Identification of Small Molecules for Prevention of Lens Epithelium-Derived Cataract Using Zebrafish

Cataract is the leading cause of blindness worldwide. It can be treated by surgery, whereby the damaged crystalline lens is replaced by a synthetic lens. Although cataract surgery is highly effective, a relatively common complication named posterior capsular opacification (PCO) leads to secondary loss of vision. PCO is caused by abnormal proliferation and migration of residual lens epithelial cells (LECs) that were not removed during the surgery, which results in interruption to the passage of light. Despite technical improvements to the surgery, this complication has not been eradicated. Efforts are being made to identify drugs that can be applied post-surgery, to inhibit PCO development. Towards the goal of identifying such drugs, we used zebrafish embryos homozygous for a mutation in plod3 that develop a lens phenotype with characteristics of PCO. Using both biased and unbiased approaches, we identified small molecules that can block the lens phenotype of the mutants. Our findings confirm the relevance of zebrafish plod3 mutants' lens phenotype as a model for lens epithelium-derived cataract and add to our understanding of the molecular mechanisms that contribute to the development of this pathology. This understanding should help in the development of strategies for PCO prevention.

Posterior capsular opacification and Nd:YAG capsulotomy rates in patients implanted with square-edged and non-square-edged intraocular lenses in manual small-incision cataract surgery: A randomized controlled study

Purpose

To study posterior capsular opacification (PCO) and neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomy rates in patients implanted with square-edged and non-square-edged intraocular lenses (IOLs) in manual small-incision cataract surgery (MSICS).

Setting

Tertiary eye care center.

Design

Prospective, comparative, and randomized controlled study.

Methods

This study included patients with senile cataracts scheduled for MSICS and IOL implantation. One eye of each patient was randomized to the implantation of square-edged (S group) or non-square-edged IOL (NSQ group). An independent observer analyzed PCO at 6, 12, 18, and 24 months under slit-lamp illumination.

Results

A total of 104 eyes were included in this study. The mean age of the participants in the two groups was 63.2 (±8.2) years, and there were 65 (62.5%) men and 39 women (37.5%). The mean best-corrected visual acuity (BCVA) values at 6, 12, and 18 months were 0.157 (±0.10), 0.11 (±0.12), and 0.12 (±0.11), respectively, in the S group and 0.17 (±0.10), 0.17 (±0.12), and 0.20 (±0.17), respectively, in the NSQ group. At 12 (P = 0.03) and 18 months (P = 0.01) follow-up, the BCVA of the S group was significantly better than that of the NSQ group. Four eyes in the NSQ group and one eye in the S group required Nd:YAG.

Conclusion

Evaluation of PCO and Nd:YAG capsulotomy rates showed that the 360° square of the posterior IOL edge plays a role in the prevention of PCO. Owing to the low cost of the material and the easy availability of IOLs manufactured from it, square-edged IOL has a definite role in the prevention of PCO in MSICS.

Bilateral limbal stem cell deficiency with xeroderma pigmentosum in a young Asian child

Key Clinical Message

Xeroderma pigmentosum is an autosomal recessive disorder with various ocular manifestations of which bilateral limbal stem cell deficiency is a rare manifestation. Timely diagnosis and meticulous management are vital in these cases to prevent irreversible ocular sequelae.

Abstract

Bilateral limbal stem cell deficiency (LSCD) can be a rare manifestation in patients afflicted with xeroderma pigmentosum (XP). The authors report a rare case of a 12-year-old boy who presented with redness and defective vision and was diagnosed with bilateral LSCD and hyperpigmented lesion over the face and trunk suggestive of XP.

HNF4A negatively regulated posterior capsular opacification via transcriptional inhibition of MMP2

Purpose: Posterior capsular opacification (PCO) is the most common complication after cataract surgery. Abnormal proliferation, migration, epithelial-mesenchymal transition (EMT), and extracellular matrix (ECM) synthesis of residual lens epithelial cells (LECs) cause matrix contraction and capsule shrinkage, which are considered to be the main pathogenic mechanisms of PCO. Hepatocyte nuclear factor 4α (HNF4A) has been reported to regulate EMT in different tumours. Our objective was to investigate the role and mechanism of HNF4A in PCO.Methods: HNF4A expression was tested in PCO rat lens capsules and cell models. HNF4A was knocked down using small hairpin RNA. Knockdown and overexpression of HNF4A were achieved by lentivirus in HLE-B3 cells. Cell viability was measured by Cell Counting Kit-8 assay. Cell migration ability was evaluated by wound healing and Transwell assays. EMT markers were detected by Western blotting. Transcriptome sequencing was used to screen for downstream effectors of HNF4A. Chromatin immunoprecipitation-qPCR and a dual luciferase reporter assay were used to determine the binding of HNF4A to the MMP2 promoter region.Results: HNF4A was downregulated in PCO tissue and cell models. In vitro studies showed that HNF4A deletion facilitated cell proliferation, migration, and EMT protein marker expression in LECs. HNF4A knockdown promoted EMT and migration of LECs via MMP2. Mechanistically, HNF4A decreased MMP2 expression by binding to the MMP2 promoter region. HNF4A deletion also promoted EMT in rat lens capsules.Conclusions: We demonstrated that HNF4A inhibited EMT of LECs by directly binding to the MMP2 promoter region and inhibiting the expression of MMP2, thus leading to retardation of PCO formation and development, suggesting that HNF4A is a potential therapeutic target for PCO.

The complication rate following Neodymium-doped Yttrium Aluminum Garnet laser posterior capsulotomy for posterior capsular opacification in patients with and without comorbidities

Purpose

To study the complication rate following Nd: YAG posterior capsulotomy posterior capsular opacification (PCO) in patients with and without comorbid conditions.

Methods

This was a prospective, interventional, comparative, and observational study. A total of 80 eyes, consisting of 40 eyes without ocular comorbidities (group A) and 40 eyes with ocular comorbidities (group B) that were being treated with Nd: YAG capsulotomy for PCO, were included. Visual outcome and complications of Nd: YAG capsulotomy were studied.

Results

The mean age of group A patients was 61.65 ± 8.85 years and that of group B patients was 63 ± 10.46 years. Of the total, 38 (47.5%) were men and 42 (52.5%) were women. In group B, the ocular comorbidities were moderate nonproliferative diabetic retinopathy (NPDR) (n = 14 eyes; 14/40 = 35%), subluxated intraocular lens (IOL; <2 clock hours of subluxation; n = 6), age-related macular degeneration (ARMD; n = 6), post-uveitic eyes (having old signs of uveitis, no episode of uveitis since the last 1 year; n = 5), and operated cases of traumatic cataract (n = 4). The mean energy required in groups A and B was 46.95 ± 25.92 and 42.62 ± 21.85 mJ, respectively (P = 0.422). The average energy requirement in Grade 2, Grade 3, and Grade 4 PCO was 22.30, 41.62, and 79.52 mJ, respectively. An increase in intraocular pressure (IOP) of >5 mmHg from pre-YAG levels was observed in one patient in each group on day 1 postprocedure, for which medical treatment was given to both patients for 7 days. One patient in each group had IOL pitting. No patient had any other complications attributable to ND:YAG capsulotomy.

Conclusion

Nd:YAG laser posterior capsulotomy is a safe procedure for PCO in patients with comorbidities. Visual outcomes were excellent after Nd:YAG posterior capsulotomy. Although a transient increase in IOP was noted, the response to treatment was good and a long-term increase in IOP was not observed.

Refractive Changes After Nd:YAG Capsulotomy in Pseudophakic Eyes

Purpose

To analyze refractive changes after neodymium: yttrium-aluminum-garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

Patients and Methods

Patients who underwent Nd:YAG capsulotomy after cataract surgery from January 2013 to April 2022 were included in this retrospective study. Sphere, cylinder, spherical equivalent (SE), axis, and corrected distance visual acuity (CDVA) were compared pre- and postoperatively in 683 eyes of 548 patients at one month (n = 605 eyes) and one year (n = 211 eyes). Patients with both one-month and one-year follow-ups (n = 133) were also compared. Eyes were stratified into single-piece (n = 330), three-piece (n = 30), and light adjustable lenses (LALs) (n = 16). Pre- and postoperative measurements were analyzed within each group.

Results

Cylinder was significantly decreased at one-month (difference: 0.042±0.448 D, p = 0.006) and one-year (difference: 0.101±0.455 D, p = 0.003) compared to preoperative measurements. No significant change in sphere or axis was observed at follow-up visits (p > 0.05). CDVA significantly improved at both time points (p < 0.05). No significant change in any parameters between the one-month and one-year groups was observed (p > 0.05). There was significant improvement in CDVA in the single and three-piece lens groups (p < 0.0001 and p = 0.026, respectively), with no change in the LAL group (p > 0.05).

Conclusion

There were no changes in sphere, axis, or spherical equivalent after Nd:YAG capsulotomy. However, cylindrical error and CDVA were significantly better after the procedure. Lens type did not impact refractive parameters postoperatively.

Twelve-Months Follow-Up Postmarket Study of a Hydrophobic Intraocular Lens Using a Preloaded Automated Injector in an Indian Population

Purpose

To assess real-world clinical outcomes and safety of the Clareon^® intraocular lens (IOL) and AutonoMe^® automated preloaded delivery system in an Indian population.

