Pseudoexfoliation and glaucoma in eyes with retinal vein occlusion

Former smoking as a risk factor for visual field progression in exfoliation glaucoma patients in Sweden

PURPOSE

The present study aimed to identify whether former smoking was a risk factor for visual field progression in exfoliation glaucoma patients.

METHODS

Prospective nonrandomised cohort study. The study included patients diagnosed with exfoliation glaucoma. All included patients were followed for three years (± three months) with reliable visual fields. At least five reliable visual fields needed to be included in the study. Exfoliation glaucoma was defined using the European Glaucoma Society Guidelines. The visual fields were tested using the 24-2 test strategy of the Humphrey Field Analyzer. Smoking was assessed through questionnaires. Outcomes: Visual field progression. Three different approaches were used: difference in mean deviation (MD), rate of progression (ROP), and guided progression analysis (GPA).

RESULTS

In total, n = 113 patients were included; among them, n = 57 were smokers. Smoking was a significant predictor for visual field progression in the three models (MD/ROP/GPA) studied (p = 0.01/p = 0.001/p ≤ 0.001), even adjusting for intraocular pressure (IOP). Other predictors were included in the MD model: IOP at diagnosis (p = 0.04) and selective laser trabeculoplasty (SLT) treatment (p = 0.01). Other predictors were in the ROP model: Visual field index (p = 0.005), number of medications (p = 0.001) and SLT treatment (p = 0.001). The number of medications was another predictor in the GPA model (p = 0.002).

CONCLUSIONS

Former smoking induced visual field deterioration in all models studied. Smoking status should be considered when establishing the glaucoma diagnosis. Increased glaucoma care should be provided to former smokers to slow the progression of the disease.

The Importance of Signal Strength Index in Optical Coherence Tomography Angiography: A Study of Eyes with Pseudoexfoliation Syndrome

PURPOSE

To evaluate the effect of the signal strength index (SSI) on a comparison of the vascular and structural OCT measurements between eyes with pseudoexfoliation syndrome (PXF) and healthy controls of Asian-Indian origin.

METHODS

In this cross-sectional study, 33 eyes of 33 PXF patients and 40 healthy eyes of 40 controls underwent OCT and OCT angiography (OCTA). Eyes with intraocular pressure (IOP) >21mmHg, glaucomatous disc changes, or any other ocular pathology were excluded. Peripapillary vessel density (VD) and retinal nerve fiber layer (RNFL) thickness were determined from the optic disc scans. Parafoveal VD and ganglion cell complex (GCC) thickness were measured from the macular scans. These parameters were compared between the groups using mixed effect models after adjusting for clinical confounders such as IOP, as well as SSI of the scans.

RESULTS

The 2 groups were demographically similar. Average RNFL (94µm vs 100µm, p = 0.01) and GCC (91µm vs 95µm, p = 0.03) were thinner in the PXF group compared to controls. The average peripapillary VD appeared lower in the PXF groups compared to controls (58.2% vs 58.8%, p = 0.04), but after adjusting for IOP and SSI, no difference was noted (p = 0.39). After accounting for confounders, parafoveal VD in the PXF group was significantly lower compared to controls (44.3% vs 46.8%, p = 0.008).

CONCLUSION

Peripapillary RNFL thickness, parafoveal GCC thickness and parafoveal VD were decreased in eyes with PXF when compared to controls. VD measurements are associated with the SSI and, therefore, clinicians and researchers evaluating OCTA scans quantitatively must consider the SSI value during analysis and interpretation.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE OF THE STUDY

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparisons of retinal vessel diameter and glaucomatous parameters between both eyes of subjects with clinically unilateral pseudoexfoliation syndrome

Purpose

Pseudoexfoliation syndrome (PEX), the most common identifiable cause of open-angle glaucoma, might affect the retinal hemodynamics. To test this, we compared retinal vessel diameter and glaucoma-related parameters between eyes with pseudoexfoliation material (PE+) and fellow unaffected (PE-) eyes of patients with clinically unilateral PEX.

Methods

The medical records of 30 consecutive Japanese subjects were reviewed retrospectively. The retinal vessel diameters were measured and expressed as the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) using standardized software. During the chart review, we recorded glaucoma-related parameters including intraocular pressure (IOP), visual field mean deviation (MD) value, planimetrically measured vertical cup-to-disc (C/D) ratio, circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and macular inner retinal thickness (mIRT) measured by spectral-domain optical coherence tomography, anterior chamber flare (ACF), corneal endothelial cell density (CECD), and number of antiglaucoma medications.

