A quantitative study of the effect of ICL orientation selection on post-operative vault and model-assisted vault prediction.

Background: Appropriate vault height of implantable collamer lens (ICL) implantation matters for it has risks of corneal endothelial cell loss, cataract formation and intraocular pressure elevation, which could lead to irreversible damage to optic nerve. Therefore, pre-operative prediction for an ideal vault height is a hotspot. However, few data exist regarding quantitative effect of ICL orientation on vault height. This study is aimed to quantitatively investigate the effect of ICL implantation orientation on vault height, and built a machine-learning (ML)-based vault prediction model taking implantation orientation into account. Methods: 473 consecutive case series treated with ICL implantation were retrospectively analyzed (408 were horizontally implanted, and 65 were vertically implanted). Multivariable logistic regression analysis was performed to determine the association between ICL orientation and achieved vault. ML was performed to develop a new vault height prediction model taking ICL orientation into account. Receiver operating characteristic curve (ROC) and net reclassification index (NRI) were obtained to assess the prediction ability. Results: 95% of all the patients achieved 20/20 uncorrected distance visual acuity (UDVA) or better. No complications including cataract formation, dispersion or optic nerve injury were observed in any cases. Sex, sphere power, cylinder power, axis, ICL size and ICL orientation were all significant risk factors associated to vault height, and age was positively co-related. Of note, ICL size and ICL orientation were the top-ranking risk factors. Comparing to conventional horizontal implantation, vertical implantation could reduce the achieved vault by 81.187 µm (p < 0.001). In regarding to different ICL sizes, vertical implantation had no good to vault reduction when using ICL of 12.1 mm. However, it could reduce the vault by 59.351 µm and 160.992 µm respectively when ICL of 12.6mm and 13.2 mm were implanted (p = 0.0097 and p = 0.0124). For prediction of vault height, ML based model significantly outperformed traditional multivariable regression model. Conclusion: We provide quantitative evidence that vertical implantation of ICL could effectively reduce the achieved vault height, especially when large size ICL was implanted, comparing to traditional horizontal implantation. ML is extremely applicable in development of vault prediction model.

Short-term visual quality observation of femtosecond laser small incision lenticule extraction and evolution implantable collamer lens implantation in the correction of moderate myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the short-term visual quality outcomes after femtosecond laser small incision lenticule extraction(SMILE)and evolution implantable collamer lens(EVO-ICL)implantation for the correction of moderate myopia.METHODS: Prospective control study. A total of 51 cases(51 eyes)with moderate myopia who underwent SMILE or EVO-ICL implantation surgery at Weifang Eye Hospital from April 2021 to February 2022 were selected. They were divided into SMILE group(30 patients, 30 eyes)and EVO-ICL group(21 patients, 21 eyes)according to the surgical methods. The changes of visual acuity [uncorrected distance visual acuity(UDVA), corrected distance visual acuity(CDVA)], diopter [spherical equivalent(SE)] and related parameters of optical quality analysis system(OQAS Ⅱ)were observed before surgery and at 1wk, 1 and 3mo after surgery, and the quality of vision(QoV)questionnaire was completed.RESULTS: At 3mo after surgery, the safety index(postoperative CDVA/preoperative CDVA)of SMILE gruop and EVO-ICL group were 1.20(1.00, 1.20)and 1.20(1.00, 1.38), respectively, the efficacy index(postoperative UDVA/preoperative CDVA)were 1.00(1.00, 1.20)and 1.00(1.00, 1.20), respectively, and the percentage of SE within ±0.50D was 87% and 100%, respectively. In SMILE group, the objective scattering index(OSI)was increased after surgery, while modulation transfer function cutoff frequency(MTF cutoff), contrast visual acuity(VA)100%, and VA20% at 1wk and 1mo after surgery, and Strehl ratio(SR)and VA9% at each time point after surgery were all decreased compared with those before surgery(all P&#x0026;#x003C;0.05). The OSI, MTF cutoff, SR and VA of EVO-ICL group showed no difference at each time point after surgery compared with those before surgery(all P&#x0026;#x003E;0.05). The most common visual symptoms after SMILE and EVO-ICL implantation were visual haze and halos, respectively.CONCLUSION: Both SMILE and EVO-ICL implantation have good safety, efficacy and predictability in the short term after the correction of moderate myopia. Both groups had visual symptoms after surgery, but the overall satisfaction of patients was high. Furthermore, EVO-ICL implantation has better objective visual quality performance.

