Abstract
Purpose: :
The goal of this ex vivo study was to compare the measurements of empty capsular bag diameter of human cadaver eyes using a modified capsular tension ring system and surgical calipers, using the Miyake-Apple technique.
Methods: :
A total of 9 human cadaver eyes (age range: 48 to 75 years) were used in this study. White-to-white diameter, equatorial diameter and axial length were measured and anterior chamber depth was measured using ultrasound biomicroscopy (UBM). The globes were prepared for surgery using the Miyake-Apple technique and, after removal of the cornea and iris, the capsular bag diameter was measured in two meridians with surgical calipers before and after lens extraction. After the modified capsular tension ring was implanted, the capsular bag was measured in two meridians using calipers as well as the ring measurement system.
Results: :
The mean natural lens diameter of the human eye was 9.57 mm (range: 9.2 - 9.95 mm). The mean capsule bag diameter increased slightly after lens extraction to 9.75 mm (range 9.6 - 9.85). The mean capsular bag diameter measured with the modified capsular tension ring using the ring measurement system/viscoelastic was 10.32 mm (range: 10.0 mm to 10.65 mm). There was no difference in the measurements (no measurement variation greater than 0.1 mm) of the empty capsular bag with the ring with and without viscoelastic. The capsular bag diameters measured with ring measurement system/viscoelastic were slightly larger than the measurements with surgical calipers (mean 10.11 mm, range: 9.9 - 10.4 mm).
Conclusions: :
It is difficult to measure the diameter of the evacuated capsular bag in vivo. The modified capsular tension ring system may be used to measure the capsular bag diameter intra-operatively. In the peer-reviewed literature, it is well understood that the sizing of accommodating intraocular lenses (IOLs) is a critical parameter in optimal performance. The modified capsular tension ring system may aid in the understanding of IOL sizing and optimization of accommodative amplitude.
Keywords: accommodation • cataract • imaging/image analysis: non-clinical