Hydrophilic Acrylic Intraocular Lens Research Articles

A study of contrast sensitivity in eyes with hydrophobic and hydrophilic acrylic foldable posterior chamber intraocular lens

A study of contrast sensitivity in eyes with hydrophobic and hydrophilic acrylic foldable posterior chamber intraocular lens

A Novel 3D High Resolution Imaging Method Using Correlative X-Ray and Electron Microscopy to Study Neodymium-Doped Yttrium Aluminum Garnet Laser-Induced Defects in Intraocular Lenses.

Cataract extraction is the most frequently performed ophthalmological procedure worldwide. Posterior capsule opacification remains the most common consequence after cataract surgery and can lead to deterioration of the visual performance with cloudy, blurred vision and halo, glare effects. Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy is the gold standard treatment and a very effective, safe and fast procedure in removing the cloudy posterior capsule. Damaging the intraocular lens (IOL) during the treatment may occur due to wrong focus of the laser beam. These YAG-pits may lead to a permanent impairment of the visual quality. In an experimental study, we intentionally induced YAG pits in hydrophilic and hydrophobic acrylic IOLs using a photodisruption laser with 2.6 mJ. This experimental study established a novel 3D imaging method using correlative X-ray and scanning electron microscopy (SEM) to characterize these damages. By integrating the information obtained from both X-ray microscopy and SEM, a comprehensive picture of the materials structure and performance could be established. It could be revealed that although the exact same energies were used to all samples, the observed defects in the tested lenses showed severe differences in shape and depth. While YAG pits in hydrophilic samples range from 100 to 180 µm depth with a round shape tip, very sharp tipped defects up to 250 µm in depth were found in hydrophobic samples. In all samples, particles/fragments of the IOL material were found on the surface that were blasted out as a result of the laser shelling. Defects in hydrophilic and hydrophobic acrylic materials differ. Material particles can detach from the IOL and were found on the surface of the samples. The results of the laboratory study illustrate the importance of a precise and careful approach to Nd:YAG capsulotomy in order to avoid permanent damage to the IOL. The use of an appropriate contact glass and posterior offset setting to increase safety should be carried out routinely.

IOL exchange for positive and negative dysphotopsia

Positive and negative dysphotopsia are complaints that sometimes occur after otherwise uneventful cataract surgery with intraocular lens (IOL) implantation. In positive dysphotopsia (PD), artefacts such as glare and halos are experienced around light sources, especially in scotopic conditions. In negative dysphotopsia (ND), a dark shadow or crescent is experienced in the temporal visual field, especially in photopic conditions. An IOL‐exchange, especially with an larger sized IOL, is one of the therapies of both conditions.In this presentation, first the surgical technique to perform an IOL‐exchange will be presented. In short, the initially implanted IOL is removed through a small corneal incision (3.0 mm) after luxation of the IOL in the anterior chamber and cutting it in half before extraction. Subsequently, the new IOL is injected directly into the bag through the 3.0 mm corneal incision that was used for the removal of the initial IOL.Subsequently the clinical results of such an IOL‐exchange, with the Aspira‐aXA, a monofocal, 1‐piece hydrophilic acrylic IOL with an optic diameter of 7.0 mm, will be presented. In total, 20 eyes of 16 patients with pseudophakic dysphotopsia were included in the analysis. Nine eyes suffered from PD, ten eyes from ND, and one eye from both complaints. 15 out of 20 eyes (75%) showed complete resolution of complaints after the IOL exchange and four eyes (20%) showed a partial resolution. Postoperatively, in one eye vitreous loss occurred and resulted in cystoid macular edema, and another eye developed posterior capsular opacification, all treated successfully.As the bag‐to‐bag IOL exchange with a 7 mm IOL resulted in partial or complete resolution of positive and negative dysphotopsia in the majority of patients (95%), it is a potential treatment for patients with dysphotopsia.

