Clinical features of capsular glaucoma in comparison with primary open-angle glaucoma in Japan

Secondary glaucoma: Toward interventions based on molecular underpinnings

Glaucoma is a heterogeneous group of progressive diseases that leads to irreversible blindness. Secondary glaucoma refers to glaucoma caused by a known underlying condition. Pseudoexfoliation and pigment dispersion syndromes are common causes of secondary glaucoma. Their respective deposits may obstruct the trabecular meshwork, leading to aqueous humor outflow resistance, ocular hypertension, and optic neuropathy. There are no disease-specific interventions available for either. Pseudoexfoliation syndrome is characterized by fibrillar deposits (pseudoexfoliative material) on anterior segment structures. Over a decade of multiomics analyses taken together with the current knowledge on pseudoexfoliative glaucoma warrant a re-think of mechanistic possibilities. We propose that the presence of nucleation centers (e.g., vitamin D binding protein), crosslinking enzymes (e.g., transglutaminase 2), aberrant extracellular matrix, flawed endocytosis, and abnormal aqueous-blood barrier contribute to the formation of proteolytically resistant pseudoexfoliative material. Pigment dispersion syndrome is characterized by abnormal iridolenticular contact that disrupts iris pigment epithelium and liberates melanin granules. Iris melanogenesis is aberrant in this condition. Cytotoxic melanogenesis intermediates leak out of melanosomes and cause iris melanocyte and pigment epithelium cell death. Targeting melanogenesis can likely decrease the risk of pigmentary glaucoma. Skin and melanoma research provides insights into potential therapeutics. We propose that specific prostanoid agonists and fenofibrates may reduce melanogenesis by inhibiting cholesterol internalization and de novo synthesis. Additionally, melatonin is a potent melanogenesis suppressor, antioxidant, and hypotensive agent, rendering it a valuable agent for pigmentary glaucoma. In pseudoexfoliative glaucoma, where environmental insults drive pseudoexfoliative material formation, melatonin's antioxidant and hypotensive properties may offer adjunct therapeutic benefits. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.

Comparison between primary Ahmed valve implantation and primary trabeculectomy with mitomycin C in pseudophakic patients with exfoliative glaucoma

PURPOSE

To compare the efficacy and safety of primary Ahmed valve implantation (AVI) and primary trabeculectomy with mitomycin C (MMC) in patients with pseudophakic exfoliative glaucoma (XFG).

METHODS

All enrolled patients were divided into two groups: the TRAB group, comprising patients who underwent trabeculectomy with MMC, and the AVI group, comprising patients who underwent AVI. Intraocular pressure (IOP), mean deviation (MD), endothelial cell density of cornea (ECD), and the number of topical anti-glaucoma agents used during study period were retrospectively analyzed. Surgical success rates were compared between two groups using Kaplan-Meier survival analysis. Three levels of surgical success were defined as follows: (1) IOP ≤ 18 mmHg and an IOP reduction of 20% without medication; (2) IOP ≤ 15 mmHg and an IOP reduction of 25% without medication; and (3) IOP ≤ 18 mmHg and an IOP reduction of 20%, irrespective of medication.

RESULTS

The TRAB and AVI groups comprised 40 and 36 patients, respectively. At 36 months postoperatively, IOP was 15.7 ± 2.8 mmHg in the TRAB group and 16.9 ± 3.3 mmHg in the AVI group (p = 0.140). Surgical success rates in the TRAB group were 47.5, 37.5, and 77.5% and those in the AVI group were 41.6, 33.3, and 75.0% at 36 months for surgical criteria 1, 2, and 3, respectively. There were no statistically significant differences in the success rates between the two groups. However, regarding surgical criteria 2, the success rate of the AVI group at 1 year was significantly better than that of the TRAB group (p = 0.030).

CONCLUSIONS

Primary AVI was not inferior to primary trabeculectomy with MMC in medically uncontrolled patients with XFG.

Pseudoexfoliation Syndrome-Clinical Characteristics of Most Common Cause of Secondary Glaucoma

Pseudoexfoliation syndrome (XFS) is a condition in which excess material builds up not only in the structures of the anterior chamber but also throughout the body. The frequency of the syndrome varies significantly (0.3-18%) depending on the region and the method of examination. Environmental risk factors for XFS include a large number of sunny days, proximity to the equator, dietary factors such as higher consumption of coffee and tea, long-term alcohol consumption, exposure to UV, and outdoor work. The pathognomonic sign of XFS is the presence of white material on the lens capsule and other anterior chamber components. In addition, a characteristic Sampaolesi line can be observed during gonioscopy. Systemic alterations indicative of XFS have been observed in the extracellular matrix of the eyelid skin, the heart, lungs, liver, kidneys, gallbladder, meninges, and endothelium of the blood vessels. XFS is the most common cause of secondary open-angle glaucoma, which is called pseudoexfoliative glaucoma and is more severe than primary open-angle glaucoma. It is plausible that a combination of environmental factors and genetic alterations promotes the onset of pseudoexfoliation syndrome, which requires additional research.

Feasibility, efficacy and safety of early lens extraction in patients with pseudoexfoliation glaucoma: a feasibility and pilot study

Purpose

To evaluate the feasibility of a trial to compare the efficacy and safety of initial lens extraction surgery versus medical treatment for people with pseudoexfoliation glaucoma (PXFG) or ocular hypertension (OHT) and pseudoexfoliation syndrome.

