The implantable collamer lens （ICL） has become an important technology for intraocular refractive surgery. With the improvement and innovation of material， design and applications， the ICL has good efficacy and predictability， long-term safety and stability， manageable complications and reversibility. More and more refractive surgeons are paying attention to it. This article reviews the material characteristics， the latest designs for the ICL and its clinical applications， visual quality and future development.

Objective  To investigate the agreement and correlation between preoperative simulated vaults （SV） measured by 50 MHz full-scale ultrasound biomicroscope and postoperative real vaults in phakic posterior chamber implantable collamer lens （PPC-ICL） implantation. Methods  In this self-control study， 21 high myopia patients （37 eyes） undergoing PPC-ICL implantation were included at the Eye and ENT Hospital of Fudan University from May to July in 2014. The mean age was 30.0±9.0 years and the mean spherical equivalent was -15.60±5.74 D. Based on the preoperative examination， the correct diopters and sizes of the PPC-ICL can be determined. Then the simulated postoperative images， simulated lens， positions and SV were achieved using a Compact Touch STS UBM. One month after implantation， the real vaults were measured by UBM and Pentacam， which were recorded as VUBM and VPentacam， respectively. The correlation and agreement for the three vaults were analyzed with Pearson correlation analysis and Bland-Altman， respectively. Results  SV， differed significantly from VUBM and VPentacam （t=6.660， 9.658， P<0.01）. Correlation analysis showed that there were moderate correlations between SV and VUBM， SV and VPentacam （r=0.508， 0.557， P＜0.01）. For the postoperative vaults， the agreement between the vaults measured by the Compact Touch STS UBM and those measured by Pentacam was strongest [95% Limit of Agreements （LoA）=-0.07-0.22 mm]. In contrast， the 95% LoA showed clinically significant differences between SV and VUBM and between SV and VPentacam （95% LoA=-0.19-0.66 mm， -0.07-0.70 mm）. Conclusion  Compact Touch STS UBM can replace Pentacam clinically in postoperative vault measurements. There is still a certain gap between the SV measured by the Compact Touch STS UBM and the actual postoperative vaults.

Objective  To assess the effect on anterior chamber angle， corneal endothelial and adjacent tissue after implantation of phakic posterior chamber implantable collamer lens （PPC-ICL） for the correction of high myopia. Methods  In this prospective， nonrandomized clinical study， 106 consecutive eyes of 58 patients with high myopic received ICL implantation between January 2011 and June 2013 in the Ningxia Eye Hospital. Uncorrected visual acuity（UCVA）， best corrected visual acuity（BCVA）， intraocular pressure， corneal endothelial cell count were measured preoperatively and at 1 month， 6 months and 12 months postoperatively. The ultrasound biomicroscopy （UBM） was used to observe the depth of anterior chamber （ACD） vault， angle opening distance 500 microns from the scleral spur （AOD500）， trabecular-iris angle （TIA） at point 2， 4， 8 and 10 respectively. The repeated measurement ANOVA was used to analyzed statistical data. Results  The postoperative UCVA was equally or higher compare with preoperative BCVA in all patients. Intraocular pressure and corneal endothelial cell count were no statistically significant difference between pre- and postoperative （P>0.05）. The postoperaive ACD， AOD500 and TIA value were decreased significantly than preoperative at 1 month （F=12.372， 21.393， 22.076， 21.154， 21.763， 19.471， 19.823， 19.836， 19.247， P<0.05）. But there were no statistically significant difference of ACD， AOD500， vault and TIA  between 1-month and 6-month， 12-month postoperatively. No pupillary block glaucoma or anterior capsule opacification occurred during the follow-up. Conclusion  The structure of anterior chamber angle was stable and corneal endothelial cell was no obvious decrease postoperatively during 1 year follow-up.

