Hydrophobic versus hydrophilic acrylic intraocular lens on posterior capsule opacification: a Meta-analysis

AIM: To conduct a Meta-analysis pooling randomized controlled trials(RCTs) to compare hydrophobic with hydrophilic acrylic intraocular lenses in terms of posterior capsule opacification(PCO) development.METHODS: Electronic databases including PubMed,Embase, and the Cochrane Library were queried from their starting till January 2020. RCTs investigating the impact of hydrophobic versus hydrophilic acrylic intraocular lenses on PCO were considered eligible in this study. The pooled effect estimates were calculated using the random-effects model.RESULTS: Thirteen RCTs comprising of 939 patients(1263 eyes) were covered in this study. Patients with hydrophobic acrylic intraocular lenses had a lower PCO score than those with a hydrophilic acrylic intraocular lenses [standard mean difference:-1.80;95% confidence interval(CI):-2.62 to-0.98;P<0.001]. Moreover, the frequency of neodymium-doped yttrium aluminum garnet(Nd:YAG)capsulotomy in patients with hydrophobic acrylic intraocular lenses was significantly lower than patients with hydrophilic acrylic intraocular lenses(relative risk: 0.38;95%CI: 0.20-0.71;P=0.003).CONCLUSION: These findings suggest that hydrophobic acrylic intraocular lenses are superior to hydrophilic acrylic intraocular lenses in patients after cataract surgery due to lower PCO score and reduced Nd:YAG capsulotomy. While similar studies are conducted by other researchers, the present study conducted subgroup analyses that show superior results with hydrophobic lenses in trials conducted in western countries.

Posterior segment nucleotomy for dislocated sclerotic cataractous lens using chandelier endoilluminator and sharp tipped chopper

· AIM: To describe a new surgical technique for managing dislocated sclerotic cataractous lens.· METHODS: Six patients with advanced posteriorly dislocated cataracts were operated at a tertiary care centre and analyzed retrospectively. After standard 3 port23 G pars plana vitrectomy and perfluorocarbon liquid(PFCL) injection, the dislocated white cataract was held with occlusion using phaco fragmatome and then chopped into smaller pieces with a sharp tipped chopper using 25 G chandelier endoilluminator. Each piece was emulsified individually. Following aspiration of PFCL,Fluid Air Exchange was done in all the cases and surgery completed uneventfully.·RESULTS: Best corrected visual acuity(BCVA) in all the patients was better than 6/12 after one month of follow up. No serious complications were noted till minimum 6mo of follow up.·CONCLUSION: Four port posterior segment nucleotomy with a chandelier endoilluminator, fragmatome and a chopper appears to be a safe, easy and effective procedure for managing dislocated sclerotic cataractous nuclei. Ultrasonic energy used and adverse thermal effects of the fragmatome on the sclera may be lesser.

A new technique for Nd:YAG laser posterior capsulotomy

AIM:To investigate the effects of a new opening pattern in neodymium:yttrium-aluminum-garnet(Nd:YAG)laser posterior capsulotomy on visual function.METHODS:This technique was conducted along a circular pattern.The energy ranged between 0.8 and1.2 mJ/pulse was consumed and mean total energy levels were 74±21 mJ(mean±standard deviation:SD,from 40 to167)and laser shots aimed at 150μm away behind a datum point and went along an imaginary line which extends 0.5 mm inside from optic margin and into the circular en bloc pattern.Vitreous stands were attached with fragment and then they were cut off by the laser after circular application.The circular fragment was completely separated from vitreous,and then this fragment was quickly sunk in intravitreal space.RESULTS:The follow-up period ranges from at least a week to 40mo,making 15.8mo on average.The procedural outcome showed 96%(74 eyes out of the 77eyes)enhancement in patients’visual acuity.Cystoid macular edema or retinal detachment was not observed in any of the patients during follow-up periods.CONCLUSION:This new technique is expected to improve the weaknesses that the conventional procedures have by adding the process to cut off vitreous stands attached with the fragment by the laser to the circular application.

