3-D X-ray computed tomography in the analyses of intraocular lenses explanted because of postoperative opacification.

PURPOSE: X-ray computed tomography (X-ray CT) describes the acquisition and reconstruction of 2-D X-ray transmission images to create a 3-D representation of the specimen. The aim of this study was to use this technology in the analyses of intraocular lenses (IOLs) explanted because of optical opacification occurring postoperatively. SETTING: John A. Moran Eye Center, and Utah Nanofab, University of Utah, Salt Lake City, Utah, USA. DESIGN: Laboratory Study. METHODS: A hydrophilic acrylic and a silicone lens (the later from an eye with asteroid hyalosis) explanted because of postoperative calcification, as well as a polymethylmethacrylate (PMMA) lens explanted because of snowflake degeneration underwent analysis under gross and light microscopy. Then, they were attached to an appropriate support and scanned under a Zeiss Xradia Versa X-ray microscope. After data acquisition, data segmentation was performed with a commercially available program to separate image data into components. RESULTS: Morphology, size/volume, and specific location of calcified deposits on the surface or within the substance of explanted IOLs could be demonstrated by X-ray CT within the entire volume of each lens with high contrast and resolution. The PMMA lens showed multiple spaces/fissures in relation to Nd:YAG pitting of the optic, and what appeared to be sheets of delaminated PMMA material at different levels within the optic substance. CONCLUSION: The key benefit of X-ray CT is that it can be done without physically sectioning the specimen. This preliminary study demonstrates that this technology can be potentially useful in the imaging and analyses of explanted, opacified lenses.

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.

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.

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.

Corneal endothelium protection provided by ophthalmic viscosurgical devices during phacoemulsification: experimental study in rabbit eyes.

PURPOSE: To compare the protection of the corneal endothelium provided by a cohesive and a dispersive ophthalmic viscosurgical device (OVD) against damage from torsional ultrasound and simulated lenticular debris during phacoemulsification. SETTING: University setting, Salt Lake City, Utah. DESIGN: Experimental study. METHODS: 15 New Zealand rabbits were included. After incision, each eye received cohesive or dispersive OVD (ProVisc or Viscoat). 10 1.0 mm beads were injected to simulate lenticular debris. The Intrepid Balanced tip (Centurion Ozil handpiece) was inserted into the anterior chamber, and 60% torsional ultrasound with 50 mL/min flow, 70 mm Hg intraocular pressure, and 600 mm Hg vacuum was applied (20 seconds). Cumulative dissipated energy (CDE) was noted. After euthanasia and enucleation, corneas were removed, stained with trypan blue/alizarin red, and photographed (5 ×400 magnification photos and 1 overview photograph from each cornea). ImageJ was used to evaluate cell damage and loss. RESULTS: CDE was 4.70 ± 0.26 and 4.64 ± 0.10 in the cohesive and dispersive OVD groups, respectively ( P = .8647). The analysis of the ×400 photographs showed that the percentage of intact cells was statistically higher in the dispersive OVD group ( P = .0002), whereas the percentages of damaged and lost cells were statistically higher in the cohesive OVD group ( P = .0002 and .0059, respectively). Overview photographs revealed the presence of residual OVD on the endothelium, especially in the dispersive group. CONCLUSIONS: In this experimental study using a rabbit model, the corneal endothelium protection provided by the dispersive OVD was superior to that provided by the cohesive OVD.

Wave-like calcification on the posterior surface of an acrylic hydrophilic bag-in-the-lens (BIL) implant.

Purpose: To report secondary opacification of a hydrophilic bag-in-the-lens (BIL) which is a rare manifestation that can happen years after initial surgery. Observations: We describe a case of a prominent wave-like, rippled opacification on the posterior surface of the BIL. The opacification was composed of calcium deposits and seems to start in the periphery as a ring and progresses to the centre of the posterior surface. Due to the specific design of the BIL, there is direct contact between the BIL and the posterior chamber, both with the space of Berger, and the anterior hyaloid, particularly in this very hyperopic eye. Conclusions and importance: Abnormal fluid flow and stagnation in an unusual retrolenticular space is a possible explanation for this unusual pattern of posterior surface opacification.

Effect of simulated lenticular debris on corneal endothelial cells: experimental study in rabbit eyes.

PURPOSE: To evaluate mechanical damage of simulated lenticular debris on corneal endothelial cells during phacoemulsification. SETTING: University setting, Salt Lake City, Utah. DESIGN: Experimental study. METHODS: 12 New Zealand rabbits underwent bilateral surgery. After incision, 10 1.0 mm beads were injected into the anterior chamber of test eyes to simulate lenticular debris. A balanced salt solution was injected into the contralateral eyes with the same injector. The Intrepid Balanced Tip of the Centurion Ozil handpiece was inserted into the anterior chamber, and 60% torsional ultrasound was applied for 20 seconds with 50 mL/min flow, 70 mm Hg intraocular pressure, and 600 mm Hg vacuum. Cumulative dissipated energy (CDE) was noted. After euthanasia 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. RESULTS: CDE was 4.64 ± 0.19 for test eyes with beads and 4.66 ± 0.17 for control eyes without beads ( P = .58). The percentage of intact cells was statistically higher in the control group ( P = .0005), whereas the percentages of damaged and lost cells were statistically higher in the test group ( P = .0010 and .0005, respectively). This was observed in the analysis of the ×400 photographs and overview photographs. CONCLUSIONS: This study suggests that lenticular debris swirling around the anterior chamber may cause significant damage to the corneal endothelium, providing further insight on mechanisms of damage during phacoemulsification.