Severe Ophthalmological Complications of Thyroid Disease are Rare in Ibadan, Southwestern Nigeria: Results of a Pilot Study

BACKGROUND Ocular manifestations of thyroid dysfunction constitute a wide clinical spectrum ranging from minor ocular discomfort, lid retraction, lid lag and ocular injection, to sight threatening eyeball protusion and optic nerve compression. Thyroid-related eye disorders are most commonly associated with Graves' disease, and this most frequently occurs in the setting of hyperthyroidism. However, in 10% of cases, typical eye signs have also been reported in euthyroid and hypothyroid states. The severity of thyroid eye disease has been linked to cigarette smoking. There is very little data specifically reporting the ocular manifestations of thyroid disease among black African patients and there is no known report from Nigeria. This pilot study therefore focused on documenting the ocular signs accompanying thyroid dysfunction in a black African population. AIM To evaluate the pattern of ocular complications, among patients treated for thyroid disorders, in a major Nigerian teaching hospital. RESULTS A total of 75 patients with thyroid dysfunction, were evaluated, comprising 63 females and 12 males. There was a very low prevalence of smoking among patients (<5%). Graves' disease was the commonest thyroid disorder, representing 70% of cases. Seventy-eight percent of patients were hyperthyroid, 11.8% were euthyroid and only 9.8% of patients were hypothyroid. Commonest systemic symptoms were neck swelling (68.6%), weight loss (63.8%), tremors (60.9%) and palpitations (59.4%). Two-thirds of patients reported ocular symptoms consisting mainly of painless eye swelling (66.7%) and ocular irritation (58%). Conjunctival injection, lid lag and lid retraction were the commonest ocular signs. Chemosis, severe proptosis and ocular motility disorder were very rare. Optic neuropathy was found in 4 patients but was related to pre-existing glaucoma. Majority of patients required only ocular emollients and tear supplements. CONCLUSION Severe ocular complications of thyroid disorders were uncommon in this cross-section of Nigerian patients. This may be linked to the very low prevalence of cigarette smoking among Nigerians or genetic and environmental factors linked to their African heritage.