436 BritishJournalofOphthalmology, 1991,75,436-437 Bilateral retinal artery occlusion due to

prolapse Br J Ophthalmol: first published as 10.1136/bjo.75.7.436 on 1 July 1991. Downloaded from

F van Rhee, T E Blecher, K A DeLepeleire, N R Galloway

Abstract arteriolar branches, leading to retinal oedema We report a case of bilateral retinal artery confined to the superotemporal quadrant. Field occlusion due to mitral valve prolapse. Most examination to confrontation of the left eye patients with retinal ischaemia in whom it is confirmed an inferior field defect, and on the found have not been previously known to have Amsler grid the patient could point out a dense it. Since it is a common condition itwould seem inferior scotoma. essential that it be included in the differential Physical examination revealed no evidence of diagnosis ofamaurosis fugax and retinal artery hypertension, subacute bacterial , or occlusion if future ischaemic events are to be carotid artery bruits. However, a midsystolic prevented. All patients with retinal ischaemia click followed by a late systolic murmur was should have a full cardiovascular examination heard at the apex. confirmed supplemented by echocardiography. the presence of thickened mitral valve leaflets, both of which prolapsed during (Fig 2). The left was dilated, but no thrombus was Several cardiovascular causes ofretinal ischaemia found (Fig 3). A 12-lead electrocardiogram have been described including rheumatic valvu- was normal, but 24-hour electrocardiographic lar disease, calcified aortic disease, monitoring detected brief (less than 9 seconds) subacute bacterial endocarditis, valvular pros- asymptomatic episodes of atrial (150 theses, cardiac myxomata, and carotid artery beats perminute). Ultrasonography and Doppler atherosclerosis. Mitral valve prolapse (MVP) is studies ofthe neck revealed no significant athero- the commonest form of in matous disease of the carotid arteries. Labora- adults, and it has been increasingly recognised tory investigations showed Hb 14 5 g/dl, that it is associated with thromboembolism, leucocytes 9 5 x 109'/l, and platelets 400x 109/l. including embolic phenomena in the ophthalmic The erythrocyte sedimentation rate was 9 mm in circulation. MVP is easily missed, since these the first hour. Further laboratory studies includ- patients may have few cardiac symptoms or ing urea and electrolytes, liver function tests, physical signs. Patients with it may first present blood glucose, autoantibody screen, serum pro- with amaurosis fugax or rarely retinal artery tein electrophoresis, platelet function tests, http://bjo.bmj.com/ occlusion, and awareness of the disease is there- triglycerides, and cholesterol gave results within fore important to the ophthalmologist. We normal limits. describe here a patient with bilateral retinal Treatment was instituted with and artery occlusion due to idiopathic prolapse ofthe . Her visual acuity has not improved, but mitral valve. she has so far had no further episodes ofcerebral or retinal ischaemia. on September 28, 2021 by guest. Protected copyright. Case report A 69-year-old woman presented with sudden Discussion painless loss ofvision ofthe right eye followed six The incidence ofMVP in the general population hours later by diminished vision in the infero- is 2 5% to 5%.' Although it was initially thought nasal field ofthe left eye. There was no previous to be a benign disorder, it has now been associ- history oftransient ischaemic attacks, amaurosis ated with subacute bacterial endocarditis, mitral fugax, or . She denied having had , dyspnoea, or . Essential thrombocythaemia had been diagnosed 10 years previously and was successfully treated with a single dose ofradioactive phosphorus. Her plate- Queen's Medical Centre, let count had remained normal since. Nottingham Ocular examination showed a dense relative Department of Haematology right afferent pupil defect with no light percep- F van Rhee tion in the right eye and 6/9 vision in the left. T E Blecher Funduscopy revealed occlusion of the central Department of retinal artery in the right eye due to a white Ophthalmology refractile embolus lodged at the disc centre. K A DeLepeleire Severe retinal oedema with a cherry red spot in N R Galloway the macula and supramacular haemorrhages Correspondence to: Dr F van Rhee, Department were noted, while the peripheral retina had a of Haematology, Queen's normal non-ischaemic appearance (Fig 1). The .S:s...... Medical Centre, Nottingham embolus at the disc did not glisten with arterial NG7 2UH. Figure 1: Refractile embolus lodged in right central retinal Accepted for publication pulsation or change position. In the left fundus artery. Cherry red spot and supramacular haemorrhages 6 December 1990 an embolus was present in one of the superior noted. Bilateral retinal artery occlusion due to mitral valve prolapse 437

