Intravitreal versus posterior subtenon injection of triamcinolone acetonide for diabetic macular edema

Abstract

Purpose: To compare the short-term effects of intravitreal versus posterior subtenon injection of triamcinolone acetonide for diabetic macular edema.

Methods: This is a prospective and interventional study. Sixty eyes of 60 patients who had diffuse diabetic macular edema were assigned to receive a single intravitreal injection (4 mg) or a single posterior subtenon injection (40 mg) of triamcinolone acetonide. The central retinal thickness was measured using optical coherent tomography before injection and at 1 and 3 months after injection. Visual acuity and intraocular pressure (IOP) were also measured.

Results: Both intravitreal and posterior subtenon injections of triamcinolone acetonide resulted in significant improvements in visual acuity at 1 month and 3 months after injection. Both groups resulted in a significant decrease in central macular thickness (CMT) at 1 month and 3 months post-injection. IOP in the intravitreal injection group was significantly higher than in the posterior subtenon injection group at 3 months after injection.

Conclusions: The posterior subtenon injection of triamcinolone acetonide had a comparable effect to the intravitreal triamcinolone injection and showed a lower risk of elevated IOP. Posterior subtenon injection of triamcinolone acetonide may be a good alternative for the treatment of diffuse diabetic macular edema.

Fig. 1

Visual acuity in the intravitreal and posterior sub-tenon injected eyes at baseline and at 1 and 3 months after triamcinolone acetonide injection.

Fig. 2

Central macular thickness in the intravitreal and posterior subtenon injected eyes at baseline and at 1 and 3 months after triamcinolone acetonide injection.

Fig. 3

Changes in the OCT images of representative patient in the intravitreal and posterior subtenon injection groups. In an eye that underwent intravitreal injection, the marked macular edema (A) decreased substantially and the eye showed virtually normal macular configuration at 3 months (B) after injection. In an eye that underwent posterior subtenon injection, the macular edema (C) also decreased substantially with time, and the eye showed virtually normal macular configuration at 3 months (D) after injection.

Fig. 4

Intraocular pressure in the intravitreal and posterior subtenon injected eyes at baseline and at 1 and 3 months after triamcinolone acetonide injection.