Association of pseudoexfoliation syndrome with cardiovascular and cerebrovascular disease: a systematic review and meta-analysis

Association of Open-Angle Glaucoma With Dementia in California Medicare Beneficiaries

PURPOSE

To examine the associations between open-angle glaucoma (OAG) subtypes and dementia in 2019 California Medicare beneficiaries.

DESIGN

Retrospective cross-sectional study.

METHODS

OAG diagnosis was determined by the International Classification of Diseases, Tenth Revision (ICD-10), diagnosis codes in part B claims, including the following OAG subtypes: primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), and pigmentary glaucoma (PG). Diagnoses of any dementia, Alzheimer dementia (AD), frontotemporal dementia (FTD), Lewy body dementia (LBD), and vascular dementia (VD) were identified by ICD-10 diagnosis codes. Covariates included demographics, systemic diseases, depression, hearing loss, obesity, smoking and alcohol-related disorders, and long-term aspirin, anticoagulant, and antithrombotic or antiplatelet use. Univariate and multivariable logistic regression models were used to assess the associations between OAG and dementia, adjusting for all covariates. Age-stratified analysis was also performed for beneficiaries aged 65-74 years, 75-84 years, and ≥85 years.

RESULTS

Among the 2,431,150 California Medicare beneficiaries included in this study, 104,873 (4.3%) had POAG, 9199 (0.4%) had NTG, 4045 (0.2%) had PXG, and 1267 (0.05%) had PG. The overall prevalence of any dementia was 3.2% (n = 79,009). In adjusted analyses, the odds of any dementia were lower for beneficiaries with all OAG subtypes compared with beneficiaries without glaucoma (odds ratio [OR] = 0.74 for POAG, OR = 0.74 for PXG, OR = 0.60 for NTG, and OR = 0.38 for PG; P < .01). In age-stratified analyses, beneficiaries with PXG had greater odds of VD (OR 2.84, P = .006; aOR 2.18, P = .04) in the youngest age stratum (65-74 years) compared to patients with no glaucoma. The odds for any dementia were lower for beneficiaries with all OAG subtypes compared to beneficiaries without glaucoma in the oldest, but not in the youngest, age stratum.

CONCLUSIONS

In the 2019 California Medicare population, PXG is associated with an increased likelihood of VD in beneficiaries 65-74 years old, whereas other subtypes of POAG are associated with a decreased likelihood of any dementia. These findings may suggest selection bias because older adults who continue to follow up with glaucoma care may be more cognitively intact. Further studies are needed to better understand the complex relationship between glaucoma, dementia, and their subtypes.

Subfoveal choroidal thickness changes in patients with pseudoexfoliation syndrome (PEX) compared to healthy controls: A systematic review and meta-analysis

PURPOSE

To investigate changes in choroidal thickness in patients diagnosed with pseudoexfoliation syndrome (PEX) compared to healthy controls, using optical coherence tomography (OCT).

METHODS

PubMed and Scopus databases were systematically searched for published articles comparing choroidal thickness between patients with PEX and healthy controls. Standardized Mean Difference (SMD) with 95 % confidence interval (CI) was computed to compare continuous variables. Revman 5.4 was used for the analysis. Subgroup analyses were performed according to OCT devices used.

RESULTS

12 studies were included in our analysis. Subfoveal choroidal thickness was decreased in patients with PEX compared to healthy controls. Subgroup analysis confirmed this finding in studies that used Heidelberg or Optovue OCT Devices.

CONCLUSION

Our meta-analysis showed that choroidal thickness was decreased in patients with PEX compared to controls. Increased heterogeneity and small case-control studies are the main limitations of the meta-analysis. Further studies are needed to evaluate the clinical significance of reduced subfoveal choroidal thickness in PEX.

