Pseudoexfoliation: normative data and associations. The Central India Eye and Medical Study

Prevalence and Associated Factors of Pseudoexfoliation Syndrome in an Iranian Elderly Population: The Tehran Geriatric Eye Study

PURPOSE

To investigate the prevalence and associated factors of pseudoexfoliation syndrome (PEX) in an Iranian elderly population.

METHODS

This study, a population-based cross-sectional study conducted on individuals ≥60 years in Tehran, the capital of Iran in 2019 using a multi-stage stratified random cluster sampling. All study participants underwent complete ocular examination (including measurement of uncorrected and best-corrected visual acuity, refraction, slit-lamp biomicroscopy). The PEX was diagnosed based on the presence of white fluffy dandruff-like pseudoexfoliative material on the pupillary margin, on the anterior lens capsule, and/or the trabecular meshwork.

RESULTS

Of the 3791 invitees, 3310 participated in the TGES (response rate: 87.3%). After applying exclusion criteria, the data of 3274 individuals were analyzed for this report. The overall prevalence of PEX was 3.63% (95% CI:2.67-4.58) in this study. 81.1% of PEX cases were bilateral. The prevalence of PEX increased significantly with advancing age in a linear trend from 2.38% (95%: 1.27-3.48) in the age group 60-64 years to 6.48% (95%: 2.02-10.95) in the age group ≥80 years (OR = 1.05, p = 0.008). According to the multiple logistic regression model, advancing age (OR: 1.06, p = 0.002) and the presence of cataract (OR: 5.02, p < 0.001) were significantly associated with increased odds of PEX.

CONCLUSION

The results showed a lower prevalence of PEX in the Iranian elderly compared to previous studies on the elderly population. Advancing age and cataracts were the only associated factors of PEX in the present study.

Association between Diabetes and Exfoliation Syndrome

Topic

This systematic review and meta-analysis summarizes the existing evidence for the association of diabetes mellitus (DM) and exfoliation syndrome (XFS).

Clinical Relevance

Understanding and quantifying these associations may aid clinical guidelines or treatment strategies and shed light on disease pathogenesis. The role of DM in determining XFS risk may also be of interest from an individual or public health perspective.

Methods

The study protocol was preregistered on the International Prospective Register of Systematic Reviews with registration number CRD42023429771. We systematically searched PubMed and Embase from inception to June 15, 2023. Screening and full-text review were conducted by 2 independent reviewers. All observational studies reporting an age-adjusted odds ratio (OR) and 95% confidence interval (CI) for the association between DM and XFS among adults were included. Quantitative synthesis involved a random-effects meta-analysis using the DerSimonian-Laird method to generate a pooled OR. Risk of bias was evaluated using the Newcastle-Ottawa Scale.

Results

Fourteen studies (9 cross-sectional and 5 case-control) comprising 47 853 participants were included in the systematic review and meta-analysis. Random-effects meta-analysis indicated no overall association between DM and XFS (OR 0.94; 95% CI, 0.73–1.21; I 2  = 68.5%). However, subgroup analysis revealed a significant inverse association among individuals ≥ 65 years (OR 0.71; 95% CI, 0.54–0.93) versus individuals < 65 years (OR 1.22; 95% CI, 0.80–1.87; P effect modification  = 0.04). The relation between DM and XFS was also inverse in case-control studies (OR 0.75; 95% CI, 0.58–0.97) but was nonsignificant in cross-sectional studies (OR 1.17; 95% CI, 0.83–1.66; P effect modification  = 0.04). Overall risk of bias was low, with tests for publication bias showing P  ≥ 0.06.

Conclusion

This meta-analysis suggests no association between DM and XFS overall, with possible inverse associations of DM with XFS in older populations. However, given the substantial heterogeneity and borderline significance for publication bias, these findings should be interpreted with caution. Our results give insight into the unique etiology and clinical relevance of XFS while proposing the need for larger longitudinal and genetic biomarker studies.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Intraocular pressure and its determinants in a very old population. The ural very old study

Purpose

To explore intraocular pressure (IOP) and its associated parameters in an aged population.

Methods

The epidemiologic Ural Very Old Study (UVOS) conducted in Bashkortostan/Russia included 1526 participants with an age of ≥85 years. Besides a whole series of ocular and systemic examinations, IOP was determined applying non-contact tonometry. Body mass index, diastolic blood pressure and age were the factors used to estimate the cerebrospinal fluid pressure (CSFP).

Results

The study consisted of 904 participants (age: 88.6 ± 2.7 years) with available IOP readings and without anti-glaucomatous therapy. Mean IOP was 14.5 ± 5.1 mmHg (median: 14 mm Hg; Q1:11; Q3:16; 95%CI:8,25) and 14.8 ± 4.6 mmHg (median: 14 mm Hg; Q1:12; Q3:17; 95%CI:8,28) in the right and left eyes, respectively. Higher IOP correlated (multivariable analysis; correlation coefficient r2:0.32) with female sex (P < 0.001), more sedentary lifestyle (P = 0.006), higher estimated CSFP (P < 0.001), higher total protein serum concentration (P < 0.001), stronger hand grip force (P = 0.01), thicker central cornea (P < 0.001), longer axial length (P = 0.01), absence of previous cataract surgery (P = 0.001), higher degree of pseudoexfoliation (P = 0.02, and thinner peripapillary retinal nerve fiber layer thickness (P = 0.004). Using this that model, IOP reading enlarged by 0.22 mmHg (95% CI: 0.09, 0.35) for each increase in estimated CSFP by 1 mm Hg, by 0.03 mm Hg (95% CI: 0.02,0.05) for each thickening in central corneal thickness by 1 μm, by 0.56 mm Hg (95%CI: 0.13,1.00) for each axial elongation by 1 mm, and by 0.40 mmHg (95% CI: 0.06,0.74) for each increase in the degree of pseudoexfoliation, and it decreased by 0.40 mmHg (95% CI: 0.06,0.74) by cataract surgery.

