Heparin-surface-modified intraocular lens implantation in eyes with pseudoexfoliation syndrome

Exploring anterion capsular contraction syndrome in cataract surgery: insights into pathogenesis, clinical course, influencing factors, and intervention approaches

Anterior capsular contraction syndrome (ACCS) is a challenging complication that can occur following phacoemulsification cataract surgery. Characterized by capsular bag wrinkling, intraocular lens (IOL) decentration and tilt, ACCS can have negative effects on visual outcomes and patient satisfaction. This review aims to investigate the pathogenesis, clinical course, influencing factors, and intervention approaches for ACCS after cataract surgery. By understanding the underlying mechanisms and identifying factors that contribute to ACCS, surgeons can enhance their ability to predict and manage this complication. Various intervention strategies are discussed, highlighting their importance in reducing complications and improving surgical outcomes. However, further research is needed to determine optimal prevention and management strategies through long-term follow-up and comparative analyses. Advancements in this field will ultimately lead to improved visual outcomes and optimized cataract surgery for patients.

Intraoperative and Immediate Postoperative Outcomes of Cataract Surgery using Phacoemulsification in Eyes with and without Pseudoexfoliation Syndrome

BACKGROUND

To compare the intraoperative and immediate postoperative behavior and complications in eyes with pseudoexfoliation (PEX) syndrome with eyes having senile cataract without PEX during cataract surgery using phacoemulsification (PKE).

MATERIALS AND METHODS

In this prospective study, 68 eyes of 68 patients were divided into two groups: Group 1 (test) comprised 34 eyes with immature senile cataract with PEX and Group 2 (control) included 34 eyes with immature senile cataract without PEX and any coexisting ocular pathology. Phacoemulsification (modern cataract surgery) was performed on both groups through stop and chop technique and comparative analysis of the incidence of intraoperative and immediate postoperative complications was made.

RESULTS

There was no significant difference in rates of intraoperative complications between PEX (2.9%) and Control (0%) group. The mean pupil diameter was significantly smaller in Group 1 (p<0.001). No eye in either group had phacodonesis. 58.8% of eyes in Group 1 and 29.4% in Group 2 had a harder cataract (nuclear sclerosis) ≥ grade 3 (p=0.017). PKE was performed in all eyes with cataract in both groups. Intraoperative complication (zonular dialysis (dehiscence) was encountered in only 2.9% (1 case) of eyes with PEX. PC (posterior capsule) tear (rent) with vitreous loss was seen in 2.9% eyes of Group 1 and none in Group 2. Postoperatively, IOP (intraocular pressure) and aqueous flare response were comparable between the groups. Significantly higher inflammatory cell response was observed in Group 1 (p=0.014). BCVA (best corrected visual acuity) using Snellen chart with pinhole on postoperative day1 was significantly better in the control group compared to the group with PEX (p=0.027).

CONCLUSION

Phacoemulsification can be safely performed by experienced hands in cataractous eyes with PEX. The incidence of intraoperative and immediate post-operative complications in eyes with PEX was not significantly different compared to eyes without PEX in our study. Further studies among a larger population are required.

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.

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.

Pseudoexfoliation syndrome: pathological manifestations of relevance to intraocular surgery

Pseudoexfoliation syndrome (PEX) is a common ocular condition often associated with the need for intraocular surgery. Although results of cataract and glaucoma filtering surgery in eyes with PEX in the early stages of the disease may be comparable to those in eyes without PEX, in the later stages morbidity is significantly increased due to periocular surgical complications and the outcome is worse. Surgical and postoperative difficulties are often multifactorial and are directly related to the pathological changes of PEX on intraocular structures. Recent years have seen a large increase in the understanding of the effects of PEX on the various ocular tissues. Although the visible areas of the anterior capsule are most obviously involved, this is only a small part of the picture and of least significance. Biomicroscopically invisible changes of the zonules and their attachments are of greatest consequence. There is also distinct, often active, involvement of almost all tissues of the anterior segment of the eye, many of which have important implications for the anterior segment surgeon including iridopathy, iris vasculopathy (including persistent breakdown of the blood-aqueous barrier and anterior segment hypoxia), ciliary body involvement and keratopathy. Trabecular dysfunction is evident by the deposition of PEX material derived from both in situ and extra-trabecular production as well as protein and melanin deposition. These changes should be kept in mind by all intraocular surgeons as a source of potential difficulties in the perioperative period. Additionally, in light of these changes, patients need to be given realistic expectations regarding the increased risk of complications and more prolonged expected recovery time. In this short review, current reports relating to PEX pathological changes of practical interest to the intraocular surgeon are summarized.

