Femtosecond laser-assisted corneoscleral lamellar keratoplasty for peripheral corneal disease

Abstract

Objective: To evaluate the effect of femtosecond laser-assisted corneoscleral lamellar keratoplasty (FL-CSLK) on peripheral corneal disease (PCD). Methods: Retrospective cohort study. Six patients (6 eyes) with PCD who underwent FL-CSLK in Qingdao Eye Hospital from March 2014 to March 2017 were grouped as the FL-CSLK group, including 4 males and 2 females, aged (46.7±17.9) years. In addition, 8 patients (8 eyes) with PCD who underwent traditional corneoscleral lamellar keratoplasty in the same period were included in the control group. The items for analyses were as follows: visual function recovery, including visual acuity, equivalent spherical power, and astigmatism; the state of the cornea, including the healing time of the corneal epithelium, the transparency of the graft, the thickness of the corneal graft and implant bed, and the loss rate of corneal endothelial cells; intraoperative and postoperative complications, including high intraocular pressure, interlayer effusion, delayed corneal epithelial healing, immune rejection, and primary recurrence. Paired t-test was used to compare the best corrected visual acuity (BCVA), equivalent spherical power, and astigmatism before and after operation. The BCVA and corneal graft epithelial healing time between the two groups were compared by independent sample t-test. Results: The 6 patients in the FL-CSLK group included 2 cases of Mooren ulcer, 3 cases of Terrien marginal degeneration, and 1 case of pellucid marginal degeneration. The control group consisted of 4 eyes with Mooren ulcer and 4 eyes with Terrien marginal degeneration. The BCVA (logarithm of the minimum angle of resolution) in the FL-CSLK group was 0.35±0.09 at 6 months after operation, which was significantly higher than that before operation (1.17±0.15; t=9.01, P<0.001) and at 6 months after operation in the control group (0.78±0.29; t=-3.96, P=0.003). The equivalent spherical power was (4.8±2.7) D, lower than that before operation (t=-3.71, P=0.014), and the astigmatism power was (10.1±4.1) D, lower than that before operation (t=6.04, P=0.002) in the FL-CSLK group. The healing time of the graft epithelium in the FL-CSLK group and control group was (8.5±3.3) days and (12.8±6.1) days, respectively, with no significant difference (t=-1.54, P=0.149). The central thickness of the graft in the FL-CSLK group was (525±47) μm at 6 months after operation, the central thickness of the implant bed was (189±119) μm, and the loss rate of the corneal endothelium was 7.5%±2.1%. In the control group, 1 case had intraoperative perforation, 2 cases had intracorneal hemorrhage, and 1 case had intracorneal epithelial implantation cysts and graft ulcer. There were no intraoperative and postoperative complications in the FL-CSLK group. Conclusions: FL-CSLK can yield good clinical results in the treatment of PCD. The smooth optical interface made by femtosecond lasers can help the patient achieve a good visual prognosis. The procedure reduces the risk of corneal perforation and thus improves the surgery safety.