Effect of heparin-surface-modified intraocular lenses on postoperative inflammation after phacoemulsification: a randomized trial in a United States patient population. Heparin-Surface-Modified Lens Study Group

Cataract inhibitors: Present needs and future challenges

Cataracts result from opacification of the ocular lens and represent the leading cause of blindness worldwide. After surgical removal of the diseased lens material and implantation of an artificial intraocular lens, up to 50% of cataract patients develop a secondary lens defect called posterior capsular opacification (PCO). While vision can be restored in PCO patients by a laser-mediated capsulotomy, novel therapies involving inhibition of aldose reductase are now being developed to prevent PCO development and complications of laser capsulotomy. A question we wished to address was whether cataract surgeons believe there is an unmet need for a preventative PCO therapy, whether they would prescribe such a therapy were it available, and to assess their perceptions regarding the benefits of and obstacles to adopting novel PCO therapies in the place of laser capsulotomy. We gathered perspectives from adult, pediatric, and veterinary cataract surgeons using an online questionnaire. From 161 surgeon responses, we found that the majority of adult, pediatric, and veterinary cataract surgeons (78% n = 35, 88% n = 37, and 96% n = 71 respectively) believed there is an unmet need for preventative PCO therapy, with more than 95% expressing interest in incorporating such therapy into surgical protocols. Perceived benefits included optimizing visual outcomes, avoiding the need for additional procedures, eliminating complications related to neodymium:yttrium-aluminum-garnet laser, preserving the posterior capsule particularly in patients receiving multifocal intraocular lens implants, providing a viable solution for PCO in animals, and using it in developing countries that lack access to neodymium:yttrium-aluminum-garnet lasers. Perceived obstacles included potential lack of reimbursement by insurance companies, and the need for strong efficacy and safety profiles. Among adult surgeons, 70% (n = 31) indicated that preventative PCO therapy could add value to premium intraocular lens packages. Our studies revealed that cataract surgeons overwhelmingly support the development of preventative PCO therapy, and that clinical trials will play a critical role to test the safety and efficacy of specific therapeutic agents.

Effect of Novel Design Modifications on Fibrotic Encapsulation: An In Vivo Glaucoma Drainage Device Study in a Rabbit Model

Purpose

To quantify the effects of modified Ahmed glaucoma valves^® (AGV) with anti-fibrotic plate coatings or a plate surface micro-pattern on outflow resistance and tissue response.

Methods

Twelve New Zealand rabbits were divided into four groups: commercially available AGV implants (n = 3), AGV with hydrophilic coating (n = 3), AGV with heparin coating (n = 3), and AGV with a plate surface micro-pattern (n = 3). After 6 weeks, the anterior chamber silicone tube was cannulated in situ and perfused with 2.5 μL/min of saline. The pressures were recorded with a perfusion system to measure outflow resistance. The rabbits were then euthanized followed by enucleation of all eyes for bleb histological analyses.

Results

Hydrostatic pressures were significantly lower in AGVs with the hydrophilic plate coating (mean difference −9.6 mm Hg; p < 0.001), heparin-coated plates (mean difference −4.4 mm Hg; p < 0.001), and micro-patterned plates (mean difference −18.6 mm Hg, p < 0.001), indicating lower outflow resistance compared to control AGV models. Fibrotic encapsulation was lower in hydrophilic plate coating (84.2 μm; mean difference −6.2 μm, p = 0.425), micro-patterned surface (63.7 μm; mean difference −26.7 μm, p = 0.003), and heparin plate coating (49.3 μm; mean difference −41.1 μm, p = 0.006) when compared to control AGV models.

Conclusions

Modified AGVs with plate coatings and AGVs with micro-patterned plates both appear to reduce postoperative fibrotic encapsulation and aqueous outflow resistance by altering the tissue response to implanted materials. Further studies are needed to characterize the safety and role of plate surface modifications on glaucoma drainage devices.

Anti-Adhesive And Antiproliferative Synergistic Surface Modification Of Intraocular Lens For Reduced Posterior Capsular Opacification

BACKGROUND

Posterior capsular opacification (PCO) is the main complication after intraocular lens (IOL) implantation in cataract surgery, which is the result of lens epithelial cell (LEC) adhesion, proliferation and migration on the IOL and at the lens capsule interface. Hydrophilic surface modification, such as surface heparinization, decreases the cell adhesion, which has been commercialized and used clinically. However, clinical long-term observation results show no significant difference between the pristine and heparinized IOLs.

