Is exfoliation syndrome a sign of systemic vascular disease?

Exfoliation syndrome and exfoliation glaucoma: Current perspectives and clinical paradigms

Exfoliation syndrome and exfoliation glaucoma comprise a unique age-related ocular aggregopathy characterized by the accumulation of protein complex aggregates in different ocular structures. Recent literature and studies have expanded our knowledge of the clinical characteristic features, phenotypical variations, and molecular pathophysiology associated with disease onset or development of glaucoma. Despite years of studies on the various epidemiological, clinical, and molecular facets of the disease, the exact mechanism of disease onset, formation of aggregates, and the events that trigger the development of glaucoma marking irreversibility in the disease remains elusive. This review elaborates on the existing and new insights that we have gained over the years and highlights gaps in the knowledge about the disease that need future exploration.

Risk factors for exfoliation glaucoma - Current evidence and perspectives

Exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) represent a complex matrix of ocular age-related neurodegenerative changes. Numerous decades of research on this disease entity have highlighted the unique clinical features of ocular protein-complex aggregates, which lead to tissue dysfunction of the ocular outflow channels, leading to irreversible optic nerve damage and glaucoma. While genetic studies have reported several genes associated with XFS and XFG, numerous studies have shown their association with common systemic diseases such as ischemic heart disease, cerebrovascular accidents, and hypertension. Environmental factors are also reported to play a role in the disease pathogenesis by epigenetic control of gene expression and partly explain the difference in the prevalence rates of the disease process. Despite the identification of possible triggers for the disease onset or for the development of glaucoma, the exact mechanisms or the role of several reported risk factors in disease pathogenesis remain a mystery. This review comprehensively evaluated the several risk factors in XFS and XFG while discussing the interactive interplay between the risk factors that determine the disease onset or phenotype in XFS and XFG.

Exploring association between pseudoexfoliation syndrome and ocular aging

PURPOSE

Within a population-based follow-up study, to examine the 10-year incidence of pseudoexfoliation syndrome (PEX), possible risk factors for PEX and its association with ocular aging of the cornea, lens and retina.

METHODS

The baseline examination was conducted in 2006 on a random sample of 1,033 adult participants from Kaunas city (Lithuania) population of whom 631 had ophthalmic examination data at attendance of the 10-year follow-up in 2016. Detailed examination of the anterior and posterior segment of the eye was carried out. After diagnostic mydriasis PEX was diagnosed by the presence of typical grayish-white exfoliation material on the anterior capsule surface of the lens. The participants were divided to PEX and non-PEX groups.

RESULTS

PEX prevalence increased from 9.8 to 34.2% from baseline to 10-year follow-up. Nuclear cataract was common both in the PEX group (66.7%) and in those without PEX (72.2%), but this difference did not reach statistically significantly increased risk of developing cataract in those with PEX (OR 1.2; p = 0.61). Central corneal thickness (CCT) was thinner in the PEX group (529 ± 34 μm) and in the oldest group (525 ± 36 μm) (p < 0.001). Compared to baseline, corneal curvature (CC) became flatter in both groups (7.6 ± 0.27 vs 7.7 ± 0.26 mm; p < 0.001) during the follow-up, but the difference did not reach significance between groups. Corneal astigmatism was most commonly with-the-rule in both groups (37 (50.0%) vs 148 (68.5%); p > 0.05). Age, sex and PEX had no influence on age-related macular degeneration distribution.

CONCLUSION

The prevalence of PEX increased significantly with age in our population, with those with PEX having thinner and flatter corneae, but no difference in cataract and age-related macular degeneration characteristics.

Prediagnostic Plasma Metabolomics and the Risk of Exfoliation Glaucoma

Purpose

The etiology of exfoliation glaucoma (XFG) is poorly understood. We aimed to identify a prediagnostic plasma metabolomic signature associated with XFG.

Methods

We conducted a 1:1 matched case-control study nested within the Nurses' Health Study and Health Professionals Follow-up Study. We collected blood samples in 1989-1990 (Nurses' Health Study) and 1993-1995 (Health Professionals Follow-up Study). We identified 205 incident XFG cases through 2016 (average time to diagnosis from blood draw = 11.8 years) who self-reported glaucoma and were confirmed as XFG cases with medical records. We profiled plasma metabolites using liquid chromatography-mass spectrometry. We evaluated 379 known metabolites (transformed for normality using probit scores) using multiple conditional logistic models. Metabolite set enrichment analysis was used to identify metabolite classes associated with XFG. To adjust for multiple comparisons, we used number of effective tests (NEF) and the false discovery rate (FDR).