Validation of the vault prediction model based on the sulcus-to-sulcus diameter and lens thickness: a 925-eye prospective study.

BACKGROUND: To verify the accuracy and stability of the prediction formula based on the ciliary sulcus diameter and lens thickness and to analyse factors influencing the prediction results. METHODS: In total, 925 eyes from 506 subjects were enrolled in this prospective study between July 1, 2020, and June 30, 2021. Subjects were divided into four seasons, each spanning three months. The target vault was set to be between 300 µm and 700 µm according the prediction formula. The actual vault was measured one month postoperatively. The Bland-Altman test, 95% confidence intervals (95% CI) and 95% limits of agreement (95% LoA) were used to evaluate the agreement between the predicted vault and the actual vault. Eyes with absolute prediction errors greater than 300 µm were further analysed. RESULTS: The mean predicted vaults for the four seasons were 503 ± 99, 494 ± 96, 481 ± 92 and 502 ± 93 µm, while the mean actual vaults were 531 ± 189, 491 ± 179, 464 ± 179 and 529 ± 162 µm, respectively. The predicted and actual vaults of the overall subjects were 493 ± 95 and 500 ± 180 µm, respectively. Of the 925 eyes, 861 eyes (93.08%), 42 eyes (4.54%), and 22 eyes (2.38%) showed a normal vault, high vault, and low vault, respectively. Bland-Altman plots showed that the mean difference between the actual vault and predicted vault overall (± 95% LoA) was 6.43 ± 176.2 µm (-339 to 352 µm). Three UBM features may lead to large prediction errors (more than 300 µm): wide iris-ciliary angle (ICA), iris concavity and anteriorly positioned ciliary body. CONCLUSIONS: This study demonstrated the accuracy and stability of the prediction formula through the validation of a large sample size and a long time span. Wide ICA, iris concavity and anteriorly positioned ciliary body may have an effect on vault.

Comparison of accommodation and accommodative micro-fluctuation after implantable collamer lens and LASIK surgery for myopia.

BACKGROUND: To longitudinally analyze and compare the accommodative micro-fluctuation (MFs) and accommodative function between myopic patients after implantable collamer lens (ICL) implantation and laser in situ keratomileusis (LASIK). METHODS: Patients with good corrected visual acuity (20/20 or better) and underwent ICL (V4c) and LASIK for myopic-correction (ranging from - 3.50 to - 8.50 D) were recruited. Refraction, amplitude of accommodation (AMP), accommodative lag, higher-order aberration (HOA), and MFs were recorded before surgery and 1 and 3 months after surgery. The ACOMEREF automatic refractor was used to measure the high-frequency component (HFC) of the MFs, which suggested tension of the ciliary muscle. RESULTS: The study comprised 120 eyes. At 3 months after surgery, the manifest refractive spherical equivalent of the ICL and LASIK groups were - 0.11 and - 0.09 D, respectively (p = 0.46). HFC values were significantly higher at 1 month (p = 0.03) and 3 months postoperatively (p = 0.03) in the ICL group compared to that in the LASIK group. The ocular HOA of the ICL group was 1.08 ± 0.43 µm, which was lower than the LASIK group 1.45 ± 0.54 µm (p = 0.01). No significant differences in AMP and accommodative lag between groups were noted at 3 months postoperatively. There was a positive correlation between HFC and vault of the ICL lens (r2 = 0.14, p = 0.005). There were no correlations between HFC and ocular HOA and postoperative MRSE in the two groups (all p>0.05). CONCLUSIONS: The HFC increased significantly after an early period of ICL implantation compared to laser in situ keratomileusis for myopic correction, which indicated increased tension of the ciliary muscle, and had a positive correlation on the vault of the ICL lens; However, studies with longer follow-up time and more structural evaluation are needed.

