Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty

Abstract

To investigate the characteristics of the corneal topography with three-dimensional (3-D) anterior segment optical coherence tomography (AS-OCT) following Descemet's stripping automated endothelial keratoplasty (DSAEK). Thirty-four eyes of 33 patients following DSAEK were studied. In addition to conventional topographic maps, the elevation map of the intrastromal interface and pachymetric maps of the host and graft were obtained by corneal topographic analysis using 3-D AS-OCT. The coefficient of variation of the corneal power (CV-Pa, CV-Pp) and root mean squares of the corneal elevation (RMS-Ea, RMS-Ep) of the anterior and posterior corneal surfaces were determined. Based on the combination of the regularity and irregularity of the anterior and posterior surfaces, subjects were classified into four types: type 1, regular/regular; type 2, irregular/regular; type 3, regular/irregular; and type 4, irregular/irregular. The average graft decentration was 0.59 ± 0.23 mm. The proportion of types 1, 2, 3, and 4 were 59%, 9%, 24%, and 9 %, respectively. The CV-Pa (25.8 ± 8.9) and CV-Pp (-73.9 ± 18.0) of the type 1 corneas were significantly better than that of type 2 and type 3 corneas, respectively. The RMS-Ea (5.1 ± 1.3) and RMS-Ep (26.0 ± 7.3) of the type 1 corneas were significantly better than that of type 2 and type 3 corneas. An OCT-based corneal topographer might be useful in determining the factors associated with optical quality of the cornea following DSAEK by analyzing the topographic characteristics of host and donor separately.