Phakic intraocular lens implantation for the correction of refractive error has been adopted more extensively in China. The clinical efficacy has been promising and predictability and stability have a big advantage， but complications still occur from the clinical surgery. The safety of the operation is a prerequisite for the healthy development of the technology. This article reviews the literature spanning from the development of the phakic intraocular lens， the scientific basis of the technique， the customization of the surgical design， and the basic principles for preventing complications. The article presents the author′s viewpoint on commonly held suggestions for colleagues in order to improve the level of intraocular refractive surgery.

Objective  To investigate the change in the anterior chamber angle and to analyze its related factors of phakic posterior chamber implantable collamer lens （PPC-ICL） implantation. Methods  Twenty-six moderate and high myopic patients （45 eyes） who received PPC-ICL implants from March 2013 to April 2014 were included in this prospective study. The mean follow-up time was 4.3±3.2 months. Anterior chamber angle （ACA）， anterior chamber depth （ACD）， corneal curvature， and vault were measured with a Pentacam preoperatively and postoperatively. Corneal horizontal diameter and axial length （AL） were measured with IOLMaster. Visual acuity （VA）， spherical equivalent （SE） and intraocular pressure were recorded preoperatively and postoperatively. The data were analyzed with a matching t test， Wilcoxon signed rank test， Pearson correlation analysis， Spearman rank correlation and multiple regression analysis. Results  The ACAs at 3∶00 preoperatively and postoperatively were 43.23°±5.72° and 27.44°±5.24°. There was a significant difference between them（Z=-5.841， P＜0.01）. A positive correlation was found between the ACA change at 3∶00 and vault （r=0.556， P＜0.01） and preoperative ACA at 3∶00 （r=0.530， P＜0.01）. The correlation equation for postoperative ACA is ACApo=4.860-0.009 vault+0.621 ACApr （F=20.032， P＜0.01）. The ACAs at 9∶00 preoperatively and postoperatively were 42.40°±5.81° and 26.82°±4.73°. This is also significantly different （t=20.890， P＜0.01）. A positive correlation was also found between the ACA change at 9∶00 and vault （r=0.581， P＜0.01） and preoperative ACA at 9∶00 （r=0.626， P＜0.01）. The correlation equation for postoperative ACA is ACApo=5.767-0.008 vault+0.586 ACApr （F=24.775， P＜0.01）. Conclusion  The horizontal ACA narrowed significantly postoperatively. Preoperative ACA and vault were positively correlated with the change in ACA.

Objective  To analyze the safety of phakic posterior chamber implantable contact lens （PPC-ICL） implantation for extreme high myopia. Methods  This study was a retrospective analysis. Spheric PPC-ICL or toric PPC-ICL implantation was performed in 64 eyes of 32 patients with extreme high myopia. The spherical refraction of these patients was -10.0 to -19.0 D and cylinder refraction was 0 to -3.00 D. Uncorrected visual acuity （UCVA）， best-corrected visual acuity （BCVA）， slit-lamp examination， intraocular pressure （IOP）， topography examination， corneal endothelial cell count， refraction， anterior chamber depth （ACD）， the width of the angulus iridocornealis， PPC-ICL vault， and lens transparency were examined in these patients. The follow-up period was 2 years. A paired t test was used for data analysis. Results  At 2 years after surgery， all patients had better UCVA than before surgery. Forty-eight eyes （75%） had a refractive error between +1.0 and -1.0 D after surgery. Average intraocular pressure （IOP） before surgery was 15.0±3.6 mmHg and was 16.0±3.3 mmHg after surgery. There was no significant difference in IOP before and after surgery （t=0.474， P>0.05）. Preoperative ACD was 3.14±0.19 mm and was 2.70±0.26 mm postoperatively. There was a significant difference between preoperative and postoperative ACD （t=6.327， P＜0.05）. The width variation of the angulus iridocornealis between before surgery and after surgery was 13.20°±6.17°， and the difference was significant （t=6.686， P＜0.05）. There was no significant difference in the average number of corneal endothelial cells before surgery （2 844±266 cells/mm2） and 2 years after surgery （2 729±255 cells/mm2）. After surgery， 58 eyes （91%） had a suitable vault of the PPC-ICL from 250 to 750 µm. Two eyes of one patient had cataract complications but no other complications occurred after surgery. Conclusion  PPC-ICL implantation is safe for extreme high myopia.

