of gentamicin into the anterior cha mber. Experimental eyes underwent an immediate pars plana vitrectomy a nd posterior segment lavage. The rabbits were killed after 7 days. Lig ht microscopic examination was then performed to ascertain the degree of retinal damage caused by the injection. Results: Rabbit eyes receiv ing immediate pars plana vitrectomy exhibited far less structural dama ge to the retina, as seen by light microscopy, than did corresponding control eyes. Furthermore, there appeared to be a protective effect of an intact lens capsule with regard to retinal damage. Conclusions: Im mediate pars plana vitrectomy and posterior segment lavage may allevia te the effects of intracameral injection of gentamicin. This prelimina ry study demonstrates the need to perform further studies with a vascu larized primate retina to evaluate immediate pars plana vitrectomy in the management of inadvertent intracameral injection of gentamicin.