METHODS

To prevent PCO over the long time span, we modified the IOLs with an antiproliferative drug-loaded hydrophilic coating. The antiproliferative drug doxorubicin (DOX)-incorporated chitosan (CHI) nanoparticle was fabricated by sodium tripolyphosphate (TPP) gelation. Such antiproliferative drug-loaded CHI-TPP-DOX nanoparticles (CTDNP) were used as one of the building blocks to prepare polyelectrolyte multilayer with heparin (HEP) via layer-by-layer assembly, obtaining (HEP/CTDNP)n multilayers. The assembly process was characterized by quartz crystal microbalance with dissipation (QCM-D). The drug release behavior of the coating was investigated by ultra-HPLC (UPLC). In vitro cell experiments were carried out to monitor the effects of multifunctional coatings on cellular adhesion, proliferation and migration. And the intraocular implantation was performed on rabbits to evaluate the in vivo PCO inhibitory effect of such surface-functionalized IOLs.

RESULTS

The positively charged CTDNP was successfully prepared by ionic gelation. The QCM-D results indicate the successful preparation of the (HEP/CTDNP)n multilayer film. Drug release profiles showed that surface-multifunctionalized IOL had drug-sustained release properties. In vitro cell culture results showed significant inhibition of adhesion, proliferation and migration of LECs after surface modification. The in vivo results showed that the IOLs with multifunctionalized surface can effectively reduce the posterior hyperplasia and Soemmering's ring (SR) formation.

CONCLUSION

These findings suggested that such multifunctionalized drug-eluting IOLs can effectively reduce the posterior hyperplasia and SR formation when intraocular implantation has a major impact on reducing PCO incidence. Thus they have a great potential in improving patient vision recovery and maintenance.

Anti-Inflammatory Effects of Heparin and Its Derivatives: A Systematic Review

Background. Heparin, used clinically as an anticoagulant, also has anti-inflammatory properties. The purpose of this systematic review was to provide a comprehensive review regarding the efficacy and safety of heparin and its derivatives as anti-inflammatory agents. Methods. We searched the following databases up to March 2012: Pub Med, Scopus, Web of Science, Ovid, Elsevier, and Google Scholar using combination of Mesh terms. Randomized Clinical Trials (RCTs) and trials with quasi-experimental design in clinical setting published in English were included. Quality assessments of RCTs were performed using Jadad score and Consolidated Standards of Reporting Trials (CONSORT) checklist. Results. A total of 280 relevant studies were reviewed and 57 studies met the inclusion criteria. Among them 48 studies were RCTs. About 65% of articles had score of 3 and higher according to Jadad score. Twelve studies had a quality score > 40% according to CONSORT items. Asthma (n = 7), inflammatory bowel disease (n = 5), cardiopulmonary bypass (n = 8), and cataract surgery (n = 6) were the most studied disease condition. Forty studies use unfractionated heparin (UFH) for intervention; the remaining studies use low molecular weight heparin (LMWH). Conclusion. Despite the conflicting results, heparin seems to be a safe and effective anti-inflammatory agent; although it is shown that heparin can decrease the level of inflammatory biomarkers and improves patient conditions, still more data from larger rigorously designed studies are needed to support use of heparin as an anti-inflammatory agent in clinical setting. However, because of the association between inflammation, atherogenesis, thrombogenesis, and cell proliferation, heparin and related compounds with pleiotropic effects may have greater therapeutic efficacy than compounds acting against a single target.

Intraindividual aqueous flare comparison after implantation of hydrophobic intraocular lenses with or without a heparin-coated surface

PURPOSE

To assess the efficacy of a heparin-surface-modified (HSM) hydrophobic acrylic intraocular lens (IOL) (EC-1YH PAL) and the same IOL without heparin coating (EC-1Y-PAL) by the flare and cell intensity in the anterior chamber after uneventful cataract surgery.

SETTING

Department of Ophthalmology, Paracelsus Medical University Salzburg, Austria.

DESIGN

Comparative case series.

METHODS

Routine phacoemulsification with randomized implantation of an HSM IOL in 1 eye (HSM IOL group) and an uncoated IOL (uncoated IOL group) in the fellow eye was performed. Postoperative inflammation was assessed objectively using a laser flare-cell meter (FM-600) preoperatively as well as 1 day and 1 and 3 months postoperatively. Aqueous cells in the anterior chamber, distance visual acuities, and subjective manifest refraction were also evaluated at each visit.

