To determine the preoperative factors of different types of diabetic macular edema (DME) classified using Optical Coherence Tomography (OCT) and to evaluate the short-term therapeutic effects and pattern changes of intravitreal triamcinolone acetonide injection (IVTA).

Seventy-seven eyes of 60 patients, who had been previously diagnosed with DME through fundoscopy and fluorescein angiography, were enrolled, and each patient was classified as one of three DME types according to his/her OCT features: Type 1, diffuse retinal thickening; Type 2, cystoid macular edema; and Type 3, serous macular detachment. We compared age, sex, the duration of diabetes mellitus (DM), and decreased visual acuity (VA). We analyzed VA, intraocular pressure (IOP), foveal thickness (FT), total macular volume (TMV), and pattern changes that occurred between pre-operation and 1 month post-operation.

The duration of DM was short in Type 3 DME patients. There were no differences in age or the duration of decreased VA. Pre-operative VA was higher in Type 1 than in Type 2 or 3 patients. FT and TMV increased in thickness from Type 1 through Type 3. VA after IVTA improved in Types 2 and 3. FT and TMV after IVTA decreased in each type. However, the extent of the changes in Types 2 and 3 was greater than that in Type 1. Seventy-four percent of Type 2 and 83% of Type 3 changed to Type 1 after IVTA.

This study found that there were differences in the therapeutic effect of IVTA among patients with different DME patterns. According to our results, the effectiveness of IVTA can be predicted, which we believe will help to objectively determine DME treatment.