Long-term refractive and visual outcome after penetrating keratoplasty only versus the triple procedure in Fuchs' dystrophy

Abstract

Long-term refractive and visual outcome after penetrating keratoplasty (PK) only and the triple procedure in eyes with Fuchs' endothelial dystrophy were assessed and compared. Retrospective, non-randomized, cross-sectional, clinical, single-centre study. Ninety-two eyes of 87 patients were divided into two groups. Group 1 consisted of 28 eyes (mean age 62+/-13 years) that had undergone PK only and group 2 consisted of 64 eyes (mean age 69+/-10 years) that had undergone the triple procedure. Inclusion criteria were: (1) Fuchs' dystrophy, (2) central nonmechanical trephination, (3) double-running suturing technique and (4) availability of 'two-sutures-out' findings. In all eyes, a central trephination was performed (donor trephination from the epithelial side) using the 193-nm excimer laser along metal masks with eight 'orientation teeth/notches'. A double-running 10-0 nylon suture was applied in all eyes. Subjective refractometry (trial glasses), standard keratometry (Zeiss) and corneal topography analysis (TMS-1, Tomey) were performed in all eyes with 'two-sutures-in', 'one-suture-out', and 'two-sutures-out'. Main outcome measures included refractive cylinder, keratometric and topographic net astigmatism, keratometric and topographic central power, best-corrected visual acuity (BCVA), spherical equivalent (SE) of manifest refraction, surface regularity index (SRI), surface asymmetry index (SAI), and regularity of keratometry mires. The results were compared between the two groups (i.e. group 1 vs group 2) at various stages (i.e. 'two-sutures-in', 'one-suture-out', 'two-sutures-out'). Refractive cylinder in dioptres [D] was 2.5/2.0/2.5 vs 2.0/1.5/3.0, keratometric astigmatism [D] was 3.5/2.6/3.0 vs 3.5/3.1/3.5 and topographic astigmatism [D] was 3.9/4.1/4.9 vs 4.2/5.0/5.1. Keratometric central power [D] was 41.7/42.4/43.8 vs 41.5/41.9/43.3 and topographic central power [D] was 42.3/43.6/43.7 vs 42.6/41.8/44.3. BCVA was 0.5/0.6/0.6 vs 0.5/0.5/0.5. SE [D] was 0.0 /0.0/-0.5 vs -0.5/-0.5/-1.1. SRI was 1.5/1.1/1.0 vs 1.4/1.4/1.2 and SAI was 1.0/0.8/1.0 vs 1.3/1.2/1.0. The proportion of 'regular' and 'mildly irregular' keratometry mires was 44% / 69% / 68% vs 29% / 46% / 66%. The differences between the two groups did not reach statistical significance at any of the stages. Refractive and visual outcome after the triple procedure did not differ significantly from that after PK only. Therefore, we recommend the triple procedure in elderly patients with Fuchs' dystrophy and cataract to avoid delayed visual rehabilitation and a second surgical procedure.