Clinical Study Of Phakic Posterior Chamber Intraocular Lens Implantation For Treatment Of High Myopia

Objective: To evaluate efficacy and safety of phakic posterior chamber intraocular lensimplantation for high myopia and discuss the changes of central vault over the post-operativetime.Methods:40patients (80eyes) with high myopia who underwent phakic posteriorchamber intraocular lens implantation were recruited. Comprehensive examination includingrefraction, uncorrected visual acuity (UCVA), intraocular pressure (IOP), corneal endothelialcount and central vault were performed preoperative and postoperative1month,3months,6months and12months, respectively. Meanwhile the postoperative complications wereobserved.Results: The postoperative uncorrected visual acuity reached or exceeded preoperativebest corrected visual acuity in79eyes of80eyes. The postoperative uncorrected visual acuity25eyes0.8(approximately31.3%),55eyes1.0(approximately68.9%) while thepreoperative best corrected visual acuity43eyes0.8(approximately53.8%),37eyes1.0(approximately46.1%). The mean safety and efficacy indices were1.210.17and1.190.27, respectively. The mean preoperative spherical refraction was-10.724.31and themean spherical refraction were0.001.07,-0.161.26,-0.391.33,-0.170.79at1month,3months, the6months and the12months after operation, respectively. There was nostatistically significant difference in mean spherical refraction post-operative1month and12months.(t=1.23, p=0.22). The preoperative mean IOP was14.232.423mmHg andpostoperative IOP were13.682.98mmHg,13.602.52mmHg,13.602.72mmHg,13.552.39mmHg at1month,3months, the6months and the12months, respectively. There was no significant difference between preoperative and postoperative (t=1.718, p=0.09).Chronic uveitis and iris depigmentation didn’t occurre during follow-up. The preoperativecorneal endothelial density of ICL patients was2582.14±314.55cell/mm2,the postoperativecorneal endothelial density were2456.55±361.39cell/mm2、2427.93±369.41cell/mm2、2463.70±311.82cell/mm2、2766.56±348.33cell/mm2at1month,3months, the6months andthe12months, respectively.1year postoperative it decreased4.1%. During follow-up, therewas no case of cornea edema and other lesions. Central vault were416.93186.87m(99.0~937.0m),400.12194.75m (101.0~905.0m),383.81187.66m (74.0~809.0m),371.09181.42m (74.0~763.0m) after operation1month,3months, the6months and the12months, respectively. The vault changes were-16.8161.27m,-16.3146.41m,-15.1250.49m at1month to3months,3months to6months,6months to12months,respectively. And the vault decreased with statistical significance (z=-2.76, p=0.00；z=-3.75,p=0.00；z=-2.68, p=0.00), especially at3months to6months as well.Conclusion: Phakic posterior chamber intraocular lens implantation for high myopia ishigh efficacy and safety, and central vault has a small downward trend with over time.