Renal artery stenosis and abdominal aorta aneurysm in patients with pseudoexfoliation syndrome. Eye (Lond). 2013;27:735-741. [PMID: 23579404 DOI: 10.1038/eye.2013.56]

Systemic Vascular Parameters in Ocular Pseudoexfoliation

Background Pseudoexfoliation syndrome (PEX) is characterized by a dandruff-like substance in the anterior chamber, composed of various glycoproteins that have an unclear origin. Its deposition is observed on the pupillary margin, lens zonules, and trabecular meshwork. Proteomic studies have identified numerous proteins in the affected individuals, suggesting associations with systemic conditions like heart disease, stroke, and Alzheimer's disease. However, the systemic associations of PEX remain inconclusive, particularly in regions like southern India. Materials and methods A cross-sectional study was conducted on 114 participants. Pseudoexfoliation was graded as mild, moderate, and severe as per standard photographic grading. Systemic examinations included blood pressure measurements, electrocardiography (ECG), and blood investigations for serum lipid profile, fasting and postprandial blood sugar levels, and serum C-reactive protein levels. Small incision cataract surgery was performed for all the patients. Intraoperative complications and postoperative status were recorded. Results Thirty-eight patients (33.3%) had mild PEX, 44 (38.6%) had moderate PEX, and 32 (28.1%) had severe PEX. Hypertension was present in 54 participants (47.4%), diabetes in 21 (18.4%), coronary artery disease in nine (7.9%), and cerebrovascular accidents in three (2.6%). The mean systolic blood pressure was 140.39 mmHg and the mean diastolic blood pressure was 90.37 mmHg. Systolic blood pressure exceeded 140 mmHg in 29 participants (90.6%) with severe PEX, while diastolic blood pressure surpassed 90 mmHg in 26 participants with severe PEX, both with a p-value of 0.001. Mean fasting and postprandial blood sugar levels were 103.80 ± 31.81 mg/dl and 131.72 ± 48.24 mg/dl, respectively. Serum lipid profiles showed mean low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), cholesterol, and triglyceride levels of 103.00 ± 34.49 mg/dl, 29.04 ± 15.51 mg/dl, 172.73 ± 43.34 mg/dl, and 129.33 ± 64.65 mg/dl respectively. Electrocardiographic results indicated that 54 participants (47.37%) had abnormal ECG including rate abnormality in 13.2%, conduction defects in 12.3%, ischemic changes in 10.5%, and structural defects in 11.4%. Eighty-seven percent of patients had non-dilating pupils and iris atrophy, 13.2% had zonular dialysis and intraoperatively, 78% had capsulorhexis extension, 49.12% had difficult nucleus prolapse, and 28.95% had posterior capsular rent. Conclusion This study highlights the significantly elevated parameters of systemic vascular diseases in PEX patients, like elevated blood pressure and more frequent cardiac anomalies, emphasizing the need for comprehensive systemic evaluation and careful preoperative assessment for ocular comorbidities.

Glaucoma, Pseudoexfoliation and Hearing Loss: A Systematic Literature Review

Purpose: To investigate the relationship between glaucoma, pseudoexfoliation and hearing loss (HL). Methods: A systematic literature search following PRISMA guidelines was conducted using the PubMed, Embase, Scopus and Cochrane databases from 1995 up to 28 August 2023. Results: Thirty studies out of the 520 records screened met the inclusion criteria and were included. Most articles (n = 20) analysed the association between pseudoexfoliation syndrome (XFS) and HL, showing XFS patients to have higher prevalence of sensorineural hearing loss (SNHL) at both speech frequencies (0.25, 0.5, 1 and 2 kHz), and higher frequencies (4 and 8 kHz) compared to controls in most cases. No significant differences in prevalence or level of HL between XFS and pseudoexfoliative glaucoma (XFG) were detected in most studies. Eight articles analysed the relationship between primary open-angle glaucoma (POAG) and HL. Overall, a positive association between the two conditions was highlighted across all studies except for two cases. Similarly, articles focusing on NTG and HL (n = 4) showed a positive association in most cases. The role of autoimmunity and, in particular, the presence of antiphosphatidylserine antibodies (APSA) in patients with NTG and HL suggested an underlying autoimmune or vascular mechanism contributing to their pathogenesis. Only one study analysed the relationship between angle-closure glaucoma (ACG) and HL, showing higher incidence of ACG in patients with SNHL compared to normal hearing controls. Conclusions: Most studies detected an association between XFS and HL as well as POAG/NTG/ACG and HL, suggesting the presence of a similar pathophysiology of neurodegeneration. However, given the strength of the association of XFS with HL, it remains unclear whether the presence of XFG is further associated with SNHL. Further research specifically targeted to assess the correlation between glaucoma, XFS and HL is warranted to provide a more comprehensive understanding of this association.

Abdominal aortic aneurysm and exfoliation syndrome in Utah

PURPOSE

A pilot study of electronic medical records (EMR) in Utah was undertaken to investigate exfoliation syndrome and exfoliation glaucoma (XFS/XFG) in abdominal aortic aneurysm (AAA) patients. In a subsequent retrospective cohort study of Utah XFS/XFG patients and population controls, the risk of AAA was examined.

