As one of the most commonly performed operations， cataract surgery is generally successful in the majority of patients， but the great diversity in cataracts and patients means that not all surgeries present the same level of complexity. The complication rate is likely to increase with the complexity of the case， such as hard and mature nuclei， subluxated lenses， small pupil， high myopia， glaucoma and other diseases causing changes in ocular structres. It is better to understand correctly the characteristics of various types of the complicated cataract and take the appropriate surgical approach as much as possible to reduce the complications.

Objective  To compare the accommodation amplitude after different aspheric monofocal posterior chamber intraocular lenses （IOLs） implantation. Methods  A prospective clinical study comprised 102 eyes of 102 patients who underwent phacoemulsification and intraocular lens implantation in Tianjin Medical University Eye Hospital from August 2010 to August 2011. Patients were divided into 3 groups according to the type of  IOLs that implanted： Group Rayner were implanted with Rayner Superflex 920H  IOL （Rayner）； Group SN60WF were implanted with Acrysof IQ SN60WF IOL （Alcon）； Group SN60AT were implanted with Acrysof NATURAL SN60AT IOL （Alcon）. At 6 months postoperatively， uncorrected visual acuity， best corrected visual acuity， distance corrected near visual acuity were evaluated. Spherical aberration was measured by Hartmann-Shack wavefront sensor. Patients′ subjective amplitude of accommodation was measured by integrated refractometer adjustment feet； while the objective amplitude of accommodation was measured by WR-5100 automatic computer Refractometer （GrandSeiko）. Statistical analysis of count data and measurement data were done separately by the chi-square test and variance analysis. Pearson correlation was performed to analyze the association between parameters. Results  The subjective amplitude of accommodation in the 3 groups were 2.00±0.58 D， 2.26±0.60 D， 2.29±0.48 D， respectively， while the objective amplitude of accommodation in the three groups were 0.87±0.37 D， 1.01±0.38 D， 1.04±0.37 D， respectively. There was no statistically significant difference between the subjective and objective amplitude of accommodation in the 3 groups （Fsub=2.662， Psub=0.075； Fob=1.925， Pob=0.151）. When the pupil diameter was 3 mm， the spherical aberrations of the three groups were  0.08±0.04 μm， 0.05±0.04 μm， 0.14±0.05 μm， respectively. The difference of spherical aberration among the three groups was statistically significant （F=45.780， P<0.01）. No correlation was found in the spherical aberration with subjective or objective amplitude of accommodation （rsub=0.056， Psub=0.576； rob=0.095， Pob=0.343）. Conclusion  Compared with the implantation of Acrysof SN60AT spherical intraocular lens， the implantation of the Acrysof SN60WF aspheric intraocular lens and Rayner Superflex 920H aspheric intraocular lens do not affect the amplitude of accommodation significantly. No correlation is found between spherical aberration and subjective or objective amplitude of accommodation.

Objective  To evaluate the visual acuity and the rate of spectacle independence after implantation with ReSTOR multifocal intraocular lenses （MIOLs） in myopes， emmetropes and hyperopes. Methods  It was a prospective clinical study. Twenty-eight patients （42 eyes） with age-related cataract were implanted with ReSTOR MIOLs after phacoemulsification. The 42 eyes were classified as emmetropic， myopic or hyperopic based on axial length. Uncorrected and best corrected visual acuity for far， intermediate （with high and low contrast sensitivity） and near vision were compared at 6 months after surgery. The predictability of 3 different formula calculations were evaluated. Patients were asked to rate photic phenomena， quality of night vision， spectacle independence， and satisfaction with visual outcome by answering a questionnaire. The data were analyzed with an ANOVA and chi-square tests. Results  Uncorrected and best corrected visual acuity for near， intermediate， and far vision were not significantly different among groups， but the intermediate visual acuity， especially low contrast sensitivity， was lower than far and near visual acuity. Postoperative residual refractive errors for the three groups were significantly difference （F=8.33， P＜0.05）. In the myopic group， there was a statisitically significant difference between the actual postoperative refractive error and the predicted refractive error calculated by the Haigis  and Holladay I formulas （P＜0.05）； the actual postoperative refractive error did not differ significantly from the predicted refractive error calculated by the SRK-T formula. Satisfaction with intermediate vision was lower in the hyperopic group than in the others， and the difference was statistically significant （P＜0.05）. The differences in the percentage of time without glasses and adverse visual symptoms such as glare and halo after surgery were not statistically significant among the 3 groups. Conclusion  Preoperative refractive status is a relevant factor influencing the postoperative outcome after implantation of ReSTOR MIOLs.