Results

Mean age of cases (n = 205) at diagnosis was 71 years; 85% were women and more than 99% were Caucasian; controls (n = 205) reported eye examinations as of the matched cases' index date. Thirty-three metabolites were nominally significantly associated with XFG (P < 0.05), and 4 metabolite classes were FDR-significantly associated. We observed positive associations for lysophosphatidylcholines (FDR = 0.02) and phosphatidylethanolamine plasmalogens (FDR = 0.004) and inverse associations for triacylglycerols (FDR < 0.0001) and steroids (FDR = 0.03). In particular, the multivariable-adjusted odds ratio with each 1 standard deviation higher plasma cortisone levels was 0.49 (95% confidence interval, 0.32-0.74; NEF = 0.05).

Conclusions

In plasma from a decade before diagnosis, lysophosphatidylcholines and phosphatidylethanolamine plasmalogens were positively associated and triacylglycerols and steroids (e.g., cortisone) were inversely associated with XFG risk.

Comparison of long-term results of trabeculectomy and phacotrabeculectomy in patients with pseudoexfoliation glaucoma and primary open-angle glaucoma: a single-center study

PURPOSE

To evaluate long-term surgical success and complications in pseudoexfoliation glaucoma (PEXG) and primary open-angle glaucoma (POAG) after trabeculectomy or phacotrabeculectomy.

METHODS

96 PEXG eyes and 114 POAG eyes who underwent primary trabeculectomy and phacotrabeculectomy were retrospectively evaluated considering intraocular pressure (IOP), the number of glaucoma medications, surgical success, and rate of complications. Two success criteria were used: Complete success comprised IOP of 5-18 mmHg and 20% reduction of baseline IOP without medication. Qualified success comprised IOP of 5-18 mmHg and 20% reduction of baseline IOP irrespective of medication. Success rates in PEXG and POAG groups, trabeculectomy and phacotrabeculectomy groups, and four groups divided according to surgery and etiology were analyzed via Kaplan-Meier survival analysis.

RESULTS

The complete and qualified success were not different between PEXG and POAG groups. The qualified success curves show a similar pattern among the four groups throughout the follow-up of 1,2,3,5,7 and 9 years. Baseline IOP and the number of medications were similar in all four groups (p = 0.275 and p = 0.209, respectively). IOP levels and the number of medications were not statistically different between the four groups during the follow-up of 2,5 and 7 years. The total number of complications and interventions were similar between PEXG and POAG groups (p = 0.258).

CONCLUSIONS

Phacotrabeculectomy is an effective procedure as trabeculectomy with similar surgical success rates and few surgical complications when it comes to treating PAOG and PEXG patients. Both approaches resulted in similar postoperative IOP levels and medication numbers in both groups.

Is pseudoexfoliation syndrome associated with vitreoretinal interface abnormalities?

BACKGROUND

To evaluate vitreoretinal interface abnormalities in patients with pseudoexfoliation (PEX) syndrome.

METHODS

This case-control study was performed in 136 patients diagnosed with unilateral PEX (PEX group) and 139 age- and sex-matched healthy volunteers (Control group). Both the affected and contralateral eyes were evaluated in the PEX group and the right eye was evaluated in the Control group. Vitreoretinal interface abnormalities and posterior vitreous detachment (PVD) were evaluated on optical coherence tomography (OCT) examination.

RESULTS

The incidences of incomplete and complete PVD were significantly higher in the affected than contralateral eye in the PEX group and in the right eye in the Control group (P = 0.009, P = 0.012 and P = 0.004, P = 0.017, respectively). The rates of 'no PVD' were significantly higher in the contralateral eye in the PEX group and the Control group compared to the affected eye in the PEX group (P = 0.003 and P = 0.001, respectively). The odds ratio for incomplete PVD was 3.1 in PEX eyes compared to the contralateral eye in the PEX group and 3.9 compared to the Control group. The rate of epiretinal membranes (ERMs) in the affected eye was significantly different from the contralateral eye in the PEX and Control groups (P < 0.001 and P < 0.001, respectively). The odds ratio for ERM in PEX eyes was 3.51 compared to the contralateral eye in the PEX group and 4.23 compared to the Control group. In the presence of incomplete PVD, the odds ratio for ERM development was 3.81 in PEX eyes.

CONCLUSIONS

We detected high rates of ERMs and incomplete PVD in patients with PEX. It is important to evaluate and follow up PEX cases in terms of vitreoretinal interface abnormalities.

Hemodynamics of the temporal and nasal short posterior ciliary arteries in pseudoexfoliation syndrome

PURPOSE

The aim of this study was to investigate blood flow changes in the temporal and nasal short posterior ciliary arteries (SPCAs) in pseudoexfoliation syndrome using color Doppler ultrasonography.

