Evaluation Of Pupil Diameter After Posterior Chamber Phakic Intraocularlens Implantation

Purpose:To evaluate the changes of pupil size under scotopic and photic conditions after Implantable Collamer Lens (ICL) implantation in eyes with high myopia.Methods:14eyes of7patients were enrolled. Before and1month after standardized ICL implantation, they underwent complete ophthalmologic examinations. Scotopic and photic pupil diameters were measured using WASCA aberrometer. Anterior chamber depth, pupil diameter, the distance between the ICL and the crystalline lens and the distance between the ICL and the cornea were examined using ultrasound biomicroscopy (UBM). The relationships between the changes of pupil diameters and the factors including the amount of vaulting, age, and spherical equivalent corrected by ICL were evaluated respectively. Statistical data were analyzed using SPSS18.0software.The difference was considered as significant when P<0.05.Results:The mean scotopic pupil diameters measured by WASCA aberrometer were5.54±1.17mm (range from3.83to7.16mm) preoperatively and5.20±0.97mm (range from3.17to5.99mm)1month postoperatively. The mean photic pupil diameters measured by WASCA aberrometer were3.92±0.67mm (range from3.02to4.84mm) preoperatively and4.37±0.99mm (range from2.73to5.51mm)1month postoperatively.The mean difference between photic and scotopic pupil diameters were1.62±0.72mm (range from0.74to3.19mm) preoperatively and0.82±0.34mm (range from0.22to1.29mm)1month postoperatively.The difference between preoperative and postoperative pupil diameters under scotopic and photic conditions measured by WASCA aberrometer were statistically significant ((t=2.226,P<0.05for scotopic conditions and t=-3.083,P<0.01for photic conditions).Statistically significance was also found between the preoperative difference between photic and scotopic pupil diameters and the postoperative difference between photic and scotopic pupil diameters(t=3.461,P<0.01). The mean pupil diameters measured by UBM were3.43±0.79mm (range from2.15to4.63mm) preoperatively and3.66±1.03mm (range from1.66to4.69mm)1month postoperatively.The difference between preoperative and postoperative pupil diameters measured by UBM was not statistically significant (t=-1.881,P>0.05). The mean anterior chamber depths were3.05±0.22mm (range from2.78to3.43mm)preoperatively and3.03±0.22mm(range from2.77to3.48mm)1month postoperatively.The difference between preoperative and postoperative anterior chamber depths was not statistically significant (t=0.577,P>0.05). The mean lens vault was0.44±0.28mm(range from0.03mm to0.92mm) and the mean distance between the ICL and the cornea was2.32±0.22mm(range from1.79-2.60mm)1month postoperatively. The change of photic pupil diameters measured by WASCA aberrometer and the change of pupil diameters measured by UBM afer operation had significant correlation with the vaults(P<0.05).The change of scotopic pupil diameters and the change of the difference between photic and scotopic pupil diameters afer operation measured by WASCA aberrometer,had no significant correlation with the vaults(P>0.05).The change of photic pupil diameters measured by WASCA aberrometer afer operation had significant correlation with the ages(P<0.05).The change of scotopic pupil diameters and the change of the difference between photic and scotopic pupil diameters afer operation,which were measured by WASCA aberrometer,and the change of pupil diameters measured by UBM,had no significant correlation with the ages(P>0.05).The change of scotopic pupil diameters and the change of the difference between photic and scotopic pupil diameters afer operation measured by WASCA aberrometer,had significant correlation with the spherical equivalent corrected by ICL (P<0.01).The change of photic pupil diameters measured by WASCA aberrometer and the change of pupil diameters measured by UBM afer operation had no significant correlation with the spherical equivalent corrected by ICL (P>0.05).Conclusions:The scotopic pupil diameter was decreased,the photic pupil diameter was increased and the difference between photic and scotopic pupil diameters was decreased after ICL implantation.That indicated the ICL implantation may limit the movement of pupil to some extent. The changes of pupil diameters after ICL implantation seem to be associated with the vault,age and the spherical equivalent corrected by ICL...