Intraocular Lenses: Overview of Designs, Materials, and Pathophysiologic Features.

This article provides an overview of intraocular lenses (IOLs) currently used in cataract surgery. Aspects presented include design features related to IOL construction and sites of fixation; optic, filter, and haptic materials; as well as pathophysiologic features of uveal biocompatibility, capsular biocompatibility, and postoperative IOL opacification. This overview also includes supplementary (add-on; piggyback) lenses implanted in eyes that are already pseudophakic and considerations on IOLs used in the pediatric population. Different IOLs are made available to surgeons each year, including lenses with increasingly complex design characteristics owing to advancements in manufacturing and surgical techniques.

Clinical and Surgical Outcome of a Supplementary Multifocal Intraocular Lens Implanted with a Bag-In-the-Lens Intraocular Lens: 5-Year Follow-Up.

INTRODUCTION: To assess the postoperative outcome and patient-reported satisfaction, spectacle independence, and dysphotopsia after implantation with the mutifocal Rayner Sulcoflex supplementary intraocular lens (sIOL). MATERIALS AND METHODS: We analyzed the outcome of all patients implanted with a multifocal sIOL between 2009 and 2011. In all cases, the sIOL was the Rayner Sulcoflex IOL (type 653F) and the primary IOL was a bag-in-the-lens (BIL) IOL. The data were obtained through a retrospective analysis of the patient records and by means of a questionnaire, 5 years after sIOL implantation. RESULTS: This study included 31 eyes of 20 patients. In 13 eyes, the sIOL needed explantation (n = 13, 41.94%). Dysphotopsia is a frequent complaint (12/15 patients: 80.0%) after sIOL implantation. In 13 out of 31 eyes (41.94%), pigment deposits were found on the sIOL with variable clinical complaints. Five eyes required additional surgery because of clinically significant deposits. DISCUSSION/CONCLUSION: Patients with a multifocal sIOL in combination with a BIL implantation have a higher incidence of dysphotopsia compared to previously published studies. Dysphotopsia was the main complaint and reason for explantation. We encountered a high incidence of pigmented IOL deposits. The sIOLs can be safely removed even years after implantation.

Eradication of Posterior Capsule Opacification: Documentation of a Marked Decrease in Nd:YAG Laser Posterior Capsulotomy Rates Noted in an Analysis of 5416 Pseudophakic Human Eyes Obtained Postmortem.

OBJECTIVE: (1) To report the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy rate (%) of eight rigid and foldable intraocular lens (IOL) designs in a series of 5416 pseudophakic human eyes obtained postmortem, accessioned in our center between January 1988 and January 2000. (2) To identify factors that are instrumental in reducing the incidence of posterior capsule opacification, (PCO, secondary cataract) and hence the need for Nd:YAG laser posterior capsulotomy. DESIGN: Comparative autopsy tissue analysis. PARTICIPANTS: A total of 5416 globes with posterior chamber intraocular lens (PC-IOLs) obtained postmortem received from Lions Eye Banks between 1988 and 2000. METHODS: Miyake-Apple posterior photographic technique. Special reference was given to the presence or absence of Nd:YAG laser posterior capsulotomy orifice on the posterior capsule of each eye. MAIN OUTCOME MEASURES: The Nd:YAG laser posterior capsulotomy rate (%) as of January 2000 was documented. In addition, the Nd:YAG laser posterior capsulotomy rate for each lens was plotted on a monthly basis for the same period, creating a computerized trend or "timeline" for each IOL style. RESULTS: Relatively high Nd:YAG laser posterior capsulotomy rates ranging from 20.3% to 33.4% were noted with four relatively older designs (high incidence of implantation between 1988 and the early 1990s). Four modern foldable lOLs manufactured from silicone and acrylic materials had significantly lower Nd:YAG laser posterior capsulotomy rates ranging from 0.9% (Alcon Acrysof) to 17.1%. The difference in Nd:YAG rates among the eight IOL designs was found to be significant (P < 0.0001, chi-square test). Comparing foldable versus rigid designs, the foldable IOLs were associated with a much lower Nd:YAG laser posterior capsulotomy rate (14.1% vs. 31.1%). CONCLUSIONS: By use of the six factors regarding surgical technique and IOL choice described in this article, we strongly believe that the overall incidence of PCO and hence the incidence of Nd:YAG laser posterior capsulotomy is now rapidly decreasing from rates as high as 50% in the 1980s to early 1990s. Surgical tools and IOLs are now available to bring these rates down to single digits. Careful application and use of these tools by surgeons can genuinely lead in the direction of virtual eradication of secondary cataract, the second most common cause of visual loss worldwide.

