Purpose : To evaluate the intraocular pressure (IOP) rising effect of anterior versus posterior
subtenon injection of triamcinolone in eyes with retinal vein occlusion

Methods : This prospective nonrandomized study was performed on 57 eyes of 57 patients with macular edema due to retinal vein occlusion. 26 eyes received posterior subtenon injection of 40 mg triamcinolone acetonide [PSTT] and 31 eyes received anterior subtenon injection of 40 mg triamcinolone acetonide [ASTT]. IOP measurement was performed before the injection, and after the injection at one week, two weeks, one month and every month up to six months after the injection. IOP rise was treated accordingly by drops and filtering surgery.

Results : IOP rise was found in 8% of the PSTT, and 67% of the ASTT injected eyes (P=0.001). All eyes with IOP rise in the PSTT group were controlled medically. Only 50% of eyes with IOP rise in the ASTT group could be controlled medically and filtering surgery was necessary for 33% of patients in the ASTT group. Visual acuity (VA) improvement was the same for both groups.

Conclusion : More patients may have IOP rise after ASTT injection compared to PSTT injections.