Conclusions

In this study population aged 85+years, IOP readings showed similar relationships as in younger study populations, including positive associations with higher estimated CSFP and longer axial length and a negative association with cataract surgery.

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.

Evaluating the impact of ocular UV exposure for the development for pseudoexfoliation syndrome in a South Indian population

CLINICAL RELEVANCE

Pathophysiology of pseudoexfoliation syndrome (XFS) can be influenced by environmental factors such as solar exposure/occupational factors and genetic factors.

BACKGROUND

The study aims to assess the association of lifetime ocular UV exposure and its impact on the risk of development of XFS.

METHODS

All eligible subjects underwent a comprehensive ocular examination. XFS was defined as precipitates on the pupillary border, cornea, and angle of anterior chamber or lens in at least one eye without any clinical signs of glaucoma. A standardised questionnaire was administered to assess the lifetime UV exposure. Conjunctival ultraviolet autofluorescence (CUVAF) photography was taken to detect the conjunctival changes with exposure to UV radiation. Ascorbic acid concentration in the aqueous humour was measured.

RESULTS

A total of 404 subjects of which 274 (controls) and 130 (XFS cases) were studied. There were 204 males (50.5%) and 200 females (49.5%).Lifetime UV exposure (OR: 1.14, 95% CI: 1.02-1.30, p: 0.032), CUVAF damage (OR: 1.03, 95% CI: 1.01-1.06, p: 0.008) and outdoor worker (OR: 1.87, 95% CI: 1.18-3.00, p: 0.008) were positively associated with XFS. Usage of spectacles (OR: 0.63, 95% CI: 0.39-0.95, p: 0.030) and ascorbic acid concentration in aqueous (OR: 0.47, 95% CI: 0.23-0.99, p: 0.038) were found to be protective against XFS.

CONCLUSION

Besides genetic factors, environmental factors such as lifetime ocular UV exposure and outdoor work are significantly associated with the risk of XFS. CUVAF can be used as a non-invasive tool to detect preclinical sun damage in outdoor workers.

Correlation between retinal nerve fiber layer thickness and anterior segment parameters in patients with pseudoexfoliation: A cross-sectional comparative study

PURPOSE

The purpose of this study was to assess the retinal nerve fiber layer (RNFL) thickness in patients with pseudoexfoliation (PXF) and to correlate it with anterior segment parameters such as intraocular pressure (IOP), central corneal thickness (CCT), pigments in angle structures, and grades of PXF.

METHODOLOGY

This was a cross-sectional comparative study in a tertiary care center. Patients having unilateral PXF were categorized as group 1. Age- and sex-matched healthy controls were categorized as group 2. All subjects underwent IOP measurement, CCT measurement, and retinal nerve fiber thickness measurement. Subjects in group 1 also underwent gonioscopy and perimetry. Data were entered and analyzed using the IBM-SPSS program (version 20.0); Chicago, IL.

RESULTS

Mean RNFL thickness in group 1 was 85.91 ± 22.237 μ and in group 2 was 106.65 ± 6.1 μ. The mean RNFL thickness in patients with PXF syndrome was 103.38 ± 5.815 μ and in patients with PXF glaucoma was 67.82 ± 17.984 μ. The mean CCT in patients with PXF syndrome was 516.41 ± 23.03 μ and in patients with PXF glaucoma was 507 ± 33.05 μ and control group was 526.6 m. The mean IOP in patients with PXF syndrome was 8 ± 6.01 mmHg; in patients with PXF glaucoma was 17.21 ± 7.33 mmHg; and in the control group was 14.12 ± 2.693 mmHg. There was a negative correlation between IOP and RNFL thickness, and a positive correlation between CCT and RNFL thickness, but it was not statistically significant. A statistically significant correlation was found between grades of PXF and RNFL thinning with a correlation coefficient of 0.437 (P = 0.001).

CONCLUSION

Patients with PXF have a lower CCT, higher mean IOP, and RNFL thinning compared to normal subjects. The presence of grade 3 PXF (on the lens surface edge) showed a statistically significant correlation with RNFL thinning.

Is There an Association Between Pseudoexfoliation and Pterygium? An Observational Study in a Semi-arid District of South India

Introduction Pseudoexfoliation (PXF) has a varied impact on the eye and has a complex relationship with pterygium and cataracts. We explored this study to estimate the proportion of PXF and its association with pterygium in cataract patients from a semi-arid district in South India. Methods This retrospective observational study was conducted at Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research, a tertiary care referral center in Kolar, India. Cataract patients attending the hospital between December 2020 and August 2022 were included based on non-probability sampling. Three hundred fifty-two patients were included based on the inclusion and exclusion criteria, and their records on demographic details and ocular examination were collected. Results Out of 352 patient records, 184 (52.27%) were males, with the mean age being 67.84 ± 13.08 years. In all, 95% of the patients were agricultural laborers exposed to sunlight and dust for more than six hours daily. It was observed that the proportion of PXF and pterygium in the study population was 28.40% (100) and 56.33% (199), respectively. The mean age of the PXF patients was 75.53 ± 6.26 years. The association of PXF with pterygium was statistically significant (p < 0.05). Conclusion PXF is one of the significant causes of complications in cataract surgery and blindness, which can be detected only in the end stages. This study draws a statistically significant association between pterygium and PXF. Identifying preclinical cases of PXF and halting its progression by avoiding risk factors such as prolonged exposure to sunlight, UV radiation, and dust should be focused on risk-prone geographical areas.

