Abstract
Purpose: :
To establish optimal graft oversize for a new corneal trephine system.
Methods: :
Retrospective review of eighty-five PK’s performed by two experienced corneal surgeons at Massachusetts Eye and Ear Infirmary (MEEI) between January 1, 2005 and February 1, 2007. Three different operative combinations were examined: Group A (28 eyes, old trephine, 0.25mm oversize), Group B (25 eyes, new trephine, 0.25mm oversize) and Group C (32 eye, new trephine, 0.5mm oversize). Post-operative refraction, topography and survival of grafts were compared.
Results: :
Demographics and indications were similar in all groups. Mean post-operative astigmatism was higher (5.5 vs. 4.2 diopters (D)) in Group B vs. Group A (p<0.04). Corneal power was flatter for Groups A (38.7 D) and B (37.9) vs. Group C (42.8 D) (p<0.02 and p<0.01). Survival rates were similar for all groups (85.71% Group A, 88.0% Group B, 80.6% Group C) (p>0.05 for all).
Conclusions: :
An increase in graft oversize hastened visual recovery following the use of a new trephine system. Surgeons may need to adjust graft parameters when new instrumentation is introduced.
Keywords: cornea: clinical science • transplantation