Pathologic Analysis of Deep Lamellar Endothelial Keratoplasty and Descemet's Stripping With Endothelial Keratoplasty Specimens

Abstract

Purpose:: To compare the histopathologic features of specimens from corneal lamellar surgical procedures: deep lamellar endothelial keratoplasty (DLEK) and Descemet’s stripping with endothelial keratoplasty (DSEK).

Methods:: We retrospectively reviewed a consecutive series of 25 corneal specimens of 24 patients who underwent DLEK (11) or DSEK (14) by a single surgeon (JCS) at the Doheny Eye Institute from February 2006 to August 2006. Fifteen cases had a diagnosis of pseudophakic bullous keratopathy (PBK) and 10 cases had a diagnosis of Fuchs’s endothelial dystrophy (FED). Immediately following removal, tissue was placed in formalin prior to histologic analysis. Corneal specimens were stained with hematoxylin and eosin and PAS. Electron microscopical evaluation of tisse was also performed. For each specimen, the following parameters were calculated: thickness of stroma and Descemet’s membrane, and endothelial cell count per millimeter. To calculate the thickness of the stroma and Descemet’s membrane, five separate points were measured and then averaged. A student’s t-test was used to calculate statistical significance.

Results:: In the DLEK group, the average stromal thickness is 273 µm while in the DSEK group, the average stromal thickness is 0 µm (p<0.0001). In the DLEK group, stromal thickness is 344 µm in the FED subgroup and 225 µm in the PBK subgroup (p=0.26). For both groups (DLEK and DSEK) Descemet’s thickness is 13.7 µm in the FED subgroup and 14.1 µm in the PBK subgroup (p=0.78). Endothelial cell count is 4.9 cells/mm in the FED subgroup and 1.3 cells/mm in the PBK subgroup (p=0.01). Endothelial cell count is 2.1 cells/mm in the DLEK subgroup and 2.8 cells/mm in the DSEK subgroup (p=0.63).

Conclusions:: As expected through histopathological analysis, DLEK specimens involve the stroma while DSEK specimens do not. This further supports the principle behind each surgical technique. In addition, patients with FED have a greater density of endothelial cells than those with PBK at the time of surgery.

Keywords: cornea: clinical science • pathology: human