METHODS

This prospective clinical study included 67 eyes of 53 patients scheduled for cataract surgery. Pseudophakic eyes, eyes with traumatic cataract, were excluded. The demographic characteristic of the patients were recorded. Ocular blood flow was measured using 6-10 MHz Doppler ultrasound. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (Vm), and resistive index (RI) in the temporal and nasal SPCAs were determined for 39 eyes of 30 patients with pseudoexfoliation syndrome and cataract and a control group comprising 28 eyes of 23 patients with senile cataract.

RESULTS

Compared to the control group, patients with pseudoexfoliation syndrome had significantly lower PSV (8.85 ± 2.88 cm/s), EDV (3.21 ± 1.12 cm/s), and Vm (5.27 ± 1.98 cm/s) in the temporal SPCA (PSV P = .001; EDV P = .002; Vm P = .001). There was no difference in velocities in the nasal SPCA. RI of both the temporal and nasal SPCA did not differ statistically between the groups (temporal SPCA P = .517, nasal SPCA P = .752) CONCLUSION: There were significant decreases in temporal SPCA hemodynamic parameters in patients with pseudoexfoliation syndrome. These findings suggest that temporal SPCA ocular blood flow measurements have greater diagnostic value than those of the nasal SPCA.

Link of ocular pseudoexfoliation syndrome and vascular system changes: results from 10-year follow-up study

PURPOSE

To examine the 10-year incidence of the pseudoexfoliation syndrome (PEX) in adults in a population-based follow-up study, to determine its link with vascular diseases, and to identify possible risk factors of the PEX.

METHODS

The baseline examination was performed in 2006 on a random sample of 1033 participants from Kaunas city (Lithuania) population. In 2016, a follow-up study of 686 participants who returned for the examination was conducted. The respondents filled out a questionnaire, an ophthalmological examination was performed, and the presence of vascular diseases was determined by the anamnesis and electrocardiogram evaluation data. Binary univariate and multivariate logistic regression analyses were conducted with the PEX and vascular diseases as predictors, controlling for age. Odds ratios (OR) and 95% confidence intervals of OR were calculated for the risk of new PEX cases.

RESULTS

During 10 years, the prevalence of the PEX in the study population increased from 10.3 to 34.2%. The rates of ischemic heart disease (IHD) and IHD combined with stroke were significantly higher in the PEX subjects than in the non-PEX subjects. The risk of the PEX among persons with IHD was, on the average, by 1.5-fold higher, and among those with IHD and stroke, on the average, by 1.6-fold higher as compared to persons without the aforementioned pathologies (accordingly, p = 0.014 and p = 0.010).

CONCLUSION

The prevalence of the PEX increased significantly with age. The risk of the PEX was significantly higher among persons with IHD and even higher among persons with IHD and stroke. In the future, a greater understanding of the cardiovascular, metabolic, and environmental components associated with the PEX may lead to more specific lifestyle-related preventive strategies to decrease the disease burden.

What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago?

Exfoliation syndrome (XFS) is a systemic disease with significant ocular manifestations, including glaucoma and cataract. The disease impacts close to 70 million people globally and is now recognised as the most common identifiable cause of open-angle glaucoma. Since the discovery of XFS 100 years ago by Dr John G. Lindberg, there has been considerable advancement in understanding its pathogenesis and resulting clinical implications. The purpose of this paper is to summarise information regarding the epidemiology, pathophysiology, ocular manifestations and systemic associations of XFS with the objective of sharing clinical pearls to assist in early detection and enhanced management of patients.

[Pseudoexfoliation syndrome and pseudoexfoliation glaucoma]

Pseudoexfoliation syndrome is an age-related systemic disease that mainly affects the anterior structures of the eye. Despite a worldwide distribution, reported incidence and prevalence of this syndrome vary widely between ethnicities and geographical areas. The exfoliative material is composed mainly of abnormal cross-linked fibrils that accumulate progressively in some organs such as the heart, blood vessels, lungs or meninges, and particularly in the anterior structures of the eye. The exact pathophysiological process still remains unclear but the association of genetic and environmental factors are thought to play a role in the development and progressive extracellular accumulation of exfoliative material. Hence, LOXL1 gene polymorphisms, responsible for metabolism of some components of elastic fibers and extracellular matrix, and increased natural exposure to ambient ultraviolet or caffeine consumption have been associated with pseudoexfoliation syndrome. Ophthalmological manifestations are commonly bilateral with an asymmetric presentation and can lead to severe visual impairment and blindness more frequently than in the general population, mainly related to glaucoma and cataract. Pseudoexfoliation glaucoma is a major complication of pseudoexfoliation syndrome and represents the main cause of identifiable glaucoma worldwide. Visual field progression is more rapid than that observed in primary open angle glaucoma, and filtering surgery is more frequently required. Nuclear cataract is more frequent and occurs earlier than in the general population. Owing to poorer pupil dilation and increased zonular instability, cataract surgery with pseudoexfoliation is associated with a 5- to 10-fold increase in surgical complications compared to cataract surgery without pseudoexfoliation. Some specific treatments targeting production, formation or accumulation of exfoliative material could improve the prognosis of this syndrome.

