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Anterior ischaemic optic neuropathy (AION) and the need for its early diagnosis and treatment in temporal arteritis are well known especially because of the risk of bilateral blindness. Posterior ischaemic optic neuropathy (PION) is a rarer condition but has been described in systemic lupus erythematosus, polyarteritis nodosa, hypertension, diabetes, anterior carotid artery occlusion, blood loss, intraoperative hypotension, as well as temporal arteritis. We describe two cases of retrobulbar ischaemic optic neuropathy, one due to eosinophilic fasciitis and the other to Wegener's granulomatosis and discuss their presentation and management.
Case 1
An 87 year old woman, who was previously diagnosed with eosinophilic fasciitis, presented with acute visual loss of her right eye. Ten years earlier she had had a history of skin tightness and thickening affecting her arms, legs, and trunk but sparing her face. She had pain and swelling of her hands, early morning stiffness, but no Raynaud's phenomenon. Blood tests at the time showed an erythrocyte sedimentation rate (ESR) of 21 mm in the first hour, haemoglobin 12.7 g/dl, white cell count 7.6 × 109/l, of which 19% were eosinophils (1–6%). Eosinophilic fasciitis was diagnosed on the basis of her clinical picture and blood eosinophilia. She was also antinuclear antibody positive; anti-double stranded DNA antibodies, anti-neutrophil cytoplasmic antibodies (ANCA), and cardiolipin antibodies were negative and protein S and C normal and she had been started on prednisolone and aspirin. She had also had several transient ischaemic attacks involving the right side of her body with paraesthesia of her face, hand, and right foot, which lasted 5 minutes at a time. She had a history of hypertension treated with amilodipine and carotid ultrasonography demonstrated less than 40% carotid stenosis.
On presentation she had already had two painless episodes of clouding of vision with flashing lights and a shadow which cleared after a couple of hours on each occasion. On the third occasion she suddenly developed clouding of vision in her right eye which did not recover.
On examination her visual acuity was 6/18 right, 6/9 left. She had a right afferent pupillary defect, but no retinal abnormalities apart from drusen at the macula reflecting age related change. Similar changes, albeit less marked, were also present at the left macula. The right optic disc was normal but became pale later 2 months after the initial episode. Her ESR was 63 mm in the first hour and her long term steroids were increased from 5 mg to 30 mg of prednisolone and she continued on aspirin. She had no further episodes of visual loss and there was some improvement in the visual field.
Case 2
A 56 year old woman who had Wegener's granulomatosis was referred to the eye department with sudden loss of vision in her right eye. Her medical history included rheumatoid arthritis, secondary Sjögren's syndrome, vitiligo, and pernicious anaemia treated with vitamin B12 injections. She took ibuprofen and azathioprine for arthritis.
She had chronic sinusitis which became more severe over 3 months and had nose bleeds, facial pain, anorexia, and lost 1 stone (6.3 kg) in weight over 2 months. Blood tests showed she had a negative serum ACE, a positive c-ANCA, and a diagnosis of Wegener's granulomatosis was made after a nasal biopsy (Fig 1). She was started on intravenous cyclophosphamide 750 mg and intravenous methylprednisolone 1 g, and maintained on 40 mg of oral prednisolone.
Nasal biopsy (case 2) showing foci of necrosis surrounded by epithelioid histiocytes and giant cells typical of Wegener's granulomatosis (haematoxylin and eosin staining).
Following her second course of chemotherapy, while on holiday in Spain she noticed visual disturbances in her right eye and had a sudden loss of vision 2 days before her return. Visual acuity was hand movements in the right eye, 6/9 in the left eye. She had a right central scotoma to confrontation, a relative afferent pupil defect, and no proptosis. Intraocular pressures and funduscopy were normal with no optic disc swelling (Fig 2), ESR was 39. A computed tomography scan showed extensive inflammatory disease in the sinuses and anterior cranial fossa but no orbital masses or any other evidence of compression of the optic nerves or abnormality of the rest of the visual pathway. She had a third dose of intravenous cyclophosphamide 750 mg but unfortunately continued to lose vision rapidly. Two days later she had bare perception of light in both eyes and her pupils were unresponsive to light. She had a magnetic resonance imaging scan and the optic chiasm, intracranial, and orbital segments of the optic nerves appeared normal with the nerve sheaths a little prominent but no soft tissue mass in the orbits. Her clotting studies were normal and she was started on anticoagulants. She had four sessions of chemotherapy, intravenous cyclophosphamide 750 mg, and pulsed steroids as well as a 5 day course of intravenous immunoglobulin (found to be effective in refractory in Wegener's granulomatosis1). Though her upper respiratory symptoms improved there was no change in her vision and she remained with no perception of light in the right eye and bare perception of light in the left eye. The optic discs went on to become atrophic and electrodiagnostics showed normal electroretinograms with low amplitude visual evoked responses though normal latency.
Fundus photographs of case 2 (A) right eye and (B) left eye showing normal optic discs.
Comment
Both patients presented with posterior ischaemic optic neuropathy (PION) where there was visual loss, with signs of optic tract neuropathy but normal optic discs which later became atrophic. This condition was described by Hayreh,2 who in one study of 170 patients with giant cell arteritis found PION in 7%.3 There are no disc signs initially as the part of the optic nerve affected is posterior to the retrolaminar region and the blood supply is from the peripheral centripetal vascular system rather than the posterior ciliary artery circulation affected in anterior ischaemic optic neuropathy.
Eosinophilic fasciitis is a rare connective tissue disorder first described by Shulman in 1974,4 presenting with painful swelling and brawny induration of the limbs and trunk, characteristic histology with sclerosis and lymphocytic inflammation affecting the deep fascia, subcutaneous tissue, and a peripheral eosinophilia (often more than 7% of the differential WCC). More than 200 cases have been described5 and there may be haematological associations such as aplastic anaemia, thrombocytopenia, leukaemia, and myelodysplasia6; other associated systemic conditions such as arthritis, thyroid disorders, inflammatory bowel disease, hepatitis, pericarditis, pulmonary and pleural7 involvement have been described. There is often a good response to corticosteroids with 70% expecting improvement and remission in 15%.
The second case of PION continued to lose vision although she was already on steroids and chemotherapy. Wegener's granulomatosis is a rare multisystem disorder with a necrotising vasculitis which affects the upper respiratory tract and lungs. It may cause a glomerulonephritis and has ocular involvement in 40% of cases; which may be varied including conjunctivitis, episcleritis, scleritis, corneal ulceration, retinal vasculitis, orbital and lacrimal masses.8 One series of five patients with Wegener's granulomatosis described vasculitis of the temporal artery and overlapping features of giant cell arteritis with headaches, jaw claudication, and sudden visual loss.9 Optic neuropathy is usually related to pressure from an orbital granuloma or sinus disease. In case 2 there was no evidence of this and we felt this was due to retrobulbar vasculitic pathology. This is extremely rare; only two other cases have been reported in the literature.10 Our patient had rapidly sequential bilateral retrobulbar ischaemic optic neuropathy while she was on chemotherapy and steroids which were started before she had any visual symptoms. In a patient with Wegener's granulomatosis even when there is no evidence of optic nerve or chiasmal compression visual disturbance may herald this rare but devastating manifestation and should be treated aggressively.
Footnotes
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Case 2 has been presented as a poster at the Royal Society of Medicine Ophthalmic Trainees Meeting 8 June 2000 as Bilateral sequential retrobulbar optic neuropathy—a devastating complication of Wegener's granulomatosis.