Myo/Nog cells are present in the ciliary processes, on the zonule of Zinn and posterior capsule of the lens following cataract surgery.

Myo/Nog cells, named for their expression of MyoD and noggin, enter the eye during early stages of embryonic development. Their release of noggin is critical for normal morphogenesis of the lens and retina. Myo/Nog cells are also present in adult eyes. Single nucleated skeletal muscle cells designated as myofibroblasts arise from Myo/Nog cells in cultures of lens tissue. In this report we document the presence of Myo/Nog cells in the lens, ciliary body and on the zonule of Zinn in mice, rabbits and humans. Myo/Nog cells were rare in all three structures. Their prevalence increased in the lens and ciliary body of rabbits 24 h following cataract surgery. Rabbits developed posterior capsule opacification (PCO) within one month of surgery. The number of Myo/Nog cells continued to be elevated in the lens and ciliary body. Myo/Nog cells containing alpha smooth muscle actin and striated muscle myosin were present on the posterior capsule and overlaid deformations in the capsule. Myo/Nog cells also were present on the zonule fibers and external surface of the posterior capsule. These findings suggest that Myo/Nog contribute to PCO and may use the zonule fibers to migrate between the ciliary processes and lens.

Precision Pulse Capsulotomy: Preclinical Safety and Performance of a New Capsulotomy Technology.

PURPOSE: To assess the preclinical safety and performance of a new precision pulse capsulotomy (PPC) method. DESIGN: Human cadaver eye studies and surgical, slit-lamp, and histopathologic evaluation in a consecutive series of 20 live rabbits. PARTICIPANTS: Human cadaver eyes and New Zealand white rabbits. METHODS: Precision pulse capsulotomy uses a highly focused, fast, multipulse, low-energy discharge to produce a perfectly round anterior capsulotomy instantaneously and simultaneously along all 360°. Capsulotomies are performed using a disposable handpiece with a soft collapsible tip and circular nitinol cutting element. Miyake-Apple imaging and scanning electron microscopy (SEM) of PPC were conducted in human cadaver eyes. Surgical, postoperative slit-lamp, and histopathologic assessments of PPC were performed in 20 live rabbits and were compared with manual continuous curvilinear capsulorrhexis (CCC) in the fellow eye. Anterior chamber (AC) thermocouple temperature measurements were evaluated in a subset of rabbit eyes. MAIN OUTCOME MEASURES: Capsulotomy edge circularity, SEM morphologic features and zonular movement with PPC in human cadaver eyes. Anterior chamber temperature during PPC and grading of ocular inflammation, corneal endothelial damage, anterior capsular opacification (ACO), and posterior capsular opacification (PCO). RESULTS: Miyake-Apple imaging showed minimal zonular stress, and thermocouple measurements demonstrated negligible AC temperature changes during PPC. Precision pulse capsulotomy produced round, complete capsulotomies in all 20 rabbit eyes, leading to successful in-the-bag intraocular lens (IOL) implantation. Slit-lamp examinations at 3 days and 1, 2, and 4 weeks after surgery showed no significant differences between PPC and CCC in corneal edema, AC inflammatory reaction, capsular fibrosis, ACO, and PCO. Postmortem studies showed no difference in the corneal endothelium between PPC and CCC eyes. All IOLs were well centered in PPC eyes, and histopathologic analysis showed no greater inflammatory infiltrates. CONCLUSIONS: Precision pulse capsulotomy is a new method to automate consistent creation of a perfectly circular anterior capsulotomy with a disposable handheld instrument that can be used in the normal phacoemulsification surgical sequence. Compared with CCC in fellow rabbit eyes, PPC was equally safe and showed no greater zonular stress compared with CCC in human cadaver eyes. Human cadaver eye SEM showed a much smoother capsulotomy edge compared to those produced by femtosecond laser.

