Posterior Capsule Opacification With Two Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

Long-Term Clarity of High-Water-Content Hydrophobic Acrylic Intraocular Lens: A 3-Year Randomized Comparison with a Hydrophobic Lens of Similar Material and Design

INTRODUCTION

This randomized prospective study aimed to quantitatively evaluate 3-year visual function, glistenings, and surface light scattering following the implantation of high-water-content hydrophobic acrylic intraocular lenses (IOLs).

METHODS

One-piece high-water-content IOLs (Clareon® SY60WF; group C) and control hydrophobic acrylic IOLs (Vivinex XY1; group V) were randomly implanted in 120 Japanese participants (120 eyes). Subsequently, the corrected distance visual acuity (CDVA), contrast sensitivity, glistening-derived microvacuoles (MVs), and surface light scattering were examined up to 3 years postoperatively. EPCO software was used to confirm the absence of postoperative capsule opacification to ensure that it did not influence the outcomes. MVs within a 15 × 4 mm area were counted using a slit-lamp microscope. Surface light scattering was evaluated using densitometry. Finally, outcomes were compared among the groups.

RESULTS

Overall, 116 eyes were compared (58 eyes each in groups C and V). No differences in the CDVA, contrast sensitivity, and MVs were observed between the groups. The mean densitometry value in group C was significantly higher (P = 0.027) than in group V, increasing significantly from the values recorded at 1-4 weeks, although the change was clinically small (0.29%).

CONCLUSION

This randomized comparative study confirmed non-inferiority in visual function of eyes with Clareon IOLs. A 3-year comparison indicated no difference in glistening suppression, CDVA, or contrast sensitivity, whereas a slight increase was observed in surface light scattering.

TRIAL REGISTRATION

Registered in the Japan Registry for Clinical Trials (identifier jRCTs032190093).

Comparison of Visual Acuity Outcomes of Enhanced Monofocal Versus Standard Monofocal Intraocular Lenses from a Randomized, Multicenter, Active-Controlled Trial

PURPOSE

To compare visual performance of the Vivinex Impress enhanced monofocal intraocular lens (IOL) (HOYA Surgical Optics) with the Acrysof IQ monofocal IOL (Alcon Laboratories, Inc).

METHODS

In this multicenter, active-controlled trial, participants were randomized 2:1 to bilateral implantation with the enhanced monofocal (test) or standard monofocal (control) IOL and examined through 12 months postoperatively for visual acuities, refractive outcomes, defocus curves, and pupil diameters.

RESULTS

Ninety-eight test and 46 control participants completed testing for the first implanted eye. The test arm demonstrated a statistically significant benefit in monocular distance-corrected intermediate visual acuity (DCIVA) (photopic: 1.2 lines, P < .001; mesopic: 0.7 lines, P = .01) and uncorrected intermediate visual acuity (0.8 lines; P < .001) but no significant difference in monocular corrected distance visual acuity (P = .07). Using a stepwise regression analysis for DCIVA, the final model (adjusted R-square, 0.31) identified three significant predictor variables (age, pupil diameter, and treatment arm). Photopic defocus curves showed the test arm produced better monocular visual acuity from -1.00 through -2.50 D than the control arm. The intermediate vision benefit of the test IOL is independent of pupil size and axial length. Cumulative and persistent adverse events for the test IOL did not exceed the Safety and Performance Endpoint rates per International Organization for Standardization 11979-7.

CONCLUSIONS

Compared to a standard monofocal IOL, the Vivinex Impress enhanced monofocal IOL offers an extended range of vision, with significant improvements in intermediate vision and a DCIVA benefit unaffected by pupil size and axial length. This IOL is safe and effective for patients seeking improved intermediate vision following cataract surgery. [J Refract Surg. 2025;41(4):e300-e309.].

Effect of factors on the space between the posterior capsule and IOL

OBJECTIVES

To evaluate the effect of factors on the space between the posterior capsule and IOL.

METHODS

A total of 126 patients were included in the study. All patients underwent AS-OCT examinations after surgery. The relationship between the posterior capsule-IOL (PC-IOL) adhesion range and various factors, including IOL type, follow-up period, axial length, and lens thickness, were analyzed.

RESULTS

When the follow-up period was shorter than 1 week, the proportion of PC-IOL adhesion range greater than 1/2 in the ZA9003, softec, SN6ATX, and 525 groups was 66.7%, 78.9%, 25%, and 53.8%, respectively. When the follow-up period was longer than 1 month, these proportions increased to 75%, 100%, 40.8%, and 100%, respectively. In the multivariate logistic regression analysis, only the IOL types and follow-up period were statistically significant, while axial length and lens thickness were not statistically significant.

CONCLUSION

The follow-up period and IOL types affect the space between the IOL and the posterior capsule, whereas axial length and lens thickness do not. Among the four IOL types studied, the softec IOL has the strongest adhesive power, while the SN6ATX IOL has the weakest.