Pseudoexfoliation in a rural population of southern India: the Aravind Comprehensive Eye Survey

PURPOSE

To determine the prevalence and risk factors for pseudoexfoliation in a rural population of southern India.

DESIGN

A population-based cross-sectional study of pseudoexfoliation with and without glaucoma in rural southern India.

METHOD

A total of 5,150 subjects aged 40 years and older from 50 clusters representative of three southern districts of Tamil Nadu in southern India.

RESULTS

All participants had a comprehensive eye examination at the base hospital, including visual acuity using logarithm of minimal angle of resolution (logMAR) illiterate E charts and refraction, slit-lamp biomicroscopy, gonioscopy, applanation tonometry, dilated fundus examinations, and automated central 24-2 full-threshold perimetry. Pseudoexfoliation (PXF) was diagnosed by the presence of typical white deposits on the anterior lens surface; additional sites included the cornea, iris, anterior vitreous face, posterior capsule, and intraocular lens in cataract-operated eyes and changes in the angle determined through gonioscopy, including increased pigmentation, PXF deposition, and PXF material within the angle.

CONCLUSIONS

The prevalence (95% confidence interval) of PXF was 6.0% (5.3, 6.6). The prevalence increased with age (P <.001) and was greater in males (P =.01). Of subjects with PXF, 25.7% remained bilaterally blind after best correction; 89.3% of this bilateral blindness was the result of cataracts. The prevalence of glaucoma among subjects with PXF was 7.5%; exfoliation was present in 26.7% of those identified as primary open-angle glaucoma. On multivariate analysis, increasing age and male gender were significantly associated with PXF. Pseudoexfoliation appears to be a relatively common disorder in older individuals in southern India. Ophthalmologists in India may wish to focus on the detection of PXF, especially considering the relatively large burden of cataracts in this population, the risks for operative complications related to PXF, and the fact that PXF may be used as a marker to aid in the detectection of glaucoma.

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.

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.

Phacoemulsification in Indian eyes with pseudoexfoliation syndrome

PURPOSE

To evaluate the intraoperative and postoperative behavior after phacoemulsification in Indian eyes with pseudoexfoliation syndrome.

SETTING

Iladevi Cataract & Intraocular Lens Research Centre, Ahmedabad, India.

METHOD

Ninety eyes were prospectively evaluated. Group 1 (cohort) comprised 45 consecutive eyes with pseudoexfoliation and coexisting cataract and Group 2 (control), 45 consecutive normal eyes with senile cataract only. Phacoemulsification was performed by a single surgeon using a step-by-step, chop in situ, and lateral separation technique. An AcrySof intraocular lens was implanted in the bag in all eyes. Intraoperative observations included pupil size after maximal mydriasis, phakodonesis, zonular dehiscence, grade of cataract, and capsule tear/rupture. Postoperatively, intraocular pressure (IOP), best corrected visual acuity, aqueous flare/cell response, and the presence of posterior synechias were evaluated at 1 day and 1 month. A chi-square test was used for statistical analyses.

RESULTS

The mean pupil size was significantly smaller in Group 1 (P =.0000). No eye in either group had phakodonesis. Sixty percent of eyes in Group 1 and 31% in Group 2 had a hard cataract (P =.008). Endocapsular phacoemulsification was performed in 82% of eyes in Group 1 and 84% of eyes in Group 2. Intraoperative complications such as zonular or capsular dehiscence were not seen in any eye. Postoperatively, IOP and aqueous cell response were comparable between groups (P =.11 and P = 0.81, respectively). A significantly higher flare response was observed in Group 1 (P =.000). The visual outcome at 1 month was similar between groups.

