Study On The Effect Of Conjunctival Sac Irrigation To Prevent Eye Infection Before Inner Eye Operation

Background:Endophthalmitis refers to the vitreous or aqueous humor induced by bacterial or fungal infection,in a few hours or days after the onset of infectious eyes can lead to irreversible blindness,seriously harm the health of patients.Therefore,it is very important to prevent endophthalmitis after endophthalmic surgery.Contamination of the eyes by microorganisms comes from the eyelids,surrounding skin,and conjunctiva,but the conjunctiva is considered a major source of symbiotic bacteria that increase the risk of endophthalmitis.Therefore,the prevention of endophthalmitis by preoperative eyelid and conjunctival disinfection has become an important research field.Currently,povidone iodine(PI),gentamicin,normal saline and mercury-containing preparations are commonly used as disinfectants for conjunctival sac washing.There is no uniform conjunctival sac washing agent and dose-related standard at present.Therefore,screening of rapid,effective and safe preoperative conjunctival sac disinfectant is of great clinical value in reducing the incidence of endophthalmitis and alleviating the pain of patients.Object:To compare the effect of different doses of normal saline,times of irrigation and interval of conjunctival sac irrigation on preventing eye infection after internal eye surgery.Methods and Results:This study is divided into two parts.Part one:All the 318 patients admitted to the study group with different doses were included in the study group.The subjects were all patients who planned to undergo internal eye surgery and needed conjunctival sac irrigation before surgery,and they could cooperate actively.Patients with open eye trauma and infectious eye diseases were excluded.The patients were randomly divided into 3 groups,106 cases in each group,and were given 5,15 and 30 mL normal saline irrigation once before the operation.The positive rate of bacterial culture,conjunctival sac congestion,corneal damage and local stimulation after the conjunctival sac irrigation were observed.The patients were followed up for infectious endophthalmia 2 weeks after the operation.A total of 318 patients were included in different dose groups,and there was no statistical difference in age and gender.The positive rate of bacteria before and after washing was statistically significant(P < 0.05).There was no significant difference in bacterial positive rate between groups(P > 0.05).No moderate and severe conjunctival congestion occurred,and the difference was statistically significant(P < 0.05).Conjunctival congestion rate(39.25%)in 30 mL group was significantly higher than that in 5mL group(12.26%),with statistically significant difference(P<0.01).Infectious endophthalmitis did not occur in 3 groups.Part two:318 volunteers were recruited as study groups at different intervals.The subjects were over the age of 18 years old,who had not used any eye medicine or received eye contact examination or treatment in the past 1 month and had no injuries.Excluding contact lens wearers,open eye trauma and infectious eye diseases;Randomly divided into 3 groups,106 cases in each group were given 3 times of normal saline irrigation at intervals of 0.5,1 and 1.5h respectively,and the changes of bacterial culture positive rate and tear film rupture time after conjunctival sac irrigation were observed.After three washings at different intervals,the bacterial positive rate was significantly reduced,and the difference was statistically significant(P<0.05).After the first,second and third irrigation,the positive rate of bacterial culture among the three groups was statistically significant(P<0.05),among which the positive rate of the 0.5 and 1h groups was lower than 1.5h(P<0.05),and there was no significant difference between the 1h and 1.5h groups.However,after the first and second irrigation,there was no statistically significant difference in tear film rupture time between the three groups.After the third irrigation,the difference in tear film rupture time between the three groups was statistically significant(P<0.05).Conclusions:Before inner eye surgery,washing conjunctival sac with 5-30 ml normal saline can reduce the bacterial positive rate,and washing with 5mL low dose can significantly reduce conjunctival stimulation.Reirrigation 0.5h or 1h before surgery can minimize the damage of the conjunctival sac bacteria and tear film,providing a safe conjunctival sac microenvironment for emergency surgery.