Chosen Vascular Risk Markers in Pseudoexfoliation Syndrome: An Age-Related Disorder

Purpose

To evaluate lipids and C-reactive protein serum levels in patients with pseudoexfoliation syndrome (PEX) in the Polish population.

Methods

96 patients were studied with PEX and 79 control subjects. Total cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, non-HDL-cholesterol and CRP serum levels, and TG/HDL-C and TC/HDL-C indexes were assessed.

Results

There were no significant differences in concentration of lipids and values of TC/HDL-C, TG/HDL-C, and non-HDL-C between PEX and control groups. High-sensitivity C-reactive protein was not increased in patients with PEX.

Conclusions

Our results cast doubt on the opinion on the possible PEX and vascular diseases relation. Further studies on this subject are mandatory.

Choroidal Vessel Diameters in Pseudoexfoliation and Pseudoexfoliation Glaucoma Analyzed Using Spectral-Domain Optical Coherence Tomography

PURPOSE OF THE STUDY

The purpose of the study was to analyze choroidal vessel diameters in pseudoexfoliation (PXF) and pseudoexfoliation glaucoma (PXFG) using spectral-domain optical coherence tomography (SD-OCT).

MATERIALS AND METHODS

Fifty patients (100 eyes) with PXF and PXFG who underwent high-definition 1-line raster SD-OCT imaging at New England Eye Center, Boston, were retrospectively identified and divided into unilateral PXFG (26 patients, 52 eyes), unilateral PXF (4 patients, 8 eyes), bilateral PXFG (4 patients, 8 eyes), and bilateral PXF (16 patients, 32 eyes). Eyes with concomitant chorioretinal pathology, history of shunting/filtering for glaucoma, and significant anisometropia were excluded. SD-OCT scans were divided into subfoveal, central, and peripheral zones and choroidal vessel diameters were measured.

RESULTS

In patients with unilateral PXFG, mean choroidal vessel diameter was 12.9 μm smaller in the affected eyes when compared with their contralateral eyes (45.7 vs. 58.6 μm; P<0.0001) with the greatest reduction (16.6 μm) in the subfoveal zone (49.0 vs. 65.6 μm; P<0.0001). In patients with unilateral PXF, the mean choroidal vascular diameter was 13.3 μm smaller in the affected eyes when compared with their contralateral eyes (42.8 vs. 56.1 μm; P=0.02). As expected, no significant difference was observed between the 2 eyes of patients with bilateral PXFG (45.5 vs. 45.7 μm; P=0.95) and bilateral PXF (51.4 vs. 50.2 μm; P=0.52).

CONCLUSIONS

Choroidal vessel diameters are smaller in the affected eyes of patients with unilateral PXF and PXFG when compared with their contralateral unaffected eyes. These changes appear to be independent of the presence or absence of glaucoma. Future studies may identify the choroidal vascular changes and their relationship with the pathogenesis of these conditions.

Comparison of Rotational Thromboelastography Findings in Pseudoexfoliation Syndrome Patients and Healthy Controls

PURPOSE

Rotational thromboelastography (ROTEM) is a useful test for studying the characteristics of fibrin clot formation. As patients with pseudoexfoliation (PEX) have an increased risk for thrombotic events, clot-forming dysfunction may play a role. The aim of this study is to compare ROTEM findings in PEX syndrome patients with age-matched and sex-matched healthy controls.

PATIENTS AND METHODS

A total of 21 patients with PEX syndrome and 22 age-matched and sex-matched healthy controls were included. All study participants underwent detailed ophthalmologic and systemic medical examination, including blood pressure measurement, hemoglobin-hematocrit levels, platelet count, coagulation parameters including prothrombin time, activated partial thromboplastin time, fibrinogen levels, and D-dimer levels. Peripheral blood samples were collected and analyzed with ROTEM Coagulation Analyzer.