Patients and methods

This was a prospective, single-arm, multicenter, 12-month clinical study in patients aged ≥20 years with unilateral or bilateral cataracts. Surgery was performed by phacoemulsification followed by implantation of the Clareon monofocal IOL (CNA0T0). Monocular best-corrected distance visual acuity (BCDVA) and uncorrected distance visual acuity (UCDVA) were assessed at 1 week and 1, 6, and 12 months after implantation. Posterior capsular opacification (PCO), surface haze, and glistenings were evaluated at all visits. Surgeons' satisfaction with automated injector system was also evaluated using a questionnaire. Safety was assessed by monitoring adverse events (AEs).

Results

A total of 151 eyes received the CNA0T0 IOL. Mean ± SD monocular BCDVA improved from 0.53±0.44 logMAR preoperatively to 0.00±0.08 logMAR at week 1 and -0.03±0.08 logMAR at 12 months after implantation. At 12 months, 137/137 (100%) of eyes achieved BCDVA of 0.3 logMAR or better. Mean ± SD monocular UCDVA was 0.78±0.40 logMAR preoperatively, 0.11±0.15 logMAR at week 1, and 0.08±0.13 logMAR at 12 months after implantation. At 12 months, 132/137 (96%) eyes achieved UCDVA of 0.3 logMAR or better. Serious intraoperative AEs were posterior capsule rupture (n=1) and ciliary zonular dehiscence (n=1). Surgeons reported that the automated preloaded device was more intuitive compared with other push- or screw-style preloaded injector systems. None of the eyes in this study presented surface haze; all were graded as 0 glistenings at all visits. No clinically significant PCO or neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomies were reported.

Conclusion

The hydrophobic IOL preloaded in an automated injector system provided good visual and refractive outcomes, as well as no surface haze and grade 0 glistenings. None of the patients required Nd:YAG capsulotomy.

Spin-Coating-Based Facile Annular Photodynamic Intraocular Lens Fabrication for Efficient and Safer Posterior Capsular Opacification Prevention

Posterior capsular opacification (PCO) is the most common complication after cataract surgery, which is primarily caused by the proliferation of the residual lens epithelial cells (LECs) in the lens capsule. Previous studies have demonstrated that a drug-eluting intraocular lens (IOL), aimed to in situ eliminate LECs, are an effective and promising way to prevent PCO. However, because of the potential toxicities of the antiproliferative drugs to the adjacent tissues, the safety of such drug-eluting IOLs is still a highly important issue to be solved. In this investigation, a facile photodynamic coating-modified IOL was developed for effective and safer PCO prevention. An annular poly(lactide-co-glycolic acid) (PLGA) coating loaded with photosensitizer chlorin e6 (Ce6) was prepared by a spin-coating technique. The optical property investigations showed that the Ce6@PLGA coating was particularly suitable for the IOL surface modification. The in vitro cell culture investigation showed that Ce6@PLGA coating-modified IOLs effectively eliminated LECs when treated with light illumination, whereas it appeared to have good cytocompatibility without irradiation. The investigation of the cell elimination mechanism showed that the apoptosis of HLECs may be associated with the cytomembrane disruption induced by ROS, which is generated by the photodynamic coating during light illumination. The in vivo implantation experiments confirmed the desired PCO prevention effect, as well as the safety to and biocompatibility with the surrounding tissues. Thus, the facile Ce6@PLGA coating will provide an effective yet safe alternative of IOL surface modification for PCO prevention.

Evaluation of posterior capsular opacification and neodymium-doped yttrium aluminum garnet capsulotomy rates in patients with hydrophilic intraocular lens implantation with and without ocular viscoelastic device

Purpose

To study the effect of intraocular lens (IOL) implantation with and without ocular viscoelastic device (OVD) on posterior capsular opacification (PCO) in eyes with phacoemulsification.

Methods

This prospective, comparative, and randomized case series included 70 patients (140 eyes) with senile cataracts scheduled for phacoemulsification and IOL implantation in a tertiary eye c are center. One eye of each patient was randomized to one of the two groups, namely, control and OVD. After phacoemulsification, the IOL was placed in the capsular bag under balanced salt solution (BSS) in the control group, whereas the IOL was placed under OVD in the OVD group. PCO was analyzed by an independent observer at 6, 12, and 18 months under slit-lamp illumination.

Results

The mean age of the participants in the two groups was 61.2 (±9.9) years. Of the total participants, 68 (48.5%) were men and 72 (51.5%) were women. The mean keratometry (K1, K2) values of the OVD (44.26 ± 1.43, 44.93 ± 1.66) and control (44.51 ± 1.74, 44.69 ± 1.49) groups were similar. The mean IOL powers of the control and OVD groups were 21.25 (±1.94) and 21.53 (±1.86), respectively (P = 0.463). The mean best-corrected visual acuity (BCVA) of the control group at 6-, 12-, and 18-month follow-ups were 0.622 (±0.253), 0.315 (±0.203), and 0.063 (±0.163), respectively, whereas those of the OVD group were 0.592 (±0.253), 0.336 (±0.169), and 0.066 (±0.118), respectively (P = 0.922). None of the patients had postoperative raised intraocular pressure (IOP), uveitis, or endophthalmitis. Three and four eyes in the control and OVD groups, respectively, required neodymium-doped yttrium aluminum garnet (ND: YAG) capsulotomy at study termination (P = 0.999).

Conclusion

The hydroimplantation technique of the placement of hydrophilic IOL did not reduce the PCO rate in the 18-month follow-up period. The ND: YAG capsulotomy rate did not differ between the groups.

Nanoporous Gold Ring-Integrated Photothermal Intraocular Lens for Active Prevention of Posterior Capsular Opacification

Posterior capsular opacification (PCO) is the leading complication after cataract surgery, and is mainly induced by the proliferation and migration of residual lens epithelial cells (LECs). Although numerous attempts have been made to reduce the incidence of PCO, this complication remains a critical challenge in postoperative visual recovery. This study aims to report a functionalized intraocular lens (R-IOL) with a region-confined photothermal effect for the active prevention of PCO after implantation. The outer rim of R-IOL (non-optical area) is decorated with a nanoporous gold (NPG) ring, which can effectively eliminate the LECs around R-IOL, ultimately inhibiting the migration of LECs from the periphery to the visual axis center in the initial stage, and preventing the subsequent PCO. Furthermore, the mechanism of LECs elimination can be attributed to apoptosis induced by mild photothermal therapy. After in vivo implantation for 30 days, PCO is rarely observed in the R-IOL group, whereas the considerably higher incidence of PCO (75%) is found in the pristine IOL (P-IOL) group. The region-confined photothermal effect based on NPG not only provides an active strategy to effectively prevent PCO, but also introduces new opportunities for the treatment of undesirable hyperplasia.

Recent Advances of Intraocular Lens Materials and Surface Modification in Cataract Surgery

Advances in cataract surgery have increased the demand for intraocular lens (IOL) materials. At present, the progress of IOL materials mainly contains further improving biocompatibility, providing better visual quality and adjustable ability, reducing surgical incision, as well as dealing with complications such as posterior capsular opacification (PCO) and ophthalmitis. The purpose of this review is to describe the research progress of relevant IOL materials classified according to different clinical purposes. The innovation of IOL materials is often based on the common IOL materials on the market, such as silicon and acrylate. Special properties and functions are obtained by adding extra polymers or surface modification. Most of these studies have not yet been commercialized, which requires a large number of clinical trials. But they provide valuable thoughts for the optimization of the IOL function.

Corneal Endothelial Changes Following Early Capsulotomy Using Neodymium:Yttrium-Aluminum-Garnet Laser

We aimed to survey whether the timing of neodymium:yttrium–aluminum–garnet (Nd:YAG) laser capsulotomy would alter the corneal endothelial morphology and density. A retrospective cohort study was conducted, and 48 patients with unilateral posterior capsular opacity (PCO) and Nd:YAG laser capsulotomy performance were enrolled. The participants were divided into the early Nd:YAG group (timing ≤ 12 months, n = 20) and late Nd:YAG group (timing > 12 months, n= 28) depending on elapsed months between phacoemulsification and Nd:YAG laser capsulotomy. Endothelial cell density (ECD), coefficient of variant (CV), hexagonality (HEX), and central corneal thickness (CCT) between the two groups were collected. A generalized estimate equation was conducted to evaluate the corneal endothelial parameters between the two groups with an adjusted odds ratio (aOR) and 95% confidence interval (CI). The CDVA was improved after treatment in both groups (both p < 0.001). Chronically, ECD in the early group was significantly decreased one week after treatment (2221.50 ± 327.73/mm² vs. 2441.55 ± 321.80/mm², p < 0.001), which recovered to 2369.95 ± 76.37/mm² four weeks after the treatment but was still lower than the preoperative status (p < 0.001). In addition, the HEX percentage showed a significant reduction at four weeks after treatment (p = 0.028). The ECD in the early group was significantly lower than that in the late group (aOR: 0.167, 95% CI: 0.079–0.356, p = 0.003) in both week 1 (p < 0.001) and week 4 (p = 0.004) after laser treatment. In conclusion, the early application of Nd:YAG laser capsulotomy within one year after cataract surgery may be the reason for postoperative ECD decrement without known etiology.

Circ-MKLN1/miR-377-3p/CTGF Axis Regulates the TGF-β2-induced Posterior Capsular Opacification in SRA01/04 Cells

OBJECTIVE

Posterior capsular opacification (PCO) is a common postoperative ocular complication after cataract surgery. Little research focused on the regulation of circular RNAs (circRNAs) in PCO. This study was designed to investigate the function of circRNA-muskelin (circ-MKLN1) in PCO.

