Implantation Of Angle-supported Phakic Anterior Chamber Intraocular Lens For The Correction Of Severe Myopia

Objective:To evaluate the effectiveness, predictability, and safety of the implantation of angle-supported Phakic anterior chamber intraocular lens(PAC-IOL) for the correction of severe myopia.Method:In this prospective study, 15 eyes with myopia were implanted with Phakic 6H2 PAC-IOL in Fujian Medical University Union Hospital. Visual acuity, refraction, intraocular pressure, corneal endothelium, accurate measurement of biological parameters, the situation of corneal,pupil,PAC-IOL,fundus were observed.Result :All of 15 eyes were implanted successfully and have been followed-up for 3a. The mean uncorrected visual acuity (UCVA) was 0.06±0.03 pre-operatively and 0.58±0.26 post-operatively. There were significant difference between pre-and 3a post-operative mean uncorrected visual acuity(UCVA)(t=--7.602,P<0.01).The mean best corrected visual acuity(BCVA) was 0.54±0.18 pre-operatively and 0.74±0.26 post-operatively. There were significant difference between pre-and 3a post-operative mean corrected visual acuity(Z=-2.214,P<0.05). The mean preoperative spherical equivalent (SE)degree (-16.75±3.66) D, postoperative residual refraction was (-1.75 ~ 1.25) D, mean spherical equivalent degree(SE) (-0.38±0.87) D, there were significant difference between pre-and 3a post-operative mean spherical equivalent(SE) degree (t =- 16.840, P <0.01) . The mean corneal endothelial cell count (2934±455) a / mm2 pre-operatively and (2485±812) a / mm2 post-operatively, there were not significant difference between pre-and 3a post-operative mean corneal endothelial cell count (t = 1.869, P> 0.05) ,the average decline of 15.3 %.1 (6.7%) postoperative glare and intraocular lens optical pupil diameter greater than the ministry, the crystal has week of climbing into the incision iris, lens optical center slightly offset; 1 (6.7%) crystal around the surface of banded iris pigment dispersion, its a week of climbing into the incision iris, lens optical center slightly offset; 1 (6.7%), oval-shaped pupil deformation, and 2 eyes (13.3%) slightly offset lens optical center. However, no significant effect on vision. The safety index (SI) of operation was 1.37, the efficacy index (EI)of that 1.08,the predictability index(PI) of operation was -0.023. All patients expressed satisfaction with the postoperative visual acuity.Conclusion : This group of angle-supported Phakic anterior chamber intraocular lens(PAC-IOL) treatment of high myopia patients showed higher satisfaction with postoperative visual acuity , improved significantly quality of life .The operation which predictive index was -0.023 ,the efficacy index 1.08 and the safety index 1.37 had few complications, but corneal endothelial count a certain loss and corneal endothelial decompensation did not occur, long-term endothelial situation needs further study. The simple operation is one of the methods available of correction of high myopia with good predictability, exact efficacy and safety .