Sequential in vivo confocal microscopy study of corneal wound healing after cross-linking in patients with keratoconus.

PURPOSE: To evaluate the short- and long-term sequential histological changes of the cornea in vivo after corneal collagen cross-linking (CXL) in patients with keratoconus. METHODS: Eighteen patients with keratoconus (Amsler-Krumeich classification: stages I, II, and III) underwent CXL with riboflavin/ultraviolet A (UVA) in one eye. The corneas were examined preoperatively and within 5 hours, 7 and 14 days, and 1, 3, 6, 9, 12, 18, 24, and 36 months after the procedure using in vivo confocal microscopy. RESULTS: Early changes included edema, superficial nerve loss, cellular modifications, and isolated endothelial damage. At intermediate time points, there was nerve fiber regeneration, increased reflectivity of the extracellular matrix, enlarged keratocytes and extracellular deposits, and remodeling of the endothelial layer (two eyes). At later time points, loss of keratocytes and remodeling of the extracellular deposits were noted. CONCLUSIONS: Although the cornea has no significant tissue modifications clinically after CXL, this study has shown that corneal wounding by riboflavin/UVA collagen CXL induces cellular wound-healing mechanisms and alters the normal structure and cellularity of the cornea for up to 36 months.

Treatment of advanced acanthamoeba keratitis with deep lamellar keratectomy and conjunctival flap.

PURPOSE: To describe whether deep lamellar keratectomy with a conjunctival flap is effective for the treatment of Acanthamoeba keratitis. METHODS: Two patients (three eyes) had at least a 4-week history of painful keratitis misdiagnosed as herpetic keratitis and bacterial keratitis. Both patients were started on multiple topical antiamoebic drugs after Acanthamoeba infection was confirmed. No improvement was observed after 3-4 weeks. Surgery was then performed. Peribulbar anesthesia was given, and the infected tissue was removed by deep lamellar keratectomy. A bipediculate conjunctival flap was put in place and secured with interrupted 10-0 nylon sutures. RESULTS: Both patients experienced immediate pain relief. The infection was controlled and all medications were tapered. There were neither necrosis nor retraction of the flap. Final examination revealed a Best-corrected visual acuity (BCVA) of 20/100 in each eye in the patient described in case number one at 30 months, and 20/100 in the patient described in case number two at 13 months. CONCLUSION: Deep lamellar keratectomy with a conjunctival flap is a suitable approach to help control the infection and to help relieve pain in patients with advanced Acanthamoeba keratitis.