Endothelial cell density and corneal graft thickness following excimer laser vs. femtosecond laser-assisted penetrating keratoplasty—a prospective randomized study

Abstract

Purpose The study aims to compare the impact of non-mechanical excimer laser-assisted (EXCIMER) and femtosecond laserassisted (FEMTO) trephinations on graft endothelial cell density (ECD) and graft thickness before and after suture removal following penetrating keratoplasty (PK). Methods The inclusion criteria for this prospective, randomized, clinical study were as follows: (1) surgeries performed by one surgeon; (2) primary central PK; (3) keratoconus (KC) or Fuchs' dystrophy (FUCHS); (4) no previous intraocular surgery; (5) graft oversize, 0.1 mm; and (6) 16-bite double-running suture. In 68 eyes of 68 patients (mean age: 53.3 ± 19.8 years), PK was performed using either 193-nm MEL70 excimer laser (BEXCIMER^: 17 KC, 18 FUCHS) or 60-KHz femtosecond laser (BFEMTO^: 17 KC, 16 FUCHS) trephination. Specular microscopy (EM 3000) and pachymetry (EM 3000; Pentacam HR; Casia SS-1000) were performed before removing the first suture (11.4 ± 1.9 months) and after removing the second suture (22.6 ± 3.8 months), but before any additional ophthalmic surgery. Results ECD did not differ significantly (P ≥ 0.436) between EXCIMER and FEMTO either with Ball-sutures-in^(1887 ± 409 vs. 1886 ± 438) or with Ball-sutures-out^(1703 ± 379 vs. 1737 ± 362). Central corneal thickness and corneal thickness at the thinnest point of the cornea did not differ significantly between EXCIMER and FEMTO either with all-sutures-in (P ≥ 0.096 and P ≥ 0.653) or with all-sutures-out (P ≥ 0.636 and P ≥ 0.717). Conclusions EXCIMER and FEMTO trephinations from the epithelial side seem to have no disadvantages regarding endothelial cell loss after PK, and both surgical procedures are safe for the endothelium. A larger sample size and longer follow-up are needed to evaluate the long-term impact of EXCIMER and FEMTO trephinations on ECD.

Endothelial Cell Density and Central Corneal Thickness following Penetrating Keratoplasty of Acanthamoeba Keratitis Patients – A Retrospective Cross-Sectional Observational Study

“…The donor oversize was 0.1 mm in all cases using excimer laser trephination [18], 0.25 mm with the Hessburg-Barron vacuum, and 0.5 mm for handheld trephination. The trephination edge was marked with the respective metal mask or trephine, the size and shape of which was chosen according to the size and shape of the lesion.…”

Unterschiedlicher Verlauf von Immunreaktionen und Endothelzellverlust nach perforierender Low-Risk-Keratoplastik und Descemet Membrane Endothelial Keratoplasty bei Fuchs-Endotheldystrophie

“…CD decreased from 2779 ± 413 cells/mm 2 preoperatively to 1303 ± 454 cells/mm 2 after 1 year[23] Tóth et al (2019). showed endothelial cell loss from 1887 ± 409 cells/mm 2 before the second suture removal to 1703 ± 379 cells/mm 2 after the second suture removal after excimer laser PKP and from 1886 ± 438 cells/mm 2 before suture removal to 1737 ± 362 cells/mm 2 after suture removal after femtosecond laser PKP at FED[24].When assessing endothelial cell loss in the present study, the FED indication for surgery should not be ignored. For example, ▶ Fig.5Course of pleomorphism based on the mean 6A value (%) over the study period (U2 = 6 weeks postoperatively, U3 = 6 to 9 months postoperatively, U4 = 1 to 2 years postoperatively) in PKP (penetrating keratoplasty; as a dashed graph) and DMEK (Descemet membrane endothelial keratoplasty; as a solid graph).…”

“…Die Zelldichte sank von 2779 ± 413 Zellen/mm 2 präoperativ auf 1303 ± 454 Zellen/mm 2 nach 1 Jahr[23]. BeiTóth et al (2019) zeigte sich ein Endothelzellverlust von 1887 ± 409 Zellen/mm 2 vor der 2. Fadenentfernung auf 1703 ± 379 Zellen/mm 2 nach der 2.…”

“…Fadenentfernung auf 1703 ± 379 Zellen/mm 2 nach der 2. Fadenentfernung nach Excimer-Laser-PKP sowie von 1886 ± 438 Zellen/mm 2 vor Nahtentfernung auf 1737 ± 362 Zellen/mm 2 nach Nahtentfernung nach Femtosekunden-Laser-PKP bei FED[24].Bei der Bewertung des Endothelzellverlustes in der vorliegenden Studie sollte auch die OP-Indikation FED nicht außer Acht gelassen werden Langenbucher et al (2002). zeigten bspw., dass der Zellverlust nach PKP bei der FED signifikant höher war als bei Keratokonus und signifikant niedriger als bei bullöser Keratopathie (jeweils p < 0,0001).…”

Impact of Pre- and Intraoperative Factors on Endothelial Cell Density in the Early and Late Stage after Penetrating Keratoplasty

“…Several variables have been reviewed so far as impacting on postoperative ECD following PKP. Some trials studied donor age [8 -10], recipient age [11 -13], donor endothelial cell density [9,14,15], recipient baseline endothelial cell density [16], donor cause of death [17], the intraoperative approach of different surgeons [7], and the trephination procedure employed [18,19].…”