Heparin-surface-modified Intraocular Lens Research Articles

Comparison of Clinical Outcomes of Implantation of Foldable Hydrophobic Acrylic Intraocular Lens With and Without Heparin Surface Modification in Indian Diabetic Patients.

Background This study aimed to compare the clinical outcomes of a heparin surface-modified (HSM) hydrophobic acrylic foldable intraocular lens (IOL) (CT LUCIA 601PY) and non-heparin-modified hydrophobic acrylic foldable IOL (AcrySof IQ SN60WF) in diabetic patients undergoingphacoemulsification. Methodology Thisrandomized, single-surgeon, double-masked controlled trial was conducted at Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi. In this randomized controlled trial, 100 eyes of 100 diabetic patients with or without mild-to-moderate diabetic retinopathy were enrolled (HSM IOL, n = 50; non-HSM IOL, n = 50). Outcome measures were aqueous flare, visual acuity, and anterior chamber depth (ACD). These were measured preoperatively as well as one day, one week, one month, three months, six months, and one year postoperatively. Results The HSM IOL group had significantly lower anterior chamber aqueous flare values (photon count/ms) than the non-HSM IOL group on postoperative day one (9.97 ± 5.2 vs. 17.56 ± 11.3, p < 0.001), postoperative week one (11.47 ± 7.78 vs. 17.06 ± 9.4, p = 0.02), and postoperative month three (7.7 ± 4.1 vs. 12.5 ± 5.6, p = 0.004) of phacoemulsification. The corrected distance visual acuity (CDVA) was significantly better in the HSM IOL group on postoperative day one (uncorrected distance visual acuity: p = 0.022; CDVA; p = 0.005), but there was no significant difference at any other follow-ups. ACD was significantly longer in the HSM IOL group at all follow-ups. Conclusions Theimplantation of HSM IOL resulted in significantly lower inflammatory reactions in the early postoperative period in diabetics.

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

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. Department of Ophthalmology, Paracelsus Medical University Salzburg, Austria. Comparative case series. 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. 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). The HSM IOL showed a significant lower inflammatory reaction in the early postoperative stage with a faster disappearance of inflammatory signs. No author has a financial or proprietary interest in any material or method mentioned.

Outcomes of Cataract Surgery in Patients With Uveitis: A Systematic Review and Meta-analysis

To critically assess the evidence base regarding outcomes following cataract surgery in uveitic cases. Systematic evidence-based review and meta-analysis. A comprehensive search query was performed on MEDLINE, EMBASE, CINHAL, and CENTRAL databases. Relevant publications were identified by reviewing query results and reference list searches. A total of 89 articles met eligibility criteria. Among uveitic eyes with quiet or mostly quiet uveitis before cataract surgery, 20/40 visual acuity or better (≥20/40) was achieved in 68% following phacoemulsification, 72% following extracapsular cataract extraction, and 40% following pars plana lensectomy. More eyes undergoing cataract surgery with intraocular lens (IOL) implantation than eyes left aphakic achieved ≥20/40 postoperatively (71% vs 52%). Eyes receiving acrylic IOLs or heparin-surface-modified (HSM) polymethylmethacrylate had better visual outcomes than those receiving non-HSM polymethylmethacrylate or silicone IOLs. Active uveitis at the time of cataract surgery was associated with worse visual outcomes. Compared with other uveitis cases, the proportion achieving 20/40 or better post cataract surgery was better for Fuchs heterochromic cyclitis cases and worse for uveitis related to Behçet disease, Vogt-Koyanagi-Harada disease, or sympathetic ophthalmia, and also posterior uveitis in general. Cataract surgery in eyes with uveitis resulted in normal range levels of visual acuity in most cases. The review suggests that preoperative control of uveitis, use of an acrylic or HSM IOL, and a diagnosis of Fuchs heterochromic cyclitis were associated with better outcomes. Posterior-involving uveitides tended to do worse, likely because of vision-limiting complications of uveitis. Average results may not be applicable to specific clinical scenarios.