Dynamic volume-rendered optical coherence tomography pupillometry

PURPOSE

To assess intrapupillary space (IPS) changes in healthy subjects with regard to decreased iris motility in patients with pseudoexfoliation glaucoma (PEXG) or non-arteritic anterior ischaemic optic neuropathy (NAION) in a feasibility study in a clinical environment.

METHODS

Scotopic and photopic IPS measurements using three-dimensionally rendered swept-source optical coherence tomography (SS-OCT) data were obtained and compared for all subjects. Intrapupillary space (IPS) parameters were evaluated such as absolute volumetric differences, relative light response for volumetric ratios and pupillary ejection fraction (PEF) for functional contraction measurements.

RESULTS

From a total of 122 IPS from 66 subjects, 106 IPS were eligible for comparison providing values for 72 normal, 30 PEXG and 4 NAION eyes. In healthy, PEXG and NAION subjects, scotopic overall mean IPS was 8.90, 3.45 and 4.16 mm³ , and photopic overall mean IPS was 0.87, 0.74 and 1.13 mm³ , respectively. Three-dimensional contractility showed a mean absolute difference of 8.03 mm³ for normals (defined as 100% contractility), 2.72 mm³ for PEXG (33.88% of normal) and 3.03 mm³ for NAION (38.50% of normal) with a relative light response ratio between scotopic and photopic volumes of 10.26 (100%), 4.69 (45.70%) and 3.67 (35.78%), respectively. Pupillary ejection fraction (PEF) showed a contractile pupillary emptying of 88.11% for normals, 76.92% for PEXG and 70.91% for NAION patients.

CONCLUSION

This 3D pupillometry OCT assessment allows for quantitative measurements of pupil function, contractility and response to light. More specifically, PEF is presented as a potential (neuro)-pupillary outcome measure that could be useful in the monitoring of ophthalmic disorders that affect pupillary function.

Association of the CYP39A1 G204E genetic variant with increased risk of glaucoma and blindness in patients with exfoliation syndrome

PURPOSE

Carriers of functionally deficient mutations in the CYP39A1 gene have been recently reported to have a 2-fold increased risk of exfoliation syndrome (XFS). The aim of this study was to evaluate the risk of blindness and related clinical phenotypes of XFS patients carrying the loss-of-function CYP39A1 G204E mutation in comparison to XFS patients without any CYP39A1 mutation.

DESIGN

Retrospective case study PARTICIPANTS: 35 patients diagnosed with XFS carrying the CYP39A1 G204E mutation and 150 XFS patients without any CYP39A1 mutation, who were randomly selected from the Japanese XFS cohort.

METHODS

Two-sided Fisher's Exact Test with an α-level <0.05 was used to estimate the significance of the calculated Odds Ratio (OR) for all categorical measures. Comparisons between groups of subjects were performed using linear mixed effect models with group as random effect and taking possible dependence between eyes within a subject into account.

MAIN OUTCOME MEASURES

Primary analysis compared the incidence of blindness (defined as visual acuity [VA]<0.05 decimal), prevalence of exfoliation glaucoma (XFG), history of glaucoma surgery, and indices of glaucoma severity such as visual field mean deviation (MD), intraocular pressure (IOP) and vertical cup-disc ratio (CDR), between CYP39A1 G204E carriers and those without any CYP39A1 mutation.

RESULTS

The overall risk for blindness was significantly higher in XFS patients carrying the CYP39A1 G204E variant (10/35 [28.6%]) compared to XFS patients without any CYP39A1 mutations (8/150 [5.3%]; OR7.1 [95%CI:2.7-20.2]; p<0.001). A higher proportion of XFS patients with the CYP39A1 G204E mutation (23/35 [65.7%]) had evidence of XFG in at least one eye compared to the comparison group (41/150 [27.3%]; OR5.1 [95%CI:2.4-11.4]; p<0.0001). Significantly higher peak IOP, larger vertical CDR and worse visual field MD were also found in CYP39A1 G204E variant carriers (p<0.001). Additionally, patients with the CYP39A1 G204E mutation (18/35 [51.4%]) required more laser or glaucoma surgical interventions compared to those without any CYP39A1 mutation (32/150 [21.3%], p<0.001).

CONCLUSIONS

Patients with XFS carrying the CYP39A1 G204E mutation had significantly increased risk of blindness, higher occurrence of XFG and more severe glaucoma compared to patients with XFS without any CYP39A1 mutation.

Twelve-Year Incidence of Open-angle Glaucoma: The Thessaloniki Eye Study

OBJECTIVE

The objective of this study was to determine the 12-year incidence of open-angle glaucoma (OAG), with further classification into primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG), in an elderly White population.

DESIGN

A longitudinal, population-based study in urban Northern Greece.

PARTICIPANT

Surviving cohort of the 2554 Thessaloniki Eye Study subjects 60 years and above who had the baseline examination.

METHODS

The surviving cohort was re-examined 12 years after baseline, using the same methodology and the same standard operating procedures as in the baseline examination. The definitions of glaucoma and pseudoexfoliation were consistent throughout the study. The 12-year incidences of OAG, POAG, and PEXG with corresponding 95% confidence intervals (CIs) were calculated for the whole study population, consisting of clinic-visit and home-visit participants. The population at risk was defined as those who did not meet the study criteria for the diagnosis of glaucoma in either eye at baseline.

