Sir,

Triamcinolone acetonide is a potent corticosteroid frequently used for the treatment of a variety of ocular inflammatory conditions. Numerous complications have been reported. We report a case of conjunctival ischaemia following posterior subtenon's triamcinolone acetonide for diabetic macular oedema. To the best our knowledge this has not been previously reported.

Case report

A 58-year-old male patient was seen in the retinal clinic. He was diagnosed with diabetes 16 years ago and was subsequently diagnosed hypertensive. He had bilateral cataract extractions with lens implants in the early 1990s and his best-corrected visual acuities were 6/4 OD and 6/6 OS. His medication included insulin, ACE inhibitors, and aspirin. There was no history of allergic reactions. He had focal argon laser treatment for clinically significant macular oedema (CSMO)—once to the right and three times to the left eye over a period of 30 months. His vision deteriorated to 6/18 OS and the macular oedema persisted despite laser treatment. Fluorescein angiography revealed florid macular oedema with no evidence of capillary nonperfusion. In all, 40 mg of triamcinolone acetonide was injected into the posterior subtenon's space superotemporally. At 2 weeks after the injection, a deposit of triamcinolone located anteriorly under the conjunctiva was evident (Figure 1). The overlying conjunctival vessels were obliterated, and showed no sign of perfusion until 3 months after the injection, when larger vessels were noted to appear superiorly (Figure 1). His vision has remained stable at 6/18 OS, with nonresolution of the macular oedema.

Figure 1
figure 1

Subconjunctival deposit of triamcinolone superotemporally. Early reperfusion of conjuctival vessels 3 months postinjection (black arrows).

Full size image

Comment

High-dose periocular corticosteroid injections are routinely used for the treatment of numerous inflammatory eye conditions.1, 2, 3, 4 They are commonly used in the management of intermediate or posterior uveitis and cystoid macular oedema. Different modes of administration of the injection have been described—orbital floor,4 posterior subtenon's and trans-tenon's retrobulbar infusions.3 The aim of these periocular injections is to deliver high doses of the drug locally, while reducing to a minimum unwanted systemic side effects. However, local complications do occur and many have been described—including: raised intraocular pressure, cataract progression, ptosis, retrobulbar haemorrhage, subconjuctival haemorrhage, globe perforation, retinal and choroidal vascular occlusions, and conjuctival ulceration.1, 2, 3, 4

The patient we describe had a localized collection of subconjunctival triamcinolone, associated with conjunctival vasculature nonperfusion. Glucocorticoids have been well documented to potentiate the vasoconstrictive effects of circulating catecholomines,5 which may be responsible for this area of focal conjunctival ischaemia. Another possibility could be a localized toxic reaction to the triamcinolone acetonide. At 3 months subsequent to the injection there appears to be superior reperfusion over this area, but the vessels appear larger than the surrounding normal conjunctival vasculature. No related complications have arisen from this.