Spontaneous absorption of congenital cataract in trisomy 21.

We report a case of spontaneous cataract absorption over a period of 19 weeks in a 5-week-old boy with trisomy 21. Ultrasound biomicroscopy images at 5 and 24 weeks of age showed that 71% of the initial lens thickness was absorbed during this period. At surgery, the lens thickness was 0.92 mm in the right eye and 0.91 mm in the left eye. Uncomplicated cataract extraction was performed. Trypan blue staining revealed an area of possible lens leakage through the anterior lens capsule in the left eye, suggesting a mechanism for cataract absorption.