Optic replacement in a novel modular intraocular lens system.

PURPOSE: The purpose of the study is to evaluate the stability and ease of replacement of a new modular intraocular lens (IOL) system consisting of a hydrophobic acrylic base unit and a hydrophobic acrylic optic in the rabbit model. METHODS: Five New Zealand white rabbits were utilized. Bilateral phacoemulsification was performed; one eye received the test IOL (ClarVista Harmoni Modular IOL System) and the other, a commercially available hydrophobic acrylic control IOL (Alcon AcrySof SA60AT). Slit-lamp examinations were performed weekly during postoperative weeks 1 to 6. IOL replacement procedures were performed at weeks 2 and 6 using standard instruments. The rabbits were sacrificed at the end of the study (week 6), with all globes analyzed grossly using the Miyake-Apple technique and sectioned and processed for histopathologic examination. RESULTS: The base component and the optic of the Harmoni IOL system remained stable and centred throughout the clinical follow up. Disengagement of the optic component from the base and replacement of the optic were safely and easily accomplished at 2 and 6 weeks postoperatively. Explantation of the control lens required posterior synechiolysis and capsular bag manipulation due to the position of the loops at the periphery of the bag, thus causing zonular stress. CONCLUSIONS: Replacement of the Harmoni optic was found to be safe and efficient compared with the control IOL, as manipulation of the capsular bag to remove haptic components is not necessary with the modular design. The base component of the modular system remained stable and centred throughout the study.

Evaluation of stability and capsular bag opacification of a new foldable adjustable intraocular lens.

BACKGROUND: Incorrect lens power remains one of the most common reasons for intraocular lens explantation/exchange. We evaluated stability and effect on capsular bag opacification of a new foldable modular lens system, with a base component and an optic component in rabbit eyes. METHODS: Bilateral phacoemulsification was performed on six rabbits; one eye received the test lens (Harmoni Modular Lens, ClarVista Medical), whereas the other received a single-piece hydrophobic acrylic control lens (SA60AT, Alcon). Slit-lamp examinations were performed at postoperative weeks 1, 2, 3, 4 and 6. All rabbits were sacrificed at week 6. After enucleation, the eyes were examined grossly from the Miyake-Apple view. Following, all globes were sectioned and processed for histopathological examination. RESULTS: The modular lens was stable in all six rabbits. Uveal biocompatibility was similar to or better in the test eyes when compared with control eyes up to 6 weeks postoperatively. Overall, capsular bag opacification was found to be significantly lower in the test eyes when compared with control eyes. At the 6-week gross examination, central posterior capsule opacification was scored as 0.58 ± 0.73 in the test group, and as 3.00 ± 1.26 in the control group (paired two samples for means t-test; two-tail P = 0.005). CONCLUSIONS: The Harmoni Modular system remains stable within the capsular bag after implantation. Due to the design of the base component featuring long loops, along with peripheral anterior and posterior square edges, the lens appeared to prevent overall capsular bag opacification in the rabbit model.

Microscopic analysis of preinsertion cutting modalities on custom, flexible iris prostheses.