Methods

This is a feasibility and pilot randomized controlled trial (RCT) in patients with newly diagnosed PXFG and mild cataract. The study was prospectively registered at ClinicalTrials.gov. An online survey was conducted among members of UK and Eire Glaucoma Society (UKEGS) and Spanish Glaucoma Society (SEG) with the aim of understanding current practices related to interventions for PXFG, the role of phacoemulsification and the willingness to participate in a definite trial. Participants were randomized into either early lens extraction surgery or medical treatment and deferred surgery Primary clinical outcome was intraocular pressure (IOP) at 12 months.

Results

The study was conducted between May 2019 and February 2021. Twelve patients were randomized, six in each group. Median IOP decreased significantly in both arms. Among the secondary outcomes of BVCA, reduction in the number of treatments and quality of life, statistically significant differences were found in favor of lens extraction. There were no differences in other secondary outcomes. No adverse effects occurred. Glaucoma experts would be willing to participate in a RCT.

Conclusions

A trial on early lens extraction surgery compared with medication in PXFG is feasible. Early lens extraction appears to be an effective treatment for PXFG, reducing the number of hypotensive drugs after surgery as well as improving patients’ quality of life.

Association of Epiretinal Membrane With Pseudoexfoliation Glaucoma and Long-term Factors Affecting Visual Function

PRCIS

Epiretinal membrane (ERM) tended to deteriorate more in pseudoexfoliation eyes with than without glaucoma. Incremental change in central macular thickness (CMT) induced by ERM deterioration affected longitudinal visual function in pseudoexfoliation glaucoma (PXG) eyes.

PURPOSE

The aim was to investigate longitudinal changes in the ERM and their association with glaucoma in patients with pseudoexfoliation syndrome (PXS) and to identify factors associated with the changes in ERM and visual field (VF).

PARTICIPANTS

One hundred two eyes with PXG and 32 eyes with nonglaucomatous pseudoexfoliation (ngPX) (mean 8.1±2.6 years of follow-up).

METHODS

Two observers independently assessed the presence and staging of ERM (stages 1, 2, and ≥3) on serial macular images of spectral-domain optical coherence tomography. Clinical characteristics were compared in eyes with ERM (+) and (-) in both groups. The relationship between putative factors and changes in ERM was determined using logistic regression analysis. Prognostic factors of VF worsening were assessed by Cox proportional hazard analysis.

RESULTS

Of the 102 eyes with PXG, 22 (21.6%) had an ERM at baseline; of the latter, 6 eyes deteriorated (all from stage 1 to 2) and 3 eyes with PXG developed new ERM during follow-up. Of the 32 ngPX eyes, 8 (25%) had an ERM at baseline, with none changing over time. The presence of glaucoma was marginally associated with ERM deterioration (odds ratio: 1.061, P =0.064). Incremental change in CMT was the only factor associated with VF progression (hazard ratio: 1.040, P =0.029) in PXG eyes.

CONCLUSIONS

ERM tended to deteriorate more in PXS eyes with than without glaucoma. Incremental change in CMT induced by ERM deterioration affected longitudinal visual function in PXG eyes.

Evaluation of Anterior Segment Parameters in Pseudoexfoliation Disease Using Anterior Segment Optical Coherence Tomography

PURPOSE

To compare anterior segment and angle parameters between pseudoexfoliation syndrome (PEX) and PEX glaucoma (PEXG) and normal control subjects using anterior segment optical coherence tomography (AS-OCT) imaging.

DESIGN

Cross-sectional study.

METHODS

One hundred and two subjects with PEXG, PEX, and normal eyes as the control group were recruited from an academic referral institution. All subjects underwent a complete ophthalmologic examination, axial length measurement, and AS-OCT imaging. Anterior segment and angle parameters were evaluated.

RESULTS

After excluding 4 eyes because of poor imaging of the scleral spur, data from 34 eyes with PEXG, 33 eyes with PEX, and 31 eyes of normal control subjects were analyzed. Anterior chamber depth was significantly shallower in eyes with PEXG compared with eyes of control subjects (P < .001). The differences in anterior chamber angle parameters (AOD500, AOD750, TISA500,and TISA750) were significant among study groups, with lower values in the PEXG group compared with the PEX and control subject groups. Lens vault (mean [mm]±SD) was higher in the PEXG (0.46 ±0.21) and PEX (0.427 +0.28) groups compared with the control group (0.305+ 0.20).

CONCLUSIONS

PEXG eyes have the narrowest anterior chamber angle parameters. There is a progressive decrease in angle parameters from control subjects to the PEX group to the PEXG group. Narrow anterior chamber angle and anterior chamber depth may have a role in the progression of PEX to PEXG. Detection of narrow angle in these patients may help clinicians manage the disease more properly.

Comparison of the Prevalence and Clinical Characteristics of Epiretinal Membrane in Pseudoexfoliation and Primary Open-angle Glaucoma

PURPOSE

The purpose of this study was to investigate and compare the prevalence and clinical characteristics of epiretinal membrane (ERM) in patients with pseudoexfoliation glaucoma (PXG) and primary open-angle glaucoma (POAG).

METHODS

In this retrospective observational study, 211 PXG eyes, 210 age-matched normal eyes, and 220 POAG eyes were included. The presence and staging of ERM (stage 1, 2, and 3 or greater) were independently assessed by 2 observers. Univariate and multivariate linear regression analyses were performed to assess the factors associated with visual field (VF) mean deviation (MD) in PXG eyes.

