Tobramycin in external eye disease: a double-masked study vs. gentamicin

A double-masked randomized study was conducted at four centers to compare the efficacy and safety of tobramycin and gentamicin ophthalmic ointment in the treatment of superficial external eye disease. Seventy-seven patients with blepharitis and/or conjunctivitis were evaluated for safety, and 56 of the 77 individuals also qualified for evaluation of drug efficacy. After a 10 day treatment regimen, 97% of the tobramycin treated patients and 91.3% of the gentamicin treated patients were clinically cured or improved. Antibacterial effectiveness studies in the conjunctiva showed that tobramycin eradicated or controlled 87.8% of the bacterial infections vs. 77.4% for gentamicin. There was also a 9.3% adverse reaction rate with tobramycin vs. 17.6% with gentamicin. Primary symptoms consisted of erythema, injection, discomfort and itching. All adverse reactions were mild and cleared upon discontinuation of the study drug. While the trends seem to favor tobramycin, no difference was statistically significant at the p less than or equal to 0.05 level. These results indicate that tobramycin is a clinically effective and safe topical antibiotic and that it is comparable to gentamicin for topical treatment of bacterial external eye infections. It also may be better tolerated than gentamicin.