Velázquez J S, Cavas F, Alió Del Barrio J, Fernández-Pacheco D G, Alió J
Department of Structures, Construction and Graphic Expression, Technical University of Cartagena, 30202 Cartagena, Spain.
Keratoconus Unit of Vissum Corporation Alicante, 03016 Alicante, Spain.
J Ophthalmol. 2019 Sep 22;2019:8731626. doi: 10.1155/2019/8731626. eCollection 2019.
Assessing changes suffered by the cornea as keratoconus progresses has proven to be vital for this disease diagnosis and treatment. This study determines the corneal biometric profile in eyes considered as affected by keratoconus (KC) showing severe visual limitation, by means of in vivo 3D modelling techniques. This observational case series study evaluated new objective indices in 50 healthy and 30 KC corneas, following a validated protocol created by our research group, which has been previously used for diagnosis and characterization of KC in asymptomatic (preclinical) and mild visually impaired eyes. Results show a statistically significant reduction of corneal volume and an increase of total corneal area in the severe KC group, being anterior and posterior corneal surfaces minimum thickness points the best correlated parameters, although with no discrimination between groups. Receiving operator curves were used to determine sensitivity and specificity of selected indices, being anterior and posterior apex deviations the ones which reached the highest area under the curve, both with very high sensitivity (96.7% and 90%, respectively) and specificity (94.0% and 99.9%, respectively). The results suggest that once severe visual loss appears, anterior corneal topography should be considered for a more accurate diagnosis of clinical KC, being anterior apex deviation the key metric discriminant. This study can be a useful tool for KC classification, helping doctors in diagnosing severe cases of the disease, and can help to characterize corneal changes that appear when severe KC is developed and how they relate with vision deterioration.
随着圆锥角膜病情进展评估角膜所遭受的变化，已被证明对该疾病的诊断和治疗至关重要。本研究借助体内三维建模技术，确定了被认为患有圆锥角膜（KC）且存在严重视力受限的眼睛的角膜生物特征轮廓。这项观察性病例系列研究按照我们研究小组制定的经过验证的方案，对50只健康角膜和30只圆锥角膜进行了评估，该方案此前已用于无症状（临床前期）和轻度视力受损眼睛的圆锥角膜诊断和特征描述。结果显示，在严重圆锥角膜组中，角膜体积有统计学意义的减少，角膜总面积增加，角膜前表面和后表面的最小厚度点是相关性最好的参数，尽管两组之间没有区分度。使用接受者操作曲线来确定所选指标的敏感性和特异性，前顶点和后顶点偏差是曲线下面积最高的指标，敏感性（分别为96.7%和90%）和特异性（分别为94.0%和99.9%）都非常高。结果表明，一旦出现严重视力丧失，应考虑角膜前表面地形图以更准确地诊断临床圆锥角膜，前顶点偏差是关键的判别指标。本研究可为圆锥角膜分类提供有用工具，帮助医生诊断该疾病的严重病例，并有助于描述严重圆锥角膜发生时出现的角膜变化以及它们与视力恶化的关系。