RESULTS

Among 211 PXG eyes, 40 (19.0%) had an ERM, while 4.1% of POAG and 2.4% of normal eyes had an ERM (P<0.001). Retinal nerve fiber layer thickness (69.4 vs. 70.4 μm, P=0.477) and VF MD (-7.7 vs. -10.4 dB, P=0.098) were not different between POAG and PXG eyes but macular thickness was greater (259.5 vs. 271.5 μm, P=0.006) in PXG eyes than in POAG. Both lower retinal nerve fiber layer thickness (β=0.337, P<0.001) and the presence of an ERM (β=-4.246, P=0.002) were independently associated with worse VF MD in PXG eyes.

CONCLUSIONS

The prevalence of ERM was significantly greater in PXG eyes than in age-matched normal or POAG eyes. The presence of ERM affected VF in PXG eyes.

One-year outcomes of microshunt implantation in pseudoexfoliation glaucoma

PURPOSE

To compare the safety and efficacy of microshunt implantation augmented with Mitomycin C in patients with pseudoexfoliation glaucoma (PEXG) and primary open-angle glaucoma (POAG).

METHODS

In this retrospective, single centre, interventional study, 46 eyes of 41 patients with PEXG (20 eyes) and POAG (26 eyes) underwent microshunt implantation. Definition of failure was an intraocular pressure (IOP) lower than 5 or higher than 17mmHg on two consecutive visits, an IOP reduction lower than 20% on two consecutive visits, the need of surgical revisions or reoperations or loss of light perception. Outcome was rated as complete success if achieved without medication, otherwise as qualified success. Furthermore, postoperative complications and interventions were compared between the two groups.

RESULTS

Patient demographics were similar, except for older age in the PEXG group (70.9±8.6 versus 77.6±8; p = 0.02). Mean IOP dropped from 21.5±5.8mmHg (PEXG) and 18.2±4.5mmHg (POAG) at baseline to 12.8±3.0mmHg (p<0.0001) and 12.9±4.2mmHg (p<0.0001), respectively, at one year. Mean number of medications were reduced from 2.8±1.3 to 0.3±0.8 for PEXG patients (p<0.0001) and from 2.7±1.3 to 0.3±0.8 for POAG patients (p<0.0001). At one year of follow-up 75.0% of PEXG patients achieved complete success and 80.0% qualified success. In the POAG group rates were 73.1% and 76.9%, respectively. Postoperative complications were comparable between both groups, except for higher rates of hypotony (p = 0.04) and choroidal detachment (p = 0.03) in the PEXG group.

CONCLUSION

Microshunt implantation demonstrated similar efficacy results in PEXG and POAG eyes at a follow-up of 12 months. Higher rates of transient hypotony and choroidal detachment were observed in PEXG eyes.

Efficacy and Safety of Primary Glaucoma Device Implantation Surgery in Exfoliative Glaucoma: A Retrospective Consecutive Case Series

Purpose

To evaluate the efficacy and safety of primary glaucoma drainage implant (GDI) surgery for exfoliation glaucoma (XFG).

Methods

This study was a retrospective, consecutive case series study including 36 eyes of 36 patients with XFG who underwent primary GDI surgery. Intraocular pressure (IOP), the mean deviation (MD) from the visual field exam, corneal endothelial cell density (ECD), and the number of topical antiglaucoma agents used during the preoperative and postoperative periods were retrospectively analyzed. Surgical success was defined by the following criteria: (1) IOP ≤ 18 mmHg and an IOP reduction of 20% with 1 or no medication; (2) IOP ≤ 15 mmHg and an IOP reduction of 25% with 1 or no medication; and (3) IOP ≤ 12 mmHg and an IOP reduction of 30% with 1 or no medication. The probability of success of GDI surgery was determined via Kaplan–Meier survival analysis.

Results

The preoperative IOP was 25.9 ± 4.7 mmHg, and the postoperative IOP at 24 months was decreased to 14.2 ± 3.6 mmHg (p value < 0.001). The postoperative MD and ECD were similar to baseline (MD p value = 0.155; ECD p value = 0.055). However, a significant reduction in the number of antiglaucoma agents was observed (p value < 0.001). The surgical success rates were 77.8%, 63.9%, and 55.6% at 24 months for criteria 1, 2, and 3, respectively. Early hypotony (4 patients, 11.1%) and persistent corneal edema (5 patients, 13.9%) were the most common early and late postoperative complications, respectively.

Conclusions

In XFG, primary GDI surgery reduced IOP by 45.2% and had a 77.8% success rate according to criteria 1 at 24 months postoperatively. However, considering that ECD reduction continues to decline over time, primary GDI surgery should be carefully considered in XFG.

Selective laser trabeculoplasty in exfoliative glaucoma eyes with prior argon laser trabeculoplasty

PURPOSE

To explore the efficacy of selective laser trabeculoplasty (SLT) within eyes with exfoliative glaucoma and history of prior argon laser trabeculoplasty (ALT).

METHODS

A single-centre trial consisting of 47 patients (47 eyes) with uncontrolled exfoliative glaucoma. The main outcome measure was intraocular pressure (IOP) reduction 3 and 9 months after SLT. Treatment success was defined as reduction from the preoperative IOP by 20% and 2 mmHg (<12 mmHg), 3 mmHg (12-16 mmHg) or 4 mmHg (>16 mmHg) depending on the baseline IOP.

