Acrylic Intraocular Lens Research Articles

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.

Accuracy of Traditional and Modern Formulas for Intraocular Lens Power Calculation After Radial Keratotomy Using Standard Keratometry.

To compare the accuracy of multiple traditional and modern intraocular lens (IOL) power calculation formulas in post-radial keratotomy (RK) patients undergoing cataract surgery. This retrospective case series included 50 eyes with prior RK who underwent routine phacoemulsification surgery with single-piece acrylic IOL implantation (A constant = 118.8). Outcomes of multiple formulas were calculated. Included formulas were SRK/T, Holladay 1, Holladay 2, Haigis, Barrett True-K, Haigis and Barrett True-K (target refraction of 0.50 D), Barrett Universal II, Kane, PEARL-DGS, Shammas no history, DK SRK/T, DK SRK/T (target refraction of 0.50 D), Double K (DK) Holladay 1, and DK Holladay 1 (target refraction of 0.50 D). Averages of multiple combinations of best-performing single formulas were calculated. Primary outcome is mean absolute error (MAE). Haigis (with -0.50 D target refraction) and DK SRK/T showed the lowest mean and median absolute errors (MedAE) followed by Haigis, Barrett True-K, and Barrett True-K (with -0.50 D target refraction). Combinations of 3, 4, or 5 of best performing single formulas yielded good results with >60% of cases within +0.50 D of intended refraction and MAE around 0.50 D. The best performing formulas with flatter K readings were PEARL-DGS and Haigis (with additional -0.50 D target refraction) with MAE of 0.72 + 0.71 D and 0.70 + 0.70 D, respectively, followed by Barrett True-K (with intended -0.50 D target refraction) with MAE of 0.75 + 0.63 D. Using an average of three or more Haigis (with -0.50 D target refraction), the Barrett True-K, DK Holladay 1, and DK SRK/T formulas showed better outcomes than using a single formula for IOLMaster 700 standard K readings. The PEARL-DGS formula showed better accuracy in eyes with flatter K readings (<38 D).

Corneal astigmatic outcomes after femtosecond laser-assisted cataract surgery combined with surface penetrating arcuate keratotomies.

To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies (FAKs) combined with femtosecond-laser assisted cataract surgery (FLACS) over 12mo follow-up. Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a single-centre, single-masked, prospective randomized controlled trial (RCT) comparing two monofocal hydrophobic acrylic intraocular lenses. Eyes with corneal astigmatism (CA) of >0.8 dioptres (D) received unpaired, unopened, surface penetrating FAKs at the time of FLACS. Visual acuity, subjective refraction and Scheimpflug tomography were recorded at 1, 6, and 12mo. Alpins vectoral analyses were performed. Fifty-one patients (61 eyes), mean age 68.2±9.6y [standard deviation (SD)], received FAKs. Sixty eyes were available for analysis, except at 12mo when 59 attended. There were no complications due to FAKs. Mean pre-operative CA was 1.13±0.20 D. There was a reduction of astigmatism at all post-operative visits (residual CA 1mo: 0.85±0.42 D, P=0.0001; 6mo: 0.86±0.35 D, P=0001; and 12mo: 0.90±0.39, P=0.0001). Alpins indices remained stable over 12mo. Overall, the cohort was under-corrected at all time points. At 12mo, 61% of eyes were within ±15 degrees of pre-operative astigmatic meridian. Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective. CA is largely under-corrected in this cohort using an existing unmodified nomogram. The effect of arcuate keratotomies on CA remained stable over 12mo.

Changes in Intraocular Lens Explantation Indications and Comparison of Various Explantation Techniques

To examine the current causes of intraocular lens (IOL) explantation, compare various IOL explantation techniques, and assess the visual outcomes and complications. Retrospective comparative case series. A total of 175 eyes of 160 patients who underwent IOL exchange for a one-piece foldable acrylic IOL between January 2010 and March 2022 were covered by the research. Group 1 included 74 eyes from 69 patients in which the IOL was removed after being grasped, pulled, and refolded inside the main incision. Group 2 consisted of 66 eyes from 60 patients in which the IOL was removed by bisecting it, whereas group 3 included 35 eyes from 31 patients in which the IOL was removed by enlarging the main incision. Surgical indications, interventions, visual outcomes and refraction, and complications. The mean patient age was 66.1 ± 10.5 years. The mean time between primary surgery and IOL explantation was 57.0 ± 38.9 months. IOL dislocation (in 85 eyes, 49.5%) was the most common reason for IOL explantation. When the patients were examined in terms of both surgical indication groups and IOL removal techniques, corrected-distance visual acuity increased significantly in all subgroups (P < .001). The increase in astigmatism after surgery was 0.08 ± 0.13 diopters (D) in group 1, 0.09 ± 0.17 D in group 2, and 0.83 ± 0.29 D in group 3 (P < .001). The grasp, pull, and refold technique for IOL explantation provides a simpler surgery, less complication, and good visual outcomes.