RESULTS

One hundred eyes (50 patients) were enrolled. In both groups, the mean flare values increased significantly from preoperatively to 1 day postoperatively (P<.001) and nearly reached preoperative values by 3 months postoperatively. One day postoperatively, the mean flare value was statistically significantly lower in the HSM IOL group (14.92 photons per millisecond [ph/ms] ± 7.47 [SD]) than in the uncoated IOL group (mean 16.73 ± 7.81 ph/ms) (P=.04); there was no statistically significant difference between groups 1 and 3 months postoperatively (both P>.58). The HSM IOL group had a greater and quicker decrease in aqueous cells, reaching statistical significance 1 month postoperatively (P=.01).

CONCLUSION

The HSM IOL showed a significant lower inflammatory reaction in the early postoperative stage with a faster disappearance of inflammatory signs.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Effect of heparin coating of a foldable intraocular lens on inflammation and capsular bag performance after cataract surgery

PURPOSE

To evaluate the effect of a heparin-coated foldable intraocular lens (IOL) on postoperative flare in high-risk patients.

SETTING

Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Randomized clinical trial.

METHODS

This study included patients with diabetes mellitus (DM), pseudoexfoliation syndrome (PXF), or both scheduled for cataract surgery in both eyes. One eye received a coated IOL (Polylens EC-1YH PAL) and the other eye, an uncoated control IOL (Polylens EC-1Y PAL). Aqueous flare measurements were taken using a laser flare meter (FM-600, Kowa) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively. Visual acuity and anterior (ACO) and posterior (PCO) capsule opacification were assessed, and IOL centration and tilt were measured with a Purkinje meter.

RESULTS

Eighty eyes of 40 patients were included in the study; 64 eyes of 32 patients completed the study. The mean flare values (photons/ms) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively were 6.98 ± 3.71 (SD), 19.14 ± 18.90, 16.62 ± 25.33, 10.33 ± 9.70, 8.74 ± 4.64, respectively, with the coated IOL and 8.65 ± 5.73, 22.08 ± 16.23, 13.44 ± 13.71, 7.50 ± 4.11, and 7.03 ± 3.70, respectively, with the control IOL. No significant differences were found in flare, visual acuity, ACO, PCO, tilt, or centration between the coated IOL and the control IOL at any timepoint.

CONCLUSION

No significant differences in flare or capsule performance were found between the coated IOL and control IOL.

Cataract surgery in uveitis

Cataract surgery in uveitic eyes is often challenging and can result in intraoperative and postoperative complications. Most uveitic patients enjoy good vision despite potentially sight-threatening complications, including cataract development. In those patients who develop cataracts, successful surgery stems from educated patient selection, careful surgical technique, and aggressive preoperative and postoperative control of inflammation. With improved understanding of the disease processes, pre- and perioperative control of inflammation, modern surgical techniques, availability of biocompatible intraocular lens material and design, surgical experience in performing complicated cataract surgeries, and efficient management of postoperative complications have led to much better outcome. Preoperative factors include proper patient selection and counseling and preoperative control of inflammation. Meticulous and careful cataract surgery in uveitic cataract is essential in optimizing the postoperative outcome. Management of postoperative complications, especially inflammation and glaucoma, earlier rather than later, has also contributed to improved outcomes. This manuscript is review of the existing literature and highlights the management pearls in tackling complicated cataract based on medline search of literature and experience of the authors.

Cytokines in blood from septic patients interact with surface-immobilized heparin

When passing blood from septic patients through a column packed with surface heparinized beads, we were able to significantly reduce concentrations of the proinflammatory cytokine tumor necrosis factor (TNF)-alpha from initially very high levels. Passage of blood over nonheparinized beads did not affect the TNF levels. Meanwhile, concentrations of the regulated on activation, normal T-cells expressed, and secreted leukocyte activating cytokine (RANTES) remained unchanged following passage through the heparinized column, but rose significantly after passage through a column packed with the nonheparinized control beads. We conclude that surface heparinization may be a useful technique for selectively regulating the levels of heparin-binding cytokines from whole blood. This may have potential implications for the treatment of hyper-inflammatory conditions such as severe sepsis. Our data also suggests that surface activation and its associated inflammatory response may be avoided by using heparinization of the extracorporeal circuit.