RESULTS

Patient age was 79.3 ± 7.6 years (mean ± SD) and gender distribution 15 males and 32 females. The mean pre-SLT IOP was 15.6 ± 5.1 (range 9-28) mmHg, and mean number of glaucoma drugs 2.0 ± 1.2. The mean interval between prior ALT and SLT was 44.0 ± 36.9 (range 11-137) months. After SLT, the mean IOP change was -2.7 ± 4.2 mmHg (-14.8 ± 23.5%) at 3 months, and -2.8 ± 3.5 mmHg (-16.3 ± 19.4%) at 9 months. Pre-SLT IOP correlated with the IOP reduction at 3 months (r = 0.530, p < 0.001) and at 9 months (r = 0.432, p = 0.007). The overall success rate was 50% at 3 months, and 42% at 9 months. At both 3 and at 9 months, the cut-off level for treatment success was achieved when preoperative IOP was 18 mmHg and above. IOP lowering effect of SLT did not correlate with the number of glaucoma drugs, age, gender or use of prostaglandin inhibitors. Neither postoperative iritis nor other adverse effects were documented during the follow-up.

CONCLUSIONS

Selective laser trabeculoplasty is a safe and noteworthy treatment option to reduce IOP in exfoliative glaucoma eyes, especially with pre-SLT IOP over 18 mmHg.

Recent Advances in the Surgical Management of Glaucoma in Exfoliation Syndrome

Surgical and laser procedures traditionally used in the management of exfoliation glaucoma (XFG) include laser trabeculoplasty, trabeculectomy, and glaucoma drainage implant surgery. Having demonstrated similar safety and efficacy in XFG compared with primary open-angle glaucoma, trabeculectomy remains the most commonly performed surgery in XFG. Recent trends in practice patterns in developed nations demonstrate a shift towards glaucoma drainage implant surgery, which is currently the procedure of choice in XFG for many, particularly in developed nations. In addition, cataract surgery alone may significantly decrease intraocular pressure in patients with XFG, may prevent glaucoma development in patients with exfoliation syndrome, and is recommended to be performed early in the course of the disease. With the relatively recent introduction of nonpenetrating glaucoma surgery and the ongoing evolution of minimally invasive glaucoma surgery, several other surgical procedures have now become part of the glaucoma surgeon's armamentarium when treating XFG, including the Ex-PRESS shunt, deep sclerectomy, viscocanalostomy, Trabectome, as well as angle procedures. These techniques have demonstrated promising results in various types of glaucoma. More research is, however, needed to establish the safety and efficacy of these procedures in XFG.

Presentation and Long-Term follow-up of Exfoliation Glaucoma in Greece, Spain, Russia, and Hungary

Purpose

To evaluate clinical presentation and long-term follow-up of exfoliation glaucoma in separate European population groups.

Methods

A four-center, retrospective, case series analysis in which 200 charts of patients with exfoliation glaucoma or patients with elevated intraocular pressure (IOP) associated with exfoliation syndrome in at least one eye with at least 5 years of follow-up were consecutively reviewed.

Results

This study found an average follow-up time of 6.0±2.1 years. Patients in Hungary and Spain statistically presented at an older age (79 years) than Greek patients (67 years). Patients with exfoliation glaucoma in Greece and Hungary had more glaucomatous damage, had more severe glaucoma, had a higher untreated IOP (31.8 to 32.1 mmHg), and were more difficult to control, showing a greater number of changes in medicines during the follow-up period, a greater number of medicines at the end of the follow-up period, and more progression. On long-term follow-up, Greek, Russian, and Hungarian patients also had the highest mean IOP (18.8 to 20.8 mmHg) and the greatest incidence of progression (approximately 50%). Spanish patients demonstrated the lowest mean IOP (17.6±3.6 mmHg) and the lowest rate of progression (28%) during the follow-up period and the fewest number of medications per patient (0.7) to control the IOP at the end of the follow-up period.

Conclusions

The severity of exfoliation glaucoma presentation and its course may differ within distinct geographic populations in Europe.

Structure-Function Correlation Using Confocal Laser Ophthalmoscope in Primary Open-Angle Glaucoma and Pseudoexfoliative Glaucoma

PURPOSE

To compare Heidelberg Retina Tomograph (HRT) optic disc parameters and structure-function correlation between primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG).

DESIGN

Prospective, observation case series.

PATIENTS AND METHODS

A total of 54 POAG and 33 PEXG cases, consecutively recruited from a University Glaucoma Service, underwent a comprehensive ophthalmic examination, including HRT optic disc imaging. Glaucoma definition required the presence of both structural and functional damage. One eye per subject was included in the analysis. T test, Mann-Whitney U test, and analysis of covariance were used to compare HRT parameters between POAG and PEXG, adjusting for age, mean deviation (MD) in the visual field, intraocular pressure, and disc area. The correlation between HRT and MD was assessed in each group.

RESULTS

Cup area (P=0.048), height variation contour (P=0.016), and cup/disc area ratio (P=0.023) were higher in POAG, whereas the mean retinal nerve fiber layer thickness (P=0.048), retinal nerve fiber layer cross-section area (P=0.044), and rim area (P=0.048) were lower in POAG, compared with PEXG. The correlation of HRT parameters with MD was significant only in the POAG group.

CONCLUSIONS

At a similar level of functional damage, POAG subjects presented with more pronounced structural damage than PEXG subjects. The correlation between HRT and visual field parameters was more evident in POAG, compared with PEXG.

