Pseudoexfoliation syndrome in eyes with ischemic central retinal vein occlusion. A histopathologic and electron microscopic study

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Platelet Proteome Reveals Novel Targets for Hypercoagulation in Pseudoexfoliation Syndrome

Pseudoexfoliation syndrome (PEX) is characterized by the accumulation of abnormal extracellular matrix material in ocular and non-ocular tissues, including blood vessel walls. Clot-forming dysfunction might be responsible for venous thrombosis in PEX. We investigated global coagulation, the proteome, and functions of platelets in PEX patients and aimed to determine prognostic biomarkers for thrombosis risk in PEX. Peripheral blood was collected from PEX and retinal vein occlusion (RVO) patients, and age-sex matched controls. Viscoelastic hemostasis was evaluated by rotational thromboelastometry (ROTEM). Platelet markers (CD41, CD42, CD61, and CD62p) and endothelial markers (P-selectin, E-selectin, and von Willebrand factor) were investigated by flow cytometry and ELISA, respectively. The platelet proteome was analyzed by 2D fluorescence difference gel electrophoresis followed by mass spectrometry. Clot formation time (CFT) is significantly reduced in PEX patients compared to the controls (p < 0.05). P-selectin levels were higher in PEX patients than in controls (p < 0.05); E-selectin and von Willebrand factor remained unchanged. The monitorization of CFT by ROTEM, and soluble P-selectin, may help assess thrombotic risk in PEX patients. Proteomic analysis revealed differential expression of Profilin-1 in platelets. Profilin-1 regulates the stability of actin-cytoskeleton and may contribute to impaired platelet hemostatic functions. Increased P-selectin levels together with impaired coagulation dynamics might be responsible for the thrombotic events in PEX disease.

Visual Field Progression After Glaucoma Surgery in Pseudoexfoliation versus Primary Glaucoma

Purpose

To compare visual field progression in severity-matched pseudoexfoliation glaucoma (XFG) and primary glaucoma after intraocular pressure (IOP) reduction by filtering surgery.

Methods

Patients with XFG (n=32), primary open-angle glaucoma (POAG, n=33) or primary angle closure glaucoma (PACG, n=28) that underwent routine cataract and glaucoma filtering surgery by the same surgeon (APR) between May 2017 and September 2021, were included for this prospective study. Rate of progression (ROP) was determined using guided progression analysis and compared between XFG and primary glaucoma. Multivariate regression was done to analyse the factors responsible for progression in each group.

Results

Visual field progression after surgery was noted in 48 eyes (n=11 XFG, 18 POAG and 19 PACG eyes) at a mean follow-up of 10±5.6 months after surgery with RVI seen in 18 of 48 eyes. The final IOP (p=0.8) and mean ROP (p=0.09) were not significantly different between XFG and primary glaucoma. The XFG eyes had a greater number of eyes (36%) showing an ROP worse than -5dB/yr, with 45% of eyes showing an IOP spike >5mm Hg, and a higher mean IOP spike between visits. The ROP in eyes with RVO and >5mm Hg IOP spikes was greater in XFG than in POAG or PACG. In the multivariate analysis, higher IOP fluctuations >5mm Hg, and associated retinal vein occlusions (RVO) were significant factors for visual progression greater than -5dB/year (R2=53.5%) in POAG and XFG eyes. Age, gender, baseline MD, and number of medications before surgery or at final follow-up did not influence visual progression rates in either group.

Conclusion

A higher IOP fluctuation >5mm Hg and associated RVO were the significant factors predicting visual field progression after filtering surgery in XFG and POAG eyes. Control of both IOP-dependent and -independent mechanisms of VF progression is therefore essential in these eyes.

Outcomes of Phaco-viscocanalostomy in Primary Open Angle Glaucoma versus Pseudoexfoliation Glaucoma

Purpose

Viscocanalostomy represents an alternative to standard penetrating glaucoma surgery. The aim of this study is to compare the outcomes of combined phacoemulsification and viscocanalostomy in eyes with primary open-angle glaucoma (POAG) versus eyes with pseudoexfoliation glaucoma (PEXG).

Methods

In this prospective non-randomized comparative study, eyes with cataract and POAG or PEXG were enrolled. Pre- and postoperative data including best corrected visual acuity (BCVA), intraocular pressure (IOP), and the number of antiglaucoma medications administered were recorded at each visit. All patients underwent phacoviscocanalostomy. Complete success was defined as the IOP of 21 mmHg or less without the administration of medication while a qualified success reported the same IOP parameters either with or without the administration of medication.

Results

Fifty-four eyes with POAG and fifty-four with PEXG underwent phacoviscocanalostomy. The mean follow-up time was 23.36 ± 8.8 months (range, 6-40 months). The mean postoperative IOP reduced significantly in both groups, although the mean IOP reduction was significantly greater in PEXG eyes (14.7 ± 8.9 vs 10.1 ± 7.7 mmHg) (P = 0.05). At the final follow-up visit, the mean postoperative IOP was 14.1 ± 2.1 and 16.6 ± 3.5 mmHg in the PEXG and POAG eyes, respectively (P = 0.001). A complete success rate of 88.9% and 75.9% was achieved in PEXG and POAG eyes, respectively (P = 0.07). The qualified success rate was 100% in the PEXG and 85.2% in POAG groups (P = 0.03).

