PURPOSE: To describe a new surgical technique for Ferrara ring implantation and to evaluate its safety and efficacy in keratoconus patients. METHODS: A new technique was developed for implanting the Ferrara ring through a single corneal incision. A prospective study of twenty keratoconus patients operated on with this new technique was performed. The exclusion criteria included good contact lens tolerance, presence of significant corneal scar, presence of other ocular or systemic diseases, pachymetry lower than 400 micrometers and keratometry limits higher than 65D. LogMAR visual acuity and keratometry were analyzed both pre- and postoperatively. All complications and complaints during and after surgery were registered. The minimum follow-up period was twelve months. RESULTS: The mean uncorrected visual acuity improved from 1.045 ± 0.478 (preop) to 0.586 ± 0.373 LogMAR units after a twelve month follow-up. The mean corrected visual acuity improved from 0.714 ± 0.542 (preop) to 0.264 ± 0.162 LogMAR units (p=0.001) twelve months after surgery. The mean keratometric values varied from 55.9D ± 4.4D to 51.5D ± 4.8D in the follow-up period (p<0.0001). Three months after surgery, all patients had stable visual acuity. There were no per- or postoperative complications. CONCLUSIONS: This study showed that it is possible to implant the Ferrara ring through a single incision. This new surgical technique showed significant improvement in both corrected and uncorrected visual acuity and showed corneal flattening twelve months after surgery. No complications or complaints were observed.
Keratoconus; Ophthalmic surgical procedures; Prostheses and implants; Efficacy; Safety; Quality of control