Does cataract surgery reduce the long-term risk of glaucoma in eyes with pseudoexfoliation syndrome?

PURPOSE

To compare glaucoma development and intraocular pressure (IOP) in the longer term following phacoemulsification cataract surgery in eyes with and without pseudoexfoliation syndrome (PEX).

METHODS

Fifty-one patients with PEX were compared with 102 age- and gender-matched controls without PEX. Patients were re-examined a mean of 76 (SD 5.4) months after cataract surgery, recording IOP, glaucoma diagnosis, glaucoma treatment and LogMAR. Data from the preoperative visit (baseline) and IOP on the first postoperative day were obtained from medical records. A glaucoma parameter was predefined as patients developing glaucoma or needing increased glaucoma treatment during the postoperative time period.

RESULTS

One new glaucoma case in each group was diagnosed postoperatively, yielding glaucoma incidences of 0.47 cases per 100 person-years [95% confidence interval (CI) 0.006-2.61] and 0.17 cases per 100 person-years (CI 0.002-0.95) in the PEX and control groups respectively (p = 0.53). IOP declined by 2.6 (SD 4.0) mmHg in the PEX group (p < 0.001) and 1.9 (SD 3.5) mmHg in the control group (p < 0.001) from baseline to the re-examination, with a non-significant group difference (p = 0.310). IOP spike (≥6 mmHg increase) was significantly associated with the glaucoma parameter, both within the PEX (p = 0.034) and the control group (p = 0.044).

CONCLUSION

The number of newly diagnosed glaucoma cases was lower than expected 6-7 years following cataract extraction, especially in the PEX group, which indicates that PEX eyes benefit particularly from cataract surgery in terms of IOP and glaucoma development.

Pseudoexfoliation syndrome at a Singapore eye clinic

Background

The purpose of this study was to investigate the demographics of pseudoexfoliation syndrome (PXF) and pseudoexfoliative glaucoma (PXG) in a Singapore hospital eye outpatient clinic.

Methods

A retrospective study of 93 consecutive patients (146 eyes) with PXF was undertaken by a single ophthalmologist over a period of 37 months (July 1, 2006, to July 31, 2009).

Results

Ninety-three (2.8%) of 3,297 patients seen during the study period were diagnosed with PXF. Forty-three (46.2%) of the 93 PXF patients were male. Indians were 5.04 times more likely to develop PXF than Chinese (P<0.001, 95% confidence interval 3.05–8.33), while Malays were 2.22 times more likely to develop PXF as compared with Chinese (P=0.029, 95% CI 1.08–4.55). Twenty-two (23.7%) of the 93 PXF patients had PXG at the time of diagnosis. There was no statistically significant difference in mean age between PXF and PXG patients. There was a larger proportion of males with PXG than females (P<0.001).

Conclusion

PXF is not infrequent in elderly Singapore eye clinic patients, and is more likely to occur in Indians than in Chinese. In the Singapore eye clinic setting, males may be more likely to develop PXG, although larger studies will be required to confirm this.

A Hybrid Swarm Algorithm for optimizing glaucoma diagnosis

Glaucoma is among the most common causes of permanent blindness in human. Because the initial symptoms are not evident, mass screening would assist early diagnosis in the vast population. Such mass screening requires an automated diagnosis technique. Our proposed automation consists of pre-processing, optimal wavelet transformation, feature extraction, and classification modules. The hyper analytic wavelet transformation (HWT) based statistical features are extracted from fundus images. Because HWT preserves phase information, it is appropriate for feature extraction. The features are then classified by a Support Vector Machine (SVM) with a radial basis function (RBF) kernel. The filter coefficients of the wavelet transformation process and the SVM-RB width parameter are simultaneously tailored to best-fit the diagnosis by the hybrid Particle Swarm algorithm. To overcome premature convergence, a Group Search Optimizer (GSO) random searching (ranging) and area scanning behavior (around the optima) are embedded within the Particle Swarm Optimization (PSO) framework. We also embed a novel potential-area scanning as a preventive mechanism against premature convergence, rather than diagnosis and cure. This embedding does not compromise the generality and utility of PSO. In two 10-fold cross-validated test runs, the diagnostic accuracy of the proposed hybrid PSO exceeded that of conventional PSO. Furthermore, the hybrid PSO maintained the ability to explore even at later iterations, ensuring maturity in fitness.

Comparison of primary open-angle glaucoma and exfoliation glaucoma at diagnosis

PURPOSE

To compare ocular findings in eyes with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EG) at the time of diagnosis when identical diagnostic criteria for glaucoma were applied.

METHODS

We conducted a study on records of 519 consecutive, unselected patients with chronic glaucoma filing for cost-free medication from the Finnish National Social Insurance Institute (FSII). Fourteen cases were excluded for having other types of glaucoma. The documents were provided by eye hospitals or by licensed ophthalmologists. The criteria for glaucoma were set by the Parliament of Finland and applied by FSII. A total of 329 patients had POAG and 176 had EG. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), cup-to-disc ratio of the optic nerve head (C/D), and glaucomatous changes of the visual fields (VF).

