Full shape crystalline lens geometrical changes with age from 3-D OCT images in vivo and ex vivo

Abstract

Purpose : Quantifying the geometrical changes of the human crystalline lens with age is essential for the design of solutions for age-related disorders such as cataract and presbyopia. We estimated the full shape geometry of the crystalline lens ex vivo and in vivo using optical coherence tomography (OCT)

Methods : 3-D OCT images were acquired from isolated crystalline lenses obtained from human donor eyes (RIEB, Hyderabad, India, n=17; TFS Bank, Barcelona, Spain, n=33) ex vivo and subjects in vivo in a maximally accommodated state (IO-CSIC, Madrid, Spain, n=58), using two custom-developed spectral domain OCT systems, provided with distortion correction routines. Ages ranged from 5-71 years & 21-87 years in the ex vivo and in vivo samples, respectively. Lens volume (VOL), surface area (LSA), thickness (LT), diameter (DIA), and equatorial plane position (EPP) were calculated using custom-developed automatic algorithms, both ex vivo and in vivo using a new methodology that extrapolates realistically the information visible through the pupil (Martinez-Enriquez et al. IOVS 2016). In vivo and ex vivo estimates were analysed as a function of age, and linear regression models were compared

Results : In the ex vivo lenses, VOL and LSA increased linearly with age at rates of 1.19 mm³/year (r=0.85, p<0.01) and 0.69 mm²/year (r=0.75, p<0.01) respectively. LT and EPP showed a biphasic trend, decreasing rapidly in the first 20 years (m=-0.039 mm/year, r=-0.78, p<0.01 for LT; m=-0.028mm/year, r=-0.81, p<0.01 for EPP) and increasing slowly afterwards (m=0.018 mm/year, r=0.82, p<0.01 for LT, m=0.006 mm/year, r=0.49, p<0.01 for EPP). DIA increased rapidly up to 15 years (m=0.23 mm/year, r=0.92, p=0.01) and slowly afterwards (m=0.01 mm/year, r=0.43, p<0.01). The mean absolute difference between ex vivo and in vivo linear regressions within the same age range (21-71 y.o) was below 12 mm³ for VOL, 17 mm² for LSA, 0.3 mm for DIA and 0.07 mm for EPP. The slopes’ differences were 0.01 mm³/year, 0.08 mm²/year, 0.002 mm/year for VOL, LSA and DIA respectively

Conclusions : 3-D OCT measurements with dedicated algorithms allow ex vivo and in vivo quantification of the full shape of the crystalline lens. The similarity of the lens dimensions and age-related trends measured in vivo and ex vivo reflect the validity of the methodology. All the analyzed parameters ex vivo changed significantly with age, with a biphasic trend for LT and EPP

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.