Effect of four different intraocular lenses on posterior capsule opacification

AIM: To evaluate the impact of 4 different intraocular lenses(IOLs) on posterior capsule opacification(PCO) by comparing the neodymium: yttrium-aluminum-garnet(Nd:YAG) laser capsulotomy rates.METHODS: This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies.· RESULTS: An Nd:YAG laser posterior capsulotomy was performed in 153(3.07%) of the 4970 eyes. The mean follow-up time was 84 mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1-and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared.· CONCLUSION: In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design(1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate.

Intraocular lens implantation performed first to protect the posterior capsule in Morgagnian cataracts during phacoemulsification

This study evaluated the safety of a modified method to implant an intraocular lens (IOL) into the capsular bag immediately after capsulorhexis with a whole or partial nucleus to protect the posterior capsule (PC) during phacoemulsification in a series of 12 Morgagnian cataracts. For 3 cases of hypermature cataracts with smaller and rigid nuclei, after a complete capsulorhexis, an IOL was directly inserted into the capsular bag, which protected the PC during the subsequent phacoemulsification process in the iris plate. For the other 9 cases with larger and softer nuclei, after the nucleus was partially emulsified, the IOL was inserted into the bag. Even with an obvious surge for some cases, the surgeries were uneventful in all 12 cases, with no PC rent or vitreous loss. IOL implantation into the capsular bag with a whole or partial nucleus can provide effective protection for the PC for hypermature cataract during phacoemulsification.

Corneal astigmatism correction with scleral flaps in trans-scleral suture-fixed posterior chamber lens implantation:a preliminary clinical observation

AIM: To study the impact of scleral flap position, under which the posterior chamber intraocular lenses (PC-IOL) were sulcus-fixed by trans-scleral suture, on cornea astigmatism. METHODS: Twenty-six aphakic or cataract eyes were comprised in this prospective noncomparative case series study. Eleven eyes had traumatic cataract removed without sufficient capsular support, 3 had blunt trauma with subluxated traumatic cataract, 8 had undergone vitreoretinal surgery and 4 had congenital cataract removed. The average age was 54 years (range 21-74 years), with 17 men and 7 women. The foldable PC-IOL was fixed in sulcus by trans-scleral suture. The incision for IOL implantation was made 1mm posterior to limbus along the steepest meridian of cornea, while scleral flaps to bury the knots of trans-scleral suture were made along the flattest meridian. All the surgeries were performed by a single doctor (Ma L), and the follow up was at least 13 months (range 13-28 months). The preoperative, 3 months and 1 year postoperative corneal curvature along the steepest and flattest cornea meridian and overall cornea astigmatism were compared. RESULTS: The curvature along the steepest meridian changed from 44.25 +/- 2.22D preoperatively to 44.08 +/- 2.16D at 3 months postoperatively, and 43.65 +/- 5.23D at 1 year postoperatively (P>0.05); the curvature along the flattest meridian changed from 41.24 +/- 2.21D preoperatively to 43.15 +/- 3.94D at 3 months postoperatively, and 42.85 +/- 5.17D at 1 year postoperatively (P<0.05); and the surgery induced astigmatism (SIA) on cornea was calculated by vector analysis, which was 2.42 +/- 2.13D at 3 months postoperatively, and 2.18 +/- 3.42D at 1 year postoperatively, the difference was statistically significant (P<0.05). CONCLUSION: The scleral flap made along the flattest meridian, under which the posterior chamber intraocular lenses (PCIOL) were sulcus-fixed by trans-scleral suture, can steepen the cornea in varying degrees, thus reducing preexisting corneal astigmatism.