Objective  To assess the indication， effectiveness and stability of phakic posterior chamber toric implantable collamer lens （PPC-TICL） repositioning operation on PPC-TICL axis rotation. Methods  A retrospective study on 33 PPC-TICL eyes with PPC-TICL axis rotation more than 10°has been performed， 12 eyes have been operated PPC-TICL repositioning in three months postoperation was operation group and 21 eyes only have been performed follow-up examination was control group. The observation indices was studied including LogMAR vision， refractive， PPC-TICL axis rotation， vault value， corneal endothelium， intraocular pressure and subject vision assessment scales. The indices of pre-reposition in operation group and control group post-implantation 3 months follow-up were compared with independent-samples t test. To determine the effect of reposition， the indices of pre-reposition， post-reposition 3 months follow-up and 12 months follow-up in operation group have also been compared through repeat measured ANOVA. Results  To compare pre-reposition， post-reposition on 12 months follow-up and control group， the indices including： UCVA， mean manifest refractive cylinder， PPC-TICL axis rotation and subject vision assessment scales have significant difference （t=2.569， -5.789， 6.297， 13.061， -2.063， 3.162， -12.973， -2.065， P＜0.05）， nevertheless， BCVA， mean manifest refractive spherical equivalent， vault value， intraocular pressure and corneal endothelium have no significant difference. To compare pre-reposition， 3 months post-reposition and 12 months post-reposition， there were significant difference on visual outcome， mean manifest refractive cylinder， mean manifest refractive spherical equivalent， PPC-TICL axis rotation and subject vision assessment scales（F=30.839， 51.118， 5.127， 117.320， 62.347， P＜0.05）. Meanwhile， there was also significant difference between pre-reposition and 3 months post-reposition or between pre-reposition and 12 months post-reposition in reposition group. Conclusion  The retrospective study proved the effect and stability of TICL reposition operation after PPC-TICL axis large-angle rotation， early PPC-TICL reposition could result in perfect prognosis.

Objective To evaluate the changes in binocular vision after phakic posterior chamber implantable collamer lens （PPC-ICL） implantation for high myopia. Methods This self-control study included 84 eyes of 42 patients with high myopia who underwent PPC-ICL implantation surgery. Simultaneous perception， fusion range， and distance and near stereopsis were tested before and 6 months after surgery with a synoptophore and stereogram designed by Yan Shaoming. Results There was no significant difference in simultaneous perception before surgery compared to 6 months after surgery， while the differences in fusion range and distance stereopsis were statistically significant （χ²=0.357， P<0.01 and χ²=0.276， P<0.05）. There were no significant differences in foveal stereopsis and peripheral stereopsis before surgery compared to 6 months after surgery， but there was a significant difference in stereo blindness （χ²=0.279， P<0.05）. Conclusion Simultaneous perception， fusion range， and distance and near stereopsis after PPC-ICL implantation obviously improved compared to measurements taken before surgery.

Objective  To investigate the effect of phakic posterior chamber implantable collamer lens （PPC-ICL） implantation surgery on the accommodative status of eyes with high myopia. Methods  The study included 30 eyes of 30 22-30 years old patients with high myopia. All patients underwent PPC-ICL surgery in the West China Hospital of Sichuan University. Monocular accommodative amplitude， positive and negative relative accommodation and accommodative facility were investigated before surgery and 1 month and 3 months after the surgery. The results were analyzed by repeat measured ANOVA. Results  Monocular accommodative amplitude had increased 3 months after surgery （F=57.909， P<0.05）. Accommodative facility had also increased 3 months after surgery （F=18.663， P<0.05）. However， there were no differences in positive and negative relative accommodation at the three time points. Conclusion  PPC-ICL implantation surgery does not cause adverse effects on accommodative function. After PPC-ICL implantation surgery， accommodative amplitudes and accommodative facility increase. But there is no significant effect on positive and negative relative accommodation.