Exfoliation syndrome and heparin surface modified intraocular lenses

Either heparin surface modified (HSM) or regular polymethyl methacrylate (PMMA) intraocular lenses (IOLs) were implanted after extracapsular cataract extraction in 40 human eyes with exfoliation syndrome in a double-masked, randomized study. The patients were investigated preoperatively, and then 1 day, 1 week, 3, 6 and 12 months postoperatively. In eyes implanted with the HSM IOL, 26% had a fibrinoid reaction anterior to the IOL, while this complication was found in 50% of eyes implanted with the regular IOL. Pigment and cell deposits were more frequent on the regular IOLs than on the HSM lenses postoperatively. Posterior synechia formation between the iris and the implant or lens capsule was more common in the eyes with regular IOL compared to HSM IOL. No difference in visual acuity between the two groups was found either before or after surgery. The results suggest that in eyes with exfoliation syndrome, a heparin surface modified IOL reduces clinical complications associated with cataract surgery.

Long-term visual results of bifocal intraocular lens implantation

Purpose To evaluate the long-term visual results and variability in contrast sensitivity in patients with heparin-surface-modified (HSM) diffractive bifocal intraocular lenses (IOLs). Setting Institute of Ophthalmology, University of Catania, Italy. Methods In this prospective study, visual acuity (distance and near) and contrast sensitivity were measured in 35 patients who had phacoemulsification with bifocal diffractive IOL (model 811E, Pharmacia) implantation. Patient satisfaction was also evaluated using a questionnaire. Mean follow-up was 20 months (range 18 to 24 months). Results At the last examination, mean distance visual acuity was 0.79 ± 0.2 (SD) without correction and 1.0 ± 0.15 with best correction. Mean uncorrected near visual acuity was J1.6 ± J0.77 and with best distance correction, J1.19 ± J0.49. No statistically significant changes in visual acuity were evident at the last follow-up (Student t test). No changes were found in contrast sensitivity reduction over time, nor were late postoperative complications noted. Overall patient satisfaction was rated as good by 94.3% of patients with best distance correction. Conclusions The diffractive bifocal HSM IOL provided good visual performance for distance and near over time. In relation to the low rate of postoperative complications, the slight contrast sensitivity reduction was stable during follow-up.

Heparin surface-modified intraocular lenses in patients with inactive uveitis or diabetes

Objective This study aimed to determine whether heparin surface-modified (HSM) intraocular lenses (IOLs) with a hydrophilic surface would reduce cell adherence and other postoperative changes compared with the conventional polymethylmethacrylate (PMMA) IOLs in patients with either diabetes mellitus or inactive uveitis. Design The study design was a randomized, double-masked, clinical trial. Participants Twenty-five patients with bilateral cataracts, 14 with inactive anterior uveitis and 11 with diabetes, with an age range of 11 to 81 years (mean, 52.8 years) participated. Intervention Bilateral cataract extraction with posterior chamber IOL implantation was measured, each patient receiving an HSM lens in one eye and a PMMA lens in the other. Pharmacia one-piece HSM and PMMA IOLs were used. Postoperative ocular changes were evaluated at regular intervals for 24 months in patients with inactive uveitis and for 6 months in patients with diabetes. Patients and physicians alike were unaware of which eye contained which lens until postoperative results were compiled. Records were kept by a study coordinator. Main outcome measures Comparisons of posterior synechiae, IOL cellular deposits, and posterior capsular fibrosis between PMMA and HSM IOLs were measured. Results Using the chi-square test, no statistically significant difference was found between the HSM and PMMA IOLs in the number of cellular deposits found on the anterior IOL surface, the number of adhesions between the iris and IOL, or the incidence of capsular opacification. Conclusion The HSM and PMMA IOLs showed similar postoperative results in patients with inactive uveitis or diabetes mellitus.

Biocompatibility and blood-aqueous barrier impairment in at-risk eyes with heparin-surface-modified or unmodified lenses

Purpose: To evaluate the influence of heparin-surface-modified (HSM) versus unmodified poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) on the blood-aqueous barrier (BAB) in at-risk eyes.Setting: Department of Ophthalmology, Bundesknappschaft's Hospital, Sulzbach, Germany.Methods: This study comprised 100 patients with predisposing risk factors for BAB destabilization (e.g., diabetes mellitus with or without retinopathy, glaucoma, pseudoexfoliation, uveitis). One eye in each patient received an HSM IOL and the fellow eye, a conventional unmodified PMMA IOL after phacoemulsification by the same surgeon. Anterior chamber flare was measured with the Kowa 500 laser flare meter 1 day before and 1 day, 1 and 6 weeks, and 3 months after surgery.Results: For most risk factors, mean flare was lower in the HSM group than in the PMMA group at most follow-ups. Significantly lower flare values (difference between postoperative and preoperative mean values) were seen in eyes with the HSM IOL at 6 weeks (P < .004) and 3 months (P < .003; Student's t-test). In the group with preoperative elevated flare values, the eyes with the HSM IOL had significantly better results 6 weeks (P < .0006) and 3 months (P < .01) postoperatively. The values in the HSM IOL eyes were also significantly higher in the diabetic with retinopathy group at 3 months (P < .003).Conclusion: The results confirm the efficacy of IOL surface modification in reducing postoperative intraocular reaction in at-risk eyes.