Scleral fixation of a novel modified, injected canine intraocular lens by haptic capture, in 17 dogs.

The aims of lens removal surgery are to re-establish or preserve both a clear visual axis and emmetropic vision. Trans-scleral intraocular lens (IOL) fixation has been described in cases where lens capsule instability precludes the insertion of a prosthetic intraocular lens into the lens capsule. Previous techniques have necessitated enlargement of the corneal incision to accommodate either a rigid polymethylmethacrylate IOL or an acrylic foldable IOL inserted using forceps. This paper reports the modification of an endocapsular IOL to be used as an injectable suture-fixated IOL introduced through a 2.8 mm corneal incision. All cases underwent lens extraction by phacoemulsification followed by removal of the unstable lens capsule. A PFI X4 IOL (Medicontur) was modified to create four open-loop haptics. The IOL was injected into the anterior chamber, each haptic was captured in a loop of suture introduced ab externo, and the lens was sutured with four-point fixation. The results from 20 eyes in 17 dogs are reported. Over an average follow-up time of 14.5 months, vision was retained in 16/20 eyes. Vision was lost in four eyes due to corneal ulceration and ocular hypertension (1/20), retinal detachment (2/20), and Progressive Retinal Atrophy (1/20). The modified PFI X4 proved suitable for injection and scleral fixation through a 2.8 mm corneal incision, with a success rate comparable to previously published techniques.

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.

Material removal mechanism in and experiments of electrorheological polishing of foldable intraocular lenses at low temperatures

The traditional method of manufacturing foldable acrylate intraocular lenses (IOLs) involves injection molding and ultraprecision diamond turning. Due to the lack of in-depth research on the material removal mechanism for soft and flexible biomaterials, traditional processing methods cannot produce high-quality surfaces of foldable IOLs. This paper presents a new manufacturing method of low-temperature-assisted electrorheological polishing to improve the surface quality of foldable IOLs. The effects of temperature on the mechanical properties, including the mean azimuth shift at the end of the molecular chain, diffusion coefficient, stress-strain response, etc., and the evolution of the material removal mechanism of abrasive particles under the electrorheological effect with temperature were systematically studied by molecular dynamics. With decreasing temperature, the mechanism of material removal from the IOL surface by abrasive particles changed from compaction removal to furrow removal, and the surface roughness decreased, which revealed that the machinability of the acrylate material could be greatly improved at low temperatures (approximately −20 °C). In addition, a new low-temperature-assisted electrorheological polishing system for IOLs was designed. An orthogonal test showed that the temperature had the most significant influence on the surface roughness, consistent with the molecular dynamics analysis results. The surface roughness of the material polished at −20 °C decreased from 491 nm to 9 nm, which indicates that low-temperature-assisted electrorheological polishing is an effective method for fabricating foldable acrylate IOLs with high efficiency and quality.

Evaluation of Visual Outcomes and 3-Month Refractive Stability of a New Hydrophobic Acrylic Intraocular Lens.

To determine the refractive stability of a new hydrophobic acrylic intraocular lens (IOL) when implanted bilaterally. This was a prospective, evaluator masked, single surgeon study of 58 eyes of 29 patients. Patients were bilaterally implanted with the Clareon monofocal IOL (CNA0T0, Alcon Vision LLC). Refractive stability was evaluated between 1 and 3 months postoperatively. At 3 months postoperatively, data were also collected for binocular uncorrected and distance corrected visual acuities at distance (4 m) and intermediate (80 cm and 66 cm) and binocular defocus curve. Postoperative refraction was statistically equivalent between 1 and 3 months postoperatively (p < 0.001). Mean postoperative uncorrected distance visual acuity was -0.01 ± 0.10 logMAR, and mean corrected distance visual acuity was -0.04 ± 0.06 logMAR. Mean postoperative uncorrected intermediate visual acuity was 0.16 ± 0.13 logMAR and 0.24 ± 0.14 logMAR at 80 cm and 66 cm, respectively. With distance correction in place, mean visual acuity at 80cm and 60cm was 0.16 ± 0.13 logMAR and 0.23 ± 0.14 logMAR, respectively. The Clareon monofocal IOL can provide stable refraction, excellent distance vision, and functional intermediate vision postoperatively.

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.