Results

Compared with PE- eyes, the CRAE, CRVE, MD, cpRNFLT and mIRT, and CECD were significantly lower in PE+ eyes; the IOP, vertical C/D ratio, number of antiglaucoma medications, and ACF were significantly higher in PE+ eyes (P<0.0001 for all comparisons). The CRAE, cpRNFLT, and MD were correlated positively with each other (ρ = 0.456–0.499, P<0.0001–0.0002) and negatively with the IOP (ρ = -0.562- —0.432, P<0.0001–0.0006). The vertical C/D ratio was correlated positively with the IOP (ρ = 0.483, P<0.0001) and negatively with the CRAE, cpRNFLT, and MD (ρ = -0.745–-0.479, P<0.0001–0.0001).

Conclusions

Deposition of PE can cause retinal vessel narrowing in arterioles and venules. The roles and mechanisms of retinal vessel narrowing in glaucoma pathogenesis need clarification.

Central Retinal Vein Occlusion in Younger Swedish Adults: Case Reports and Review of the Literature

Purpose:

To investigate associated systemic diseases, other conditions, visual outcome, ocular complications and treatment in Swedish patients younger than 50 years with central retinal vein occlusion (CRVO) and reviewing the literature.

Methods:

Twenty-two patients with CRVO, younger than 50 years, were examined with full-field electroretinography (ERG) within 3 months after a thrombotic event, or were periodically examined and were observed for at least 6 months. In 18 of these patients, the initial retinal ischemia was studied using the cone b-wave implicit time in the 30 Hz flicker ERG. Fifteen patients also underwent fluorescein angiography. Optical coherence tomography (OCT) was performed in 14 patients. The patients studied were divided into two groups, non-ischemic and ischemic, which were compared. All patients underwent ocular and systemic examination, as well as complete screening for thrombophilic risk factors.

Results:

Of the 22 patients, 15 had non-ischemic type of CRVO and 7 the ischemic type. Patients with non-ischemic CRVO showed significantly improved visual acuity (VA) at the final examination (p=0.006). Patients with ischemic CRVO showed no significant reduction in VA at the final examination (p=0.225). Systemic hypertension (27% in non-ischemic CRVO and 29% in ischemic CRVO) was the most prevalent systemic risk factor for CRVO. The mean central foveal thickness (CFT) decreased significantly from 402.3±136.2 (µm) at the initial examination to 243.8±48.1 (µm) at the final examination in the non-ischemic group (p=0.005). The mean initial CFT was 444.5±186.1 (µm) in the ischemic CRVO group, which decreased to 211.5±20.2 (µm) at the final visit (p=0.068). Pigment dispersion syndrome (PDS)/pigmentary glaucoma (PG), ocular hypertension and dehydration were equally frequent; four patients each (18%) out of 22. The clinical course of 4 younger patients with PDS/PG are described.

Conclusion:

The patients with non-ischemic CRVO showed significantly improved VA and significantly decreased CFT at the final examination. Systemic hypertension was the most prevalent risk factor for CRVO. Younger adults with CRVO also had a high prevalence of PDS/PG, ocular hypertension and dehydration. This study highlights the importance of careful IOP monitoring, and the need to investigate possible PDS/PG and to obtain an accurate history of the patient including alcohol intake and intense exercise.

Central retinal vein occlusion and pseudoexfoliation syndrome

PURPOSE

The purpose of this study was to investigate the existence of pseudoexfoliation syndrome (PXF) as a risk factor for the development of central retinal vein occlusion (CRVO).

METHODS

This was a retrospective, comparative study of the prevalence of pseudoexfoliation in three groups of patients: 48 patients with CRVO, 164 patients with branch retinal vein occlusion (BRVO), and 70 control patients (70 eyes). All patients were phakic and had no previous diagnosis of glaucoma. Patients were matched in terms of age and systemic hypertension. All patients had normal intraocular pressure (IOP) at presentation (defined as less than or equal to 21 mmHg).