Comparison of magnitude and summated vector mean of surgically induced astigmatism vector according to incision site after phakic intraocular lens implantation.

BACKGROUND: To compare the arithmetic mean (M-SIA) and the summated vector mean of surgically induced astigmatism (SVM-SIA) according to the incision site after phakic intraocular lens (Visian implantable collamer lens (ICL), STAAR Surgical) implantation. METHODS: This study comprised 121 eyes of 121 consecutive patients undergoing ICL surgery through a 3.0-mm temporal or superior clear corneal incision. The magnitude and the axis of corneal astigmatism preoperatively and 3 months postoperatively were measured using an automated keratometer. The M-SIA and the SVM-SIA were determined according to the incision site. RESULTS: The magnitude of corneal astigmatism significantly increased from 1.23 ± 0.59 D preoperatively to 1.46 ± 0.72 D postoperatively in the temporal incision group (Wilcoxon signed-rank test, P < 0.001), but it significantly decreased from 1.09 ± 0.36 D preoperatively to 0.86 ± 0.41 D postoperatively in the superior incision group (P < 0.001). The M-SIA was 0.48 ± 0.30 D, and the SVM-SIA was 0.23 ± 0.52 D at a meridian of 82° in the temporal incision group. The M-SIA was 0.57 ± 0.30 D, and the SVM-SIA was 0.47 ± 0.45 D at a meridian of 1° in the superior incision group. CONCLUSIONS: ICL implantation induces the M-SIA by approximately 0.5 D, but the SVM-SIA decreased to 50% and 80% of the M-SIA in magnitude through temporal and superior incisions, respectively. The direction of the SVM-SIA showed a tendency toward corneal flattening to the incisional site. It should be noted that the M-SIA is somewhat different from the SVM-SIA according to the incision site. Trial registration University Hospital Medical Information Network Clinical Trial Registry (000044269).

Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation.

BACKGROUND: To describe the very early vault changes in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault. METHODS: Eighty-three eyes from eighty-three subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed the postoperative vault at 2 h, 1 day, 1 week, and 1 month following implantation. Associations between the postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat keratometry (K), steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman's correlation analysis and stepwise multiple regression analysis. RESULTS: The mean vault values at 2 h, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 µm, respectively. Significant differences were found in the vault values at 2 h, 1 day and 1 week after the operation. The ICL size (ß = 0.942; p < 0.001), followed by horizontal STS (ß = -0.517; p < 0.001), crystalline LT (ß = -0.376; p < 0.001) and vertical STS (ß = -0.257; p = 0.017), significantly influenced the vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (µm) = -1369.05 + 657.121 × ICL size- 287.408 × horizontal STS - 432.497 × crystalline LT - 137.33 × vertical STS (adjusted R2 = 0.643). CONCLUSIONS: After ICL implantation, the vault decreased and then increased, but it did not return to the vault value 2 h after surgery. The ICL size, horizontal and vertical STS and crystalline LT are key factors for predicting postoperative vaulting.