Comparison of posterior capsule opacification at 360-degree square edge hydrophilic and sharp edge hydrophobic acrylic intraocular lens in diabetic patients

·AIM: To compare posterior capsule opacification(PCO)degree and visual functions after phacoemulsification in eyes implanted with 360-degree square edge hydrophilic acrylic intraocular lens(IOL)(570C C-flex, Rayner) and sharp edge hydrophobic acrylic IOL(Sensar AR40 e,AMO) in diabetic patients.· METHODS: Sixty diabetic patients underwent uneventful phacoemulsification and randomly implanted one of the two IOLs. The PCO value was measured by retroillumination photographs and Evaluation of Posterior Capsule Opacification(EPCO) 2000 image-analysis software at 1, 6, 12, and 24 mo after surgery. Visual acuity, and contrast sensitivity in photopic and mesopic conditions were also examined at each follow up time point. The incidence of eye that required Nd:YAG laser posterior capsulotomy were also compared.·RESULTS: There was not any statistically significant difference in PCO scores between Rayner C-flex 570 C group and Sensar AR40 e group at each follow up time point. Visual acuity, Nd:YAG capsulotomy incidence and contrast sensitivity also had no significant difference during the 24 mo follow-up.·CONCLUSION: For diabetic patients, Rayner 570 C Cflex and Sensar AR40 e IOLs are same effective for prevent PCO. The 360-degree square edge design maybe is a good alternative technique to improve PCO prevention.

Comparison of two Nd:YAG laser posterior capsulotomy: cruciate pattern vs circular pattern with vitreous strand cutting

AIM： To investigate the effects and safety of neodymium： yttrium-aluminium-garnet（Nd：YAG） laser posterior capsulotomy with vitreous strand cuttingMETHODS： A total of 40 eyes of 37 patients with symptomatic posterior capsular opacity（PCO） were included in this prospective randomized study and were randomly subjected to either cruciate pattern or round pattern Nd：YAG posterior capsulotomy with vitreous strand cutting（modified round pattern）. The best corrected visual acuity（BCVA）, intraocular pressure（IOP）, refractive error, endothelial cell count（ECC）, anterior segment parameters, including anterior chamber depth（ACD） and anterior chamber angle（ACA） were measured before and 1 mo after the laser posterior capsulotomy. RESULTS： In both groups, the BCVA improved significantly（P〈0.001 for the modified round pattern group, P=0.001 for the cruciate pattern group）; the IOP and ECC did not significantly change. The ACD significantly decreased（P〈0.001 for both） and the ACA significantly increased（P=0.001 for the modified round pattern group and P=0.034 for the cruciate group）. The extent of changes in these parameters was not significantly different between the groups.CONCLUSION： Modified round pattern Nd：YAG laser posterior capsulotomy is an effective and safe method for the treatment of PCO. This method significantly changes the ACD and ACA, but the change in refraction is not significant. Modified round pattern Nd：YAG laser posterior capsulotomy can be considered a good alternative procedure in patients with symptomatic PCO.

Surgical stress and cytoskeletal changes in lens epithelial cells following manual and femtosecond laser-assisted capsulotomy

AIM:To study the effect of mechanical stress on the cytoskeleton in lens epithelial cells following conventional phacoemulsification surgery(CPS)and femtosecond laserassisted cataract surgery(FLACS).METHODS:The cytoskeleton of the epithelial cells of the anterior lens capsules(ALC)removed by CPS and FLACS was examined by immunohistochemistry.Expression of the intermediate filament,glial fibrillary acidic protein(GFAP),and glutamine synthetase(GS)immunoreactivity were detected.In order to map the actin network of cells,fluorescently labeled phalloidin was used.The samples were examined using confocal laser scanning microscopy.RESULTS:GFAP expression was visible in a larger number of the epithelial cells after CPS compared to FLACS.In CPS sample’s epithelial cells,GFAP immunoreactivity indicated robust morphological change.Regarding the actin filaments,the presence of tubular elements connecting epithelial cells,regular actin pattern and marked cortical network after CPS were found.Following FLACS,the actin cytoskeleton of the epithelial cells remained densely structured,and the tubular elements were undetectable,however,the above-mentioned regular actin pattern and the marked cortical network were visible.CONCLUSION:The conventional removal of the ALC induces more robust changes of the cytoskeleton of the lens epithelial cells.

