Ultrasound biomicroscopic measurement of development of anterior chamber angle.

AIM To establish normative values for the anterior segment in normal infants and children in relation to age. METHODS Anterior segments were measured in 46 normal infants and children (21 males and 25 females, aged from 1 to 60 months (mean 17.09 (SD 16.99) months)), by use of ultrasound biomicroscopy. RESULTS Anterior chamber depth, trabecular-iris angle, angle opening (trabecular-iris) distances at 250 and 500 microm from the scleral spur, and the thickness of the thickest part of the iris were 1724-3473 microm (2505 (SD 480) microm), 15.35-44.79 degrees (28.74 (7.46) degrees ), 116-367 microm (247.4 (65.9) microm), 166-509 microm (349.5 (87.1) microm), and 249-579 microm (434.6 (74.6) microm), respectively. All factors in this study showed a significant correlation with logarithm of age (r = 0.937, p = 0. 0001; r = 0.867, p = 0.0001; r = 0.929, p = 0.0001; r = 0.917, p = 0. 0001; r = 0.748, p = 0.0001), and significantly correlated with each other. CONCLUSIONS Ultrasound biomicroscopy is a powerful tool for obtaining precise images and measurement of the development of the anterior segment in infants and children. Normative values were established for anterior segment dimensions in relation to age. Anterior chamber depth, trabecular-iris angle, angle opening distances at 250 and 500 microm from the scleral spur, and iris thickness showed linear increases in relation to logarithm of age.