METHODS

SRA01/04 cells were treated with transforming growth factor (TGF)-β2. Cell viability was analyzed by Cell Counting Kit-8 (CCK-8) assay. Transwell assay was used for cell migration and invasion detection. Cell migration was also measured by wound healing assay. Epithelial-mesenchymal transition (EMT)-related proteins and connective tissue growth factor (CTGF) were quantified using western blot.

RESULTS

Cell viability, migration, invasion and EMT process in SRA01/04 cells were facilitated by TGF-β2. Circ-MKLN1 expression was enhanced in 17 PCO lens samples relative to 19 normal lens samples and TGF-β2-treated SRA01/04 cells contrasted to control cells. Downregulation of circ-MKLN1 inhibited the effects of TGF-β2 on SRA01/04 cells. Circ-MKLN1 targeted miR-377-3p and the regulation of si-circ-MKLN1 for the TGF-β2-induced influences was related to the upregulation of miR-377-3p. CTGF was the target gene for miR-377-3p. CTGF knockdown also abolished the TGF-β2-mediated cell growth, migration and invasion of SRA01/04 cells. The function of miR-377-3p was achieved by reducing the CTGF level. TGF-β2-induced CTGF expression promotion was alleviated by si-circ-MKLN1 through upregulating the expression of miR-377-3p.

CONCLUSION

These results showed that circ-MKLN1 contributed to the progression of PCO in vitro by increasing the CTGF expression via sponging miR-377-3p. Circ-MKLN1 might be important for improving the molecular target therapy in PCO.

Nd:YAG Capsulotomy Rates with Two Multifocal Intraocular Lenses

Purpose

To investigate the incidence of Nd:YAG capsulotomy after implantation of two types of multifocal intraocular lenses (MIOLs).

Methods

This retrospective analysis included patients who had undergone cataract extraction and implanted diffractive MIOL (Acri. LISA tri 839M) or asymmetric refractive MIOL (SBL-3) from May 2016 to September 2018. They were followed up for at least 3 years. During the follow-up period, the relevant data of patients were kept by special person in the hospital. The rates of Nd:YAG capsulotomy and the Kaplan-Meier survival curve were used to analyze the two groups.

Results

The Asymmetric Refractive MIOL group was comprised of 98 patients (121 eyes), while the Diffractive MIOL group was comprised of 99 patients (120 eyes). There were no significant differences in age, sex, or IOL power between the two groups. The Nd:YAG rate of the asymmetric refractive MIOL group and the diffractive MIOL group was 3.3% and 7.5% respectively (P = 0.15) in the first year, 14.88% and 22.5% respectively (P = 0.129) in the second year, and 21.49% and 34.17% respectively (P = 0.028) in the third year. In the first 7 months of follow-up, the two groups showed the same performance in the Nd:YAG rate. After that, there was a difference between the two groups, and the difference gradually increased. Until the 27th month of follow-up, the difference was significant (P < 0.05). What is more, there were significant differences in survival (without Nd:YAG capsulotomy)/failure (with Nd:YAG capsulotomy) functions (P = 0.0035).

Conclusion

The incidence of Nd:YAG laser capsulotomy in patients with diffractive MIOLs was higher than that in patients with asymmetric refractive MIOLs.

Effects of Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser Capsulotomy on Visual Outcomes From a Lower-Middle Income Country

Objective

Neodymium-doped yttrium aluminium garnet (Nd: YAG) laser is a non-invasive and effective means to deal with posterior capsule opacification. Although it is safe, it may have some complications. The purpose of this study was to evaluate the efficacy of Nd: YAG laser capsulotomy in terms of visual outcomes.

Methodology

This retrospective study was carried out at the eye department of Shaheed Mohtarma Benazir Bhutto Medical College, Lyari and Sindh Government Lyari General Hospital, Karachi, by using a convenient sampling technique. The duration of the study was six months from 1^st January 2020 to 30^th June 2020. 50 eyes of patients older than 20 years of age of either gender with posterior capsule opacification after cataract surgery for more than 6 months of duration, capsular fibrosis, and visual distortion due to wrinkling were included in the study. 

Results

Our results show that in a total of 50 patients, the mean age was 59.08±5.84 years, of which, 20 (40%) were males. Out of 50 patients, 22 right while 28 left eyes were selected for Nd: YAG laser capsulotomy. None of the patients showed elevated intraocular pressure (IOP) after the 1^st week. Mean IOP was 16.84±3.63 mm of Hg on the 1^st day and mean IOP after 1^st week was 12.48±2.01 mm of Hg. Iritis was observed in 5 (10.0%) patients on the 1^st day and 4 (8.0%) patients on the 1^st week. Raised IOP was observed in 10 (20.0%) cases whereas cystoid macular edema was observed in only 1 (2%) patients on the 1^st day and 1^st week after laser therapy.

Conclusion

The study predicted that Nd: Yag laser posterior capsulotomy gives excellent results in terms of visual acuity. Complications that were associated with the Nd: Yag laser capsulotomy was a rise in intraocular pressure, cystoid macular edema, iritis, and IOL pitting.

Preserving posterior capsular integrity in post-endothelial keratoplasty posterior capsular opacification

Endothelial keratoplasty (EK) with pseudophakia often presents with late-onset proliferative after-cataract with posterior capsule distension. We performed a modified technique of capsular bag lavage in 11 eyes with late-onset PCO after EK (4 cases: post-DSAEK, 7 cases: post-DMEK). Anterior capsular rim was separated from the underlying IOL optic using MVR blade. Circumferential relaxing radial nicks were made on the capsular rim to create space for the passage of irrigation-aspiration (IA) probes behind the IOL. Bimanual IA of the flocculent cortical material was performed without damaging the posterior capsule. Air was injected at end of surgery to ensure graft apposition. All cases gained 1-3 lines of Snellen’s acuity and no case developed graft failure, rejection, or endothelial decompensation. An intact posterior capsule is associated with better outcomes post a repeat graft, if required. Our technique helps avoid complications related to a disturbed anterior hyaloid phase and minimizes postoperative inflammation.

The Role of Optical Coherence Tomography Signal Strength in the Diagnosis and Follow-up of Patients with Posterior Capsular Opacification Treated with Nd:YAG Laser Capsulotomy

Objectives:

To investigate the relationship between optical coherence tomography (OCT) signal strength (SS) and visual acuity in patients with posterior capsule opacification (PCO) and evaluate the effect of PCO on retinal thickness measurements.

Materials and Methods:

Forty-one eyes of 35 patients who were diagnosed with PCO were included in the study. Patients with any anterior or posterior segment pathology other than PCO were excluded. After ophthalmologic examination, pupil dilation was induced using 0.5% tropicamide and OCT images were acquired. The assessment was repeated 1 month after Nd:YAG laser capsulotomy and postoperative values were compared with baseline values.

Results:

The patients’ mean best corrected visual acuity (BCVA) was 0.28±0.13 preoperatively and 0.78±0.09 postoperatively (p<0.0001). Strong positive correlations were observed between BCVA and SS both pre- and postoperatively (p<0.0001 and p=0.01, respectively). Central retinal thickness (CRT) and SS increased significantly postoperatively (p<0.0001 for both). OCT SS and CRT were strongly correlated preoperatively (p=0.001) but not postoperatively (p=0.46).

Conclusion:

OCT SS correlates with visual acuity in patients with PCO, and PCO can affect the accuracy of objective data obtained with OCT.

Short-Term Anterior Segment Changes After Nd-YAG Laser Posterior Capsulotomy in Pseudophakic Eyes with Fuchs' Endothelial Dystrophy

Purpose

To describe the changes in the central corneal thickness (CCT), endothelial cell count (ECC), intraocular lens (IOL) position, and refractive error 1 and 3 months after Nd-YAG laser posterior capsulotomy (YAG-PC) for posterior capsular opacification (PCO) in pseudophakic eyes with Fuchs' endothelial cell dystrophy (FECD).

Design

Prospective case-control.

Participants

Fifty pseudophakic eyes of 50 patients with visually significant PCO (25 with healthy corneas, and 25 with FECD grade 1 and 2).

Methods

FECD was clinically graded, and only patients without clinically evident corneal edema were included in the study (grade 1 and 2). All patients received YAG-PC and were followed up after 1 and 3 months. Best-corrected visual acuity, refractive errors, ACD, CCT, and ECC were assessed and compared between the pre-laser values and that of the 2 follow-up visits.

Results

In both groups, BCVA showed significant improvement (P<0.05). Compared to healthy controls, a significant hyperopic shift was observed in the FECD eyes at the 2 follow-up visits (P=0.027, and 0.019). A significant backward movement of the IOL was observed in the FECD eyes in the 2 follow-up visits (P=0.043, and 0.02). There was a significant correlation between the hyperopic shift in the FECD eyes and the ACD deepening during the 1st month (R= -0.6, P=0.001) and 3rd month (R= -0.4, P=0.04). Significant drop in the ECC was noted in both groups but without significant increase in the CCT.

Conclusion

Compared to controls, a hyperopic shift and backward movement of the IOL were observed in the FECD eyes after YAG-PC. No significant corneal thickening was found in both groups despite the significant drop in the ECC. Future studies are required to confirm our results and monitor the long-term changes after YAG-PC in FECD.

Surgical outcomes of modified capsular tension ring and intraocular lens implantation in Marfan syndrome with ectopia lentis

OBJECTIVE

To evaluate surgical outcomes of modified capsular tension ring (MCTR) and intraocular lens (IOL) implantation in eyes of Marfan syndrome (MFS).

