Stability Of Intraocular Lens And Refractive Shift After Simultaneous Vitrectomy And Cataract Surgery

Objective1. To compare the decentration and tilt of three different kind of intraocular lens after combined surgery (phacoemulsification and intraocular lens implantation combined with vitrectomy).2. To investigate the refractive shift after combined surgery(phacoemulsification and intraocular lens implantation combined with vitrectomy)by comparing the difference between the predictive and postoperative refractive power.Methods1. Combined surgery were performed on 58 eyes, including three kinds of intraocular lens[4-loop hydrophilic acrylic intraocular lens(groupl),2-loop hydrophilic acrylic intraocular Iens(group2) and 2-loop hydrophobic acrylic intraocular lens(group3)]. To measure the decentration and tilt with Scheimpflug imaging system after 6 months.2. Combined surgery (combined group) were performed on 48 eyes, and simple cataract surgery (cataract group) on 50 eyes. Combined group were divided into 2 groups:balanced salt solution group and gas group. The refractive condition and the axial length preoperative and six months postoperative were compared. The spread between predictive spherical equivalent (PSE) and actual spherical equivalent (ASE) were compared between combined group and cataract group,balanced salt solution group and gas group.Results1. The mean decentration in group1, group2 and group3 were (0.13±0.07)mm, (0.15±0.08)mm and (0.16±0.11)mm respectively, which showed no statistical differences(P=0.668); The mean tilt in group1, group2 and group3 were (2.29±1.49)°,(4.00±1.25)°and (4.36±1.78)°respectively, which showed statistical differences(p=0.03); The tilt of group1 was less than two other group and showed statistically significant differences(P=0.011, P=0.001).2. In combined group, the mean PSE was (-0.1±0.42)D and ASE was (-1.0±1.1)D, and the difference was significant (t=6.687,P<0.05).Patients underwent combined surgery showed a statistically significant myopic shift compared with those receiving underwent simple cataract surgery(t=-3.792,P<0.05),the refractive shift of balanced salt solution group gas group were (-0.76±0.89) and (-1.19±0.94)D respectively, and there was no significant difference(t=-1.530,p>0.05).Conclutions1. Three different types of intraocular lens are all stability after combined surgery, tilt in 4-loop intraocular lens is less than 2-loop intraocular lens.2. Actual refractive errors in the combined surgery group is found to shift to myopia.