The second sign is the formation of a vertical line of deposited pigment on the central corneal endothelium, known as a Krukenberg spindle; this is due to the pigment being distributed around the anterior chamber by convection of the aqueous.
Table 1 Clinical features and patient characteristics of those affected by PDS and PXS Pigment dispersion syndrome Pseudoexfoliation syndrome Iris transillumination defects Pupillary margin changes Krukenberg spindle Anterior lens material Brown band of pigment on Grey material on Schwalbe's line trabecular meshwork Patient in their 30s and 40s Patient in their 60s and 70s Men more than women Women more than men Myopia Emmetropia or hyperopia
With regard to PDS, a significant asymmetry was noted with prominent features in the right eye including dense
Krukenberg spindle, iris transillumination defects, heavily pigmented trabecula, wide open angle, and Zentmayer ring (Figure 1).
Pigment dispersion syndrome (PDS) results from posterior bowing of the iris and rubbing between the lens zonules and epithelial layer of the iris, and usually affects myopic eyes in men during the third to fourth decade of life.[sup][1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11] The literature indicated that Caucasians have the highest prevalence of PDS among all races,[sup][12] with clinical characteristics including Krukenberg spindle, homogeneous trabecular meshwork (TM) pigmentation, and spoke-like mid-peripheral iris transillumination defects (ITDs), which are referred as a triad of PDS.
Diagnostic criteria for PDS in Chinese patients included at least two of the following three signs: Krukenberg spindle, homogenous moderate to heavy TM pigmentation (≥ Scheie II), and any degree of zonular and/or lenticular pigment granule dusting.