Новые отечественные интраокулярные линзы. Устойчивость к процессам биодеградации в сравнении с зарубежными аналогами

Relevance. Due to the high demand for import substitution, the prospect of assessing the long-term results of implantation of domestic models of intraocular lenses (IOL) will determine their place among a wide range of models offered by modern manufacturers in our country and abroad. Purpose. To evaluate, in an in-vitro experiment on aging modeling, the resistance of new domestic IOLs to biodegradation processes in comparison with foreign analogues. Material and methods. 3 IOLs of the following models were taken: domestic IOLs made of hydrophobic acrylic: Citrine, Citrine TT, Citrine Action; domestic hydrophilic acrylic Aquamarine IOLs. Foreign hydrophobic acrylic IOLs of the AcrySof SN60AT model and hydrophilic IOLs of Rumex rAqua-4 were taken as reference. Before the experiment, the optical parameters of the studied IOLs were measured: optical power, modulation transmission function (MTF), Strel number. The induction of glistening was carried out as follows: IOLs immersed in a BSS solution were placed in an oven foR²4 hours with a temperature of 45 °С. Further, cooling was carried out to 37 °С foR².5 hours. IOL photofixation was performed at 80-fold magnification with an assessment of the degree of glistening. Optical parameters were repeatedly measured. Results. Glistening was not detected in Aquamarine IOL and Rumex rAqua-4. The 2nd and higher degree of glistening was not detected in any model of hydrophobic IOLs. The optical strength of all the studied IOLs changed in the range from 0.23 to 1.6%. MTF changes ranged from 0 to 3.7%. The number of Strel has changed in the range from 0 to 8.5%. The absence of glistening in hydrophilic IOLs can be explained by a more uniform distribution of water in the material. Differences in the degree of glistening in hydrophobic IOL models may be due to differences in production methods. The revealed changes in optical parameters are insignificant and do not exceed the limits of state standards. Conclusion. Domestic IOLs represent a worthy competition to foreign models, as they have advantages in terms of the availability of high-quality IOLs of aspherical design and a reduced degree of susceptibility to glistening. Key words: domestic intraocular lenses, hydrophobic acrylic, hydrophilic acrylic, glistening, inducing glistening, modeling of IOL aging

Results of Scanning Electron Microscopy of an Explanted Hydrophilic Acrylic IOL with Hydrophobic Coating

This article presents a clinical case of intraocular lens (IOL) removal due to surface degeneration 2 years after implantation. Explantation was performed resulting from clinically significant clouding of the IOL and decreased visual acuity. The microscopic picture and microtopography of the explanted hydrophilic acrylic IOL with hydrophobic coating were studied using scanning electron microscopy. The opacities were total, located on the entire surface of the lens, including the supporting elements.

Hydrophilic Versus Hydrophobic Acrylic Intraocular Lens Implantation in Paediatric Cataract Surgery

Introduction: The selection of intraocular lens is still debatable in paediatric eye. Due to low cost and fewer intra-operative complication hydrophilic acrylic intraocular lens are implanted in volume in low income countries. There is lack of comparative study of this type of lens with hydrophobic lens in paediatric population.
 Aims: To compare the outcomes of hydrophilic acrylic lens and hydrophobic acrylic lens in paediatric cataract surgery.
 Methods: Out of 48 eyes included in the study, the Group A (n =24) eyes were implanted with acrylic hydrophilic intraocular lens, and the Group B (n =24) were implanted with acrylic hydrophobic intraocular lens. The children were evaluated pre, intra and postoperatively for different parameter.
 Results: The mean age was 6.6±2.7 years at the time of surgery. The most common type of cataract was zonular (58% in Group A and 50% in Group B). Postoperatively, corneal edema was seen in 7(29%) eyes in group A and in 2(8%) eyes in group B. The mean follow-up was 16.9±2.9 months. At one year, the position of the intraocular lens was in the capsular bag in 20 eyes (88.33%) and 24 eyes (100 %) in the group A and B, respectively. Clear visual axis was present in 22 eyes in Group A and 24 eyes in Group B. Posterior capsule opacification occurred in 12(50%) eyes in Group A and 6(25%) eyes in Group B. Two (8.3%) eyes in group A underwent surgical membranectomy due to visual axis opacification. The mean LogMAR visual acuity was 0.56 and 0.52 in group A and B respectively at one year.
 Conclusion: Hydrophilic acrylic intraocular lens are good alternative to hydrophobic intraocular lens in Nepal in the treatment of paediatric cataract.

