To explore the clinical significance of ocular surface bacteria inhibition by cleaning eyelid margins before surgery in cataract patients.

Case-control study. Thirty-five patients (45 eyes) with age-related cataracts who were proposed to receive treatment of Phacoemulsification combined with cataract extraction and intraocular lens implantation at Peking University 3^rd hospital were included. The experimental group consisted of 9 males and 15 females with the average age of (69.8±11.5). The control group consisted of 6 males and 15 females with the average age of (61.8±16.2). In the experimental group, bacteria samples from the conjunctival sac and eyelid margins were collected at three times separately and were cultured for identification: first sampling was taken prior to application of any type of antimicrobial measures; second sampling was taken after application of lid scrub twice daily for 7 days to cleanse their eyelid margins by the patients;the last sampling was taken after patients' application of Levofloxacin antibiotic eye drops 3 times per day continuously for 3 days prior to surgery. In the control group, bacteria samples from the conjunctival sac and eyelid margins were collected at two times separately and were cultured for identification: first sampling was taken before application of any antimicrobial measures;second sampling was taken after patients' application of only Levofloxacin antibiotic eye drops successively for 3 days before surgery. Then the results of bacteria culture of the two groups above were compared.

In the experimental group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 83.3% (20/24), 70.8% (17/24), 45.8% (11/24), respectively; according to the bacteria cultures results of the second sampling (tanken after application of lid scrub for cleaning the eyelid margins for 7 days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 58.3% (14/24), 45.8% (11/24), 25% (6/24), respectively;According to the bacteria cultures results of the third sampling (taken after application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 20.8% (5/24), 20.8% (5/24), 4.2% (1/24), respectively. In the experimental group, we compared the bacterial positive rate of the samples taken after patients' application of antibiotics for 3 days to the bacterial positive rate of the samples taken prior to application of any antibacterial measures to have found that the total positive rate, the positive rates of common bacteria and rare bacteria decreased significantly (P<0.05) and the difference in between are of statistical significance. In the control group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures, the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 81% (17/21), 66.7% (14/21), 19% (4/21), respectively;According to the bacteria cultures results of the second sampling (taken after the application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 38.1% (8/21), 14.3% (3/21), 33.3% (7/21) respectively. When comparing the experimental group to the control group, the experimental group yielded significantly better results than the control group for the rate of reduction of rare bacteria in the eyelid margin after using antibiotics for 3 days. This is due to the lid scrub being used with the antibiotics. The difference are of statistical significance (χ²=6.518, P=0.017). There was no statistically significant difference between the experimental and control group in terms of the total positive rate as well as the positive rate of common bacteria and rare bacteria in the conjunctival sac.

The cleaning of the eyelid and eyelid margin with lid scrub prior to cataract surgery combined with antibiotics eye drops will achieve excellent antibacterial effects for common and rare bacteria in the eyelid and conjunctival sac. The antibacterial effect of using lid scrub with antibiotic eye drops is more favorable than that of using antibiotic eye drops only. However, the lid scrub eyelid hygiene products cannot replace preoperative antibiotics independently. (Chin J Ophthalmology, 2018, 54: 445-451)

Cataract extraction; Premedication; Antibiotic prophylaxis; Eyelids; Microbiota