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.
Allen HF, Mangiaracine AB. Bacterial Endophthalmitis After Cataract ExtractionII. Incidence in 36,000 Consecutive Operations With Special Reference to Preoperative Topical Antibiotics. Arch Ophthalmol. 1974;91(1):3-7. doi:10.1001/archopht.1974.03900060007002