METHODS

EMR of a statewide healthcare population were obtained from the Utah Population Database (UPDB) which links decades of medical records with Utah demographic and vital records data. In a pilot study, 7167 patients ages ≥40 years identified with AAA diagnosed from 1996 to 2015, based on International Classification of Diseases (ICD) version 9/10 codes, were included. A univariable hazards model was used to determine the risk of XFS/XFG in AAA patients. An XFS/XFG outcome based on ICD 9/10 codes in AAA patients and in 5:1 sex- and age-matched non-AAA controls was determined. A retrospective cohort of 3412 XFS/XFG patients ages ≥50 years diagnosed from 1996 to 2020 and 10 227 3:1 sex- and age-matched controls who underwent ≥1 dilated eye examination(s) were recently identified and updated diagnoses of AAA were obtained. Multivariable logistic regression was used to estimate AAA risk in XFS/XFG patients compared with controls. In a subset of XFS/XFG patients, chart reviews were conducted to confirm clinically diagnosed AAA.

RESULTS

In the AAA pilot, 20 patients (0.3%) and 118 controls (0.3%) developed XFS/XFG, respectively. We observed no increased risk of XFS/XFG in AAA patients compared with non-AAA-matched controls (HR = 0.99, 95% CI 0.6-1.6). Among XFS/XFG study patients and controls, 122 patients (3.6%) and 376 controls (3.7%) had an AAA diagnosis. We likewise observed no increased risk of AAA in XFS/XFG patients (OR = 0.97, 95% CI 0.8-1.2). In 14 XFS/XFG patients with an ICD 9/10 diagnosis of AAA who underwent chart review, a clinical diagnosis of AAA was confirmed in 9 patients (64.3%).

CONCLUSION

Our findings do not support an association between AAA and XFS/XFG.

Dermatological Findings in Glaucoma Patients: Comparison Between Pseudoexfoliative and Primary Open-angle Glaucoma

Purpose

To compare the frequency of dermatological manifestations between patients with pseudoexfoliative glaucoma and those with primary open-angle glaucoma.

Methods

A cross-sectional study was done on all consecutive pseudoexfoliative glaucoma (PEXG) and primary open-angle glaucoma (POAG) patients evaluated in a tertiary eye hospital during the study period. Eligible patients were referred to the dermatology department for complete skin, hair, nail, and mucosal examinations.

Results

Twenty-one patients in the PEXG group and 26 patients in the POAG group were included in this study. The most common skin manifestations in the study were seborrheic dermatitis, dry skin, and cherry angioma. The frequency of lentigines was significantly higher in the PEXG patients than in the POAG group (P = 0.013). More than half of the study population had seborrheic dermatitis (57.1% and 61.5% in the PEXG and POAG groups, respectively); however, the difference between the groups was not statistically significant (P = 0.775). Similarly, the frequencies of skin dryness, cherry angioma, nevus, psoriasis, contact dermatitis, itching, seborrheic keratoses, notalgia paresthetica, and vitiligo in the two groups were not statistically significantly different (P > 0.1 for all comparisons). There was no significant association between the frequency of the investigated skin manifestations and patients' age, visual acuity, intraocular pressure, and cup-to-disc ratio.

Conclusion

Integumentary system disorders are pervasive in glaucoma patients, and dermatologic evaluation in glaucoma patients should be considered for diagnostic and therapeutic purposes.

Towards preventing exfoliation glaucoma by targeting and removing fibrillar aggregates associated with exfoliation syndrome

Exfoliation syndrome presents as an accumulation of insoluble fibrillar aggregates that commonly correlates with age and causes ocular complications, most notably open-angle glaucoma. Despite advances in understanding the pathogenesis and risk factors associated with exfoliation syndrome, there has been no significant progress in curative pharmacotherapy of this disease. It is thought that the ability to target the fibrillar aggregates associated with exfoliation may offer a new therapeutic approach, facilitating their direct removal from affected tissues. Phage display techniques yielded two peptides (LPSYNLHPHVPP, IPLLNPGSMQLS) that could differentiate between exfoliative and non-affected regions of the human lens capsule. These peptides were conjugated to magnetic particles using click chemistry to investigate their ability in targeting and removing exfoliation materials from the anterior human lens capsule. The behavior of the fibrillar materials upon binding to these magnetic particles was assessed using magnetic pins and rotating magnetic fields of various strengths. Ex vivo studies showed that the magnetic particle-peptide conjugates could generate enough mechanical force to remove large aggregates of exfoliation materials from the lens capsule when exposed to a low-frequency rotating magnetic field (5000 G, 20 Hz). Biocompatibility of targeting peptides with and without conjugated magnetic particles was confirmed using MTT cell toxicity assay, live/dead cell viability assay, and DNA fragmentation studies on primary cultured human trabecular meshwork cells. This is a novel, minimally invasive, therapeutic approach for the treatment of exfoliation glaucoma via the targeting and removal of exfoliation materials that could be applied to all tissues within the anterior segment of the eye.

Hearing Loss in Exfoliation Syndrome: Systematic Review and Meta-Analysis

OBJECTIVE

To determine if exfoliation syndrome (XFS) is associated with hearing loss (HL) or vestibular dysfunction.

DATA SOURCES

PubMed, Scopus, CINAHL, and Cochrane Library through April 1, 2022.

REVIEW METHODS

Two reviewers independently screened abstracts, selected articles for inclusion, and extracted data. Studies included for qualitative analysis conducted audiometric, tympanometric, or vestibular evaluations on all subjects.

