Early Effects of Intravitreal Triamcinolone on Macular Edema : Mechanistic Implication

PurposeTo evaluate the early effects of intravitreal triamcinolone acetonide (TA) on cystoid macular edema associated with retinal vein occlusion and diabetic retinopathy.DesignProspective, interventional, small case series.ParticipantsFour patients with cystoid macular edema resulting from retinal vein occlusion or diabetic retinopathy of more than 4 months’ duration and evaluated as suitable for treatment with intravitreous injection of TA.MethodsAfter ophthalmic examination, including visual acuity assessment, intraocular pressure (IOP) measurement, and optical coherence tomography (OCT) analysis, the patients received a single intravitreal injection of 4 mg TA. After the injection, consecutive visual acuity assessment, IOP measurement, and OCT analysis were performed after 1 hour, 6 hours, 1 week, and 2 weeks.Main Outcome MeasureOptical coherence tomography assessment of macular thickness.ResultsMacular thickness and edema initially were reduced as early as 1 hour after TA injection. A further continuous decrease was observed during the 2 weeks after treatment.ConclusionsThis rapid effect of intravitreal TA is interpreted to indicate that nongenomic effects on retinal or retinal pigment epithelial cell membranes, or both, may be responsible for this phenomenon. Identifications of these mechanisms may help design alternative, more specific drugs for the treatment of macular edema.