Pseudophakic cystoid macular oedema and posterior capsular opacification rates after combined phaco-trabeculectomy vs. phaco alone

PURPOSE

To assess the risk for pseudophakic cystoid macular oedema (PCME) and posterior capsular opacification (PCO) associated with combined cataract surgery and trabeculectomy compared to cataract surgery alone.

METHODS

Data analysis of subjects who underwent routine cataract surgery without and with concomitant trabeculectomy at the Department of Ophthalmology, Bristol Eye Hospital, the UK, between January 2008 and December 2017. Odds ratios (ORs) for PCME between the types of surgeries were calculated using univariate and multivariate regression analysis. Multivariate Cox regression controlling for age and gender was used to estimate the hazard ratio (HR) for neodymium-doped yttrium aluminium garnet (Nd:YAG) laser capsulotomies.

RESULTS

This study included 56 973 cataract surgeries without and 288 with concomitant trabeculectomy (phaco-trab) with a mean follow-up time of 6.9 ± 4.2 years. Baseline variables (age and gender, diabetes, pseudoexfoliation, use of pupil expansion device and postoperative follow-up time) were comparable between the groups. Postoperative rates of PCME remained non-significant between the cataract surgery and phaco-trabe groups both in uni- and multi-variate analysis (OR 0.347, 95%CI 0.049-2.477, p = 0.291). Furthermore, in Cox regression analysis adjusted for the patients' age and gender, Nd:YAG laser capsulotomy rates remained non-significant between the cataract surgery and phaco-trabe groups (HR 1.250, 95%CI 0.883-1.769, p = 0.209).

CONCLUSIONS

In our large cohort study, combining trabeculectomy with cataract surgery did not predispose to an increased PCME or Nd:YAG laser capsulotomy rates.

Examining Penetration and Residual Depth in Modern Acrylic Foldable Intraocular Lenses: A Laboratory Study Using Differential Interference Contrast Microscopy to Compare Hydrophilic and Hydrophobic Materials

Introduction The material of modern intraocular lenses must meet the highest standards and fulfill various requirements. It is crucial that the material shows the best biocompatibility and should be flexible for an uncomplicated implantation process through small corneal incisions but also sufficiently rigid for good stability and centering in the capsular bag. In addition, the optic must remain clear for life and retain the best optical properties. Methods In this laboratory experiment, we performed scratch tests for the mechanical assessment of acrylic intraocular lenses. The aim was to determine differences in the behavior in regard to the manufacturing process and water content of hydrophilic and hydrophobic acrylic intraocular lenses. The scratch tests were performed using a Nano Scratch Tester. A conical indenter with a tip radius of 1 µm and a cone angle of 90° was selected to scratch the samples at three different constant loads of 5, 10, and 15 mN, respectively. The scratch length was set to 100 µm at a scratch speed of 200 µm/min. Hydrophilic and hydrophobic acrylic intraocular lenses (with different water content) were tested. Results The results showed that for sample A (hydrophilic acrylate), the penetration depth increases steadily with increasing force from 25-30 µm (5 mN) to 28-33 µm (10 mN) and 34-37 µm (15 mN). The penetration depths during the scratches seem to be load-dependent. In sample B (hydrophobic acrylate), the same forces lead to steadily increasing penetration depths: 25-30 µm (5 mN), 40-44 µm (10 mN), and 54-57 µm (15 mN). The evaluation of the residual depth showed much lower values for all samples. In the hydrophilic, softer samples (A), the residual depth was between 1 µm and 4 µm. In the hydrophobic, more solid, samples (B), the residual depth was more pronounced with values between 5 µm and 17 µm. The plastic influence and deformation zone seemed to be wider for the hydrophobic samples than for the hydrophilic samples. Conclusion The laboratory experiment confirms that modern, acrylic intraocular lenses are sensitive to scratches/touch, and penetration depths during scratching depend on the load. The remaining depths after the scratches are significantly lower and show a load dependence. The deforming zone was higher in the hydrophobic acrylates than in the hydrophilic acrylates. However, the results confirm that damage can occur with hydrophobic and hydrophilic acrylic materials, depending on the force applied. Therefore, careful handling during the preparation and implantation process is crucial to prevent permanent defects.

Recurrent Posterior Capsular Opacification in Adults: A Case Report and an Overview of Literature

Posterior capsular opacification (PCO), also known as "secondary cataract", is a common complication following cataract surgery that can significantly impair visual acuity. The incidence of PCO varies widely in the literature, influenced by intraocular lens (IOL) type and patient risk factors. Neodymium-doped yttrium-aluminum-garnet (YAG) laser posterior capsulotomy is the standard treatment for PCO-related visual impairment. Recurrence of PCO after initial treatment with YAG capsulotomy, though more common in children, is rare in adults. Its underlying pathophysiological mechanisms are similar to that of primary PCO, which includes proliferation, migration, and/or clustering of lens epithelial cells (LECs), with subsequent reclosure of the posterior aperture. Potential risk factors for PCO recurrence that have been speculated through a comprehensive search of the current literature include younger age, female sex, high myopia, diabetes, vitrectomized status, uveitis, low-diopter IOLs, and certain IOL types with higher water content. We present a case of recurrent PCO in a highly myopic 48-year-old male following cataract surgery and implantable collamer lens (ICL) explantation who received a hydrophobic acrylic lens with 4% water content. Surgical techniques that may reduce recurrent PCO occurrence and appropriate postoperative care are emphasized to assist surgeons in their approach to patients at high-risk for this complication.

