Influence of age on conjunctival bacteria of patients undergoing cataract surgery

Abstract

Aim To ascertain the effect of elderly in the conjunctival bacteria frequency of patients undergoing cataract extraction. Methods A retrospective case series study of 4432 consecutive patients who underwent cataract surgery, without excluding any of them for having pre-existing diseases. Their preoperative conjunctival culture were performed over a 3-year period (1994)(1995)(1996). Bacteria were grouped in nine categories and patients were divided into seven groups, according to age; comparisons between groups were made by means of the v 2 test, and the Mantel-Haenszel test to analyse age as a confounder, using SPSS program, version 12. Results Patients aged over 74 years accounted for 41.4%; women predominated among this group (61.4%), but not in the patients younger than 75 (47.7%); In the whole sample women accounted for 53.4%. Patients aged 75-96 years had a greater frequency of: Corynebacteria, Staphylococcus aureus, Streptococcus sp. (except Streptococcus pneumoniae), Gram-negative cocci and Gramnegative rods (except Haemophilus sp.) and 'other bacteria' categories than those aged 3-74 years. Different bacteria frequency in both sexes produced a confounding effect in the comparison between age-groups. Men had more Staphylococci coagulase (-), S. pneumoniae and Gram-negative rods than women. Conclusions Elderly patients awaiting cataract surgery had more conjunctival bacteria than those younger than 75 years, except Staphylococcus coagulase negative, S. pneumoniae and Haemophilus sp. At any age, men had more bacteria than women. These increments of frequencies could increase the risk of intraocular surgery contamination.

The conjunctival bacterial pattern of diabetics undergoing cataract surgery

“…In addition, their patients were younger (mean age 67 years) than ours (mean age 73 years), which could condition their flora prevalence. 9 Undoubtedly, the great number of patients contained in our sample allows us to identify this diabetic bacterial pattern, although the prevalence of the affected bacteria is not strikingly high. However, our big sample of patients also allows us to differentiate the influence of diabetes on the conjunctival bacterial flora from other factors affecting the prevalence of these flora.…”

“…7 This age range is also the lifetime period when most patients need to be operated on for cataracts. 2,8,9 This potential quantity of patients threatened with a poor visual acuity is a reason for preventing diabetics from PE. But, in addition, among the huge quantity of patients undergoing cataract operation, an increased PE incidence has often been associated with diabetes; [10][11][12][13][14] however, not many studies have been carried out to assess this fact and its causes.…”

The antibiotic resistance pattern of conjunctival bacteria: a key for designing a cataract surgery prophylaxis

“…The specimens collection and the culture technique were described elsewhere, 11,12 except for two modifications: first, we used smooth sterile plastic loops for taking the samples instead of a platinum loop (both microliter size loops); second, after the reading of the culture media, incubated 48 h, the chocolate-agar plates were incubated in microaerobiosis for 5 more days. The antibiotic susceptibility tests were carried out in accordance with the National Committee for Clinical Laboratory Standard (NCCLS), using three antibiotics profiles adapted to the current general bacteria resistance, as follows: for rapid growing and non-exigent bacteria, combined Dade-Behring panels were used, which included the identification tests, (for Staphylococci and Enterococci, panel PC23; for Gram-negative rods, panel PC38, substituted by PUC37 in July, for including the cefuroxime test).…”

“…Patients having combined surgical procedures of phacoemulsification and pars plana vitrectomy were excluded too, due to the difficulty of collecting these patients samples in the same conditions as in the planned surgeries. 11,12 In the Autoscan4 microbiologic system, the following were registered: the patients demographic data and their clinical record number; the identification, kind, origin, and collecting date of the samples. These samples were cultured and the isolated bacteria were identified.…”

“…These samples were cultured and the isolated bacteria were identified. Antibiotics sensitivity tests were performed on every bacteria considered pathogen, 11,12 but on the coagulase-negative Staphylococci (CNS) only when more than 5 colonies per microlitre were isolated (this is the inclusion criterion of our Ophthalmology Department assuming that a low density of nonpathogen bacteria implies a low risk of intraocular contamination). Incidence of PE per 10 000 cataract operations.…”