RESULTS

The mean age of patients with PEX and controls was 66.5±8.3 and 65.9±9.5 years, respectively (P=0.7). The 2 groups did not differ with respect to age, sex, hemoglobin, hematocrit, platelet numbers, prothrombin time, activated partial thromboplastin time, fibrinogen levels, D-dimer levels, and glucose levels. When extrinsic thromboelastometry results were analyzed, PEX patients showed a significantly decreased clotting time when compared with healthy controls (79.8 vs. 98.0 s; P=0.01), indicating faster clot formation. Other ROTEM parameters did now show any difference between the 2 groups.

CONCLUSIONS

PEX patients showed faster clotting time when compared with healthy controls. This fibrin clot formation dysfunction may lead to vascular thrombotic events in these patients. Further studies are needed to elucidate the exact underlying mechanism of thrombosis seen in PEX patients.

Immunohistochemical analysis of microsomal glutathione S-transferase 1 and clusterin expression in lens epithelial cells of patients with pseudoexfoliation syndrome

Pseudoexfoliation syndrome (PEX) is an age-associated, sight disorder affecting elastic fibers in the eye and visceral organs but its exact etiology remains unknown. The purpose of the current study was to determine the morphology and ultrastructure of lens epithelial cells (LECs), and to use immunohistochemistry to examine localization of microsomal glutathione S-transferase 1 (MGST1) and clusterin. Anterior lens capsules were obtained from 24 patients (13 PEX and 11 controls) who underwent phacoemulsification. Immunohistochemistry was performed, using antibodies against MGST1 and clusterin, to determine their expression. The morphology and ultrastructure of LECs were evaluated by light and transmission electron microscopy, respectively. The PEX LECs were characterized by significantly lower MGST1 (P=0.0001) and clusterin expression (P=0.0005) compared with the control group patients. PEX LECs were also observed to have significantly increased thickness compared with the control group patients (P=0.0002). The current findings suggest that low MGST1 and clusterin expression levels may be an early clinical indicator of PEX, and that oxidative stress may serve an important role, but that the specific etiology of this disease has yet to be revealed.

The prevalence of exfoliation syndrome in Turkey

PURPOSE

To investigate the prevalence of the exfoliation syndrome and its relationship with ocular and cardiovascular diseases in the Central Anatolia region of Turkey.

METHODS

This cross-sectional and population-based study was conducted at the Sivas Province among the population aged 40 years and over. The diagnosis of XFS was made when exfoliative material was found on the anterior lens capsule or iris on slit-lamp examination. The subjects were divided into an XFS group and a non-XFS group according to the presence of exfoliative material, and the groups were compared for the presence of glaucoma, cataract, age-related macular degeneration, phacodonesis, hypertension, diabetes mellitus, coronary artery disease, smoking and alcohol-use frequency.

RESULTS

XFS was present in 63 subjects consisting of 42 males (8.0%) and 21 females (3.6%) for an overall rate of 5.7% (95% CI: 0.054-0.060). Once we adjusted the values for age, we found a statistically significant relationship of increased age and male gender with the presence of XFS (p = 0.001, p = 0.027, respectively). The relationship between XFS and glaucoma, cataract and phacodonesis was found to be statistically significant (p = 0.001). No relationship was found between exfoliation syndrome and hypertension, diabetes mellitus and coronary artery disease.

CONCLUSION

The prevalence of exfoliation syndrome was 5.7% in this population-based study. There was a statistically significant relationship between XFS and advancing age and male gender.

Ocular pseudoexfoliation syndrome and life span

Background

To compare life span of persons with and without ocular pseudoexfoliation syndrome (PES).

Methods

The study is based on an epidemiological survey conducted in Sør-Trøndelag county, Norway, in 1985–86. All inhabitants over 64 years of age (2109 individuals) were invited. Mortality information was obtained from The Norwegian Institute of Public Health in 2014, by which time 99% of the participants were deceased.

Results

When adjusting for age and gender, life span was not statistically different in persons with and without PES. Following the diagnosis of PES, patients' survival was up to, and beyond, 30 years.

Conclusions

Our observations suggest that, despite all the systemic aberrations reported in persons with ocular PES, none or only marginal functional changes are caused in extraocular organs and tissues. The present study supports the notion that systemic PES is not a life-threatening condition.

•

Over the years several attempts have been made to link pseudoexfoliation syndrome to a number of serious systemic diseases.

•

The present study shows no difference in life span between persons with and without pseudoexfoliation in our cohort.

Retinal vessel diameters and their correlation with retinal nerve fiber layer thickness in patients with pseudoexfoliation syndrome

AIM

To compare retinal artery-vein diameters (RAVDs) of patients with pseudoexfoliation (PSX) syndrome with healthy controls and investigate the correlations between retinal nerve fiber layer (RNFL) thickness parameters and RAVDs.

