Dear Editor

Sutter and Gillies described in their paper four cases of endophthalmitis-like reaction after an intravitreal injection of triamcinolone acetonide (Kenacort A-40, Bristol-Myers Squibb Pharmaceuticals, Australia) as a distinct clinical entity.[1] We would like to point out some issues that could help to explain their findings at least in part.

We strongly believe that the endophthalmitis-like reaction appeared as an acute reaction to the preservative of the drug (i.e. benzyl alcohol). Hida et al. found that the vehicle, and not the crystalline cortisone itself, could be toxic to the intraocular tissue.[2] Although no ocular toxicity has been proved in humans, intravenous use of solutions containing this alcohol are known to have caused a fetal toxic syndrome in premature infants.[3] Approximately 25 percent of all commercially available ophthalmic solutions are preserved with chlorobutanol. Benzyl alcohol is rarely used because of its low activity, irritation, and capacity for disolving polystyrene.[4] In fact, experience has demonstrated that many vehicles meet all the criteria to become a suitable one but do not have the proper feel to make them acceptable to the human patient.

On the other hand, the authors stated that the site of injection was at the superior-temporal quadrant. It is well-known that this injection method will completely obscure the view of the fundus and increase the vitreous reaction (i.e. injected suspension will drop from up to down throughout the vitreous gel).

We recommend the use of triamcinolone acetonide suspension for intravitreal injection with most of the vehicle removed as suggested by others.[5] We also suggest the introduction of the needle into the eye at the inferior-temporal quadrant in an effort to keep the suspension in the inferior vitreous region to reduce the vitreous reaction, and out of the visual axis.

References

(1) Sutter FKP, Gillies MC. Pseudo-endophthalmitis after intravitreal injection of triamcinolone. Br J Ophthalmol 2003; 87:972-974.

(2) Hida T, Chandler D, Arena JE, Machemer R. Experimental and clinical observations of the intraocular toxicity of commercial corticosteroid preparations. Am J Ophthalmol 1986;101:190-195.

(3) Brown WJ, Buits NR, Cory Gipson,HT, Huston RK, Kennaway NG. Fatal benzyl alcohol poisoning in a neonatal intensive care unit. Lancet 1982;1(8283):1250.

(4) Mullen W, Shepherd W, Labovitz J. Ophthalmic preservatives and vehicles. Surv Ophthalmol 1973;17(6):469-483.

(5) Jonas JB, Hayler JK, Söfker A, Panda-Jonas S. Intravitreal injection of crystalline cortisone as adjunctive treatment of proliferative diabetic retinopathy. Am J Ophthalmol 2001;131:468-471.