CLINICAL SIGNS OF THE PIGMENT DISPERSION SYNDROME IN BLACKS

Background. The pigment dispersion syndrome (PDS) is considered rave i n blacks, and minimal literature exists concerning the condition in th is patient population. The diagnosis of PDS in blacks may present uniq ue challenges because some of the typical clinical signs that are pres ent in whites, including iris transillumination defects, posterior iri s bowing, and noticeable anterior iris stromal pigment dusting, may no t occur as commonly. Diagnosis can be particularly difficult when neit her these signs nor significant corneal endothelial pigmentation exist s. Although zonular and peripheral lens pigment has been found to be c onsistently present in whites with PDS, attention has not been given t o this as a potentially important diagnostic sign in blacks. Methods. From among a primary care population, we identified and studied 7 pati ents (13 eyes) who exhibited moderate to heavy trabecular meshwork (TM ) pigmentation, as well as zonule and/or peripheral lens pigmentation. Patients were identified during routine clinical care provided by one of the authors, as well as from notification by other practitioners. Ail patients received complete eye examination and other signs of PDS were looked for. Results. Four males and 3 females were identified, th eir average age being 37 years (range = 15 to 51) at the time of their initial identification. All but one patient was myopic (average appro ximate to -2.50 D spherical equivalent). Iris transillumination defect s were present in only one eye of one patient, and no eyes showed over t posterior iris bowing, although the iris contours were usually flat and the anterior chambers appeared relatively deep. Corneal endothelia l pigmentation was frequently barely detectable and could not be relie d on as a predictor of trabecular meshwork or lenticular pigmentation. Glaucoma, or a suspicion of glaucoma due to increased intraocular pre ssure (IOP) or cupping, was common among the group. Using heavy TM pig mentation as well as any degree of zonular and/or peripheral lenticula r pigmentation as a criteria for the diagnosis of PDS, we calculated t he prevalence of PDS among blacks in a nonreferred primary care popula tion (> age 7) to be at least 15 cases per 10,000. Conclusions. More i nvestigation is needed to study the clinical presentation of PDS in bl acks because it may be substantially different than in whites. Zonular and peripheral lenticular pigmentation may be a particularly useful d iagnostic sign of PDS in blacks, especially in those cases where other traditional signs, including iris transillumination defects, pronounc ed corneal endothelial pigmentation, posterior iris bowing, and visibl e anterior iris stromal pigment dusting, are absent. The ''classic'' v ariety of PDS may be more common among blacks than previously recogniz ed.