METHODS

Seventeen eyes with PSX and 17 eyes of age-matched controls were included in the study. All participants underwent routine ophthalmological examination, Humphrey visual field and RNFL examination by using Stratus OCT. Retinal images were obtained by using a retinal camera (Topcon 501X). RAVDs were measured from inferior nasal, inferior temporal, superior nasal and superior temporal arcuates by using IMAGEnet software. Superior, inferior, nasal, temporal and average RNFL thicknesses were recorded. RAVDs and RNFL parameters in groups and correlations were analyzed by Mann-Whitney U and Spearmann correlation tests.

RESULTS

Only inferior quadrant and average RNFL thickness were detected thinner in the PSX group compared with control group (P=0.009, P=0.038, respectively). No statistically significant difference regarding RAVDs was found between two groups.

CONCLUSION

RAVDs seems to be comparable in the PSX and control group. RNFL is thinner in the inferior quadrant in the PSX group. RNFL thickness and RAVDs show significant correlations in both groups. This correlation doesn't seem to be specific to PSX.

Pseudoexfoliation syndrome and coronary artery ectasia

AIMS

To determine whether pseudoexfoliation syndrome is associated with coronary artery ectasia or not.

METHODS

This cross-sectional study was undertaken at Bulent Ecevit University's Ophthalmology Department with the participation of the Cardiology Department. Eighty consecutive patients who underwent coronary angiography and were classified into two groups-those diagnosed with a normal coronary artery (n=40) and those diagnosed with coronary artery ectasia (n=40)-were included in the study. Pseudoexfoliation was diagnosed if typical exfoliation material was found to be present on the anterior surface of the lens, the iris, or at the pupillary border on slit-lamp examination. Age, sex, presence of pseudoexfoliation material, hypertension, diabetes mellitus, hyperlipidemia rates, cigarette smoking history, and family history of coronary artery disease were compared between the two groups. The continuous variables were compared by using the independent sample t-test or the Mann-Whitney U-test, and the categorical variables were compared using Pearson's χ(2)-test or Fisher's Exact χ(2)-test for the two groups.

RESULTS

There was no difference in demographic data of both groups. The presence of pseudoexfoliation material was more common in patients with coronary ectasia compared with controls [(n=21 (52.5%) vs n=8 (20%), P=0.005)]. In all patients, there was a higher glaucoma rate in the patients with pseudoexfoliation syndrome [n=7 (24.1%), 6 CAE (+), 1 CAE (-)] than in the normal patients [n=2 (3.9%), 2 CAE (-)] (P=0.010).

CONCLUSIONS

In this study, we found a possible association of pseudoexfoliation and coronary artery ectasia. Coronary artery ectasia patients had higher prevalence of pseudoexfoliation.

Ocular pseudoexfoliation syndrome and vascular disease: a systematic review and meta-analysis

Objective

Many studies have assessed the association between ocular pseudoexfoliation syndrome (PEX) and vascular disease and produced controversial results. We performed a meta-analysis of epidemiologic studies to evaluate this relationship.

Methods

Eligible studies that reported the incidence of vascular disease among PEX and control groups were identified via computer searches and reviewing the reference lists of the key articles. The summary odds ratio (OR) and 95% confidence interval (CI) were pooled using a random-effects model. Meta-regression to assess heterogeneity by several covariates and a subgroup analysis on study design and population were performed. Publication bias was tested by Begg's funnel plot and Egger's regression test.

Results

Sixteen eligible studies involving 8,533 PEX patients and 135,720 control patients were included in the meta-analysis. All studies were performed primarily in whites with a mean age between 54.7 and 77.1 years. The overall combined ORs for patients with PEX compared with the reference group were 1.72 (95% CI: 1.31 to 2.26) for any vascular disease, 1.61 (95% CI: 1.22 to 2.14) for coronary heart disease, 1.59 (95% CI: 1.12 to 2.23) for cerebrovascular disease, and 2.48 (95% CI: 1.30 to 4.72) for aortic aneurysm. There was evidence of statistical heterogeneity; however, subgroup and sensitivity analyses showed this result to be robust. No evidence of publication bias was observed.

Conclusions

The overall current literature suggests that PEX was associated with increased risk of vascular disease. Because of the limitations of the included studies and meta-analysis, the findings need to be confirmed in future research via well-designed cohort studies.