Objective  To compare the clinical efficacy of two types of implantable lenses： a posterior chamber phakic refractive lens （PC-PRL） and a phakic posterior chamber implantable collamer lens （PPC-ICL） in two groups of patients with high myopia. Methods  This was a retrospective study. Ninety-eight myopic eyes of 51 high myopia patients were enrolled. Eighteen patients （33 eyes） were implanted with PC-PRLs （PRL group）， and the other 33 patients （65 eyes） were implanted with PPC-ICLs （ICL group）. Visual acuity， mainfest refraction， intraocular pressure， endothelial cell density， the distance between the posterior surface of the cornea to the lens， and contrast sensitivity （CS） were measured at least 2 years after the surgery. The occurrence of complications was also observed in the patients. An independent samples t test and Wilcoxon rank sum test were used for statistical analysis. Results  A comparison of uncorrected visual acuity after surgery between the PRL and ICL groups did not show a significant difference （Z=-1.871， P＞0.05）. Intraocular pressure was 12.03±2.61 mmHg in the PRL group and 13.35±3.37 mmHg in the ICL group （t=-1.197， P＞0.05）， while endothelial cell density was 2 185±516 cells/mm2 in the PRL group and 2 341±405 cells/mm2 in the ICL group （t=-1.168， P＞0.05）. There was no significant difference in a comparison of the distance between the posterior surface of the cornea to the lens， nor was there a significant difference between the arc height of 0.37±0.15 mm in the PRL group and 0.41±0.17 mm in the ICL group （t=-1.120， P＞0.05）. In addition， there was no significant difference in CS at all spatial frequencies. In terms of complications， in the PRL group， the lens deviated in 1 patient （1 eye） and cataract developed in 1 patient （1 eye）； in the ICL group， a cataract developed in 1 patient （2 eyes） and posterior surface artificial crystals came in contact with the anterior surface of the lens which added to the opacity of the anterior capsule in 1 patient （2 eyes）. Conclusion  There was no significant difference in the clinical efficacy between the PC-PRL and PPC-ICL implantation.

 Objective  To observe the efficacy， safety and visual quality of phakic posterior chamber intraocular lens implantable collamer lens （PPC-ICL） for correcting high myopia. Methods  In a prospective study of 50 eyes of 28 patients （14 eyes of 10 males and 36 eyes of 18 females） with an average spherical refractive error of -8.26±2.15 D and a spherical equivalent （SE） of -9.88±2.39 D. Thirty-six eyes were implanted with toric ICLs. The following indicators were compared： preoperative and postoperative uncorrected visual acuity （UCVA）， best corrected visual acuity （BCVA）， validity and safety analysis of the ICL surgeries， preoperative and 6 month postoperative wavefront aberrations， analysis of relevant indicators， and visual quality questionnaire scores six months after surgery. All patients were followed up for more than 6 months. Data were analyzed using a matched t test. Results  Preoperative UCVA （logarithm visual table， 5 vision） and 1 day， 1 week and 6 months after surgery were 3.82±0.08， 4.76±0.26， 5.02±0.13 and 5.03±0.10. Visual acuity 6 months after surgery improved compared to preoperative acuity （t=72.88， P＜0.05）. Compared to preoperative BCVA， UCVA 6 months after surgery equal to， increased 1 row， 2 rows and above for 16， 26， 4 patients， respectively， which accounted for 92% of the total number of eyes. The amount of residual diopters after 6 months of PPC-ICL implant was less than ±0.50 D， accounting for 96%. Preoperative higher-order wavefront aberrations， spherical aberrations， coma， and trefoil were 0.309±0.098 μm， -0.008±0.111 μm， 0.197±0.103 μm， and 0.142±0.076 μm； and after surgery were 0.320±0.152 μm， -0.114±0.117 μm， 0.026±0.534 μm， and 0.204±0.122 μm. Total higher-order aberrations and spherical aberrations increased， but the difference was not statistically significant. Coma was reduced （t=-3.454， P<0.05）， and trefoil increased （t=2.556， P<0.05）. The results of the visual quality questionnaire showed that all 28 patients （50 eyes） were satisfied with the surgery； other scores in descending order （the higher the score， the greater the satisfaction） were day cycling/driving ease， near vision， night vision， computer， close reading， night cycling/driving ease， visual fatigue， halos， glare， dry eye. Conclusion  ICL implants are a safe and effective surgical method for correcting high myopia， and all patients were satisfied with the surgery. The UCVA after surgery was obviously higher than the BCVA before surgery. Moreover， the procedure can also decrease coma， which can result in better visual quality.