Meta-analysis of clinical efficacy after FS-LASIK and ICL implantation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To compare the clinical effects of FS-LASIK and ICL implantation.<p>METHODS: From January 2015 to January 2020, used computer to search the clinical contrast test of FS-LASIK and ICL implantation published in CNKI database, Wanfang database, Chongqing VIP Chinese Sci tech journal full-text database, China Bioligy Medicine disc(CBMdisc), Cochrane Library, PubMed, MEDLINE and other databases,using rev-man5.3 statistical software for Meta-analysis and statistical processing.<p>RESULTS: Totally 11 studies were brought into the analysis, including 673 patients and 1 301 operative eyes. The results of Meta-analysis showed that there was no statistical significance in the safety, objective visual quality, spherical equivalent degree, cylinder, diopter of correction, trefoil aberration and coma aberration of FS-LASIK and ICL implantation after operation, but there was statistical significance in the effectiveness, total higher-order aberration, spherical aberration and contrast sensitivity of FS-LASIK and ICL implantation after operation.<p>CONCLUSION: Compared with ICL implantation, the total high-order aberrations and spherical aberrations of FS-LASIK are larger, and the contrast sensitivity is lower. The ICL implantation has more clinical-effect superioity than FS-LASIK, meanwhile it has reversibility and less complications.

Effect of the vault on corneal endothelial cells after microincision ICL V4c implantation without viscoelastic / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To evaluate the effect of the vault on corneal endothelial cells after implantation of central hole implantable lens(ICL)V4c without viscoelastic microincision.<p>METHODS: Prospective non-randomized controlled study. A total of 70 patients(137 eyes)with myopia who underwent ICL V4c implantation in our hospital from November 2017 to February 2018 were divided into low vault group(100μm<vault≤250μm, 37 eyes), medium vault group(250μm<vault≤750μm, 69 eyes)and high vault group(750μm<vault≤900μm, 31 eyes)according to the size of postoperative vault. After 1a of follow-up, the changes of corneal endothelial cell count and anterior chamber parameters were observed.<p>RESULTS:At 1wk after operation, the anterior chamber depth, anterior chamber volume and anterior chamber angle of the three groups were all decreased compared with those before operation(<i>P</i><0.05). There was no significant difference in corneal endothelial cell count among the three groups at different time points before and after surgery. The loss rate of corneal endothelial cells in the low vault group at 1wk, 3mo and 1a after surgery were about 1.2%, 1.5% and 1.7%, respectively. The loss rate of corneal endothelial cells in the middle vault group were about 0.5%, 0.7% and 1.0%, respectively. The loss rate of corneal endothelial cells in the high vault group were about 1.1%, 1.3% and 1.4%, respectively.<p>CONCLUSION:The vault in early period after ICL V4c implantation without viscoelastic microincision had no significant effect on corneal endothelial cells.

Agreement between anterior segment parameters obtained by a new ultrasound biomicroscopy and a swept-source fourier-domain anterior segment optical coherence tomography.

Purpose: To evaluate the agreement between anew UBM and an SS-OCT. Methods: The scans of the right eye of each volunteer were obtained using the two devices. Data were fitted and recorded including: central corneal thickness (CCT), aqueous depth (AQD) (the distance from endothelium to lens), angle-to-angle distance (ATA), lens thickness (LT), diameter of the lens in the horizontal direction (LDiaangle: distance between the sharp angles on both sides of the lens, LDiaarc: distance between the vertex of the circular arcs on both sides of the lens), anterior and posterior corneal radius (Rf and Rb). Results: 25 eyes were included in this study. It could be seen that the differences in CCT, LDiaangle, Rf measured by the two instruments were not statistically significant. Bland-Altman analysis plots of CCT, LDiaangle and Rf showed mean differences of 0.2 µm, 0.01mm and 0.0mm for the 2 devices, respectively. Conclusion: The values of CCT, LDiaangle and Rf obtained via two instruments were not clinically interchangeable and the AQD, ATA, LT, and Rb have poor agreement affected by accommodation. We can estimate the real lens diameter by subtracting 0.61 ± 0.43mm when the lens diameter can only be simulated with SS-OCT.