CONCLUSIONS

The intraoperative performance of Indian eyes with pseudoexfoliation was comparable to that in normal eyes. A good surgical outcome is ensured by using an appropriate surgical technique. Apart from a higher flare response, the postoperative outcomes in eyes with pseudoexfoliation were within normal limits, and the outcome at 1 month was satisfactory.

Exfoliation syndrome

Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix characterized by production and progressive accumulation of small, white deposits of a fibrillar extracellular material in many ocular tissues, most commonly seen on the pupillary border and anterior lens capsule. Characteristic signs of pigment liberation and deposition throughout the anterior segment aid in the diagnosis. Exfoliation syndrome predisposes to both open-angle and angle-closure glaucoma, and to capsular rupture, zonular dehiscence, and vitreous loss during cataract extraction. Exfoliation syndrome is associated with ocular and perhaps systemic ischemia. The exact chemical composition of exfoliation material remains unknown. Medical, laser, and surgical therapy are similar to treatment of primary open-angle glaucoma.

Inflammatory cell adhesion and surface defects on heparin-surface-modified poly(methyl methacrylate) intraocular lenses in diabetic patients

PURPOSE

To evaluate the incidence of surface scratches on heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) and the possible influence of these alterations on the biocompatibility of HSM PMMA.

SETTING

University Eye Clinic of Trieste, Trieste, Italy.

METHODS

Twenty-six diabetic patients had phacoemulsification and implantation of an HSM PMMA IOL (809C, Pharmacia & Upjohn). Patients with proliferative diabetic retinopathy or iridopathy were excluded from the study. On postoperative days 7, 30, 90, and 180, specular microscopy was performed to study and photograph the anterior IOL surface. The presence of scratches on the anterior IOL surface was assessed and the inflammatory cell reaction noted and graded using a semiquantitative scale. Finally, the location of the inflammatory cells in relation to the surface scratches was established.

RESULTS

Scratches and other surface defects were found in 88.4% of cases. All patients had small cells on the IOL surface 7 days after surgery. At 30 days, small cells were observed in 88.4% of cases. The inflammatory cells were mainly located inside the scratches rather than throughout the IOL surface.

CONCLUSIONS

This in vivo cytology study provides further evidence of the effectiveness of heparin surface modification in improving the biocompatibility of PMMA. In diabetic patients, inflammatory cells adhered to the exposed PMMA surface more than to the HSM surface, suggesting that the use of HSM PMMA in patients with conditions predisposing them to increased postoperative blood-aqueous barrier breakdown is beneficial.

Exfoliation syndrome

Exfoliation syndrome (XFS) is an age-related disease in which abnormal fibrillar extracellular material is produced and accumulates in many ocular tissues. Its ocular manifestations involve all of the structures of the anterior segment, as well as conjunctiva and orbital structures. Glaucoma occurs more commonly in eyes with XFS than in those without it; in fact, XFS has recently been recognized as the most common identifiable cause of glaucoma. Patients with XFS are also predisposed to develop angle-closure glaucoma, and glaucoma in XFS has a more serious clinical course and worse prognosis than primary open-angle glaucoma. There is increasing evidence for an etiological association of XFS with cataract formation, and possibly with retinal vein occlusion. XFS is now suspected to be a systemic disorder and has been associated preliminarily with transient ischemic attacks, stroke, systemic hypertension, and myocardial infarction. Further ramifications await discovery. Deposits of white material on the anterior lens surface are the most consistent and important diagnostic feature of XFS. The classic pattern consists of three distinct zones that become visible when the pupil is fully dilated. Whereas the classic picture of manifest XFS has been often described, the early stages of beginning exfoliation have not been well defined. Next to the lens, exfoliation material is most prominent at the pupillary border. Pigment loss from the iris sphincter region and its deposition on anterior chamber structures is a hallmark of XFS. Despite extensive research, the exact chemical composition of exfoliation material (XFM) remains unknown. An overproduction and abnormal metabolism of glycosaminoglycans have been suggested as one of the key changes in XFS. The protein components of XFM include both noncollagenous basement membrane components and epitopes of the elastic fiber system such as fibrillium. Regardless of etiology, typical exfoliation fibers have been demonstrated electron microscopically in close association with the pre-equatorial lens epithelium, the nonpigmented ciliary epithelium, the iris pigment epithelium, the corneal endothelium, the trabecular endothelium, and with almost all cell types of the iris stroma, such as fibrocytes, melanocytes, vascular endothelial cells, pericytes, and smooth muscle cells. The presence of XFS should alert the physician to the increased risks of intraocular surgery, most commonly zonular dehiscence, capsular rupture, and vitreous loss during cataract extraction. Heightened awareness of this condition and its associated clinical signs are important in the detection and management of glaucoma, and preoperative determination of those patients at increased risk for surgical complications.

