Clinical Study on the Differential Diagnosis of High Myopia Astigmatism and Subclinical Keratoconus in Adolescents by Pentacam Anterior Segment Analyzer

To explore the clinical value of Pentacam anterior segment analyzer in differential diagnosis of high myopia astigmatism and subclinical keratoconus in adolescents. The study included 100 teenagers with ophthalmic diseases treated at our hospital between July 2015 and August 2021, including 58 individuals with simple high myopia astigmatism (73 eyes in the simple high myopia astigmatism group) and 42 teenagers with subclinical keratoconus (51 eyes in the subclinical keratoconus group). The corneal parameters of the two groups were measured with a Pentacam anterior segment analyzer, and we compared the thinnest corneal thickness, anterior (posterior) vertex height of the thinnest point of the cornea, index of vertical asymmetry (IVA), index of height descent (IHD), and the average corneal pachymetric progression index. The receiver operating characteristic curve (ROC) was drawn to evaluate the value of various parameters and combined diagnostic factor Y in the differential diagnosis of high myopia astigmatism and subclinical keratoconus. The thinnest region of the cornea in the subclinical keratoconus group was less than that in the simple high myopia astigmatism group, while the anterior (posterior) vertex height of the thinnest point of the cornea, index of vertical asymmetry (IVA), index of height decentration (IHD), and average corneal pachymetric progression index were higher than those in the simple high myopia astigmatism group (P < 0.05). For the differential diagnosis of high myopia astigmatism and subclinical keratoconus, the combined diagnostic factor Y, anterior (posterior) vertex height, IVA, IHD, and mean corneal progression index were 0.808, 0.833, 0.868, 0.847, 0.684, and 0.926 (P < 0.05). The AUC of the combined diagnostic factory was the largest, which was significantly different from that of the anterior vertex height of the thinnest point of the cornea (Z = 3.280), the posterior vertex height of the thinnest point of the cornea (Z = 3.205), IVA (Z = 2.764), IHD (Z = 2.237), and the average corneal progression index (Z = 4.125) (P < 0.05). Using the Pentacam anterior segment analyzer, differential diagnoses can be made for high myopia, astigmatism, and subclinical keratoconus.