Stainability of Acrylic Intraocular Lens With Brilliant Blue G: An In Vitro Study

To evaluate the stainability of several acrylic intraocular lens (IOLs) with Brilliant Blue G (BBG) in vitro. Clinically relevant, laboratory, experimental study. LS313MF15 as a hydrophilic acrylic IOL and X-70, W60R, CP2.2R, YP2.2R, XC1, and XY1 as hydrophobic acrylic IOLs were included in this study. Prepared acrylic IOLs were evaluated for staining via immersion for different periods in BBG solution with adjusted concentrations. In cases where IOLs were stained blue, the sustained release of BBG and IOL cross-sectional images were evaluated, as well as changes in the optical properties of the IOLs via spectrophotometry. All acrylic IOLs were stained with BBG in a BBG concentration- and staining time-dependent manner, with almost no sustained release of BBG observed. Lenses with a higher water content exhibited more pronounced staining, and BBG penetrated into the IOLs. A decrease in light transmittance with a peak wavelength of 610 to 620 nm was observed in blue-stained IOLs. LS313MF15 was markedly blue stained even with a short period of staining. Any acrylic IOL can be stained with BBG, but hydrophilic IOLs are particularly susceptible to blue staining. Precautions should be taken in surgeries requiring the use of BBG staining, and efforts should be made to ensure that BBG components are sufficiently washed out intraoperatively.

Opacification of Hydrophilic Acrylic Intraocular Lenses: Overview of Laboratory Methods for Histological Analysis and Replication of IOL Calcification.

Opacification of intraocular lenses (IOLs) due to material changes is a serious complication that can compromise the good visual outcomes of uncomplicated cataract surgery. In hydrophobic acrylic IOLs, opacification can result from glistening formation, while in hydrophilic acrylic IOLs, there is a risk of calcification due to the formation of calcium phosphates within the polymer. Over time, various methods have been developed to investigate calcification in hydrophilic acrylic IOLs. The aim of this article is to provide an overview of standard histological staining and models used to simulate IOL calcification. Histological staining can be used to detect calcification and assess the extent of crystal formation. The development of in vivo and in vitro replication models has helped to identify the underlying pathomechanisms of calcification. In vivo models are suitable for assessing the biocompatibility of IOL materials. Bioreactors as an in vitro model can be used to investigate the kinetics of crystal formation within the polymer. The replication of IOL calcification under standardized conditions using electrophoresis allows for the comparison of different lens materials with respect to the risk of calcification. The combination of different analytical and replication methods can be used in the future to further investigate the pathomechanisms of calcium phosphate crystal formation and the influence of risk factors. This may help to prevent calcification of hydrophilic acrylic IOLs and associated explantation and complications.

Late postoperative opacification of a new type hydrophilic acrylic intraocular lens