The efficacy of an acrylic intraocular lens surface modified with polyethylene glycol in posterior capsular opacification

To investigate if the surface modification of intraocular lens (IOL) is efficient in the prevention of posterior capsular opacification (PCO), the acrylic surface of intraocular lens (Acrysof) was polymerized with polyethylene glycol (PEG-IOL). The human lens epithelial cells (1 x 10(4) cells/mL) were inoculated on PEG grafted or unmodified acrylic lenses for the control. The adherent cells on each IOL surface were trypsinized and counted. The every PEG-IOL was implanted in 20 New Zealand rabbits after removal of crystalline lens. The formations of PCO were checked serially through retroilluminated digital photography, and the severity scores were calculated using POCOman. The cell adherence patterns on each IOL were examined by scanning electron microscopy. As a result, the mean number of adherent cells of PEG-IOL (3.2+/-1.1 x 10(3)) tended to be smaller than that of the acrylic controls (3.6+/-1.9 x 10(3)) without a statistical significance (p=0.73). However, the mean severity of PCO formation in PEG-IOL was significantly lower than that in the control during the third to sixth weeks after surgery. Scanning electron microscopy revealed that the more patch-like cells were found firmly attached to the IOL surface in control than in the PEG-IOL. Conclusively, PEG polymerization to the acrylic IOL would possibly lessen the formation of PCO after cataract removal.

Improvement of the surface biocompatibility of silicone intraocular lens by the plasma‐induced tethering of phospholipid moieties

To improve the surface biocompatibility of the silicone intraocular lens (IOL), 2-methacryloyloxyethyl phosphorylcholine (MPC) was tethered onto the IOL through air plasma treatment. Chemical changes on the IOL surface were characterized by X-ray photoelectron spectroscopy (XPS) to confirm the covalent binding of MPC. Morphologies of the IOL surfaces were observed by scanning electron microscopy (SEM) to optimize the plasma treatment process. The hydrophilicity and biocompatibility of the control and modified IOLs were compared by the measurements of water contact angle, platelet adhesion, macrophage cell culture, and lens epithelial cell (LEC) attachment. It was found that, after the tethering of MPC, the hydrophilicity of the IOL can be improved significantly and permanently, and the platelet, macrophage, and LEC adhesion on the IOL surface are obviously suppressed, which indicated the enhancement of surface biocompatibility.

Effect of surface coating an acrylic intraocular lens with poly(2-methacryloyloxyethyl phosphorylcholine) polymer on lens epithelial cell line behavior

PURPOSE

To evaluate the effect of surface coating of an acrylic intraocular lens (IOL) with poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) on the behavior of the lens epithelial cell (LEC) line, alpha-TN4.

SETTING

Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan.

METHODS

A hydrophobic soft acrylic IOL (AF-1, Hoya) was coated with MPC polymer. A noncoated IOL served as control. An IOL from each group was placed on the membrane of collagen I or IV of the cell culture dish. The alpha-TN4 cells were seeded in the insert. Cell behaviors (ie, cell proliferation and spreading) on IOLs and membranes were observed. Cell migration beneath the IOL optic portion was assayed using a computer software program (POCOman system) for posterior capsule opacification (PCO). Type I or IV collagen is the major matrix component of PCO or native lens capsule.

RESULTS

Cell proliferation was more marked on the noncoated IOL than on the coated IOL. Type IV collagen accelerated proliferation more than type I collagen. Cell migration to the area beneath the IOL optic was more prominent in the group with the type I collagen membrane and noncoated IOL than in other groups.

CONCLUSION

Coating an acrylic IOL surface with MPC polymer suppressed adhesion and proliferation of LECs, suggesting it improves IOL biocompatibility.

Chemoattraction of inflammatory cells by various intraocular lens materials

PURPOSE

To compare the chemotactic activity induced by polymethyl methacrylate (PMMA), acrylic, and silicone intraocular lens (IOL) materials, regardless of the surgical and host factors.

METHODS

The chemotactic effect of five different IOLs was studied using a modified multi-well Boyden chamber. Two different non-coated PMMA IOLs, a heparin-coated PMMA IOL, an acrylic IOL, and a silicone IOL were assessed. Each mean migration distance of the IOLs was compared with the others using Student's t test.

RESULTS

All IOLs induced some amount of leukocyte chemotaxis. There was no statistically significant difference between the chemotactic activity of PMMA IOLs. However, chemotactic activity was significantly higher in acrylic (p<0.05) and silicone (p<0.05) IOLs compared to one of the PMMA lenses.