Objective  To evaluate the safety and efficacy of a 23-gauge transconjunctival sutureless vitrectomy system for the management of traumatic cataract in children and to determine the short-term outcome and complications. Methods  This retrospective study involved a consecutive series of 32 children （32 eyes） who suffered from traumatic cataract from March 2009 to September 2011. Each eye underwent anterior capsulotomy， lentectomy， posterior capsulotomy， and anterior vitrectomy through a superior limbal incision using a 23-gauge vitrectomy cutter. A limbal port incision was used to introduce an infusion micro cannula to maintain the anterior chamber with balance salt solution. The superior limbal incision was enlarged to 2.75 mm by a diamond knife. An intraocular lens （IOL） was implanted in the bag or sulcus. The enlarged incision was closed with one or two 10-0 nylon suture. Refraction correction with spectacles and amblyopic training began 1 week postoperatively. The mean follow-up period was 17.1±8.2 months. Results  All the surgical procedures were successfully performed in all 32 eyes. No intraoperative complication was noted. The mean postoperative intraocular pressure （IOP） was 12.9±2.4 mmHg. Postoperative inflammation was mild. No fibrin reactions， vitreous escape or incarceration were noted in the anterior chamber. Neither significant aqueous flare nor aqueous cell was observed 1 week after surgery. Five eyes （15.6%） had mild posterior synechiae. All eyes had primary IOL implantation. IOL was implanted in the bag in 22 eyes （68.7%） and in the sulcus in 10 eyes （31.3%）. The mean axial length of the 32 eyes was 22.36±1.03 mm at the time of operation and the mean IOL power was +22.97±1.89 D. Four eyes （12.5%） developed visual axis opacification （VAO） and required capsulotomy by YAG laser. IOL pigmentation was noted in 5 eyes （15.6%）. No cases of ocular hypertension， glaucoma， choroidal detachment or retinal detachment were observed. The mean logMAR best corrected visual acuity （BCVA） was 2.37±1.16 preoperatively and 0.39±0.48 at the last follow-up， BCVA was significantly improved （t=10.916， P<0.01）. BCVA was improved in 29 eyes postoperatively. The predictors of good visual outcomes （BCVA≥20/40） included metal as the object causing injury， cataract operation within 3 month after injury and good amblyopic treatment （Fisher=0.028， 0.047， 0.000， respectively. P<0.05）. Conclusion  Management of traumatic cataract in children via an anterior approach using the 23-gauge transconjunctival sutureless vitrectomy system appears safe and effective. Advantages include a more precise capsulotomy and more sufficient lensectomy and anterior vitrectomy， stable intraoperative IOP， and reduced surgical trauma and inflammation.

Objective  To assess phacoemulsification for treatment of a shallow anterior chamber or chronic elevated intraocular pressure caused by lens subluxation after trabeculectomy. Methods  A retrospective analysis was conducted on 7 patients （8 eyes） who underwent phacoemulsification with a capsular tension ring （CTR） and intraocular lens （IOL） implants after trabeculectomy. Lens subluxation was diagnosed by ultrasound biomicroscopy （UBM）. Changes in visual acuity， intraocular pressure （IOP） and anterior chamber depth before and after the operation were compared using a paired samples t test. Results  Phacoemulsification was performed 67.4±34.9 days （30-125 days） after trabeculectomy. Preoperative uncorrected visual acuity （UCVA） （LogMAR） was 0.61±0.36. Postoperative UCVA was 0.16±0.09 at 1 month， which was much better than preoperative UCVA （t=3.629， P<0.01）. Preoperative best corrected visual acuity （BCVA） was 0.38±0.32 （logMAR）. Postoperative BCVA was -0.01±0.10 at 1 month， which was also much better than preoperative BCVA （t=3.898， P<0.01）. Preoperative IOP was 25.45±6.92 mmHg. Postoperative IOP was 15.28±0.76 mmHg at 1 month （t=4.234， P<0.01）. The IOP of all subjects was well controlled without medication. Preoperative central anterior chamber depth was 1.20±0.36 mm. Postoperative central anterior chamber depth was 2.57±0.38 mm at 1 month （t=-11.075， P<0.01）. The extent of lens subluxation was 99.38°±46.02° （90°-180°） found during the operation. Conclusion  A shallow anterior chamber or chronic elevated intraocular pressure caused by lens subluxation can be alleviated by phacoemusification with a CTR and IOL implantation.

