Association between Thyroid Function and Ocular Parameters
by
, , , , and
Mirjana Babić Leko
1
,
Nikolina Pleić
1
,
Mladen Lešin
2,
Ivana Gunjača
1,
Vesela Torlak
3,
Jelena Škunca Herman
4,
Zoran Vatavuk
4,
Ante Punda
3,
Ozren Polašek
5,6,
Caroline Hayward
7 and
Tatijana Zemunik
1,* 1
Department of Medical Biology, School of Medicine, University of Split, 21000 Split, Croatia
2
Department of Ophthalmology, University Hospital of Split, 21000 Split, Croatia
3
Department of Nuclear Medicine, University Hospital of Split, 21000 Split, Croatia
4
Department of Ophthalmology, Clinical Hospital Sisters of Mercy, 10000 Zagreb, Croatia
5
Department of Public Health, School of Medicine, University of Split, Šoltanska 2, 21000 Split, Croatia
6
Algebra University College, 10000 Zagreb, Croatia
7
MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
*
Author to whom correspondence should be addressed.
Biology 2022, 11(12), 1847; https://doi.org/10.3390/biology11121847
Submission received: 31 October 2022
/
Revised: 5 December 2022
/
Accepted: 15 December 2022
/
Published: 18 December 2022
(This article belongs to the Section Medical Biology)
Simple Summary
The scope of this study was to determine if various ocular parameters are associated with parameters indicating thyroid activity. It is well-known that in some pathological thyroid conditions, the eyes can also be affected. Thyroid eye disease is the most extreme example of eye pathology caused by a pathological thyroid condition. In the current study, we measured the plasma levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), thyroglobulin (Tg), thyroglobulin antibodies (TgAb), and thyroid peroxidase antibodies (TPOAb), in addition to 20 ocular parameters in 4633 healthy adults (10 for each eye, including corneal radius, corneal thickness, anterior chamber depth, anterior chamber angle, lens thickness, posterior chamber length, axial length, intraocular lens power (IOL), spherical power, and cylinder power). This is, to the best of our knowledge, the largest study inferring the effect of thyroid activity on ocular parameters. The most important result of this study was that patients with hyperthyroidism had thicker corneas compared to euthyroid individuals. Intraocular lens power was increased in patients with clinical hypothyroidism, while spherical power was increased in euthyroid individuals with positive antibodies. The diagnostic potential of corneal thickness monitoring in patients with hyperthyroidism, which could indicate the later development of thyroid-related eye disease, should be explored in longitudinal studies.
Abstract
During development, thyroid hormones play an important role in eye development, while in adults, some pathological thyroid conditions can affect the normal functioning of the eyes. Thyroid eye disease is the most well-known eye pathology caused by a pathological thyroid condition. Few studies have investigated the association between ocular parameters and thyroid function. Thus, in this study, we aimed to examine whether thyroid activity affects ocular parameters. This cross-sectional study included 4633 healthy adults recruited within the 10,001 Dalmatians project of the Croatian Biobank. The plasma levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), thyroglobulin (Tg), thyroglobulin antibodies (TgAb), and thyroid peroxidase antibodies (TPOAb) were measured by an immunoassay. We determined 20 ocular parameters for each participant (10 for each eye, including corneal radius, corneal thickness, anterior chamber depth, anterior chamber angle, lens thickness, posterior chamber length, axial length, intraocular lens power (IOL), spherical power, and cylinder power). Patients with hyperthyroidism had thicker corneas compared to euthyroid individuals. Corneal thickness was also negatively associated with plasma TSH levels. Intra-ocular lens power was higher in patients with clinical hypothyroidism, while spherical power was higher in euthyroid individuals with positive antibodies compared to euthyroid individuals. Intra-ocular lens power negatively correlated with fT4 levels, while spherical power positively correlated with TgAb, TPOAb, and Tg levels and negatively correlated with TSH levels. The anterior chamber angle was positively associated with plasma TSH levels and TPOAb levels and negatively associated with plasma fT4 levels. These findings suggest an interesting interplay between ophthalmic measures and thyroid status, detectable even in the general adult population.