Objective  To compare visual quality after implantation of either a multifocal toric intraocular lens （IOL） or a monofocal toric IOL. Methods  This retrospective case-control study was comprised of 32 eyes of 27 patients with more than 1.0 D of preexisting corneal astigmatism. Ten eyes of 8 patients were implanted with Acrysof IQ Restor toric IOLs （SND1T group） and the other 22 eyes of 19 patients were implanted with Acrysof IQ toric IOLs （SN6AT group）. Uncorrected （UDVA） and corrected （CDVA） distance visual acuities， uncorrected （UNVA） and corrected （CNVA） near visual acuities， residual astigmatism， IOL rotation， contrast sensitivity （CS）， modulation transfer functions （MTF） and total eye wavefront aberrations were evaluated for 6 months postoperatively. Data were analyzed using an independent-samples t test and repeated-measures ANOVA. Results  The UNVA in the SND1T group was better than that in the SN6AT group at the postoperative time points （t=11.683， 8.252， 7.384， P<0.01）. At 6 months postoperatively，the CS with glare at low spatial frequencies （3 c/d） in the SND1T group was significantly lower than that in the SN6AT group （t=2.086， P<0.05）. MTFs were significantly lower in the SND1T group than that in the SN6AT group with 3-mm pupils at middle spatial frequencies （5， 10 c/d） （t=2.050， 2.078， P<0.05）. There were no statistically significant differences in UDVA， CDVA and CNVA throughout the postoperative time points between the 2 groups. At 6 months postoperatively， the difference in corneal astigmatism between preoperative and postoperative measurements， the mean IOL axis rotation， CS without glare and with glare at residual spatial frequencies， MTF with 3-mm pupils at medium and high spatial frequencies and with 5-mm pupils at all spatial frequencies， total eye wavefront aberrations， total higher-order aberrations， spherical aberrations and coma under 3- and 5-mm pupils were not statistically significant between the 2 groups. Conclusion  Compared with the monofocal toric IOL， the multifocal toric IOL can provide excellent overall visual acuity，effective astigmatic correction and favorable visual quality.

Objective To investigate the distribution of refractive errors （RE） after age-related cataract surgery and the potential preoperative ocular biometric parameters that may influence RE. Methods A retrospective study that included 197 age-related cataract patients （197 eyes） was carried out. Anterior chamber depth （ACD）， anterior chamber volume， horizontal corneal diameter （white-to-white， WTW）， and corneal spherical aberrations were measured by a Pentacam， then the WTW/ACD ratio was calculated. Corneal power （mean K value） and axial length were measured by an IOLMaster， and postoperative refraction was predicted by an SRK-T formula. Subjective refraction was examined 3 months after cataract surgery， and the difference between the predicted value and subjective refraction was calculated as RE. Single factor and multiple linear regression analyses were performed to study the relationship between RE and the preoperative biometric parameters. Patients were divided into a hyperopic or myopic error group， based on an RE larger than +0.50 D or less than -0.50 D， respectively. Independent t tests were performed to compare the differences in biometric parameters between the two groups. Results The mean RE after the surgeries was -0.50±0.92 D， including 88 cases of myopic error （44.7%） and 28 cases of hyperopic error （14.2%）， with mean REs of -1.31±0.60 D and +0.86±0.29 D， respectively. Single-factor regression analyses showed both WTW （β＝0.473， F=12.49， P<0.01） and ACD （β＝0.286， F=4.57， P<0.05） could significantly influence postoperative RE， while the influence of WTW/ACD was close to significance （β＝-0.121， F=3.59， P=0.06）. Multiple linear regression showed only WTW entered the final model （F＝12.49， P<0.01）. A significant difference in mean WTW/ACD ratios was noticed between the myopic （4.91±1.20） and hyperopic （4.48±0.65） error groups （t=2.42， P<0.05）. Conclusion Preoperative ACD and WTW can influence postoperative refractive error in age-related cataract patients. The WTW/ACD ratio can be considered as a morphological indicator to describe the anterior chamber， which may be useful to predict RE after cataract surgery.

