Effectiveness of Corneal Accelerated Crosslinking for Infectious Keratitis

Effectiveness of Corneal Accelerated Crosslinking Versus Conventional Treatment for Infectious Keratitis

The objective of this study is to evaluate the efficacy and safety of accelerated cross-linking (Avedro Inc., Waltham, USA) in the management of microbial keratitis as adjunctive therapy.

Investigators perform a comprehensive ophthalmological examination, including evaluation of risk factors (immunosuppressive status, ocular trauma, previous ocular surgery, contact lens wear, topical corticosteroids use), best-corrected visual acuity (Snellen chart), slit-lamp biomicroscopy, tonometry and fundoscopy. In addition, anterior segment optical coherence tomography imaging (Visante, Carl Zeiss Meditec, Dublin, California, USA), corneal scrapes, culture and clinical photographs at day 1, day 7, month 1 and 3 will be analyzed. Each participant will be assigned to one of four groups after randomization. Group 1: Initial ulcer on treatment with antibiotic plus sham (n = 66), these partcipants will receive only topical moxifloxacin 0,5% (Vigamoxi, Alcon, Texas, USA) and sham CXL; Group 2: Initial ulcer on treatment with antibiotic plus cross-linking (CXL) (n = 66) receive moxifloxacin plus CXL (riboflavin 0.1% during 10 minutes and irradiation 30 mW/cm2 during 3 minutes using accelerated CXL); Group 3: Refractory corneal ulcer on treatment with antibiotic plus sham (n=66), receive only topical antibiotic plus sham CXL; Group 4: Refractory corneal ulcer on treatment with antibiotic plus CXL will receive their standard medications plus CXL. Statistical analysis will be divided into four phases: 1) Analysis of compliance, 2) Intention to treat, 3) Losses to follow-up and 4) Variable-response (healing) using Stata/MP 12.0 (Stata Corp., College Station, TX).

Cross-linking in the management of microbial keratitis is an adjunctive therapy.This procedure is conducted under sterile conditions in the operating room. Tetracaine hydrochloride 0.5% (Ponti Ofteno, Sophia, Mexico) eye drops is apply for topical anesthesia. The corneal epithelium on the edge of the ulcer is cautiously removed using a microsponge. As photosensitizer, riboflavin 0.1% (Vibex, Avedro Inc, Waltham, USA) is used for 10 minutes. After impregnation, the participant´s cornea is irradiaded with UVA-light (370 nm) using 30 mW/cm2 for 3 minutes (which corresponds to a total dose of 5.4J/cm2) with accelerated cross-linking (Avedro Inc., Waltham, USA). After procedure, conventional treatment for keratitis remains unchanged.

Placebo surgery. This procedure is conducted under sterile conditions in the operating room. Tetracaine hydrochloride 0.5% (Ponti Ofteno, Sophia, Mexico) eye drops is apply for topical anesthesia. Investigators do not perform removal of the corneal epithelium in edge of the ulcer. The researchers conducted "the impregnation phase" applying drops of saline solution for 10 minutes. After impregnation fase, a device is placed in Avedro equipment off (Avedro Inc, Waltham, USA) this device emits white light for 3 minutes. After procedure, conventional treatment for keratitis remains unchanged.

All participants in this group receiving conventional therapy (moxifloxacin 0,5% for bacterial keratitis or natamycin for mycotic keratitis) plus accelerated cross-linking (Avedro Inc., Waltham, USA) under topical anesthesia using 0.1% riboflavin (Vibex, Avedro Inc, Waltham, USA) for 10 minutes and irradiation 30 mW/cm2 during 3 minutes.

Complications associated with accelerated corneal cross-linking, such as corneal perforation or progression

Inclusion Criteria: Subjects with infectious keratitis (initial or refractory to treatment) including bacterial or mycotic keratitis with size larger than 3 mm Exclusion Criteria: herpetic keratitis Acanthamoeba keratitis pregnancy endophthalmitis systemic immunosuppression

Investigators describe demographic characteristics of the participants, such as age, gender, etiology, intervention group and the response variables, complications and corneal healing.

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