BackgroundTo report the clinical consequences and laboratory characteristics of late postoperative opacification of a hydrophilic acrylic intraocular lens (US-860UV IOL) as well as the prognosis of IOL replacement. MethodsForty medical records (42 eyes) of patients with US-860UV IOL opacification reporting decreased or lost vision who underwent IOL explantation between 2017 and 2019 were reviewed. Explanted IOLs were analyzed by slit-lamp examination, confocal microscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) at the Shandong Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University, and Qingdao University of Science and Technology, Qingdao, China. ResultsThe mean age of the 40 patients was 74.83 ​± ​7.57 (63–92) years. The mean interval between cataract surgery and diagnosis of opacification was 32.38 ​± ​8.76 (17–48) months. Systemic diseases were found without statistical correlations, the most frequent being arterial hypertension, coronary heart disease, and diabetes mellitus. Visual acuity improved from 1.42 ​± ​1.03 to 0.31 ​± ​0.16 (logMAR) after IOL replacement. SEM, EDS and alizarin red staining showed uniformly distributed, diffuse, milk-white opacification, with calcium and phosphorus deposits on the optic and haptic surfaces that could be dissolved in 1% HCl. ConclusionsCalcium and phosphorus deposition was the main cause of hydrophilic acrylic US-860UV IOL opacification. IOL replacement can safely and effectively improve the visual acuity of patients.

Imaging Function and Relative Light Transmission of Explanted Opacified Hydrophilic Acrylic Intraocular Lenses.

We evaluated the influence of intraocular lens (IOL) opacification on the optical performance of explanted hydrophilic acrylic IOLs. We performed a laboratory analysis of 32 Lentis LS-502-1 (Oculentis GmbH, Berlin, Germany) IOLs, explanted due to opacification, in comparison with six clear unused samples of the same IOL model. Using an optical bench setup, we obtained modulation transfer function (MTF), Strehl ratio, two-dimensional MTF, and United States Air Force (USAF) chart images. In addition, we assessed light transmission through the IOLs. The MTF values of opacified IOLs at 3-mm aperture were similar to those of clear lenses, with the median (interquartile range) values of 0.74 (0.01) vs. 0.76 (0.03) at the spatial frequency of 50 line pairs per millimeter in clear and opacified IOLs, respectively. The Strehl ratio of opacified lenses was not lower than that of clear lenses. The USAF-chart analysis showed a considerable reduction in brightness in opacified IOLs. The median (interquartile range) relative light transmission of opacified IOLs in comparison to clear lenses was 55.6% (20.8%) at the aperture size of 3 mm. In conclusion, the explanted opacified IOLs had comparable MTF values to those of clear lenses but significantly reduced light transmission.

Hydrophobic surface properties of hydrophilic acrylic lenses do not protect against calcification

Opacification through calcification of hydrophilic acrylic intraocular lenses is aserious complication of cataract surgery, which usually results in explantation of the lens. In the process of calcification, the intraocular lens material plays acrucial role: calcification only occurs in hydrophilic acrylic lenses. Hydrophobic acrylic lenses show no crystal formation within the polymer. Hydrophilic acrylic lenses from some manufacturers have hydrophobic surface properties. The question arises as to what influence these surface properties have on the risk of calcification. The present study investigated whether the hydrophobic surface properties of hydrophilic acrylic lenses can prevent calcification. Using an electrophoretic in vitro model of calcification, two hydrophilic lenses with hydrophobic surface properties were compared to two hydrophilic lenses and ahydrophobic negative control to determine the risk of calcification. The lenses were then analyzed by optical microscopy, Alizarin Red and Von Kossa staining, scanning electron microscopy (SEM) and energy dispersive X‑ray spectroscopy (EDX). All four hydrophilic lens models showed calcification within the polymer. No difference was found between the hydrophilic lenses and the hydrophilic lenses with hydrophobic surface properties in terms of crystal formation. The hydrophobic negative control showed no calcification. The investigation conducted in this study under standardized conditions could show that hydrophobic surface properties of hydrophilic acrylic lenses do not protect against calcium phosphate crystal formation within the polymer. There also is arisk of calcification in these lens models.

Novel exploration of ions and fatty acids in hydrophilic acrylic intraocular lens calcification.

