Abstract
Purpose:
To propose a method for three-dimensional (3-D) quantification of relationship between the Intraocular lens (IOL) and capsule with anterior segment sweep-source optical coherence tomography (AS-SS-OCT)
Methods:
The OCT images were acquired by a commercial available AS-SS-OCT (Casino SS-1000; Tomey, Nagoya, Japan) using a light source with central wavelength of 1310nm.. Custom software was developed to process the image and yield the biometry of in situ IOL and dimensions of the capsule. The anterior and posterior boundary of cornea and IOL were segmented using dynamic programming based on graph theory. A registration algorithm based on the shape of anterior cornea was applied to reduce the effects of eye motion. The size and dencentration of continuous curvilinear capsulorrhexis (CCC), IOL tilt and dencentration, anterior chamber depth (ACD), central pupil-cornea distance (PCD), central lens-pupil distance(LPD), posterior capsule volume(PCV) were obtained after optical distortion correction by three-dimensional ray trace. Five eyes of 5 age-related cataract patients were enrolled to demonstrate the feasibility of anterior segment biometry at 1 day after surgery. 10 sets of 3-D OCT data from 2 patients at 1 day, 1 week, 2 weeks, 1 month, 3 months postoperatively were included for showing the changes of IOLs position and capsule dimension with time.
Results:
The proposed method successfully reconstructed 3-D anterior segment of the eyes with IOL and obtained the 3-D dimensional parameters. There was no significant changed between two repeated measurements for any of the measured parameters (t-test, P>0.05). The size of CCC was 5.00±0.20mm and PCV was 0.65±0.47mm3 at 1 day after surgery. The dencentration and tilt of IOLs were 0.13±0.11mm and 0.97±0.63 deg, respectively. ACD was significantly correlated with LPD (r=0.932; P<0.05) while there was no significant correlation between ACD and PCD (r=0.683; P>0.05) during the 3 months after surgery. The movement of IOL was correlated with the movement of the center of CCC(r=0.958; P<0.05) during the 3 months after surgery.
Conclusions:
It demonstrated that the three-dimensional reconstruction method with AS-SS-OCT has the potential to quantify the biometry of IOL and capsule within the eye. The ACD decreased with forward movement of IOL and the position of IOL moved with the position of CCC during the 3 months after surgery.
Keywords: 567 intraocular lens •
550 imaging/image analysis: clinical •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)