Objective  To study the causes of acute high intraocular pressure （HIOP） caused by pupillary block after phacoemulsification with intraocular lens （IOL） implantation and the treatments to manage the condition. Methods  Seventeen patients （17 eyes） with early postoperative acute HIOP caused by pupillary block who underwent cataract phacoemulsification with IOL implantation in Taizhou Eye Hospital between January 2000 and December 2011 were retrospectively analyzed.  Among the 17 cases， 5 cases were caused by onset IOL pupillary capture and 12 cases by capsular block syndrome （CBS）. Conservative approaches were adopted that included tropicamide phenylephrine eye drops for mydriasis and 250 ml of intravenous drip with 20% mannital to the concentrated vitreous for the 5 cases of acute pupillary block HIOP caused by onset IOL pupillary capture. For the other 12 cases with CBS， Nd： YAG laser was used for anterior capsulotomy to cut the margin of the continuous circular capsulorhexis （CCC） in 2 cases and anterior peripheral capsulotomy was performed in 5 cases. Radialization was performed surgically to cut the margin of the CCC in 2 cases and supplied the CCC to enlarge the diameter in 3 cases. And finally， aspiration-irrigation was performed to flush the anterior chamber and the capsule. Intraocular pressure （IOP）， visual acuity， position of IOL， and the conditions of the anterior chamber and capsule were measured after treatment. Results  The patients were followed up for 2-3 months after treatment. Pupillary block disappeared， IOP was normal， visual acuity improved， the anterior chamber deepened and the position of the IOL was normal in all operated eyes. At the last follow-up， IOP was 11-19 mmHg （mean 0.85±0.15 mmHg） and best corrected visual acuity （BCVA） was 0.7-1.0 in 5 cases with IOL pupillary capture. IOP was 12-18 mmHg （mean 15±3.0 mmHg） and BCVA was 0.8-1.0 in 12 cases with CBS. Conclusion  IOL pupillary capture and CBS can that induces acute pupillary block HIOP. Applying mydriasis can effectively resolve acute pupillary block HIOP caused by the IOL pupillary capture. Using ND： YAG laser and operation are the effective measures to treat acute pupillary block HIOP caused by CBS.

Objective To use the Pentacam HR anterior segment analyzer to measure the anterior corneal Q values in different regions of the adult eye and analyze its characteristics with different refractive statuses. Methods A cross-sectional study of 230 adults was conducted. From June 2011 to February 2012， 200 myopic adults and 30 emmetropic adults were selected from the Eye Hospital of Wenzhou Medical College. The myopic patients were grouped by the magnitude of the spherical equivalent （SE） refractive error of the right eye： Emmetropia （30）， low myopia （52）， moderate myopia （58）， high myopia （57） and ultra high myopia （33）. A Pentacam was used to measure the corneal anterior Q values of the nasal， temporal， inferior and superior semi-meridians in 6 mm， 7 mm， 8 mm， and 9 mm diameters， the horizontal and vertical meridian Q values， and the mean Q values in an 8 mm diameter to compare corneal asphericity in different groups. Data were analyzed using ANOVA and paired t test. Results The vertical meridian curvature trend was faster than the horizontal meridian and the difference was statistically significant （t=3.421， P<0.01）. Temporal semi-meridian Q values of the corneal anterior surface were statistically significant for the different groups （F=5.225， P<0.01）. The Q values of the emmetropic group were significantly different from the other groups except for the low myopia group. The difference between the temporal and nasal semi-meridian Q values for the different diameters was statistically significant （F=3.712， 3.488， 2.668， 4.315； P<0.05）. The difference was larger in the emmetropic group than in the other groups and decreased with the degree of myopia. Conclusion There are differences in corneal Q values in different regions and refractive status affects these differences. The differences between individuals will affect the individual peripheral refractive state and ultimately affect the quality of the image on the retina. Customized ablation surgery should therefore take the meridian asymmetry of the cornea into consideration.