CONCLUSIONS

This limited study has proven that chemotaxis assay is a useful tool to assess the biocompatibility of IOLs. The IOL material itself might attract inflammatory cells to its surface in the absence of surgical and host factors. As PMMA IOLs do not cause an increase in inflammatory reaction, they may be considered safe to use. Further improvement in chemical composition and surface characteristics of IOLs should reduce the inflammatory reaction and increase the biocompatibility and safety of IOLs.

Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro

INTRODUCTION

Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes).

MATERIALS AND METHODS

In a pilot experiment, the effect of Dynasilan coating on the adherence of S. epidermidis was tested on glass slides. Forty-two Dynasilan-modified and 42 unmodified IOL (14 PMMA, 14 silicone and 14 hydrogel) were incubated at 37 degrees C in brain heart infusion broth (10(8) CFU/ml) with either S. epidermidis for 24 h or with P. acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3x45 s. After dilution series and incubation at 37 degrees C on Petri dishes for 24 h and 3 days, respectively, the colonies were counted.

RESULTS

In the pilot experiment, a markedly lower number of adherent S. epidermidis was observed on Dynasilan-modified glass slides. Of all IOL materials incubated with S. epidermidis, those modified with Dynasilan showed a lower mean number of adherent bacteria (mean 1.37x10(7); SD 2.37x10(7)) than those untreated (2.43x10(7); SD 3.04x10(7)). IOLs incubated with P. acnes showed a significantly lower mean number of adherent bacteria of 2.51x10(4) (SD 2.71x10(4)) on Dynasilan-modified IOLs versus 6.27x10(4) (SD 7.70x10(4)) on untreated IOLs.

CONCLUSION

The presented in vitro results indicate that Dynasilan surface modification is able to reduce the adherence of S. epidermidis and P. acnes on all IOL materials tested. Further studies regarding the stability of this modification and its biocompatibility must be performed.

Heparin in the intraocular irrigating solution in pediatric cataract surgery

PURPOSE

To investigate the antiinflammatory effects of adding heparin sodium to the irrigating solution to prevent fibrinoid reaction and related long-term complications after pediatric cataract surgery.

SETTING

Department of Ophthalmology, Inonu University, Turgut Ozal Medical Center, Malatya, Turkey.

METHODS

Thirty eyes of 18 children who had cataract or other ocular surgery were included in the study. Bilateral cataract surgery was performed in 20 eyes of 10 children and bilateral secondary intraocular lens (IOL) implantation in 4 eyes of 2 children (Group 1). Four eyes of 4 children had unilateral cataract surgery and 2 eyes of 2 children with previous perforating eye injury had synechiotomy and pupilloplasty (Group 2). Heparin sodium was added to the irrigating solution during surgery in 12 left eyes of children with bilateral surgery (Group 1a) and in all eyes in Group 2. Heparin sodium was not added during surgery in 12 right eyes of children having bilateral surgery (Group 1b, control). Early and late postoperative intraocular reactions were recorded and compared.

RESULTS

In Group 1a (heparin added), 6 eyes had less fibrinoid reaction and fewer related complications such as posterior synechias, pupil irregularity, and intraocular lens (IOL) decentration than the fellow right eyes. No eye in Group 1a having primary cataract surgery had hyphema or intraocular bleeding. Hyphema occurred on the first postoperative day in 1 eye in Group 1a that had secondary IOL implantation.

CONCLUSIONS

Adding heparin sodium to the irrigating solution decreased postoperative inflammatory and fibrinoid reactions and related complications such as synechias, pupil irregularity, and IOL decentration in pediatric cataract surgery. However, the use of heparin during surgery can be risky in eyes with a defective blood-aqueous barrier such as after previous ocular surgery.

Collamer intraocular lens implantation with active uveitis

Two patients with active iritis developed cataracts and had successful cataract surgery with implantation of a Collamer (Staar Surgical, AG) intraocular lens (IOL). Both patients developed severe bilateral uveitis, which in 1 patient was refractory to control. Different IOL materials have been used in iritis patients with varying degrees of success. The IOLs used in these patients remained free of cellular and noncellular deposits, such as those that frequently develop on the anterior surface of IOLs in uveitis patients. Two of the 3 eyes developed a secondary membrane that was successfully treated by a neodymium:YAG laser posterior capsulotomy.

