Records of 36,000 consecutive cataract operations in 21 years reveal 31 infections—an overall rate of 0.086%. The first 20,000 cases, reported in 1964, had an infection rate of 0.11%.
Analysis of the most recent 16,000 cases regarding preoperative prophylactic topical antibiotics reveals an apparently significant variable. When neomycin sulfate 0.5% was used with two other antibiotics, there were six infections in 1,000 cases (rate, 0.6%). When chloramphenicol 0.4% was substituted for neomycin, there were three infections in 15,000 operations (rate, one in 5,000 or 0.02%). In combination when chloramphenicol was used with other antibiotics, six infections occurred in 26,307 operations (rate, one in 4,384 or 0.022%.
When other factors presumptively related to certain infections are considered, adjustment of the rates with and without chloramphenicol reveals a factor of 13 times in favor of combinations including chloramphenicol.