MAIN OUTCOME MEASURES

Twelve-year incidence of OAG, with further classification into POAG and PEXG.

RESULTS

Of 1468 eligible subjects in the surviving cohort, 1092 were examined (participation rate 74%). Mean age at baseline was 68.9±4.6 years. Mean follow-up time was 11.6±1.6 years. The 12-year incidence of OAG was 4.4% (95% CI: 3.3-5.8); 0.37% per year. In the overall population the incidence of POAG and PEXG was 2.1% (95% CI: 1.3-3.2) and 2.3% (95% CI: 1.5-3.4), respectively. The corresponding incidence proportions were 2.9 (95% CI: 1.8-4.3) in those without PEX and 8.9 (95% CI: 5.8-12.9) in those with PEX at baseline and/or incidence. The latter was strongly associated with higher odds for incident glaucoma (odds ratio=3.34, 95% CI: 1.83-6.08, P<0.001). Of all incident OAG cases, 11.1% (95% CI: 4.4-24) had baseline intraocular pressure >21 mm Hg.

CONCLUSIONS

The incidence of OAG was similar or higher compared with other White populations. The incidence of glaucoma in those with PEX was higher compared with the incidence of glaucoma in those without PEX.

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.

Early-onset Exfoliation Syndrome: A Literature Synthesis

PRECIS

We conducted a literature review of younger patients with exfoliation syndrome (XFS) in an attempt to identify case similarities and better understand disease etiology.

PURPOSE

XFS that predisposes to secondary glaucoma is a strongly age-related condition. We performed a literature review of XFS and exfoliation glaucoma (XFG) in patients aged younger than 40 years to examine potential common characteristics and gain clues to its etiology.

METHODS

We conducted a broad literature search with appropriate keywords and manually extracted key demographic and ocular features on younger XFS and XFG cases. Articles that did not provide past ocular history on early-onset XFS/XFG were excluded.

RESULTS

We identified 12 cases of XFS and XFG in patients from 13 to 40 years old (8 females; 11 White; 5 from Iran). All had past ocular history remarkable for intraocular surgery for other glaucoma conditions (7 cases), other ocular diseases (3 cases), or ocular trauma (2 cases).

CONCLUSIONS

All reported early-onset XFS and XFG cases arise in the setting of events that produced a significant disruption of the blood-aqueous barrier. Understanding the metabolic alterations of aqueous humor from such cases could provide clues regarding how exfoliation material forms.

Macular pigment optical density change analysis in primary open-angle glaucoma and pseudoexfoliation glaucoma

PURPOSE

We aimed to investigate whether macular pigment optical density (MPOD) has a diagnostic value by comparing MPOD and retinal nerve fiber layer (RNFL), ganglion cell layer++ (GCL++) of patients with primary open-angle glaucoma (POAG) and pseudoexfoliation (PEX) glaucoma and normal individuals.

METHODS

We included in the study 54 eyes of 34 patients with diagnosis POAG, 40 eyes of 25 patients with PEX glaucoma and 40 eyes of 20 normal individuals. The MPOD measurements of the cases were performed in the MPOD mode of the fundus fluorescein angiography (Carl Zeiss Visucam Meditec, Germany) device while the pupils were in dilated status. RNFL and GCL++ measurements of all individuals included in the study were done by swept source optical coherence tomography (DRI Triton swept source optical coherence tomography; Topcon, Tokyo, Japan). Intraocular pressures of all three groups were measured by Applanation tonometer. The relationship between MPOD, RNFL and GCL++ values were examined. Patients with additional ophthalmic disease, intraocular surgery, history of chronic drug use, and smokers were excluded in the study.

RESULTS

MPOD mean and MPOD max values were significantly higher in patients with PEX glaucoma than POAG and control group (p < 0.05). MPOD mean and MPOD max measurements were not different when compared to POAG patients and control group (p > 0.05). RNFL and GCL++ measurements were found significantly thinner in patients with POAG and PEX glaucoma compared to the control group (p < 0.001). There was no correlation between MPOD values and RNFL or GCL++. MPOD max values show a very high correlation with age in a statistically significant positive direction (r = 0.90, p < 0.001). The average age of PEX glaucoma group was higher than the control group (p = 0.006). There was no age difference between the PEX glaucoma group and the POAG group (p > 0.05). Also, there was no difference in age between POAG and control groups. In POAG and PEX glaucoma groups, mean intraocular pressure values are significantly higher than the control group.

CONCLUSIONS

In our study, no MPOD change was observed in the POAG group, while a statistically significant increase in MPOD was found in the PEX glaucoma group. As a result of these findings, we think that PEX syndrome also affects the posterior segment. Well-organized, large, prospective, and randomized studies should be developed for preventive treatment to the negative effects of PEX syndrome on all eye tissues.

Pseudoexfoliation syndrome and relating factors in a rural Japanese population: the Kumejima Study

PURPOSE

To report the prevalence of pseudoexfoliation (PEX) syndrome and glaucoma associated with PEX (PEX-G) and their relating factors of them in a south-western island of Japan.

METHODS

A population-based survey of all residents aged ≥ 40 years was conducted in Kumejima, Okinawa, Japan, and 3762 subjects (participation rate, 81.2%) underwent detailed ophthalmic examinations. Presence of PEX material on the lens capsule, iris surface and/or pupillary margin was determined by slit-lamp biomicroscopy. Glaucoma was diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology.

