Experimental investigation on mechanism of hydrophilic acrylic intraocular lens calcification

A unique late-onset intraocular lens opacification 23 years after implantation: a clinical and laboratory case report

We report an unusual, rare case of opacification of the hydrophilic acrylic intraocular lens (IOL) 23 years after the initial surgery with significant visual deterioration. Opacification of the hydrophilic acrylic IOL was primarily due to the formation of folds on the surface of the lens material, and less so due to calcium phosphate deposits. Calcification opacification can be attributed to recent events, as evidenced by deposits of dicalcium phosphate dihydrate (CaHPO42H2O) and octacalcium phosphate (Ca8H2(PO4)65H2O), both of which are transient calcium phosphate phases, converting hydrolytically to the thermodynamically most stable hydroxyapatite (Ca10(PO4)6(OH)2). To our knowledge, this case of hydrophilic acrylic IOL opacification is the only one that has been described so late, 23 years after cataract surgery.

Long-Term Outcome and Complications of IOL-Exchange

Purpose

To describe the long-term outcome after intraocular lens (IOL) exchange for IOL-opacification with a focus on any occurring complications.

Patients and Methods

Patients with an IOL exchange for opacified IOLs (Lentis LS-502-1) were identified. Medical records and information from the treating ophthalmologists were reviewed. Visual outcomes and any occurring complications after the IOL exchange were analyzed.

Results

IOL exchange was performed in 48 eyes of 46 patients and significantly improved best-corrected distance visual acuity from 0.42 ± 0.32 logMar (mean ± SD) in opacified lenses to 0.25 ± 0.28 logMar after IOL exchange. Nine of the 48 eyes (19%) underwent 11 further surgical procedures for complications due to four indications: IOL dislocation (n = 2, 4%), retinal detachment (RD) (n = 6, 12%), epiretinal membrane (n = 2, 4%), and pupillary block (n = 1, 2%). Three eyes (6%) developed a temporarily elevated intraocular pressure. Temporary postoperative cystoid macular edema was found in 2 eyes (4%).

Conclusion

IOL exchange can restore vision owing to IOL opacification in most cases. Nonetheless, IOL exchange is not an easy or risk-free procedure. This may lead to sight-threatening complications, even in eyes without predisposing ocular comorbidities.

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

BACKGROUND

Opacification through calcification of hydrophilic acrylic intraocular lenses is a serious complication of cataract surgery, which usually results in explantation of the lens. In the process of calcification, the intraocular lens material plays a crucial 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.

OBJECTIVE

The present study investigated whether the hydrophobic surface properties of hydrophilic acrylic lenses can prevent calcification.

MATERIAL AND METHODS

Using an electrophoretic in vitro model of calcification, two hydrophilic lenses with hydrophobic surface properties were compared to two hydrophilic lenses and a hydrophobic 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).

RESULTS

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.

CONCLUSION

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 a risk of calcification in these lens models.

Spectroscopic characterization of calcium phosphate precipitated under human eye conditions: An in vitro study

Calcification is a well-known process of calcium phosphate mineralization observed in intraocular lenses. Despite the many works conducted in this field, there is no strict explanation of the mechanisms of this process. In order to better understand the phenomenon, i.e., the mechanisms and structural conditions that promote calcification, any research observations should be conducted under conditions that best reflect those of the human eye. Taking into account the specific anatomy and physicochemical conditions of the human eye, the problem under discussion becomes difficult to solve in vitro. In the present study, calcium phosphates formed under conditions similar to those in the human eye were characterized using SEM/EDS and infrared spectroscopy. Conducted study showed the formation of white spherical precipitates, which are unstable when extracted from solution. Such precipitates were characteristic of solutions containing 1.5-3.0 mM² of solutes. Elemental analysis showed a Ca/P ratio of 1.64-1.65, which is similar to the ratio for hydroxyapatite (1.67). Chemical structure analysis revealed the presence of broad bending and stretching bands at 475-830 cm^-1 and 880-1250 cm^-1, respectively, which are characteristic of PO₄^3- groups in apatite calcium phosphates. In further analysis involving numerical fitting the bands corresponding to apatitic PO₄^3- and indicating the presence of calcium phosphates hydration were found. The results allow the selection of immersion media for further studies involving the incubation of hydrogel intraocular lenses.