A Clinical Analysis of 120 Cases with Traumatic Cataract Treated by Extracapsular Cataract Extraction and Posterior Chamber Intraocular Lens Implantation

Extracapsular cataract extraction was performed combined with posterior chamber intraocular lens implantation on 120 inpatients (122 eyes) with traumatic cataract from 1992 to 1997. The results revealed that this combined operation can make most of them get useful visual acuity, although they were often accompanied with several comlicated eye injuries. We think the most important thing is to choose suitable opertion time, the reasonable operation method and take close followup after operation.

New Management of Malignant Glaucoma by Phacoemulsification with Posterior Chamber Foldable Intraocular Lens Implantation

Objective:To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma. Patients and Methods:Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study.12 patients developed malignant glaucoma after filtration surgery.1 developed after peripheral iridectomy.1 patient developed malignant glaucoma without any clear cause.Cataract phacoemulsification was performed.Posterior chamber intraocular foldable lens was implanted in 10 cases of patients.Results:All 14 patients were cured wiht normal intraocular pressure,normal anterior chamber depth and increased visual acuity.Conclusion:Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

New Management of Angle-closure Glaucoma by Phacoemulsification with Foldable Posterior Chamber Intraocular Lens Implantation

Objective:To investigate the management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens(PC-IOL)implantation.Design:Retrospective,noncontrolled interventional case series.Participants:In36eyes with angle-closure glaucoma(ACG),there were18eyes with primary acute angle-closure glaucoma(PACG),14eyes with primary chronic angle-closure glaucoma(PCCG),3eyes with secondary acute angle-closure glaucoma(SACG)and 1eye with secondary chronic angle-closure glaucoma(SCCG).Intervention:Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures:Postoperative visual acuity,IOP,axial anterior chamber depth.Results:After a mean postoperative follow-up time of 8.81±7.45months,intraocular pressure was reduced from a preoperative mean of 23.81±17.84mmHg to a postoperative mean of 12.54±4.73mmHg(P=0.001).Mean anterior hamber depth was1.75±0.48mm preoperatively and2.29±0.38mm postoperatively(P=0.000).Best spectacle-corrected visual acuith in 36eyes ranged from0.01to0.7(20/200to20/30)postoperatively,which was better than preoperative VA ranging from hand movement to 0.4(20/50)(P=0.000).Conclusion:Phacoemulsification with posterior chamber foldable intraocular lens implantation can be a good alternative in treating angle-closure glaucoma,Eye Science 2000;16:22-28.

Clinical prediction of insufficient vaults after implantable collamer lens implantation

AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(<250μm)after implantable collamer lens(ICL V4c;STAAR Surgical)implantation.METHODS:The participants underwent ICL surgery and were divided into the low(<250μm)and normal(250-1000μm)vault groups based on the postoperative vault at 3mo.The preoperative biometric parameters and clinical outcomes were compared between the two groups.The relationship between the 3-month vault values and preoperative ocular parameters were evaluated by Generalized estimating equations.RESULTS:Sixteen(23 eyes)and 36 patients(63 eyes)were in the low and normal vault groups,respectively.All implantation procedures were uneventful with no cataract formation in the early postoperative period.The sulcusto-sulcus lens rise(STSL)and iris ciliary angle(ICA)were correlated with vault at 3mo after surgery.Every 0.1 mm increase in STSL was associated with 38.9μm decrease in the postoperative 3-month vault.A rise of 1 degree in ICA is associated with a reduction of 4μm in vault.CONCLUSION:Eyes with a narrow ciliary sulcus are associated with a higher rate of low vault after ICL implantation,suggesting a need for adjustments to the ICL size in these patients.Evaluating the characteristics of the ciliary sulcus contributes valuable information to predict low vault after surgery.