Hydrophobic acrylic versus heparin surface-modified polymethylmethacrylate intraocular lens: a biocompatibility study

BACKGROUND

The implant of intraocular lenses (IOLs) following cataract surgery induces a foreign-body reaction to the IOL and a response on the part of the lens epithelial cells (LECs). The purpose of this study was to compare these aspects after the implantation of two different IOL materials.

METHODS

Thirty-six cataract patients were randomised to receive two different foldable lens: an acrylic hydrophobic IOL (Acrysof MA30BA) and a heparin surface-modified (HSM) polymethylmethacrylate IOL (Pharmacia & Upjohn 809C) after phacoemulsification. Slit-lamp biomicroscopy with specular technique was used to assess the inflammatory cell adhesion on the anterior IOL surface, anterior capsule opacification (ACO) and membrane growth from the rhexis edge at 7, 30, 90, 180 and 360 days after surgery.

RESULTS

The 809C group showed a higher percentage of patients with slight inflammatory cell adhesion on the anterior cell surface and a higher small cellular density during the whole follow-up period. The epithelioid cell response was greater in the 809C group than the Acrysof group but the difference between the two groups was not statistically significant. The ACO increased during the follow-up in both groups but was significantly higher in the 809C group.

CONCLUSION

Acrysof lenses are more biocompatible than HSM IOLs, showing a lower grade of inflammatory cell adhesion and ACO. The implantation of these lenses may be particularly indicated in patients with pathologies predisposing to blood-aqueous barrier damage.

Comparative performance of intraocular lenses in eyes with cataract and uveitis

PURPOSE

To evaluate the postoperative outcomes in uveitic eyes after phacoemulsification and posterior chamber intraocular lens (IOL) implantation.

SETTING

Multicenter (19) international study.

METHODS

This prospective randomized comparative interventional case series comprised 140 eyes of 140 patients who had phacoemulsification and implantation of IOLs of various materials: hydrophobic acrylic (n = 48), silicone (n = 44), poly(methyl methacrylate) (PMMA) (n = 26), or heparin-surface-modified PMMA (HSM PMMA) (n = 22). Preoperative and postoperative grading and control of intraocular inflammation were performed. Clinically significant observations, visual outcomes, and the incidence of postoperative complications were recorded.

RESULTS

At the final follow-up, 64 eyes (46.3%) had a best corrected visual acuity of 20/40 or better, an improvement that was highly significant (P <.0001). One day after surgery, the acrylic group had the lowest inflammation values and the silicone group the highest (P =.02). The acrylic group continued to have the lowest inflammation grade values until the 3-month follow-up. The acrylic and HSM PMMA groups had the lowest incidence of relapses. Posterior capsule opacification developed in 48 eyes (34.2%), with the highest incidence in the silicone group.

CONCLUSIONS

Phacoemulsification with IOL implantation in selected uveitic eyes was safe and effective. Acrylic IOLs provided a better visual outcome and lower complication rate than IOLs of other materials.

Avoiding complications in combined phacotrabeculectomy

Combined phacoemulsification and trabeculectomy offers the advantage of relieving both cataract and increased intraocular pressure in one surgical sitting. The procedure however entails greater risks than either alone. An approach to minimize these risks is described.

Inflammation after implantation of hydrophilic acrylic, hydrophobic acrylic, or silicone intraocular lenses in eyes with cataract and uveitis: comparison to a control group

PURPOSE

To compare the course of inflammation after small-incision cataract surgery with implantation of 1 of 3 types of foldable intraocular lenses (IOLs) in eyes with uveitis.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

Seventy-four eyes with uveitis and cataract and 68 control eyes with cataract were prospectively selected to receive a foldable hydrophilic acrylic (Hydroview, Bausch & Lomb), hydrophobic acrylic (AcrySof, Alcon), or silicone (CeeOn 911, Pharmacia) IOL. All surgery was performed by the same surgeon using a standardized protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag IOL implantation. Preoperative and postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 28, 90, and 180 days after surgery using the Kowa FC-1000 laser flare-cell meter. All uveitic eyes were in remission for at least 3 months before surgery.

RESULTS

In the uveitic eyes, there was no statistically significant difference in the postoperative course of flare and cell among the 3 IOL groups. Six months after surgery in uveitic eyes, flare values reached preoperative levels and the cell count was lower than preoperatively in all 3 IOL groups. Relative flare values were higher in the eyes with uveitis and a CeeOn 911 IOL; however, the difference between this group and the 2 acrylic IOL groups was not significant.