,zr..

...... : Br J Ophthalmol: first published as 10.1136/bjo.75.7.436 on 1 July 1991. Downloaded from

Figure 3: Chest x ray showing bulging ofthe left heart border Figure 2: 2D - due to enlargement ofthe left atrium. Echocardiogram. Prolapse ofboth mitral valve cusps regurgitation, atrial and ventricular dysrhyth- into the left atrium during mias, and sudden . Reported thrombo- systole. LA=left atrium. LV=left . embolic complications include transient Most patients with cerebral or retinal RV=right ventricle. ischaemic attacks, stroke, amaurosis fugax, and ischaemic attacks in whom MVP is found have MV=mitral valve. rarely retinal artery occlusion.2 Symptoms of not been previously known to have MVP.6 The MVP are atypical chest pain, palpitations, cardiovascular examination may be entirely , and dyspnoea. On a normal and the history negative.7 These patients characteristic mid systolic click followed by a late may first present to the ophthalmologist, and it is systolic murmur may be heard, while sitting, important that MVP should be included in the standing, and the Valsalva manoeuvre all accen- differential diagnosis of amaurosis fugax and tuate the murmur.3 Two-dimensional echo- retinal artery occlusion if further thrombo- cardiography confirms the diagnosis. embolic episodes are to be prevented. All Our patient is unusual in having simultaneous patients presenting with retinal ischaemia should bilateral retinal artery occlusion, which strongly have a thorough cardiovascular assessment fol-

suggests a cardiac origin of the emboli. Retinal lowed by echocardiography. http://bjo.bmj.com/ examination revealed the typical calcific emboli 1 Levy D, Savage D. Prevalence and clinical features of mitral associated with valvular heart disease and sudden valve prolapse. Am Heartj 1987; 113: 1281-90. permanent loss of vision.4 Visual and neuro- 2 Barnett HJM, Boughner DR, Taylor DW, Cooper PE, Kostuk WJ, Nichol PM. Further evidence relating mitral valve logical dysfunction in essential thrombo- prolapse to cerebral ischaemic events. N Engl J Med 1980; cythaemia is associated with the presence 302: 139-44. 3 Devereux RB, Perloff JK, Reichek N, Josephson ME. Mitral of thrombocytosis and spontaneous platelet valve prolapse. Circulation 1976; 54: 3-14.

aggregation. Since both platelet count and 4 Young BR. The significance of retinal emboli. J Clin Neuro on September 28, 2021 by guest. Protected copyright. Ophthalmol 1989; 9: 190-4. platelet function were normal, it is unlikely that 5 Preston FE, Martin JF, Stewart RM, Davies-Jones GAB. essential thrombocythaemia should be Thrombocytosis, circulating platelet aggregates, and neuro- logical dysfunction. BrMedj 1979; ii: 1561-3. implicated as the cause of her emboli.' Ultra- 6 Barnett HJM. Embolism in mitral valve prolapse. Annu Rev sonography and Doppler flow studies of both Med 1982; 33: 489-507. 7 Wilson LA, Keeling PWN, Malcolm AD, Russell RWR, carotid arteries gave no evidence ofatheromatous Webb-Peploe MM. Visual complications of mitral leaflet plaques as a source ofemboli. prolapse. BrMedj 1977; ii: 86-8.