Experimental study on the treatment of rabbit corneal melting after alkali burn with Collagen cross-linking

AIM: To evaluate the effect of Collagen cross-linking on the prevention of melting in rabbit corneas after alkali burn. METHODS: Twenty New Zealand white rabbits were randomly divided into model control group and collagen cross-linking treatment group. The second group of rabbits received collagen cross linked treatment. Both groups were applied with antibiotic eye drops to prevent infection. The corneas were evaluated for melting, opacity, pathological and immunohistochemistry, record the changes when 28 days after the animals were killed. RESULTS: In the control group, 6 out of 8 rabbits showed corneal melting after injury (14 +/- 4) days, while two corneal perforated. In collagen cross-linking treatment group, one rabbit showed corneal melting after injury 23 days, without corneal perforation; corneal dissolution rate between the two groups was significantly different (P <0.05). Pathological examination suggested that in the treatment group, mild corneal edema, mild damage to collagen fibers, inflammatory cell infiltration was significantly less than the control group. Immunohistochemistry showed that corneal collagen fibers arranged in neat rows in the control group. CONCLUSION: Collagen cross-linking treatment not only can prevent and delay the corneal melting after alkali burn, but also can reduce the destruction of corneal collagen fibers and infiltration of inflammatory cells in the corneal tissue.

PACK-CXL vs.antimicrobial therapy for bacterial,fungal,and mixed infectious keratitis:a prospective randomized phase 3 trial

Background:Infectious keratitis is a major cause of global blindness.We tested whether standalone photoactivated chromophore corneal cross-linking(PACK-CXL)may be an efective frst-line treatment in early to moderate infectious keratitis,compared with standard antimicrobial treatment.Methods:This is a randomized,controlled,multinational phase 3 clinical trial.Participants in fve centers in Egypt,India,Iran,Israel,and China,aged≥18 years,with infectious keratitis of presumed bacterial,fungal,or mixed origin,were randomly assigned(1:1)to PACK-CXL,or antimicrobial therapy.Outcomes measures included healing,defned as time to re-epithelialization of the corneal epithelial defect in the absence of infammatory activity in the anterior chamber and clearance of stromal infltrates.Treatment success was defned as the complete resolution of signs of infection.Results:Between July 21,2016,and March 4,2020,participants were randomly assigned to receive PACK-CXL(n=18)or antimicrobial therapy per American Academy of Ophthalmology(AAO)guidelines(n=21).No participants were lost to follow-up.Four eyes were excluded from the epithelialization time analysis due to treatment failure:two in the antimicrobial therapy group,and two in the PACK-CXL group.Success rates were 88.9%(16/18 patients)in the PACK-CXL group and 90.5%(19/21 patients)in the medication group.There was no signifcant diference in time to complete corneal re-epithelialization(P=0.828)between both treatment groups.Conclusions:PACK-CXL may be an alternative to antimicrobial drugs for frst-line and standalone treatment of early to moderate infectious keratitis of bacterial or fungal origin.