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

OBJECTIVE

To compare postoperative inflammation occurring with heparin-surface-modified (HSM) versus non-HSM polymethyl methacrylate intraocular lenses (IOLs) after phacoemulsification.

DESIGN

Randomized, double-masked, multicenter, parallel trial.

PARTICIPANTS

A total of 367 patients, consisting of routine (n = 220), glaucoma (n = 58), and diabetes (n = 89) patients, from eight US medical centers.

METHODS

Patients were observed for 1 year after phacoemulsification and lens implantation (week 1, months 1, 3, 6, 12).

MAIN OUTCOME MEASURES

Primary measures of postoperative inflammation defined as the presence of giant cells on the lens surface via specular micrography and cellular deposits via slit-lamp examination.

RESULTS

The cross-sectional analyses showed that consistently fewer routine patients with HSM lens implants had giant cells on the IOL than those with non-HSM lens implants across all follow-up visits. The statistical significance (P < 0.05) was observed at all visits except month 12 for routine patients. The diabetes patients also demonstrated the same giant cell difference, and the statistical significance was observed at all visits including month 12. A similar trend was also observed in the glaucoma patients, with statistical significance only at the 3-month visit. For cell deposits, significant differences in favor of the HSM lens (P < 0.05) were observed at 3 months among routine and diabetes patients, and at 3 and 6 months among glaucoma patients. A longitudinal data analysis using the generalized estimating equation approach indicated statistically significant treatment effect of HSM lenses in reducing inflammation in all patients except for cellular deposits in diabetes patients. In all patient groups, sight-threatening complications were not reported either more frequently or with more severity than normally expected for patients who have undergone cataract extraction and IOL implantation.

CONCLUSIONS

The present study, the only one to have used phacoemulsification in virtually all patients (211/220 [96%] routine, 57/58 [98%] glaucoma, and 84/89 [94%] diabetes) is the largest to evaluate and compare concurrently routine, glaucoma, and diabetes patients. It is also the first US patient population study to document that heparin surface modification reduces postoperative inflammatory responses, as measured by specular micrography and slit-lamp examination, especially in the early postoperative period.

Phacoemulsification and modern cataract surgery

The techniques and results of cataract surgery have changed dramatically during the past three decades. In the USA, we have moved from intracapsular cataract extraction as the preferred technique to almost exclusively extracapsular techniques. Smaller incisions have become the standard, with phacoemulsification now being the method of choice for most surgeons. Along with these advances have come improved intraocular lens materials and designs, especially well suited for use with smaller incisions. Phacoemulsification as a method to remove the cataractous lens was first proposed more than 20 years ago. Advances in techniques and equipment have led to a dramatic increase in the popularity of phacoemulsification with increased safety and efficiency. Viscoelastic agents have been developed synchronously with modern phacoemulsification techniques, playing an integral role in the success of this new technology. Improved surgical techniques for removing the anterior lens capsule have decreased the incidence of both intraoperative and postoperative capsular complications. Nucleus removal, formerly performed primarily in the anterior chamber, is now performed in the posterior chamber, decreasing damage to the corneal endothelium. Improved wound construction allows many wounds to be left unsutured, and smaller wounds allow shorter recovery time and greater intraoperative control and safety. Intraocular lenses can have smaller optic sizes and still maintain accurate centration. Foldable intraocular lenses can take advantage of the smaller incision, even further shortening the time to visual recovery. Continual evolution of this technology promises to further improve patient outcomes after cataract surgery.