PURPOSE: To determine the induced edge effects of different clinically used device postmanufacture modification styles and modalities on custom iris implants. SETTINGS: An academically affiliated multispecialty private practice group and an academic medical center. DESIGN: Laboratory study. METHODS: Sample custom iris prostheses were cut using patterns, blades, and surgical instruments described in the literature. The cut edges were evaluated with slitlamp microscopy, light microscopy, and scanning electron microscopy. RESULTS: Disposable blades yielded smoother cuts than scissors. Trephine blade brand significantly affected the cut surface smoothness of the silicone matrix. Meshwork-embedded prostheses had some irregular sharp edges where the mesh fibers were cut with all modalities, although these were worse with scissors and one tested trephine brand compared with the other. Pseudoiridectomies and scissor cuts created sharp points and corners in the device periphery. CONCLUSIONS: Postmanufacture modifications of iris implants should be minimized. The cut margins of the fiber-free implants have fewer sharp edges and may be preferable for sulcus placement. In-the-bag device placement may mitigate clinical impact of sharp edges and corners. These practices may help to minimize inflammatory sequelae postimplantation.

Ex Vivo Histological Analysis of Corneas with Manually Implanted Intracorneal Stromal Ring Segments.

Backgrond: Intracorneal ring segments (ICRSs) are utilized to correct refractive changes impacting visual acuity, commonly implanted via femtosecond laser but can also inserted manually. Corneal deposits alongside the ICRS channels are seen commonly. Methods: This study explores the histological characteristics of corneal deposits following manual ICRS implantation, comparing them to previously published articles describing femtosecond laser-assisted cases. Results: This is a retrospective analysis of three cases involving manual ICRS implantation, accumulation of whitish deposits and later explanation of the corneas due to penetrating keratoplasty (PKP). Patient demographics, ocular history, and surgical details were collected. Histological analysis employed Hematoxylin and Eosin (H&E) and Masson's trichrome staining. Whitish deposits along ICRS tracts were observed in all cases, with minimal fibroblastic transformation of keratocytes adjacent to the segments. Comparing these cases of manual to femtosecond laser-assisted ICRS implantation, in most cases, similar deposits were identified, indicating the deposits' association with the stromal tissue reaction to the ring segment and not to the surgical technique. Conclusions: This study contributes insights into the histopathology of manually implanted ICRS, emphasizing the shared nature of deposits in both insertion methods. The findings highlight the link between deposits and the stromal tissue reaction to the ring segment, irrespective of the insertion technique.

Complications of foldable intraocular lenses requiring explantation or secondary intervention: 2022 survey with update of long-term trends.

PURPOSE: To assess the complications that resulted in the explantation or secondary intervention with foldable intraocular lenses (IOLs). SETTING: University setting, Salt Lake City, Utah. DESIGN: Survey study. METHODS: For the 25th consecutive year, surgeons were surveyed regarding complications associated with foldable IOLs requiring explantation or secondary intervention over the 2022 calendar year. These forms were made available online using the ASCRS and ESCRS websites and a fax-on-demand service. Surgeons completed 1 survey for each foldable IOL requiring explantation or secondary intervention. Further analysis determined complication trends related to specific IOL styles, materials, and types over the past 16 years (2007 to 2022). RESULTS: 103 completed surveys were returned in 2022 contributing to a total of 1627 tabulated surveys since 2007. In the 2022 survey, dislocation/decentration continued to be the most common complication overall. Glare/optical aberrations was a common complication associated with multifocal IOLs continuing a 16-year trend. In addition, hydrophilic acrylic IOLs as well as some silicone lenses in eyes with asteroid hyalosis demonstrated calcification as the most common complication necessitating explantation. CONCLUSIONS: Dislocation/decentration remains the leading cause of explantation in most IOL types. Glare/optical aberrations continue to be an associated complication of multifocal IOLs suggesting this ongoing issue has yet to be resolved with this type of IOL. In addition, calcification of hydrophilic acrylic lenses and silicone lenses is a rare event but continues to occur.

Rotational stability of a new hydrophobic acrylic intraocular lens platform.