Objective  To compare the corneal parameters of the two eyes in a myopia population and to establish the normal range of interocular differences for clinical examination and diagnosis. Methods  In this cross-sectional study， 210 patients （420 eyes） whose mean age was 24.8±0.4 years， average spherical equivalents were -4.96±0.14 D in right eyes and -4.94±0.14 D in left eyes， were measured by Pentacam. Corneal parameters， including mean keratometry Km， central corneal thickness （CCT）， thinnest corneal thickness （TCT）， the location of the thinnest points （X， Y） and the distance from the thinnest to central corneal points （√(x²+y²)） and the interocular differences were recorded. A paired t test was used to assess the differences between the two eyes′ corneal parameters and a Pearson correlation was used to describe their linear relationship. The normal range of interocular differences was described by the 95th percentile or mean＋2 standard deviation （SD）. Results  No statistically significant binocular differences were found in Km （t=-1.38，P>0.05）， CCT （t=1.44， P>0.05）， TCT （t=1.25， P>0.05）， √(x²+y²) （t=1.87， P>0.05） except X （t=-33.92， P<0.01） and Y （t=8.95， P<0.01）. Less than 5% of the sample had differences greater than 0.5 D in Km， 13.67 μm in CCT， 12.83 μm in TCT， 1.52 mm in the vertical location of the thinnest points， 0.32 mm in the horizontal location of the thinnest points， or 0.30 mm in the distance from the thinnest to central corneal points between eyes. Conclusion  Binocular corneal parameters have some differences. The normal range of binocular differences can provide a guide for intraocular lens power calculation， clinical diagnosis and screening of glaucoma and corneal ectasia disease.

Objective  To measure the binocular accommodative amplitude under different monochromatic lights； to evaluate the differences in accommodative amplitude under different monochromatic lights and the correlation between refractive state and accommodative amplitude. Methods  This was a cross-sectional study. Ninety-one subjects （182 eyes）， aged 15~30 years （average 22.9±4.2 years） were enrolled in the study. All subjects underwent refractive examinations measured with MPMVA， amplitude of accommodation measured with a minus lens-stimulated test under white light （440 nm， 560 nm， 610 nm combined light）， red light （610 nm） and green light （560 nm）. A one-way ANOVA and Pearson correlation were used for statistical analysis. Results  ①There were significant differences in the amplitude of accommodation under different lights （F=21.49， P<0.01）： the largest amplitude was under white light （13.04±2.75 D）， green light （12.4±2.61 D） was second， and red light （11.26±2.53 D） was the lowest. ②The amplitude of accommodation under the 3 hights was significantly different （F=21.476， 14.356， 16.540， P<0.01） among emmetropes， low and moderate myopes and high myopes. The smallest amplitude was for emmetropes and the amplitude was for high myopes. The amplitudes of accommodation were not significantly different for emmetropes under different lights （F=1.93， P>0.05） while the other two groups showed significant differences （F=15.684， 11.821， P<0.01）. ③There was a positive correlation between the amplitude of accommodation and refraction （r=0.385， 0.312， 0.328， P<0.01）. ④For each individual， the accommodative amplitude was higher with a higher degree of myopia， under red hight， the differences were not significant （t=-1.803， P<0.05）， under white and green lights， the differences were significant （t=-2.344， 2.474， P<0.05）. Conclusion  The amplitude of accommodation differs when induced by different lights. It is higher with green light than red light， and there was a significant difference in myopes. The amplitude of accommodation is correlated with refractive error； the higher the degree of myopia， the larger the amplitude of accommodation.