METHODS

This retrospective case series included MFS patients receiving MCTR transscleral fixation and IOL in-the-bag implantation. The MCTR was sutured to the sclera through a sulcus by 9-0 polypropylene with the modified knotless Z-suture technique. Main outcomes were visual acuity and postoperative complications.

RESULTS

A total of 109 MFS patients (187 eyes) had the surgery. Patients were 15.47 ± 14.36 years old and followed up for 10.07 ± 8.99 months. MCTR and IOL implantations were performed in 174 eyes (93.05%). The postoperative BCVA (LogMAR) was 0.24 ± 0.24 (1 month), 0.26 ± 0.20 (3 months), 0.22 ± 0.20 (6 months), 0.20 ± 0.19 (12 months) and 0.25 ± 0.32 (over 12 months), which was significantly better than preoperatively (0.63 ± 0.35) (p < 0.001). Major complications included posterior capsular opacification (PCO) in 41 eyes (23.56%) and decentered anterior capsular opacification (ACO) in 15 eyes (8.62%). The mean occurrence time was 9.44 ± 7.08 and 8.87 ± 15.08 months respectively. Other complications included transient intraocular pressure elevation in seven eyes (4.02%), retinal detachment in two eyes (1.15%), cystoid macula edema in one eye (0.57%), and endophthalmitis in one eye (0.57%). No eye had suture breakage or IOL dislocation.

CONCLUSIONS

The visual improvement is significant in eyes of MFS undergoing MCTR transscleral fixation and IOL in-the-bag implantation. The long-term monitoring of complications is warranted, especially in the first-two years.

Influence of the "Inverted U Method" Nd: YAG Laser Posterior Capsulotomy on Anterior Segment Parameters, Decentration and Tilt of Intraocular Lens in Patients after Phaco-vitrectomy

PURPOSE

To investigate the effects of the "inverted U method" Nd:YAG laser posterior capsulotomy on anterior segment parameters, decentration and tilt of intraocular lens (IOLs) and visual acuity in posterior capsular opacification (PCO) patients after combined phaco-vitrectomy.

METHODS

Seventy-six patients (76 eyes) were enrolled in this study, who were diagnosed as PCO and underwent "inverted U method" Nd:YAG laser posterior capsulotomy. All patients had undergone previous combined phaco-vitrectomy for rhegmatogenous retinal detachment. The parameters including IOL decentration, angle of IOL tilt, anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), keratometry, pupil size, axial length (AL), intraocular pressure (IOP), refractive status, corrected distance visual acuity (CDVA), objective scattering index (OSI) and Chinese version of Visual Function 14 (VF-14) index were obtained before and 3 months after capsulotomy.

RESULTS

After capsulotomy, the tilt angle and decentration of the IOLs at both vertical (tilt: p = .004, decentration: p = .029) and horizontal meridian (tilt: p = .001, decentration: p = .017) were significantly decreased, ACA increased (p = .015), CDVA (p = .000), VF-14 score (p = .000) and OSI (p = .000) were significantly improved. There were a significant decrease in cylindrical error (p = .001) and a myopic shift in spherical error (p = .001) after the capsulotomy. No significant differences in ACD, ACV, CCT, keratometry, pupil size, AL and IOP were detected (p > .05 for all).

CONCLUSION

The "inverted U method" Nd: YAG laser posterior capsulotomy decreases tilt and decentration of the IOL, increases ACA and causes no change in ACD, ACV, CCT and IOP in patients after phaco-vitrectomy. These changes make a decrease in cylindrical error and a myopic shift in spherical error. Laser capsulotomy significantly improves visual acuity.

Surface Modification of Intraocular Lens with Hydrophilic Poly(Sulfobetaine Methacrylate) Brush for Posterior Capsular Opacification Prevention

Purpose: The intraocular lens (IOL) is a common, yet important, implantable device used in treatment of cataract in clinics. However, the unexpected adhesion of postoperative residual lens epithelial cells (LECs) often causes serious complications, such as posterior capsular opacification (PCO), which lead to vision loss again. In this investigation, a poly(sulfobetaine methacrylate) (PSBMA) brush coating was fabricated on an IOL to generate a hydrophilic surface coating on the IOL for enhanced cell adhesion resistance so as to decrease PCO incidence. Methods: The PSBMA brush coating on the IOL surface was fabricated using surface-initiated reversible addition-fragmentation chain transfer polymerization. X-ray photoelectron spectroscopy (XPS) was used to demonstrate the surface coating preparation. The water contact angle (WCA) measurement was used to test surface hydrophilicity. In vitro LEC culture was use to evaluate the cell behavior on the IOL material surfaces, with or without PSBMA coating modification. Finally, animal cataract surgeries were carried out to evaluate in vivo biocompatibilities and anti-PCO effects. Results: The XPS and WCA measurements illustrate successful surface modification and good surface hydrophilicity. The in vitro cell culture results show that the hydrophilic PSBMA polymer brush coating evidently decreases adhesion and proliferation of LECs. Results of the in vivo cataract surgery with intraocular implantation show that PSBMA modification on the IOL surface does not induce side effects in nearby tissues, whereas posterior capsular hyperplasia can be evidently reduced. Conclusion: The PSBMA brush surface-modified IOL has good in vivo biocompatibility and it can effectively reduce the incidence of postoperative PCO.

Drug-Eluting Hydrophilic Coating Modification of Intraocular Lens via Facile Dopamine Self-Polymerization for Posterior Capsular Opacification Prevention

Posterior capsular opacification (PCO) is the most important complication in cataract phacoemulsification and intraocular lens (IOL) implantation surgery, mainly stemming from the adhesion, proliferation, and transdifferentiation of the postsurgically residual lens epithelial cells (LECs). Previous investigations mainly focused on the hydrophilic surface modification of the IOLs for PCO prevention, such as heparinization. However, the long-term clinical investigations show that there is no significant difference between pristine and heparinized IOLs. In the present study, a synergetic coating with properties of drug-eluting and hydrophilicity was designed and modified onto the IOL surface via facile dopamine self-polymerization. The antiproliferative drug doxorubicin (DOX) was loaded when a polydopamine (PDA) coating was formed on the IOL surface. The hydrophilic 2-methacryloyloxyethyl phosphorylcholine (MPC) could be subsequently grafted onto the drug-loaded PDA coating surface easily. The hydrophilic outer layer could slow down drug-eluting from underneath the drug-incorporated coating. In vitro and in vivo investigations demonstrated that such multifunctionalized coating-modified IOLs could not only thoroughly and effectively prevent PCO development by induced cell apoptosis but also render safety and biocompatibility to the surrounding tissues.

Clear lens extraction for patients who are unfit for laser-assisted in situ keratomileusis and implantable contact lenses in central Indian population

Purpose:

The purpose of this study is to establish the safety of clear lens extraction (CLE) for the correction of high myopia in patients unfit for implantable contact lenses (ICLs) and laser in situ keratomileusis in the central Indian population.

Methods:

In this retrospective observational study performed at a tertiary care centre, medical records of the patients who had undergone CLE with implantation of intraocular lens (IOL) to treat high myopia were retrieved. Details of the demographic profile, surgical procedure, complications, power, and type of IOLs implanted were recorded.

Results:

The average postoperative follow-up period was 64.1 ± 4.2 months. The average postoperative spherical power was −1.4 ± 0.6 D, which was much lower than the preoperative spectacle power - 15 ± 4.4 D. There was improvement in the postoperative visual acuity (0.4 ± 0.2 logMAR) from the preoperative distant uncorrected visual acuity (0.8 ± 0.2 logMAR). No significant change in intraocular pressure (IOP) was observed. The postoperative average anterior chamber depth (ACD) (2.66 ± 0.1 mm) was significantly deeper than the preoperative ACD (2.61 ± 0.1 mm) P = 0.00. Barrage laser was required for lattice degeneration in one patient before CLE and in two patients during follow-up. Two patients (8.7%) required Nd:YAG capsulotomy for posterior capsular opacification. None of the patients had corneal decompensation, retinal detachment, or endophthalmitis.

Conclusion:

CLE with implantation of IOL is the safe procedure for correcting high myopia in patients who are unfit for ICL. None of the patient had eye loss in the follow-up period of 5 years. The low incidence of complications can be attributable to the closed chamber lens removal and implantation of IOL and prophylactic retinal treatment.

Vitamin C decreases VEGF expression levels via hypoxia‑inducible factor‑1α dependent and independent pathways in lens epithelial cells

Posterior capsular opacification (PCO) is the main complication following cataract surgery. The proliferation of the residual lens epithelial cells (LECs) serves an important role in PCO formation. The authors' previous study revealed that vitamin C inhibited the proliferation of human LECs by increasing the rapid degradation of hypoxia-inducible factor-1 (HIF-1α), and hence inhibited the expression of vascular endothelial growth factor (VEGF). The present study aimed to further investigate the mechanisms underlying the effects of vitamin C on the expression levels of VEGF. The present study demonstrated that the HIF-1 inhibitor BAY 87–2243 significantly inhibited the cell proliferation and the expression levels of VEGF in LECs through the use of colony formation, western blotting and ELISA assays. Moreover, it was revealed that vitamin C could further inhibit the cell proliferation and the expression levels of VEGF in LECs following the cotreatment with the HIF-1 inhibitor. The proline hydroxylation of HIF-1α by prolyl hydroxylases (PHDs) was previously discovered to be responsible for the rapid degradation of HIF-1α. Thus, the present study subsequently used three PHD inhibitors to investigate their effects on the expression levels of VEGF; it was found that the PHD2 specific inhibitor increased the expression levels of VEGF to the greatest extent. Moreover, the genetic knockdown of PHD2 by lentiviral transfection also significantly increased the expression levels of VEGF, whereas the PHD2 specific inhibitor did not alter the expression levels of VEGF in the PHD2 knockdown LECs. AKT kinase activity is an important mediator known to upregulate VEGF expression. Using an immunoprecipitation assay to isolate endogenous AKT, it was demonstrated that AKT was prolyl hydroxylated by PHD2, which inhibited its activity. It was also revealed that vitamin C enhanced the proline-hydroxylation and inhibited the activity of AKT. Furthermore, an AKT inhibitor increased the effects of vitamin C on the expression levels of VEGF. However, the AKT inhibitor did not affect the expression levels of glucose transporter 1, which is a HIF-1α target gene. In conclusion, the findings of the present study suggested that vitamin C may inhibit the expression levels of VEGF via HIF-1α-dependent and AKT-dependent pathways in LECs.