Clinical outcomes and rotational stability after implantation of a monofocal toric intraocular lens with textured haptics in normal vs high axial lengths

PURPOSE

To compare the clinical outcomes and rotational stability after implantation of a toric intraocular lens (IOL) with textured haptics in eyes with normal vs high axial lengths (ALs).

SETTING

Nethradhama Superspeciality Eye Hospital, Bangalore, India.

DESIGN

2-arm, retrospective comparative study.

METHODS

This retrospective study included 114 eyes of 114 patients who underwent femtolaser cataract surgery followed by implantation of the HOYA Vivinex Toric monofocal IOL (Model XY1A-SP), of which 62 and 52 eyes belonged to normal (≤23.9 mm) and high (≥24 mm) AL groups, respectively. 1 week and 3 months postoperatively, clinical outcomes and rotational stability of the toric IOL was evaluated.

RESULTS

3 months postoperatively, % eyes achieving refractive astigmatism accuracy within ≤0.50 diopter, was 100% (n = 62) in the normal vs 94% (n = 49) in the high AL group. All eyes that is, 100% (n = 62) in the normal and 96.15% (n = 50) eyes in the high myopia group were <5 degrees of the intended axis. The mean change in postoperative rotation from 1 week to 3 months was 0.28 ± 0.09 degrees in the normal, and 0.30 ± 1.11 degrees in the high AL group ( P = .80). No significant correlation was observed between AL and white-to-white diameter with 1-week postoperative rotation values. No eye required repositioning of toric IOL for significant misalignment.

CONCLUSIONS

No significant differences were observed for clinical outcomes and postoperative rotational stability between eyes with normal and high ALs, suggesting excellent rotational stability of the Vivinex Toric IOL with textured haptics in all eyes, irrespective of the preoperative AL measurements.

Effect of surface-modified intraocular lenses on long-term postoperative inhibition of posterior capsule opacification

We compared the posterior capsule opacification incidences at 5 years postoperatively and the neodymium-yttrium-aluminum-garnet capsulotomy rates at 10 years postoperatively for two types of intraocular lenses with different optical properties and shapes. This randomized, controlled, prospective, single-blinded study with intra-individual comparisons was conducted between July 21, 2009, and August 31, 2011, at the Dokkyo Medical University Hospital, Tochigi, Japan. Thirty patients (60 eyes) underwent bilateral cataract surgery and received a XY1 intraocular lens in one eye and a FY-60AD intraocular lens in the other. Both intraocular lenses are acrylic and manufactured by HOYA. The XY1 lens is a single-piece, tinted intraocular lens featuring an ultraviolet/ozone treatment on the posterior surface of the lens optic, aimed at enhancing posterior capsule adhesion to prevent posterior capsule opacification. Conversely, the FY-60AD is a tinted intraocular lens with modified polymethylmethacrylate C-loops and no ultraviolet/ozone treatment of the optic. Scheimpflug images were taken using EAS-1000 (NIDEK Co., Ltd., Aichi, Japan), and the scattered light intensity (computer compatible tape) on the posterior surface of the intraocular lens was calculated and evaluated as the posterior capsule opacification. The scattered light values of the XY1 and FY-60AD groups were 6.50 ± 5.69 and 11.64 ± 5.30 computer compatible tape, respectively, at 5 years postoperatively. The cumulative survival incidence after neodymium-yttrium-aluminum-garnet laser capsulotomy was 74.8 % in the XY1 group and 13.8 % in the FY-60AD group at 10 years postoperatively. The surface-modified intraocular lens XY1 reduced the incidence of posterior capsule opacification even 10 years after surgery. Surface modification to increase the adhesion between the intraocular lens and the capsule effectively prevents posterior capsule opacification.

Intraocular lens selection in diabetic patients: How to increase the odds for success

The incidence of cataracts is significantly higher in diabetic individuals, particularly in younger age groups, with rates quadrupled in those under 65 and doubled in those over 65 compared to non-diabetics. Cataract surgery in diabetic patients poses many challenges: Poor epithelial healing, decreased corneal sensitivity, increased central corneal thickness, decreased endothelial cell count, variable topography, poor pupillary dilatation, anterior capsular phimosis, posterior capsular opacification (PCO), chances of progression of diabetic retinopathy (DR), zonular weakness, and vitreous prolapse and diabetic macular edema. Selection of an appropriate intraocular lens (IOL) is crucial for visual rehabilitation and monitoring DR. The choice of IOL in diabetic cataract patients is a challenging scenario. Square-edge IOLs are favored for their capacity to mitigate PCO, whereas hydrophilic counterparts may incur calcification in the setting of proliferative DR. The advisability of premium IOLs for achieving spectacle independence warrants judicious evaluation, particularly in the presence of advanced retinopathy. Optimal IOL placement within the capsular bag is advocated to minimize postoperative complications. Rigorous preoperative assessment and informed patient counseling regarding IOL options are indispensable for optimizing surgical outcomes. This review article covers various aspects regarding the choice of IOLs in different case scenarios and complications in the diabetic population.