Objective  To evaluate the efficacy， safety， stability and predictability of the Verisyse phakic iris-fixated intraocular lens （PIOL） for the correction of severe myopia. Methods  In this prospective cohort study， 37 patients （65 eyes）， aged from 17 to 44 years with severe myopia of -9.00- -27.00 D（-18.55±4.19 D）， were implanted with Verisyse phakic iris-fixated intraocular lenses from June 2005 to March 2012. Visual acuity， refraction， intraocular pressure， corneal endothelium， Verisyse IOL position， contrast sensitivity， glare sensitivity， surgical complications and poor visual symptoms were observed on 1 day， 1 week， 1 month， 3 months， 6 months， 1 year， 2 years， 3 years， and 5 years. Then safety index and efficacy index were obtained from BSCVA and UCVA. Results  The mean safety index and efficacy index were better than 1 at most times except at 1 month and 24 months. At 5 years， the mean manifest refraction was within 1 D of the attempted correction in 93% of eyes and within 0.5 D of the attempted correction in 84% of eyes. Near vision and intraocular pressure were not significantly different at 5 years. The mean loss of corneal endothelium was 3.0%±2.5%（0.07%-9.1%）. The distance from the corneal endothelium to the PIOL was 2.20±0.15 mm（>2 mm） and 0.73±0.08 mm（>0.5 mm） from the PIOL to the natural lens. There were statistically significant differences between preoperative and postoperative contrast sensitivity and glare sensitivity. Postoperative complications included 2 eyes with light inflammatory deposits on the PIOL surface， 1 eye with an oval pupil and 1 patient （2 eyes） with dislocated PIOLs. More than 80% of eyes had depigmented irises at the attachment sites. Conclusion  Verisyse IOL implantation for the correction of severe myopia is effective， safe， stable and predictable. It can be a supplement for corneal refractive surgery but follow-up is still required for the evaluation of long-term results.

Objective  To demonstrate the feasibility of visualizing the ciliary muscle using 1 310 nm wavelength spectral domain optical coherence tomography （OCT）. Methods  Experimental study. Three normal prepresbyopic subjects were recruited. 1 310 nm spectral domain OCT was used to image the temporal ciliary muscles of the left eyes in relaxed-accommodative and maximum-accommodative states. Custom software was used to correct and process OCT images. The thicknesses of the ciliary muscle 1 mm， 2 mm and 3 mm posterior to the scleral spur （CMT1， CMT2， CMT3） and the maximum thickness of the ciliary muscle （CMTM） were measured. The area of the ciliary muscle anterior to the CMT1 line served as CMA1. Similarly， the areas of the ciliary muscle between the CMT1 and CMT2 lines and between the CMT2 and CMT3 lines were defined as CMA2 and CMA3， respectively. Results  The high-resolution images of ciliary muscles were clearly captured in two different accommodative states. The boundaries of the cilairy muscle were easily visualized， and the custom software was feasible for the correction and analysis of the images. CMTM， CMT1 and CMT2 in the relaxed-accommodative state were thinner than in the maximum-accommodative state. In contrast， CMT3 in the relaxed-accommodative state was thicker than in the maximum-accommodative state. Similarly， CMA1 and CMA2， but not CMA3， were decreased in the relaxed-accommodative state as compared to the maximum-accommodative state. Conclusion  1 310 nm spectral domain OCT is a potentially promising technique for non-contact， non-invasive， real-time and high-resolution imaging of the ciliary muscle in human eyes.

Objective  To summarize and analyze the status of cataract surgery and the characteristics of cataract patients in the Shanghai Changning district from 2010 to 2013； to provide data for the future prevention of blindness． Methods  Data from patients and epidemiological characteristics for cataract surgery were collected from the Shanghai municipal disease prevention information management system. A chi-square test was used to compare the results from 2010 to 2013 in Changning district. Results  There were 36 854 cataract removal operations performed in Changning district from 2010 to 2013 with 93.78% of the patients over sixty years of age. Females accounted for 58.88%， which was slightly higher than males. Age-related cataract was the main type of cataract in 97.81% of the patients. Phacoemulsification was the main surgical technique used， accounting for 99.72% of the surgeries， and IOL implants accounted for 99.87%. Conclusion  The cataract surgical rate in the Shanghai Changning district was high up until 2013. Phacoemulsification is the main method for treating cataract.

