Abstract
Purpose :
To evaluate the tilt of the crystalline lens (lens) or intraocular lens (IOL) using a prototype of a full-length OCT based biometer.
Methods :
One hundred eighty-two cases of right eye in 182 Japanese patients with cataract were enrolled in this study. Mean patient age was 67.9 ± 15.1 years.
Before and after cataract surgery, the distribution of tilt magnitude and orientation of the lens or IOL were investigated using a prototype of IOLMaster700 (Carl Zeiss Meditec AG, Germany).Tilt orientation axis and tilt magnitude were derived from fitting a plane to 3D points sampled from 18 parabolas that were fitted to lens surfaces of 18 B-scans for each eye. Tilt magnitude and orientation was expressed by the normal vector of the plane and additionally as a pair of angles in spherical coordinates. We investigated the correlation between the tilt magnitude of lens or IOL and the axial length. As a subgroup analysis, we investigated 14 eyes to find the correlation between pre- and postoperative values for tilt magnitude and orientation.
Statistical analysis was performed using the paired t test, Spearman’s correlation coefficient and significant probability. Data were analyzed using SPSS software (ver.21, SPSS Inc.). A p value less than 0.05 was considered statistically significant.
Results :
Mean orientation and tilt magnitude in phakic eyes were 15.76°±25.59° and 3.30°±0.97°, respectively. Mean orientation axis and tilt magnitude in pseudophakic eyes were 19.29°±33.08° and 4.66°±1.79°, respectively. There was a significant negative correlation between the tilt magnitude and the axial length in both phakic and pseudophakic eyes (phakia; R = −0.18, p = 0.016, pseudophakia; R = −0.33, p = 0.006).
In the subgroup analyses, there was a significant correlation between tilt magnitudes before and after cataract surgery (R = 0.566, p = 0.035). Postoperative mean tilt magnitude was larger than preoperative (p < 0.0001).
Conclusions :
Using a full-length OCT-based biometer, we could measure the tilt magnitude and orientation in both lens and IOL. The current study revealed that the tilt magnitude of the lens or IOL negatively correlated with axial length. Since the tilt-magnitudes before and after IOL implantation showed significant correlation, characteristics of the lens before surgery could be maintained after IOL implantation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.