Customizing Clinical Outcomes with Implantation of Two Diffractive Trifocal IOLs of Identical Design but Differing Light Distributions to the Far, Intermediate and Near Foci

Purpose

To evaluate clinical outcomes after bilateral or contralateral implantation of the Gemetric™ (G) and Gemetric™ Plus (GPlus) diffractive trifocal intraocular lenses (IOLs).

Methods

This was a prospective, randomized, multi-center open-label study comparing clinical results and subjective patient responses around 6 months after implantation of the study lenses (toric and non-toric) in three different groups (bilateral G, bilateral GPlus and contralateral G/GPlus implantation). Results included the manifest refraction, uncorrected and distance corrected monocular and binocular visual acuity (VA) at distance, intermediate and near; the defocus curve; contrast sensitivity; and patient reported outcomes regarding spectacle independence, satisfaction and visual disturbances.

Results

There was no statistically significant difference in the mean refraction spherical equivalent between the two lens models (p = 0.33) or between the toric and non-toric lenses (p = 0.06). Monocular VA was better at distance with the G lens and better at near with the GPlus lens (p < 0.01). Mean binocular VA was better than 0.1 logMAR at all distances for all groups, both uncorrected and distance corrected. The mean binocular distance corrected VA was better than 0.15 logMAR from 0.0 D to -3.50 D for all groups. All VA data for the contralateral group was as good or better than for the bilateral GPlus group. Questionnaire results showed no difference between groups for the frequency, severity, or degree of bother of visual disturbances (p > 0.24).

Conclusion

The two diffractive trifocal IOLs studied here may be used either bilaterally or contralaterally for the correction of presbyopia in cataract patients, providing excellent visual acuity with low levels of visual disturbances and high rates of overall spectacle independence. Bilateral Gemetric implantation resulted in slightly better distance and intermediate vision while contralateral implantation provided slightly better near vision. There was no apparent advantage to implanting the GPlus IOL bilaterally.

Comparison of the Incidence of Nd:YAG Laser Capsulotomy Based on the Type of Intraocular Lens

Background and Objectives: Posterior capsular opacification (PCO) is the most common long-term complication of successful cataract surgery and can cause visual impairment. We aimed to investigate the effects of intraocular lens (IOL) characteristics on PCO by comparing the incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy for different types of intraocular lenses. Materials and Methods: A retrospective analysis was performed on 2866 eyes that underwent cataract surgery between January 2010 and December 2017, with at least 5 years of follow-up. The IOLs used for surgery were the hydrophobic lenses SN60WF (Alcon, Fort Worth, TX, USA), ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA), and MX60 (Bausch & Lomb, Rochester, NY, USA), and the hydrophilic lens MI60 (Bausch & Lomb, Rochester, NY, USA). We analyzed the incidence of Nd:YAG laser capsulotomy according to the type of IOL used. Results: The incidence of Nd:YAG laser capsulotomy was significantly higher with MI60 lenses (31.70%, 175/552 eyes) compared to SN60WF (7.90%, 113/1431 eyes), ZCB00 (10.06%, 64/636 eyes), and MX60 (10.57%, 13/123 eyes; p < 0.001) lenses. The incidence of Nd:YAG laser capsulotomy was significantly lower with the hydrophobic IOLs (8.68%, 190/2190 eyes) than with the hydrophilic IOL (31.70%, 175/552 eyes; p < 0.001). Over time, the rate of increase in the cumulative number of Nd:YAG laser capsulotomy cases was the highest with MI60. The cumulative rate of Nd:YAG laser capsulotomy during the first 3 years was 4.90% with SN60WF (70/1431 eyes), 6.76% with ZCB00 (43/636 eyes), 8.94% with MX60 (11/123 eyes), and 26.10% with MI60 (144/552 eyes) lenses. Conclusions: The incidence of PCO is influenced by the material of the IOLs. The hydrophilic IOL was associated with a higher rate of Nd:YAG laser capsulotomy than the hydrophobic IOLs, with a shorter time to Nd:YAG laser capsulotomy.