RESULTS

Twenty-one publications (1148 patients with XFS and 1212 controls) were included in the systematic review, and 16 publications (968 patients with XFS and 1147 controls) in the meta-analysis. Greater severity of HL was seen for patients with XFS compared to controls across all frequencies (odds ratio [OR] 8.8 [7.3-10.2]). Patients with XFS were more likely to have moderate to profound sensorineural HL (OR 1.8 [1.3-2.5]), and less likely to have none to mild HL (OR 0.34 [0.17-0.67]) or no HL (OR 0.37 [0.28-0.50]). Three studies found patients with XFS had lower tympanometric peaks. Two studies found that abnormal vestibular testing results could be more common for patients with XFS.

CONCLUSIONS

HL is associated with XFS. A sensorineural component to HL is confirmed, and mixed HL is possible. Given the high prevalence and infrequent diagnosis of XFS, the authors hypothesize that the current understandings of presbycusis might be improved by further investigation in XFS. Laryngoscope, 2022.

Inhibitory and Agonistic Autoantibodies Directed Against the β2-Adrenergic Receptor in Pseudoexfoliation Syndrome and Glaucoma

Pseudoexfoliation syndrome (PEXS) and glaucoma (PEXG) are assumed to be caused by a generalized elastosis leading to the accumulation of PEX material in ocular as well as in extraocular tissues. The exact pathophysiology of PEXS is still elusive. PEXG, the most common type of secondary open-angle glaucoma (OAG), is characterized by large peaks of intraocular pressure (IOP) with a progressive loss of the visual field. Agonistic autoantibodies (agAAbs) against the β₂-adrenergic receptor (AR) have been shown to be present in sera of patients with primary and secondary OAG and ocular hypertension and are seemingly linked to IOP. In the present study, we investigated the autoantibodies directed against the β₂-AR in sera of patients with PEXS and PEXG. We recruited 15, 10, and 15 patients with PEXG, PEXS, and primary OAG, respectively. Ten healthy individuals served as controls. All patients underwent standard ophthalmological examination with Octopus G1 perimetry. agAAbs prepared from serum samples were analyzed in a rat cardiomyocyte-based bioassay for the presence of agAAbs. We identified the interacting loop of the β₂-AR and the immunoglobulin G (IgG) subclasses using synthetic peptides corresponding to the extracellular loops of the receptors and enzyme-linked immunosorbent assay, respectively. None of the controls were β₂-agAAb-positive (0.2 ± 0.5 U). No β₂-agAAbs (0.2 ± 0.4 U), but inhibitory β₂-AAbs were observed in 80% of the patients that partially blocked the drug-induced β₂-adrenergic stimulation; 5.8 ± 1.7 U vs. 11.1 ± 0.9 U for clenbuterol in the absence and the presence of sera from patients with PEXS, respectively. Epitope analyses identified the third extracellular loop of the β₂-AR as the target of the inhibitory β₂-AAbs, being of IgG3 subtype in PEXS patients. In contrast, patients with PEXG showed β₂-agAAbs (5.6 ± 0.9 U), but no inhibitory ones. The β₂-agAAbs levels of patients with PEXG and primary OAG patients (3.9 ± 2.8 U; p > 0.05) were at a similar level. In two cases of PEXG, the β₂-agAAbs exert synergistic effects with clenbuterol. The activity increased from 11.5 ± 0.3 (clenbuterol only) to 16.3 ± 0.9 U. As autoimmune mechanisms were reportedly involved in the pathogenesis of glaucoma, agonistic and inhibitory β₂-AAbs seem to be a part of this multifactorial interplay.

Investigation of Possible Role of Chlamydia in Pseudoexfoliation Syndrome

Background: Pseudoexfoliation syndrome (PES) is a systemic disease characterized by the aggregation of fibrillar extracellular material in intraocular and extraocular tissues with unknown etiology. Clarifying the etiopathogenesis of PES would be important for public health. Objectives: We aimed to investigate the possible role of Chlamydia in the etiology of PES. Methods: This cross-sectional study was carried out in the ophthalmology clinic of a tertiary hospital. The study included two groups, including the patient group (PES patients with nuclear cataracts) and the control group (patients with nuclear cataracts). Patients with other ophthalmic problems and systemic diseases were excluded. Blood samples and conjunctival swabs taken from 49 patients and 42 controls were used in the study. Anti-Chlamydia trachomatis IgG and IgM, anti-C. pneumoniae IgG and IgM, Interleukin (IL)-6, and IL-20 were studied in the serum samples. The PCR study was performed with conjunctival swab samples and sequence analysis of PCR-positive samples was performed. Results: According to the results of the study, there was no statistically significant difference between the groups in terms of anti-C. trachmatis IgG, anti-C. trachmatis IgM, anti-C. pneumoniae IgM, IL-6, and PCR results. There was a statistically significant difference between patient and control groups in terms of anti-C. pneumoniae IgG and IL-20 levels. The DNA sequencing of all PCR products was found to be compatible with C. pneumoniae. Conclusions: It seems that C. pneumoniae might have an important role in the etiology and development of PES. However, further studies in larger groups are needed to clarify these results.