PURPOSE: To evaluate rotational stability for ease of rotation of a new intraocular lens (IOL) platform with 4 haptics in an ex vivo model and compare it with a control single-piece lens with 2 open loops. SETTING: Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. DESIGN: Experimental study. METHODS: 10 human cadaver eyes were prepared as per the Miyake-Apple technique. After injection of the test or control lens, clockwise and counterclockwise rotations were attempted with a hook, with and without an ophthalmic viscosurgical device in place. Ease of rotation was scored as (1) very easy, (2) easy, (3) difficult, and (4) very difficult. Rotation of the entire eye containing test or control IOL was also performed with a multipurpose rotator (2 minutes; 220 revolutions per minute) to evaluate its effect on IOL alignment. RESULTS: There were statistically significant differences regarding ease of rotation between test and control lenses in all 4 scenarios, with rotation being more difficult with the test lens ( P < .05, Wilcoxon signed-rank test). No change in the alignment of test or control lenses was observed after eye rotation with the multipurpose rotator. CONCLUSIONS: The new IOL platform showed greater rotational stability than the control lens in this model, owing to design features such as 4 small arcs of contact between the haptics and the bag equator, a bulge at the distal end of each haptic, and arcuate haptics with curvatures oriented toward each other.

Immunohistochemical Findings of Lens Capsules Obtained from Dead Bag Syndrome Patients.

PURPOSE: To investigate the extracellular matrix and cellular components in lens capsules extracted from patients with dead bag syndrome (DBS) through immunohistochemistry. SETTING: Department of Ophthalmology, Wakayama Medical University School of Medicine and Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah. DESIGN: Immunohistochemical experimental study. METHODS: Nine capsular bag specimens from DBS cases, as well as 2 control specimens from late-postoperative in-the-bag intraocular lens dislocation cases related to previous vitrectomy, pseudoexfoliation, and blunt trauma were included. They were processed for histopathology; unstained sections were obtained from each one, and analyzed by immunohistochemistry targeting collagen type IV, laminin, vimentin, collagen type I and fibronectin. RESULTS: Immunohistochemistry in DBS showed lens capsule stained for basement membrane components. The outer part of the anterior capsule that was split from the inner part was more markedly stained for type IV collagen as compared with the posterior part. Faint staining for fibrous posterior capsular opacification (PCO) components, e. g., collagen type I and fibronectin, was detected in limited areas, but the major portion of the capsule was free from these components. Small spotty vimentin-positive materials, suggesting the presence of cell debris, was also detected in limited samples. CONCLUSION: Small amounts of fibrotic PCO components were detected in capsules extracted from patients with DBS, but their major parts were free from PCO components. Current findings suggest small amounts of lens epithelial cells were present after surgery and secreted fibrous components before undergoing cell death process.

Pathologic comparison of asymmetric or sulcus fixation of 3-piece intraocular lenses with square versus round anterior optic edges.

OBJECTIVE: To evaluate the pathologic findings of 3-piece intraocular lenses (IOLs) with asymmetric or sulcus fixation in pseudophakic cadaver eyes, comparing IOLs with square or round edges on the anterior optic surface. DESIGN: Comparative case series with pathology. PARTICIPANTS: A total of 661 pseudophakic cadaver eyes, obtained from eye banks within the United States, implanted with different IOLs. METHODS: Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging followed by gross examination. Selected eyes were processed for complete histopathologic analysis. MAIN OUTCOME MEASURES: Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. RESULTS: Of 661 pseudophakic cadaver eyes obtained, 13 had 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges, and 14 had 3-piece lenses with anterior round edges (13 silicone lenses and 1 hydrophobic acrylic lens) without symmetric in-the-bag fixation. These 27 selected eyes were processed for complete histopathologic analysis. Gross findings in both groups were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, and iris transillumination defects. Histopathology of the 14 eyes with 3-piece IOLs with round anterior optic edges showed mild focal disruption of the iris pigmented layer and loop protrusion/erosion in the ciliary sulcus. Additional changes observed in the 13 eyes with square anterior optic edge IOLs included iris changes, such as vacuolization, disruption and loss of the pigmented epithelial layers, iris thinning and atrophy, synechiae, and pigmentary dispersion within the trabecular meshwork. One eye also exhibited initial signs of optic nerve disc cupping. CONCLUSIONS: In this series, pathologic findings were more severe in eyes implanted with 3-piece IOLs with square anterior optic edges, suggesting that IOLs with round anterior edges are more suitable for sulcus fixation. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

In-the-bag capsular tension ring and intraocular lens subluxation or dislocation: a series of 23 cases.