Comparison of the Rate of Posterior Capsule Opacification Following Combined Treatment With Topical Dexamethasone 0.1% Plus Ketorolac 0.5% Eye Drops Versus Dexamethasone 0.1% Alone: A Two-Year, Randomized Clinical Investigation

Background and aim The use of non-steroidal anti-inflammatory drugs in animals decreases the incidence of posterior capsular opacification (PCO) following cataract surgery. We evaluated the rate of PCO in patients with cataract surgery and foldable "in the bag" posterior chamber intraocular lens (PC-IOL) implantation treated with combined dexamethasone 0.1% plus ketorolac tromethamine 0.5% versus dexamethasone 0.1% alone. Materials and methods A total of 114 eyes of 101 patients underwent uneventful corneal small-incision phacoemulsification with primary implantation of a foldable acrylic PC-IOL (AcrySof^®, Alcon, Fort Worth, USA). Postoperatively for four weeks, group 1 eyes were treated with dexamethasone 0.1% plus ketorolac tromethamine 0.5% ophthalmic solutions four times daily for each whereas group 2 eyes were treated with dexamethasone 0.1% alone. Other regiments were the same for each group. Patients were evaluated between one- and four-year following surgery. The frequency and timing of severe PCO following surgery that needed Nd:YAG laser posterior capsulotomy were recorded and evaluated. Results The mean (SEM) age of group 1 (n = 54) and group 2 (n = 60) at operation was similar (62.8 ± 2.2 vs. 60.6 ± 1.7 years, respectively). Eighty-eight patients had unilateral cataract and 13 cases had bilateral disease. Overall, the mean follow-up duration was 24.7 months postoperatively (range, 15-48). Clinically significant PCO that finally needed Nd:YAG laser application developed in two eyes (3.7%) in group 1 and in four eyes (6.6%) in group 2, and the difference was not statistically significant (p>0.05). The mean month at capsulotomy was 26.5 in group 1 and 24.3 months in group 2 eyes (p>0.05). Conclusions Topical instillation of ketorolac ophthalmic solution in the immediate period after phacoemulsification and PC-IOL implantation did not seem to influence the incidence of PCO formation two years after cataract surgery.

Nd:YAG laser capsulotomy rates in the Netherlands: practice variation and association with physician practice styles

PURPOSE

To determine the practice variation in the rate of Nd:YAG laser capsulotomy within 1 year after cataract surgery and to identify possible associations with physician practice styles.

SETTING

All hospitals and private clinics in the Netherlands.

DESIGN

Retrospective observational study.

METHODS

In the national medical claims database, we identified all laser capsulotomies performed in the Netherlands within a year after cataract surgery in the years 2016 and 2017. Centers with the lowest and highest percentages of Nd:YAG laser capsulotomies were interviewed on their physician practice styles related to the development of posterior capsule opacification.

RESULTS

The incidence of Nd:YAG laser capsulotomy varied between 1.2% and 26.0% in 2016 (median 5.0%) and between 0.9% and 22.7% in 2017 (median 5.0%). The rate of capsulotomy was highly consistent over time for each center (Pearson correlation coefficient, 0.89, P < .001). In general, ophthalmology centers with a high rate of Nd:YAG laser capsulotomy more often did not (routinely) polish the posterior lens capsule, performed cortex removal with coaxial irrigation/aspiration (I/A, instead of bimanual), and more often used hydrophilic intraocular lenses (IOLs) (compared with only using hydrophobic IOLs).

CONCLUSIONS

We found a significant practice variation in performing Nd:YAG laser capsulotomy within 1 year after cataract surgery in the Netherlands. Routinely polishing the posterior capsule, using bimanual I/A, and the use of hydrophobic IOLs are associated with a lower incidence in Nd:YAG laser capsulotomy. Incorporating these practice styles may lower the practice variation and thus prevent added medical burden for the patient and decrease costs.

Inhibition of posterior capsule opacification by adenovirus-mediated delivery of short hairpin RNAs targeting TERT in a rabbit model

PURPOSE

Posterior capsule opacification (PCO) is the most common postoperative complication after cataract surgery and cannot yet be eliminated. Here, we investigated the inhibitory effects of telomerase reverse transcriptase (TERT) gene silencing on PCO in a rabbit model.

METHODS

After rabbit lens epithelial cells (LECs) were treated with adenovirus containing short hairpin RNAs (shRNA) targeting TERT (shTERT group), adenovirus containing scramble nonsense control shRNA (shNC group) or PBS (control group), quantitative real-time polymerase chain reaction and Western blotting were used to measure the expression levels of TERT, and a scratch assay was performed to assess the LEC migration. New Zealand white rabbits underwent sham cataract surgery followed by an injection of adenovirus carrying shTERT into their capsule bag. The intraocular pressure and anterior segment inflammation were evaluated on certain days, and EMT markers (α-SMA and E-cadherin) were evaluated by Western blotting and immunofluorescence. The telomerase activity of the capsule bag was detected by ELISA. At 28 days postoperatively, haematoxylin and eosin staining of the cornea and iris and electron microscopy of the posterior capsule were performed.

RESULTS

Application of shTERT to LECs downregulated the expression levels of TERT mRNA and protein. The scratch assay results showed a decrease in the migration of LECs in the shTERT group. In vivo, shTERT decreased PCO formation after cataract surgery in rabbits and downregulated the expression of EMT markers, as determined by Western blotting and immunofluorescence. In addition, telomerase activity was suppressed in the capsule bag. Despite slight inflammation in the iris, histologic results revealed no toxic effects in the cornea and iris.

