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Streptokinase, a commonly used thrombolytic agent, is a nonenzymatic protein produced by beta-haemolytic streptococci. It has been associated with several allergic reactions including bronchospasm, urticaria and anaphylaxis.1 We report an unusual case of bilateral uveitis with hypopyon following streptokinase therapy for myocardial infarction (MI).

Case report

A 74-year-old Caucasian gentleman was admitted with acute central chest pain of 3 hours duration and electrocardiogram was diagnostic for an anterior MI. Immediate medical management involved intravenous diamorphine 5 mg and cyclizine 50 mg. He was subsequently thrombolysed with 1.5 million units of intravenous streptokinase. Within 24 hours of receiving treatment, he had developed bilateral sore red eyes and reduced vision, worse in his left eye. However, he was only referred to the ophthalmology department 72 hours later, by which time his cardiovascular status had been stabilised and his ocular symptoms had actually begun to improve.

His past ocular history was significant for mild left amblyopia, ocular hypertension and bilateral retinoschisis. Best corrected visual acuity (BCVA) was 6/9 in the right eye (RE) and counting fingers in the left eye (LE). Ocular examination revealed bilateral conjunctival injection and anterior uveitis with hypopyon. The hypopyon measured 0.8 mm RE and 2 mm LE. Intraocular pressures were 22mmHg RE and 24mmHg LE. The vitreous in his RE was quiet and the fundus showed inferotemporal retinoshisis, but there was no fundus view of his LE. Ultrasound examination of his LE showed no signs of inflammatory activity. The patient had no clinical signs or symptoms of systemic vasculitis and no previous history of allergies. He was treated with intensive topical steroids and cycloplegics to which he had a prompt response and his BCVA improved to 6/6 RE, 6/12 LE by the second day of treatment. He subsequently made a complete visual recovery by the fourth week of treatment and his BCVA was 6/6 RE and 6/9 LE.

Comment

So far, seven cases of acute anterior uveitis following streptokinase therapy have been reported to the Committee on Safety of Medicines (personal communication). Of these, only one case had bilateral hypopyon.2 The pathogenesis of streptokinase-induced uveitis is most likely because of an immune complex hypersensitivity reaction, and not because of any specific toxicity to the eye.3 It could possibly be related to the individual's previous exposure to streptococcal antigens. Streptokinase may also be associated with other immunological reactions such as serum sickness4 and Guillain–Barre syndrome.5

Apart from streptokinase, this gentleman also had diamorphine and cyclizine as part of his immediate medical treatment. Ocular side effects of these drugs include miosis for diamorphine and nonspecific blurred vision for cyclizine. However, anterior uveitis is not a recognised or reported side effect of either of these drugs. Hence, streptokinase was thought to be the most likely culprit in this case. Other causes of acute bilateral hypopyon include Behcet's disease, HLA B-27 positive status and endogenous endophthalmitis.

The widespread use of streptokinase as a thrombolytic agent could lead to an increased incidence of this immunological phenomenon. Therefore, it is important for ophthalmologists to recognise this unusual ocular hypersensitivity reaction, so that it will be managed appropriately and any unnecessarily invasive management such as the use of intravitreal or intracameral antibiotics will be avoided.