Overexpression of TRPV1 activates autophagy in human lens epithelial cells under hyperosmotic stress through Ca^(2+)-dependent AMPK/mTOR pathway

●AIM:To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells(LECs)under hyperosmotic stress.●METHODS:LECs were treated with hyperosmotic stress at the concentration of 270,300,400,500,or 600 mOsm for 6,12,18,24h in vitro.Polymerase chain reaction(PCR)was employed for the mRNA expression of autophagyrelated genes,while Western blotting detected the targeted protein expression.The transfection of stub-RFP-sens-GFPLC3 autophagy-related double fluorescence lentivirus was conducted to detect the level of autophagy flux.Scanning electron microscopy was used to detect the existence of autolysosome.Short interfering RNA of autophagy-related gene(ATG)7,transient receptor potential vanilloid(TRPV)1 overexpression plasmid,related agonists and inhibitors were employed to their influence on autophagy related pathway.Flow cytometry was employed to test the apoptosis and intracellular Ca^(2+)level.Mitochondrial membrane potential was measured by JC-1 staining.The cell counting kit-8 assay was used to calculate the cellular viability.The wound healing assay was used to evaluate the wound closure rate.GraphPad 6.0 software was utilized to evaluate the data.●RESULTS:The hyperosmotic stress activated autophagy in a pressure-and time-dependent manner in LECs.Beclin 1 protein expression and conversion of LC3B II to LC3B I increased,whereas sequestosome-1(SQSTM1)protein expression decreased.Transient Ca^(2+)influx was stimulated caused by hyperosmotic stress,levels of mammalian target of rapamycin(mTOR)phosphorylation decreased,and the level of AMP-activated protein kinase(AMPK)phosphorylation increased in the early stage.Based on this evidence,autophagy activation through the Ca^(2+)-dependent AMPK/mTOR pathway might represent an adaptation process in LECs under hyperosmotic stress.Hyperosmotic stress decreased cellular viability and accelerated apoptosis in LECs and cellular migration decreased.Inhibition of autophagy by ATG7 knockdown had similar results.TRPV1 overexpression increased autophagy and might be crucial in the occurrence of autophagy promoted by hyperosmotic stress.●CONCLUSION:A combination of hyperosmotic stress and autophagy inhibition may be a promising approach to decrease the number of LECs in the capsular bag and pave the way for improving prevention of posterior capsular opacification and capsular fibrosis.

Membrane Formation on the Surface of Implanted Posterior Chamber Intraocular Lenses

Purpose:To study the prevention and treatment of the membrane formation on the lens surface after extracapsular cataract extraction(ECCE)with posterior chamber intraocular lens(PCIOL)implantation.Methods:We reviewed the records of 312 cataractous patients that had undergone ECCEwith PCIOLimplantation between1989and1993,Postoperatively all pa-tients were examined under slit-lamp microscopy.The membrane formation on the surface of PCIOLin pupilar area was divided into four grades.Two mem-branes of surgical removal were observed under a transmission electrom mi-croscopy.One PCIOLof surgical removal was observed under a scanning electron microscopy.Results;Of312 patients,21 had the membrane formation on the surface of the PCIOL postoperatively.The incidence of the membrane formation was6.7%.Comparisone with cases of senile cataract showed the incidence to be significantly the highest among;1.patients who had traumatic cataract(P<0.05);2.pa-tients with complicated cataract(P<0.05).Interoperatively residual lens corten and rupture of posterior capsule,interval time betwwen the first and second eye operations less than 1month are the main factors of menbrane formation.The ultrastructure in membrane and cytology on the lens surface showed that the membrane on the surface of PCIOLs is usually composed of acellular protein film and cellular elements,including macrophages.fibroblast-like cells,epithelioid cells,giant cells,fibroblasts and collagen fibrils,etc.Conclusions:The cellular response on the surface of an implanted PCIOLis a chonic foreign-body inflammatory reaction and the membrane of the surfaceof implanted PCIOL is a reactive membrane of the foreign-body.Eye Science1995;11:131-135.