OBJECTIVE: To describe clinical and pathologic findings from cases of in-the-bag capsular tension ring (CTR) and intraocular lens (IOL) subluxation or dislocation. DESIGN: Retrospective case series with clinicopathologic correlation. PARTICIPANTS: Twenty-three explanted subluxated/dislocated capsular bags containing a CTR and an IOL explanted in Europe and submitted in fixative to the Berlin Eye Research Institute. METHODS: Standard gross and light microscopy of specimens, complete histopathologic analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available. MAIN OUTCOME MEASURES: Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors. RESULTS: Patients were aged 76.31 ± 8.24 years at explantation, which was performed 81.5 ± 32.2 months after implantation. The IOLs in these cases were 3-piece hydrophobic acrylic (N = 11), 1-piece hydrophobic acrylic (n = 6), 3-piece silicone (n = 4), or 1-piece hydrophilic acrylic (n = 2) designs; all CTRs were made of poly(methyl methacrylate). Available information on associated ocular conditions included pseudoexfoliation (n = 17), glaucoma (n = 4), vitrectomy/retina surgery (n = 3), and trauma (n = 1). Complete histopathologic assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering's ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7 ± 23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered. CONCLUSIONS: Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation in this series, providing further evidence that a fine line exists between zonular insufficiency that can be stabilized with the CTR alone and that requiring further support. Analyses of large series may help to define common factors associated with this complication, as well as surgical planning and employment of various endocapsular support devices to enhance postoperative zonular stabilization.

Pathologic assessment of complications with asymmetric or sulcus fixation of square-edged hydrophobic acrylic intraocular lenses.

OBJECTIVE: One-piece hydrophobic acrylic intraocular lenses (IOLs) are not indicated for sulcus fixation because of complications, such as uveitis-glaucoma-hyphema syndrome. Similar complications may also be observed with 3-piece lenses that have a square optic edge on the anterior surface. The objective of this study was to provide pathologic evidence of complications related to out-of-the-bag fixation of 1- or 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges. DESIGN: Comparative case series with pathology. PARTICIPANTS: A total of 661 pseudophakic cadaver eyes obtained from eye banks within the United States, implanted with different IOLs. METHODS: Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging, followed by gross examination. Selected eyes were processed for complete histopathologic analysis; some of them were explanted before histopathology to allow for direct light microscopic evaluation of the lenses. MAIN OUTCOME MEASURES: Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. RESULTS: A total of 256 eyes were implanted with hydrophobic acrylic IOLs with anterior and posterior square optic edges; 18 of them exhibiting asymmetric or sulcus IOL fixation (six 1-piece and twelve 3-piece IOLs) underwent complete histopathologic evaluation and were compared with the contralateral eyes with symmetric in-the-bag IOL implantation. Pathologic findings were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, iris transillumination defects, iris changes including vacuolization/disruption/loss of the pigmented layer, iris thinning, and iris atrophy, as well as synechiae and loop erosion in the case of 3-piece lenses. Findings were more significant in comparison with the control contralateral eyes and were particularly evident in relation to the sulcus-fixated haptic in the case of 1-piece lenses. The majority of the eyes with 3-piece lenses showed signs of complicated surgery. CONCLUSIONS: This study provides pathologic correlation of complications that were clinically reported in the peer-reviewed literature in relation to sulcus fixation of 1-piece hydrophobic acrylic IOLs. The eyes with 3-piece lenses generally exhibited evidence of complicated surgery; therefore, all pathologic findings in those cases may not be strictly attributed to the out-of-the-bag fixation.