RESULTS

In the CRVO group, 14 out of 48 patients were diagnosed as having PXF (29.17%). In the BRVO group, 14 out of 164 patients had PXF (8.5%), and in the control group, six out of 70 patients had PXF (8.6%). Differences of percentage between groups were statistically significant (P<0.001, χ(2) test). When comparing patient subgroup with ischemic CRVO with subgroup with non-ischemic CRVO, we found that in the ischemic CRVO group, 13 out of 27 patients were diagnosed as having PXF (48.15%), and in the non-ischemic CRVO group, one out of 21 patients was diagnosed as having PXF (4.7%; P<0.001, χ(2) test). The relative odds of having CRVO in patients with PXF versus patients without PXF were 4.406 (confidence interval [CI], 2.03-9.54).

CONCLUSION

PXF and CRVO, especially ischemic, are strongly associated in our study. Our results indicate that PXF might be an independent factor for CRVO, as it is related with CRVO independently from glaucoma.

Lack of association of LOXL1 gene variants in Japanese patients with central retinal vein occlusion without clinically detectable pseudoexfoliation material deposits

PURPOSE

A possible association has been reported between exfoliation syndrome (EX) and various ocular and systemic vascular disorders; however, it is unclear if there is an association between EX and central retinal vein occlusion (CRVO). Because latent deposits of exfoliation materials might not be recognized during slit-lamp examination, an ocular biopsy is required to establish a precise diagnosis. We evaluated a possible association between EX and CRVO using lysyl oxidase-like 1 (LOXL1) gene variants as alternative markers for EX.

METHODS

The allelic and genotypic frequencies of three LOXL1 variants (rs1048661, rs3825942, and rs2165241) were determined in 68 consecutive Japanese patients with CRVO [15 with exfoliation syndrome (EX+) and 53 without exfoliation syndrome (EX-)] and 90 control patients with cataract without EX (CT).

RESULTS

The frequencies of the rs1048661 and rs3825942 variants showed borderline difference between the CRVO and CT groups (p = 0.04085 and p = 0.06088, respectively, for allelic frequencies, and p = 0.06838 and p = 0.03482, respectively, for genotypic frequencies). Compared with the CT group, subgroup analysis showed that the CRVO EX+ group had significant differences in the allelic and genotypic frequencies of rs1048661 (p = 0.0006447 and p = 0.0001392, respectively) and had borderline differences in the allelic and genotypic frequencies of rs3825942 (p = 0.03403 and p = 0.07341, respectively), while the CRVO EX- group did not (p = 0.1324-0.6306). Subgroup analysis showed that the frequencies of rs2165241 did not differ between the CRVO and CT groups.

CONCLUSIONS

When the LOXL1 variants were used as disease markers for clinically undetectable EX, there was no association between CRVO and EX. The results suggested that the LOXL1 variants, which are well-established markers for EX, are not likely genetic markers for CRVO in Japanese subjects.

Exfoliation syndrome: a disease with an environmental component

PURPOSE OF REVIEW

Exfoliation syndrome (XFS), the most common cause of secondary open angle glaucoma, is associated with significant ocular morbidity. Recent studies have pointed toward environmental components that may alter the risk of XFS development. This review focuses on the recent studies elucidating the role of environmental factors that play a role in the development of exfoliation syndrome.

RECENT FINDINGS

In XFS, aberrant microfibril formation emanating from the cell-extracellular matrix interface admixes with other macromolecules and is cross-linked by lysyl oxidase like 1 (LOXL1) activity. A common gene variant in the LOXL1 enzyme, an enzyme critical for enhancing the tensile strength of collagen and elastin in extracellular matrices, has been found in approximately 90% of XFS cases. However, approximately 80% of controls also have disease-associated LOXL1 gene variants. These findings point toward other nongenetic factors influencing the development of XFS. Increasing latitude, solar radiation, climatic variables and dietary factors such as high coffee consumption and low dietary folate intake are among the nongenetic factors associated with increased risk of XFS.

SUMMARY

A greater understanding of the environmental components associated with XFS may lead to lifestyle preventive strategies to ameliorate disease burden.

Relation between time spent outdoors and exfoliation glaucoma or exfoliation glaucoma suspect

PURPOSE

To evaluate the relation between time spent outdoors at various life periods and risk of exfoliation glaucoma or exfoliation glaucoma suspect.