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

PURPOSE

To conduct a new exploration and analysis of the ion and fatty acid levels of a medium in which calcified hydrophilic intraocular lenses (IOLs) are present.

SETTING

Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China.

DESIGN

Retrospective, laboratory observational case series.

METHODS

11 patients (11 eyes) who had implantation of foldable hydrophilic acrylic 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.

RESULTS

10 of 11 cases were female with unilateral opacification, and 7 cases had both-eye cataract surgery, including 1 first eye and 6 second eyes with IOL opacification. 4 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 3 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.

CONCLUSIONS

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.

Explantation of a sutureless scleral fixated Carlevale intraocular lens due to calcification: a clinical and laboratory report

BACKGROUND

Hydrophilic intraocular lens opacification is a rare complication due to calcification. With current new surgical techniques, including lamellar endothelial keratoplasty and vitrectomies, this irreversible complication is becoming more common. In this case study, we present clinical and laboratory features of a case of Carlevale hydrophilic acrylic IOL calcification.

CASE PRESENTATION

Observational case report of a single incident case. An 83-year-old man was referred to our ophthalmic department complaining of right eye vision blurring for six months. Slit-lamp biomicroscopy revealed IOL opacification. Deposits of calcium phosphate were found both on the IOL's surface and inside it, according to thorough investigation using optical, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectrometry.

CONCLUSIONS

To the best of our knowledge, this is the first case to describe the laboratory evidence of Carlevale hydrophilic IOL calcification, suggesting possible explanation mechanisms based on underlying pathology and surgical technique. It reminds us that these findings suggest that physicians should be aware of possible hydrophilic IOL calcification.

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.

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.

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.

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.

Microscopic Characteristics of Late Intraocular Lens Opacifications

CONTEXT.—

The increases in overall life expectancy and in lens surgeries performed on younger patients have resulted in a significant increase in the anticipated duration of artificial intraocular lenses (IOLs) in the eye. Thus, the physicochemical properties of the IOL become a critical issue, and several types of postoperative IOL opacifications have been reported.

OBJECTIVE.—

To describe the microscopic characteristics of opacified IOLs. Glistenings and subsurface nanoglistenings are fluid-related phenomena developing mainly in hydrophobic acrylic IOLs and are associated with aqueous influx into the IOL matrix. Calcification presents in hydrophilic acrylic or silicone IOLs as deposits of hydroxyapatite or other phases of calcium. Snowflake degeneration is less common, and it manifests in older polymethyl methacrylate IOLs.

DATA SOURCES.—

PubMed and ScienceDirect databases were searched for the following keywords: intraocular lens, IOL, cataract surgery, phacoemulsification, opacification, glistening, subsurface nanoglistenings, calcification, snowflake degeneration. English-language articles published up to October 15, 2019 were included in the study. The manuscript contains mainly a literature review; however, it was supplemented with original investigations from the David J. Apple International Laboratory for Ocular Pathology.

CONCLUSIONS.—

Glistenings and subsurface nanoglistenings should be evaluated in a hydrated state and at room temperature; they manifest as microvacuoles sized from 1.0 to greater than 25.0 μm and less than 200 nm, respectively. Calcification deposits are situated on or underneath the surface of the IOL and can be stained with a 1% alizarin red solution or with the von Kossa method. Snowflake degeneration manifests as "particles" or "crystals," causing whitish IOL discoloration. Scanning electron microscopy or energy dispersive X-ray spectroscopy may improve the diagnostic accuracy.

Physicochemical Analysis of Sediments Formed on the Surface of Hydrophilic Intraocular Lens after Descemet's Stripping Endothelial Keratoplasty

An intraocular lens (IOL) is a synthetic, artificial lens placed inside the eye that replaces a natural lens that is surgically removed, usually as part of cataract surgery. The opacification of the artificial lens can be related to the formation of the sediments on its surface and could seriously impair vision. The physicochemical analysis was performed on an explanted hydrophilic IOL and compared to the unused one, considered as a reference IOL. The studies were carried out using surface sensitive techniques, which can contribute to a better understanding of the sedimentation process on hydrophilic IOLs’ surfaces. The microscopic studies allowed us to determine the morphology of sediments observed on explanted IOL. The photoelectron spectroscopy measurements revealed the presence of organic and inorganic compounds at the lens surface. Mass spectroscopy measurements confirmed the chemical composition of deposits and allowed for chemical imaging of the IOL surface. Applied techniques allowed to obtain a new set of information approximating the origin of the sediments’ formation on the surface of the hydrophilic IOLs after Descemet’s stripping endothelial keratoplasty.

