Perforating keratoplasty with an intracorneal ring

We evaluated the clinical feasibility of an intracorneal ring for penetrating keratoplasty (PKP) designed to decrease postoperative corneal astigmatism.

A steel alloy ring was used for 8-mm PKP. The prospective study was comprised of 15 consecutive patients who underwent PKP for different corneal pathologies. The mean age was 52 years (range, 20-74 years). The Guided Trephine System was used in all cases for the preparation of the donor button and the recipient bed to ensure identical dimensions. The donor button with the surrounding ring in place was sutured in place with a 10-0 nylon double-running suture.

Except for one patient who had an allergic reaction to alloy components, no significant complications were observed. Mean reepithelialization occurred within an average of 4 days (range, 3-5 days). In 80% of the cases, stromal graft edema and Descemet's folds disappeared at 14 days after surgery. Average removal time of the intracorneal ring was 6 months (range, 3-9 months). Mean corneal astigmatism was 2.71 (standard deviation [SD], 1.37) diopters (D) before surgery compared to 2.10 (SD, 1.09) D at 1 month, 2.07 (SD, 1.26) D at 3 months, 2.29 (SD, 0.86) D at 6 months, and 2.94 (SD, 1.05) D at 12 months. In four eyes (27%), ruptures of one of the double-running antitorque sutures required resuturing.

The intracorneal ring prevented the donor button from distortions related to peripheral changes or suture traction. A sutured intracorneal ring appears to be a safe and effective aid in keratoplasties. Further evaluation in a multicenter study with larger patient numbers and indication-specific longer follow-ups is under way.