Retro-intraocular Lens Irrigation-aspiration to Prevent Capsular Block Syndrome at the Hands of Novice Surgeons

Retro-intraocular lens (IOL) irrigation-aspiration is of paramount importance in order to remove the viscoelastic substance from the retro-IOL space and to prevent any early post-operative capsular block syndrome. However, manoeuvring the IOL to reach the retro-IOL space may be difficult at the hands of novice surgeons despite the use of coaxial or bimanual irrigation-aspiration probes. We describe a simpler and safer technique in order to facilitate the removal of this retro-IOL viscoelastic substance using a 26-Gauge bent-cannula mounted on a 2-ml syringe. The fluid is injected forcefully along with sideways movement of cannula in a single-plane to displace the viscoelastic substance.

Rotation versus non-rotation of intraocular lens for prevention of posterior capsular opacification

Purpose:

To study the effect of rotation of intraocular lens (IOL) on posterior capsular opacification (PCO) in eyes with phacoemulsification.

Methods:

This was a prospective, comparative, randomized case series. One eye of each patient was randomized to one of two groups. The 360-degree rotation of IOL was carried out after its placement in the capsular bag (rotation group). The control group had no rotation of IOL. PCO was analyzed by an independent observer on EPCO computer analysis system at 6, 12, 24, and 36 months.

Results:

The study included 50 patients (100 eyes) with senile cataracts scheduled for phacoemulsification and IOL implantation. The median age in 2 groups was 66 years. 25% quartile age in both the group was 62 years (P = 0.06). There were 30 males, and 20 females. The median PCO score at 6, 12 and 24 months was significantly low in the rotation group (0.15, 0.13, 0.22) compared to the control group (0.22, 0.23, 0.25). There was no significant difference in PCO score between the two groups from 24-36 months. The median PCO score at 36 months was 0.2 in both the groups. At the end of three years, 4 eyes (8%) in the rotation group, and 10 eyes (20%) in the control group needed Nd:YAG capsulotomy (P = 0.04).

Conclusion:

Rotation of IOL in the capsular bag decreases PCO and Nd:YAG capsulotomy rate.

Anti-Adhesive And Antiproliferative Synergistic Surface Modification Of Intraocular Lens For Reduced Posterior Capsular Opacification

BACKGROUND

Posterior capsular opacification (PCO) is the main complication after intraocular lens (IOL) implantation in cataract surgery, which is the result of lens epithelial cell (LEC) adhesion, proliferation and migration on the IOL and at the lens capsule interface. Hydrophilic surface modification, such as surface heparinization, decreases the cell adhesion, which has been commercialized and used clinically. However, clinical long-term observation results show no significant difference between the pristine and heparinized IOLs.

METHODS

To prevent PCO over the long time span, we modified the IOLs with an antiproliferative drug-loaded hydrophilic coating. The antiproliferative drug doxorubicin (DOX)-incorporated chitosan (CHI) nanoparticle was fabricated by sodium tripolyphosphate (TPP) gelation. Such antiproliferative drug-loaded CHI-TPP-DOX nanoparticles (CTDNP) were used as one of the building blocks to prepare polyelectrolyte multilayer with heparin (HEP) via layer-by-layer assembly, obtaining (HEP/CTDNP)n multilayers. The assembly process was characterized by quartz crystal microbalance with dissipation (QCM-D). The drug release behavior of the coating was investigated by ultra-HPLC (UPLC). In vitro cell experiments were carried out to monitor the effects of multifunctional coatings on cellular adhesion, proliferation and migration. And the intraocular implantation was performed on rabbits to evaluate the in vivo PCO inhibitory effect of such surface-functionalized IOLs.

RESULTS

The positively charged CTDNP was successfully prepared by ionic gelation. The QCM-D results indicate the successful preparation of the (HEP/CTDNP)n multilayer film. Drug release profiles showed that surface-multifunctionalized IOL had drug-sustained release properties. In vitro cell culture results showed significant inhibition of adhesion, proliferation and migration of LECs after surface modification. The in vivo results showed that the IOLs with multifunctionalized surface can effectively reduce the posterior hyperplasia and Soemmering's ring (SR) formation.

CONCLUSION

These findings suggested that such multifunctionalized drug-eluting IOLs can effectively reduce the posterior hyperplasia and SR formation when intraocular implantation has a major impact on reducing PCO incidence. Thus they have a great potential in improving patient vision recovery and maintenance.

Cataract surgeon viewpoints on the need for novel preventative anti-inflammatory and anti-posterior capsular opacification therapies

Purpose: To determine cataract surgeon viewpoints on the efficacy of available therapies/preventatives for two common sequelae of cataract surgery: inflammation and posterior capsular opacification (PCO). Methods: Cataract surgeons practicing worldwide specializing in adult, pediatric and veterinary patients were interviewed between March and August 2018. Results: Ocular inflammation following cataract surgery is treated by either corticosteroids and/or nonsteroidal anti-inflammatories (NSAIDs). Adult and pediatric cataract surgeons are satisfied with current treatments whereas this inflammation is still considered a problem by some in veterinary practice due to its slow resolution. Yttrium-aluminum-garnet (YAG) laser therapy is the PCO treatment of choice for adult cataract surgeons and they are generally pleased with its outcome. However, pediatric cataract surgeons find YAG problematic, especially in patients under 6 years of age, and invasive surgery is often needed to correct PCO/visual axis opacification (VAO). Veterinary ophthalmologists report that YAG is not effective for PCO in animals, especially dogs, due to the density of the fibrotic plaques; 86% of adult and 100% of veterinary and pediatric cataract surgeons surveyed agree that effective anti-PCO therapeutics would improve clinical care. Conclusions: Surgeons treating human patients are pleased with the available treatments for ocular inflammation following cataract surgery, although some veterinary ophthalmologists disagree. The surgeons surveyed agree that PCO/VAO remains an unsolved problem in pediatric and veterinary cataract surgery while the long-term outcome of adult cataract surgery could be improved by additional attention to this issue.

Quantification of Inflammation Following Nd:YAG Laser Capsulotomy and Assessing the Anti-inflammatory Effects of Nepafenac 0.1% and Betamethasone 0.1

Purpose: To quantify the intraocular inflammation, measured using laser flare photometry (LFP), after Nd:YAG capsulotomy and compare the effects of different topical anti-inflammatory regimes.Methods: A single-center, prospective, randomized controlled study, which included 90 eyes of 90 patients with visually significant posterior capsular opacification. In all patients, Nd:YAG capsulotomy was done and was then randomized into three groups: (A) Topical betamethasone 0.1%; (B) Topical nepafenac 0.1%; and (C) Control group: did not receive any anti-inflammatory agent post capsulotomy.Results: There was a significant increase in the mean LFP values 2 h following laser capsulotomy (p < 0.001) and then declined gradually and came back to pre-laser values by 2 weeks in all three groups. The mean LFP values, central macular thickness, and best corrected visual acuity were comparable among groups. None developed central macular edema.Conclusion: Intraocular inflammation following Nd:YAG capsulotomies is minimal and transient. Routine use of prophylactic anti-inflammatory agents may be avoided.

Gremlin is a potential target for posterior capsular opacification

Objective: The present study was conducted to determine the role of gremlin during the development of posterior capsular opacification (PCO) via in vitro and in vivo experiments. Methods: The activation, roles and relationships of the BMPs/Smad1/5, MAPK, FAK and AKT signaling pathways in human lens epithelial cells (HLECs) after gremlin induction were detected by western blotting and real-time PCR. Wound-healing, transwell, capsular bag models and rat PCO models assays were used to test the effects of gremlin on HLECs' migration, proliferation, EMT-specific protein α-smooth muscle actin（α-SMA）and development of PCO in rats. Results: Our data showed that knockdown of the gremlin inhibited the development of PCO and reduced expression of α-SMA in rats. While gremlin did not alter the migration of HLECs, it increased the expression of p-ERK and p-AKT. Knockout of Smad2 or Smad3 inhibited the expression of p-ERK and p-AKT proteins induced by gremlin. Gremlin also reduced BMP4-induced expression of the p-Smad1/5 protein. Finally, knockout of Smad1/5 increased gremlin-induced expression of α-SMA, fibronectin and type I collagen (COL-1) in HLECs. Conclusion: These results suggested that gremlin contributed to the development of PCO by promoting LEC proliferation, activation of TGF-β/Smad, ERK and AKT signaling and inhibition of BMPs/Smad1/5 signaling. Furthermore, inhibiting gremlin effectively impaired both PCO development in rats and EMT in the lens capsule. Thus, our data suggest that gremlin might be a potential target for PCO.