Pseudoexfoliation Syndrome Presenting With Bilateral Visual Impairment and Intraocular Pressure Discrepancy: A Case Report

Pseudoexfoliation syndrome (PEX) presents a significant clinical challenge due to its diverse ocular manifestations, including glaucoma and zonular weakness of the lens, which can lead to irreversible visual impairment if left untreated. We report a case of a 78-year-old male presenting with bilateral visual impairment persisting for four years, with a more pronounced decline in the right eye over the past six months. Examination revealed aphakia with pseudoexfoliative material in the right eye, a cataract with pseudoexfoliative material in the left eye, and a notable intraocular pressure (IOP) discrepancy. Surgical intervention was required for both eyes, with cataract extraction and IOP-lowering procedures performed to preserve vision and prevent further deterioration. This case underscores the importance of timely recognition and comprehensive management of PEX-related ocular complications to optimize visual outcomes and quality of life for affected individuals. Close collaboration between ophthalmologists and other healthcare professionals is essential to address the multifaceted nature of PEX and tailoring treatment strategies to individual patient needs. Further research is needed to elucidate the underlying pathophysiology of PEX and refine therapeutic approaches to mitigate its detrimental effects on vision.

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.

Optic nerve head vessel density in patients with pseudoexfoliation syndrome/glaucoma: a systematic review and meta-analysis

PURPOSE

Exfoliative material has been shown to accumulate in ocular and systemic tissues. We aimed to perform a systematic review and meta-analysis of the current literature evaluating optic nerve head vessel density (VD) using optical coherence tomography angiography (OCTA) in patients with XFS and XFG.

METHODS

Studies were retrieved from PubMed, Scopus, and Web of Science databases. Studies comparing patients with XFS and/or XFG patients to healthy controls, using the optic nerve head-centred 4.5 × 4.5 mm square OCTA scan protocol were included. Pooled results are presented as standardised mean differences with 95% confidence intervals (CI). Meta-regression analysis was performed between mean difference in circumpapillary VD between XFG and controls and mean pRNFL thickness in patients with XFG.

RESULTS

Fifteen studies with 1475 eyes were included in this review. Whole image VD and circumpapillary VD (cpVD) were significantly decreased in patients with XFS [-0.78(95% Cl: -1.08, -0.47); [-0.55(95% Cl: -0.80, -0.30); respectively] and XFG [-1.85(95% CI: -2.33, -1.36); -1.84 (95% CI: -2.30, -1.39); respectively] compared to healthy controls. Furthermore, pRNFL thickness decreased in patients with XFS [-0.55(95% Cl: -0.72, -0.35)] and XFG [-1.78(95% Cl: -2.21, -1.36)] compared to healthy controls. Meta-regression showed that pRNFL thickness decreased with increasing mean cpVD difference in XFG patients compared to healthy controls.

CONCLUSIONS

OCTA provides non-invasive, objective and reproducible assessment of peripapillary VD and is important for the detection of vasculopathy in patients with XFS or XFG. This study provides strong evidence for decreased cpVD in the eyes of patients with XFS and XFG.

Analysis of genetically determined gene expression suggests role of inflammatory processes in exfoliation syndrome

BACKGROUND

Exfoliation syndrome (XFS) is an age-related systemic disorder characterized by excessive production and progressive accumulation of abnormal extracellular material, with pathognomonic ocular manifestations. It is the most common cause of secondary glaucoma, resulting in widespread global blindness. The largest global meta-analysis of XFS in 123,457 multi-ethnic individuals from 24 countries identified seven loci with the strongest association signal in chr15q22-25 region near LOXL1. Expression analysis have so far correlated coding and a few non-coding variants in the region with LOXL1 expression levels, but functional effects of these variants is unclear. We hypothesize that analysis of the contribution of the genetically determined component of gene expression to XFS risk can provide a powerful method to elucidate potential roles of additional genes and clarify biology that underlie XFS.

RESULTS

Transcriptomic Wide Association Studies (TWAS) using PrediXcan models trained in 48 GTEx tissues leveraging on results from the multi-ethnic and European ancestry GWAS were performed. To eliminate the possibility of false-positive results due to Linkage Disequilibrium (LD) contamination, we i) performed PrediXcan analysis in reduced models removing variants in LD with LOXL1 missense variants associated with XFS, and variants in LOXL1 models in both multiethnic and European ancestry individuals, ii) conducted conditional analysis of the significant signals in European ancestry individuals, and iii) filtered signals based on correlated gene expression, LD and shared eQTLs, iv) conducted expression validation analysis in human iris tissues. We observed twenty-eight genes in chr15q22-25 region that showed statistically significant associations, which were whittled down to ten genes after statistical validations. In experimental analysis, mRNA transcript levels for ARID3B, CD276, LOXL1, NEO1, SCAMP2, and UBL7 were significantly decreased in iris tissues from XFS patients compared to control samples. TWAS genes for XFS were significantly enriched for genes associated with inflammatory conditions. We also observed a higher incidence of XFS comorbidity with inflammatory and connective tissue diseases.