Variation in intraocular lens calcification under different environmental conditions in eyes with supplementary sulcus-supported lenses

Purpose

Analysis of explanted intraocular lenses (IOLs) from pseudophakic eyes with supplementary sulcus-supported IOLs.

Methods

In this laboratory investigation, ten supplementary and capsular bag IOLs were analyzed. All lenses were received between January 2012 and March 2018. Explants were examined morphologically with histological and electron microscopic techniques and patients’ medical history was evaluated. Additionally, we used a technique new to this field: Transmission Electron Microscopy and electron diffraction pattern analysis was performed to investigate the structure of the opacifying crystals in detail.

Results

Eleven lenses were explanted due to IOL opacification from seven polypseudophakic eyes: In three cases the supplementary lens calcified, in three cases the capsular bag IOL (both lenses analyzed) and in one case both IOLs (only the supplementary was received). Additional surgical procedures and comorbidities included pars plana vitrectomy or Descemet stripping endothelial keratoplasty and diabetes mellitus. For each opacified lens, a varying layer of a Calcium phosphate beneath the optic surface was apparent. Crystal characterization revealed its composition to be Hydroxyapatite.

Conclusions and Importance

We report on a series of secondary calcification in lenses explanted from polypseudophakic eyes. In some cases, calcification occurred in the capsular bag lens, in other cases in the supplementary lens, or in both. The severity of the morphological change could be related to the comorbidities and the presence of surgery subsequent to the lens implantations. Detailed morphology of the opacifying crystals was revealed.

•

Intraocular lenses exhibited calcification in a series of polypseudophakic eyes.

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Pathology occurred in the capsular bag lens, the supplementary lens, or in both.

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Calcification was associated with different environmental factors.

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Depending on the factor, morphology and pattern of the opacity differed.

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Transmission Electron Microscopy revealed the opacifying crystals' ultrastructure.

Large-scale opacification of a hydrophilic/hydrophobic intraocular lens

PURPOSE

To determine the prevalence and risk factors related to the opacification of the LS-502-1 intraocular lens.

METHODS

Cross-sectional study including patients submitted to cataract surgery between January 2010 and March 2012, with implantation of the LS-502-1 intraocular lens. Past medical history was registered and a complete ophthalmologic evaluation, that included best-corrected visual acuity, slit-lamp examination and fundoscopy, was performed. Anterior segment photographs were taken whenever intraocular lens opacification was present.

RESULTS

One hundred and sixty-nine eyes of 154 patients were included, mean age 78.5 ± 7.9 years. The average follow-up after intraocular lens implantation was 65.6 ± 10.0 months. Intraocular lens opacification was seen in 53.3% (n = 90) and presented as one of four different patterns: peripheral (15.6%, n = 14), central (4.4%, n = 4), diffuse (71.1%, n = 64) and superficial white deposits (8.9%, n = 8). There was no statistically significant association with systemic or ophthalmic conditions. In patients with bilateral implantation, intraocular lens opacification in one eye was significantly related to intraocular lens opacification in the fellow eye. A significant variability in opacification was found across intraocular lens serial numbers: the odds ratio for opacification in intraocular lens with serial number beginning with 200003 was 6.0 when comparing with the remaining lenses.

CONCLUSION

The opacification prevalence of the LS-502-1 intraocular lens was 53.3%, which is the highest ever described for any intraocular lens model. Our results suggest that this occurrence is secondary to an interaction between unknown patient variables and problems related to intraocular lens manufacturing and storage procedures.

Late postoperative opacification of a hydrophilic-hydrophobic acrylic intraocular lens

PURPOSE

To report late postoperative opacification of a model of hydrophilic-hydrophobic acrylic intraocular lens (IOL) as well as the clinical consequences and laboratory characteristics.