Pediatric Nd:YAG laser capsulotomy in the operating room: review of 87 cases

AIM

To report a large series of children having Nd:YAG laser capsulotomy in the operating room using the lateral decubitus position.

METHODS

Medical records of children who underwent Nd:YAG laser capsulotomy in the operating room at Ann & Robert H. Lurie Children's Hospital of Chicago between September 2008 and April 2017 were reviewed. Induction of general anesthesia and intubation was performed in the supine position after which the patient was placed in lateral decubitus position. The Nd:YAG laser capsulotomy was performed using a standard protocol. At the completion of the procedure, the patient was turned back into the supine position and extubated.

RESULTS

This study included 87 eyes of 60 patients. Patient's age ranged from 1 to 18y (mean 6.4±4.1y). In most cases (84/87, 97%), the procedure was performed under general anesthesia. In all cases, good focus on the membrane was achieved, and the procedure was performed successfully. There were no intraoperative ocular or anesthesia-related complications.

CONCLUSION

When performing Nd:YAG laser capsulotomy in the operating room, the lateral decubitus position allows an easy and safe approach without the risk of potentially devastating complications that have been associated with the previously described sitting and prone positions.

Reopacification of posterior capsular opening after ND: YAG capsulotomy: 2 cases with the different presentation

Purpose: To report the complete opacification of posterior capsulotomy opening after neodymium: yttrium-aluminium-garnet (ND: YAG) posterior capsulotomy for posterior capsular opacification. Methods: A 70-year-old female had uneventful cataract surgery by phacoemulsification technique with implantation of in the bag hydrophilic intraocular lens (IOL) in her left eye. Eight months after surgery, the patient developed posterior capsular opacification (PCO) for which ND: YAG capsulotomy was performed. However, she returned after 7 months first post ND: YAG capsulotomy with the blurring of vision and glare at night. Slit lamp examination revealed pearl like opacification of posterior capsule occupying the YAG capsulotomy opening. A repeated ND: YAG capsulotomy restored her vision to 20/ 20. Another patient operated for posterior polar cataract had dehiscence in the posterior capsule during cataract surgery. The patient was implanted with hydrophobic IOL in the capsular bag without performing an optic capture. The patient presented 3 years later with occlusion of the posterior capsular opening with mixed pearl-like and fibrotic PCO. Conclusion: Occlusion of the posterior capsular opening may occur after ND: YAG capsulotomy and may cause a reduction in visual acuity. Pearl-like opacification is common to occur in reopacification of posterior capsular opening.

Glistenings, anterior/posterior capsular opacification and incidence of Nd:YAG laser treatments with two aspheric hydrophobic acrylic intraocular lenses - a long-term intra-individual study

PURPOSE

To compare two hydrophobic acrylic intraocular lenses (IOLs) regarding long-term anterior/posterior capsular opacification (ACO/PCO) development and need for neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser treatment due to visually disturbing PCO, and to study development of glistenings in the IOL materials.

METHODS

In a prospective, randomized, intra-individual, comparative trial, 50 cataract patients received either an AcrySof IQ^® SN60WF (Alcon, Fort Worth, TX, USA) or a Tecnis^® ZCB00 (Abbott Medical Optics, Santa Ana, CA, USA) IOL in the first operated eye, and the second eye received the IOL type not implanted in the first eye. Anterior/posterior capsular opacification (ACO/PCO) and fibrosis were monitored with slit-lamp photography and semi-automated digital analysis 2 and 3 years postoperatively. Glistenings were semi-quantitatively assessed in slit-lamp photographs. Nd:YAG laser treatment for visually disturbing PCO was monitored.

RESULTS

Visual outcomes were similar for the two IOLs. Anterior capsular fibrosis and/or opacification developed more often in SN60WF eyes. Mean PCO area percentage was larger in ZCB00 eyes 3 years after surgery, but severity score did not differ with statistical significance between the two IOLs. Six ZCB00 eyes and 2 SN60WF eyes underwent Nd:YAG laser treatment during a mean of 4 years 8 months after surgery. This difference was not statistically significant. A high amount of glistenings developed in most SN60WF IOLs, while only few ZCB00 IOLs displayed a low degree of glistenings.

CONCLUSION

Visual outcomes, PCO development over time and need for Nd:YAG laser treatment were similar for the two IOLs. Anterior capsule fibrosis/contraction and glistenings were more pronounced with the SN60WF IOL.

Posterior Capsular Opacification in Preschool- and School-Age Patients after Pediatric Cataract Surgery without Posterior Capsulotomy

Objectives:

We aimed to evaluate the development of posterior capsular opacification (PCO) in preschool- and school-age children with cataract who underwent cataract surgery without posterior capsulotomy and anterior vitrectomy.

Materials and Methods:

The records of 30 eyes of 21 patients who underwent pediatric cataract surgery and intraocular lens (IOL) implantation were retrospectively reviewed. Patients’ age, PCO status and duration, need for neodymium-doped yttrium aluminium garnet (Nd:YAG) laser treatment based on coverage of visual axis, and follow-up period were recorded.

Results:

The mean age of the patients was 7.6±2.83 (4-12) years. Unilateral cataract surgery and IOL implantation were performed in 12 patients (57.14%) and bilateral cataract surgery and IOL implantation were performed in nine patients (42.86%). Average follow-up time was 17.7±22.67 (3-83) months. PCO developed in 21 eyes (70%) and covered the visual axis in 15 eyes (50%), which therefore required Nd:YAG laser posterior capsulotomy. The mean duration of postoperative PCO development was 8.91±18.7 months (1 week-71 months).

Conclusion:

We believe that with adequately experienced surgeons, performing both cataract surgery and posterior capsulotomy with anterior vitrectomy in the same session is appropriate for selected preschool- and school-age children with cataract.

AGEs in human lens capsule promote the TGFβ2-mediated EMT of lens epithelial cells: implications for age-associated fibrosis

Proteins in basement membrane (BM) are long‐lived and accumulate chemical modifications during aging; advanced glycation endproduct (AGE) formation is one such modification. The human lens capsule is a BM secreted by lens epithelial cells. In this study, we have investigated the effect of aging and cataracts on the AGE levels in the human lens capsule and determined their role in the epithelial‐to‐mesenchymal transition (EMT) of lens epithelial cells. EMT occurs during posterior capsule opacification (PCO), also known as secondary cataract formation. We found age‐dependent increases in several AGEs and significantly higher levels in cataractous lens capsules than in normal lens capsules measured by LC‐MS/MS. The TGFβ2‐mediated upregulation of the mRNA levels (by qPCR) of EMT‐associated proteins was significantly enhanced in cells cultured on AGE‐modified BM and human lens capsule compared with those on unmodified proteins. Such responses were also observed for TGFβ1. In the human capsular bag model of PCO, the AGE content of the capsule proteins was correlated with the synthesis of TGFβ2‐mediated α‐smooth muscle actin (αSMA). Taken together, our data imply that AGEs in the lens capsule promote the TGFβ2‐mediated fibrosis of lens epithelial cells during PCO and suggest that AGEs in BMs could have a broader role in aging and diabetes‐associated fibrosis.

Sustained-release genistein from nanostructured lipid carrier suppresses human lens epithelial cell growth

AIM

To design and investigate the efficacy of a modified nanostructured lipid carrier loaded with genistein (Gen-NLC) to inhibit human lens epithelial cells (HLECs) proliferation.

METHODS

Gen-NLC was made by melt emulsification method. The morphology, particle size (PS), zeta potentials (ZP), encapsulation efficiency (EE) and in vitro release were characterized. The inhibition effect of nanostructured lipid carrier (NLC), genistein (Gen) and Gen-NLC on HLECs proliferation was evaluated by cell counting kit-8 (CCK-8) assay, gene and protein expression of the proliferation marker Ki67 were evaluated with real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence analyses.

RESULTS

The mean PS of Gen-NLC was 80.12±1.55 nm with a mean polydispersity index of 0.11±0.02. The mean ZP was -7.14±0.38 mV and the EE of Gen in the nanoparticles was 92.3%±0.73%. Transmission electron microscopy showed that Gen-NLC displayed spherical-shaped particles covered by an outer-layer structure. In vitro release experiments demonstrated a prolonged drug release for 72h. The CCK-8 assay results showed the NLC had no inhibitory effect on HLECs and Gen-NLC displayed a much more prominent inhibitory effect on cellular growth compared to Gen of the same concentration. The mRNA and protein expression of Ki67 in LECs decreased significantly in Gen-NLC group.

CONCLUSION

Sustained drug release by Gen-NLCs may impede HLEC growth.

Surface PEGylation of intraocular lens for PCO prevention: An in vivo evaluation

Posterior capsular opacification (PCO) is a common complication in cataract surgery. The development of PCO is attributed to the combination of adhesion, migration, proliferation, and transdifferentiation of the residual lens epithelial cells (LEC) onto the interface of intraocular lens (IOL) material and lens posterior, in which the initial adhesion is the beginning step and plays important roles. In the present study, hydrophilic polyethylene glycol (PEG) was immobilized onto IOL surface via plasma-aided chemical grafting procedure. The attenuated total reflection - Fourier transform infrared (ATR-FTIR) and contact angle (CA) - measurements indicate the successful surface PEGylation, as well as the excellent hydrophilicity of the surfaces. Compared with pristine IOL, the PEGylation does not influent its optical property, whereas the initial adhesion of LEC is greatly inhibited. In vivo ocular implantation results show that the PEGylated IOL presents good in vivo biocompatibility, and can effectively prevent the PCO development.