To conduct a novel exploration and analysis of the ion and fatty acid levels of a medium in which calcified hydrophilic intraocular lenses (IOLs) are present. Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China. Retrospective, laboratory observational case series. Eleven patients (11 eyes) who had implantation of foldable hydrogel posterior IOLs were found to have opacification of the IOLs. In vivo and in vitro analyses included the evaluation of patients' clinical characteristics, microscopy, histological staining, energy dispersive X-ray spectroscopy (EDS), the ion level of the aqueous humor (AH) and preserving fluid (PF), and the fatty acid content of AH. Ten of 11 cases were female with unilateral opacification, and seven cases had both-eye cataract surgery, including 1 first eye and 6 second eyes with IOL opacification. Four types of similar serial numbers were counted. The analysis of AH showed that the concentrations of phosphorus and silicon were elevated but that of calcium decreased, and an increased level of silicon was detected in three random PFs. The palmitic (C16:0) and stearic (C18:0) fatty acids were higher than the others in the AH. The EDS confirmed that the IOL surface deposits were composed of calcium, phosphate, and a small amount of silicon. More silicon and higher C16:0 and C18:0 were found in the AH of patients with IOL opacification. New ideas and avenues have been proposed in the study of IOL opacification.

674 Cases of Late Postoperative Intraocular Lens Opacification of a Hydrophilic-Hydrophobic Acryl Intraocular Lens in Switzerland and Retrospective Opacification Risk Factor Assessment of 212 Cases

To report the prevalence of late postoperative opacification of a hydrophilic and hydrophobic acrylic intraocular lens (IOL) and to assess the risk factors in a subset of 212 eyes of patients referred to the University Eye Department in Basel, Switzerland. Retrospective case series. A survey was performed at all large ophthalmological clinics in Switzerland regarding exchanged Lentis LS-502-1 lenses, and the number of affected eyes was counted. Moreover, consecutive patients who were referred to a tertiary clinic between September 2015 and November 2016 with Lentis LS-502-1 opacification were investigated. Peri- and postoperative charts, medical history, and topical and systemic medications were assessed. A total of 674 opacified Lentis LS-502-1 lenses have been reported in Switzerland, and 212 consecutive eyes of 182 patients were included in the study. All IOLs had a similar pattern of opacification with a yellowish, diffuse appearance, and most of them showed a small, paracentral, roundish area that was less affected or not at all. Arterial hypertension (73%), hypercholesterolemia (34%), and diabetes (21%) were the main associated systemic diseases, and statins (34%) and betablockers (34%) were the main treatments used. The prevalence of IOL opacification was 9.9%. No associated systemic eye disease or medications could be detected, which was implicated in the opacification process. The reason for opacification remains unclear, but it seems to be unrelated to the patient's state; therefore, it is attributed to primary calcification.

Post operative opacification of polymethylmethacrylate, hydrophilic and hydrophobic acrylic intraocular lenses: A retrospective observational study

: To evaluate post-operative opacification of hydrophobic, hydrophilic and polymethylmethacrylate intraocular lenses. We had performed a retrospective observational study on twenty-one patients in tertiary care hospital of North India and a private clinic from March 2020-January 2021. History of systemic diseases like diabetes mellitus, hypertension, gout, chronic obstructive pulmonary disease was noted. We had also evaluated the patients for ophthalmic conditions like recurrent uveitis, retinal surgery, paracentesis for hyphema, open globe injury repair. The diagnosis of intraocular lens opacification was made on careful slit lamp examination. The patients with severe loss of visual acuity had undergone intraocular lens exchange procedure. The explanted intraocular lenses were sent for light microscopy with special stain and scanning electron microscopy. Statistical analysis was performed using SPSS software, version 21 (SPSS, Inc.) We found that mean age of patients with intraocular lens opacification was 62.5±6.82 years. The occurrence was 16(76.19%) in hydrophilic IOL, 4(19.05%) in hydrophobic IOL and only one (4.76%) was PMMA IOL which showed that the occurrence if IOL opacification is more in hydrophilic IOL. Light microscopy and scanning electron microscopy of the explanted IOLs did not show any deposits over IOL surface. Special stains were used and it was noted that Alizarin red was positive while Von Kossa for calcium was negative. We concluded that intraocular lens opacification can occur in any type of intraocular lens, but is predominantly seen with hydrophilic acrylic intraocular lenses. Also we came to a conclusion that various ophthalmic pathologies and systemic comorbidities accelerated the process of opacification.