Force of lifelong crystalline lens growth: chronic traumatic mechanical insult to the choroid.

PURPOSE: To calculate the forces applied to the uvea and retina as a result of lifelong crystalline lens growth. DESIGN: Retrospective study. SETTING: MRI Research, Inc., Middleburg Heights, Ohio; Institute of Ophthalmology and Visual Science UMDNJ-New Jersey Medical School, Newark, New Jersey; USC Psychology University of Southern California, Los Angeles. METHODS: Magnetic resonance images were acquired from 15 phakic/pseudophakic eye pairs in patients with cataract (ages 46 to 83 years). Choroidal lengths were measured. The forces required to produce differences between phakic/pseudophakic choroidal lengths were calculated. RESULTS: The length of the choroid is greater in the phakic eye compared with the corresponding pseudophakic eye (n = 15), and this difference increases with age (P = .00006; power = 0.99). The corresponding choroidal strain also increases with age (P = .00003, power = 0.99) as do the forces required to produce such a change in choroidal length (P = .000008, power = 0.99). CONCLUSIONS: The authors theorize that lifelong crystalline lens growth applies a chronic, traumatic, mechanical insult to the uvea and retina. This previously unknown, ever-increasing, force appears to stretch the choroidal tissue and may be an intraocular pressure-independent modifiable risk factor for retinal disease. Implications exist for understanding the pathophysiology of retinal diseases in the aging eye that are often comorbid with cataracts, for example, glaucoma, macular degeneration, and diabetic retinopathy.

Clinical and histopathological findings in the dead bag syndrome.

PURPOSE: To describe the findings of a recently described syndrome, the dead bag syndrome, in which the capsular bag appears to be clear many years postoperatively, becoming diaphanous and floppy and unable to support the intraocular lens (IOL) within it. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. DESIGN: Case series with clinicopathological correlation. METHODS: Of 10 cases suspected to represent a dead bag syndrome, 8 IOLs and 7 capsular bags were removed because of subluxation or dislocation. The 7 capsular bags available for analysis were fixed in formalin and submitted to histopathological examination (hematoxylin-eosin and Masson trichrome stains). The associated explanted IOLs in 5 cases were also examined microscopically. RESULTS: Histopathologic examination of the 7 capsular bags showed capsular thinning and/or splitting. Lens epithelial cells (LECs) were completely absent on 2 specimens, whereas the other 5 specimens had rare LECs on the inner surface of the capsule. Explanted IOLs were 3-piece silicone IOLs or single-piece hydrophobic acrylic IOLs. 1 IOL optic showed a small amount of granular pigment deposition, but the optics of the other 4 IOLs were unremarkable. CONCLUSIONS: In this syndrome, there seems to be an absence of secondary proliferation of LECs and fibrotic changes. The capsule shows some signs of degradation, such as thinning and/or splitting. Weakness of zonular attachments seems to be an associated finding, with subsequent in-the-bag IOL dislocation. Further studies are necessary to ascertain the etiology of this condition.

Late-onset toxic anterior segment syndrome after possible aluminum-contaminated and silicon-contaminated intraocular lens implantation.

PURPOSE: To describe an outbreak of late-onset toxic anterior segment syndrome (TASS) after the implantation of a specific hydrophilic acrylic intraocular lens (IOL). SETTING: University Hospitals of Leuven, Belgium. DESIGN: Retrospective, single-center, observational study. METHODS: All eyes undergoing cataract surgery with a monofocal, toric, or enhanced depth-of-focus (EDoF) Synthesis (Cutting Edge) IOL between August 2019 and March 2020 were reviewed. Data were collected on the surgical procedure, postoperative course, time until onset of symptoms, clinical features, and additional treatments. A laboratory surface analysis of all 3 IOL subtypes was performed in the Intermountain Ocular Research Center at the University of Utah, USA. Furthermore, other possible causes of prolonged postoperative inflammation rather than the IOL itself were investigated. RESULTS: Among the 203 eyes included, 28 TASS cases were identified (13.8%), among which 25 received a monofocal IOL, and 3 received an EDoF IOL. The mean time until onset was 28.9 (±19.9) days. Patients presented with anterior chamber cells (92.9%), deposits on the IOL (57.1%), or fibrinous inflammation (35.7%). 4 eyes (14.3%) underwent a surgical intervention, whereas 24 eyes showed a resolution of inflammation with topical therapy alone. Laboratory analysis showed the presence of both aluminum and silicon particles on the monofocal IOL, silicon particles only on the EDoF IOL, and no particles on the toric IOL surface. CONCLUSIONS: This report describes an outbreak of atypical, late-onset TASS after cataract surgery, possibly correlated with aluminum and silicon contamination of the IOL surfaces.

