Purpose:To report on five cases of unusual bilateral stromal depigmentation of the iris and pigment dispersion masquerading as uveitis.Methods:We describe the clinical features of five consecutive patients who presented with acute depigmentation of the iris stroma between June and October 2003.Results:Four patients were female,one was male.Age at presentation ranged from 15 to 25 years.Presenting symptoms were sudden-onset ocular discomfort and red eye in four patients and change of eye color in one patient.All patients had bilateral involvement,with a symmetrical diffuse depigmentation of the iris stroma in three cases and patchy areas of iris depigmentation in two.Other common features were mild ciliary injection(seven eyes) ,Krukenberg spindle(seven eyes) ,circulating pigment in the anterior chamber(eight eyes) ,and heavy pigment deposition in the angle(ten eyes) .No eyes had iris transillumination defects,inflammatory keratic precipitates or inflammatory cells in the anterior chamber.Systemic laboratory work-up was unrewarding in all cases,and PCR analysis of the aqueous humor for HSV1 and 2 was negative in one patient.Four patients were treated with a short course of topical corticosteroids and three with oral acyclovir.One patient was lost to follow-up.The remaining four patients were followed up for 6-19 months with a stable clinical picture.Conclusion:In contrast to pigment dispersion syndrome,pigment seemed to be released from iris stroma in the five cases described here.Although patchy depigmentation of the iris resembled the lesions seen in herpetic iridocyclitis in two of the patients,symmetrical bilateral involvement and lack of intraocular inflammationwere the differentiating features.The patients described here could represent a new entity or an unusual presentation of herpetic eye disease. Purpose: To report on five cases of unusual bilateral stromal depigmentation of the iris and pigment dispersion masquerading as uveitis. Methods: We describe the clinical features of five consecutive patients who presented with acute depigmentation of the iris stroma between June and October 2003. Results: Four patients were female, one was male. Age at presentation ranged from 15 to 25 years. Presenching symptoms were sudden-onset ocular discomfort and red eye in four patients and change of eye color in one patient. All patients had bilateral involvement, with a symmetrical diffuse depigmentation of the iris stroma in three cases and patchy areas of iris depigmentation in two. Other common features were mild ciliary injection (seven eyes), Krukenberg spindle (seven eyes), circulating pigment in the anterior chamber (eight eyes), and Heavy pigment deposition in the angle (ten eyes) .No eyes had iris transillumination defects, inflammatory keratic precipitates or inflammatory cells in the anterior chamb er.Systemic laboratory work-up was unrewarding in all cases, and PCR analysis of the aqueous humor for HSV1 and 2 was negative in one patient. Patients were treated with a short course of topical corticosteroids and three with oral acyclovir. One patient was lost to follow-up.The remaining four patients were followed up for 6-19 months with a stable clinical picture. Conlusion: In contrast to pigment dispersion syndrome, pigment seemed to be released from iris stroma in the five cases described here. Though patchy depigmentation of the iris resembled the lesions seen in herpetic iridocyclitis in two of the patients, symmetrical bilateral involvement and lack of intraocular inflammationwere the differentiating features. the disease described in could could a new entity or an unusual presentation of herpetic eye disease.