RESULTS

As regards sex, the 2 groups were comparable: 66% female with POAG and 68% with EG. The EG patients were older (mean ± SD 74 ± 8.6 years) vs POAG (68 ± 11.4 years). The EG eyes had slightly lower BCVA. The POAG eyes had mean intraocular pressure (IOP) 24 ± 5.4 mm Hg. A total of 12% in this group had highest IOP of less than 18 mm Hg (low-tension glaucoma [LTG]) but there were none of EG. All EG eyes had a mean IOP 28.3 ± 9.3 mm Hg. Among EG patients, 26% had unilateral disease, with a mean IOP of 33.7 ± 8.7 mm Hg, while the opposite eyes had a mean of 19 ± 3 mm Hg. There was not much difference in the C/D ratios of POAG and EG eyes and the VF profiles were similar.

CONCLUSIONS

At diagnosis, patients with EG were older than those with POAG and had higher mean IOP values. Among patients with POAG, there were 12% with LTG, but none among EG. A total of 26% among EG had unilateral disease with marked IOP asymmetry. The C/D and VF profiles were similar because the patients had been seen early in the disease course. Early recognition and lifelong most effective therapy of EG are strongly advocated.

Increased likelihood of glaucoma at the same screening intraocular pressure in subjects with pseudoexfoliation: the Thessaloniki Eye Study

PURPOSE

To compare the clinical characteristics of primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG) identified in the Thessaloniki Eye Study and to evaluate the proportion of subjects with and without pseudoexfoliation (PEX) who have glaucoma by screening intraocular pressure (IOP).

DESIGN

Cross-sectional, population-based study.

METHODS

Randomly selected subjects > or =60 years (n = 2,554) participated in the Thessaloniki Eye Study. Subjects were classified as having POAG or PEXG according to specific criteria. POAG and PEXG cases were compared for various clinical characteristics. The proportion with glaucoma among subjects with PEX and the proportion with glaucoma among subjects without PEX were estimated by IOP levels.

RESULTS

Among the clinic-visit participants (n = 2,261), 94 subjects (4.2%) had POAG and 41 (1.8%) had PEXG. The prevalence of glaucoma among subjects with PEX was 15.2% and the prevalence of glaucoma among subjects without PEX was 4.7%. In subjects without treatment, the mean IOPs were 19.8 mm Hg and 24.3 mm Hg for POAG and PEXG, respectively. For IOP level >20 mm Hg, the proportion with glaucoma among subjects with PEX was higher than that for glaucoma among subjects without PEX (37% vs 15%; P = .004), while no statistically significant difference was found for IOP level < or =20 mm Hg (2.1% vs 2.1%; P = .999), Fisher exact test.

CONCLUSIONS

In the Thessaloniki Eye Study, for screening IOP </=20 mm Hg the proportion with glaucoma was similar in subjects with and without PEX. For IOP level >20 mm Hg, the proportion with glaucoma increased highly in subjects both with and without PEX, while it was much higher among those with PEX at the same screening IOP.

Cataract and glaucoma surgery in pseudoexfoliation syndrome: a review

Pseudoexfoliation syndrome is a risk factor in cataract surgery because of the increased weakness of zonular apparatus and reduced pupillary dilatation. The surgical outcome of using phacoemulsification in the central zone, inducing minimal stress on the zonules, inserting a capsular tension ring in selected cases, and stretching the pupil mechanically in eyes with miotic pupils, may turn out to be uneventful in most cases. Postoperative fibrosis with subsequent shrinkage of the capsule is increased in these eyes, and these centripetal forces will further loosen the zonular fibres. Late in-the-bag intraocular lens dislocation is therefore anticipated to become a growing problem in the future. Despite the dysfunctioning of the blood-aqueous barrier in eyes with pseudoexfoliation syndrome, the frequency of postoperative inflammatory reaction is low due to the improvements made in surgical technique and equipment in recent years. Glaucoma frequently occurs in eyes with pseudoexfoliation syndrome. Compared with primary open-angle glaucoma, optic damage is more pronounced in these eyes at the time of diagnosis and response to medical therapy is poorer. Although responses to argon laser therapy and filtering surgery are roughly similar between the two types of glaucoma, there are indications that primary laser trabeculoplasty has a higher success rate in pseudoexfoliation glaucoma than in primary open-angle glaucoma.

The Risk of Glaucoma in Pseudoexfoliation Syndrome

PURPOSE

To determine the conversion rate of pseudoexfoliation syndrome (PEX) to pseudoexfoliative glaucoma or treated ocular hypertension.

METHODS

Retrospective community-based study of newly diagnosed cases of PEX syndrome in all residents of Olmsted County, Minnesota between 1976 and 1991. The end point was considered the initiation of therapy, which included patients with glaucoma (optic disc damage or visual field defects), or with elevated intraocular pressure (IOP) >21 mm Hg in the presence of risk factors; the subsequent development of damage in the latter group was also determined.

RESULTS

Two hundred fifty-five patients (318 eyes) had newly diagnosed PEX over the 15-year interval. Mean age was 73+/-10 years; 78% (199/255) were female. Of all PEX patients, 16% were placed on therapy at the time of initial diagnosis of PEX. In the remaining PEX patients, the probability of being placed on therapy was 44% at 15 years. Bilateral PEX was present in 25% at initial diagnosis and developed in another 29% by 15 years. Of those not placed on therapy, 16% (23/142) had IOP increase 5+ mm Hg during follow-up, with 11% (16/142) reaching 22 mm Hg or more. The strongest risk factors for converting to therapy were IOP at initial diagnosis of PEX and bilateral involvement.

CONCLUSIONS

In a geographically defined population of PEX patients, 16% required treatment upon presentation. Of the remaining PEX patients, 44% received therapy over the next 15 years.