Objective  To evaluate the safety and efficacy of laser in situ keratomileusis （LASIK） for high and ultra-high myopia 10 years after surgery. Methods  In this retrospective study， 41 patients （80 eyes） who underwent LASIK from October 2002 to May 2004 for myopia were recently reexamined. Data for uncorrected visual acuity （UCVA）， refractive error， and best corrected visual acuity （BCVA） were evaluated as well as the degree of regression， the percentage of UCVA≥5.0， and loss of ≥2 lines of BCVA. Patients were divided into two groups based on average preoperative spherical equivalent： group A： -6.00~-10.00 D （44 eyes） and group B： >10.25 D （36 eyes）. A t test was used for normally distributed data. Attributes data were analyzed using a χ² test. A Pearson correlation coefficient was used for correlation analysis. Results  A UCVA of ≥4.7 was achieved in 85% of the patients and ≥5.0 in 45% among the 80 eyes. No patients lost ≥2 lines of BCVA. The percentage of UCVA ≥1.0 in group A was significantly higher than that in group B （χ²=5.518， P<0.05）. The mean spherical equivalent was -0.91±1.43 D 10 years after LASIK surgery， which differed significantly from the preoperative data of -10.10±2.42 D （t=-28.196， P<0.01）. The percentage of regression ≤0.50 D was higher in group A than group B （χ²=6.865， P<0.05）. A regression ≥1.00 D was obtained in 30 eyes after 10 years. A positive correlation was found in these 30 eyes between the degree of regression and the difference between the actual and expected corneal thickness （r=0.706， P<0.01）. Conclusion  LASIK for high myopia is an effective and safe long-term procedure， but it is slightly less predictive in patients with ultra-high myopia.

Objective  To compare the effects of different delivery methods of non-steroidal anti-inflammatory drugs （NSAIDs） on changes in macular thickness after uncomplicated micro-incision phacoemulsification using spectral domain optical coherence tomography （OCT）. Methods  In this prospective study， 129 patients were randomly divided into three groups. After surgery， group A （41 cases） received no NSAIDs， group B （44 cases） received pranoprofen and group C （44 cases） received pranoprofen combined with ibuprofen （sustained-release capsules）. All patients were treated with topical tobramycin and dexamethasone postoperatively. OCT measurements were performed preoperatively and at 1 day， 1 week and 6 weeks postoperatively. The mean macular thicknesses of 9 sectors were analyzed with the macular thickness mapping protocol of the OCT. Data were analyzed using one-way ANOVA， repeate measured ANOVA， and Pearson correlation analysis. Results  Compared with preoperative acuity， there was a significant increase in best corrected visual acuity （BCVA） after surgery in all 3 groups. However， there was no correlation between changes in macular thickness and BCVA. At 1 day after surgery， no significant differences in retinal thickness were found among the 3 groups. At 1 week after surgery， the 1-mm central subfield （CSF） thickness showed no significant difference among the groups. However， there was a significant difference in the retinal thickness of the parafoveal area （A2） between groups A and C （P<0.05）. Furthermore， the thicknesses of the CSF and some parafoveal areas in group A were significantly greater than those in groups B and C （P<0.05）. Conclusion  NSAIDs may have some effects on alleviating macular thickening after surgery. To some extent， oral NSAIDs are effective during the early stage after surgery.

Objective  To evaluate the effectiveness of the reconstruction of the lacrimal passage combined with the Ritleng intubation system in the treatment of childen′s obstruction of the lacrimal duct secondary to conjunctivitis. Methods  In this retrospective cases-series study， 43 children （49 eyes） who ranged in age from 8 months to 11 years old participated. All children underwent reconstruction of the lacrimal passage combined with the Ritleng intubation system under general anesthesia. The follow-up period was from 6 to 12 months after surgery. The tubes were left in place between 2 and 6 months depending on the situation. After extubation， clinical success was defined as lacrimal patency， but sometimes there was some lacrimal resistance along with tear drainage. The surgery was considered ineffective if the tear duct was not penetrated. Results  Based on the obstruction site， all the children were divided into 4 types： lacrimal canalicular obstruction （9 cases）， lacrimal duct obstruction （12 eyes）， obstruction of the nasolacrimal duct （4 eyes）， and complex duct obstruction（24 eyes）. After extubation， the overall success rate was 65%（32/49） and the melioration rate was 20%（10/49）. On the other hand， the procedure was ineffective in 7 eyes （14%）. Conclusion  The reconstruction of the lacrimal passage combined with the Ritleng intubation system is a safe and effective procedure for the treatment of secondary nasolacarimal duct obstruction.