Differential Lysyl oxidase like 1 expression in pseudoexfoliation glaucoma is orchestrated via DNA methylation

Pseudoexfoliation syndrome (PXF) is the most common cause of secondary open angle glaucoma worldwide. Single nucleotide polymorphisms (SNPs) in the gene Lysyl oxidase like 1 (LOXL1) are strongly associated with the development of pseudoexfoliation glaucoma (PXFG). However, these SNPs are also present in 50-80% of the general population, suggestive of other factors being involved in the pathogenesis of PXFG. In this study, we aimed to investigate the influence of epigenetic regulation, specifically DNA methylation, on LOXL1 expression in PXFG using human tenons fibroblasts (HTFs), aqueous humour and serum samples from donors with and without PXFG. LOXL1 expression in HTFs was measured by qPCR and Western Blotting and LOXL1 concentration in aqueous humour was determined by ELISA. Global DNA methylation levels were quantified using an ELISA for 5-methylcytosine. MeDIP assays assessed the methylation status of the LOXL1 promoter region. Expression of methylation-associated enzymes (DNMT1, DNMT3a and MeCP2) were determined by qPCR and inhibited by 0.3 μM 5-azacytidine (5-aza). Results showed that LOXL1 expression was significantly decreased in PXFG HTFs compared with Control HTFs at gene (Fold change 0.37 ± 0.05, P < 0.01) level and showed a decrease, when measured at the protein level (Fold change 0.65 ± 0.42, P = 0.22), however this was not found to be significant. LOXL1 concentration was increased in the aqueous of PXFG patients compared with Controls (2.76 ± 0.78 vs. 1.79 ± 0.33 ng/ml, P < 0.01). Increased global methylation (56.07% ± 4.87% vs. 32.39% ± 4.29%, P < 0.01) was observed in PXFG HTFs compared with Control HTFs, as was expression of methylation-associated enzymes (DNMT1 1.58 ± 0.30, P < 0.05, DNMT3a 1.89 ± 0.24, P < 0.05, MeCP2 1.63 ± 0.30, P < 0.01). Methylation-associated enzymes were also increased when measured at protein level (DNMT1 5.70 ± 2.64, P = 0.04, DNMT3a 1.79 ± 1.55, P = 0.42, MeCP2 1.64 ± 1.33, P = 0.45). LOXL1 promoter methylation was increased in patients with PXFG compared to Control patients in both blood (3.98 ± 2.24, 2.10 ± 1.29, P < 0.05) and HTF cells (37.31 ± 22.0, 8.66 ± 10.40, P < 0.01). Treatment of PXFG HTFs with in 5-azacytidine increased LOXL1 expression when compared with untreated PXFG HTFs (Fold change 2.26 ± 0.67, P < 0.05). These data demonstrate that LOXL1 expression is altered in PXFG via DNA methylation and that reversal of these epigenetic changes may represent future potential therapeutic targets in the management of PXFG.

Peripapillary and macular choroidal vascularity index in patients with clinically unilateral pseudoexfoliation syndrome

PURPOSE

To investigate choroidal vascular changes using an image binarization tool in patients with clinically unilateral pseudoexfoliation syndrome (XFS).

METHODS

This cross-sectional study included 150 eyes of 100 patients. The eyes were divided into three groups: (1) 50 affected eyes of patients with clinically unilateral XFS; (2) 50 unaffected fellow eyes; and (3) 50 healthy control eyes. Enhanced depth imaging optical coherence tomography scans of the macula and peripapillary regions were acquired. Images were binarized using ImageJ software (National Institutes of Health, Bethesda, MD, USA). The choroidal vascularity index (CVI) was defined as proportion of the luminal area to the total circumscribed choroidal area.

RESULTS

Horizontal and vertical scans revealed that the macular CVI values of the affected eyes (60.08 ± 2.06 and 62.21 ± 2.10, respectively) were lower compared with control eyes (67.31 ± 2.24; p = 0.001 and 68.11 ± 2.36; p < 0.001, respectively). Conversely, no significant difference in the macular CVI was found between unaffected fellow and control eyes (p = 0.094 and p = 0.120, respectively). The mean peripapillary CVI values of the temporal (58.73 ± 3.15), superior (59.84 ± 3.09), and inferior (56.94 ± 2.47) sectors were significantly lower in affected eyes compared to control eyes (63.21 ± 3.00, 62.07 ± 3.05, and 60.78 ± 2.88, respectively; p < 0.05 for all). In addition, the unaffected fellow eyes had significantly lower CVI values in the temporal (61.42 ± 3.07) and inferior (57.61 ± 2.56) peripapillary sectors compared with the control eyes (p = 0.007 and p = 0.005, respectively).

CONCLUSIONS

These findings suggest that XFS is associated with decreased macular and peripapillary choroidal vascularity. Furthermore, the unaffected eyes of patients with unilateral XFS may show vascularity changes in the peripapillary choroid.

Lysyl Oxidase Like 1: Biological roles and regulation

Lysyl Oxidase Like 1 (LOXL1) is a gene that encodes for the LOXL1 enzyme. This enzyme is required for elastin biogenesis and collagen cross-linking, polymerising tropoelastin monomers into elastin polymers. Its main role is in elastin homeostasis and matrix remodelling during injury, fibrosis and cancer development. Because of its vast range of biological functions, abnormalities in LOXL1 underlie many disease processes. Decreased LOXL1 expression is observed in disorders of elastin such as Cutis Laxa and increased expression is reported in fibrotic disease such as Idiopathic Pulmonary Fibrosis. LOXL1 is also downregulated in the lamina cribrosa in pseudoexfoliation glaucoma and genetic variants in the LOXL1 gene have been linked with an increased risk of developing pseudoexfoliation glaucoma and pseudoexfoliation syndrome. However the two major risk alleles are reversed in certain ethnic groups and are present in a large proportion of the normal population, implying complex genetic and environmental regulation is involved in disease pathogenesis. It also appears that the non-coding variants in intron 1 of LOXL1 may be involved in the regulation of LOXL1 expression. Gene alteration may occur via a number of epigenetic and post translational mechanisms such as DNA methylation, long non-coding RNAs and microRNAs. These may represent future therapeutic targets for disease. Environmental factors such as hypoxia, oxidative stress and ultraviolet radiation exposure alter LOXL1 expression, and it is likely a combination of these genetic and environmental factors that influence disease development and progression. In this review, we discuss LOXL1 properties, biological roles and regulation in detail with a focus on pseudoexfoliation syndrome and glaucoma.