After-cataract formation in newborn rabbits implanted with intraocular lenses

Purpose: Comparison of the after-cataract formation in newborn rabbits implanted with a heparin-surface-modified (HSM) intraocular lens (IOL), a silicone IOL, or no IOL.Methods: Two groups of 3-week-old rabbits were used. In Group 1 (n = 11), lensectomy was performed in both eyes. One eye was selected at random and an HSM IOL was implanted in the capsular bag; the other eye was left aphakic. In Group 2 (n = 13), lensectomy was performed in both eyes. An HSM IOL was implanted in one eye, a silicone IOL in the other. The wet mass of the dissected after-cataract was determined 3 months after surgery in both groups.Results: In Group 1, the wet mass of the dissected after-cataract was 17.0 ± 6.5 mg (mean ± SEM) in eyes implanted with an HSM IOL and 159.7 ± 17.0 mg in aphakic eyes. This difference was statistically significant (P < .01). In Group 2, the wet mass of the dissected after-cataract was 18.3 ± 4.3 mg in eyes implanted with an HSM IOL and 25.7 ± 5.2 mg in eyes implanted with a silicone IOL. No statistically significant difference was found.Conclusions: In young rabbits, implantation of an IOL in the capsular bag following lensectomy reduced cell proliferation.

Effect of heparin-surface-modified poly(methyl methacrylate) intraocular lenses on the postoperative inflammation in an Asian population

Purpose: To compare the efficacy of heparin-surface-modified (HSM), poly(methyl methacrylate) (PMMA) posterior chamber intraocular lenses (IOLs) with that of unmodified PMMA IOLs in reducing postoperative complications caused by inflammatory reactions after extracapsular cataract extraction in an Asian population.Setting: Departments of Ophthalmology, University of Malaya, Kuala Lumpur, Malaysia, and Tan Tock Seng Hospital, Singapore.Methods: In a randomized, double-blind study performed at two centers, 51 patients received an HSM PMMA lens and 48, an unmodified PMMA IOL. Cell and pigment deposits were evaluated by slitlamp at 1 to 6 days, 2 to 3 weeks, and 3 to 6 months postoperatively.Results: Significantly more eyes with unmodified IOLs had inflammatory cell deposits than those with HSM IOLs at 3 to 6 months (P < .001) and 12 to 14 months (P = .018) postoperatively. The HSM group also had significantly fewer cell deposits per patient at these two follow-ups. Significantly more eyes in the non-HSM group had pigment deposits 3 to 6 months after surgery (P = .049). One year postoperatively, about 85% of patients in both groups had a best corrected visual acuity of 0.5 or better.Conclusion: Heparin surface modification significantly reduced the inflammatory response to PMMA IOLs in an Asian population for at least 12 to 14 months.

Decreased prostaglandin E2 synthesis by lens epithelial cells cultured on heparin-surface-modified poly(methyl methacrylate)

Purpose: To evaluate whether heparin surface modification reduces prostaglandin E2 (PGE2) synthesis by lens epithelial cells (LECs) after intraocular lens (IOL) implantation.Setting: Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.Methods: The prostaglandin E2 (PGE2) concentration was determined in an incubation medium of human cataract LECs cultured on heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) plates at 1, 2, 3, and 4 weeks of culture. A medium without heparin served as a control.Results: The PGE2 concentration was significantly lower in the HSM than in the control medium at 3 and 4 weeks of culture.Conclusion: The results are consistent with the clinical observation of significantly decreased inflammation in eyes with HSM IOLs, indicating that such modification increases PMMA's biocompatibility with LECs. J Cataract Refract Surg 1996, 22:859-862

Heparin Surface-modified IOLs Compared with Regular PMMA IOLs in Patients with Diabetes and/or Glaucoma — 1 year Results of a Double-Blind Randomized Multi-independent Trial