Objective  To research the recovery of the visual cortical function mediating visual motion perception in ametropic amblyopia after regular amblyopia treatment using 3.0 Tesla functional MRI （fMRI）. Methods  In this prospective study， blocks-designed fMRI experiment was performed on nine children with first was diagnosed as ametropic amblyopia， and review fMRI after one week， two weeks and one month. During the study， the patients were asked to view stimuli through rotating the checkerboard， which contrast ratio approach to 100% and frequency approach to 8 Hz， Functional MRI data were processed by using SPM8 which based on the Matlab 7.12. The matrix data of each treatment stage were acquired by hypothesisdriven research， and before and after self-control study （matched t-test） was performed in each group to acquire average cerebral cortex activated functional images data. The different mapping between each group during visual motion stimulus was also acquired. Results  The functional area that is bilateral occipital lobe （Mean t of the right BA18=1.236 1； Mean t of the left BA18=1.521 1； Mean t of the right BA19=1.684 5； Mean t of the left BA19=1.591 7， P<0.005） and the visual association area （V5） （The right BA37 was activated and Mean T=1.201 4； The right BA21 was activated and Mean t=1.145 0， P<0.005） expanded in different levels after amblyopia treatment two weeks； After four weeks， the bilateral occipital lobe （Mean t of the right BA18=1.002 4； Mean t of the left BA18=1.743 1； Mean t of the right BA19=1.225 3； Mean t of the left BA19=1.181 3， P<0.005） showed activation on the small area compare with two weeks ago. Conclusion  In the early functional training of the older children′s ametropic amblyopia， reconstruction the visual cortical function mediating visual motion perception was more difficulty and unstable.

Objective  To objectively analyze ocular torsion during inferior oblique overaction （IOOA） with or without V-pattern exotropia and to explore the role of master eye and slave eye and the difference between them. Methods  In this prospective study， based on whether V-pattern strabismus occurred， an experimental group of 51 exotropic patients with IOOA were divided into two groups： 21 cases of IOOA and 30 cases of IOOA with V-pattern. Thirty cases for study of the foveal disc torsional angle （FDA） of the master eye and slave eye without strabismus were selected as the control group. All of the patients in the experimental group underwent inferior oblique weakening and horizontal strabismus surgery and were followed up postoperatively for one month. The FDAs of the master eye and slave eye of the two groups were compared with those of the control group. Data were analyzed using ANOVA and Fisher′s exact test. Results  One month after surgery， the IOOA of the 51 patients with exotropia was no longer apparent， and V-pattern strabismus disappeared in all the patients. There were statistically significant differences in the FDAs of the master eyes between the group with IOOA with V-pattern exotropia and the control group preoperatively （P<0.05）， but no statistically significant differences between the group with IOOA and the control group preoperatively （P>0.05）. There were no statistically significant differences in the FDAs of the master eye between the two groups and the control group postoperatively （F＝0.610， P>0.05）. There were no statistically significant differences in the FDAs of the slave eye between the two groups and the control group before or after the operation （F=1.007， 1.383， P>0.05）. The case of encyclovergence in two groups was increasing. The improvement ratio of near distance stereoscopic is 57% in IOOA group， and 60% in IOOA with V-pattern group. There was no statistically significant difference between two groups （P>0.05）. Conclusion  Excyclovergence in the master eye with IOOA with V-pattern strabismus can be more apparent than in the normal persons. Excyclovergence in the slave eye in IOOA is not as obvious.