Prevalence and early detection of abdominal aortic aneurysm in pseudoexfoliation syndrome and pseudoexfoliation glaucoma

PURPOSE

The goals of this study were to demonstrate the frequency of infrarenal abdominal aortic aneurysm (AAA) in patients with pseudoexfoliation (PEX) syndrome (PEXS) and PEX glaucoma (PEXG), and to determine whether limited screening for AAA in specific subgroups of patients with PEX is reasonable and justifiable.

MATERIALS AND METHODS

This prospective study comprised 60 patients with PEXS and 60 with PEXG (examined group), and 60 patients with primary open-angle glaucoma (POAG) and 60 with cataract (control group). Clinical ophthalmic examination included slit-lamp biomicroscopy of the anterior segment and direct slit-lamp gonioscopy (using a Goldmann three-mirror lens) of the anterior chamber angle. All patients underwent routine Color Doppler duplex ultrasonography of the infrarenal aorta and iliac arteries.

RESULTS

There was a statistically significant difference (p < 0.05) between the PEXG group and control group vis-a-vis presence of AAA, which occurred more frequently in patients with greater amounts of angle pigmentation (p < 0.05). Univariate logistic regression analysis indicated statistically significant associations between AAA and PEX (p < 0.01), angle pigmentation (p < 0.05), gender (p < 0.01), diabetes mellitus (DM) (p < 0.05), and arterial hypertension (AHT) (p < 0.01). Multivariate regression analysis, adjusted to gender and age, showed that the most important clinical parameters related to AAA in patients with PEXS and PEXG are gender, presence of PEX, DM, and AHT (p < 0.05).

CONCLUSION

The frequency of AAA is significantly higher in patients with PEXS and PEXG than in patients with POAG or cataract. Restricted screening for AAA in male PEXS patients, who also have elevated degrees of angle pigmentation, arterial hypertension, and DM, is clinically warranted.

Endothelial cell markers in patients with pseudoexfoliation syndrome

The aim of the study was the assessment of the von Willebrand antigen (vWF Ag), E-selectin, and P-selectin concentration in blood plasma of patients with pseudoexfoliation syndrome (PEX). The group studied comprised 30 patients with PEX, aged from 50 to 86 years (mean 73, SD ± 8 years). Patients with cardiovascular and cerebrovascular diseases, diabetes mellitus, infectious disease, cancer, renal or liver insufficiency, connective tissue disease, current smoking, and hormone, antiplatelet, hypolipidemic, antioxidant, or antihypertensive drug therapy were excluded from the study. Each subject underwent a complete ophthalmological examination. Venous blood samples from the cubital vein were taken into sodium citrate solution. VWF Ag, sP-selectin, and sE-selectin concentration were determined by a commercially available enzyme-linked immunosorbent assay (MedSystems, Diagnostica Stago/Roche, R&D). Concentrations of vWF Ag, soluble E-selectin, and soluble P-selectin in blood plasma in the study group were compared with the levels in blood plasma in the control group. No significant differences were found between the groups. Our results indicate that there might be no correlation between PEX and such endothelial cell markers as vWF Ag, sP-selectin, and sE-selectin concentrations. Since the study size is limited, further investigations to confirm that there is no association between endothelial dysfunction in PEX and risk of future cardiovascular disease are necessary.

High prevalence of pseudoexfoliation syndrome and its complications in Tarragona in northeast Spain

PURPOSE

To determine the prevalence of pseudoexfoliation syndrome (PEX) in our health area, in 4 counties of Tarragona, and its involvement in the health status of the population.

METHODS

This was a cross-sectional study of a sample of 2,342 inhabitants aged = 60 years, randomly selected from the population census. Subjects were classified in 3 groups according to age (group 1 = 60-69 years, group 2 = 70-79 years, group 3 = over 80 years). The diagnosis of PEX was made in all cases by the same ophthalmologist, using biomicroscopic and slit-lamp evaluation. Corneal endothelial study was made by specular microscope.

RESULTS

The prevalence of PEX was 309/2,342 patients (13.19%), unilateral in 219/309 (70.87%). The prevalence of PEX in patients with open-angle glaucoma was 29.48%. Changes in corneal endothelium were higher in patients with PEX, with lower cell density and hexagonality percentage, with higher coefficient of variation, significant in age groups 2 and 3. The prevalence of cataract in patients with PEX was 80.58%, versus 54.64% in patients without PEX. Complications of cataract surgery were higher in patients with PEX and postoperative corneal edema was best correlated with a low hexagonality percentage. No systemic cardiovascular diseases were significant in patients with PEX.

CONCLUSIONS

In our health district area, a high prevalence of PEX exists. A more extensive study of the causes of these differences is needed, including analysis of the genetic makeup of the population.