SETTING

Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.

DESIGN

Retrospective case series.

METHODS

Medical records were reviewed of patients with Lentis LS-502-1 IOL opacification reporting visual loss who had IOL explantation between November 2013 and March 2015. Patients were identified in the emergency room or during regular follow-up visits. Explanted IOLs were analyzed at the Ophthalmic Explants Biobank, Vissum, Spain, or at the John A. Moran Eye Center, University of Utah, USA.

RESULTS

Twenty opacified IOLs were explanted from 19 patients. The mean interval between cataract surgery and diagnosis of opacification was 29.15 months ± 9.57 (SD) (range 6 to 45 months). Opacification led to a statistically significant reduction in corrected distance visual acuity (mean 0.86 ± 0.76 logMAR; P < .001) and occurred in 5.1% of the hydrophilic-hydrophobic acrylic IOLs implanted at the department. The most frequently associated medical conditions were arterial hypertension, diabetes, and glaucoma. All IOLs but 1 had a similar pattern of opacification, with yellowish diffuse opacification uniformly distributed and calcium deposits on the surface and/or subsurface of the optic and haptics and within the IOL material.

CONCLUSIONS

Opacification of the hydrophilic-hydrophobic acrylic IOL was found in a significant number of patients and had a significant effect on their vision. The opacification was attributed to primary calcification.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Serial intraocular lens opacifications of different designs from the same manufacturer: Clinical and light microscopic results of 71 explant cases

PURPOSE

To report clinical findings and light microscopic results of 71 opacified hydrophilic acrylic intraocular lenses (IOLs).

SETTING

Vivantes Klinikum Neukoelln, Ophthalmology Department, Berlin, Germany.

DESIGN

Retrospective case series.

METHODS

Sixty-three patients (71 eyes) were referred to the clinic because of vision-impairing IOL opacification between December 2012 and September 2016 after routine cataract surgery elsewhere. The explanted IOLs were analyzed with light microscopy at the John A. Moran Eye Center (University of Utah, Salt Lake City, Utah, USA). Medical records were reviewed for visual acuity, comorbidities, and complications. Clinical follow up was 6 months.

RESULTS

Seventy-one opacified 1-piece or 3-piece hydrophilic acrylic IOLs (Lentis) of different designs from 2009 to 2012 (LS-502-1, LS-402-1Y, LS 312-1Y, LS-313-1Y, L-402, L-312) were found. Morphological findings were surface, subsurface, or deep calcifications of the IOL material. Explantation was performed 4 years ± 1.2 (SD) after initial phacoemulsification. The mean patient age was 78.6 ± 8.2 years. Ocular and systemic comorbidities were found without statistical correlation: the most frequent were diabetes, uveitis, and glaucoma. The preoperative mean corrected distance visual acuity changed from 0.63 ± 0.47 logarithm of the minimum angle of resolution (logMAR) to 0.20 ± 0.28 logMAR postoperatively (P < .001).

CONCLUSIONS

Different designs of IOLs by the same manufacturer, implanted between 2009 and 2012, developed late calcification with significant visual loss after routine cataract surgery. No medical, surgical, or ophthalmologic trigger could be determined. A manufacture issue might be the reason for the opacification.

Calcification of Hydrophilic Acrylic Intraocular Lenses With a Hydrophobic Surface: Laboratory Analysis of 6 Cases

PURPOSE

To investigate the nature and characteristic features of deposits causing opacification of intraocular lenses (IOLs) based on the examination of clinical findings using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) analysis.

DESIGN

Retrospective, observational case series.

METHODS

This is a multicenter study of 6 hydrophilic acrylic IOLs (Lentis LS-502-1; Oculentis GmbH, Berlin, Germany) with a hydrophobic surface that were explanted from 5 patients because of opacification. Three patients had an uncomplicated phacoemulsification. One patient underwent combined phacoemulsification and pars plana vitrectomy for retinal detachment and later silicone oil endotamponade owing to redetachment. The last patient had a pars plana vitrectomy and silicone oil instillation combined with phacoemulsification for tractive retinal detachment and diabetic retinopathy. The explanted lenses were submitted to our laboratory and were examined by SEM and EDX in order to identify the morphologic features and the composition of the deposits.