Effect of longitudinal and torsional ultrasound on corneal endothelial cells: experimental study in rabbit eyes.

PURPOSE: To compare corneal endothelial damage from longitudinal and torsional ultrasound during phacoemulsification. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: 9 New Zealand white rabbits underwent bilateral surgery. After incision, the Intrepid Balanced Tip of the Centurion Ozil handpiece was inserted into the anterior chamber, and the following settings were used: 50 mL/min flow, 70 mm Hg intraocular pressure, 600 mm Hg vacuum, and 60% longitudinal (1 eye) or torsional (contralateral eye) ultrasound for 30 seconds. Cumulative dissipated energy (CDE) was noted. After euthanasia and enucleation, the corneas were removed, stained with trypan blue/alizarin red, and photographed (400× photographs from 5 specific areas and 1 overview photograph from each corneal button). The ImageJ program was used to evaluate cell damage and loss in the photographs obtained from each cornea. RESULTS: Cavitation bubbles around the phacoemulsification tip were generally observed in the longitudinal group. CDE was 17.4 ± 0.58 and 6.93 ± 0.15 in the longitudinal and torsional groups, respectively (P = .003). The percentage of intact cells was statistically higher in the torsional group (94.22% ± 5.99% vs 56.85% ± 22.29%), and the percentage of lost cells was statistically higher in the longitudinal group (42.10% ± 22.02% vs 4.97% ± 6.23%) (P = .003). This was observed in the analysis of the 400× photographs and the overview photographs. CONCLUSIONS: This study suggests that torsional ultrasound was associated with significantly less corneal endothelial cell damage than classical longitudinal tip motion, providing further insight on mechanisms of corneal endothelial damage during phacoemulsification.

Effect of phacoemulsification fluid flow on the corneal endothelium: experimental study in rabbit eyes.

PURPOSE: To quantify the damage to the corneal endothelium from the flow of a balanced salt solution during phacoemulsification. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. DESIGN: Experimental study. METHODS: 12 New Zealand white rabbits received bilateral surgery. 6 eyes served as controls with no irrigation (incision only). In 18 eyes, the Intrepid Balanced tip of the Centurion Ozil (Alcon Laboratories, Inc.) handpiece was inserted into the anterior chamber for continuous irrigation at 50 mL/min with either 250 or 500 mL of balanced salt solution. After killing humanely and enucleation, the corneas were removed, stained with trypan blue-alizarin red, and photographed in a standardized manner (×400 photographs from 5 specific areas and 1 overview photograph from each corneal button). The ImageJ program was used to evaluate cell damage and loss in the photographs obtained from each cornea. RESULTS: Analysis of the ×400 photographs showed no statistically significant differences between control, 250 mL, and 500 mL groups in the percentage of intact, damaged, or lost cells (P = .896, .851, and .972 respectively). For the overview photographs, the differences in areas of intact and damaged cells among the groups were statistically significant, likely because of the peripheral areas of damage related to touches between the phacoemulsification tip and the endothelium during irrigation. CONCLUSIONS: The volume of balanced salt solution flow alone did not seem to be a major contributing source of endothelial cell damage and loss, providing further insight into mechanisms of corneal endothelium damage during phacoemulsification.