CONCLUSION

Our results implicate a role for connective tissues and inflammation pathways in the etiology of XFS. Targeting the inflammatory pathway may be a potential therapeutic option to reduce progression in XFS.

Systemic immuno-inflammatory index in patients with pseudoexfoliation syndrome and pseudoexfoliative glaucoma

Background

In recent years, the role of some hematological parameters used as chronic inflammation markers in the pathogenesis of many ocular and systemic diseases has been investigated. For ocular diseases such as uveitis, keratoconus, and retinal vein occlusion, the neutrophil/lymphocyte ratio (NLR) and systemic immune-inflammatory index (SII) have been reported to be useful inflammatory biomarkers. It has also been reported that low-grade chronic inflammation plays a role in the formation of pseudoexfoliation.

Objective

To evaluate the NLR, SII, and platelet-lymphocyte ratio (PLR) in patients with pseudoexfoliation syndrome (PEXS) and pseudoexfoliative glaucoma (PEXG).

Design

This was a retrospective case-control study.

Methods

This study evaluated the clinical and laboratory data of 34 patients with PEXS, 33 patients with PEXG, and 33 control patients. Detailed eye examination notes in patient files and blood count measurements were recorded.

Results

SII values were the highest in the PEXS group, followed by the PEXG and control groups (582.01 ± 339.9, 478.14 ± 211.7, and 413.98 ± 129.5, respectively) (p = 0.043). In paired comparisons, the SII values of the PEXS group were significantly higher than the control group (p = 0.011). The mean NLR rate was highest in the PEXS group, followed by the PEXG and the control groups (2.46 ± 1.6, 2.17 ± 0.8, and 1.69 ± 0.4, respectively) (p = 0.023). In paired comparisons, the mean NLR levels were higher in the PEXS and the PEXG groups than in the control group (p = 0.03 and p = 0.01, respectively). There was no significant difference between the groups in terms of PLR. According to receiver operating characteristic curve analysis, the optimal cut-off value for estimating PEXS was found as >449.4 for SII and 1.78 for NLR (p = 0.011 and p = 0.031, respectively).

Conclusions

In PEXS patients, both SII and NLR were significantly higher, albeit in a small group of patients, and SII may be a helpful and supportive parameter for NLR in risk estimation in these patients. There was a statistically significant difference only in NLR in patients with PEXG when compared with the control group. However, these results need to be supported by future longitudinal and larger studies to identify any possible link between hematological inflammatory markers and pseudoexfoliation.

Impact of cardiovascular comorbidity on increased neutrophil-lymphocyte ratio in pseudoexfoliation syndrome

BACKGROUND

The purpose of this study was to compare neutrophil-to-lymphocyte ratios (NLRs) of patients with pseudoexfoliation syndrome (PEX) according to the presence of cardiovascular disease (CVD) with those without CVD as controls.

METHODS

A total of 197 participants (97 patients with PEX and 100 participants without PEX regarded as the control group) were included in this retrospective study. The PEX group was divided into 2 subgroups, PEX with CVD (group 1) and PEX without CVD (group 2). NLRs were then compared to those of the control group.

RESULTS

The incidence of CVD was significantly (P = .015) higher in the PEX group than in the control group. NLR was significantly higher in the group 1 and group 2 compared with that of the control group (P = .048 and P = .002, respectively). In the PEX group, group 1 showed higher NLR than group 2 (P = .023).

CONCLUSION

Although the PEX group showed a higher incidence of CVD, the NLR was higher in the PEX group regardless of cardiovascular comorbidity than that in the control group.