Effect of Liposome-Encapsulated Total Alkaloid of Harmaline on Rabbit Lens Epithelial Cells:Experimental Study on the Prevention of Posterior Capsule Opacification

Purpose: To investigate whether liposome encapsulated total alkaloid of Harmaline (TAH) as a therapeutic agent is beneficial to prevention of posterior capsular opacifi-cation (PCO).Methods: Liposome-encapsulated TAH was prepared by modified freeze-thawing method. 0. 1ml of liposome-encapsulated TAH (0. 2mg/ml) was injected into the capsular bag during extracapsular lens extraction (ECLE) of each eye in total 10 rabbit eyes. Blank liposome or balance salt solution (BSS) was used as control. Slit-lamp examination and histopathological examination was used to evaluated capsule opacifica-tion. Intraocular pressure (IOP) , density and morphology of corneal endothelia cells, the amplitude and latency of b wave of ERG were measured.Results: The inflammatory response was mild both in TAH treated and the control group. PCO formation occurred in the control group 2 weeks postoperatively, but the posterior capsule was clear in TAH treated eyes. 4 weeks and 8 weeks after operation, PCO occurred both in TAH

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

Purpose:To investigate the influence of posterior corneal astigmatism on the prediction accuracy of toric multi­focal intraocular lens(IOL)calculation.Methods:The keratometric astigmatism measured by Lenstar LS 900(KCA_(L)),keratometric astigmatism(KCAp)and total corneal astigmatism(TCA)measured by Scheimpflug camera(Pentacam HR)were documented and analyzed accordingly.Three deduction models using different parameters were compared.Model 1:KCA_(L)+keratometric comeal surgically induced astigmatism(KCSIA,0.30 D@50°);Model 2:KCA_(P)+KCSIA);Model 3:TCA 4-total CSIA(TCSIA,0.23 D@50°).The prediction errors of each model as the difference vector between the actual and the intended residual astigmatism were compared.Results:Seventy-six eyes implanted with toric multifocal IOLs were included in this study.The vector differences of the actual KCSIA and TCSIA were statistically significant in the total sample and against-the-rule(ATR)sub­group(both P<0.05).Model 1 deduced the smallest mean values of prediction error,while that of Model 3 were smaller than that of Model 2,both in the total sample and the ATR subgroups(all P<0.05).Meanwhile,in the total sample and ATR subgroups,the centroid vector magnitudes of Model 3 were smaller than that of Model 1(0.31±0.76 D and 0.39±0.76 D).Conclusions:The calculation of toric multifocal IOL should be individualized especially in the ATR eyes for the impact of PCA on the estimation of the preoperative comeal astigmatism and the CSIA.

Combined pars plana vitrectomy and suture less scleral fixation of foldable intraocular lens:single surgery visual rehabilitation of dislocated lens/intraocular lens

Background:To evaluate efficacy and safety of combined pars plana vitrectomy(PPV)and scleral fixated intraocular lens(SFIOL)surgery as a single procedure.Methods:Retrospective interventional case series done at a tertiary eye care center in Northern India.Eleven patients who underwent combined PPV and SFIOL surgery were included and analyzed retrospectively.Results:Mean age of the patients was 43.36±15.12 years(range,22-64 years).Eight were male.Mean baseline best corrected visual acuity(BCVA)was 0.78±0.63 logMAR units while the mean post-operative BCVA at 6 months follow-up was 0.37±0.29 logMAR units,the visual gain being statistically significant(P=0.021).None of the patients had a drop in BCVA with nine patients having final BCVA better than 0.48 logMAR units.Choroidal detachment(CD)was the only notable complication,seen in three patients.Other complications included two cases of intraoperative retinal breaks,a case each of reversible corneal edema,ocular hypertension and cystoid macular edema.Conclusions:Combined PPV and SFIOL is an efficacious procedure for managing IOL/lens dislocation and aphakia in a single surgery.There may be short-term reversible complications with no impact on final visual gain.

