Higher dose of intravitreal triamcinolone had greater effect on macular edema

A higher dose of intravitreal triamcinolone had a longer treatment effect and a stronger effect on visual acuity improvement than two lower doses, according to a study.

U.H.M. Spandau, MD, and colleagues in Germany conducted a prospective, randomized, double-masked study to evaluate the effect of different doses of intravitreal triamcinolone acetonide in patients with diffuse macular edema.

They studied 27 eyes of 27 patients with diffuse macular edema, with eight eyes receiving 2 mg of intravitreal triamcinolone, 10 patients receiving 5 mg and nine patients receiving 13 mg. Follow up ranged from 3 to 12 months.

Greater increase in visual acuity was significantly correlated to the dosage of triamcinolone (P = .046). Patients in the 2 mg and 5 mg groups did not show a significant difference in VA from baseline to final follow-up. In the 13 mg group, VA increased from 0.15 at baseline to 0.24 at the final follow-up. The number of eyes showing an increase in best VA by two or more Snellen lines was higher, but not significantly, in the 13 mg group (seven eyes) than in the 5 mg group (six eyes) and the 2 mg group (three eyes).

The duration of the effect of the injection increased significantly with the dosage amount (P = .014). Increase in IOP was not significantly associated with the injection, the researchers said.

The researchers noted that the limitations of their study included “the possible inaccuracy of the final dosage of triamcinolone acetonide after the filtration process before the injection.” The filtration process and actual injection dose “may be a weakness of many studies using filtered triamcinolone for intravitreal injection.” A secondary limiting factor of the study may have been the relatively small number of patients, they said.

The study is published in the August issue of the British Journal of Ophthalmology.