RESULTS

In subjects aged ≥ 40 years, prevalence rates of PEX syndrome, PEX without glaucoma and PEX-G in at least one eye were 1.5% (95% confidence interval [CI]: 1.0-1.9%), 1.3% (95% CI: 0.9-1.7%) and 0.1% (95% CI: 0.0-0.2%), respectively, excluding eyes after cataract surgery; and 2.8% (95% CI: 2.3-3.3%), 2.2% (95% CI: 1.8-2.6 %) and 0.4% (95% CI: 0.2-0.6%), respectively, including eyes after cataract surgery. Cataract surgery had been performed in 61% of subjects with PEX in at least one eye; presence of PEX showed no significant effects on the intraocular pressure (IOP). A multivariate analysis showed that PEX was associated with older age (p < 0.0001, odds ratio: 1.10 [95% CI: 1.07-1.13]) and working outdoors (p = 0.0395, odds ratio: 2.18 [95% CI: 0.99-4.82]).

CONCLUSIONS

The prevalence rates of PEX syndrome and PEX-G in a south-western island of Japan were reported. PEX showed no significant effect on IOP, and age and working outdoors were significantly related with PEX.

Prevalence and Associated Factors of Pseudoexfoliation in a Russian Population: The Ural Eye and Medical Study

PURPOSE

To assess the prevalence of pseudoexfoliation (PEX) and its associations in a Russian population.

DESIGN

Population-based cross-sectional study.

METHODS

Setting: Ufa capital of Bashkortostan, Russia and a rural region in Bashkortostan.

PARTICIPANTS

the Ural Eye and Medical Study included 5,899 (80.5%) of 7,328 eligible individuals (mean age, 59.0 ± 10.7 years old; range, 40-94 years).

OBSERVATION PROCEDURES

as part of an ophthalmological and general examination, presence and degree of PEX was assessed using slit-lamp biomicroscopy after medical pupillary dilation.

MAIN OUTCOME MEASUREMENTS

PEX prevalence.

RESULTS

After excluding pseudophakic and aphakic individuals, the study included 5,451 (92.4%) participants. PEX prevalence (3.6%; 95% confidence interval [CI]:3.1-4.1), increased from 0.5% (95% CI, 0.1-0.9) in individuals 40 to <50 years old to 10.4% (95% CI, 5.0-15.8) in individuals aged 80+ years. Higher PEX prevalence was associated (multivariate analysis) with older age (odds ratio [OR], 1.09; 95% CI, 1.07-1.11; P < 0.001), Russian ethnicity (OR, 1.50; 95% CI, 2.09-1.11;P = 0.02), higher prevalence of open-angle glaucoma (OR, 2.40; 95% CI, 1.36-4.23;P = 0.003), and higher intraocular pressure (OR, 1.06; 95% CI, 1.02-1.09;P = 0.001). PEX prevalence was not significantly associated with gender (P = 0.49), region of habitation (P = 0.11), body mass index (P = 0.68), level of education (P = 0.26), smoking (P = 0.11), alcohol consumption (P = 0.52), history of cardiovascular or cerebrovascular disease (P = 0.94) and dementia (P = 0.77), prevalence of diabetes mellitus (P = 0.16), arterial hypertension (P = 0.45), chronic obstructive pulmonary disease (P = 0.73), chronic kidney disease (P = 0.09), and hearing loss (P = 0.31).

CONCLUSIONS

In this typical, ethnically mixed, population from Russia with an age of 40+ years, PEX prevalence (3.6%; 95% CI, 3.1-4.1) was associated with older age, Russian ethnicity, higher intraocular pressure and open-angle glaucoma. It was independent of any systemic parameter including diabetes, arterial hypertension, previous cardiovascular and cerebrovascular diseases and dementia.

Epidemiology of Exfoliation Syndrome

BACKGROUND

From a historical standpoint the epidemiology of exfoliation syndrome (XFS) is one of the most controversial subjects in ophthalmic literature. Current literature abounds with studies on the prevalence of XFS in various ethnic populations and clearly XFS is a common condition, but its true prevalence is difficult to ascertain. Overall, XFS is considered to be the most common identifiable cause of glaucoma worldwide.

PURPOSE

This review critically examines the published literature documenting the epidemiological features of XFS and attempts to provide a unified concept concerning existing controversy.

METHODS

A critical review of selected literature pertaining to the epidemiology of XFS.

RESULTS

It is well established that XFS and the ensuing exfoliative glaucoma have a worldwide prevalence and a progressively increasing age-related incidence. The prevalence of the condition is significantly underestimated. Many past studies have proposed clear geographic variations within and between ethnic groups. In contrast, there has also been some epidemiological evidence suggesting that the prevalence of XFS is similar within various ethnic groups. Published literature fails to address the potential role and impact of suspected exfoliation cases in the reported prevalence figures of the condition. Incidence figures for the condition are limited and vary extensively. Cumulative data have indicated that several, as yet partly understood genetic, ethnic, and environmental factors contribute to the varied prevalence of this condition.

CONCLUSIONS

Further understanding on XFS epidemiology is needed. Only a future large prospective study conducted by the same investigators, using similar methodologies for different ethnic populations will prove beyond doubt the hypothesis that significant geographic variations exist. Since patients with exfoliative glaucoma are at significant risk of losing vision it is vital to elucidate the causes and the risk of developing XFS. To reach this goal, it is important to better delineate the early changes of XFS and to focus research efforts on modifiable factors for XFS development.

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.

Intraocular Pressure and Its Associations in a Russian Population: The Ural Eye and Medical Study

PURPOSE

To assess the normal distribution of intraocular pressure (IOP) and its associations with ocular, medical, and socioeconomic factors in a Russian population.

