Orbital infection following posterior subtenon triamcinolone injection

Editor, Intravitreal injections of triamcinolone acetonide (TA) have been used to treat ocular manifestations caused by various disorders, including macular oedema (Jonas 2005; Sivaprasad et al. 2006) and choroidal neovascularization (Kojima et al. 2006). Refractory uveoretinitis, including that associated with Bechet's disease, is also a good indication for intravitreal injections of TA (Ohguro et al. 2006). Posterior subtenon TA injections are occasionally used because intravitreal injections of TA can cause microbial endophthalmitis at rates of 0.45–0.87% (Moshfeghi et al. 2003; Nelson et al. 2003). Infections from posterior subtenon TA injections seem to be rare: a Medline search extracted only one case report of an orbital abscess following a posterior subtenon TA injection (Engelman et al. 2004). We present a subject with Bechet's disease, who developed an orbital infection after a posterior subtenon TA injection. A 50-year-old man presented with blurred vision in his left eye and was found to have uveoretinitis as the result of an attack of Bechet's disease. He had a > 10-year history of repeated and refractory uveoretinitis caused by Bechet's disease and also had poorly controlled diabetes mellitus. He had been taking prednisolone (7.5 mg/day), aspirin (100 mg/day) and a topical steroid (0.1% betamethasone) for Bechet's disease for ≥ 3 years. A posterior subtenon TA injection was performed in the clinic to treat the uveoretinitis. After topical anaesthesia and levofloxacin, the superotemporal conjunctiva was incised, and 12 mg of TA (Daiichi-Sankyo, Tokyo, Japan) was injected into the posterior subtenon space. Topical povidone-iodine was not used. After the injection, topical colistin sodium methanesulphonate (four times/day) was prescribed. Two weeks later, the patient noticed a discharge from his left eye and returned to the clinic. His conjunctiva was congested and oedematous with discharge at the injection site. Minocycline hydrochloride (200 mg/day) was prescribed and the symptoms gradually improved. However, 1 month later, the congestion and oedema of the conjunctiva worsened, and the patient was referred to our clinic. His best corrected visual acuity was 20/100 OD and 20/200 OS. The upper and lower lids and conjunctiva of the left eye were swollen and congested, and a whitish mass was seen at the superotemporal region. Because the infection had been refractory to topical and systemic antibiotics, the atrophic superotemporal conjunctiva was incised, and the yellowish-white discharge washed out with balanced salt solution containing 1% vancomycin and 2.5% povidone-iodine solution. After the surgery, topical levofloxacin, cefmenoxime hemihydrochloride (six times/day) and minocycline hydrochloride (200 mg/day) were prescribed. Microbiological cultures of the conjunctiva identified Nocardia species. The symptoms gradually decreased, but, 6 weeks later, they worsened again. Two more similar treatments were necessary to eliminate the symptoms completely. No recurrences were observed in the 10 months thereafter. Nocardia sp. are aerobic, gram-positive, filamentous bacteria found in soil. They can be contracted by inhaling contaminated dust or by contamination of a wound with soil containing Nocardia. Although Nocardia can cause infection in healthy persons, it mainly affects immunocompromised hosts, such as patients on chronic steroid therapy or those undergoing cancer treatment. Typically, Nocardia infection has a late onset, and is chronic and indolent; its signs and symptoms are similar to those of low-virulence organisms (Haripriya et al. 2005). Our patient was on chronic systemic and local steroids for Bechet's disease. He also had poorly controlled diabetes mellitus. Our observations indicate that ophthalmologists should be aware that posterior subtenon TA injections can cause orbital infections, especially in subjects who are immunocompromised.