DESIGN

Retrospective cohort study in the United States.

METHODS

Participants (49 033 women in the Nurses Health Study and 20 066 men in the Health Professionals Follow-up Study) were 60+ years old, were free of glaucoma and cataract, reported eye examinations, and completed questions about time spent outdoors in direct sunlight at midday at 3 life periods: high school to age 24 years, age 25-35 years, and age 36-59 years (asked in 2006 in women and 2008 in men). Participants were followed biennially with mailed questionnaires from 1980 women/1986 men to 2010. Incident cases (223 women and 38 men) were confirmed with medical records. Cohort-specific multivariable-adjusted rate ratios from Cox proportional hazards models were estimated and pooled with meta-analysis.

RESULTS

Although no association was observed with greater time spent outdoors in the ages of 25-35 or ages 36-59 years, the pooled multivariable-adjusted rate ratios for ≥11 hours per week spent outdoors in high school to age 24 years compared with ≤5 hours per week was 2.00 (95% confidence interval = 1.30, 3.08; P for linear trend = .001). In women, this association was stronger in those who resided in the southern geographic tier in young adulthood (P for interaction = .07).

CONCLUSIONS

Greater time spent outdoors in young adulthood was associated with risk of exfoliation glaucoma or exfoliation glaucoma suspect, supporting an etiologic role of early exposures to climatic factors.

Choroidal thickness changes in patients with pseudoexfoliation syndrome

To evaluate the choroidal thickness using spectral-domain optical coherence tomography (OCT) in patients with pseudoexfoliation syndrome (PXS) and to compare them with healthy controls. This observational comparative study consisted of 35 PXS patients and 35 age- and sex-matched control cases. The control cases had neither systemic nor ocular disease. All 70 patients underwent a complete ophthalmic examination as well as choroidal thickness measurement using a high speed and high resolution SD-OCT device (Topcon 3D OCT-2000, Japan). There was no significant difference with respect to mean refractive error and intraocular pressure measurement between patients with PXS and controls (p = 0.237 and 0.433, respectively). The mean choroidal thickness was found as 206.6 ± 37.6 µm in the PXS group and 215.9 ± 47.3 µm in controls, respectively. The mean choroidal thickness was not significant between the PXS patients and the control cases (p = 0.362). Although PXS patients had lower mean choroidal thickness than controls, our results did not reach any statistical significance.

Influence of diabetes and diabetes type on anatomic and visual outcomes following central rein vein occlusion

PURPOSE

To determine the influence of diabetes and diabetes type on ocular outcomes following central retinal vein occlusion (CRVO).

METHODS

Retrospective chart review of all patients evaluated over a 4-year period in a tertiary diabetes eye care center. Ophthalmic findings were recorded including visual acuity and the presence of retinal neovascularization at presentation, after 3-6 months, and at last follow-up.

RESULTS

The records of 19,648 patients (13,571 diabetic; 6077 nondiabetic) were reviewed. The prevalence of CRVO in diabetic patients (N=72) and nondiabetic patients (N=27) were 0.5 and 0.4%, respectively. Disc neovascularization (21.3 vs 0.0%, P=0.05) and panretinal photocoagulation (PRP) (48.7 vs 21.4%, P=0.01) were more common in diabetic patients compared with nondiabetic patients. Compared with type 2 diabetic patients, retinal neovascularization (28.6 vs 3.7%, P=0.004) and subsequent PRP (78.6 vs 41.9%, P=0.01) were more likely in type 1 patients. Optic nerve head collateral vessels (CVs) were observed less than half as often (21.4 vs 56.5%, P=0.04) in patients with type 1 diabetes. Presence of optic nerve head CVs at baseline was associated with less likelihood of PRP (14.3 vs 46.1%, P=0.03).

CONCLUSIONS

In this cohort, the rates of CRVO in diabetic and nondiabetic patients were similar to previously published population-based studies. Following CRVO, diabetic patients had higher rates of disc neovascularization and were more likely to require subsequent PRP than nondiabetic patients. As compared with CRVO patients with type 2 diabetes, patients with type 1 diabetes and CRVO had worse anatomic outcomes with substantially increased risks of retinal neovascularization and PRP; however, final visual acuity outcomes were similar.

