Work

Evaluation of the effect of subclinical hypothyroidism on retinal blood flow. OCT angiography study

Year: 2025

Type: article

Abstract: • Subclinical hypothyroidism is a thyroid hormone disorder that is identified by an elevated blood thyroid stimulating hormone (TSH) level and a normal blood free tetraiodothyronine (FT4) level. • Subclinical hypothyroidism may cause a decrease in blood flow especially in peripheral vessels due to bradycardia and predisposition to atherosclerosis. • The superficial retinal blood flow can be visualized non-invasively with optical coherence tomography angiography (OCT-A) within seconds. • A reduction in superficial retinal blood flow was observed in patients with subclinical hypothyroidism in the present study. • If our findings are supported by similar studies in the future, patient follow-up will be important in terms of retinal vascular disease and normotensive glaucoma development in patients with subclinical hypothyroidism. To evaluate retinal blood flow and retinal nerve fiber layer (RNFL) thickness in untreated subclinical hypothyroid patients by optical coherence tomography angiography (OCT-A). Forty-four eyes of 44 patients in the subclinical hypothyroidism group (SCHG) and 42 eyes of 42 healthy subjects in the control group (CG) were included in the study. Macular superficial retinal blood flow (SRBF), peripapillary RNFL thickness and optic nerve head cup to disk ratio (C/D) were measured and recorded by OCT angiography and compared between the patient and control groups. Correlation analysis between disease duration and SRBF and RNFL thickness was also performed. Mean SRBF was 37.23 ± 2.11 in the SCH group and 38.45±1.20 in the control group. Mean SRBF was significantly lower in the SCH group (p=0.003). Mean Peripapillary RNFL thickness was 98.18±7.77 in the SCH group and 100.07 ± 7.71 in control group. Peripapillary RNFL thickness was not significantly different between groups (p=0.290). There was no significant difference in mean C/D between the groups (p=0.708). Correlation analysis showed a moderate negative correlation between duration of disease diagnosis and SRBF in the SCH group (p<0.001, r=-0.564). There was also a weak to moderate negative correlation between disease duration and RNFL thickness in SCH group (p=0.002, r=-0.489). A reduction in SRBF was observed in patients with subclinical hypothyroidism. Additionally, a negative correlation was identified between disease duration and RNFL thickness. Patients with subclinical hypothyroidism should be monitored for potential retinal vascular disease and the development of normotensive glaucoma.

Source: Photodiagnosis and Photodynamic Therapy

DOI: 10.1016/j.pdpdt.2025.104530

Authors: Irfan Botan Gunes, Eda Demir Onal

Institution: Kocaeli Sağlık ve Teknoloji Üniversitesi

Language: English

Topic: Glaucoma and retinal disorders

Subfield: Ophthalmology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,610