Matrix metalloproteinases and their inhibitors in the chamber angle of normal eyes and patients with primary open-angle glaucoma and exfoliation glaucoma

BACKGROUND

In glaucoma, extensive pathological changes occur in the trabecular meshwork (TM) and juxtacanalicular tissue of the chamber angle. Aqueous humor drainage is disturbed due to the accumulation of extracellular matrix (ECM) material in the outflow system. Matrix metalloproteinases (MMPs) remodel ECM material and, thus, they may have a role in regulating outflow facility and intraocular pressure (IOP). This study examined the expression of MMPs and tissue inhibitors of MMPs (TIMPs) in the chamber angle of normal eyes and in primary open-angle glaucoma (POAG) and in exfoliation glaucoma (ExG).

METHODS

TM tissues were isolated from healthy donor eyes for corneal transplantation. Specimens of the inner wall of Schlemm's canal and the juxtacanalicular tissue were collected from patients with POAG or ExG during deep sclerectomy operation. Monoclonal antibodies against MMPs (MMP-1, -2, -3, and -9) and antibodies against TIMPs (TIMP-1, -2, and -3) were used for immunohistochemical staining.

RESULTS

Immunoreactivity for MMP-2, TIMP-2, or TIMP-3 was observed in human normal TM and in the inner wall of Schlemm's canal. In general, immunoreactions for all of the tested MMPs were more intense in POAG samples than in ExG samples or in the control group. The only exception was the MMP-2 level, which was the highest in the control group. The staining intensity of MMP-1 or MMP-3 was significantly higher in POAG when compared to ExG. TIMP-1 was significantly increased in POAG compared with ExG and there were no marked differences in the levels of TIMP-2 or TIMP-3 between POAG and ExG. The ratios of MMP-1/TIMP-1 and MMP(1+2+3+9) and TIMP(1+2+3) were significantly higher in samples from POAG compared to those of ExG.

CONCLUSIONS

Our results reveal an expression imbalance between MMPs and their endogenous tissue inhibitors in tissue samples from patients with POAG and ExG. Differences in immunohistochemical reactions reflect discrete local pathogenic mechanisms involved in POAG and ExG. With respect to the proposed role of MMPs in the remodeling of ECM material, this may point to a weaker reactivity to the accumulation of ECM material in TM in ExG than POAG eyes.

Deep sclerectomy for the treatment of exfoliation and primary open-angle glaucoma

PURPOSE

To retrospectively compare the efficacy of deep sclerectomy in the treatment of primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG).

METHODS

Deep sclerectomy with either collagen or hyaluronate implants was performed in 31 eyes (45%) with POAG and 38 eyes (55%) with ExG. Pre- and postoperative intraocular pressure (IOP) was recorded, as was the number of glaucoma medications used pre- and postoperatively in each group. The follow-up data referred to a mean period of 18 months (range: 2 weeks to 36 months).

RESULTS

At 18 months, complete success had been achieved in 56.3% of POAG eyes and 44.9% of ExG eyes. Qualified success had been achieved in 83.1% and 71.6% of POAG and ExG eyes, respectively. The mean IOP was 18.6 mmHg in POAG eyes and 16.3 mmHg in ExG eyes. YAG-descemetotomies were performed in nine eyes in each group. There were no statistically significant differences between the groups in IOP (except at 1 week postoperatively in favour of POAG; p = 0.05), success rates, need for postoperative glaucoma medication or number of complications. Reoperations were required in three (10%) POAG eyes and seven (18%) ExG eyes.

CONCLUSIONS

Deep sclerectomy is equally effective in controlling IOP in both POAG and ExG and has low rates of serious complications, even when the surgeon is inexperienced in the technique. Both survival rates and IOP control were similar between the groups, and there were no serious intra- or postoperative complications.

Intraocular pressure following phacoemulsification in patients with and without exfoliation syndrome: a 2 year prospective study

AIM

To determine the long term intraocular pressure (IOP) response to phacoemulsification in patients with and without exfoliation syndrome (XFS).

METHODS

Prospective, multicentre, cohort study with the following inclusion criteria: age over 50 years, open iridocorneal angle, and cataract. Two groups were enrolled: those with XFS and those without. The main outcome was mean IOP reduction 2 years after phacoemulsification cataract extraction (PCE). Univariate and multivariate analyses were performed.

RESULTS

183 patients were enrolled, 71 with and 112 without XFS. There were 29 patients with glaucoma in both groups. Mean baseline IOP was higher in XFS compared to control eyes (17.60 (SD 3.23) mm Hg v 16.08 (3.18) mm Hg, p = 0.002). Overall IOP reduction was significantly greater in the XFS group at the 2 year time point (-1.85 mm Hg v -0.62 mm Hg in the controls (p = 0.0037)). Multivariate analysis demonstrated that the IOP lowering effect in the XFS group may be related to irrigation volume at the time of surgery. In the subgroup analyses IOP lowering was significantly greater in the XFS and XFG patients than in controls without glaucoma, and POAG controls, respectively. The percentage of patients with a postoperative IOP spike was similar and relatively high in both XFS and control groups (34% v 25%; p = 0.54).

CONCLUSION

IOP decreases more in patients with XFS following PCE compared to control eyes without XFS. This effect is more pronounced in glaucoma patients and persists for at least 2 years.