Evaluation of Nd:YAG laser capsulotomy results in patients who underwent cataract extraction and intraocular lens implantation with the endocapsular phacoemulsification method

Background/Aim: Posterior capsular opacification (PCO) is a common complication that develops after cataract surgery, and it can be treated neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy. In this study, we aimed to investigate the effects of different intraocular lenses (IOLs) on the development of posterior capsule opacification (PCO), to determine the time between surgery and Nd:YAG laser capsulotomy, and to evaluate the efficacy, effectiveness, and complications of capsulotomy in patients who underwent cataract surgery with the phacoemulsification method and subsequently developed PCO. Methods: The cohort study included one eye of each of 153 cases (63 males, 90 females) who underwent cataract surgery with the phacoemulsification method in our clinic from August 1, 2006, through August 1, 2008, and subsequently developed PCO. According to the type of IOL implanted, the cases were divided into three groups: polymethylmethacrylate IOL (Group 1), hydrophilic acrylic IOL (Group 2), and hydrophobic acrylic IOL (Group 3). The control examinations of the patients who underwent Nd:YAG laser capsulotomy were undertaken before capsulotomy and at the first week, first month, and third month after capsulotomy. Results: Visual acuity improvement was detected in 96.7% of the 153 cases. It was determined that 9.1% of the cases had an intraocular pressure (IOP) increase of more than 5 mmHg at the third hour after capsulotomy and approached baseline values at the end of 1 week. The mean total energy used in all the cases was 37.20 (14.70) mjl. The mean total energy used in 14 patients with an IOP elevation of above 5 mmHg was 71.07 (10.59) mjl. Nd:YAG laser capsulotomy was performed at an average of 6.29 (4.91) months in Group 1, 7.81 (4.35) months in Group 2, and 17.7 (12.35) months in Group 3. After capsulotomy, clinically significant cystoid macular edema was observed in 1.9% of the cases, IOL damage in 3.9%, and vitreous hemorrhage in 0.6%. Conclusion: In this study, the incidence of PCO development was found to be lower in the patients who underwent hydrophobic acrylic IOL implantation; therefore, this type of lens should be preferred for implantation. Although Nd:YAG laser capsulotomy is an outpatient treatment method that can be applied quickly and can increase visual acuity, it can also lead to complications. To eliminate most of these complications, it would be beneficial to minimize the energy used during the laser procedure.

Cataract surgery in patients with uveitis: Data from the Swedish National Cataract Register.

To investigate the surgical and pharmacological management and outcomes of patients with cataract and concurrent uveitis. Data from the Swedish National Cataract Register, 2018-2019, were collected and analysed. Uveitic eyes were identified and eyes without uveitis were used as controls. Generalized estimating equations were used to adjust for intra-individual correlation. The study included 719 eyes with and 256 360 without uveitis. The mean age was 66.0 ± 13.5 (standard deviation [SD]) years in the uveitis group and 74.3 ± 8.7 years in the control group (p < 0.001). Surgery was associated with more intraoperative difficulties in eyes with uveitis (27.0%) than in control eyes (7.1%; p < 0.001). Posterior capsule rupture/zonular complications were registered in nine eyes with uveitis (1.3%) and in 1464 eyes without uveitis (0.6%; p=0.02). Hydrophilic acrylic intraocular lenses (uveitis 3.6%, controls 1.2%) and subconjunctival steroids (uveitis 17.4%, controls 6.1%) were more frequently used in eyes with uveitis (p < 0.001). post-operative best-corrected visual acuity (BCVA) was 0.16 ± 0.38 logarithm of the minimum angle of resolution (logMAR, mean ± SD) in eyes with uveitis (n=52) and 0.08 ± 0.20 in control eyes (n=14 489; p=0.008). In this large registry-based Swedish cohort study, the findings demonstrate that cataract surgery in patients with uveitis poses more challenges and requires special surgical precautions. Eyes with concurrent uveitis had worse BCVA prior to and following surgery. Despite the intraoperative challenges, the visual improvement was greater in the uveitic group.