A longitudinal analysis of risk factors associated with central retinal vein occlusion

PURPOSE

To identify risk factors associated with central retinal vein occlusion (CRVO) among a diverse group of patients throughout the United States.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

All beneficiaries aged ≥ 55 years who were continuously enrolled in a managed care network for at least 2 years and who had ≥ 2 visits to an eye care provider from 2001 to 2009.

METHODS

Insurance billing codes were used to identify individuals with a newly diagnosed CRVO. Multivariable Cox regression was performed to determine the factors associated with CRVO development.

MAIN OUTCOME MEASURES

Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of being diagnosed with CRVO.

RESULTS

Of the 494 165 enrollees who met the study inclusion criteria, 1302 (0.26%) were diagnosed with CRVO over 5.4 (± 1.8) years. After adjustment for known confounders, blacks had a 58% increased risk of CRVO compared with whites (HR, 1.58; 95% CI, 1.25-1.99), and women had a 25% decreased risk of CRVO compared with men (HR, 0.75; 95% CI, 0.66-0.85). A diagnosis of stroke increased the hazard of CRVO by 44% (HR, 1.44; 95% CI, 1.23-1.68), and hypercoagulable state was associated with a 145% increased CRVO risk (HR, 2.45; 95% CI, 1.40-4.28). Individuals with end-organ damage from hypertension (HTN) or diabetes mellitus (DM) had a 92% (HR, 1.92; 95% CI, 1.52-2.42) and 53% (HR, 1.53; 95% CI, 1.28-1.84) increased risk of CRVO, respectively, relative to those without these conditions.

CONCLUSIONS

This study confirms that HTN and vascular diseases are important risk factors for CRVO. We also identify black race as being associated with CRVO, which was not well appreciated previously. Furthermore, we show that compared with patients without DM, individuals with end-organ damage from DM have a heightened risk of CRVO, whereas those with uncomplicated DM are not at increased risk of CRVO. This finding may provide a potential explanation for the conflicting reports in the literature on the association between CRVO and DM. Information from analyses such as this can be used to create a risk calculator to identify possible individuals at greatest risk for CRVO.

Demographic and geographic features of exfoliation glaucoma in 2 United States-based prospective cohorts

PURPOSE

To examine prospectively the association between demographic and geographic factors in relation to exfoliation glaucoma (EG) or exfoliation glaucoma suspect (EGS).

DESIGN

Prospective cohort study.

PARTICIPANTS

Seventy-eight thousand nine hundred fifty-five women in the Nurses' Health Study and 41 191 men in the Health Professionals Follow-up Study.

METHODS

Female and male health professionals were followed prospectively from 1980 through 2008 and from 1986 through 2008, respectively. Eligible participants were 40 years of age or older, did not have EG or EGS at baseline, and reported undergoing eye examinations during follow-up. Information regarding demographic features, lifetime geographic residence, and potential confounders was collected. During follow-up, 348 EG or EGS cases were confirmed with medical record review. The relative risk of EG or EGS in each cohort was estimated separately and the results were pooled with meta-analysis.

MAIN OUTCOME MEASURES

Multivariate rate ratios (MVRRs) of EG or EGS and their 95% confidence intervals (CIs).

RESULTS

Exfoliation glaucoma or EGS was strongly age related with subjects 75 years of age or older at 46.22-fold (95% CI, 22.77-93.80) increased risk compared with those between 40 and 55 years of age. Although men were 68% less likely to develop EG or EGS than women (MVRR, 0.32; 95% CI, 0.23-0.46), no predisposition to EG or EGS by ancestry, particularly Scandinavian ancestry, emerged. Compared with a lifetime of living in the northern tier of the continental United States, lifetime residence in the middle geographic tier (MVRR, 0.53; 95% CI, 0.40-0.71) and in the southern geographic tier (MVRR, 0.25; 95% CI, 0.09-0.71) was associated with markedly reduced risks of EG or EGS.

CONCLUSIONS

In this mainly white cohort from the United States, increasing age and female gender were significant risk factors for EG or EGS; however, Scandinavian heritage was not. Living in the middle or southern regions of the United States relative to living in the northern region was associated with a reduced risk of EG or EGS.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Geographic and climatic factors associated with exfoliation syndrome

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Association of exfoliation syndrome and central retinal vein occlusion: an ultrastructural analysis

PURPOSE

To evaluate prospectively the frequency with which exfoliation syndrome (XFS) occurs in patients with central retinal vein occlusion (CRVO) by clinical examination and ultrastructural examination of conjunctival biopsy specimens.

