Clinical efficacy of conjunctival sac irrigation with normal saline before intraocular surgery

Objective To compare the effects of different doses of normal saline, irrigation durations and intervals of conjunctival sac irrigation before intraocular surgery in order to provide evidence for preparation of emergency intraocular surgery. Methods A total of 126 patients admitted to our ophthalmology department from September 2016 to May 2017 were recruited in this study. The patients were randomly divided into 3 groups, with 42 cases in each group, and were given conjunctival sac irrigation once with 5, 15, and 30 mL normal saline before the operation. The positive rate of bacterial culture, conjunctival congestion, corneal damage, and incidence of infectious endophthalmitis in 2 weeks after the operation were observed. Then based on the above dose results, 126 volunteers were subjected as study groups for different intervals. These participants were randomly assigned into 3 groups (n=42) cases, and were given conjunctival sac irrigation with normal saline for 3 times at intervals of 0.5, 1.0 and 1.5 h, respectively. The positive rate of bacterial culture and tear film rupture time after irrigation were observed. Results In different dose groups, there were no significant differences in the positive rate of bacteria and conjunctival congestion rate (P < 0.05). The 30 mL group had obviously higher conjunctival congestion rate than the 5 mL group (30.95% vs 9.52%, P < 0.05). No infectious endophthalmitis occurred in the 3 groups. The positive rate of bacteria was significantly reduced in different irrigation times and intervals after 3 rinses (P < 0.05). After irrigation for the first time, the positive rate was remarkably lower in the 0.5 and 1.0 h interval groups than the 1.5 h group (P < 0.05). After 3 times of irrigation, the tear film rupture time was statistically shorter in the 0.5 h group than the other 2 groups (P < 0.05), and no difference was seen between the latter 2 groups. Conclusion Conjunctival sac irrigation with 5 to 30 mL normal saline reduces the bacterial positive rate, and potential infection. The conjunctival irritation can be significantly reduced by as low as 5 mL normal saline. Irrigation for over 3 times, with low dose (5 mL) in 1.0 h before operation can obviously reduce the bacteria of conjunctival sac and tear film injury, and provide a safe microenvironment of conjunctival sac for emergency intraocular surgery.