OBJECTIVE: The objective of the study was to compare the inflammatory reaction following cataract surgery in patients with diabetes and/or glaucoma implanted with heparin surface modified (HSM) or PMMA intraocular lenses (IOLs). Specular microphotography and slit lamp evaluation were used to determine the presence of foreign body giant cells and cellular deposits on the IOL surface. The presence of capsular fibrosis, pigment and fibrin or fibrinlike deposits determined by slit lamp were secondary efficacy variables. STUDY DESIGN: The study was performed as a prospective, randomized, double-blind, multi-independent clinical trial with 1 year follow-up. PATIENTS: The study comprised 239 patients with diabetes and/or glaucoma. Of these patients, 122 had diabetes, 103 patients had glaucoma, and 14 patients had both diabetes and glaucoma. The mean age of the patients was 73 (± 9.8) years. RESULTS: At all visits, including the 1 year visit, there was a statistically significant difference in favour of HSM with a lower percentage of patients having giant cells on the IOL surface in the HSM group. Cellular deposits, seen with the slit lamp, were also found in significantly fewer patients in the HSM group at all follow-up visits except at 1 week. Visual acuity, at 1 year, was ≥ 0.5 (20/40) in 72% of the HSM group and in 84% of the PMMA group. The reason for a visual acuity below 0.5 was in most cases related to preoperative pathologies, especially in the diabetic patients in the HSM group. CONCLUSION: The results of this study indicate that heparin surface modification increases the biocompatibility of PMMA IOLs by significantly reducing the postoperative foreign body reaction for at least 1 year following cataract surgery in patients with diabetes and/or glaucoma.

Alterationen der Heparinbeschichtung auf Intraokularlinsen durch Implantationsinstrumente

In the last years heparin surface-modified intraocular lenses (HSM IOLs) were used for special indications like uveitis, synechia, congenital cataract or pseudoexfoliation syndrome. A monolayer of heparin molecules on the surface of PMMA-IOLs causes a reduced postoperative inflammatory reaction and produces a higher long-term biocompatibility than PMMA-IOLs without surface-modification. The study was designed to evaluate the possible damage of this heparin-monolayer on the PMMA-IOL by different metallic implantation forceps and different grasp-pressure. Different implantation instruments were used to grasp HSM and conventional PMMA-IOLS. We designed a new device to generate and measure the pressure by the implantation forceps on the IOL in online-mode. After staining the heparin-monolayer with toluidin blue the surface alterations on the intraocular lenses were examined for surface alterations, especially of the heparin-monolayer, by light and scanning electron microscopy subsequently. Implant forceps produced defects of the heparin layer and the PMMA-material. Each implantation forceps induced a specific pattern of destructed heparin surface in the grasp area. These defects showed high correlation with the pressure and the morphology of the forceps as shown by light and scanning electron microscopy. Mechanical irritation during the implantation procedure destroyed the heparin layer on PMMA-IOLs in the grasp-area. Clinical consequences are not yet known, but possible. An instrument with rounded, soft and smooth grasp-surface is required for implantation of HSM IOLs to avoid surface alterations, so that the patients get maximum profit by the heparin-modification.

Cataract surgery in children with capsulorhexis of anterior and posterior capsules and heparin-surface-modified intraocular lenses

Cataract surgery was performed in 21 eyes in 14 children (one to 12 years, 5.6 ± 4.0 [mean ± SD]). Cataract surgery was standardized and included capsulorhexis of the anterior capsule, irrigation/aspiration of the nucleus and cortex, puncture of the posterior capsule, injection of sodium hyaluronate (Healon GV®, 14 mg/ml) between the posterior capsule and the vitreous, and capsulorhexis of the posterior capsule. At the end of the procedure, a heparin-surface-modified (HSM) poly(methyl methacrylate) intraocular lens (IOL) was implanted in the capsular bag. Follow-up ranged from four to 16 months. No complications such as the appearance of vitreous in the anterior chamber occurred during surgery. A mild postoperative inflammation was seen in all cases. Opacification of the visual axis was seen in one eye ten months after surgery. Posterior synechial formation was seen in one eye. Our results suggest that capsulorhexis of the anterior and posterior capsules with implantation of an HSM IOL in the capsular bag is a safe procedure in children and produces good postoperative results.