CONCLUSION

TERT silencing effectively reduces the migration and proliferation of LECs and the formation of PCO. Our findings suggest that TERT silencing may be a potential preventive strategy for PCO.

Randomized multicenter trial to assess posterior capsule opacification and glistenings in two hydrophobic acrylic intraocular lenses

To evaluate the long-term posterior capsule opacification (PCO) formation, and glistening rate of the HOYA Vivinex (XY1) IOL compared to Alcon AcrySof (SN60WF). In this prospective, multicentric, randomized, paired-eye, open-label study, we included 87 subjects that underwent cataract surgery with IOL implantation, with 67 patients completing the 3-year follow-up. The completer population consisted of 32 subjects implanted with XY1 and 35 implanted with SN60WF. Primary endpoints consisted of the evaluation of glistenings and measurement of PCO. Secondary outcomes included Best Corrected Distance Visual Acuity (BCVA), Contrast Acuity (CA), uncorrected visual acuities, subjective refraction, medical and lens complication rates, adverse events, and optical/visual symptoms. Follow-up visits occurred at 6-months, 1-, 2- and 3-years. At 3-years follow-up, mean PCO score was 0.121 ± 0.193 for eyes implanted with Vivinex versus 0.239 ± 0.463 for AcrySof (p = 0.026). The Vivinex IOL showed statistically significantly lower glistening occurrence through 3-years postoperatively (0.14 ± 0.26) compared to AcrySof (1.79 ± 1.43; p < 0.0001). Postoperative visual acuities improved from baseline in both IOL groups (p < 0.0001), and remained stable through the 3-year follow-up period. Eyes implanted with a HOYA Vivinex IOL exhibited significantly lower occurrence of glistening at 3-years versus Alcon AcrySof (p < 0.0001). Incidence of PCO was very low and comparable in both Vivinex and AcrySof eyes.

Micro-Computed Tomography (µCT) as a Tool for High-Resolution 3D Imaging and Analysis of Intraocular Lenses: Feasibility and Proof of the Methodology to Evaluate YAG Pits

INTRODUCTION

Posterior capsule opacification (PCO) is the most frequent late sequelae after successful cataract surgery. Neodymium:yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered the gold standard and a well-accepted, safe, and effective measure in treating PCO. However, iatrogenic damage of the intraocular lens (IOL) due to inappropriate focusing is a quite common side effect. These permanent defects (YAG pits) can critically affect overall optical quality.

METHODS

In this laboratory study, we used the micro-computed tomography (µCT) technique to obtain high-resolution 3D images of the lens and the YAG pits.

RESULTS

To the best of our knowledge, this is the first description of a detailed analysis of IOLs with µCT technology. This non-destructive technique seems to be ideal for comparative studies, measuring dimensions of the damage, and visualizing shooting channels within the material.

CONCLUSION

µCT is excellently suited to examine an IOL in detail, analyze optics and haptics in three dimensions, and to describe all kinds of changes within the IOL without damaging it.

Two-dimensional ultrathin Ti3C2 MXene nanosheets coated intraocular lens for synergistic photothermal and NIR-controllable rapamycin releasing therapy against posterior capsule opacification

Posterior capsule opacification (PCO) is one of the most frequent late-onset complications after cataract surgery. Several kinds of drug-eluting intraocular lenses (IOL) were designed for sustainable drug release to suppress ocular inflammation, the proliferation of lens epithelial cells (LECs) and the development of PCO after cataract surgery. Despite previous advances in this field, the drug-loaded IOLs were limited in ocular toxicity, insufficient drug-loading capacity, and short release time. To prevent PCO and to address these drawbacks, a novel drug-loaded IOL (Rapa@Ti3C2-IOL), prepared from two-dimensional ultrathin Ti3C2 MXene nanosheets and rapamycin (Rapa), was fabricated with a two-step spin coating method in this study. Rapa@Ti3C2 was prepared via electrostatic self-assembly of Ti3C2 and Rapa, with a loading capacity of Rapa at 92%. Ti3C2 was used as a drug delivery reservoir of Rapa. Rapa@Ti3C2-IOL was designed to have the synergistic photothermal and near infrared (NIR)-controllable drug release property. As a result, Rapa@Ti3C2-IOL exhibited the advantages of simple preparation, high light transmittance, excellent photothermal conversion capacity, and NIR-controllable drug release behavior. The Rapa@Ti3C2 coating effectively eliminated the LECs around Rapa@Ti3C2-IOL under a mild 808-nm NIR laser irradiation (1.0 W/cm−2). Moreover, NIR-controllable Rapa release inhibited the migration of LECs and suppressed the inflammatory response after photothermal therapy in vitro. Then, Rapa@Ti3C2-IOL was implanted into chinchilla rabbit eyes, and the effectiveness and biocompatibility to prevent PCO were evaluated for 4 weeks. The Rapa@Ti3C2-IOL implant exhibited excellent PCO prevention ability with the assistance of NIR irradiation and no obvious pathological damage was observed in surrounding healthy tissues. In summary, the present study offers a promising strategy for preventing PCO via ultrathin Ti3C2 MXene nanosheet-based IOLs with synergistic photothermal and NIR-controllable Rapa release properties.