Early results of circularity and centration of capsulotomy prepared by three different methods

AIM:To compare the difference of capsulotomy produced by precision pulse capsulotomy(PPC),manual(M-CCC),and femtosecond laser assisted capsulotomy(FLAC)in relation to intraocular lens(IOL)centration,circularity and its effect on visual outcomes.METHODS:Prospective,non-randomized comparative study conducted at LV Prasad Eye Institute,Hyderabad,India.Sixty eyes of 52 patients were grouped into 3(FLAC,PPC and M-CCC)based on capsulotomy techniques used.Twenty consecutive eyes with uneventful phacoemulsification and with no comorbidities affecting the capsulotomy or visual outcome were included in each group.The main outcome measure was IOL centration in relation to capsulotomy and pupil.Secondary outcome measures were post-operative visual acuity,manifest refraction and aberration profile between groups.RESULTS:At 5 wk the visual,refractive outcomes and endothelial cell density were comparable between the 3 groups.The median circularity index of FLAC was statistically significantly different to M-CCC or PPC(1-10)groups(P<0.01)but PPC(11-20)was comparable to FLAC.Decentration of IOL center in relation to capsulotomy was seen only between the PPC(1-10)group and FLAC group(P=0.02).The IOL was well centered in relation to the pupil in all the groups(P=0.46).The quality of vision parameters like the higher order aberrations,spherical aberration,coma,trefoil,modular transfer function,and Strehl ratio were comparable between the groups.CONCLUSION:Our study shows that despite differences in the morphology of capsulotomy produced by PPC,M-CCC,FLAC a well-centered IOL can be achieved.The measured capsular morphology parameters do not affect visual outcomes.

Changes in crystalline lens parameters during accommodation evaluated using swept source anterior segment optical coherence tomography

Backgrounds:To assess changes in anterior segment biometry during accommodation using a swept source anterior segment optical coherence tomography(SS-OCT).Methods:One hundred-forty participants were consecutively recruited in the current study.Each participant underwent SS-OCT scanning at 0 and−3 diopter(D)accommodative stress after refractive compensation,and ocular parameters including anterior chamber depth(ACD),anterior and posterior lens curvature,lens thickness(LT)and lens diameter were recorded.Anterior segment length(ASL)was defined as ACD plus LT.Lens central point(LCP)was defined as ACD plus half of the LT.The accommodative response was calculated as changes in total optical power during accommodation.Results:Compared to non-accommodative status,ACD(2.952±0.402 vs.2.904±0.382 mm,P<0.001),anterior(10.771±1.801 vs.10.086±1.571 mm,P<0.001)and posterior lens curvature(5.894±0.435 vs.5.767±0.420 mm,P<0.001),lens diameter(9.829±0.338 vs.9.695±0.358 mm,P<0.001)and LCP(4.925±0.274 vs.4.900±0.259 mm,P=0.010)tended to decreased and LT thickened(9.829±0.338 vs.9.695±0.358 mm,P<0.001),while ASL(6.903±0.279 vs.6.898±0.268 mm,P=0.568)did not change significantly during accommodation.Younger age(β=0.029,95%CI:0.020 to 0.038,P<0.001)and larger anterior lens curvature(β=−0.071,95%CI:−0.138 to−0.003,P=0.040)were associated with accommodation induced greater steeping amplitude of anterior lens curvature.The optical eye power at 0 and−3 D accommodative stress was 62.486±2.284 and 63.274±2.290 D,respectively(P<0.001).Age was an independent factor of accommodative response(β=−0.027,95%CI:−0.038 to−0.016,P<0.001).Conclusions:During−3 D accommodative stress,the anterior and posterior lens curvature steepened,followed by thickened LT,fronted LCP and shallowed ACD.The accommodative response of−3 D stimulus is age-dependent.