Comparison of objective optical quality between SMILE and V4c ICL implantation for correcting high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To compare the objective optical quality of high myopic patients between SMILE and V4c ICL implantation.<p>METHODS: This was a prospective control study. Thirty-eight patients underwent SMILE and thirty-two patients underwent V4c ICL implantation with high myopia were chosen for this study. Uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA)and refractive situation were evaluated preoperatively, at 1wk, 1mo, 3mo and 6mo postoperatively. The objective scattering index(OSI), strehl rate(SR)and modulation transfer function(MTF)cut off frequency were measured by the double-pass optical quality system at the same time.<p>RESULTS: No significant difference of spherical equivalent(SE), UCVA and BCVA was found between SMILE group and V4c ICL implantation group at all time points. At 1wk and 1mo after operation, the OSI values of two groups were significantly higher than pre-operation(<i>P</i><0.01). OSI values of two groups returned to baseline at 3mo after operation. The MTF cut off frequency of both groups decreased significantly at 1wk after operation(<i>P</i><0.05)and recovered to baseline at 1mo after operation, no significant difference was found between two group at all time points(<i>P</i>>0.05).<p>CONCLUSION: Both SMILE and V4c ICL implantation can obtain good visual acuity and objective optical quality.

Changes of ganglion cell-inner plexiform layer and retinal thickness in macular region after ICL implantation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the changes of ganglion cell-inner plexiform layer and retina thickness in myopic eyes after intraocular collamer lens(ICL)implantation using quantitative optical coherence tomography(OCT).<p>METHODS:A prospective study enrolled 41 myopic eyes of 26 patients which underwent ICL implantation(average age: 28.19±6.28 years). Aaxial length(AL), uncorrected visual acuity(UCVA), refractive diopter(RD), best corrected visual acuity(BCVA), intraocular pressure(IOP)and OCT were measured and compared in all patients before and after surgery. Optical coherence tomography(OCT)was used to image central retinal thickness(CRT)and ganglion cell-inner plexiform layer thickness(GCT). The changes between pre-and postoperative were analyzed by repeated measures analysis of variance(ANOVA). Least significant difference test was used to compare the specific time points after operation with those before operation.<p>RESULTS: Compared with the preoperative data, all the patients showed significant improvements in the postoperative UCVA and BCVA(<i>P</i><0.05). However, there was no statistical significance in IOP. CRT were 273.20 ±25.48, 274.07±27.64, 277.85 ±25.49, and 275.99 ±24.68μm before and after surgery, respectively, while GCT were 85.31 ±5.19, 88.95±6.87, 87.73±4.23, and 87.45±4.59μm, respectively, with statistically significant changes(all <i>P</i> <0.05). Among them, CRT increased in one month after operation, with statistical significance(<i>P</i><0.01). GCT increased in 1wk, 1mo and 3mo after operation, with statistical significance(<i>P</i><0.05). The changes of GCT in 1wk after operation was positively correlated with AL(<i>r</i>s=0.529, <i>P</i>=0.001).<p>CONCLUSION:ICL implantation for myopic eyes has good efficacy and safety, but macular area changes will occur after surgery, which need to be paid attention to.

Effect of posterior chamber introcular lens implantation on high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To evaluate the clinical efficacy of the posterior chamber intraocular lens(ICL)implantation for high myopia by the double-pass optical quality analysis system II(OQAS II).<p>METHODS: A total of 26 eyes of 52 patients with high myopia admitted to the First Affiliated Hospital of Anhui Medical University from December 2017 to December 2018 were selected. All patients underwent ICL implantation. Follow-up to obtain the best corrected visual acuity(BCVA)of all patients. And a series of parameters, such as uncorrected visual acuity(UCVA), object scatter index(OSI), modulation transfer function(MTF), Strehl ratio(SR)and Predicted VA of 100%,20% and 9%,were obtained before and 1wk,1 and 3mo after operation.<p>RESULTS: Compared with preoperative UCVA and BCVA, the 1wk, 1 and 3mo UCVA were better than preoperative and gradually improved, and the differences were statistically significant(<i>P</i><0.01). Compared with OSI, MTF, SR and Predicted VA 100%, 20% and 9% before operation, the situation improved at 1wk,1 and 3mo after operation, with statistical significance(<i>P</i><0.01).<p>CONCLUSION: ICL implantation can effectively correct high myopia and improve UCVA. Through OQAS II analysis, OSI was reduced after ICL implantation. The postoperative MTF, SR and Predicted VA of 100%, 20% and 9% higher than those before surgery. The visual quality of patients with high myopia was improved after ICL implantation.