Compositional Analysis of Extracellular Aggregates in the Eyes of Patients With Exfoliation Syndrome and Exfoliation Glaucoma

Purpose

Exfoliation syndrome (XFS) is a condition characterized by the production of insoluble fibrillar aggregates (exfoliation material; XFM) in the eye and elsewhere. Many patients with XFS progress to exfoliation glaucoma (XFG), a significant cause of global blindness. We used quantitative mass spectrometry to analyze the composition of XFM in lens capsule specimens and in aqueous humor (AH) samples from patients with XFS, patients with XFG and unaffected individuals.

Methods

Pieces of lens capsule and samples of AH were obtained with consent from patients undergoing cataract surgery. Tryptic digests of capsule or AH were analyzed by high-performance liquid chromatography–mass spectrometry and relative differences between samples were quantified using the tandem mass tag technique. The distribution of XFM on the capsular surface was visualized by SEM and super-resolution light microscopy.

Results

A small set of proteins was consistently upregulated in capsule samples from patients with XFS and patients with XFG, including microfibril components fibrillin-1, latent transforming growth factor-β–binding protein-2 and latent transforming growth factor-β–binding protein-3. Lysyl oxidase-like 1, a cross-linking enzyme associated with XFS in genetic studies, was an abundant XFM constituent. Ligands of the transforming growth factor-β superfamily were prominent, including LEFTY2, a protein best known for its role in establishing the embryonic body axis. Elevated levels of LEFTY2 were also detected in AH from patients with XFG, a finding confirmed subsequently by ELISA.

Conclusions

This analysis verified the presence of suspected XFM proteins and identified novel components. Quantitative comparisons between patient samples revealed a consistent XFM proteome characterized by strong expression of fibrillin-1, lysyl oxidase-like-1, and LEFTY2. Elevated levels of LEFTY2 in the AH of patients with XFG may serve as a biomarker for the disease.

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.

Exfoliation syndrome: association with systemic diseases-the Maccabi glaucoma study

PURPOSE

To investigate the relationship between exfoliation syndrome (XFS) and systemic diseases.

METHODS

A population-based, retrospective study with control group was conducted using the electronic medical database of Maccabi Health Services, the second largest Health Maintenance Organization (HMO) in Israel. Study population included Maccabi members from January 2003 to April 2016. Cases consisted of patients diagnosed with XFS regardless of glaucoma. The control group included Maccabi members without XFS, matched on age, sex, and ancestry, that were examined by an ophthalmologist within the last year.

MAIN OUTCOME MEASURES

Associations between XFS and systemic diseases.

RESULTS

We identified 16,388 patients with XFS, in whom 40.3% (n = 6613) had glaucoma. The control group included 14,015 patients. Mean age was 78.3 ± 8.9 years and 76.2 ± 8.5 years for the XFS and control group, respectively. In unconditional logistic regression analyses, after adjusting for age, sex, and ancestry, XFS was significantly associated with risk of cardiovascular diseases including hypertension (OR 1.07, 95% CI 1.01-1.13, p = 0.02), myocardial infarction (OR 1.21, 95% CI 1.17-1.31, p < 0.0001), and congestive heart failure (OR 1.70, 95% CI 1.55-1.88, p < 0.0001) as well as higher risk for high creatinine (OR 1.28, 95% CI 1.2-1.37, p < 0.0001). Diabetes mellitus and body mass index were inversely associated with XFS (OR 0.70, 95% CI 0.67-0.73, p < 0.0001 and OR 0.88, 95% CI 0.84-0.93, p < 0.0001, respectively). Overall cancer diagnoses were more common in the XFS group (OR 1.05, 95% CI 1.0-1.1, p = 0.05). XFS was associated with more hospitalizations (mean 5 ± 5.3 hospitalizations in the XFS group and 3.3 ± 4.0 in the controls, p < 0.0001).

CONCLUSION

XFS is significantly associated with cardiovascular systemic diseases (in a population living in Israel and predominantly born in Russia).