Geographic and climatic factors associated with exfoliation syndrome

OBJECTIVE

To identify geographic and climatic risk factors associated with exfoliation syndrome (ES).

METHODS

A retrospective study of 626 901 eye care recipients, dating from 2001 to 2007 from 47 US states in a managed care network. Incident ES cases-patients (N = 3367) were identified by using billing codes. We assessed the risk of ES by geographic latitude tier in the continental United States and assigned state-level climatic data (eg, ambient temperature, elevation, and sun exposure) according to patients' residential location. The hazard of ES was calculated by using multivariable-adjusted Cox proportional hazards regression models.

RESULTS

Compared with middle-tier residence, northern-tier residence (above 42°N) was associated with an increased hazard of ES (adjusted hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.94-2.35). Southern-tier (below 37°N) was associated with a reduced hazard of ES (HR, 0.83; 95% CI, 0.75-0.93). Excluding whites did not change these associations. After adjustment for joint environmental effects, for every 1° increase in July high temperature, the hazard of ES decreased by 9% (HR, 0.91; 95% CI, 0.89-0.93); for every 1° increase in January low temperature, the hazard decreased 3% (0.97; 0.96-0.98). For each additional sunny day annually, the hazard increased by 1.5% (HR, 1.02; 95% CI, 1.01-1.02) in locations with average levels of other climatic factors.

CONCLUSION

Ambient temperature and sun exposure may be important environmental triggers of ES.

Systemic disease associations of familial and sporadic glaucoma: the Glaucoma Inheritance Study in Tasmania

BACKGROUND

This aim of this study was to compare the prevalence of various disease-associated and potentially modifiable risk factors between people with familial and sporadic forms of primary open angle glaucoma (OAG).

METHODS

A cross-sectional, retrospective study design was utilized. A detailed questionnaire enquiring about knowledge of family history, demographic data, current medications, and medical history of systemic disorders was administered. Where possible, living relatives were examined for signs of OAG.

RESULTS

A total of 3,800 potential patients with OAG were identified, of whom 2062 were examined. One thousand twelve (59.5%) subjects were found to have familial OAG, and 688 (40.5%) subjects had no known or identified relative with OAG (sporadic glaucoma). One thousand forty-two unaffected family members examined. A past history of migraine was found more often with familial OAG (OR: 1.67 95% CI: 1.15-2.42). This effect was primarily driven by patients who had a first-degree relative also affected by OAG. Following adjustment for male gender and the age at review, the presence of atherosclerosis was also found to be more common in patients with familial glaucoma than in people with sporadic disease (OR: 1.42 95% CI: 1.05-1.92). No significant difference in the prevalence of hypertension, Raynaud's phenomenon, diabetes mellitus or thyroid disease was identified.

CONCLUSIONS

Patients with a known relative affected by OAG were statistically significantly more likely to have a past history for migraine or presence of atherosclerosis compared to people with no known affected relative. An understanding of such differences and systemic comorbidities will be useful for further work investigating the underlying molecular mechanisms of this disease.

From epidemiology to lysyl oxidase like one (LOXL1) polymorphisms discovery: phenotyping and genotyping exfoliation syndrome and exfoliation glaucoma in Iceland

The first Icelandic articles on exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) appeared some 35 years ago in 1974. Articles since then have included epidemiology, pedigree-based and twin-studies as well as investigations into XFG response to medical therapy and XFS/XFG genetics. All studies found XFS/XFG to be common in Iceland and to be age-related. The Reykjavik Eye Study (RES), a population-based epidemiological study, was first conducted in 1996. The RES found that XFS and XFG prevalence in patients aged 50 years and older was 11% and that XFS/XFG was more common in women than in men. These results were confirmed in 5- and 12-year incidence studies that also suggested that detailed characterization of the phenotype is important, including pupil dilation. In the RES, eyes with XFS were found to be clinically unilateral in about half of cases and to have higher mean intraocular pressure (IOP) than non-XFS eyes. However, XFS was not found to be associated with central corneal thickness, corneal curvature, anterior chamber depth, lens thickness, lens opacification or optic disc morphology. About 15% of persons with XFS had XFG, and XFG eyes had higher risk of developing visual impairment and blindness than eyes with primary open-angle glaucoma. The first genetic studies on Icelanders, conducted about 12 years ago, were linkage studies and were unsuccessful in discovering the genetics behind XFS/XFG. However, in 2007 a genome-wide association study in Iceland using more than 300 000 markers [single nucleotide polymorphisms (SNPs)] on a relatively small number of patients did discover that lysyl oxidase like 1 (LOXL1) on chromosome 15q24 is a major gene for XFS/XFG. These results have now largely been replicated world-wide.