Pseudoexfoliation syndrome: analysis of systemic comorbidities of 325 PEX-positive patients compared with 911 PEX-negative patients

PURPOSE

Pseudoexfoliation syndrome (PEX) is an age-related systemic elastic fibrillopathy disorder featuring an excessive production and accumulation of elastic fibre components in the extracellular matrix and is associated with impaired protective mechanisms against oxidative and cellular stress. PEX is diagnosed solely by ophthalmologists; however, PEX deposits have been detected in the connective tissues of many extraocular organ systems. This large, retrospective case-control study investigates whether patients with PEX have an increased risk of extraocular comorbidities.

METHODS

Cases and controls were drawn from consecutive patients over 50 years of age undergoing in-house ophthalmological operations under general anaesthesia or in standby preparedness for general anaesthesia. The participants were grouped based solely on PEX-positive (n = 325) or PEX-negative (n = 911) status. The same teams of ophthalmologists and anaesthesiologists uniformly documented every known systemic comorbidity of each patient through two independent rounds of standard anamnestic procedure and protocols in preparation for general anaesthesia. For the purpose of this study, every systemic comorbidity was registered from these forms and subsequently categorized into 17 disease groups based on the International Classification of Diseases (ICD-10) of the World Health Organization (WHO). Odds ratios (ORs) comparing comorbidities in cases and controls were adjusted for age and gender using logistic regression.

RESULTS

After adjustment for multiple testing, patients with PEX had an increased odds ratio for respiratory OR 2.1 [1.4; 3.0], cardiac OR 2.5 [1.6; 4.2], vascular OR 2.0 [1.4; 2.8], and urogenital conditions OR 2.3 [1.4; 3.7]. Renal and psychiatric comorbidities were nominally significant. While no substantially higher frequency was found for hernias, aneurysms, aortic dissection, or varicose veins among PEX-positive patients, higher rates of cardiac valve disorders and benign prostate hyperplasia were found among the PEX-positive individuals.

CONCLUSION

In addition to confirming an increased risk of respiratory, cardiovascular, and urogenital comorbidities, our data found an increased risk of cardiac valve disorders and benign prostate hyperplasia among PEX-positive patients, which may be manifestations of the underlying systemic elastotic fibrillopathy and warrants further exploration, including future histological study.

De novo variants in an extracellular matrix protein coding gene, fibulin-5 (FBLN5) are associated with pseudoexfoliation

Fibulin-5 (FBLN5), an extracellular scaffold protein, plays a crucial role in the activation of Lysyl oxidase like-1 (LOXL1), a tropoelastin crosslinking enzyme, and subsequent deposition of elastin in the extracellular matrix. Following study identifies polymorphisms within FBLN5 gene as risk factors and its aberrant expression in the pathogenesis of an ocular disorder, pseudoexfoliation (PEX). Exons and exon-intron boundaries within FBLN5 gene were scanned through fluorescence-based capillary electrophoresis for polymorphisms as risk factors for PEX pathogenesis in recruited study subjects with Indian ethnicity. mRNA and protein expression of FBLN5 was checked in lens capsule of study subjects through qRT-PCR and western blotting, respectively. In vitro functional analysis of risk variants was done through luciferase reporter assays. Thirty study subjects from control and PEX affected groups were scanned for potential risk variants. Putative polymorphisms identified by scanning were further evaluated for genetic association in a larger sample size comprising of 338 control and 375 PEX affected subjects. Two noncoding polymorphisms, hg38 chr14:g.91947643G>A (rs7149187:G>A) and hg38 chr14:g.91870431T>C (rs929608:T>C) within FBLN5 gene are found to be significantly associated with PEX as risk factors with a p-value of 0.005 and 0.004, respectively. Molecular assays showed a decreased expression of FBLN5 at both mRNA and protein level in lens capsule of pseudoexfoliation syndrome (PEXS) affected subjects than control. This study unravels two novel risk variants within FBLN5 gene in the pathogenesis of PEX. Further, a decreased expression of FBLN5 in PEXS affected lens capsules implicates a pathogenic link between extracellular matrix maintenance and onset of PEX.

Macula Vessel Density and Foveal Avascular Zone Parameters in Exfoliation Glaucoma Compared to Primary Open-Angle Glaucoma

Purpose

The purpose of this study was to explore macula vessel density and foveal avascular zone (FAZ) parameters in exfoliation glaucoma (XFG) compared to primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA).

Methods

This was a cross-sectional observational study. Twenty-six XFG and 28 POAG patients with comparable visual field defects on Humphrey 24-2 and 10-2 perimetries were recruited. OCTA scans (3 × 3 mm) centered on the fovea were obtained. Built-in software was used to measure superficial capillary plexus (SCP) vessel density at different quadrants of the macula. Custom software was then used to create a full-thickness image. The FAZ was manually delineated, and large vessels were removed. Vessel density in eight concentric rings with increments of 200-μm diameters from the delineated FAZ was measured. FAZ parameters were calculated using the custom software.