Patienten mit sekundärem Offenwinkelglaukom bei Pseudoexfoliations- (PEX-)Syndrom in einer Bevölkerung mit hoher PEX-Prävalenz

BACKGROUND

The second most frequent treatable cause of noninfectious blindness in Oman is high-pressure glaucoma. Therefore, in 2002 a study was performed at our department of ophthalmology to evaluate pseudoexfoliation (PEX) in glaucoma patients.

METHODS

In a prospective comparative cohort study, of 204 glaucoma eyes, 135 open-angle glaucomas were evaluated by biomicroscopy, papillometry, and electron microscopy and followed up after 6 months.

RESULTS

The incidence of PEX glaucomas relative to all glaucomas was 50.9% and to open-angle glaucomas 77%. The IOP level in PEX was higher than in POAG; the CDR, neuroretinal rim zone, and the visual field loss were not significantly different. In 38 of 104 operated PEX glaucoma eyes, the postoperative visual acuity deteriorated although the IOP was controlled.

CONCLUSIONS

PEX high-pressure glaucomas account for half of all glaucomas in the eastern region of the Arabian peninsula. Surgical outcomes feature a high percentage of postoperative reduction of vision in the late PEX stage.

Exfoliation syndrome angle characteristics: a lack of correlation with amount of disc damage

BACKGROUND/AIMS

The exact pathogenesis of glaucoma in exfoliation syndrome is unclear. There has been some suggestion that narrow angles are more common in exfoliation syndrome and that this may be a component in the disease. The degree of pigmentation has also been shown to influence the intraocular pressure. The aim was to determine whether gonioscopic features of the anterior chamber angle in patients with exfoliation syndrome correlate with severity of the glaucoma.

METHODS

A prospective study of consecutive patients with exfoliation syndrome was carried out. 78 patients with exfoliation syndrome were examined by one clinician (GLS), and underwent gonioscopy and dilated funduscopy.

RESULTS

Anterior chamber angle, level of iris insertion, degree of pigmentation and the presence or absence of a Sampaolesi line were not correlated with the degree of disc damage.

CONCLUSIONS

There was no apparent association between angle characteristics and the severity of glaucoma in patients with exfoliation syndrome.

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.

A comparison of glaucoma patients identified through mass screening and in routine clinical practice

PURPOSE

To study differences between glaucoma patients identified through a population screening and glaucoma patients diagnosed in routine clinical practice (self-selected patients).

METHODS

A total of 402 individuals with newly detected open-angle glaucoma were identified through a large population screening programme that ran from October 1992 to January 1997. The screening programme was attended by a total of 32918 citizens of Malmö, Sweden, aged between 57 and 79 years. Citizens who had visited the Eye Department of Malmö University Hospital in the year before the screening of their birth cohort were not invited to participate (n = 4117). Among the latter, we identified 354 patients with open-angle glaucoma through a retrospective examination of patient records.

RESULTS

At detection, 52.9% of the glaucoma patients identified through screening had normal tension glaucoma (NTG), defined as intraocular pressure (IOP) < 21 mmHg in both eyes, compared to 13.5% of the self-selected patients (p < 0.0001). Mean IOP at the time of diagnosis was 22.9 mmHg in the screened group and 32.5 mmHg in the self-selected group. Pseudoexfoliation was present in 16.4% of the screened group and 44.0% of the self-selected group (p < 0.01). Bilateral disease was present in 40.1% of the screened group and 34.6% of the self-selected group (p = 0.1160). Median MD (mean deviation from the age-corrected normal visual field) in the worse eye was -8.0 dB in the screened group and -16.2 dB in the self-selected group (p < 0.0001). Visual acuity was lower in the self-selected group, which was also on average slightly more myopic. Of the patients detected through screening, 62% had seen an ophthalmologist previously, 17% within the preceding 2-year period.

CONCLUSIONS

Normal tension glaucoma was four times as common in patients identified through population screening as in self-selected patients, suggesting that patients with NTG are easily overlooked in clinical practice. Even though the patients detected through population screening had lower mean IOP, lower prevalence of pseudoexfoliation, better visual fields and a lower incidence of bilateral disease than self-selected patients, many still had considerable damage. Special efforts, such as glaucoma screening, are needed if manifest glaucoma, and especially NTG, is to be detected at an earlier stage than it currently is.

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.

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.

The comparative analysis of optic disc damage in exfoliative glaucoma

To compare the initial and follow-up discernible glaucomatous neuroretinal rim (NRR) and parapapillary chorioretinal changes in patients with primary open-angle glaucoma (POAG) and exfoliative glaucoma (EG), we analyzed 40 optic discs from 40 patients with POAG, 40 optic discs from 40 patients with EG and 20 optic discs from 20 normal subjects. The mean intraocular pressure was higher in the EG group when compared with POAG (p < 0.001). Although the mean disc areas in both groups were not significantly different, the mean initial NRR area to disc area ratio was significantly smaller in patients with EG (p < 0.001). At the initial diagnosis the most prominent NRR defects of the patients with POAG were at the inferotemporal and superotemporal sectors, followed by the temporal and nasal sectors. However, the NRR in the EG group was noticed to decrease diffusely without such a sectorial preference. There was no significant difference between the mean loss of the NRR to disc area ratio in both groups at the end of the follow-up period of 1 year (p > 0.05). The values of parapapillary chorioretinal atrophy areas in POAG and EG patients were not significantly different from each other, neither at the initial examination nor during the follow-up period (p > 0.05). Those results suggest that high intraocular pressure in eyes with EG may constitute a major risk for rapid and progressive glaucomatous optic disc damage.