Effects of lentiviral RNA interference-mediated downregulation of integrin-linked kinase on biological behaviors of human lens epithelial cells

AIM

To investigate the effects of lentivirus (LV) mediated integrin-linked kinase (ILK) RNA interference (RNAi) on biological behaviors of human lens epithelial cells (LECs).

METHODS

Human cataract LECs and immortalized human LEC line, human lens epithelial (HLE) B-3 cells were transfected by lentiviral vector expressing ILK-specific short hairpin RNA (shRNA) and then stimulated by transforming growth factor-β (TGF-β), the silencing of ILK gene and protein was identified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot methods; biological behaviors including cell cycle and apoptosis, cell morphology, α-smooth muscle actin (SMA) stress fiber formation and cell migration were examined.

RESULTS

Remarkable decreases of ILK protein expression were detected in LECs carrying lentiviral ILK-shRNA vector; flow cytometry revealed arresting of cell cycle progression through the G1/S transition and higher apoptosis rate in ILK-RNAi-LV transfected cells. Less α-SMA stress fiber formation and migration was observed in ILK-RNAi-LV transfected LECs.

CONCLUSION

The present study demonstrated that ILK was an important regulator for LECs proliferation and migration. LV mediated ILK RNAi is an effective way to decrease ILK-regulated cell growth by arresting cell cycle progression and increasing cell apoptosis, as well as, to prevent cell migration by inhibiting TGF-β induced α-SMA stress fiber formation. Thus, LV mediated ILK RNAi might be useful to prevent posterior capsular opacification.

Vitamin C inhibit the proliferation, migration and epithelial-mesenchymal-transition of lens epithelial cells by destabilizing HIF-1α

Posterior capsular opacification (PCO), the main complication of cataract surgery, is mainly caused by the proliferation, migration, and epithelial-mesenchymal transition (EMT) of the residual lens epithelial cells (LECs).Vitamin C was reported to reduce the risk of forming a cataract. However, there has been no study showing the association between vitamin C and PCO. In this study, we found that vitamin C could inhibit the migration and proliferation of human lens epithelial cells. We also found that vitamin C could increase the proline hydroxylation of HIF-1α and reduce the activity of HIF-1α. Moreover, vitamin C could not inhibit the activity of proline-mutant HIF-1α (402/564). Overexpression of wild-type HIF-1α or proline-mutant HIF-1α was found to increase the proliferation and migration of human lens epithelial cells. Differently, vitamin C could inhibit the proliferation and migration in wild-type HIF-1α-overexpressing lens epithelial cells but not the proline-mutant HIF-1α-overexpressing cells. Additionally, vitamin C was also found to inhibit the expression of EMT transcription factors TWIST. We then found that vitamin C could repress the EMT phenotypes induced by the overexpression of wild-type HIF-1α but not the proline-mutant HIF-1α. These results provide evidence that vitamin C plays a role in the repression of proliferation, migration, and EMT of human lens epithelial cells by destabilizing HIF-1α.

Morphological and proliferative studies on ex vivo cultured human anterior lens epithelial cells - relevance to capsular opacification

PURPOSE

To determine the structural characteristics of lens epithelial cells (LECs) found on the anterior portion of the lens capsule and their pluripotency, proliferating and migrating potential when grown ex vivo with relevance to posterior capsular opacification (PCO) after cataract surgery.

METHODS

The explants of anterior portion of the lens capsule consisting of monolayer of LECs were obtained from uneventful cataract surgery and were cultivated under adherent conditions. The size and shape of the outgrowing cells were recorded by scanning electron microscopy (SEM), while their migration and proliferation potential were followed using light microscopy. Positivity for proliferation (Ki-67)- and pluripotency (Sox2)-specific markers were tested by immunofluorescent staining.

RESULTS

The proliferation and migration of anterior portion of the lens capsule's LECs filling up the denuded and reverse side regions of the lens capsule as well as their growth on glass culture surfaces could be followed by light microscopy and SEM, while the distribution of LECs and their morphology could be analysed in detail by SEM. The expression of Ki-67 and Sox2 in LECs growing adherently on human anterior portion of the lens capsule could also be detected.

CONCLUSIONS

Classic light microscopy and SEM can be used to show that human anterior portion of the lens capsule harbours LECs that can proliferate and migrate, suggesting their pluripotency or putative stem cell nature. Similarly, morphological techniques can be used to study PCO and the effect different drugs or physical treatments have against PCO development.

Posterior capsular opacification and Nd:YAG capsulotomy rates with the iMics Y-60H and Micro AY intra-ocular lenses: 3-year results of a randomized clinical trial

PURPOSE

To compare the incidence and intensity of posterior capsular opacification (PCO) and neodymium:yttrium-aluminium-garnet (Nd:YAG) capsulotomy rates between two microincision intra-ocular lenses (IOLs) 3 years after surgery.

METHODS

Sixty-five patients randomly received a Y-60H IOL (HOYA Surgical Optics, Singapore) in one eye and a Micro AY IOL (PhysIOL, Liège, Belgium) in the contralateral eye during same-day bilateral cataract surgery. Eyes were examined 1 week, 20 months and 3 years after surgery. The amount of PCO (score: 0-10) was assessed subjectively at the slit lamp and objectively using automated image analysis software (aqua). Additionally, the Nd:YAG capsulotomy rate was noted.

RESULTS

Three years postoperatively, the objective PCO score of Y-60H IOLs was 1.9 ± 1.7 compared to PCO score of 1.7 ± 2.2 for the Micro AY IOLs (p = 0.66). Thirty-four percentage of the Y-60H eyes had undergone Nd:YAG capsulotomy, compared to 49% of the Micro AY eyes (p = 0.04). Significantly, more capsular folds were observed in the Y-60H IOL group (p = 0.001). There was no significant difference in best-corrected visual acuity, rhexis/IOL overlap and anterior capsule opacification 3 years after surgery.

CONCLUSION

Both microincision IOLs showed high YAG rates and comparable PCO scores 3 years after surgery. In the light of this unsatisfying PCO performance, the advantage of the present microincision IOLs over conventional IOLs must be questioned.

The effects of Nd:YAG laser capsulotomy on anterior segment parameters in patients with posterior capsular opacification

BACKGROUND

The aim was to investigate the effects of neodymium-doped yttrium aluminum garnet laser capsulotomy on the main numerical parameters of the anterior segment with Pentacam in patients with opacification of the posterior capsule.

METHODS

Thirty eyes of 30 patients (19 male, mean age 66.9 ± 8.1 years) with visually significant posterior capsular opacification were enrolled. Patients had undergone phacoemulsification surgery with three-piece intraocular lens (Sensar, AMO, USA) implantation. Full ocular examination was performed before and after capsulotomy. Intraocular pressure (Goldmann applanation tonometry) and refractive changes were measured. Pentacam measurements of the patients before and one week and one month after capsulotomy were obtained.

RESULTS

Mean visual acuity (logMAR) improved pre-operatively (0.50 ± 0.36) to one week (0.04 ± 0.07) and one month after capsulotomy (0.03 ± 0.06; p < 0.001). Mean spherical and cylindrical powers were 0.50 ± 0.98 DS and -1.61 ± 1.00 DC before the procedure and 0.10 ± 0.80 DS and -0.92 ± 0.66 DC at one month, respectively. There was a significant decrease in cylindrical errors (p = 0.001) and a myopic shift in spherical errors (p = 0.01) after the procedure. Mean anterior chamber depth (ACD) was 4.26 ± 0.63 mm before the procedure, 3.73 ± 0.56 mm at one week and 3.75 ± 0.56 mm at one month. The decrements in anterior chamber depth were significant (p < 0.001). The mean of the anterior chamber angle measurements was 43.41 ± 6.87 degrees before the procedure, increased to 45.56 ± 7.01 degrees at one week and decreased to 44.56 ± 6.13 degrees at one month. The increments in anterior chamber angle at the first week of the procedure were significant (p = 0.01). Mean central corneal thickness was 549.60 ± 41.70 μm before the procedure, increased to 551.40 ± 39.72 μm at one week and decreased to 542.30 ± 35.48 μm at one month. The decrements in central corneal thickness were significant (p = 0.048).

CONCLUSION

Mean anterior chamber depth decreased by approximately 0.5 mm after capsulotomy. This decrement in anterior chamber depth might be a clue for associated complications, such as unwelcome refractive errors, changes at intraocular lens position, post-procedure intraocular pressure increases and acute glaucoma.

The Zeb proteins δEF1 and Sip1 may have distinct functions in lens cells following cataract surgery

PURPOSE

Posterior capsular opacification (PCO), the most prevalent side effect of cataract surgery, occurs when residual lens epithelial cells (LECs) undergo fiber cell differentiation or epithelial-to-mesenchymal transition (EMT). Here, we used a murine cataract surgery model to investigate the role of the Zeb proteins, Smad interacting protein 1 (Sip1) and δ-crystallin enhancer-binding factor 1 (δEF1), during PCO.

METHODS

Extracapsular extraction of lens fiber cells was performed on wild-type and Sip1 knockout mice. Protein expression patterns were assessed at multiple time points after surgery using confocal immunofluorescence. βB1-Crystallin mRNA levels were measured using quantitative RT-PCR. We used Transfac searches to identify δEF1 binding sites in the βB1-crystallin promoter and transfection analysis to test the ability of δEF1 to regulate βB1-crystallin expression.

