Prognostic factors for visual acuity improvement after intravitreal triamcinolone injection

In some patients with macular oedema, intravitreal triamcinolone acetonide injection (IVTA) fails to improve visual acuity, although oedema shows clinical and angiographic improvement. Side effects can include increased intraocular pressure, cataract development, and (rarely) endophthalmitis. Our purpose was to identify prognostic factors for visual acuity improvement after IVTA.

Data on patients treated by IVTA for macular oedema were retrospectively reviewed. Three months postinjection, visual acuity was rated as 'improved' (two or more Snellen lines gained) or 'nonimproved' (unchanged or worsened). Comparative demographic data and pre- and post-IVTA clinical and fluorescein angiographic findings were analysed with SPSS software.

Of 57 eyes (57 patients), 27 (47%) improved after IVTA. Initial visual acuity ('good', 'moderate', or 'poor') and aetiology of macular oedema (diabetic, venous occlusion, or pseudophakic) did not differ between the two groups. Improvement occurred in significantly more eyes with clinical or angiographic evidence of cystoid macular oedema (CME) than in those with diffuse retinal thickening (P=0.04) or diffuse leakage on fluorescein angiography (P=0.02), respectively, and in significantly more pseudophakic than phakic eyes (P=0.046).

Pseudophakia and clinical or angiographic CME, but not aetiology or initial visual acuity, were prognostic of visual acuity improvement after IVTA for macular oedema.