Regional Institute of Ophthalmology, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India.
Department of Refractive Surgery, Shree C. H. Nagri Eye Hospital, Ahmedabad, Gujarat, India.
Optom Vis Sci. 2021 Nov 1;98(11):1295-1298. doi: 10.1097/OPX.0000000000001805.
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.
This study aimed to compare and correlate endothelial cell parameters in different stages of keratoconus using specular microscope.
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.
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/mm2; 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).
Endothelial cell parameters do not show any significant changes and correlation up to stage 3 of keratoconus in non-contact lens wearers.
圆锥角膜的内皮变化很有意思，因为这些变化会影响手术方案的制定。以前，许多研究都评估了圆锥角膜眼中的内皮细胞，但对于内皮细胞密度（ECD）的变化没有达成共识，研究结果也存在差异。
本研究旨在使用共焦显微镜比较和分析不同阶段圆锥角膜的角膜内皮细胞参数。
这是一项横断面、队列、对照研究，纳入了 162 只眼的 96 例双眼或单眼圆锥角膜患者。使用 SP-1P 共焦显微镜（Topcon Co.，东京，日本）评估角膜内皮细胞参数。角膜地形图和厚度数据来自 Sirius 断层扫描仪（Costruzione Strumenti Oftalmici，佛罗伦萨，意大利）。根据 ABCD 分类，将眼分为圆锥角膜 0 期至 4 期。比较和分析不同阶段的内皮细胞参数。
圆锥角膜 0 期有 21.6%（35 只眼），1 期有 29.6%（48 只眼），2 期有 29.0%（47 只眼），3 期有 19.8%（32 只眼）。4 期圆锥角膜无法进行测量。在 0 期、1 期、2 期和 3 期，ECD 分别为 3024、3051、3025 和 3043 个细胞/mm2；变异系数分别为 27.2%、27.6%、26.8%和 27.4%；六角形细胞频率分别为 61.5%、63.7%、63.3%和 62.3%（P>.05）。0 期、1 期、2 期和 3 期分析的细胞数分别为 232、209、185 和 169 个（P<.001）。各期之间最小、最大和平均细胞面积无显著差异（P>.05）。在圆锥角膜 0 期和 1 期与 2 期和 3 期之间，ECD、变异系数和六角形细胞频率之间存在微弱的 Spearman 秩相关（r=-0.05，P=0.65；r=-0.11，P=0.37；r=0.05，P=0.67）。各期之间分析的细胞数、最小、最大和平均细胞面积无显著相关性（P>.05）。
在不戴隐形眼镜的情况下，圆锥角膜的内皮细胞参数在 3 期之前没有明显变化和相关性。