Objective  To analyze the clinical characteristics and prognosis of an acute intraocular pressure （IOP） spike posterior to the Nd∶YAG laser capsulotomy in patients with posterior capsular opacification. Methods  Medical charts of 16 patients who underwent Nd∶YAG laser capsulotomy and presented with an IOP spike （≥40 mmHg， 1 mmHg=0.133 kPa） after treatment in Beijing Tongren Eye Center from January 2012 to November 2013 were reviewed retrospectively. Main investigative aspects included age， gender， cataract subtypes， pre- and post-treatment visual acuity and IOP， Nd∶YAG laser parameters used in the treatment， the management of the acute IOP elevation and the clinical outcomes. Results  Sixteen patients （10 males and 6 females） were enrolled in this retrospective study， with an average age of 22.5±11.8 years. Mean IOP level was 17.3±3.5（11-22）mmHg before laser capsulotomy. Two of the patients were receiving anti-glaucoma medication before the laser treatment. IOP increased immensely 3.6±1.3（2-6） hours after posterior laser capsulotomy， with an average of 44.1±4.5（40-57）mmHg. IOP was controlled in 12 patients after intensive anti-glaucoma medication. Nevertheless， the other four patients still had high IOP above 40 mmHg after medical intervention， and paracentisis was performed to reduce ocular hypertension. Except for one patient who still had an IOP of 31 mmHg， IOP was under control （≤21 mmHg） in all other patients by the second day. On follow-up day 3， IOP was 14.7±4.1（11-19）mmHg. IOP remained stable and was 16.3±2.8（12-20）mmHg on the last follow-up visit， which was not statistically different from baseline （t=1.240， P>0.05）. Conclusion  Intensive anti-glaucoma medication and/or paracentisis is safe and effective to reverse the IOP spike in patients with posterior capsular opacification posterior to Nd∶YAG laser capsulotomy. And the prognosis is excellent.

Objective  To evaluate the safety and efficacy of bevacizumab application as an adjuvant therapy for pterygium excision surgery. Methods  In this prospective clinical trial， 95 eyes with unilateral nasal pterygium underwent pterygium excision surgery combined with limbal stem cell autografting， and were assigned into 3 groups at random： group A （32 eyes） did not receive a bevacizumab injection； group B （34 eyes） received a single dose of subconjunctival bevacizumab injection （2.5 mg/0.1 ml） intraoperatively； group C （29 eyes） received subconjunctival bevacizumab injection （2.5 mg/0.1 ml）， one dose intraoperatively and another 2 weeks postoperatively. Patients were followed for 6 months. A one-way analysis of variance， chi-square test， Mann-Whitney and Kruskall-Wallis tests were used for statistical analysis. Results  At the end of the study， all stem cell autografts in 3 groups remained alive， with no complications of missing corneal epithelium， erosion or corneal thinning occurring. Pterygium recurrences were only observed in 4 cases in group A， and the occurrence was statistically significant （H=7.50， P<0.05）. No significant difference was found in the clinical efficacy between patients receiving single or double doses of subconjunctival injection. Conclusion  Bevacizumab injection combined with limbal stem cell autografting in pterygium excision surgery can effectively inhibit the recurrence of pterygium with no apparent complications. Multiple injections do not yield a better clinical outcome compared to a single dose.

Objective  To analyze the retinal microvascular characteristics in the ocular fundus of Takayasu arteritis patients. Methods  Fifteen female patients with Takayasu arteritis with an average age of 26.0±9.0 years were enrolled in a cases series study. All patients received routine ophthalmologic examinations， including visual acuity， refraction， intraocular pressure， slit lamp， and fundus photography. Twelve patients underwent fundus fluorescein angiography （FFA）. Observation was mainly made on the performance of FFA in order to analyze the characteristics of their fundus changes. Results  Of the 15 patients， 29 eyes （97%） presented with disease and 1 eye （3%） was normal. Twenty-four eyes （80%） showed ischemic retinopathy， and 5 eyes （17%） showed hypertensive retinopathy. Microaneurysm is the early manifestation of ischemic retinopathy with characteristics such as wide distribute peripherally and mid-peripherally with almost the same size and homogeneous distribution， yet there is a tendency for dense distribution towards the peripheral retina. A diffuse non-perfusion area presents progressive development from peripheral areas towards the optic disk. Extensive arteriovenous anastomosis appears at the edge of the non-perfusion area， demonstrating a characteristic corollaceous shape. In the advanced stage， new vessels on the disc are very common， without new vessels elsewhere. Conclusion  Ocular fundus manifestation of Takayasu arteritis can mainly be categorized into two types： ischemic retinopathy and hypertensive retinopathy. While the former is more common， there are some characteristic changes in chronic arterial ischemia retinopathy. Both can occur in one eye simultaneously.

Acute intraocular pressure （IOP） elevation is one of the key conditions responsible for visual dysfunction. Several animal models have demonstrated that elevated IOP gradually induces retinal structure and function damage from the inside to the outside. Mechanical compression and ischemia contribute to the alteration of the cellular microenvironment， which eventually cause the apoptosis of retinal ganglion cells. Different levels and duration of IOP result in different degrees of functional and structural damage. This article reviews the progress in current research about the influence of acute IOP elevation on visual function and structure.