Results

SCP density was significantly lower in the superior (mean difference [MD] = -4.32, 95% confidence interval [CI] = -7.02, -1.61, P = 0.003) and nasal (MD = -3.00, 95% CI = 05.22, -0.77, P = 0.010) quadrants in XFG versus POAG. SCP vessel density using the concentric ring approach revealed significantly decreased values at all eight rings in XFG versus POAG. In the full-thickness analysis, density was significantly less in the XFG group in all rings except the initial 200 μm. No significant differences existed in FAZ parameters between the groups.

Conclusions

Despite the presence of comparable central visual field defects, the macula vessel density was predominately lower in XFG compared with POAG in our sample of patients. Further studies are warranted to investigate the consistency of our results.

YKL-40 is a local marker for inflammation in patients with pseudoexfoliation syndrome

PURPOSE

To investigate the YKL-40, as a marker of inflammation, in aqueous humor and serum of cataract patients with and without pseudoexfoliation syndrome (PEX).

METHODS

Aqueous humor and serum samples were obtained from 44 patients who underwent phacoemulsification surgery. All patients were divided into two groups: PEX (n = 24) and control (n = 20). YKL-40 levels were measured with enzyme-linked immunosorbent assay (ELISA). The differences between the groups were assessed by using Chi-square and independent sample t-tests. The Pearson correlation coefficient was used to evaluate the correlation between variables.

RESULTS

There was a significant difference between the mean YKL-40 levels in the aqueous humor of PEX group (112.0 ± 35.8 ng/mL) and control subjects (88.2 ± 30.6 ng/mL) (P = 0.025). However, the difference between the mean YKL-40 levels in the serum of PEX group (53.5 ± 29.1 ng/mL) and control subjects (44.6 ± 30.2 ng/mL) was non-significant (P = 0.326). The correlation between aqueous humor and serum YKL-40 concentrations was significant in both the groups (r = 0.833, P < 0.001; r = 0.840, P < 0.001, respectively).

CONCLUSIONS

Increased aqueous humor levels of YKL-40 demonstrate that it is local, but not a systemic marker for inflammation in patients with PEX.

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.

Carotid Arterial Flow in Pseudoexfoliation Glaucoma and its Role in Diagnosing the Disease

OBJECTIVE OF THE STUDY

The objective of the study was to investigate the change in carotid arterial flow in pseudoexfoliation glaucoma (XFG) for determining its diagnostic value.

MATERIALS AND METHODS

Patients with XFG (N=30) and control subjects (N=22) were recruited. Common carotid artery (CCA) and internal carotid artery of each participant were examined using color Doppler and B-mode ultrasonography. Resistivity index (RI), as a flow parameter of interest, was measured and statistically compared between the 2 groups. Receiver operating characteristic was also produced to assess its diagnostic value.

RESULTS

The measured RI values from the controls were within the expected range. Among CCA and internal carotid artery, only RI of CCA exhibited statistically significant changes in XFG (0.75±0.04 vs. 0.70±0.03 cm/s). Threshold value of RI=0.72 yielded 90% sensitivity and 73% specificity in distinguishing the cases of XFG from the controls.

CONCLUSIONS

Flow dynamics of carotid arterial system exhibits different characteristics in individuals with XFG than controls. Such differences may serve as a basis for developing potentially new diagnostic biomarkers of XFG. Further studies are justified for examining the carotid flow in pseudoexfoliation syndrome and compare it against XFG for determining its power in differential diagnosis.

Ocular Pseudoexfoliation Syndrome Linkage to Cardiovascular Disease

PURPOSE OF REVIEW

Pseudoexfoliation syndrome (PEX) is a common cause of open-angle glaucoma that is characterized by stress-induced elastic microfibrillopathy related to an accumulation of matrix metalloproteinases. The accumulation of matrix metalloproteinases increases deposition of protein substance within ocular structures and other organs including the heart. Many studies have associated the presence of cardiovascular disease with pseudoexfoliation syndrome, but much debate exists between studies in terms of significant relationships. The following meta-analysis aims to relate pseudoexfoliation syndrome with certain cardiovascular events and disorders. A thorough literature review was performed to acquire information concerning PEX patients with certain cardiovascular disorders. Diseases considered included myocardial infarction, ischemic heart disease, angina, congestive heart failure, cardiomyopathy, aortic aneurysm, hypertension, and homocystinuria. Patients without evidence of pseudoexfoliation disease were the controls of our study. Multiple forest plots were created to compile and analyze collected data for statistical comparison.

RECENT FINDINGS

From a literature review, 18 studies were selected for our analysis. Cardiovascular disorders that had a statistically significant association (within a 95 % confidence interval) with PEX included ischemic heart disease, aortic aneurysms, and homocystinuria. The association between ischemic heart disease and PEX was statistically significant (p = 0.045). Myocardial infarction, chronic ischemic heart disease, angina, and hypertension did not show a correlation of relationship with the presence of pseudoexfoliation. Patients with PEX are prone to present with ischemic heart disease in addition to abdominal aortic aneurysms and homocystinuria. Patients that present with PEX should be screened for these detrimental cardiovascular disorders.

