Bilateral hypocalcemic cataract after total thyroidectomy in an Ethiopian young woman: Case report

Introduction: Hypocalcemia is a derangement in serum calcium level due to a vast spectrum of disorders, but the most common cause is surgery, usually thyroid gland surgery. Symptoms of Hypocalcemia can be due to increased neuromuscular excitation resulting in tetany, paresthesia or seizure. It can also be because of deposition of calcium in soft tissues producing reduced vision /cataract or calcification of basal ganglia. Cataract is the most common ocular symptom of hypocalcemia. Case report: A twenty six years old Ethiopian female patient presented with painless reduction of vision of both eyes 5 years after she was diagnosed to have hypocalcemia with very low serum calcium level (3mg/dl) due to damage to the parathyroid gland during total thyroidectomy for toxic goiter and has been on supplemental calcium gluconate twice daily. She had typical bilateral symmetrical posterior sub capsular cataract with punctate iridescent opacities in the anterior and posterior cortex of the lens. Systemic examination revealed horizontal surgical scar on the anterior neck and Positive Chvostek sign. Conclusion:The work up of bilateral symmetrical cataract in young patients should include serum electrolyte levels, particularly calcium, in those who had history of thyroid surgery. words:


Introduction
Thyrotoxicosis is a hyperthyroidism state where various symptoms occur due to a raised level of circulating thyroid hormones. There are four clinical types of the disease namely: diffuse toxic goiter (Graves' disease), toxic nodular goiter, toxic nodule, hyperthyroidism due to rarer causes.1 Diffuse toxic goiter and toxic nodular goiter with overactive inter-nodular tissue are treated with total thyroidectomy which cures by reducing the mass of overactive tissue.1 Total thyroidectomy is associated with complications such as: hemorrhage, airway obstruction and recurrent laryngeal nerve injury with voice change. Other complications include: thyroid insufficiency, recurrence of thyrotoxicosis and secondary hypoparathyroidism which is transient (can present within 2-5 postoperative days).1 Hypoparathyroidism occurs due to removal of the parathyroid glands or infarction through damage to the parathyroid end artery.1 Permanent hypoparathyroidism is not as 3 such common occurring in less than 1% of cases.1 It is associated with several systemic manifestations of hypocalcemia like tetany, confusion, muscle weakness and paresthesia.
Hypocalcemic cataract is one of the long term consequences of hypocalcemia along with papilloedema, basal ganglia calcification, nephrocalcinosis and prolonged QT interval.1, 2 We report a twenty six years old Ethiopian female patient with bilateral cataract with a history of previous thyroid surgery and systemic hypocalcemic symptoms and signs.

Case Report
A 26 years old female patient came to Jimma University department of ophthalmology (JUDO) with a compliant of bilateral painless and progressive reduction of vision of 2 years duration. She underwent total thyroidectomy seven years back for toxic diffuse goiter. A week after the surgery, she started to have circumoral numbness, paresthesia of the hands and legs, muscle cramp, stiffness of joints, mental confusion and irritability. Then she was diagnosed to have hypocalcemia due to damage to the parathyroid gland during the surgery and has been on supplemental calcium gluconate.
At the time of diagnosis her serum calcium level was very low (3mg/dl) and she was started on calcium gluconate supplement 500mg three times a day. Currently her serum calcium level raised to Other systemic Investigations revealed no remarkable finding (CBC was with in normal range; ESR 4 was 30mm/hr; FBS was 103mg/dl; VDRL and PIHCT were negative).
With the above findings she was diagnosed to have hypocalcemic cataract and we planned and counseled her to do phacoemulsification with PC-IOL. However the patient wanted to take some time to try alternative (religious) treatment. to hypocalcaemia presenting 4 years after total thyroidectomy.5 Our patient developed long-term hypocalcemia after total thyroidectomy which took longer time to return back to normal. Her serum calcium level at the time of diagnosis was very low. It took 7 years of treatment to raise her serum calcium level. Chronic hypocalcemia due to hypoparathyroidism is treated with calcium supplements (1000-1500 mg/d elemental calcium in divided doses) and either vitamin D2 or D3 (25,000-100,000 U daily) or calcitriol (1,25(OH)2D, 0.25-2 g/d). 2 The patient described here has been on calcium gluconate 500mg tid which is according to the recommended dose; was not taking vitamin D and calcitriol because they were not available in our setup and they are expensive to buy from abroad.

Conclusions
After thyroid surgery, permanent hypocalcemia should be considered as one of the long-term complications and patients should be followed for the symptoms of tetany and serum calcium levels.
The work up of bilateral symmetrical cataract in young patients should include serum electrolyte levels, particularly calcium, in those who had history of thyroid surgery. irrespective of the consent she has given. Written consent was obtained from the patient.

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None of the authors have any proprietary interests or conflicts of interest related to this submission.

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