DESIGN

Population-based cross-sectional study.

METHODS

The Ural Eye and Medical Study conducted in a rural and urban area in Ufa/Bashkortostan included 5899 (80.5%) participants out of 7328 eligible individuals aged 40+ years. IOP was measured by noncontact tonometry.

RESULTS

After exclusion of individuals after glaucoma surgery or with antiglaucomatous therapy, mean IOP was 13.6 ± 3.8 mm Hg (median: 13 mm Hg; range: 3-49 mm Hg; 95% confidence interval [CI]: 8-23 mm Hg). The IOP range within the mean ± 2 standard deviations was 6.0-21.2 mm Hg. In multivariable analysis higher IOP was associated (regression coefficient r: 0.40) with the systemic parameters of female sex (nonstandardized regression coefficient B: 0.44; 95%CI: 0.22, 0.66; standardized regression coefficient beta: 0.06; P < .001), urban region of habitation (B: -0.27; 95% CI: 0.51, 0.03; beta: 0.03; P = .03), Russian ethnicity (B: 0.47; 95% CI: 0.20, 0.74; beta: 0.05; P = .001), higher body mass index (B: 0.06; 95% CI: 0.04, 0.08; beta: 0.08; P < .001), lower physical activity score (B: -0.02; 95% CI: -0.03, -0.002; beta: -0.03; P = .02), higher prevalence of diabetes mellitus (B: 0.42; 95% CI: 0.08, 0.76; beta: 0.03; P = .02), higher systolic blood pressure (B: 0.01; 95% CI: 0.01, 0.02; beta: 0.08; P < .001), fewer days with intake of fruits (B: -0.07; 95% CI: -0.12, -0.01; beta: 0.03; P = .01), lower blood concentration of bilirubin (B: -0.01; 95% CI: -0.02, -0.003; beta: -0.04; P = .008) and urea (B: -0.11; 95% CI: -0.17, -0.04; beta: -0.04; P = .003), worse best-corrected visual acuity (B: 0.64; 95% CI: 0.38, 0.90; beta: 0.13; P < .001), thicker central corneal thickness (B: 0.036; 95% CI: 0.033, 0.039; beta: 0.32; P < .001), higher anterior corneal refractive power (B: 0.11; 95% CI: 0.04, 0.18; beta: 0.05; P = .003), lower anterior chamber depth (B: -0.57; 95% CI: -0.83, -0.30; beta: -0.07; P < .001) (or lower prevalence of cataract surgery [B: -0.78; 95% CI: -1.44, -0.13; beta: -0.03; P = .02]), longer axial length (B: 0.30; 95% CI: 0.18, 0.42; beta: 0.07; P < .001), and higher prevalence of pseudoexfoliation (B: 1.08; 95% CI: 0.52, 1.63; beta: 1.01; P < .001). Measured IOP decreased by 0.36 mm Hg (95% CI: 0.33, 0.39) for each increase in central corneal thickness by 10 μm.

CONCLUSIONS

IOP was associated with a multitude of systemic and ocular parameters, the associations of which may be considered in defining the normal range of IOP.

Pseudoexfoliation Syndrome and Antidepressant Drug Use

Objectives:

To investigate the relationship between pseudoexfoliation syndrome (PES) and the use of antidepressant medications.

Materials and Methods:

This population-based, cross-sectional study included 2,017 of 2,356 invited subjects who were randomly selected from the Turkish Statistical Institute database (www.turksat.gov.tr/) as part of an epidemiologic study which specifically aimed to detect the prevalence of PES in the province of Eskişehir. During the examination, a detailed questionnaire was administered to determine physician-diagnosed systemic disease and drug use.

Results:

Eight of the 2,017 participants in the study were excluded for various reasons (2 with posterior synechiae, 2 with corneal opacity, 1 uncooperative patient, 1 eviscerated patient, 1 with active adenoviral keratoconjunctivitis, and 1 with a history of angle closure). PES was detected in 100 (5%) of the 2,009 patients whose data were analyzed. The percentage of subjects with concurrent antidepressant drug use in the PES and non-PES non-glaucoma groups were 4.1% (n=3) and 1.1% (n=21), respectively. The difference between the two groups was statistically significant (p=0.024). In addition, the use of medications for hypertension (p<0.001) and coronary artery disease (p=0.009) was also higher in the PES group.

Conclusion:

The higher prevalence of antidepressant drug use in patients with PES may be related to the processes of vascular damage and inflammation common to the pathogenesis of both PES and depression, as well as the high rate of chronic systemic comorbidities in these patients.

Frequency and surgical difficulties associated with pseudoexfoliation syndrome among Indian rural population scheduled for cataract surgery: Hospital-based data

Purpose:

To study the frequency and intraoperative difficulties associated with pseudoexfoliation (PXF) syndrome at a tertiary eye care center in a rural central India.

Methods:

This study included patients scheduled for cataract surgery who were diagnosed with PXF syndrome. All patients underwent a complete ophthalmologic evaluation, including slit-lamp examination, tonometry, gonioscopy, and ophthalmoscopy before the surgery. Cataract surgeries were performed by a single surgeon who reported the intraoperative difficulties.

