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Tuberculosis remains a major international public health concern, with the global incidence rate increasing approximately 0.4% per year, but much faster in sub‐Saharan Africa and Eastern Europe;1 the effect that HIV has on incidence is also highly significant.2 Within the UK the incidence of tuberculosis varies considerably between regions and ethnic groups, with rates increasing significantly among recent immigrants.3
This case describes a patient who presented with central retinal vein occlusion (CRVO) who was subsequently diagnosed with tuberculosis.
A 28‐year‐old Asian woman presented with transient obscuration of her vision. She had no other eye symptoms, central nervous system or systemic symptoms. She had no history of fevers or night sweats. There were no respiratory symptoms. There was no past medical history. She had lived in the United Kingdom for 18months and had an apparently normal chest X‐ray in her home country before leaving to come to the United Kingdom. She was a non‐smoker with no significant family history of illness.
On examination she was thin but she did not report significant weight loss. There were small lymph nodes in her left cervical chain. Fundoscopy revealed CRVO (see fig 11).). Initial investigations showed normal urea and electrolytes, white cell count of 6.4 109 cells/l, haemoglobin 12.2 g/dl, platelets 318, normal clotting screen, C‐reactive protein 3.6 mg/l, erythrocyte sedimentation rate 38 mm/hour, total protein was elevated at 87 g/l, plasma viscosity was elevated at 1.95 pa/s, IgG was 20.51 g/l. She had negative results for the following: rheumatoid factor, anti‐nuclear antibody, lupus anti‐coagulant, IgG and IgM phospholipid antibody, neutrophil cytoplasmic antibody (both anti‐proteinase cytoplasmic and myeloperoxidase perinuclear antineutrophil cytoplasmic antibody), and cryoglobulins. Complement C3 and C4 levels were normal.
Chest X‐ray showed very faint inflammatory shadowing in the left apex and a bulge in the contour of the right hilum possibly representing lymphadenopathy. She had a normal magnetic resonance imaging brain scan. A computed tomography scan of the abdomen and thorax (fig 22)) was performed that showed significant lymphadenopathy in the cervical and supraclavicar region as well the right hilum, subcarinal and paratracheal regions. The subcarinal lymph nodes were heavily calcified. There were ‘tree in bud' opacities in the apical segments of the upper lobes, suggestive of active pulmonary tuberculosis.
She had a bronchoscopy as she was unable to expectorate sputum. Bronchoscopic washings of the upper lobes showed scanty acid‐fast bacilli. Fully sensitive Mycobacterium tuberculosis grew from the culture. This confirmed the diagnosis, central retinal vein thrombosis associated with active tuberculosis. She has made a full recovery on quadruple antituberculous therapy, with resolution of her eye symptoms.
In this case symptoms were caused by non‐ischaemic CRVO, which on its own does not lead to blindness and carries a good prognosis. Ischaemic CRVO, however, is the second commonest sight‐threatening vascular disorder; the pathogenesis remains unclear.4 The commonest associations are hypertension, diabetes mellitus, bleeding or clotting disorders, autoimmune conditions, glaucoma, head trauma or excess alcohol consumption. Many other aetiologies have, however, been reported including secondary to excess liquorice ingestion, renal cell carcinoma, multiple myeloma, herpesvirus 6, drugs (including sildenafil and rofecoxib) and as a result of paraneoplatic phenomenon associated with lung cancer.
A retrospective study of 103 cases of CRVO in young adults without diabetes who were followed for at least six months showed the majority (64%) to be men. Although vision was good approximately a third had vision of 20/200 or worse.5 In a series of 17 young UK patients with CRVO, ocular involvement was characteristically unilateral, with moderate degrees of retinal haemorrhage, little retinal ischaemia, and a tendency to optic disc swelling. Visual prognosis was found to be good and follow‐up showed that most patients had good general health and no involvement of the other eye. Interestingly, an inflammatory aetiology or underlying vascular disease was not found in most patients.6
Tuberculosis associated with retinal vasculitis has been reported previously7 more than 20 years ago, although there was no evidence of vasculitis here. This case highlights the fact that CRVO can occur as a result of tuberculosis and transient visual disturbance should be appropriately investigated. With the increase in the incidence of tuberculosis, it is important to include it in the differential diagnosis list for CRVO.
Competing interests: None.