How Radioactive Iodine Treatment Affects the Retina

Area of Science:

• Ophthalmology
• Endocrinology
• Nuclear Medicine

Background:

• Radioactive iodine (RAI) therapy is a standard treatment for hyperthyroidism and thyroid cancer.
• Potential ocular side effects of RAI therapy warrant investigation, particularly concerning retinal structures.

Purpose of the Study:

• To quantitatively assess macular and retinal nerve fiber layer (RNFL) thicknesses in patients undergoing RAI therapy.
• To evaluate the impact of RAI on retinal health in patients with hyperthyroidism and thyroid cancer.

Main Methods:

• Prospective study involving 40 patients (80 eyes) with hyperthyroidism or thyroid cancer receiving RAI therapy.
• Ophthalmological examinations and optical coherence tomography (OCT) measurements of macular and RNFL thickness were performed pre-RAI and at 1, 6, and 12 months post-RAI.
• Patients without pre-existing ocular pathology were included.

Main Results:

• No statistically significant differences were observed in macular thickness or RNFL thickness before and after RAI treatment in either the hyperthyroid or thyroid cancer groups.
• Age and sex distributions were comparable between the two study groups.
• No adverse effects on retinal layers were detected.

Conclusions:

• RAI therapy for hyperthyroidism and thyroid cancer does not appear to cause significant harm to the retinal layers.
• These findings suggest that RAI is a safe treatment modality concerning ocular structures like the macula and RNFL.