AIM: To analyze the diagnostic value of Pentacam anterior segment analyzer examination parameters on early keratoconus.

METHODS: Retrospective control study. Totally 100 patients(124 eyes)with keratoconus who were treated in the hospital between January 2019 and January 2020 were selected as study group. According to the severity of Amsler-Krumeich classification, patients with keratoconus were divided into mild group(51 eyes), moderate group(43 eyes)and severe group(30 eyes), and another 30 normal people with past history of myopia and astigmatism(30 eyes)were selected as control group. The Pentacam anterior segment analyzer parameters \〖horizontal central curvature of 3mm diameter range(K1), vertical central curvature of 3mm diameter range(K2), maximum refractive power of corneal anterior surface(Kmax), corneal astigmatism(Cyl), corneal thickness at the thinnest(thinnest local), ROC curve was used to analyze the sensitive indicators in the diagnosis of early keratoconus.

RESULTS:The K1, K2, Kmax, Cyl, ISV, IVA, KI and ACD in study group were significantly higher than those in control group(P<0.05)while the thinnest local and ACV were significantly lower than those in control group(P<0.05). There were statistically significant differences in the K1, K2, Kmax, Cyl, thinnest local, ISV, IVA, KI, ACV and ACD among patients with different degrees of keratoconus(P<0.05), and the K1, K2, Kmax, Cyl, ISV, IVA, KI and ACD in moderate group and severe group were significantly higher than those in mild group(P<0.05)while the thinnest local and ACV were significantly lower than those in mild group(P<0.05), and there were significant differences in the parameters between moderate group and severe group(P<0.05). ROC diagnostic curve results showed that Kmax, thinnest local, ISV, IVA and KI were sensitive indicators for diagnosing keratoconus(AUC>0.85), of which ISV had the highest diagnostic value.

CONCLUSION: Pentacam anterior segment analyzer can effectively measure the keratoconus parameters. There are differences in the parameters among patients with different degrees of keratoconus. Kmax, thinnest local, ISV, IVA and KI are sensitive indicators for diagnosing early keratoconus, and Pentacam anterior segment analyzer examination parameters have a higher diagnostic value on early keratoconus.