Impact of infection causes in DALK’s keratoplasty
First Author: C.Fernandez Alcalde SPAIN
Co Author(s): A. Boto de los Bueis M. del Piñal Álvarez de Buergo B. González Ferrer P. Fernández Pérez A. Del Hierro Zarzuelo P. Vázquez Colomo
The main purpose of this study is to examine the impact of DALK’s indication cause on the remaining stroma on the receptor’s cornea and the postsurgical endothelial cell count (ECC).
Ophthalmology Department of University Hospital La Paz, Madrid, Spain.
Single-centre retrospective observational cross-sectional study, reviewing medical records, corneal topography and densitometry (Pentacam, Oculus), and specular microscopy of 33 eyes that underwent a DALK procedure by the same surgeon, between January 2006 and January 2020 at 12 and 24 months after keratoplasty. The biostatistical analysis of all data was performed using the non-parametric test Kruskal-Wallis and Mann-Whitney, taking as significative p values inferior than 0.05.
Cohort division based on indication: 18.2% bacterial infection (mainly Pseudomonas), 18.2% Herpes, 24.2% dystrophies, 30.3% ectasias and 9.1% burnt injuries. Mean VA preDALK was 0.125/1 and postDALK 0.532/1 at 24 months (0.472 in infection, 0.75 in dystrophies and ectasias). Four eyes had ECC preDALK, mean 2531 cells. Topography mean K1 41.4 and K2 45.9 at 12 months and 42.4 and 47.4 at 24; k2 was higher in ectasias (Kruskal-Wallis p=0.026). ECC mean at 24 months 1572 cells; lower on Pseudomonas (1275). Mean posterior stroma densitometry was 13.8um, higher in Pseudomonas and Herpes (Kruskal-Wallis p=0.04)(manual DALK 15.86um vs BB DALK 15.14um).
ECC preDALK is usually impossible to perform, assuming a functioning endothelium in absence of corneal edema. On our case series, most common DALK’s indication is corneal ectasia. VA postDALK at 24 months was higher on ectasias and dystrophies. Statistics suggest that ECC postDALK might be lower on Pseudomonas and higher on ectasias, that could be explained due to deep corneal or anterior chamber inflammation related to infection. Statistically significant differences were found on posterior stroma density in the manual technique, being higher on Pseudomonas and herpes; what could be related to lower posterior visual acuity.