Comparative study of bacterial status from conjunctival sac of the elder Qiang minority and Han people with dry eye in Sichuan,China

AIM: To compare the status of bacteria in the conjunctival sac from the elder Qiang minority and Han people with dry eyes in Sichuan, China. METHODS: Total of 54 elder Qiang people with dry eyes (108 eyes) were examined by cluster sampling. In the similar habitation region of Han people, 80 (160 dry eyes) Han people were analyzed as the control group. The bacteria was separated from the inferior palpebral conjunctiva, then inoculated on blood plate for 48 hours and identified. RESULTS: Totally 24 strains of bacteria were cultured in either Qiang minority or Han c populations with 3 strains of them existed in both ethnic groups. The commonest bacteria in conjunctival sac in two ethnic groups were non-pathogenic bacterium. The composition of Corynebacterium in Han people (54.1%) was significantly higher than that in Qiang minority (27.4%) (chi(2)=11.6721, P=0.0006). The percentage of Sphingomonas Paucimobilis in Qiang people was higher than that in Han people (chi(2)=18.6442, P=0.0000). However, there was no significant difference between Qiang minority and Han people either in bacterial positive rate in conjunctival sac, or the composition of bacteria species and strains, or the composition of staphylococcus epidemids between two ethnic populations. CONCLUSION:There was no significant difference of bacterial positive rate in conjunctival sac from the elder of Qiang minority and Han people with dry eye, but the species of bacteria were different.

Antibacterial effect of povidone iodine disinfectant and antibiotic eye drops before cataract surgery

Objective:Investigate the distribution of bacteria in the conjunctival sac of two groups of cataract patients with different preoperative aseptic treatments,and compare the clinical effects of 0.5%povidone-iodine(PI)and antibiotic eye drops on killing conjunctival sac bacteria.Methods:400 cases of patients(400 eyes)who underwent cataract surgery in the Department of Ophthalmology of Baogang Hospital in Inner Mongolia from October 2019 to October 2020 were selected in a randomized controlled study.They were randomly divided into the experimental group(group A)and the control group(group B),with 200 cases in each group.Group A:the patients were given Gatifloxacin Eye Gel(3 times/day,1 drop/time)combined with Diclofenac Sodium Eye Drops(4 times/day,1 drop/time)before the operation;0.5%PI was administered to irrigate the conjunctival sac,with 0.9%Sodium Chloride Injection washing after 3 min;0.5%PI was administered to irrigate the conjunctival sac after operation.The corneal epithelium was observed after each irrigation.Group B:the patients were given Gatifloxacin Eye Gel(3 times/day,1 drop/time)combined with Diclofenac Sodium Eye Drops(4 times/day,1 drop/time)2 days and 1 day before the operation;0.9%Sodium Chloride Injection was administered to irrigate the conjunctival sac before and after surgical disinfection.Conjunctival sac specimens were collected for bacterial culture 2 hours before the operation,after irrigation,and after the procedure.The positive rate and the distribution of bacteria were compared between the two groups.Results:The difference in the positive rate of bacteria in the conjunctival sac between the two groups at different time points had a statistical significance(χ^(2)=11.498,p<.022).Conjunctival sac specimens were collected on admission and 2 hours before the operation.There was no significant difference in the pathogens with positive results between the two groups(p=.955;p=.073);there was a substantial difference in the distribution of positive pathogens between the two groups before and after surgical disinfection(p<.001);there was a significant difference in the distribution of pathogens between the two groups after the operation(p=.005).For Staphylococcus epidermidis,Corynebacterium,Enterococcus faecalis,Streptococcus,and other Gram-positive bacteria,there was a significant difference in the disinfection methods between the two groups at different time points(p<.001);for Staphylococcus aureus,Gram-positive cocci,and Gram-negative bacteria,there was no significant difference in the disinfection methods between the two groups at different time points(p=.113;p=.224;p=.146).There was no significant difference between the two groups with 0-10 and 101-1000 bacterial colonies at different time points(p=.370 and.071,respectively).When there were 11-100 bacterial colonies,there was a significant difference between the two groups at different time points(p<.001).There was no significant difference in corneal epithelial injury between the two groups at other time points(χ^(2)=4.133,p=.127).Conclusions:The combination of 0.5%PI disinfectant and antibiotic eye drops can effectively reduce the bacterial load of the conjunctival sac before operation.At the same time,it is safe and effective to irrigate the conjunctival sac with 0.5%PI disinfectant before the procedure.

Sustained release of brimonidine from polydimethylsiloxane-coating silicone rubber implant to reduce intraocular pressure in glaucoma

Glaucoma is the leading cause of irreversible blindness,affecting 111 million people by 2040 worldwide.Intraocular pressure(IOP)is the only controllable risk factor for the disease and current treatment options seek to reduce IOP via daily taking eye drops.However,shortcomings of eye drops,such as poor bioavailability and unsatisfied therapeutic effects,may lead to inadequate patient compliance.In this study,an effective brimonidine(BRI)-loaded silicone rubber(SR)implant coated with polydimethylsiloxane(BRI@SR@PDMS)is designed and fully investigated for IOP reduction treatment.The in vitro BRI release from BRI@SR@PDMS implant reveals a more sustainable trend lasting over 1 month,with a gradually declined immediate drug concentration.The carrier materials show no cytotoxicity on human corneal epithelial cells and mice corneal epithelial cells in vitro.After administrated into rabbit’s conjunctival sac,the BRI@SR@PDMS implant releases BRI in a sustained fashion and effectively reduces IOP for 18 days with great biosafety.In contrast,BRI eye drops only maintain IOP-lowering effect for 6 h.Therefore,as a substitute of eye drops,the BRI@SR@PDMS implant can be applied as a promising non-invasive platform to achieve long-term IOP-lowering in patients suffering from ocular hypertension or glaucoma.