Bilateral Acute depigmentation of the iris is a recently discovered condition described in the literature in Turkish patients1,2. This condition affects mainly young females and is characterized by acute bilateral stromal depigmentation without other pathologic ocular findings. These patients usually maintain normal vision and do not develop significant glaucoma from pigment collecting in the anterior chamber angle. This condition can be mistaken for Fuch’s heterochromic iridocyclitis, pigment dispersion syndrome, pseudoexfoliation syndrome, viral iridocyclitis, Varicella Zoster Virus, Herpes Simplex Virus, and Cytomegalovirus. Fuch’s Heterochromic iridocyclitis is characterized by unilateral presentation in all but a few cases, and is characterized by white-stellate keratic precipitates in the and low grade anterior chamber inflammation5, which our patient did not have. Pigment dispersion syndrome as well as pseudoexfoliation are conditions characterized by loss of pigment from the posterior iris pigmented epithelium with transillumination defects and accumulation of pigment in the anterior chamber angle as well as along the zonules and anterior lens capsule6, all of which were absent in our patient as well. Herpetic iridocyclitis is almost always unilateral, and accompanied by eye pain, redness, photophobia, mild to severe anterior chamber inflammation, possible hyphema, keratic preciptates, posterior synechiae, decreased corneal sensation, iris atrophy, irregular pupil, transillumination defects, and elevated intraocular pressure7. Again our patient had a complete absence of these findings during her course.
Bilateral Acute Iris Transillumination (BAIT) is another recent entity described in the literature as a condition with acute onset of bilateral iris transillumination defects with loss of associated iris pigment epithelium after using fluoroquinolones and other antibiotics.8 In our case, our patient did not have transillumination defects and did not take antibiotics before onset of her depigmentation.
BADI is a condition that is characterized by stromal loss of pigmentation with a lack of transillumination. Review of the cases of BADI including ours, we noted one important clinical feature which is a maintenance of iris pigmentation within 1-2mm of the pupil margin. The majority of cases presented in the literature had this common clinical feature1-4. BADI is also easily mistaken for iridocyclitis but given the absence of uveitis symptoms and a different pattern of depigmentation, it is a condition which should be readily made clinically. The etiology for such a condition is not well known as only 38.5% of patients in the review by Tugal-Tutkin had a viral prodrome before developing the condition2. In our patient she denied any viral prodrome but she reported monthly injections of Sarapin® injections in her face for chronic migraine monthly for a total of 12 months. Sarapin® which is a toxin obtained from pitcher plants, has been extensively studied for its analgesic effects. It acts upon the C fibers of nerves and contains an unidentified toxin that potentiates action of ammonium ions10, resulting in decreased pain. This injection has never been reported to cause any complications. It is unknown the effect of Sarapin on iris pigmentation. The timing of the treatment to the change in iris color suggests a relationship though coincidence may be the ultimate explanation.
Reports have shown that patients with this condition can have spontaneous re-pigmentation as well, however this has not yet been noted in our patient who we have been following for several years.
Our case is significant as it is the first reported in the Western Hemisphere, as well as the first case amongst identical twins with the unaffected twin sister serving as a “control”. As awareness of this condition increases, an etiogenesis may be discovered as more cases are studied.