Comparsion of corrected visual quality of two types of intraocular contact lens for high myopia / 眼科新进展

Objective To assess the optical quality after implantation of the intraocular contact lens with and without a central hole for high myopia.Methods A total of 23 patients (41eyes),including 11 patients (21 eyes) implanted with V4 ICL (V4 ICL group) and 12 patients (20 eyes) with V4 c ICL implantation (V4 c ICL group) were enrolled in this research.Six months after operation,slit lamp microscope was used to check the anterior segment,and LogMAR chart was to test uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA).Moreover,automatic refractometer was to measure the spherical equivalent (SE) and astigmatic diopter before and after the operation.OQAS parameters included objective scattering index (OSI),modulation transfer function (MTF),Stryrby (SR),OQAS values (OV100％,OV20％,OV9％) at different contrast level were examined.Results In both groups,the parameters of UCVA (logMAR),BCVA (logMAR),SE and astigmatic diopter at 6 months after operation were significantly improved compared with before operation,with significant difference (all P ＜ 0.05).There was no siguificant difference in the UCVA,BCVA,SE and astigmatic diopter between the two groups before operation and 6 months after operation (all P ＞ 0.05).Moreover,the values of MTFcutoff,SR,and OQAS visual parameters (OV100％,OV20％ and OV9％) at 6 months after operation were significantly higher than those before operation between the two groups,and the difference was statistically significant (all P ＜ 0.05),while OSI was lower than preoperative data,but there was no significant difference in OSI between the two groups (P ＜ 0.05).There was no significant difference in OQAS visual quality parameters,including OSI,MTFcutoff,SR,and OV100％,OV20％ and OV9％,between the two groups (all P ＞ 0.05).Conclusion It is safe and effective of the two types of intraocular contact lens implantation for correction of high myopia,and V4 c ICL can achieve the similar visual quality to the traditional V4 ICL.

Sudden Loss of Endothelial Cell Density 7 Years after Receiving an Implantable Contact Lens: A Case Report

PURPOSE: To report a case of decreased endothelial cell density 7 years after posterior chamber phakic intraocular lens implantation. CASE SUMMARY: A 45-year-old man with high myopia combined with astigmatism was treated with Toric implantable Collamer Lens (ICL) implantation. The patient's best corrected visual acuity was 0.7 in both eyes before the operation. After the treatment, his uncorrected visual acuity was 0.9 and corrected visual acuity was 1.0 in both eyes, indicating an improvement in visual function. Preoperative endothelial cell density measured 3,063 cells/mm2 in the right eye and 3,126 cells/mm2 in the left eye. At 5 years postoperatively, measurements were 2,897 cells/mm2 in the right eye and 2,974 cells/mm2 in the left, showing little change. However, a 6-year postoperative measurement of 2,198 cells/mm2 in the right eye and 2,803 cells/mm2 in the left showed a slight decrease in endothelial cell density in the right eye, and a follow-up measurement one year later displayed a rapid decline to 1,272 cells/mm2 in the right eye and 2,852 cells/mm2 in the left eye. The Toric ICL lens was removed from the right eye and phacoemulsification and posterior chamber intraocular lens implantation was performed. Two-month postoperative endothelial cell density was 1,257 cells/mm2 and endothelial cell damage from the operation itself was minimal. CONCLUSIONS: ICL implantation may cause complications related to corneal endothelial cells as well as glaucoma. Patients should receive regular follow-up examinations for endothelial cell density.

