Please select the eligibility criteria that correspond to the clinical trial below.
Title: Cross-linking for Corneal Ulcers Treatment Trial
Brief Summary: The primary purpose of this study is to determine if patients randomized to corneal collagen cross-linking plus medical therapy will have a lower prevalence of positive bacterial or fungal cultures immediately after the procedure than patients who received medical therapy alone.

The secondary purpose of this study is to determine if patients randomized to corneal collagen cross-linking will have a better visual acuity at 3 and 12 months than patients who receive medical therapy alone.


Options:
A: Inclusion Criteria:

* diagnosis of infectious keratitis

Exclusion Criteria:

* corneal ulcer that has perforated
* corneal ulcer that has produced a descemetocele
* women who are pregnant or breastfeeding
* patients who are immunocompromised or unwilling or unable to comply with a medication regimen
B: Inclusion criteria:

* Corneal ulcer that is smear positive for either bacteria or filamentous fungus
* Pinhole visual acuity worse than 20/70 in the affected eye
* Not treated already with antimicrobial medications at presentation
* Age over 18 years
* Basic understanding of the study as determined by the physician
* Commitment to return for follow up visits

Exclusion criteria:

* Evidence of concomitant infection on exam or gram stain (i.e. herpes, both bacteria and acanthamoeba on gram stain)
* Impending or frank perforation at recruitment
* Involvement of sclera at presentation
* Non-infectious or autoimmune keratitis
* History of corneal transplantation or recent intraocular surgery
* No light perception in the affected eye
* Pinhole visual acuity worse than 20/200 in the unaffected eye
* Participants who are decisionally and/or cognitively impaired
C: Inclusion Criteria:

* Patient exhibit clinical signs of corneal infiltrate or beginning corneal ulcer on at least one eye, of suspected bacterial, fungal or mixed (bacterial and fungal) origin.
* Infiltrates and early ulcers up to a maximum 2mm in diameter; may lie close to the corneal limbus, but at a minimal distance of 2mm from central cornea.
* Infiltrates and early ulcer depth of a maximum of 300 μm, assessed by either OCT or Scheimpflug imaging
* All lesions must show an open epithelium with fluorescein positive staining
* No previous antibiotic/antifungal treatment OR at least no antibiotic/antifungal treatment for a minimum of 48 hours from last treatment
* Provide signed and dated patient consent form
* Patient willing to comply with all study procedures and be available for the duration of the study
* Male or female, \>18 years of age. No children or adolescents of 18 years and less of age will be included in this study.

Exclusion Criteria:

* Lesion/infiltrate involving the central 2mm diameter of the cornea
* Suspicion of non-infectious keratitis, viral or acanthamoeba keratitis or sterile infiltrate.
* Closed epithelium over the lesion
* Pachymetry of less than 400 microns at the thinnest point.
* Patients who cannot participate in the treatment or be monitored with frequent clinician controls as required in the study protocol.
* Corneal perforation
* Descemetocele
* Pregnancy or breastfeeding
* Active corneal herpetic disease
* Systemic treatment involving steroids
* Immunosuppressed/immune-compromised patients
* Patients with diagnosed eczema (or atopic dermatitis)
* Previous keratoplasty
* Patients with monocular vision
D: 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

Answer: B