Objective  To analyze the changes in pregnancy-induced hypertension syndrome （PIHS） using optical coherence tomography （OCT）. Methods  A prospective study was conducted to investigate 132 patients （264 eyes） with PHIS who consented to eye examinations that included visual acuity， refraction， slit lamp examination， fundus examination， and OCT. Chi-square tests and Spearman correlation analysis were used to investigate the statistical correlation between retinal detachment seen in OCT exams and patients′ general information （blood pressure， edema， proteinuria）. Results  ①A fundus examination showed that 232 eyes （87.9%） with PHIS had fundus lesions， including stage I in 16 eyes （6.9%）， stage II in 31 eyes （13.4%）， and stage Ⅲ in 185 eyes （79.7%）. ②OCT examination showed that 172 eyes （65.2%） had abnormalities， including neurosensory serous retinal detachment in 94 eyes （54.6%）， pigment epithelium and IS/OS layer changes in 40 eyes （23.3%）， and optic disc edema， retinal hemorrhage and other changes in 38 eyes （22.1%）. ③Since hypertension， edema， and proteinuria are risk factors for retinal detachment， a higher blood pressure leads to more severe proteinuria and edema， which are correlated with a higher risk of retinal detachment （r=0.156， 0.208， 0.296， P<0.05）. Conclusion  As a non-contact， non-invasive tomographic imaging technique for severe PIHS， OCT provides objective and accurate inspection images that detect changes in the fundus.

Objective  To explore the efficacy of a modified technique with Ahmed glaucoma valve （AGV） implantation in the treatment of refractory glaucoma. Methods  This retrospective study included a total of 47 eyes of 46 refractory glaucoma patients who underwent a modified Ahmed glaucoma valve implantation in Wuhan Aier Hospital from January 2011 to December 2013. The sutureless AGV implantation technique was as follows： The drainage plate was secured between the episclera and Tenon′s capsule with no suture placement. An approximate 6 mm radical scleral tunnel was made from 5 mm to the limbus and near the limbus respectively， and the drainage tube was inserted through the tunnel， followed by a sclerotomy at the limbus through which the tube was introduced into the anterior chamber. The extraocular portion of the tube was covered. Best corrected visual acuity （BCVA）， intraocular pressure （IOP） and the number of anti-glaucoma medications before and after the surgery and postoperative complications were evaluated. Patients were followed up and postoperative data was obtained at 1 week， 1 month， 6 months， and then at 6-month intervals after surgery. Comparsions of IOP at different time points after surgery were performed by using repeat mesured ANOVA； while a paired nonparametric rank sum test was used to compare the number of glaucoma medications， and visual acuity preoperatively and postoperatively or at the last follow-up. Results  Visual acuity was not significantly different between pre-operation and the final follow-up （Z=1.826， P＞0.05）. Preoperative IOP varied from 15 to 69 mmHg， and IOP was between 9 and 23 mmHg at the final follow-up. The mean IOP was significantly reduced from a preoperative 43.26±8.14 mmHg to a postoperative 15.3±5.9 mmHg （F=12.16， P<0.05）. The number of anti-glaucoma medications was significantly reduced from 4 at preoperation to 1 postoperatively （Z=7.32， P<0.05）. At the last visit， the complete success rate of the AVG implantation reached 72.3%， and the conditional success rate hit 87.2%. Postoperative complications included anterior chamber hemorrhage， obstruction of the drainage tube， a shallow anterior chamber and encapsulated cystic blebs around the plate， which could all be controlled with additional treatments. Conclusion  The modified Ahmed glaucoma valve implantation is confirmed as an effective way to treat refractory glaucoma， and it is worth being used routinely in the clinic because it is a less complicated procedure， reduces surgery time and has fewer postoperative complications.

The use of collagen cross-linking is being developed continually due to its significance in the improvement of the mechanical strength of collagen fibers and its role in stopping myopia progression. This article discusses the advantages and disadvantages of traditional scleral UVA riboflavin cross-linking and blue-light riboflavin scleral cross-linking. The trend toward blue-light scleral cross-linking in replacing UVA cross-linking to prevent the progression of myopia is described in this review article.