Cell Attachment to Standard and Surface-modified Intraocular Lenses

OBJECTIVE: to undertake a comparative study of cell attachment to standard polymethyl methacrylate (PMMA) intraocular lenses (IOLs) and to two types of surface-modified IOLs ( heparin surface-modified and surface passivated ) using in-vitro techniques. STUDY DESIGN: All IOLs were preincubated in either saline, 20% foetal calf serum, bovine aqueous or bovine vitreous for 48 hours. Following preincubation to these biological fluids, the IOLs were exposed to cultured bovine Tenon's capsule fibroblasts for 24 hours and the number of cells attached to each IOL determined. RESULTS: Results determined substantial cell attachment to both standard PMMA IOLs and surface-passivated IOLs. By contrast, cell attachment to heparin surface-modified IOLs was reduced by between 84 and 95% when compared to the other IOL types ( P surface passivated IOLs, irrespective of the preincubation regime, was normal whereas the cells on the heparin surface-modified IOLs tended to be more rounded and exhibited less prominent cytoplasmic projections. CONCLUSIONS: This study demonstrates that surface-passivated IOL material has no additional properties, superior to standard PMMA, with regard to resistance to cell attachment and is significantly inferior to that of heparin surface-modified IOLs in this area. This simple and applicable method with which to evaluate the probability of cell deposition on intraocular prosthetic implants offers a valuable primary screening technique for new IOLs prior to animal or clinical studies.

Heparin surface modified intraocular lenses in uveitis

A retrospective analysis of the results of cataract surgery using heparin surface modified intraocular lenses (HSM-IOL) performed on patients with uveitis between August 1989 and July 1993 was undertaken. In total, 32 eyes of 28 patients with various types of uveitis underwent extracapsular cataract extraction and implantation of a posterior chamber HSM-IOL. In four patients, cataract extraction was combined with trabeculectomy. The post-operative follow-up period ranged from two to 51 months (average 16 months). The visual acuity improved in 31 of 32 eyes (96.8%) with 28 eyes (87.5%) seeing 6/18 or better. In four eyes (12.5%), the visual acuity was only 6/60 due to longstanding, pre-operative cystoid macular oedema. Posterior synechiae developed in eight eyes (25%), inflammatory deposits were noticed on the IOL surface in five eyes (15.6%), and three eyes (9.3%) required YAG laser posterior capsulotomy. These results suggest that HSM lenses are associated with minimal post-operative complications and appear safe to be used in human uveitic eyes.

Incidence of posterior capsule opacification in eyes with exfoliation syndrome and heparin-surface-modified intraocular lenses

Conventional poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) and heparin-surface-modified (HSM) IOLs were implanted after extracapsular cataract extraction in 40 human eyes with exfoliation syndrome. The study was doublemasked and randomized. Two years after surgery 17 cases with HSM IOLs and 15 with PMMA IOLs were examined. We observed that pigment and cell deposits were more frequent on the PMMA than on the HSM IOLs. The incidence of posterior synechia formation was similar in both groups. However, the incidence of neodymium:YAG laser posterior capsulotomy and posterior capsule opacification was more frequent in the PMMA IOL group. Visual acuity did not differ between the two groups before or two years after surgery. The results suggest that in eyes with exfoliation syndrome, implanting an HSM IOL reduces the incidence of posterior capsule opacification often associated with extracapsular cataract extraction.

Carbonic anhidrase inhibition and level of zinc in aqueous humor and blood

Purpose: To evaluate the influence of heparin-surface-modified (HSM) versus unmodified poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) on the blood-aqueous barrier (BAB) in at-risk eyes.Setting: Department of Ophthalmology, Bundesknappschaft's Hospital, Sulzbach, Germany.Methods: This study comprised 100 patients with predisposing risk factors for BAB destabilization (e.g., diabetes mellitus with or without retinopathy, glaucoma, pseudoexfoliation, uveitis). One eye in each patient received an HSM IOL and the fellow eye, a conventional unmodified PMMA IOL after phacoemulsification by the same surgeon. Anterior chamber flare was measured with the Kowa 500 laser flare meter 1 day before and 1 day, 1 and 6 weeks, and 3 months after surgery.Results: For most risk factors, mean flare was lower in the HSM group than in the PMMA group at most follow-ups. Significantly lower flare values (difference between postoperative and preoperative mean values) were seen in eyes with the HSM IOL at 6 weeks (P < .004) and 3 months (P < .003; Student's t-test). In the group with preoperative elevated flare values, the eyes with the HSM IOL had significantly better results 6 weeks (P < .0006) and 3 months (P < .01) postoperatively. The values in the HSM IOL eyes were also significantly higher in the diabetic with retinopathy group at 3 months (P < .003).Conclusion: The results confirm the efficacy of IOL surface modification in reducing postoperative intraocular reaction in at-risk eyes.