CONCLUSIONS

There were no significant differences in inflammation after implantation of foldable IOLs in uveitic eyes. Although absolute flare values and cell counts in eyes with uveitis were higher than in control eyes, primarily because of a damaged blood-aqueous barrier (BAB), BAB recovery was similar between the 2 groups. The changes in the BAB indicate that foldable IOL implantation is safe in uveitic eyes.

Uveal and capsular biocompatibility of 2 foldable acrylic intraocular lenses in patients with uveitis or pseudoexfoliation syndrome: comparison to a control group

PURPOSE

To evaluate the uveal and capsular biocompatibility of hydrophilic acrylic (Hydroview) and hydrophobic acrylic (AcrySof) intraocular lenses (IOLs) after phacoemulsification in eyes with pseudoexfoliation syndrome (PEX) or uveitis and compare the results with those in a control group.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective nonrandomized comparative trial comprised 143 eyes recruited consecutively. Of these, 49 eyes had PEX, 43 had uveitis, and 51 served as controls. A standardized surgical protocol was used. Cell reaction, anterior (ACO) and posterior (PCO) capsule opacification, and flare were evaluated 1 year after cataract surgery.

RESULTS

Regarding uveal biocompatibility, the number of foreign-body giant cells (FBGCs) increased in proportion to associated ocular pathologies in both IOL groups. The difference between the Hydroview control and Hydroview uveitis groups was statistically significant. The number of FBGCs was greater on AcrySof IOLs than on Hydroview IOLs in all 3 groups. The difference in FBGCs between the 2 IOL types was statistically significant in the control and PEX groups. Regarding capsular biocompatibility, lens epithelial cell (LEC) outgrowth was inversely correlated with intraocular inflammation. Outgrowth was statistically significantly higher with Hydroview IOLs, occurring in 85% in the control group, 45% in the PEX group, and 28% in the uveitis group (P <.0001). With AcrySof lenses, the percentages were 0%, 8%, and 4%, respectively. The PEX and uveitis groups were more likely to develop ACO than the control group (P <.012). There was no statistically significant difference in ACO between the 2 IOL types in the 3 patient groups. The PCO was statistically significantly greater in the uveitis group than in the control group (P <.026) and statistically significantly more dense on Hydroview than on AcrySof IOLs in all 3 patient groups (P <.002). Flare was statistically significantly higher in the uveitis group than in the PEX and control groups with both IOL types (P <.012). There was no statistically significant difference in flare between the 2 IOL types.

CONCLUSIONS

Uveal and capsular biocompatibility depends on the intensity of ocular inflammation. The greater the inflammation, the less the biocompatibility of hydrophilic and hydrophobic acrylic materials. AcrySof stimulated more FBGCs. The Hydroview material had better uveal but poorer capsular biocompatibility than AcrySof. The sharp optic edge effect of the AcrySof IOL and the advantages of the Hydroview lens in normal eyes are less apparent in compromised eyes.

Effect of heparin in the irrigation solution on postoperative inflammation and cellular reaction on the intraocular lens surface

PURPOSE

To evaluate the influence of heparin sodium in the irrigation solution on postoperative inflammation and cellular reaction on the anterior surface of a hydrophilic intraocular lens (IOL).

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This randomized prospective single-surgeon study included 50 patients with senile cataract only. Half the patients received 1 mL of heparin sodium (concentration 10 IU/mL) in addition to the regular irrigating solution. In all other respects, the procedure was standardized: clear corneal incision, phacoemulsification, and implantation of a Hydroview foldable hydrogel IOL (Bausch & Lomb). The parameters of inflammation-anterior chamber flare and cells-were evaluated with the pupil dilated in a masked fashion using a Kowa FC-1000 laser flare-cell meter 1, 3, 7, 14, and 28 days and 3, 6 and 12 months postoperatively. The cellular reaction was semiquantitatively examined and analyzed by specular microscopy.

RESULTS

In both groups, flare and cell values increased on the first postoperative day and successively decreased thereafter. In the first week, the flare and cell values were significantly higher in the group without heparin sodium in the irrigating solution. Subsequently, there were no differences between the 2 groups in flare or cells. At 1 day, the heparin sodium group had statistically significantly fewer IOLs with no cells on the surface. Subsequently, no differences in cellular reaction on the IOL were observed.

CONCLUSIONS

Heparin sodium added to the standard irrigating solution reduced disturbances of the blood-aqueous barrier in the early postoperative period. There seemed to be no long-term effect, especially on cellular reaction, on the hydrophilic IOL surface.