RESULTS

SEM and EDX analyses confirmed the presence of calcific deposits in the interior of the opacified hydrophilic IOLs, with a pattern showing the formation of lumps on the surface. The lumps were due to subsurface formation of calcium phosphate crystalline deposits. The crystallite clusters seemed to diffuse from the IOL interior to the surface.

CONCLUSIONS

We demonstrated the calcification pattern of the hydrophilic IOL (Lentis LS-502-1) with a hydrophobic surface. Although hydrophilic acrylic lenses have a hydrophobic surface, the development of calcification is a possible threat initiating from the hydrophilic subsurface of the IOLs.

Anterior surface opacification of intraocular lenses after Descemet's stripping automated endothelial keratoplasty

Descemet's stripping automated endothelial keratoplasty (DSAEK) is today recognised as the surgical procedure of choice for corneal endothelial dysfunction. The triple procedure (either staged or combined), whereby cataract surgery can be performed at the same time as endothelial keratoplasty, is well suited for patients with Fuch's endothelial dystrophy with decreased vision due to endothelial guttata, early stromal oedema and cataract formation. Recognised complications of DSAEK include donor graft detachment/dislocation, primary graft failure and pupillary block by air. Intraocular lens (IOL) opacification is a complication that is becoming apparent in patients who have undergone DSAEK and, to date, no definitive mechanism of such opacification has been discovered. Primary postoperative optic opacification of hydrophilic acrylic IOL designs has been attributed to the formation of calcium phosphate deposits. This has led to changes in lens designs, manufacturing processes and packaging. Secondary calcification is thought to be caused by environmental factors unrelated to the IOL model, such as breakdown of the blood-aqueous barrier. In this report, four cases of IOL anterior surface opacification are described in patients who required both cataract surgery and DSAEK. Only one case had cataract surgery and DSAEK performed concurrently, with the remainder having DSAEK performed at variable timeframes after cataract surgery.

Intraocular Lens Opacification following Intracameral Injection of Recombinant Tissue Plasminogen Activator to Treat Inflammatory Membranes after Cataract Surgery

Purpose. To report 7 cases of intraocular lens (IOL) opacification following treatment of postoperative anterior chamber fibrin with recombinant tissue plasminogen activator (rtPA) after cataract surgery. Methods. Retrospective case series of 7 eyes in 7 patients who developed IOL opacification after receiving rtPA for anterior chamber inflammatory membrane formation resulting from phacoemulsification cataract surgery. Three explanted IOLs were investigated with light microscopy, histochemical analysis, scanning electron microscopy, and X-ray spectrometry. Results. All patients underwent uncomplicated cataract surgery and posterior chamber hydrophilic IOL implantation. Anterior chamber inflammatory membranes developed between 1 and 4 weeks of surgery and were treated with intracameral rtPA. IOL opacification was noted between 4 weeks and 6 years after rtPA treatment with reduced visual acuity, and IOL exchange was carried out in 3 patients. Light microscopy evaluation revealed diffuse fine granular deposits on the anterior surface/subsurface of IOL optic that stained positive for calcium salts. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS) confirmed the presence of calcium and phosphate on the IOL. Conclusions. Intracameral rtPA, though rapidly effective in the treatment of anterior chamber inflammatory membranes following cataract surgery, may be associated with IOL opacification.

[Opacification of an intraocular lens: calcification of hydrophilic intraocular lenses after gas tamponade of the anterior chamber]

A patient with endothelial dystrophy was treated with Descemet stripping automated endothelial keratoplasty (DSAEK) combined with cataract extraction and implantation of a hydrophilic intraocular lens (IOL, Lentis-L312, Oculentis) but visual acuity dropped from 0.15 logMAR to 0.52 logMAR 18 months later due to calcification of the IOL. With new methods of lamellar corneal transplantation being used more frequently the number of necessary anterior chamber tamponades with air/gas are increasing. In cataract cases in which a gas tamponade and transplantation might be necessary later on (cornea guttata), hydrophilic IOLs should be avoided.