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A 61 year old woman with asymptomatic aortic stenosis underwent elective left and right heart catheterisation for preoperative haemodynamic and angiographic assessment. Prior transthoracic echocardiogram had shown a peak pressure gradient across the aortic valve of 80 mm Hg. Transoesophageal echocardiography confirmed the presence of a bicuspid aortic valve with mild calcification. The left and right coronary arteries were angiographically normal. Repeated attempts at crossing the aortic valve with a conventional 6 French gauge pigtail catheter and subsequently a 6 French gauge Judkins right coronary artery catheter were unsuccessful.
During the procedure, the patient noted the abrupt onset of a left central scotoma that prompted referral for ophthalmological assessment. On examination the left visual acuity was reduced to 6/60. Fundal examination showed central retinal pallor (fig 1A) corresponding to the field defect with two white, non-refractile emboli in the branch retinal artery (fig 1B). This appearance is consistent with both calcific and platelet-fibrin emboli.
Retinal infarction is a rare complication of diagnostic coronary angiography although clinically inapparent cerebral infarction is recognised by magnetic resonance imaging in up to one fifth of patients with aortic stenosis in whom the valve is crossed by a cardiac catheter. The retinal circulation has a paucity of anastomoses and is thus very vulnerable to ischaemia. Although no single universally effective treatment exists, ocular massage, oral acetazolamide, anterior chamber paracentesis, and 95% oxygen with 5% carbon dioxide inhalation therapy can be tried in the acute phase to clear the obstruction before irreversible damage occurs. Branch retinal artery occlusions have a better prognosis than central retinal artery occlusions but a fixed visual field defect is usual. This case highlights the need for prompt recognition and urgent referral of any patient with visual symptoms during cardiac catheterisation, while once again questioning the safety of measurement of peak to peak gradient in assessment of the severity of aortic stenosis.