The Effect Intravitreal Dexamethasone and Antibiotic Therapy after Vitrectomy

ABSTRACT

Bacterial endophthalmitis is an ocular emergency that requires rapid diagnosis and therapeutic decision making. The introdection of intravitreal injection of antibiotics has been a major advancement because it has resulted in a marked improvement in visual outcome. The intravitreal injection of steroids may be potentially useful in the treatment of endophthalmitis and other ocular inflammatory diseases. Forty eyes of pigmented rabbits were used, and divided into two groups. Group I was eyes without vitrectomy. In the right eye, 100 microliter of 1mgvancomycin, 400 microliter amikacin and 400 microliter dexamethasone injected was done. Group II was eyes with vitrectomy and lensectomy. At 2 weeks after lens and vitreous removal, rabbit eyes received an injection of a combination of 1mg vancomycin, 400 microliter amikacin and 400 microliter dexamethasone in right eye and BSS in left eye. The effect of combination injection was examined by light and transmission, scanning electron microscope at 3 days, 1 week, 2 weeks and 6 weeks following injection. The injection of combination without vitrectomy produced no toxicity. After injections of either combination or BSS after vitrectomy, macrophages were observed on the surface of retinal pigment epithelium and disorganized outer segments. This finding seems to be produced by vitrectomy procedure rather than drug toxicity. These results supports the hypothesis that the injection of these combinations is not toxic to aphakic/vitrectomized eyes.