Brushfield spots and Wölfflin nodules unveiled in dark irides using near-infrared light

Abstract

Wölfflin nodules and Brushfield spots were described essentially in light colored irides. The purpose of our study is to determine if these iris features are also present in dark irides, hidden by melanin granules of the anterior leaf of the iris. We examined iris images, taken with standard visible white, as well as with near-infrared light of children with Down syndrome and without. Using white light, Brushfield spots were seen in 21% of children with Down syndrome, and Wölfflin nodules in 12% of controls (p < 0.001), all noted in those with lightly colored irides. Brushfield spots were detected in 67% of children with Down syndrome using near-infrared light compared to 21% using white light (p < 0.001). Wölfflin nodules were detected in 19% of controls using near-infrared light compared to 12% using white light. Peripheral iris thinning was present in 63% of children with Down syndrome but in only 23% of those without (p = 0.001). Contraction furrows were less frequent in children with Down syndrome (16%) compared to controls (74%)(p < 0.001). Near-infrared light unveils Brushfield spots and Wölfflin nodules in dark irides. Clearing this discrepancy should assist in the elucidation of their pathophysiologic origin. A high prevalence of peripheral iris thinning is also present in children with Down syndrome along with a heretofore unreported reduction in iris contraction furrows.