Combined Temporary Pupilloplasty and DSEK in an Eye With a Hydrophilic Acrylic Intraocular Lens to Prevent Opacification: A Case Report.

The aim of this study was to describe a case of temporary pupilloplasty during Descemet stripping endothelial keratoplasty to prevent opacification of a hydrophilic acrylic intraocular lens (IOL). A 60-year-old man presented with corneal edema in the left eye after a traumatic cataract removal and scleral suture fixation of a hydrophilic acrylic IOL (Akreos, Bausch + Lomb, Bridgewater, NJ). Descemet stripping endothelial keratoplasty with temporary pupilloplasty was performed. The pupilloplasty was lysed with neodymium:YAG laser on postoperative day 5 after the air bubble was no longer present. At 1 year after surgery, the patient did not develop IOL opacification despite the intracameral air used during the surgery. Opacification of hydrophilic acrylic lenses is a visually significant complication of intracameral gas from endothelial keratoplasty. Our case demonstrates the potential to prevent IOL opacification in a patient with a hydrophilic acrylic IOL by using temporary pupilloplasty.

Intraocular Lens Calcification After Pseudophakic Endothelial Keratoplasty

To determine the incidence and to document risk factors for intraocular lens (IOL) calcification after pseudophakic endothelial keratoplasty. We retrospectively studied 2700 consecutive penetrating, anterior lamellar and endothelial keratoplasties carried out between December 1992 and June 2022 at the National Eye Hospital, Paris, France. Retrospective cohort study. All IOL calcification cases were associated with endothelial keratoplasty. Out of 588 endothelial keratoplasty procedures, 576 eyes were pseudophakic at the end of surgery. Fourteen cases of IOL calcification were observed during follow-up. The cumulative incidence of IOL calcification after endothelial keratoplasty was 4.5%±1.3% at 60 months. Hydrophilic acrylic IOL material (P < .001) and use of SF6 for anterior chamber tamponade (P=.001) were significantly and independently associated with the cumulative incidence of IOL calcification. The incidence of IOL calcifications seems to be around 5%. Ophthalmologists should avoid hydrophilic acrylic IOLs in patients with endothelial disorders. When the patient already has a hydrophilic IOL, SF6 should be avoided. The only effective treatment is IOL exchange.

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

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

Development of a standardized in vitro model to reproduce hydrophilic acrylic intraocular lens calcification

Opacification through calcification of hydrophilic acrylic intraocular lenses (IOL) is a severe complication after cataract surgery. Causing symptoms that range from glare through to severe vision loss, the only effective therapy is explantation of the opacified IOL so far. Although IOL calcification is a well-described phenomenon, its pathogenesis is not fully understood yet. The purpose of the current study was to develop a laboratory model to replicate IOL calcification. Calcification could be reproduced using a horizontal electrophoresis and aqueous solutions of calcium chloride and disodium hydrogen phosphate. The analysis of the in vitro calcified IOLs was performed using light microscopy, Alizarin Red and Von Kossa staining, scanning electron microscopy, energy dispersive x-ray spectroscopy and electron crystallography using transmission electron microscopy and electron diffraction. The presented laboratory model could be used to identify hydrophilic IOLs that are at risk to develop calcification and to assess the influence of associated risk factors. In addition, it can serve as a research tool to further understand this pathology.