A Case-Cohort Study of Exfoliation Risk Factors and Literature Review

The purpose of the study is to evaluate the risk factors associated with exfoliation in a case-cohort setting and literature review. This single-center, prospective, case-cohort study was carried out from January 2010 to April 2020 on patients operated for cataract surgery by a single surgeon in Lebanon. Forty-nine consecutive patients with exfoliation syndrome (XFS) and 62 consecutive control patients were identified and further investigated for selected systemic (diabetes mellitus, systemic hypertension, asthma, or atopy) and ocular variables (baseline vision, severity of nuclear sclerosis, glaucoma, eye rubbing, history of dry eye, or allergic eye disease). The mean baseline Snellen visual acuity was 20/283 in XFS versus 20/145 in control cases (P = 0.012). XFS also demonstrated significantly denser nuclear sclerosis than controls (P = 0.00958). By univariate analysis, allergic conjunctivitis (15 [30.6%] vs. 2 [3.2%]; P < 0.001), dry eye (20 [40.8%] vs. 13 [21.0%]; P = 0.0133), and habitual rubbing of the eyes (33 [67.3%] vs. 19 [30.6%]; P < 0.001) were associated with the presence of XFS. Habitual ocular rubbing was closely associated with allergic conjunctivitis (odds ratio [OR] = 13.0; 95% confidence interval [CI]: 2.8–58.8; P = 0.032). After multivariable analysis, the following variables showed significant results: glaucoma (OR = 34.5; 95% CI: 4.4–250; P = 0.010), duration of surgery (OR = 5.6; 95% CI 2.43–12.9; P < 0.001), and habitual ocular rubbing (OR = 4.42; 95% CI: 1.97–9.90; P = 0.029). This study shows a novel potential correlation between eye rubbing and XFS in a Lebanese cohort. Chronic eye rubbing induces or may exacerbate preexistent zonular damage in subjects with XFS, hence the need to better manage concurrent ocular surface disorder in these patients.

Changes in peri-ocular anatomy and physiology in pseudoexfoliation syndrome (Review)

Pseudoexfoliation syndrome (PEX) is characterized by the deposition of proteinaceous material in the anterior ocular segment (resulting in ophthalmic pathologies such as glaucoma and increased risk of complications in cataract surgery), but also by several systemic manifestations. The involvement of peri-ocular tissues in PEX, including the eyelid skin, lacrimal gland, conjunctiva, orbital fat and vessels, as well as the optic nerve, has been reported by several previous studies. The peri-ocular effects of PEX include the development of eyelid laxity, conjunctival chalasis, tear film abnormalities, pronounced orbital fat atrophy in response to the administration of prostaglandin analogues in pseudoexfoliative glaucoma, deficient orbital vascular supply and biomechanical changes in both the eyeball and the optic nerve. These effects may have important clinical implications, including increased difficulty in cataract surgery, ocular surface disease and eyelid margin malpositions.

Significant lifespan difference between primary open-angle glaucoma and pseudoexfoliation glaucoma

PURPOSE

Open-angle glaucoma (OAG) is a collective term for various subgroups of glaucoma of which primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEG) are the most common. There is increasing evidence that both conditions have systemic ramifications. We wanted to examine to what extent lifespan and cause of death are influenced by POAG, pseudoexfoliation syndrome (PES), and PEG.

MATERIALS AND METHODS

Of 1864 people who underwent an eye examination in 1985-86, the presence of PES and/or glaucoma, along with date and cause of death were recorded. Based on information from the National Death Registry, the individuals were classified into the following groups of systemic diseases regarded as causing death: Cardiovascular disease (with two subgroups), cerebrovascular disease and neoplasms.

RESULTS

All 1864 persons were followed to death, up to 30 years after examination. No difference in lifespan was observed when comparing OAG (i.e. POAG and PEG together) with the rest of the population. When adjusting for gender and age at inclusion, patients with POAG showed a reduced lifespan in the cardiovascular death group (2.44 years, p = 0.043). When comparing lifespan in the neoplastic group in the glaucoma patients, POAG and PEG, directly against each other, a mean age difference of 6.87 years (p = 0.017) was found.

CONCLUSIONS

POAG patients showed reduced lifespan due to neoplasia and cardiovascular disease. Persons with PES and PEG did not show these lifespan reductions. Our main conclusion is that POAG and PEG, the two main OAG subgroups, are very different disease entities both from an ocular and a systemic point of view.

