'Top hat' wound configuration may enhance stability for full-thickness PK, study suggests

Compared with traditional and other various wound configurations, the "top hat" wound configuration appears to provide the most mechanical stability for performing femtosecond laser-assisted full-thickness penetrating keratoplasty, a study by researchers in Canada suggests.

Irit Bahar, MD, and colleagues evaluated the stability of five wound configurations created using a femtosecond laser in a laboratory model of PK. The study included 22 human corneoscleral rims, each mounted on an artificial anterior chamber. Of these, investigators created traditional PK wounds on five samples, top hat wounds on five, "mushroom" wounds on four, "zig zag" wounds on four and "Christmas tree" wounds on four, according to the study.

The researchers measured the pressures required to cause the wounds to burst after placing four, eight and 16 interrupted sutures.

In the traditional PK group, wounds began leaking at a pressure of 0 mm Hg after placing four sutures, 21.6 mm Hg after placing eight sutures and at 49 mm Hg after placing 16 sutures, the authors reported.

"No statistically significant difference was noticed in burst pressure with the zig zag and Christmas tree wound configurations compared with the traditional PK group," the authors noted.

The top hat wound configuration provided the greatest stability, with leakage occurring at a pressure of 102 mm Hg after placing 16 sutures. The mushroom configuration yielded the next best wound stability, with a burst pressure of 65.8 mm Hg, also after placing 16 sutures, according to the study, published in the February issue of Cornea.