Risk Factors for Cataract Formation after Implantable Collamer Lens Implantation: Over a Mean 7.5-Year Follow-Up Period

PURPOSE: To determine the risk factors and incidence of cataract formation over a long-term mean follow-up of 7.5 years after type V4 implantable collamer lens (ICL) implantation. METHODS: We analyzed the preoperative, 3-month postoperative, 3-year postoperative, and last follow-up data of 228 eyes (118 patients) with mean preoperative spherical equivalent of -12.7 D and minimum postoperative follow-up of 3 years. Additionally, we determined the risk factors for cataract formation and calculated the 10.3 year cumulative cataract formation rate and 10.3 year cumulative cataract surgery rate using a survival curve. RESULTS: After type V4 ICL implantation with minimum follow-up of 3 years, the calculated 10.3 year cumulative cataract formation rate was 20% and actual cataracts developed in 34 eyes (14.9%). The 10.3 year cumulative cataract surgery rate was 12% based on a survival curve and actual cataract surgery was performed in 12 eyes (5.3%). The risk factors for cataract formation were age (odds ratio [OR] = 1.10, p = 0.00), preoperative spherical equivalent (OR = 0.90, p = 0.00), crystalline lens thickness (OR = 9.54, p = 0.00), axial length (OR = 1.33, p = 0.00), 3 months postoperative vault (OR = 0.50, p = 0.03), and existence of peripheral touch between ICL optic margin and crystalline lens at last follow-up (OR = 7.84, p = 0.00). CONCLUSIONS: We suggest one of the main risk factors for cataract formation after ICL implantation is decreased central vault and peripheral touch between ICL optic margin and crystalline lens.

Recurrent Occlusion of Laser Iridotomy Sites After Posterior Chamber Phakic IOL Implantation

We report a case of recurrent occlusion of laser iridotomy (LI) sites after a Visian ICL (Implantable contact lens version 4, Staar Surgical AG, Nidau, Switzerland) implantation. A 45-year-old woman had bilateral ICL implantation after placement of two peripheral LI sites in each eye to prevent pupillary block. At one month after the operation, severe narrowing or occlusion of four LI sites occurred. After this, although she received four additional LIs at postoperative months 1, 6, 9 and 10 in both eyes, the narrowing or occlusion recurred. Mild chronic anterior chamber inflammation was observed intermittently throughout the follow-up period. We performed clear lens extraction in both eyes (at postoperative month 11 in the left eye and month 26 in the right eye) due to recurrent occlusion of the LI sites and excess trabecular meshwork pigment deposition presumably caused by the four repeated LIs. Recurrent obstruction of LI sites can occur after ICL implantation. These problems were unresolvable despite four repeated laser iridotomies. The risks associated with anterior uveitis must be considered when planning an ICL implantation.

Long Term Effect of ICL Implantation to Treat High Myopia

PURPOSE: We have investigated the long term effect, stability, predictability and complication of ICL implantation to treat high myopia. METHODS: We investigated retrospectively in 176 eyes of 97 patients with spherical equivalent -11.91D (-6D~-23D) that were followed up for at least 6 months after ICL implantation. RESULTS: Mean spherical equivalent was maintained stable as -0.54D at 1 week post-operatively, and at -0.55D for 5years. There was high effect and predictability, with 92.3% of the eyes exhibiting a greater than or equal to best corrected visual acuity (BCVA), 83% of eyes having a post-operative uncorrected visual acuity (UCVA) of 0.5 or better, 91.3% having a post-operative refraction of -1.0D~+1.0D, and 86.4% having a post-operative refraction of -0.5D~+0.5D. The most common complications were glare and halos. With a temporary increase in IOP, significant endothelial cell loss was observed. Repositioning for a dislocated ICL was done in 3 eyes. Post-operative cataracts were found in 7 eyes (3.9%), which was a significant increase in incidence, but not surprising, as the patients were older and had lower Vaulting values. CONCLUSIONS: ICL implantation to treat high myopia was an effective surgery with good predictability and stability, and effective in both short term and long term follow-up periods.