Association of Rare CYP39A1 Variants With Exfoliation Syndrome Involving the Anterior Chamber of the Eye

IMPORTANCE

Exfoliation syndrome is a systemic disorder characterized by progressive accumulation of abnormal fibrillar protein aggregates manifesting clinically in the anterior chamber of the eye. This disorder is the most commonly known cause of glaucoma and a major cause of irreversible blindness.

OBJECTIVE

To determine if exfoliation syndrome is associated with rare, protein-changing variants predicted to impair protein function.

DESIGN, SETTING, AND PARTICIPANTS

A 2-stage, case-control, whole-exome sequencing association study with a discovery cohort and 2 independently ascertained validation cohorts. Study participants from 14 countries were enrolled between February 1999 and December 2019. The date of last clinical follow-up was December 2019. Affected individuals had exfoliation material on anterior segment structures of at least 1 eye as visualized by slit lamp examination. Unaffected individuals had no signs of exfoliation syndrome.

EXPOSURES

Rare, coding-sequence genetic variants predicted to be damaging by bioinformatic algorithms trained to recognize alterations that impair protein function.

MAIN OUTCOMES AND MEASURES

The primary outcome was the presence of exfoliation syndrome. Exome-wide significance for detected variants was defined as P < 2.5 × 10-6. The secondary outcomes included biochemical enzymatic assays and gene expression analyses.

RESULTS

The discovery cohort included 4028 participants with exfoliation syndrome (median age, 78 years [interquartile range, 73-83 years]; 2377 [59.0%] women) and 5638 participants without exfoliation syndrome (median age, 72 years [interquartile range, 65-78 years]; 3159 [56.0%] women). In the discovery cohort, persons with exfoliation syndrome, compared with those without exfoliation syndrome, were significantly more likely to carry damaging CYP39A1 variants (1.3% vs 0.30%, respectively; odds ratio, 3.55 [95% CI, 2.07-6.10]; P = 6.1 × 10-7). This outcome was validated in 2 independent cohorts. The first validation cohort included 2337 individuals with exfoliation syndrome (median age, 74 years; 1132 women; n = 1934 with demographic data) and 2813 individuals without exfoliation syndrome (median age, 72 years; 1287 women; n = 2421 with demographic data). The second validation cohort included 1663 individuals with exfoliation syndrome (median age, 75 years; 587 women; n = 1064 with demographic data) and 3962 individuals without exfoliation syndrome (median age, 74 years; 951 women; n = 1555 with demographic data). Of the individuals from both validation cohorts, 5.2% with exfoliation syndrome carried CYP39A1 damaging alleles vs 3.1% without exfoliation syndrome (odds ratio, 1.82 [95% CI, 1.47-2.26]; P < .001). Biochemical assays classified 34 of 42 damaging CYP39A1 alleles as functionally deficient (median reduction in enzymatic activity compared with wild-type CYP39A1, 94.4% [interquartile range, 78.7%-98.2%] for the 34 deficient variants). CYP39A1 transcript expression was 47% lower (95% CI, 30%-64% lower; P < .001) in ciliary body tissues from individuals with exfoliation syndrome compared with individuals without exfoliation syndrome.

CONCLUSIONS AND RELEVANCE

In this whole-exome sequencing case-control study, presence of exfoliation syndrome was significantly associated with carriage of functionally deficient CYP39A1 sequence variants. Further research is needed to understand the clinical implications of these findings.

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.

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.

Evaluation of the optic nerve head vessel density in the patients with asymmetric pseudoexfoliative glaucoma: an OCT angiography study

PURPOSE

To evaluate vascular microcirculation changes of the optic nerve head (ONH) in the patients with asymmetric pseudoexfoliative glaucoma (XFG) using optical coherence tomography angiography (OCTA) and to compare vessel density (VD) results with healthy individuals.

METHODS

This prospective study enrolled 120 eyes in total. The eyes were divided into 3 groups: 40 glaucomatous and 40 non-glaucomatous fellow eyes without clinically pseudoexfoliation material (XFM) of patients with asymmetric XFG, and 40 healthy eyes as controls. The optic disc region was evaluated with OCTA (Optovue, Inc., Fremont, CA). VD was assessed as the ratio of the area formed by the vessels in 3 different regions: (1) inside disc; (2) in the peripapillary area defined as a 1-mm wide elliptical annulus around the disc; and (3) in the whole image defined as a 4-mm wide papillary region.