Objective  To investigate the physiological function of the isolated rat retina with a multi-electrode array （MEA） system， and develop a more comprehensive method to evaluate retinal function in animals. Methods  In this experimental study， retinas were isolated from 6 Sprague-Dawley （SD） rats， and placed into the recording chamber with the ganglion cell layer facing the biochip electrode array. Retinas were perfused with aerated Ringer′s solution for 15 minutes before recording. Then light-evoked or electrical current-evoked responses of the retinal cells were recorded with an MEA system. The obtained data were analyzed with a Shapiro-Wilk test， and the values were presented as a mean±standard deviation. Results  Typical light-evoked responses were successfully recorded. The amplitude of the field potential became higher as the luminance increased （<256 cd/cm2）. The results also showed that the off-light responses were obtained when the duration of the light stimulus was changed from 6 to 10 seconds. The light-off response was a low amplitude negative wave at the offset of the light stimulus. Moreover， according to the peristimulus time histograms （PSTHs） and raster plots of individual units， the retinal ganglion cells （RGCs） were categorized as either ON， OFF， or ON-OFF. In addition， the responses of RGCs evoked by electrical current usually occurred within 50 ms post stimulus. Conclusion  The MEA can be used to assess the retinal function of animals more comprehensively from different neurons （photoreceptor， bipolar cell and RGC）

Objective  To compare the application and degree of comfort of a new type of dipolar corneal contact lens electrode and the Jet corneal contact lens electrode； to evaluate the potential of this new type of dipolar electrode for multi-focal electroretinograms. Methods  In a comparative study， a new type of dipolar corneal contact lens electrode and the Jet corneal contact lens electrode were applied to the same eye of 15 volunteers （15 eyes） for multi-focal electroretinogram examination. The first order kernel was choosen. Mean response densities， amplitude and latency of P1 in rings 1-5 were recorded. Corneal fluorescein sodium dyeing was assessed after the examination， and the degree of comfort was evaluated with a questionnaire. Data were analyzed using paired t test. Results  P1 response densities and amplitudes in rings 1-5 of the dipolar corneal contact lens electrode were lower than those of the Jet corneal contact lens electrode， but the tendencies of the response densities and amplitudes were almost the same. There was no significant difference in latency between the two kinds of electrodes in rings 2 to 5. Corneal fluorescein sodium dyeing was almost negative with both electrodes. The degree of comfort with the Jet electrodes was better than for the dipolar electrodes， but the difference was not significant. Conclusion  Compared with the Jet electrode， the new type of dipolar electrode can also record correctly， and it is safe and comfortable for the cornea. The dipolar electrodes are more convenient and cheaper than the Jet electrodes， so they cannot only save time but also avoid cross infection.

Objective  To evaluate long-term refractive outcomes of laser in situ keratomileusis （LASIK） for all levels of myopia. Methods  This was a retrospective case series study. One hundred twenty-five eyes of 68 patients who underwent LASIK for myopia and completed over 5 years of follow-up were included in the study. Based on the preoperative spherical equivalent refraction， the eyes were divided into 2 groups. Group A eyes ranged between -0.75 and -6.00 diopters （D） （mild-to-moderate myopia）. Group B eyes ranged between -6.12 and -13.25 D （severe myopia）. Before and at 1 month， 6 months， 1 year and 5 years after the operation， uncorrected visual acuity （UCVA）， best corrected visual acuity （BCVA）， slit-lamp biomicroscopy of the anterior segment，indirect ophthalmoscopy and topography were measured. At the time of the last follow-up， all patients completed a questionnaire assessing their satisfaction with the procedure. Data were analyzed using x² test and paired t test. Results  Uncorrected visual acuity ≥0.5 in groups A and B was obtained in 100% and 96% of eyes， and spherical equivalent refraction within ±1.00 D was obtained in 93% and 84% of eyes at 5 years. Spherical equivalent refraction in groups A and B was -0.021±0.65 D and -0.33±0.80 D， respectively， at five years. The differences compared with 1-year outcomes after the operation were not statistically significant. BCVA was unchanged or improved in 82% of all eyes （103/125）. Overall， only 1 epithelial ingrowth and 1 free partial flap were identified as complications from LASIK. Refraction did not regress in either group between 1 and 5 years. Late-onset complications attributable to LASIK were not observed at the 5-year follow-up， and patient satisfaction with the procedure was high. Conclusion  A long-term follow-up study of patients after undergoing LASIK for myopia shows it is a safe and effective procedure in correcting all levels of myopia. Complications were rare and patient satisfaction with the surgery was high. Refractive stability was maintained over the 5-year period. Late-onset complications attributable to LASIK were not noted.

