Ultrasound elastography for evaluating stiffness of the human lens nucleus with aging: a feasibility study.

Aim: To investigate the significance of ultrasound elastography for evaluating stiffness of the human lens nucleus in volunteers with different ages.

Methods: A total of 90 volunteers (lens transparency, uncorrected visual acuity ≥0.5, intraocular pressure: 14-19 mm Hg) were divided into 3 groups according to age: Group A (30 people, median age: 82±3.5y, mean axial lengths 23.7±0.5 mm); Group B (30 people, median age: 46±2.1y, mean axial lengths 23.9±0.4 mm); and Group C (30 people, median age: 22±3.5y, mean axial lengths 24.0±0.4 mm). Lens nuclear stiffness was measured by Free-hand qualitative elastography by independent operators. Strain gray scale and color-coded elastography maps were recorded. In each case, three consecutive detections were performed and strain ratio was used for statistical analysis.

Results: Elastography analysis showed excellent diagnostic performance for lens sclerosis. Lens strain ratio was lowest (0.03±0.01)% in Group A and highest (2.03±0.43)% in Group C. Lens strain ratio was moderate (0.64±0.10)% in Group B. There were significant differences between these three groups (<0.05). The lens nucleus strain rate changes with age. With aging, the lens nucleus strain rate and resilience decrease, demonstrating harder texture.

Conclusion: The relationship between human lens stiffness and age is demonstrated by ultrasound elastography. Older age is associated with lower strain ratio and less resilience of the lens.