An immunocompetent 26-year-old Phillipino man living in regional Australia was diagnosed with active pulmonary tuberculosis and was commenced on ATT consisting of 2 months of ethambutol and pyrazinamide with 6 months of isoniazid and rifampicin (2HRZE/4HR). After 2 weeks of ATT, he presented to the local ophthalmologist for baseline ethambutol screening. At the time of review, he did not report any visual symptoms. Physical examination demonstrated visual acuity of 20/20 in each eye. Corneae and anterior chamber examination was normal. However, fundal examination revealed temporal blot haemorrhages and multiple inferior and superonasal nodules at the veins that were suspicious for occlusive retinal vasculitis (Fig. 1). Fundus fluorescein angiography (FFA) confirmed periphlebitis with staining of the vessel walls, and a secondary branch retinal vein occlusion (BRVO) with diffuse areas of capillary non-perfusion indicating retinal ischaemia (Fig. 2).
To combat the immunoreaction causing the vasculitis a systemic steroid is often used. In discussion with the treating respiratory physician, the use of systemic steroids was avoided to prevent immunosuppression in active tuberculosis. Instead, the off-label use of bevacizumab 4mg as an intravitreal injection (IVI) was utilised to provide localised treatment for the vasculitis. With the IVI, the periphlebitis and temporal haemorrhages were settling, however, extensive whitening of the retina developed from the BRVO. Sectoral scatter laser therapy was applied to the areas of retinal ischaemia to prevent extension and the risk of retinal detachment. Throughout this period, visual acuity remained normal and the patient asymptomatic.
Six weeks after the initiation of ATT, systemic steroids (1mg/kg) were initiated with gastric protection (pantoprazole 40mg). In the preceding reviews of the eye, peripheral whitening and vascular sheathing reduced but remained present until the cessation of the 6 months of ATT. There was a recurrence of retinal whitening and perivascular nodules when the prednisone dose was reduced after 3 weeks, but abated following medical retina subspecialty advice of a small increase in steroids and a prolonged wean. The slow wean of steroids was conducted over 4 months after the cessation of ATT. Over 28 months of follow-up there were no further recurrences of ocular inflammation or signs of vasculitis after completing the 9 months total of systemic steroids.