Results:

In total, 1022 phakic eyes of 1823 patients were evaluated, 226 of whom (22.1%) were diagnosed with PXF syndrome. Most eyes (n = 81, 35.8%) with PXF syndrome were ≥81 years old. Eighty-six eyes (38.1%) had bilateral involvement, whereas 70 (30.9%) had right or left eye involvement. Further, PXF material was distributed on the iris, pupil, and lens in 70 eyes (30.9%) and on the pupillary margin in 36 eyes (15.9%). The mean pupillary dilation was 5.1 (±1.4) mm in patients with PXF syndrome compared with 7.2 (±1.6) mm in those without it (P = 0.03). Grade VI cataract was observed in 93 eyes (41.2%) and hypermature cataract was the most commonly observed cataract stage. Twenty-one eyes (9.3%) had increased intraocular pressure. Intraoperative difficulties were encountered in 62 eyes (27.4%) with poor pupillary dilation being the most common problem (32 eyes, 14.2%), followed by zonular dehiscence (18 eyes, 8%).

Conclusion:

This hospital-based study showed that PXF syndrome is common in Indian rural population and that the intraoperative complication rate in these patients is high.

The Incidence of Retinal Vein Occlusion in Patients with Pseudoexfoliation Glaucoma: A Retrospective Cohort Study

PURPOSE

The aim of this study was to evaluate pseudoexfoliation (PXF) as an independent risk factor for the occurrence of retinal vein occlusion (RVO).

METHODS

This is a retrospective cohort study on the records of 300 PXF glaucoma patients (PXF group), 300 non-PXF glaucoma patients, and 599 nonglaucoma non-PXF (nGnP group) patients.

RESULTS

Multivariate analysis resulted in a significant probability for RVO in the PXF (p = 0.005; OR 2.29 [1.13-4.68]) and non-PXF glaucoma groups (p = 0.005; OR 3.03 [1.55-5.94]) compared to the nGnP group. There was a much higher probability for central RVO (CRVO) in the PXF (p = 0.013; OR 3.64 [1.39-9.49]) and non-PXF glaucoma groups (p = 0.013; OR 3.78 [1.48-9.65]) compared to the nGnP group. After matching and excluding neovascular glaucoma, no significant difference was found between the PXF and non-PXF glaucoma groups regarding RVO (p = 0.541), CRVO (p = 0.092), and branch RVO (p = 0.774).

CONCLUSIONS

PXF and other types of glaucoma are associated with RVOs, mainly CRVO. PXF was not found to be an independent risk factor for CRVO.

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.

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.

The Prevalence of Pseudoexfoliation and the Long-term Changes in Eyes With Pseudoexfoliation in a South Indian Population

PURPOSE

To report the prevalence, long-term changes and associated factors for pseudoexfoliation (PEX) in a population aged 40 years and above from rural and urban south India.

MATERIALS AND METHODS

At baseline (the Chennai Glaucoma Study), 7774 subjects were examined. After 6 years, as a part of the incidence study, 133 of the 290 subjects diagnosed with PEX at baseline were reexamined for long-term changes. Participants had detailed examination at base hospital.

RESULTS

At baseline PEX was noted in 290 [3.73%, 95% confidence interval (CI), 3.3-4.2] subjects. It was associated with glaucoma in 24 (8.3%), ocular hypertension (OHT) in 21 (7.2%), and occludable angles in 24 (8.3%) subjects. The age-adjusted and sex-adjusted prevalence was 3.41% (95% CI, 3.39-3.43). Increasing age was a significant associated factor. Using the 40- to 49-year age group as a reference, the odds ratio increased from 8.4 (95% CI, 4.1-17.1) for the 50- to 59-year age group to 51.2 (95% CI, 25.8-101.6) for the 70 years and above age group. Other associated factors were rural residence (P<0.001), higher intraocular pressure (P<0.001), cataract (P<0.001), being underweight (P=0.01), manual labor (P=0.03), and aphakia (P<0.001). Of the 133 subjects reexamined, 8 (6.0%) subjects developed glaucoma and all had OHT at baseline. Rates of cataract surgery were (P<0.001) higher in subjects with PEX.

CONCLUSION

Prevalence of PEX was higher in rural population and baseline OHT was a significant factor for conversion to glaucoma.

Electroneuromyographic findings in pseudoexfoliation syndrome

PURPOSE

To examine peripheral electroneuromyographic findings in patients with ocular pseudoexfoliation syndrome (PEX) and to compare them controls without PEX.

METHODS

A case-control study design was used to examine 31 patients with PEX and compare the findings with those of 31 age- and sex-matched healthy controls. All patients underwent complete ophthalmologic examination that included peripheral electroneuromyography examination. Motor and sensorial nerve conduction of the median, ulnar, tibial, peroneal, and sural nerve and the sympathetic skin response were measured.

RESULTS

The average sensorial nerve latency of the ulnar and sural nerve was significantly longer in the PEX group compared to the control group (p < 0.05). The average sensorial nerve conduction amplitude and the velocity of the ulnar and sural nerve were significantly lower in the PEX group (p < 0.05).

DISCUSSION

Peripheral nerves, especially sensorial fibers, appear to be affected in PEX patients. These finding may indicate that PEX is a systemic disease.

Prevalence of pseudoexfoliation syndrome and its association with ocular and systemic diseases in Eskisehir, Turkey

AIM

To investigate the prevalence of pseudoexfoliation syndrome (PEX) and its associations with ocular and systemic diseases in a population sample aged over 40y.

METHODS

A total of 2356 subjects were randomly chosen for the sample population based on the database of the Turkish Statistical Agency in Eskisehir. Of the invited 2356 subjects, 2017 subjects participated, out of which 2009 were eligible for the study. Systemic diseases, drug use, smoking and body mass index were assessed using questionnaires. Measurements of central corneal thickness (CCT), anterior chamber depth (ACD) and intraocular pressure (IOP) were performed during June to December, 2015. After pupillary dilation, the anterior segment and lenses were evaluated using a slit lamp.