The molecular design of performance-enhanced intraocular lens composites

Intraocular lens (IOL) implantation surgery is quite effective in the treatment of blindness caused by cataracts. However, in clinical applications, IOLs readily form glistening. This phenomenon usually occurs for a period after IOL implantation ranging from a few months to several years. The molecular mechanism of the formation of glistening in IOLs is still inconclusive. Failure to understand and explain the molecular mechanism of glistening formation greatly hinders the design and application of new glistening-free IOL materials. Here, in this study, we use molecular dynamics simulation methods to conduct in-depth research on the molecular mechanism of the glistening formation of IOLs, aiming to provide a possible molecular mechanism of glistening. Furthermore, based on this molecular mechanism, we propose a novel strategy of a glistening-free material based on a composite design method to reasonably copolymerize several types of molecules or functional groups, so that the glistening phenomenon can be effectively eliminated. The possible molecular mechanism of glistening formation proposed in this research can offer a solid theoretical basis and guidance for the subsequent construction of glistening-free IOL materials.

GSH Levels Serve As a Biological Redox Switch Regulating Sulforaphane-Induced Cell Fate in Human Lens Cells

Purpose

Sulforaphane (SFN) is a therapeutic phytochemical agent for many health conditions. SFN-induced cytotoxicity is shown to have promise in preventing posterior capsule opacification (PCO). In the current study, we aimed to elucidate key processes and mechanisms linking SFN treatment to lens cell death.

Methods

The human lens epithelial cell line FHL124 and central anterior epithelium were used as experimental models. Cell death was assessed by microscopic observation and cell damage/viability assays. Gene or protein levels were assessed by TaqMan RT-PCR or immunoblotting. Mitochondrial networks and DNA damage were assessed by immunofluorescence. Mitochondrial membrane potential, activating transcription factor 6 (ATF6) activity, ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and glutathione reductase (GR) activity were measured using different light reporter assays. SFN metabolites were analyzed by LC-MS/MS.

Results

Treatment with N-acetylcysteine (NAC), a reactive oxygen species scavenger, prevented SFN-induced cell death in both models. NAC also significantly protected FHL124 cells from SFN-induced mitochondrial dysfunctions, endoplasmic reticulum stress (ERS), DNA damage and autophagy. SFN significantly depleted GSH, the major antioxidant in the eye, and reduced GR activity, despite doubling its protein levels. The most abundant SFN conjugate detected in lens cells following SFN application was SFN-GSH. The addition of GSH protected lens cells from all SFN-induced cellular events.

Conclusions

SFN depletes GSH levels in lens cells through conjugation and inhibition of GR activity. This leads to increased reactive oxygen species and oxidative stress that trigger mitochondrial dysfunction, ERS, autophagy, and DNA damage, leading to cell death. In summary, the work presented provides a mechanistic understanding to support the therapeutic application of SFN for PCO and other disorders.

Anterior segment OCT application in quantifying posterior capsule opacification severity with varied intraocular lens designs

AIM

To evaluate the application of anterior segment-optical coherence tomography (AS-OCT) in posterior capsule opacification (PCO) severity assessment and analyse the relationship between PCO severity and intraocular lens (IOL) characters.

METHODS

PCO patients were prospectively recruited. Cross-sectional images of the anterior segment at horizontal and vertical meridians were acquired with AS-OCT. The area of the IOL-PC (posterior capsular) space and PCO severity (area, thickness, and density at 3 mm and 5 mm IOL optic regions) were measured. The relationship between PCO severity and visual acuity, comparisons of PCO severity and IOL-PC space using varied IOL designs were analysed.

RESULTS

One hundred PCO eyes were enrolled. IOL-PC space, PCO thickness and area were positively correlated with axial length. In addition, PCO area and thickness were positively correlated with visual acuity when it was ≤0.52 logMAR. The cut-off level of visual acuity should be 0.52 logMAR. With varied IOL designs, 3-piece C haptic IOL showed a smaller PCO area and thickness than the 1-piece 3 haptic IOL and 1-piece 4 haptic IOL. PCO area and thickness values for an IOL with a diameter ≤11.0 mm was greater than for an IOL with a diameter of 12.5 mm, and the differences were statistically significant. PCO area and thickness increased when IOL haptic angulation increased (from 0 to 12 degrees).

CONCLUSION

In PCO eyes, cut-off level of visual acuity is 0.52 logMAR. With more severe PCO, visual acuity maybe not enough to describe the visual function impairment. PCO severity and IOL-PC space are significantly correlated with axial length and IOL design and material.

Accuracy of the Barrett Universal II formula integrated into a commercially available optical biometer when using a preloaded single-piece intraocular lens

Purpose:

To compare the commonly used formulas for intraocular lens (IOL) selection using IOLMaster^®700 (Carl Zeiss Meditec) and to evaluate the Barrett Universal II (BU-II) formula accuracy when using the Vivinex™ iSert^® XY1 IOL (Hoya Corporation Medical Division).

