Corneal Topography Findings Among Patients With Thyroid Dysfunction

The aim of this study was to compare and evaluate changes in corneal topography and biomechanics among patients suffering from various forms of thyroid gland dysfunction

Endocrinology Clinic at the Faculty of Medicine, Alexandria University. 

topography and Scheimpflug imaging were performed using TMS (Tommey GmbH) to measure flat (K1), steep (K2), and maximum (K max) simulated keratometry readings, along with minimal corneal thickness. Additionally, serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were measured for all participants.

The study population consisted of 137 females and 63 males with a mean age of 32.4 ± 8.2 years. The mean K1 was 45.86 ± 4.69 D, the mean K2 was 47.89 ± 5.08 D, and the mean central corneal thickness (CCT) was 475 ± 0.36 µm. These results indicated thinner and steeper corneas than age-matched normative databases. However, no statistically significant correlation was found between these topographic parameters and serum TSH, FT4, or FT3 levels. While one case of iatrogenic post-LASIK ectasia was identified, no cases of true keratoconus were reported in this specific series.

Patients with thyroid dysfunction demonstrate significant topographic changes characterized by steeper and thinner corneas, though these did not manifest as clinical keratoconus in this study. Consequently, cautious analysis of corneal topography is critical for these patients, especially when screening for refractive surgery.