Physicochemical surface properties of various intraocular lenses

PURPOSE

It is of major interest to understand how intraocular lens (IOL) surfaces interact with aqueous humor or tissues after implantation. Important parameters to describe the physicochemical surface properties are the contact angle and critical surface tension. Therefore, we performed measurements of the contact angle and critical surface tension of several commercially available IOLs.

SETTING

Department of Ophthalmology, Johannes Gutenberg University, Mainz, University Eye Hospital, Tübingen, and Max Planck Institute for Polymer Research, Mainz, Germany.

METHODS

A total of 17 commercially available standard quality IOL types (6 of each) of different materials from several manufacturers were studied. Scanning electron microscopy and contact angle measurements using the sessile drop method were made.

RESULTS

The sessile drop method differentiated all materials based on their surface forces. The contact angle (mean +/- SD) ranged from 56.5 +/- 3.8b 3.

CONCLUSION

Contact angles differed between the IOLs depending on the IOL material with the lowest contact angle in the heparin-surface-modified IOL. The contact angle measurement method generates useful information about the material surface and its potential biomaterial interactions.

Effect of heparin surface modification in reducing silicone oil adherence to various intraocular lenses

PURPOSE

To evaluate surface properties of various intraocular lenses (IOLs), including a newly fabricated heparin-surface-modified (HSM) silicone IOL, with special reference to their efficiency in reducing potential silicone oil adherence to the IOL optics.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Five groups of rigid and foldable IOLs were analyzed in an in vitro test for the percentage of silicone oil adherence: a single-piece foldable hydrophilic-acrylic IOL (n = 9); a single-piece rigid poly(methyl methacrylate) (PMMA) IOL with HSM coating of the lens optic (n = 9); a 3-piece foldable silicone optic IOL with HSM coating of the optic (n = 10); a single-piece standard rigid PMMA IOL (n = 7); and a standard 3-piece foldable silicone optic IOL (n = 9). After the IOLs were immersed in water and then in silicone oil, gross photographs taken. Image analysis was performed to evaluate the percentage of silicone oil coverage of the anterior and posterior surfaces of each IOL optic.

RESULTS

The mean silicone oil coverage of the hydrophilic-acrylic IOLs was 5.6% +/- 2.5% (SD); of the HSM PMMA IOLs, 6.2% +/- 4.3%; of the HSM silicone optic IOLs, 6.7% +/- 3.2%; and of the standard PMMA IOLs, 20.3% +/- 13.3%. The mean silicone oil coverage was greatest on the standard silicone optic IOLs, 98.2% +/- 3.1%.

CONCLUSIONS

Intraocular lenses with a hydrophilic optic have less tendency toward adherence to silicone oil than more hydrophobic designs. A foldable silicone IOL with heparin surface modification can significantly reduce potential silicone oil adherence, comparable to the level achievable with the rigid HSM PMMA designs. Two new foldable IOL styles, the HSM silicone IOL and IOLs in the general class of hydrophilic-acrylic, were highly efficacious in reducing silicone oil adherence. There is now a real choice of foldable lenses for patients with actual or potential vitreoretinal diseases.

Multifocal intra-ocular lenses

Multifocal intra-ocular lenses (IOLs) are designed to overcome the lack of accomodation to provide useful distance and near vision. Reduced contrast sensitivity has been reported. Refractive IOLs produce two or more focal points depending on the refractive power of the portion of the lens crossed by the light. Diffractive IOLs are strictly bifocal; each point of the lens can create both a distance and near focus. Several clinical investigations show that multifocal IOLs can be used as an alternative to monofocal lenses. However, patient selection, realistic expectations, and adequate control of surgical procedures are necessary.

Control of intra-ocular inflammation associated with cataract surgery

Postoperative ocular inflammation following cataract surgery is related to the risk of complications like corneal edema, intraocular pressure spikes, cystoid macular edema, and posterior capsule opacification. The degree of postoperative inflammation following cataract surgery is linked to several surgery-dependent factors such as surgical technique, intraocular lens type, and also patient-dependent factors such as history of inflammatory disease and degree of iris pigmentation. During the past decade, major advances have occurred in cataract surgery techniques, equipment, and pharmacologic strategies that decrease the degree of postoperative inflammation following cataract surgery and reduce patients' risk for inflammation-related complications. This article reviews the most recent literature regarding the control of cataract surgery-induced intra-ocular inflammation.