METHODS

Prospective observational case series. Thirty-six eyes of 36 consecutive patients with CRVO were investigated for XFS by slit-lamp examination and conjunctival biopsy when XFS was not clinically visible on examination.

RESULTS

A clinical diagnosis of XFS or a positive biopsy result for exfoliation material (XFM) was present in 22 of the 36 patients (61%; 95% confidence interval 45-75%). Twelve of these 22 patients (54%) had a clinical diagnosis of XFS. Aggregates of XFM were identified ultrastructurally in the biopsy specimens in 10 of 24 patients with no clinical signs of XFS (42%). Patients with and without XFS had similar distribution of age, gender, race and prevalence of systemic disorders. Twelve of the 22 (54%) XFS patients had neither glaucoma nor ocular hypertension prior to the CRVO.

CONCLUSION

In accordance with previous retrospective and histological studies, this prospective, in vivo study suggests that CRVO is commonly associated with XFS.

Electrophysiological evaluation and visual outcome in patients with central retinal vein occlusion, primary open-angle glaucoma and neovascular glaucoma

PURPOSE

To evaluate patients with central retinal vein occlusion (CRVO) and neovascular glaucoma (NVG) using electrophysiology in order to gain better understanding of visual outcome and risk factors, such as previously diagnosed primary open-angle glaucoma (POAG).

METHODS

Eighty-three patients (83 eyes) initially presenting with CRVO and examined with full-field electroretinography (ERG) within 3 months of the thrombotic event were analysed retrospectively regarding treatment, risk factors and visual outcome. In addition, 30 patients initially presenting with NVG caused by CRVO were also investigated regarding risk factors using electrophysiology in order to determine the cause of their visual impairment.

RESULTS

Nineteen (23%) of the 83 patients initially presenting with CRVO had been diagnosed previously with POAG. Ninety-five per cent (18/19) of all the patients with previously diagnosed glaucoma developed ischaemic CRVO. Thirty-four per cent of the patients initially presenting with CRVO (28/83) developed NVG. Sixty-eight per cent (13/19) of the patients with previous glaucoma developed NVG, compared to 23% (15/64) of the patients without previous POAG. In the patients who initially presented with NVG, full-field ERG demonstrated a remaining retinal function of both cones and rods, indicating that the main cause of visual impairment is ischaemia of the ganglion cell layer.

CONCLUSION

Glaucoma is a significant risk factor for developing ischaemic CRVO and subsequent NVG. The presence of POAG in CRVO worsens visual outcome. NVG is associated with preserved photoreceptor function, thus indicating ischaemia of the ganglion cell layer as the primary cause of visual impairment. This emphasizes the importance of prompt treatment of ischaemia and elevated intraocular pressure in these patients.

Directed therapy for exfoliation syndrome

Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix that leads the production of abnormal fibrillar material that leads to elevated intraocular pressure and a relatively severe glaucoma. Exfoliation material is deposited in numerous ocular tissues and extraocular organs. XFS is associated with ocular ischemia, cerebrovascular disease, neurodegenerative disease and cardiovascular disease. Current modalities of treatment include intraocular pressure lowering with topical antihypertensives, laser trabeculoplasty and filtration surgery. The disease paradigm for XFS should be expanded to include directed therapy designed specifically to target the underlying disease process. Potential targets include preventing the formation or promoting the depolymerization of exfoliation material. Novel therapies targeting trabecular meshwork may prove particularly useful in the care of exfoliative glaucoma. The systemic and ocular associations of XFS underscore the need for a comprehensive search for neuroprotective agents in its treatment.

Directed therapy for exfoliation syndrome

Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix that leads the production of abnormal fibrillar material that leads to elevated intraocular pressure and a relatively severe glaucoma. Exfoliation material is deposited in numerous ocular tissues and extraocular organs. XFS is associated with ocular ischemia, cerebrovascular disease, neurodegenerative disease and cardiovascular disease. Current modalities of treatment include intraocular pressure lowering with topical antihypertensives, laser trabeculoplasty and filtration surgery. The disease paradigm for XFS should be expanded to include directed therapy designed specifically to target the underlying disease process. Potential targets include preventing the formation or promoting the depolymerization of exfoliation material. Novel therapies targeting trabecular meshwork may prove particularly useful in the care of exfoliative glaucoma. The systemic and ocular associations of XFS underscore the need for a comprehensive search for neuroprotective agents in its treatment.

