Is keratoconus associated to thyroid diseases? Assessment of the corneal parameters in patients with congenital hypothyroidism

Purpose: To investigate the association between keratoconus and congenital hypothyroidism (CH). Patients and methods: Patients were enrolled in this study and divided into two groups. The first group comprised 31 subjects (11M:20F) with the mean age of 15.2 ± 3.9 years. affected by CH, and the control group was composed by 19 healthy individuals (8M:11F) aged 14.3 ± 4.6 years. All patients underwent complete ophthalmologic examination with visual acuity assessment, refraction, slit lamp examination, and retinoscopy. Corneal parameters were measured using Scheimpflug camera (Pentacam® Oculus, Germany). The main outcome measures considered for evaluation were: average corneal curvature (K), central corneal thickness (CCT), anterior elevation and posterior elevation at the thinnest point, corneal volume (CV), anterior chamber depth (ACD), and anterior chamber volume (ACV). Additionally, data from Belin/Ambrosio Enhanced Ectasia Display (BAD) and the high order aberrations were evaluated. Kolmogorov-Smirnov test was used to verify the Gaussian distribution, the comparison between the controls and cases group was performed by Mann-Whitney nonparametric test. A p value less than 0.05 was considered to be statistically significant. The odds ratio was performed in order to quantify the relationship between the congenital hypothyroidism and abnormal values displayed on front BAD. Results: The significant difference in the refractive status between both groups was observed. As to examined corneal and anterior chamber parameters no statistical differences were detected. Conclusions: Congenital hypothyroidism diagnosed and treated since the early postnatal life doesn't induce abnormalities of corneal parameters suggestive for keratoconus.