I would like to thank Dr Brown for her comments regarding the case series we published dealing with pediatric Horner syndrome and the use of apraclonidine. Her reasoning behind the need for a simple office test to evaluate anisocoria in children was exactly correct.
We are aware of the article that Dr Brown published last year regarding the use of 0.5% apraclonidine instead of the 1% formulation.1 We did not comment on her article in our study because it was published after ours had already been submitted for publication. Certainly 0.5% apraclonidine would be a more attractive agent than the 1% formulation as a diagnostic tool (if equally efficacious) because it is more readily available and would have less potential side effects. Hopefully, future studies enrolling larger groups of patients will determine the sensitivity and specificity of these agents in the diagnosis of Horner syndrome.
Bacal D. The Utility of 0.5% Apraclonidine in the Diagnosis of Horner Syndrome—Reply. Arch Ophthalmol. 2005;123(4):578. doi:10.1001/archopht.123.4.578-b