Objective  To explore the relationship of accommodative convergence/accommodation （AC/A） and accommodative lag， and learn the possible role of heterophoria in the development of the myopia. Methods  It was a cross-sectional study. We selected the juvenile myopes with heterophoria 62 persons（124 eyes） in all， tested their diopter， the degree of horizontal phoria， AC/A and accommodative lag. According to the low， medium and high myopia， we divided them into three groups， and compared the AC/A， accommodative lag of esophoria with exophoria in these three groups and in the meantime， the heterophoria with AC/A and accommodative lag is analyzed. Results  In low myopia group， AC/A and accommodative lag in esophoria is （4.72±0.38）△/D， （0.50±0.20）D respectively， and in exophoria， is （3.45±0.31）△/D， （0.20±0.10）D respectively. In moderate myopia， AC/A and accommodative lag in esophoria is （5.33±0.42）△/D， （0.58±0.08）D respectively， and in exophoria， is （3.26±0.25）△/D， （0.30±0.13）D respectively. In high myopia， AC/A and accommodative lag in esophoria is （4.01±0.38）△/D， （0.50±0.12）D respectively， and in exophoria， is （2.50±0.29）△/D， （0.28±0.12）D respectively； both between AC/A and accommodation lag are statistically significant difference （P<0.05）. The esophoria  degree correlation positively with AC/A （r=0.670， P<0.05） and accommodation lag （r=0.430， P<0.05）. The exophoria degree correlation negatively with AC/A （r=-0.331， P<0.05）， and correlation positively with accommodation lag （r=0.423， P<0.05）. Conclusion  In myopia  patients， AC/A and accommodation lag in esophoria are greater than exophoria， and the esophoria  degree correlation positively both with AC/A and accommodation lag， so we speculate that the patients with esophoria their degree of myopia development more quickly than exophoria， the greater the degree of esophoria， the quicker the degree of myopia developments. The exophoria degree correlation negatively with AC/A， and correlation positively with accommodation lag， so we surmise that the large degree of exophoria plays an important role in the development of myopia through the bigger accommodative lag.

Objective  To evaluate the influence of Ahmed glaucoma valve implantation on the corneal endothelium during a one-year follow-up period. Methods  In a retrospective case study， 21 patients （21 eyes） with refractory glaucoma underwent Ahmed glaucoma valve implantation. The corneal endothelium was assessed by spectral microscopy 1 day preoperatively and 1 week and 1， 3， 6 and 12 months postoperatively. Density and loss ratio of the corneal endothelium cells were assessed and calculated. Intraocular pressure （IOP）， anterior chamber depth （AC） and the position of the drainage tube were also observed. An analysis of variance （ANOVA） was used to compare corneal endothelial cell density at the different time points. Results  The density of corneal endothelium cells decreased after Ahmed glaucoma valve implantation in all 21 eyes. The loss ratio of the corneal endothelium increased over time. Compared to a preoperative value of 2306±229 cells/mm2， the corneal endothelium at 1 week postoperatively was 2299±234 cells/mm2， at 1 month was 2062±234 cells/mm2， at 3 months was 2015±223 cells/mm2， at 6 months was 1999±222 cells/mm2， and at 12 months was 1901±210 cells/mm2 （F=15.3， P<0.01）. The loss ratio of the corneal endothelium were 0.3%， 10.5%， 12.6%， 13.2%， 17.5%. Conclusion  There is a loss in corneal endothelium during the short time period after Ahmed glaucoma valve implantation.

Cell cycle is the most important process for vital alteration. With advanced research on cell cycle and its control mechanism， researchers find that cell cycle control participates in many ocular disease. The study of cell cycle control and ocular diseases not only contributes to a deep understanding of the pathogenesis of ocular disease， but also can provide new methods for preventing and treating some ocular diseases.

The prevalence rate of myopia is rising year by year， so it is critical to identify the risk factors for myopia and then take action to prevent the disease. A large number of researchers propose that the disruption of the circadian photoperiod interferes with normal eye development and results in the occurrence or progression of myopia. This review outlines the correlation between the disruption of the photoperiod and myopia caused by night-time lighting or prolonged daylight （＞12 h） exposure and summarizes relevant animal research as well.