Bilateral acute angle closure glaucoma and hyponatraemia: case reportA 65-year-old woman developed bilateral acute angle closure glaucoma and hyponatraemia during treatment with chlortalidone for hypertension.The woman presented to the emergency department with three days of sudden onset bilateral eye pain and blurry vision that occurred upon waking, associated with headache and nausea. Her medical history was significant for hypertension and hyperlipidaemia and she had been receiving chlortalidone [chlorthalidone; route and dosage not stated], atenolol and lisinopril. She did not have any respiratory symptoms. However, her family members had been experiencing fever, cough, fatigue and myalgias during the last 2 weeks. She was hospitalised. On initial examination, her best corrected visual acuity (BCVA) was 20/300 in the right eye and 20/200 in the left eye. Her both pupils were mid-dilated and nonreactive. Intraocular pressure (IOP) was 50mm Hg in both eyes. Slit-lamp examination showed microcystic corneal oedema in both eyes. Also, both anterior chambers were noted to be shallow centrally with a 1+ cellular reaction and a convex iris configuration. Trace nuclear sclerotic cataracts were observed. Gonioscopy of both eyes revealed a closed iridocorneal angle in all quadrants. An examination of the posterior segment revealed clear vitreous bilaterally, healthy optic nerves with a 0.2 vertical cup-to-disc ratio, flat maculas and normal peripheral retinas without visible choroidal effusions.The woman was started on acetazolamide, pilocarpine and unspecified topical aqueous suppressants for presumed bilateral acute primary angle closure with pupillary block. Her sodium level was noted to be 118 mmol/L, consistent with severe hyponatraemia. Additionally, she was diagnosed with COVID-19 infection. Immediately, she was escorted back to the emergency department for electrolyte management. As per the nephrology team, her low sodium was due to hypovolaemia from emesis and decreased oral intake in the setting of chlortalidone use. Her bilateral acute angle closure glaucoma was also attributed to chlortalidone [duration of treatment to reactions onset not stated]. Her IOP measured after 1h was 27 and 24 in the right and left eyes, respectively. However, her pupillary findings were unchanged. Pressures were maintained in both eyes with topical therapy and an improvement was noted in her symptoms. Chlortalidone was discontinued. She was treated with normal saline [sodium chloride] leading to improvement in her serum sodium level. Early in the following week, she was brought to the eye clinic, where she reported eye pain in the right eye worse than left. Also, she refused her eye drops and her IOP was noted to be elevated in both eyes. Iridotomies were performed; however, it was unsuccessful due to a limited view through corneal oedema. The pressures were able to be reduced acutely with medical therapy alone. Iridotomies were not re-attempted considering active COVID-19 infection. Over the next several days, the pressures were ...