Abstract
Purpose :
To describe anterior segment anatomy and structural changes with eye growth in normal infants, children, and young adults using ultrasound biomicroscopy (UBM) in order to provide a baseline for future comparison to eyes with primary congenital and juvenile glaucoma.
Methods :
Anterior segment UBM imaging was performed on 15 normal eyes of 15 patients age 0 to 25 years. Each image was analyzed according to a prospective protocol with quantitative measurements of each structure using ImageJ software. 19 parameters in 6 images of 1 eye per patient were evaluated using independent t-test and ANOVA. Pediatric and adult age groups were defined as patients under age 18 years and patients age 18-25 years, respectively (M=11.227 years). Patients were 36% male, 64% female, 57% African American, 21% Hispanic, and 21% Caucasian.
Results :
Mean anterior chamber (AC) width, area, perimeter, and height were significantly smaller in the pediatric age group (p=0.0091, 0.0016, 0.0034, 0.0011, respectively). AC width increased by 50% in the first year and was relatively unchanged until adulthood. AC height increased by 10% in the first year and an additional 15% by 5 years but did not undergo significant change from age 5 to early adulthood. The adult age group had a central corneal thickness (CCT) of 567.2+/-30.3um and a statistically significant negative correlation with age (R=-.085, p<.05), consistent with previously established trends. Sulcus to sulcus distance and trabecular-ciliary process (CP) distance increased linearly (R2=0.2676, 0.4234, p<0.05, respectively), both reaching adult size in the mid-teenage years. The cornea-ciliary body (CB) angle reduced with age (R=-0.015, p<0.05) while the cornea-iris and CB-sulcus angles showed no significant difference with increasing age.
Conclusions :
This UBM study establishes quantitative ocular growth trends for normal pediatric anterior segment anatomy. Many structures show logarithmic growth trends with maximal growth rates in the first 0-6 or 0-12 months of life. A few structures demonstrated slow linear growth trends. Specific quantitative knowledge of normal pediatric structure size and orientation is limited. This study aids our understanding of anatomy in the growing eye. A comprehensive description of normal pediatric anterior segment anatomy and growth may help identify abnormal structure size and growth variants in eyes with anterior segment pathology.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.