Pseudoexfoliation syndrome-associated genetic variants affect transcription factor binding and alternative splicing of LOXL1

Although lysyl oxidase-like 1 (LOXL1) is known as the principal genetic risk factor for pseudoexfoliation (PEX) syndrome, a major cause of glaucoma and cardiovascular complications, no functional variants have been identified to date. Here, we conduct a genome-wide association scan on 771 German PEX patients and 1,350 controls, followed by independent testing of associated variants in Italian and Japanese data sets. We focus on a 3.5-kb four-component polymorphic locus positioned spanning introns 1 and 2 of LOXL1 with enhancer-like chromatin features. We find that the rs11638944:C>G transversion exerts a cis-acting effect on the expression levels of LOXL1, mediated by differential binding of the transcription factor RXRα (retinoid X receptor alpha) and by modulating alternative splicing of LOXL1, eventually leading to reduced levels of LOXL1 mRNA in cells and tissues of risk allele carriers. These findings uncover a functional mechanism by which common noncoding variants influence LOXL1 expression.

LOXL1 is a genetic risk factor for pseudoexfoliation syndrome of the eye but a causal variant has not been identified. Here, Pasutto et al., find intronic LOXL1 risk variants influence transcription factor binding and alternative splicing of LOXL1 in affected tissues reducing levels of LOXL1 mRNA.

Major review: Exfoliation syndrome; advances in disease genetics, molecular biology, and epidemiology

Exfoliation syndrome (XFS) is a common age-related disorder that leads to deposition of extracellular fibrillar material throughout the body. The most recognized disease manifestation is exfoliation glaucoma (XFG), which is a common cause of blindness worldwide. Recent developments in XFS genetics, cell biology and epidemiology have greatly improved our understanding of the etiology of this complex inherited disease. This review summarizes current knowledge of XFS pathogenesis, identifies gaps in knowledge, and discusses areas for future research.

Exfoliation syndrome: assembling the puzzle pieces

PURPOSE

To summarize various topics and the cutting edge approaches to refine XFS pathogenesis that were discussed at the 21st annual Glaucoma Foundation Think Tank meeting in New York City, Sept. 19-20, 2014.

METHODS

The highlights of three categories of talks on cutting edge research in the field were summarized.

RESULTS

Exfoliation syndrome (XFS) is a systemic disorder with a substantial ocular burden, including high rates of cataract, cataract surgery complications, glaucoma and retinal vein occlusion. New information about XFS is akin to puzzle pieces that do not quite join together to reveal a clear picture regarding how exfoliation material (XFM) forms.

CONCLUSION

Meeting participants concluded that it is unclear how the mild homocysteinemia seen in XFS might contribute to the disarrayed extracellular aggregates characteristic of this syndrome. Lysyl oxidase-like 1 (LOXL1) variants are unequivocally genetic risk factors for XFS but exactly how these variants contribute to the assembly of exfoliation material (XFM) remains unclear. Variants in a new genomic region, CACNA1A associated with XFS, may alter calcium concentrations at the cell surface and facilitate XFM formation but much more work is needed before we can place this new finding in proper context. It is hoped that various animal model and ex vivo systems will emerge that will allow for proper assembly of the puzzle pieces into a coherent picture of XFS pathogenesis. A clear understanding of XFS pathogenesis may lead to 'upstream solutions' to reduce the ocular morbidity produced by XFS.

Systemic Associations of Exfoliation Syndrome

Exfoliation syndrome (XFS) is an age-related disease characterized by the production, deposition, and progressive accumulation of a white, fibrillar, extracellular material in many ocular tissues, most prominent on the anterior lens surface and pupillary border. Its prevalence increases steadily with age in all populations. It is the most common identifiable cause of open-angle glaucoma worldwide and is a potentially reversible or even curable disease. First described in Finland in 1917 by Lindberg, it has long been associated with open-angle glaucoma. However, in recent years, it is being increasingly reported in conjunction with a multiplicity of both ocular and systemic disorders, and the number of these is expected to grow, particularly with investigations based on attempts to associate other diseases with those genes known to be associated with XFS. Despite the focus on XFS as a cause of open-angle glaucoma for nearly a century, in reality it is still only an ocular manifestation of a protean systemic disease. It is a unique disorder with extensive and often serious ocular and systemic manifestations and not, as it has long been termed, a "form" or "type" of glaucoma. This misconception has delayed research into the molecular and cellular processes involved in its development, and the underestimation of its overall importance and its underlying causative mechanisms have largely been long ignored. The purpose of this article is to review the systemic disorders which are becoming increasingly associated with XFS. Reviews of epidemiology, genetics, biomarkers, molecular mechanisms of development, and ocular findings may be found elsewhere.

Plateletcrit in Ocular Pseudoexfoliation Syndrome

PURPOSE

The aim of this study was to compare all platelet markers, especially plateletcrit (PCT, total platelet mass), in patients with and without ocular pseudoexfoliation (PEX) syndrome.

METHODS

One hundred six patients with ocular PEX syndrome (study group) and 106 individuals without ocular PEX syndrome (control group) were enrolled in this retrospective case-control study. The biochemical/hematological laboratory results of both the study and control groups were analyzed by a clinician blinded to the group assignments. The main outcome measures were the PCT, platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW).