Orbital blood flow parameters in unilateral pseudoexfoliation syndrome

PURPOSE

The evaluation of orbital blood flow parameters in patients with unilateral pseudoexfoliation syndrome (XFS) and in age-sex-matched control subjects using color Doppler imaging.

METHODS

This prospective, comparative case series included 33 unilateral XFS patients and 33 age-sex-matched control subjects. Color Doppler imaging was used to evaluate the XFS-affected (Group 1) and -unaffected (Group 2) eyes that were matched with the corresponding side (Groups 3 and 4) of control subjects. All subjects were given a complete ophthalmological examination. A masked radiologist obtained the peak systolic velocity (PSV) and end diastolic velocity (EDV) of ophthalmic (OA), central retinal (CRA), nasal posterior ciliary (NPCA) and temporal posterior ciliary arteries (TPCA) as well as mean velocity of central retinal vein (CRV). Resistivity indices (RI) were calculated.

RESULTS

Analysis of peak systolic and end diastolic velocity (PSV, EDV) and RI between Groups 1-2 and 3-4 did not show any significant difference. Comparing Groups 1-3 (corresponding eyes of pseudoexfoliation-affected and control subjects) and Groups 2-4 (corresponding eyes of pseudoexfoliation-unaffected and control subjects) revealed significantly low values for OA, PSV and EDV in both eyes of the XFS patients. The OA RI value in Group 1 was found to be significantly higher than that in Group 3 with the cut-off value of 0.72.

CONCLUSION

These findings suggest that ophthalmic artery hemodynamic parameters change in both eyes of unilateral XFS patients, illustrating out the systemic nature of the disease. We conclude that XFS decreases OA blood flow velocities and increases vascular resistance through progressive build-up.

The management of exfoliative glaucoma

Exfoliation syndrome (XFS) is an age-related, generalized disorder of the extracellular matrix characterized by the production and progressive accumulation of a fibrillar extracellular material in many ocular tissues and is the most common identifiable cause of open-angle glaucoma worldwide. XFS plays an etiologic role in open-angle glaucoma, angle-closure glaucoma, cataract, and retinal vein occlusion. It is accompanied by an increase in serious complications at the time of cataract extraction, such as zonular dialysis, capsular rupture, and vitreous loss. It is associated systemically with an increasing number of vascular disorders, hearing loss, and Alzheimer's disease. XFS appears to be a disease of elastic tissue microfibrils. The characteristic fibrils, composed of microfibrillar subunits surrounded by an amorphous matrix comprising various glycoconjugates, contain predominantly epitopes of elastic fibers, such as elastin, tropoelastin, amyloid P, vitronectin, and components of elastic microfibrils, such as fibrillin-1, fibulin-2, vitronectin, microfibril-associated glycoprotein (MAGP-1), and latent TGF-beta binding proteins (LTBP-1 and LTBP-2), the proteoglycans syndecan and versican, the extracellular chaperone clusterin, the cross-linking enzyme lysyl oxidase, and other proteins. A recent milestone study showed that two common single nucleotide polymorphisms in the coding region of the lysyl oxidase-like 1 (LOXL1) gene located on chromosome 15 were specifically associated with XFS and XFG. LOXL1 is a member of the lysyl oxidase family of enzymes, which are essential for the formation, stabilization, maintenance, and remodeling of elastic fibers and prevent age-related loss of elasticity of tissues. LOXL1 protein is a major component of exfoliation deposits and appears to play a role in its accumulation and in concomitant elastotic processes in intra- and extraocular tissues of XFS patients. This discovery should open the way to new approaches and directions of therapy for this protein disorder.

Bilateral retinal venous occlusion in pigmentary glaucoma

BACKGROUND

The association of central retinal vein occlusion with primary open angle glaucoma is well known. This communication reports the occurrence of branch retinal vein occlusion and central retinal vein occlusion in a case of pigmentary glaucoma.

