Assessment and Correlation of Corneal Endothelial Cell Changes in Different Stages of Keratoconus in Non–contact Lens Wearers

Supplemental digital content is available in the text. SIGNIFICANCE The endothelial changes in keratoconus are of interest because these can affect the surgical plan in management. Previously, many studies have evaluated the endothelium in eyes with keratoconus, but there is no common consensus on change in endothelial cell density (ECD) with studies showing variable results. PURPOSE This study aimed to compare and correlate endothelial cell parameters in different stages of keratoconus using specular microscope. METHODS This cross‐sectional, cohort, comparative study included 162 eyes of 96 patients with keratoconus in one or both eyes. Corneal endothelial cell parameters were assessed with SP‐1P specular microscope (Topcon Co., Tokyo, Japan). Corneal topography and thickness data were obtained from Sirius tomographer (Costruzione Strumenti Oftalmici, Florence, Italy). Eyes were divided into keratoconus stage 0 to 4 according to ABCD classification. Comparison and correlation of endothelial cell parameters in different stages were done. RESULTS There were 21.6% eyes (35) in stage 0, 29.6% eyes (48) in stage 1, 29.0% eyes (47) in stage 2, and 19.8% eyes (32) in stage 3 of keratoconus. Measurement was not possible in stage 4 keratoconus. Among the stages 0, 1, 2, and 3, the ECD was 3024, 3051, 3025, and 3043 cells/mm 2 ; coefficient of variation was 27.2, 27.6, 26.8, and 27.4; and frequency of hexagon cells was 61.5, 63.7, 63.3, and 62.3, respectively ( P >. 05). The number of analyzed cells was 232, 209, 185, and 169 in stages 0, 1, 2, and 3, respectively ( P <. 001). No significant difference was found in minimum, maximum, and average cell area between the stages ( P >. 05). A weak Spearman rank correlation of ECD, coefficient of variation, and frequency of hexagon cells was found between eyes with keratoconus stages 0 and 1 and stages 2 and 3 ( r = −0.05, P =. 65; r = −0.11, P =. 37; r = 0.05, P =. 67, respectively). No significant correlation was found in the number of cells analyzed and minimum, maximum, and average cell area between the stages ( P >. 05). CONCLUSIONS Endothelial cell parameters do not show any significant changes and correlation up to stage 3 of keratoconus in non–contact lens wearers.