Age-stratified normative lens densitometry in children: zone-specific reference curves from 4-18 years.

CLINICAL RELEVANCE: Quantitative evaluation of lens transparency may aid the clinical assessment of normal and abnormal lenticular changes during childhood. BACKGROUND: Scheimpflug imaging enables objective measurement of crystalline lens light backscatter. While age-related increases in lens densitometry are well documented in adults, normative paediatric data remain limited. Because lens development in childhood differs fundamentally from adult cataractogenesis, age-stratified reference standards are required. METHODS: This cross-sectional study included 188 eyes from 188 participants aged 4-18 years. Scheimpflug imaging (Pentacam HR) was used to measure global and zone-specific lens densitometry (nucleus 0-2 mm, anterior cortex, posterior cortex, annulus 2-4 mm, annulus 4-6 mm). Demographic and biometric parameters, including visual acuity, refraction, keratometry, anterior chamber depth, lens thickness, and pupil diameter, were recorded. RESULTS: The mean age was 12.5 ± 3.6 years (range 4-18), with 53.2% male. Mean global lens density declined from 7.98 ± 0.41 in children aged 4-9 years, to 7.93 ± 0.21 in those aged 10-13 years, and further to 7.72 ± 0.50 in adolescents aged 14-18 years (p < 0.001). Nuclear density showed the steepest decrease, from 8.53 ± 0.57 to 8.23 ± 0.28 and then 7.89 ± 0.29 across the three age groups (p < 0.001). Anterior cortical density increased slightly (7.25 ± 0.77 → 7.20 ± 0.58 → 7.53 ± 0.73, p = 0.028), while posterior cortical density rose modestly (4.63 ± 0.76 → 4.46 ± 0.69 → 4.83 ± 0.65, p = 0.005). Annulus 2-4 mm and 4-6 mm values progressively decreased from childhood to adolescence (p < 0.001 for both). CONCLUSIONS: Lens density decreases across childhood, most markedly in the nucleus, reflecting physiologic maturation.