Phacoemulsification in eyes with pseudoexfoliation

PURPOSE

To compare intraoperative and postoperative complications in eyes with and without pseudoexfoliation having cataract surgery by phacoemulsification.

SETTING

Department of Ophthalmology, National Hospital, Oslo, Norway.

METHODS

Of 1152 consecutive phacoemulsification procedures, 164 cases with pseudoexfoliation (Group 1) and 916 cases without (Group 2) were followed for 4 months after cataract surgery in a prospective study. Of all cataract operations performed during that time, 96.2% were phacoemulsification procedures; 90.4 and 97.4% in eyes with and without pseudoexfoliation, respectively (P < .0005).

RESULTS

The frequency of capsular/zonular tear or vitreous loss was 9.6 and 3.7% in Groups 1 and 2, respectively (P = .0002). A visual acuity of 0.5 or better was achieved in 86.5% of eyes in Group 1 and 92.4% in Group 2 (P = .02). There were no statistically significant between-group differences in the frequency of a postoperative inflammatory response 1 day (6.7 versus 4.4%), 1 week (2.4 versus 1.6%), or 4 months (1.8 versus 0.9%) postoperatively.

CONCLUSION

Phacoemulsification was safe in most eyes with pseudoexfoliation even though significantly more complications occurred intraoperatively in these eyes. The low frequency of an inflammatory response indicates that the presence of pseudoexfoliation does not significantly increase the risk of inflammation.

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

PURPOSE

To evaluated 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.

Recurrent severe hypotony after cataract surgery in an eye with previous trabeculectomy

This report describes a patient who developed severe recurrent hypotony after uneventful phacoemulsification and intraocular lens (IOL) implantation 4 years after trabeculectomy. Hypotony was first noticed 1 month postoperatively and treated successfully with topical steroids. However, it reappeared 2 months later and slowly subsided only with steroid and cycloplegic treatment. There was no anterior chamber shallowing, leakage, or signs of inflammation. The cause of hypotony in this patient remains unknown. One possible explanation is subclinical postoperative inflammation as a foreign-body reaction to the IOL.

Prevalence and surgical complications of pseudoexfoliation syndrome in Portuguese patients with senile cataract

PURPOSE

To determine the prevalence and surgical complications of pseudoexfoliation syndrome (PES) in a Portuguese population of patients with senile cataract.

SETTING

Department of Ophthalmology, Coimbra University Hospitals, Coimbra, Portugal.

METHODS

In a prospective study, 183 consecutive patients with senile cataract referred to the Implant and Refractive Surgery Section of the Department of Ophthalmology were examined for PES. To determine the occurrence of intraoperative and postoperative complication of extracapsular extraction with posterior chamber intraocular lens implantation in patients with PES, two groups of similar age were compared: one with PES (n = 31) and a control group without PES (n = 31).

RESULTS

The prevalence of PES in the 183 Portuguese patients with senile cataract was 23.5%. There was statistically significant difference between the two groups in the presence of phacodonesis (P < .05), insufficient intraoperative mydriasis (P < .001), need to perform sphincterotomies to facilitate nucleus expression (P < .01), and formation of pupillary fibrin membranes in the postoperative period (P < .01). These complication were more frequent in the PES group. Zonular breaks also occurred more often in patients with PES, although this was not statistically significant.

CONCLUSIONS

Pseudoexfoliation syndrome was a common condition in patients with senile cataract having surgery in Portugal. Inadequate mydriasis was the major intraoperative difficulty; a pupil enlargement procedure should be performed in these cases. In the first days postoperatively, therapy with topical, subconjunctival, and systemic corticosteroids is recommended to reduce the inflammatory reaction in the anterior chamber.

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.