Results of Implantation of a New Hydrophobic Acrylic Monofocal Intraocular Lens in a Preloaded Injector

Purpose. To evaluate clinical and functional results of implantation of a new hydrophobic acrylic monofocal IOL in a preloaded injector.Methods. The prospective study included 60 patients (66 eyes) after Hoya iSert® 250/251 IOL implantation (31 patients, 35 eyes, group 1) and a new Hoya Vivinex Multisert® XY1-SP IOL (29 patients, 31 eyes, group 2). The mean age was 75.1 ± 7.9 years. The mean follow-up period after surgery was 3.1 ± 0.4 months. IOL viscoimplantation was performed in 100 % of cases in group 1, in group 2 — in 45.1 % of cases, and in 54.9 % — hydroimplantation was performed. Intraoperatively, the size of the corneal incision was measured with a ruler before and after IOL implantation. IOL optic power was calculated with SRK/T and Barrett Universal formulas. In the postoperative period, surgically induced astigmatism was assessed.Results. In both groups, there was a statistically significant (p &lt; 0.05) increase of UCDVA from 0.28 ± 0.09 in the preoperative period to 0.70 ± 0.17 3 months after surgery in group 1 and from 0.24 ± 0.10 in the preoperative period to 0.84 ± 0.18 3 months after surgery in group 2. Slightly lower values of UCDVA in group 1 may be associated with a higher level of SIA in this group. Similar dynamics were shown for the BCDVA (from 0.52 ± 0.21 before surgery to 0.95 ± 0.19 after 3 months of follow-up in group 1 and from 0.55 ± 0.20 before surgery to 0.98 ± 0.21 after 3 months of follow-up in group 2). No differences were found between the studied groups. After IOL implantation, there was an increase in incision size to 2.40 ± 0.12 mm in group 1 and 2.10 ± 0.08 mm in group 2 (p = 0.04). In group 1, the mean SIA after 3 months of observation was 1.10 ± 0.16 D and in group 2, 0.48 ± 0.07 D (p = 0.0007).Conclusion. This study presents the first domestic experience with the implantation of a new monofocal hydrophobic acrylic Hoya Vivinex IOL in a Multisert® preloaded injector. A comparative analysis of implantation results with monofocal Hoya 250/251 IOLs in an Isert® injector was performed. The advantage of the new IOL implantation in reducing the incidence of surgically induced astigmatism was shown.

Rotational stability of the enVista® toric lens compared to other commonly implanted toric intraocular lenses – a literature review

Preoperative corneal astigmatism higher than 1 D is present in up to 30–47% of eyes with cataracts. Proper correction of astigmatism, apart from the adequately determined spherical power of the artificial intraocular lens (IOL), is the main factor ensuring the desired result of the procedure manifested as postoperative spectacle’s independence, visual function, and as a result – patient satisfaction. Toric IOL implantation allows simultaneous cataract removal and correction of corneal astigmatism during one surgical procedure. Since the introduction of toric IOLs, more rotationally stable lenses allowing for better refractive performance have been introduced to clinical practice. EnVista® is an acrylic toric IOL (enVista® MX60T; Bausch and Lomb Inc., Rochester, NY, USA), which was introduced in 2018, and currently is one of the most used toric IOLs in clinical practice worldwide. Rotational stability, apart from adequately selected spherical and toric IOL equivalents, is the most crucial parameter determining the benefits of using a toric lens because it is estimated that for every 1° of rotation of the toric IOL from the target axis, the correction of astigmatism is reduced by 3.5%; therefore a significant change of position in the postoperative period may require another surgical intervention. In this review, based on published research, we summarized the rotational stability of the enVista® lens compared to the other toric IOLs available on the market.

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.

Scleral Suture Fixation of Dislocated Posterior Chamber Intraocular Lens: Modification for Tapered Haptics.

To present a surgical modification to a previously published technique that allows repositioning and scleral fixation of one-piece acrylic intraocular lenses with tapered haptics. A retrospective review of three consecutive cases. Our technique modification enables repositioning using scleral suture fixation of one-piece intraocular lenses with tapered haptics by looping the haptic at its proximal, notched junction to the optic with the polypropylene suture. The suture knot is internalized which effectively suspends the intraocular lens and allows for better adjustment of the intraocular lens centration. Two cases were endocapsular dislocations; the third case was dislocated extracapsularly due through a posterior capsule rupture. All showed adequate lens centration at 3 months of follow-up. One case had suffered a vitreous hemorrhage a month postoperatively that is clearing. Repositioning using scleral fixation of one-piece intraocular lenses with tapered haptics is possible with a minor technique modification. This offers an alternative to intraocular lens exchange.

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.

The Incidence of Optic Cracks or Fractures During a Foldable AcrySof or Acriva BB Acrylic Monofocal Intraocular Lens Implantation via the Manual Monarch Injector System With the Cartridge in Phacoemulsification Surgery.