RESULTS

The mean PCT in the study and control groups were 0.206%±0.520% and 0.171%±0.410%, respectively (P<0.001), and the mean PDW in the study and control groups were 16.12%±1.21% and 14.68%±1.40%, respectively (P<0.001). There were no differences in the MPV or mean PLT (P=0.138 and P=0.055, respectively). The PCT cutoff value was 0.180 (area under the receiver operating characteristics curve, 0.706; P<0.001; 65% sensitivity; 74% specificity).

CONCLUSIONS

The PCT and PDW were significantly higher in patients with than without ocular PEX syndrome. These increased parameters may cause microvascular blood flow resistance and the heightened inflammatory response caused by excessive platelet activity, as with other cardiovascular diseases, and may also decrease aqueous humor outflow in ocular PEX syndrome.

Serum Uric Acid, Alanine Aminotransferase, Hemoglobin and Red Blood Cell Count Levels in Pseudoexfoliation Syndrome

Purpose. The pathogenesis of pseudoexfoliation (PEX), the most common cause of secondary glaucoma, has not been clearly identified, but there is increasing evidence that points out the role of oxidative stress. The aim of this study is to evaluate some of the most commonly used blood parameters, hemoglobin (Hb), red blood cell count (RBC), alanine aminotransferase (ALT), and uric acid (UA) levels, in subjects with PEX. Materials and Methods. This study is performed in a state hospital between November 2011 and December 2012. Retrospective chart review of subjects who underwent cataract surgery was performed. Thirty-one healthy subjects with PEX and 34 healthy subjects without PEX were evaluated. Hb, RBC, ALT, and UA levels were recorded. Student's t-test was used to compare the two groups. Results. The mean age was 73.6 ± 14.1 years in PEX group and 70.1 ± 12.7 in control group (p = 0.293). Hb, RBC, ALT, and UA levels did not show a statistically significant difference among PEX and control groups (p > 0.05 for all). Conclusion. Serum levels of Hb, RBC, ALT, and UA levels were similar in subjects with and without PEX. Further studies are needed to clarify the precise role of Hb, RBC, ALT, and UA in the pathogenesis of PEX.

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.

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

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

Update on pseudoexfoliation syndrome pathogenesis and associations with intraocular pressure, glaucoma and systemic diseases

PURPOSE OF REVIEW

Pseudoexfoliation (PEX) syndrome is a common age-related disorder affecting intraocular and extraocular tissues. This review focuses on recent publications related with the pathogenesis and associations of PEX syndrome with intraocular pressure (IOP), glaucoma and systemic diseases.

RECENT FINDINGS

In PEX tissues, expression of lysyl oxidase-like 1 (LOXL1) was found to be markedly dysregulated. This may adversely affect elastin metabolism and lead to elastotic alteration in tissues such as lamina cribrosa. There is increasing evidence that cellular stress conditions and low-grade chronic inflammatory processes are involved in the pathogenesis of PEX. Although there is an increased risk for glaucoma development in patients with PEX and ocular hypertension as compared with non-PEX patients with ocular hypertension, LOXL1 single nucleotide polymorphisms were not associated with intraocular pressure (IOP) differences. Lack of association of PEX with all-cause mortality or dementia has been reported recently. The association with vascular diseases is not consistent among different studies.

SUMMARY

Despite the high prevalence of the LOXL1 variants in the general population, a much lower proportion of the population develops PEX, suggesting that in addition to LOXL1, other genetic, epigenetic and environmental factors may contribute to the development of PEX. Also, LOXL1 cannot help to identify those with PEX at increased risk for glaucoma development. Increased risk for glaucoma development in PEX patients who present with increased IOP may be related to other factors beyond IOP, contributing to increased vulnerability of the optic nerve to glaucoma development in the presence of PEX.

Pseudoexfoliation syndrome and cardiovascular diseases

Pseudoexfoliation (PEX) syndrome is a well-recognized late-onset disease caused by a generalized fibrillopathy. It is linked to a broad spectrum of ocular complications including glaucoma and perioperative problems during cataract surgery. Apart from the long-known intraocular manifestations, PEX deposits have been found in a variety of extraocular locations and they appear to represent a systemic process associated with increased cardiovascular and cerebrovascular morbidity. However, as published results are inconsistent, the clinical significance of the extraocular PEX deposits remains controversial. Identification of PEX deposits in the heart and the vessel wall, epidemiologic studies, as well as, similarities in pathogenetic mechanisms have led to the hypothesis of a possible relation between fibrillar material and cardiovascular disease. Recent studies suggest that PEX syndrome is frequently linked to impaired heart and blood vessels function. Systemic and ocular blood flow changes, altered parasympathetic vascular control and baroreflex sensitivity, increased vascular resistance and decreased blood flow velocity, arterial endothelial dysfunction, high levels of plasma homocysteine and arterial hypertension have all been demonstrated in PEX subjects. Common features in the pathogenesis of both atherosclerosis and PEX, like oxidative stress and inflammation and a possible higher frequency of abdominal aorta aneurysm in PEX patients, could imply that these grey-white deposits and cardiovascular disorders are related or reflect different manifestations of the same process.

Cardiovascular repercussions of the pseudoexfoliation syndrome

Pseudoexfoliation syndrome is a primarily ophthalmological disorder caused by deposition of whitish-gray protein on the lens, iris, and multiple other eye tissues. There is increasing evidence over the previous years that pseudoexfoliation syndrome is a systemic disorder with various extraocular manifestations and has recently been linked to several cardiovascular disorders. The present article aims to summarize the current knowledge on cardiovascular implications of this well-described clinical entity.

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.