RESULTS

There were significant decreases in VD values of all regions in XFG eyes compared to fellow and control eyes (p < 0.05 for all comparisons). The mean VD values of peripapillary area and whole image were lower in the non-glaucomatous fellow eyes compared with control eyes (p = 0.011 and p = 0.015, respectively). The receiver operating characteristic analysis for differentiating fellow eyes from healthy eyes had highest area under the curve and sensitivity at 90% specificity for superior-hemi (0.811, 65.2%), followed by ppVD (0.775, 61.8%) and whole image (0.743, 55.9%).

CONCLUSIONS

OCTA as a novel imaging may be a valuable structural test in diagnosis and follow-up of glaucoma.

Recent advances in risk factors associated with ocular exfoliation syndrome

Exfoliation syndrome is generally considered a progressive age-related systemic disorder of the extracellular matrix, which is clinically characterized through the observation of flaky white aggregates on ocular tissues. Exfoliation syndrome is directly linked to exfoliative glaucoma in elderly patients, where it is known as the most common identifiable cause of open-angle glaucoma. Despite the identification of various risk factors associated with exfoliation syndrome, the exact pathogenesis of this syndrome has not been fully elucidated. There is a growing number of genome-wide association studies in different populations around the world to identify genetic factors underlying exfoliation syndrome. Besides variants in LOXL1 and CACNA1A genes, new loci have been recently identified which are believed to be associated with exfoliation syndrome. Among different genetic factors, functional variants might help to better understand mechanisms underlying this systemic disorder. Besides genetic factors, epigenetic regulation of different gene expression patterns has been thought to play a role in its pathogenesis. Other factors have been also considered to be involved in the development of exfoliation syndrome at cellular organelles level where mitochondrial impairment and autophagy dysfunction have been suggested in relation to exfoliation syndrome. This review addresses the most recent findings on genetic factors as well as cellular and molecular mechanisms involved in both the development and progression of exfoliation syndrome.

Twelve-Year Incidence and Baseline Risk Factors for Pseudoexfoliation: The Thessaloniki Eye Study (An American Ophthalmological Society Thesis)

PURPOSE

To determine the 12-year incidence of pseudoexfoliation (PEX), baseline risk factors for incident PEX and risk factors for incident pseudoexfoliative glaucoma (PEXG) among those with PEX in an elderly white population.

METHODS

Longitudinal, population-based study in Thessaloniki, the major urban center in Northern Greece. The baseline cohort included 2554 participants ≥60 years old. The surviving cohort was re-examined 12 years later using the same methodology. PEX was defined as typical fibrillar material at the pupil margin and/or on the lens capsule. Glaucoma was defined as both structural and functional damage, irrespective of intraocular pressure (IOP).

RESULTS

Of 1468 eligible subjects in the surviving cohort, 1092 (74%) participated in the follow-up study. The mean age ± standard deviation (SD) at baseline was 68.9 ± 4.6 years. The mean follow-up time was 11.6 ± 1.6 years. The 12-year incidence of PEX was 19.6% (95% confidence interval (CI), 17.1-22.2), with women more likely to be affected than men (Fisher's exact test, P = .0197). Higher axial length was associated with lower odds of incident PEX (odds ratio [OR], 0.72 per mm; 95% CI, 0.57-0.92). PEX at baseline was not associated with an increased likelihood of major vascular disease (P = .9038). Higher baseline IOP (OR, 1.26 per mm Hg; 95% CI, 1.07-1.48) and history of heart attack at baseline (OR, 13.49; 95% CI, 2.85-63.87) were associated with a greater likelihood of developing PEXG among those with PEX. A history of alcohol consumption at baseline was protective of individuals developing PEXG if they had PEX at baseline.

CONCLUSION

This is one of the very few longitudinal population-based studies that has specifically assessed the incidence of PEX. The association with axial length was previously found only in a cross-sectional study. The associations with heart attack and alcohol consumption are new findings. In individuals with baseline PEX, higher IOP at baseline, history of heart attack at baseline, and no alcohol consumption were associated with a greater likelihood of developing glaucomatous damage approximately 12 years later. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

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.