8.5/8.6-mm Excimer Laser–Assisted Penetrating Keratoplasties in a Tertiary Corneal Subspecialty Referral Center: Indications and Outcomes in 107 Eyes

Abstract

Purpose: To report the indications and outcomes of 8.5/8.6-mm excimer laser–assisted penetrating keratoplasties (PKPs) at a tertiary corneal subspecialty referral center. Methods: This retrospective, descriptive, observational study included 107 PKPs performed in 96 patients (mean age, 53 ± 12 years). The patients' indications for surgery, best-corrected visual acuity, surface regularity index, surface asymmetry index, topographic astigmatism, central endothelial cell density, central corneal thickness, and graft status were recorded preoperatively, 6 weeks postoperatively, and before (12 ± 2 months) and after (19 ± 4 months) the suture removal. Results: The surgeries included 48 primary PKPs and 59 repeat PKPs. The main indications were corneal ectatic disorders (50%), severe corneal keratitis (21%), and corneal scars (16%) in the primary PKP group and highly irregular astigmatism after PKP (51%) and previous graft decompensation (37%) in the repeat PKP group. From preoperative measurements to the last follow-up visit without sutures, we found significant improvements (P < 0.001 for all) in visual acuity (0.7 ± 0.3 LogMAR to 0.3 ± 0.2 LogMAR), surface regularity index (1.5–1.0), and surface asymmetry index (2.59–1.1). At the last follow-up, the mean outcome measurements did not significantly differ between the primary and repeat PKP groups. Overall, 89 grafts (83%) remained clear at the last follow-up. Conclusions: In cases of ectatic disorders and highly irregular astigmatism after keratoplasty, 8.5/8.6-mm excimer laser–assisted PKP seems to be an excellent treatment option, achieving a significant improvement in visual acuity.

Stadiengerechte Therapie des Keratokonus

“…Besonders bei notwendiger Rekeratoplastik wegen kleinen (dezentrierten) primären Transplantats mit hohem irregulärem Astigmatismus (sog. "Keratokonusrezidiv") erlaubt die zentrierte 8,5/8,6-mm-Excimerlaserassistierte Retrepanation oft, das gesamte alte Transplantat inklusive der Spender-Empfänger-Appositionsnarbe kontaktfrei zu exzidieren [74]. Diese Variante lässt in Kombination mit Einzelknüpfnähten bei geringer Dezentrierung nach unten auch die PKP bei fortgeschrittener PMD (= Keratotorus) mit kaudal sehr dünner (mittel)peripherer Hornhaut zu (Abb.…”

Need for explantation of an intrastromal titan ring after penetrating keratoplasty in two patients

“…In conclusion, due to the uncertainty of the results of the implantation of the Krumeich ring and the complications described in this paper, we recommend not to use this titan ring any further. The gold standard method, which is supported in our department, in cases of extremely progressed keratoconus remains excimer laser assisted penetrating keratoplasty 17 or deep anterior lamellar keratoplasty (DALK) if there is no stromal scarring.…”

“…The examination showed a major steepening of the cornea from 12 to 4 o’clock without any signs of graft rejection, however with a persistent high myopia and irregular astigmatism (Figure 2(d) and (e)). Due to contact lens intolerance we performed an excimer laser repeat-PKP 8.5/8.6 mm with two continuous double running cross-stitch sutures according to Hoffmann (in Alfaro Rangel et al) 17 in our department 2 years later. The preoperative BCVA was 20/40 OD (−10.75 sph, −3.00 cyl × 90°).…”

Transplantatversagen nach PKP und DMEK: Was ist die beste Option?

“…The basic rule for graft size in PKP is: To make it as large as possible for optical reasons and transplant as many endothelial cells as possible, and to make it as small as necessary due to immunological implications, while maintaining a sufficiently large distance of the suture from the trabecular meshwork to avoid postoperative increase in pressure – here “one size fits all” does not apply. Typically, a re-PKP 8.5/8.6 mm excimer laser is recommended in order to treat any concomitant edema, scarring, and curvature at the same time 38 . However, this assumes that the cornea is large enough and that the previous PKP is not too off-centered.…”