To evaluate the incidence of optic cracks and/or fractures during foldable acrylic intraocular lens (IOL) implantation via the manual Monarch delivery system with the cartridge and to determine factors that help to avoid such complications. Small-incision phacoemulsification surgery was performed in 702 eyes with visually significant cataract formation. A foldable acrylic soft IOL (AcrySofâMA60BM/MA30BA, Alcon, Fort Worth, TX, USA) or a single-piece acrylic soft IOL (Acriva BBâ, VSY Biotechnology, Amsterdam, The Netherlands) was inserted in all eyes using a cartridge and viscoelastic agents (sodium hyaluronate, Healon®, Advanced Medical Optics, Santa Ana, CA, USA). Postoperative central, paracentral, or peripheral optic cracks or fractures were encountered in a total of six of 702 eyes (0.85%). Four of six lenses (0.57%) had optic cracks within the IOL substance, whereas two of 702 cases (0.28%) had full-thickness IOL fractures in the substance in multiple locations. Three of the four lenses with optic cracks were noted to be handled by tying forceps during the cartridge insertion, and one of them was the complication of holding forceps. Two IOLs with full-thickness optic fractures were encountered during the insertion of the IOLs in the capsular bag as a result of direct trauma to the lens optic by the plunger of the injector system overriding the lens optic during cartridge passage. None of the patients suffered from glare or other visual disturbances postoperatively, and, therefore, none of the six eyes required lens replacement. The unintentional extensive pressure effect of the forceps during the holding process of the IOL or the direct trauma to the lens optic by the plunger of injector systems may cause optic cracks or fractures. Physicians should continue to monitor the eyes postoperatively regularly and must determine the benefits and risks to be derived from lens replacement, if such patients complain of significant glare, image degradation, and visual disturbances. We recommend the use of preloaded lenses, which have their own delivery systems and cartridges, to minimize the risk of such complications.

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.

Posterior capsule opacification following implantation of hydrophilic compared to hydrophobic intraocular lenses

Purpose The aim of this study was to compare the onset of posterior capsule opacification (PCO) in patients who underwent hydrophilic intraocular lens (IOLs) implantation compared with hydrophobic IOL implantation. Patients and methods This is a retrospective, comparative, observational study that was conducted on patients who sought medical advice at the Ophthalmology Outpatient Clinic of the Ophthalmology Department, Ain Shams University, Cairo, Egypt, and underwent uneventful phacoemulsification cataract surgery and hydrophilic or hydrophobic acrylic nonheparinized IOL implantation. The electronic medical records were searched for surgeries performed by equal-caliber experienced surgeons. All enrolled cases underwent ‘in-the-bag’ implantation of a square-edged IOL after continuous curvilinear capsulorhexis with cortical cleanup. The evaluated data included age, sex, medical history, date of phacoemulsification cataract surgery, type of implanted IOL, and the duration till Nd : YAG capsulotomy was needed. The patients were divided into two groups: group 1 (29 eyes of 29 patients), which underwent hydrophilic acrylic IOL implantation, and group 2 (27 eyes of 27 patients), which underwent hydrophobic acrylic IOL implantation. Results There was no statistically significant difference between the hydrophilic and hydrophobic IOLs regarding the time of onset of postoperative PCO development [median=1.92 years, interquartile range=1.17–2.75 in group 1 and 1.34 years (0.5–2.41) in group 2, P=0.192). In addition, there was no statistically significant relation between the onset of PCO and the general medical condition of the enrolled patients, including diabetes mellitus, hypertension, hepatitis C virus, renal disease, systemic lupus erythematosus, hypocalcemia, and patients on chemotherapy (P&gt;0.05). Conclusion There was no statistically significant difference in the onset of PCO development with different IOL materials. Moreover, the patients’ general medical condition did not show a significant association with PCO incidence.

Postoperative discoloration of a multifocal hydrophobic acrylic lens: case report with laboratory analyses

Introduction: A case of discoloration of a multifocal hydrophobic acrylic intraocular lens (IOL), which was explanted and exchanged as well as underwent laboratory analysis, is reported. Patient and Clinical Findings: The patient presented with a corrected distance visual acuity of 20/50 and glare in the right eye 8 years after implantation. Slitlamp examination revealed a nasally decentered IOL with a whitish-brownish haze throughout. Diagnosis, Intervention, and Outcomes: The discolored IOL (ZMB00) was explanted and exchanged for a 3-piece IOL (sulcus fixation). Grossly, the explanted IOL showed a whitish discoloration of the optic only after hydration, corresponding to a yellowish-brownish discoloration observed under light microscopy. Back light scattering revealed bulk scatter throughout the optic. Light transmittance (%T) showed a slight progressive decrease starting at 500 nm when compared with %T in the directions for use (DFUs). Although modulation transfer function analysis demonstrated similar values to the control lens, the contrast of U.S. Air Force targets appeared slightly decreased. Conclusions: To the authors' knowledge, this is the first reported case of a discolored ZMB00 IOL that underwent explantation and laboratory assessment. Although current analyses did not reveal the etiology of the discoloration, surgeons should be aware of this possible occurrence with this lens design and carefully assess signs and symptoms before explantation.

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.