RESULTS

Prevalence of PEX in this sample was 5.0% (n=100). Of patients with PEX, 26% also had glaucoma. Incidence of cataracts, and using drugs for hypertension, cardiac and psychiatric conditions was higher in patients with PEX compared to normal cases (P<0.05). Hearing loss was more common in PEX cases (34.0% vs 5.4%; P<0.001). The mean CCT, ACD and IOP were not significantly different between PEX and non-PEX cases.

CONCLUSION

This study is the first population-based, randomized trial in Turkey. Prevalence of PEX in patients over 40 years old was found to be 5.0%. Besides glaucoma and cataract, hypertension, hearing loss, using drugs for cardiac and psychiatric diseases were associated with PEX.

[Long-term results of phacoemulsification in pseudoexfoliation syndrome]

INTRODUCTION

The prevalence of pseudoexfoliation syndrome is estimated at 8 % of all cataracts operated within our institution. The goal of our study was to describe the frequency of intraoperative and postoperative complications and long-term anatomical and functional results of phacoemulsification in pseudoexfoliation syndrome.

PATIENTS AND METHODS

A retrospective observational study of a series including 103 patients (107 eyes) with cataract associated with pseudoexfoliation syndrome admitted between January 2010 and September 2014. All patients underwent phacoemulsification.

RESULTS

The average age of our patients was 72.5±6 years. The average initial corrected visual acuity was 0.52±0.14LogMAR. The cataract was grade C3N3 in 58 % of cases. The pseudoexfoliation syndrome was bilateral in 69 % of cases. Pupillary dilatation was≤6mm in 54 % of cases. Among intraoperative complications, zonular dialysis was found in 1.8 % of cases. Posterior capsular rupture and vitreous loss was noted at 5.4 % of patients. The incidence of secondary cataract was 31.7 % at 12 months. The mean postoperative best corrected visual acuity was 0.13±0.15 LogMAR.

DISCUSSION

The small pupil associated with high grade of the cataracts in our series explains the slightly higher frequency of intraoperative zonular dialysis. Cataract surgery by phacoemulsification allows for a statistically significant improvement in visual acuity (P<0.001). The incidence of secondary cataract, the main postoperative complication, is higher in our series compared to data in the literature.

CONCLUSION

Pseudoexfoliation syndrome is common in our country. Functional results of phacoemulsification are very satisfactory, and secondary cataract is the main complication. A meticulous search for pseudoexfoliation is mandatory during the initial examination in order to reduce intraoperative complications. Careful removal of the cortex and systematic polishing of the lens capsule should limit the incidence of secondary cataracts.

Ethnicity-Based Differences in the Association of LOXL1 Polymorphisms with Pseudoexfoliation/Pseudoexfoliative Glaucoma: A Meta-Analysis

Pseudoexfoliation (PEX) is an age-related disorder of the extracellular matrix; it is strongly associated with glaucoma, the leading cause of irreversible blindness worldwide. We conducted an ethnic-based meta-analysis of the association of LOXL1 polymorphisms with PEX/pseudoexfoliative glaucoma (PEXG). Association studies were retrieved systematically from PubMed, EMBASE, and Web of Knowledge. Allelic and genotype frequencies of rs3825942, rs1048661, and rs2165241 were compared between PEX/PEXG and controls. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using a random effects model. Overall, 39 independent cohorts were included. Rs3825942 (G) was an at risk allele for PEX/PEXG in Caucasians, Japanese, Koreans, Chinese, South Asians, and Middle Easterners, but protective in Black South Africans (OR = 0.10, 95%CI:0.06-0.16). Rs1048661 (G) was an at risk allele for PEX/PEXG in Caucasians, South Asians, Middle Easterners and Black South Africans, but was protective in Japanese (OR = 0.03, 95%CI:0.02-0.06) and Koreans (OR = 0.10, 95%CI:0.05-0.22). These associations we-re confirmed for the genotypic recessive models. Rs2165241 (C) was a protective allele for PEX/PEXG in Caucasians, but was an at risk allele in Japanese (OR = 7.49, 95%CI:3.22-17.41) and Koreans (OR = 6.63, 95%CI:2.60-16.90). This was confirmed for the genotypic dominant model. Other genetic and/or environmental factors may modify the effect of LOXL1 polymorphisms in certain ethnic groups.

Pseudoexfoliation syndrome at a Singapore eye clinic

Background

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

Methods

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

Results

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

Conclusion

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

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.

Role of an extracellular chaperone, Clusterin in the pathogenesis of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

Pseudoexfoliation (PEX), an age related disorder is a prominent contributor to secondary glaucoma. Earlier studies have suggested involvement of clusterin in the development of PEX. We designed a case-control study to understand the role of clusterin single nucleotide polymorphisms (SNPs) in PEX and analyzed the role of risk alleles in the disease. Genotyping of SNPs in 136 PEX patients and 89 controls of Indian origin revealed a genetic association between rs2279590 and PEX in Indian population with a p-value of 0.004. The high risk allele "G" at rs2279590 has an effect on clusterin mRNA expression. There was a twofold higher clusterin mRNA level in "GG" genotyped individuals in comparison to "AA" genotyped individuals (p = 0.039). Western blot and immunohistochemistry studies showed an upregulation of Clusterin protein in pseudoexfoliation glaucoma (PXG) affected individuals in both aqueous humor and lens capsules respectively. Together, our results reveal that rs2279590 was found to be associated with PEX in Indian population and the risk allele mediates an allele specific upregulation of the clusterin mRNA. Moreover, upregulation of Clusterin protein in PXG individuals augments further protein deposition.