ABSTRACT
PURPOSE: To examine the clinical association between thyroid gland dysfunction and keratoconus. METHODS: This was a cross-sectional case-control study conducted between May 2018 and July 2019. After performing Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) examination, flat, steep, and maximum simulated keratometric readings were recorded for each patient. Serum concentrations of free triiodothyronine, free thyroxine, and thyroid-stimulating hormone were measured. Further examinations by an endocrinologist were indicated for patients with positive laboratory results to confirm thyroid gland dysfunction. RESULTS: One hundred eighty-seven patients with bilateral keratoconus and 187 sex- and age-matched healthy controls without keratoconus were analyzed. Mean age was 26.4 ± 8.2 years for the patients with keratoconus and 27.1 ± 9.4 years for the control patients, with no significant difference. The results showed that thyroid gland dysfunction prevalence was 10 of 187 patients with keratoconus (5.3%) and 2 of 187 control patients (1.1%), and the difference was statistically significant (P = .036). For the patients with keratoconus and thyroid gland dysfunction, 8 were women and 2 were men. Additionally, 6 patients (2 men and 4 women) had hyperthyrosis and 4 women had hypothyrosis. For controls, the two patients had hypothyrosis. CONCLUSIONS: This study showed that there is a possible association between keratoconus and thyroid gland dysfunction, but more studies are needed to build upon these results. [J Refract Surg. 2020;36(4):253-257.].
Subject(s)
Corneal Stroma/pathology , Corneal Topography/methods , Keratoconus/etiology , Thyroid Diseases/complications , Visual Acuity , Adult , Biomarkers/blood , Case-Control Studies , Corneal Pachymetry , Corneal Stroma/physiopathology , Cross-Sectional Studies , Elasticity , Female , Follow-Up Studies , Humans , Keratoconus/diagnosis , Keratoconus/drug therapy , Male , Prognosis , Retrospective Studies , Thyroid Diseases/blood , Thyrotropin , Tomography, Optical CoherenceABSTRACT
PURPOSE: To evaluate the optical value of a new model of intrastromal corneal ring segments (ICRS) (Keratacx Plus) in patients with keratoconus and to quantify subsequent changes in corneal topography and asphericity. SETTING: Private practice. DESIGN: Prospective case series. METHODS: This study comprised patients who had primary keratoconus or keratectasia after laser in situ keratomileusis (LASIK); none wore contact lenses. Rings were implanted through tunnels created manually or with a femtosecond laser. All eyes had clear visual axes and corneal thickness over 450 µm at the incision site. Preoperative and postoperative pachymetry images were acquired. Results were analyzed using a matched-pair t test and the Kolmogorov-Smirnov test. RESULTS: Twenty-nine eyes (24 patients; mean age 30.1 years ± 10.6 [SD]) were evaluated. The ICRS significantly increased uncorrected and corrected visual acuities from 0.05 to 0.16 and from 0.17 to 0.5, respectively (z = 4.7, P < .001). They reduced the median spherical error from -4.0 to -0.5 diopters (D) (P < .001) and median cylindrical error from -4.4 to -2.5 D (P < .001). All topographic parameters were reduced, including maximum keratometry (K) (49.4 D versus 45.1 D), minimum K (49.4 D versus 45.1 D), mean K (51.4 D versus 48.4 D), astigmatism (-2.0 D versus -0.5 D), and asphericity (eccentricity 0.49 versus 0.23) (all P < .001). CONCLUSIONS: The ICRS provided topographic and visual improvement in keratoconus and post-LASIK keratectasia. Variance in surgical outcomes with manual versus femtosecond tunneling and the effect of different ring sizes are yet to be studied.