Flag iris syndrome

Insufficient pupillary dilation with normal mydriatic drugs can be caused by pathological or paraphysiological precedents in the iris; the most frequent are the presence of posterior synechiae (due to previous uveitic facts or previous surgery or prolonged use of myotics) and atrophy and sclerosis of the iris stroma and pupillary sphincter (capsular pseudoexfoliation syndrome or due to tissue senescence facts alone).

A new association between poor mydriasis and the use of tamsulosin (Pradifâ, Omnicâ), an a-1A receptor blocker, has recently been described (1). This drug is used to treat patients with prostatic hypertrophy, as it increases the flow of the lower urinary tract by relaxing the prostatic smooth muscle. The authors define as Intraoperative Floppy Iris Syndrome (IFIS) a triad of intraoperative signs: poor mydriasis, flag iris with tendency to prolapse in the corneal tunnel and progressive miosis. This work is composed of two studies: a retrospective series that evaluated 511 patients (706 eyes) looking for those on tamsulosin therapy and a prospective series, which evaluated 741 patients (900 eyes), looking at the frequency of IFIS. In the first series, 16 patients on tamsulosin therapy were identified, of whom 10 manifested IFIS (63%). It should be noted that of the entire series these were the only eyes to manifest this phenomenon (2%, 10/511). In the second series IFIS occurred in 16 patients (2.2%, 16/741), of these 15 were taking tamsulosin (the 16th patient was diabetic).