Deep suturing technique for penetrating keratoplasty

Purpose. To evaluate the effect of a new suturing technique on postkeratoplasty visual rehabilitation time and refractive error. Methods. Penetrating keratoplasty was performed on 17 eyes with keratoconus using a modified suturing technique. A donor button 8.0 mm in diameter was sutured into a 7.75-mm recipient bed with both deep and superficial sutures. The deep sutures consisted of either a single 16-bite 10-0 nylon running suture (n = 7) or eight interrupted 10-0 nylon cross-stitches (n = 10). These sutures were passed into the mid-stroma of the donor cornea and exited through the donor endothelium, then passed through the endothelium of the recipient cornea and exited from its mid-stroma. Thereby all parts of the deep sutures remained below the corneal surface. To further secure the surgical wound, in each case a running 16-bite 10-0 nylon superficial suture was also placed. Care was taken to maintain the bites of the superficial suture above the level of the deep sutures. The superficial suture was removed 3 months after surgery. Vision and refraction were recorded 1 day and 1 month postoperatively and 1 and 3 months after suture removal. A paired Student t test was used to verify the significance of changes in visual acuity and refraction recorded at different examination times. Results. As early as 1 month after surgery, spectacle best-corrected visual acuity 20/40 or more and refractive astigmatism less than 4 diopters (D) were recorded in each eye and maintained with two exceptions at the later examination times. In two patients, postoperative astigmatism increased from 4.5 to 5 D after suture removal. Conclusions. Deep suturing allowed quick visual rehabilitation while minimizing postkeratoplasty astigmatism in the patients with keratoconus operated on in this series.