METHODS

A 32-year-old man presented with old branch retinal vein occlusion in one eye and resolving central retinal vein occlusion in the other eye. Examination revealed bilateral Krukenberg's spindle and hyperpigmented trabecular meshwork. Intraocular pressure was 30 mmHg OU. Topical antiglaucoma medication was prescribed.

RESULTS

Intraocular pressure was controlled with topical antiglaucoma medication.

CONCLUSION

The present report suggests that intraocular pressure monitoring is important in eyes even with branch retinal vein occlusion. Pigment dispersion may be the underlying cause for bilateral retinal vein occlusion, especially in young patients.

Intraocular pressure abnormalities associated with central and hemicentral retinal vein occlusion

OBJECTIVE

To evaluate the prevalence of ocular hypertension (OHT) and glaucoma in patients with central retinal vein occlusion (CRVO) and hemi-CRVO (HCRVO) and of the fall in intraocular pressure (IOP) secondary to CRVO/HCRVO.

DESIGN

Nonrandomized comparative case series.

PARTICIPANTS AND METHODS

We investigated 674 consecutive patients who were initially seen with unilateral CRVO (n = 548) and HCRVO (n = 126) at their onset, with a normal fellow eye. The fellow uninvolved eye in each patient acted as a control. Central retinal vein occlusion and HCRVO were categorized into nonischemic and ischemic. At all visits, patients had a detailed ocular history, as well as a thorough bilateral ocular evaluation, including IOP recording with a Goldmann applanation tonometer; when the diagnosis of OHT or glaucoma was initially uncertain, the 24-hour diurnal IOP was recorded. The observed prevalence rates of OHT and glaucoma among patients with CRVO and HCRVO were compared with those in the general population.

MAIN OUTCOME MEASURES

The prevalence of OHT and glaucoma, and of ocular hypotension secondary to CRVO/HCRVO.

RESULTS

The overall prevalence of glaucoma was 9.9% and of OHT 16.2%. The prevalence of glaucoma/OHT was found to be significantly (P<0.0001) higher in patients with CRVO and HCRVO than in the general population. There was no significant difference in the proportion of patients with glaucoma/OHT among the various types of CRVO/HCRVO (P = 0.156). Forty-eight percent of all patients had lower IOP (>/==" BORDER="0">2 mmHg) in the CRVO/HCRVO eye than in the fellow (uninvolved) eye at their initial evaluation. The prevalence of ocular hypotension was significantly (P<0.0001) higher in patients with glaucoma/OHT not on ocular hypotensive therapy than in patients without glaucoma. Among the patients without glaucoma, the prevalence of ocular hypotension differed significantly among the various types of CRVO/HCRVO (P = 0.007).

CONCLUSIONS

Central retinal vein occlusion and HCRVO have a significant association with glaucoma and OHT and with a subsequent fall in IOP in the involved eye. Few patients with CRVO/HCRVO have high IOP in the involved eye, although many of them do have it in the fellow uninvolved eye. It is important to exclude glaucoma/OHT in the fellow eye of any patient with CRVO/HCRVO; if present, elevated IOP should be treated to reduce the risk of that eye developing (1) CRVO/HCRVO and (2) glaucomatous damage. There may be no benefit to prescribing IOP-lowering drops for involved eyes whose IOP is already normal.

Central retinal vein occlusion in pseudoexfoliation of the lens capsule

In surveying an extensive group of patients with unilateral pseudoexfoliation of the lens capsule certain interesting points emerged, particularly on the incidence of central retinal vein occlusion in this condition,and perhaps in glaucoma also. A total of 284 patients with unilateral pseudo-exfoliation of the lens capsule were examined clinically after an ophthalmic and general history were taken. Mean intraocular pressure (IOP) was 30.9 mmHg in the affected eye and 18.1 mmHg in the unaffected eye. Central retinal vein occlusion occurred in 10 affected eyes but no unaffected eyes and always in affected eyes with a rise in IOP. Average IOP in the affected eye with central retinal vein occlusion was 37.5 mmHg (range 26-54 mmHg);in the unaffected fellow eye it was 18.0 mmHg (range 11-28 mmHg). Although the process involved in producing pseudo-exfoliation of the lens capsule may contribute to the precipitation of central retinal vein occlusion, these findings suggest the rise in IOP is the more important cause. This may also be so in other forms of glaucoma.