RESULTS

δEF1, which, in other systems, can activate fibrotic genes (e.g., α-smooth muscle actin) and repress epithelial genes, upregulates by 48 hours after fiber cell removal. In culture, δEF1 repressed βB1-crystallin promoter activity, suggesting that it may also turn off lens gene expression following surgery, contributing to "fibrotic PCO" development. Sip1 also upregulates in LECs by 48 hours, but analysis of Sip1 knockout lenses demonstrated that Sip1 does not play a major role in EMT or fiber cell differentiation after surgery. However, Sip1 knockout LECs do express the ectodermal marker keratin 8, suggesting that Sip1 may limit the reprogramming of residual LECs to an embryonic state.

CONCLUSIONS

Zeb transcription factors likely play important, but distinct roles in PCO development after cataract surgery.

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 and 1.2 mJ/pulse was consumed and mean total energy levels were 74±21 mJ (mean±standard deviation: SD, from 40 to 167) and laser shots aimed at 150 µm 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 77 eyes) 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.

The roles of αV integrins in lens EMT and posterior capsular opacification

Posterior capsular opacification (PCO) is the major complication arising after cataract treatment. PCO occurs when the lens epithelial cells remaining following surgery (LCs) undergo a wound healing response producing a mixture of α-smooth muscle actin (α-SMA)-expressing myofibroblasts and lens fibre cells, which impair vision. Prior investigations have proposed that integrins play a central role in PCO and we found that, in a mouse fibre cell removal model of cataract surgery, expression of αV integrin and its interacting β-subunits β1, β5, β6, β8 are up-regulated concomitant with α-SMA in LCs following surgery. To test the hypothesis that αV integrins are functionally important in PCO pathogenesis, we created mice lacking the αV integrin subunit in all lens cells. Adult lenses lacking αV integrins are transparent and show no apparent morphological abnormalities when compared with control lenses. However, following surgical fibre cell removal, the LCs in control eyes increased cell proliferation, and up-regulated the expression of α-SMA, β1-integrin, fibronectin, tenascin-C and transforming growth factor beta (TGF-β)-induced protein within 48 hrs, while LCs lacking αV integrins exhibited much less cell proliferation and little to no up-regulation of any of the fibrotic markers tested. This effect appears to result from the known roles of αV integrins in latent TGF-β activation as αV integrin null lenses do not exhibit detectable SMAD-3 phosphorylation after surgery, while this occurs robustly in control lenses, consistent with the known roles for TGF-β in fibrotic PCO. These data suggest that therapeutics antagonizing αV integrin function could be used to prevent fibrotic PCO following cataract surgery.

Effects of transforming growth factor β2 and connective tissue growth factor on induction of epithelial mesenchymal transition and extracellular matrix synthesis in human lens epithelial cells

AIM

To investigate the effects of transforming growth factor β2 (TGF-β2) and connective tissue growth factor (CTGF) on transdifferentiation of human lens epithelial cells (HLECs) cultured in vitro and synthesis of extracellular matrix (ECM).

METHODS

HLECs were treated with TGF-β2 (0, 0.5, 1.0, 5, 10µg/L) and CTGF (0, 15, 30, 60, 100µg/L) for different times (0, 24, 48, 72h) in vitro and the expression of α-smooth muscle actin (α-SMA), the main component of the extracellular matrix type I collagen (Col-1) and fibronectin (Fn) were measured by using real-time polymerase chain reaction (PCR) and western-blot.

RESULTS

TGF-β2 and CTGF significantly increased expression of α-SMA mRNA and protein (P<0.05, P<0.001), Fn mRNA and protein (P<0.001), Col-1 mRNA and protein (P<0.001). TGF-β2 could induce HLECs expression of CTGF mRNA and protein in dose-dependent manner (P<0.05, P<0.001). TGF-β2 and CTGF could induce HLECs to express α-SMA, Fn and Col-1 in time-dependent manner. Each time of TGF-β2 and CTGF induced HELCs expression of α-SMA, Fn, Col-1 mRNA and protein was significant increase compared with control (P<0.05, P<0.001).

CONCLUSION

TGF-β2 and CTGF could induce HLECs epithelial mesenchymal transition and ECM synthesis.

Primary posterior capsular opacification in Indian rural population undergoing cataract surgery for hypermature senile cataract

AIM

To find out the incidence of primary posterior capsular opacification (PCO) in rural patients with a hypermature senile cataract undergoing cataract surgery.

SETTINGS

Tertiary eye care center in central India.

DESIGN

Prospective, observational, noncomparative study.

MATERIALS AND METHODS

Two-hundred eyes of 200 patients presenting with a hypermature cataract underwent manual small incision cataract surgery. A single surgeon performed all surgeries under peribulbar anesthesia. After cortical clean-up, the capsular bag was inflated with viscoelastic. The presence or absence of opacity on the posterior lens capsule and location was noted. Postoperative follow-up was done for visual acuity and need for neodymium-doped yttrium aluminum garnet (ND:YAG) laser capsulotomy.

RESULTS

Primary PCO occurred in 76 eyes (incidence of 38%). It was peripheral in 58 eyes (76.3%) and central in 18 eyes (23.7%). At 6 weeks postoperatively, best corrected visual acuity for eyes with central primary PCO (n = 18) was 0.2-0.3 logMAR and 0-0.2 logMAR for eyes with peripheral primary PCO (n = 58). Best corrected visual acuity at the 6- and 12-month follow-up was 0-0.2 logMAR in both groups. Fibrotic primary PCO was seen in four patients. No predilection for the development of primary PCO to a particular quadrant of posterior capsule was observed. At 1 year postoperatively, eleven (14.5%) patients required ND:YAG laser capsulotomy, six (7.90%) of whom underwent ND:YAG laser capsulotomy at the 6-month follow-up. Seven patients with central primary PCO and four patients with peripheral primary PCO required ND:YAG laser capsulotomy.

CONCLUSION

A high incidence of primary PCO was noted in rural patients with a hypermature senile cataract undergoing cataract surgery. No serious intraoperative complications were noted. Visual outcome at 1-year follow-up was satisfactory. Need for early ND:YAG laser posterior capsulotomy should be explained to these patients before cataract surgery. No post ND:YAG capsulotomy complications were noted in any patient.

Application of sustained delivery microsphere of cyclosporine A for preventing posterior capsular opacification in rabbits

AIM

To explore the inhibitory effect of a sustained cyclosporin A (CsA) delivery microsphere (CsA-MS) on posterior capsular opacification (PCO) in rabbit eyes after cataract extraction.

METHODS

Twenty New Zealand white rabbits accepted cataract extraction plus intraocular lens implantation and their left eyes were intraoperatively injected CsA-MS prepared using polymer polylactioglycolic acid (PLGA) as a carrier and their right eyes were injected with empty MS. The changes in cornea, anterior chamber reaction, intraocular pressure, PCO and CsA concentration in aqueous humor were examined postoperatively and all the eyes were enucleated 3 months after surgery for histopathological and morphological examination with light microscopy and electron microscopy.

RESULTS

Conjunctival hyperemia, corneal edema, intraocular pressure and anterior chamber response of experimental and control eyes were similar, while PCO in CsA-MS injected eyes was greatly improved compared with that in control eyes. Posterior capsules in CsA-MS injected eyes were smooth and lens epithelial cells (LEC) did not proliferate significantly (P>0.05), while LEC in posterior capsule of control eyes had different degrees of proliferation and cortical regeneration. LEC in CsA-MS injected eyes were not functionally active and underwent apoptosis, whereas LEC in control eyes were functionally active (F-test, P=0.025). In addition, the corneal ultrastructure showed no differences between CsA-MS and MS injected eyes.

CONCLUSION

CsA-MS has high bioavailability in rabbit eyes and could inhibit postoperative PCO occurrence and development during the study period, suggesting that CsA-MS may be a promising, effective and safe administration route to prevent PCO in clinic.

Comparison of design of intraocular lens versus the material for PCO prevention

AIM

To evaluate the influence of different intraocular lens(IOL) designs made of PMMA on posterior capsular opacification(PCO) and compare with foldable designs.

METHODS

Phacoemulsification and IOL implantation was done in one eye of 24 New Zealand White rabbits, with IOL of two different designs (Square edged or round edge) and two different materials(PMMA or HEMA). After three months, the animals were sacrificed and enucleated. Evaluation of PCO included posterior view, migration of anterior capsular epithelial cells to the posterior capsule following epithelial-mesenchymal transition were assessed by staining the histological sections of posterior capsule by hematoxylin-eosin(HE) and Periodic acid- Schiff (PAS). The IOLs were extracted and stained with HE to evaluate the presence of adherent cells on the lens surface.

RESULTS

PCO was highest with round edged rigid lens. There was no significant difference in the PCO between the square edged PMMA and square edged foldable lens.

CONCLUSION

It is the design of the IOL not the material that offers protection on PCO formation.

Use of topical brimonidine to prevent intraocular pressure elevations following Nd: YAG-laser posterior capsulotomy

Objective:

To study the effect of brimonidine on intraocular pressure (IOP) following capsulotomy among Indian subjects.

Materials and Methods:

The study was a nonrandomized trial with open label.

Results:

80% of the subjects showed a decrease in IOP after instilling 0.2% brimonidine (1 hour pre capsulotomy). No such decrease was observed in control. After 1 and 4 h post capsulotomy a statistically significant decrease in IOP ranging between 1–10 mmHg was found in 73.3% of the treatment group.

Conclusions:

In the present study 0.2% brimonidine has been proven effective to counteract the increase in IOP following Nd-YAG laser capsulotomy in Indian setting.