Deep Trephination Allows High Rates of Successful Pneumatic Dissection for DALK Independent of Surgical Experience

To evaluate the relationship between surgical experience and the success rate of pneumatic dissection for deep anterior lamellar keratoplasty (DALK) using deep trephination.

A noncomparative case series evaluating the first 10 consecutive keratoconic eyes without deep stromal scarring, operated by 8 surgeons of 3 different experience levels, was conducted; there were a total of 80 patients. Standardized DALK was performed, including deep trephination 450 to 550 μm in depth and 9 mm in diameter, pneumatic dissection, removal of the stroma, and transplantation of a 9-mm partial-thickness anterior lamellar graft. The success rate of pneumatic dissection correlated with surgical experience.

Pneumatic dissection succeeded in 7, 7, 8, and 9 cases of 10 cases in the first group of 4 inexperienced surgeons (under 10 previous keratoplasties of any kind); in 9 and 10 of 10 cases in the second group of 2 relatively experienced surgeons (under 100 keratoplasties); and in 10 and 8 of 10 cases in the third group of 2 very experienced surgeons (more than 1000 previous keratoplasties). No difference between the groups was found to be statistically significant with the χ test (P > 0.05).

The standardized DALK technique using a deep trephination allows high success rates of pneumatic dissection even for surgeons inexperienced in keratoplasty.