Methods:

A retrospective chart review was performed that included patients who underwent uneventful cataract surgery with in-the-bag insertion of Vivinex™ iSert^® XY1 IOL. Prediction errors at 3 months postoperative of IOLMaster^® 700 with Haigis, Holladay 1, SRK/T, and BU-II formulas were compared. As a subgroup analysis, we focused on the axial length (AL) and IOL power. AL subgroup analysis was based on the following AL subgroups: short (<22.5 mm), medium (22.5–25.5 mm), and long (>25.5 mm). IOL power subgroup analysis was based on the following IOL power subgroups: low (≤18.0 diopters [D]), medium (18.5–24.0 D), and high (≥24.5 D).

Results:

This study included 590 eyes of 590 patients. Overall, the four IOL calculation formulas appeared to be similarly accurate. In the long AL subgroup, the BU-II formula had a significantly lower absolute error (AE) than the Holladay 1 formula. In the low-power subgroup, the BU-II formula had a significantly lower AE than the Holladay 1 and SRK/T formulas. On the other hand, in the high-power subgroup, the BU-II formula was significantly less accurate than the SRK/T formula and also appeared to be worse than the Holladay 1 formula (P = 0.052).

Conclusion:

The BU-II formula might be less accurate when using a Vivinex™ iSert^® XY1 IOL of 24.5 D or greater.

Comparison of Nd:YAG Laser Capsulotomy Rates Between Refractive Segmented Multifocal and Multifocal Toric Intraocular Lenses

PURPOSE

To investigate the early incidence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy according to intraocular lens (IOL) type (nontoric vs toric) and surgical techniques (femtosecond laser-assisted cataract surgery vs conventional phacoemulsification) in eyes with refractive multifocal IOLs.

DESIGN

Retrospective case-control study.

METHODS

Nine hundred thirteen eyes from 483 patients implanted with Lentis Mplus LS-313 MF20 (767 eyes) or Lentis Mplus Toric LU-313 MF20T (146 eyes) IOLs (Oculentis GmbH, Berlin, Germany) were enrolled. We compared the incidence of Nd:YAG laser capsulotomy between the nontoric and toric groups. In addition, the incidence of Nd:YAG laser capsulotomy was also evaluated according to the surgical technique used.

RESULTS

The overall incidence of Nd:YAG laser capsulotomy was 10.2% (93/913 eyes). The Nd:YAG laser capsulotomy rate was significantly higher in the toric group (24/146; 16.4%) than in the nontoric group (69/767; 9.0%; P = .007). Of the 913 enrolled eyes, 448 eyes (49.1%) underwent femtosecond laser-assisted cataract surgery and 465 eyes (50.9%) underwent conventional phacoemulsification cataract surgery. There was no significant difference in the incidence of Nd:YAG laser capsulotomy between eyes with femtosecond laser-assisted cataract surgery and eyes with conventional phacoemulsification cataract surgery.

CONCLUSION

Patients with refractive multifocal toric IOLs had higher early incidence rates of Nd:YAG laser capsulotomy when compared to those with refractive multifocal nontoric IOLs. Furthermore, femtosecond laser-assisted cataract surgery could not reduce the early incidence of Nd:YAG laser capsulotomy in this study.

A narrative review of intraocular lens opacifications: update 2020

The opacifications of intraocular lenses (IOLs) can significantly impact patients visual quality. Despite the identification of specific risk factors, manufacturing changes, opacifications are not eliminated. Likewise, more attention in recent studies was paid to possible new risk factors, however one of the most important purposes of the studies remains opacifications effect on visual performance, which could be disturbed in different aspects. The aim of this review is to discuss the main risk factors of IOLs opacification in particular IOL types, and its impact on vision quality. Different risk factors were discussed in the study, including the material of IOLs, the impact of the breakdown of blood-aqueous barrier (BAB), and certain surgeries that can be associated with opacification formation. Glistenings occur more often in a hydrophobic material, however, the changes in water content of the IOLs can significantly reduce the formation of glistenings. The studies showed a significant effect of intraocular injection of exogenous air or gas during Descemet-stripping endothelial keratoplasty, Descemet-stripping automated endothelial keratoplasty, Descemet membrane endothelial keratoplasty, and pars plana vitrectomy on calcification formation. It raises a concern, as the incidence of these surgeries is increasing. Visual acuity decreases significantly after the calcification in IOLs occurs, and it usually causes IOLs exchange. However, disability glare seems to be more affected in patients with IOLs, which were affected by glistenings than visual acuity. Disability glare is associated with increased levels of straylight, which was widely evaluated in recent studies and it was reported to be a susceptible measurement to detect the presence of IOLs pathology. For future researches, it should be noticed that disability glare and straylight are more appropriate in evaluating IOLs opacification effect on visual quality than visual acuity. While reviewing the main risk factors of IOLs opacifications particular attention must be paid on calcification occurrence in hydrophilic acrylic IOLs after surgeries with intraocular injection of exogenous air or gas.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.