Non invasive evaluation of pigment dispersion syndrome using dynamic light scattering.

Purpose: The goal of this pilot study is to evaluate patients affected by pigment dispersion syndrome (PDS) using the technique of dynamic light scattering (DLS) in the aqueous humor (AH). Methods: Dynamic light scattering is a technique able to detect abnormalities at molecular level in ocular tissues. DLS particle size measurements are performed in the AH. 16 patients affected with PDS (16 eyes; mean age: 53.3{+/-}14.1; gender: 8 male, 8 female) and 15 normal subjects (15 eyes; mean age: 64.1{+/-}15.2; gender: 3 male, 12 female) were evaluated for the study. Results: The measuring range of diameter is between 50 and 2000 nm. The mean diameter of particles in PDS eyes was found to be 761{+/-}638 nm, whilst in normal eyes was 135{+/-}193 nm (t-Student test: P=0.009). DLS measurements showed a significantly higher prevalence of particles with a mean diameter under 500nm in normal eyes when compared with PDS eyes (93.3% normal eyes vs 47% in PDS eyes; Fisher's exact test: P=0.013). Conclusions: Larger size particles were detected in PDS eyes compared with normal cohorts. DLS can be used to detect pigment dispersion syndrome non invasively.