Conclusion

Phacoviscocanalostomy achieved significant IOP reduction and visual improvement in both POAG and PEXG patients. Our results indicated that in terms of IOP reduction, this procedure was more effective in treating PEXG.

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 vascularity index in pseudoexfoliative glaucoma

PURPOSE

To evaluate choroidal vascular involvement in pseudoexfoliative glaucoma (PEXG) by applying the choroidal vascularity index (CVI) to optic coherence tomography (OCT) images.

METHODS

Seventy-eight eyes from 40 subjects were included the study. Group 1 included healthy eyes (n = 20), group 2 eyes with PEX (n = 16), and group 3 eyes with PEXG (n = 42). OCT imaging of macular and peripapillary regions and retinal nerve fiber layer (RNFL) analyses were performed. CVI was calculated using ImageJ software.

RESULTS

The mean age was 64.89 ± 5.8, 71.2 ± 7.8, and 68.24 ± 7.4 years in groups 1, 2, and 3, respectively (p = 0.046). There were no significant differences between the groups in terms of sex (p = 0.777). In macula, mean CVI rates were 66.97 ± 1.9%, 64.23 ± 1.2%, and 64.63 ± 1.6%, and in the peripapillary areas, mean CVI rates were 67.04 ± 1.5%, 65.20 ± 1.5%, and 64.14 ± 2.1% in groups 1, 2, and 3, respectively (group 1 vs. group 2 and 3, p = 0.000; group 2 vs. group 3, p > 0.05). The decrease in average RNFL thickness was statistically significant in group 3 compared to groups 1 and 2.

CONCLUSION

CVI could be used to assess choroidal vascular changes in ocular diseases. CVI was found to be reduced in PEX and PEXG, indicating an ocular vascular involvement in pseudoexfoliative process.

Nasal mucociliary clearance and hearing loss in pseudoexfoliation syndrome

PURPOSE

To evaluate nasal mucociliary clearance (NMC) and hearing loss in patients with pseudoexfoliation (PEX) syndrome.

METHODS

The study included 36 patients with PEX syndrome as the study group, and 39 healthy individuals as the control group. The duration of NMC was measured using the saccharine test. Audiometry was applied at 250, 500, 1000, 2000, 4000, 6000 and 8000 Hz frequencies to determine hearing thresholds and prevalence of hearing loss.

RESULTS

No statistically significant difference was determined between the groups in respect of age and gender (p = 0.23 and p = 0.36, respectively). In the saccharine test, the mean NMC time was 18.41 ± 8.53 min for the study group and 11.69 ± 4.96 min for the control group. The mean NMC time of study group was significantly longer than that of the controls (p < 0.001). In the comparisons of the two groups in terms of the prevalence of hearing loss, no statistically significant difference was found at any of the evaluated frequencies (p > 0.05, for all). There was also no statically significant difference between groups in relation to hearing thresholds at these frequencies (p > 0.05, for all).

CONCLUSION

The NMC time was significantly prolonged in patients with PEX syndrome. This result indicates that nasal mucosa cilia, which have similar elastic and mobile structures as the iris, are damaged in PEX syndrome, which is an infiltrative disease increasing the rigidity of affected tissues. In upper respiratory tract infections of unknown cause, PEX syndrome should be considered among the etiological factors. In this study, no significant relationship was detected between PEX and hearing loss.

Cohort Study of Nonmelanoma Skin Cancer and the Risk of Exfoliation Glaucoma

PRECIS

In a cohort study of 120,307 participants with 25+ years of follow-up, a history of nonmelanoma skin cancer (NMSC) was associated with a 40% higher exfoliation glaucoma (XFG) risk.

PURPOSE

The purpose of this study was to evaluate the relationship between NMSC (a marker of ultraviolet radiation exposure) and XFG.

METHODS

We performed a cohort study of US women (n=79,102; 1980-2014) and men (n=41,205; 1986-2014), aged 40+ years and at risk for glaucoma who reported eye examinations. From 1984 (women)/1988 (men), we asked about basal cell carcinoma or squamous cell carcinoma history separately; in prior years, we asked about any NMSC history in a single question. Squamous cell carcinoma was confirmed with histopathology reports while basal cell carcinoma and any early (<1984/<1988) NMSC history was self-reported. Incident XFG cases (362 women and 83 men) were confirmed with medical records. Using pooled data, we estimated multivariable-adjusted relative risks [MVRRs; 95% confidence intervals (CIs)] with Cox proportional hazards models that were stratified by age (in mo), 2-year time period at risk and average lifetime residential latitude.

RESULTS

In multivariable-adjusted analyses, we observed a 40% higher XFG risk with any NMSC history (MVRR=1.40; 95% CI=1.08-1.82); the association was observed even with 4 and 8-year lags in NMSC history. Also, the NMSC association was stronger in younger (below 65 y; MVRR=2.56; 95% CI=1.62-4.05) versus older participants (65 y and above; MVRR=1.25; 95% CI=0.94-1.66; P for interaction=0.01) and those living in the northern latitudes (≥42°N; MVRR=1.92; 95% CI=1.28-2.88) versus more southern latitudes (<42°N; MVRR=1.19; 95% CI=0.86-1.66; P for interaction=0.04).

CONCLUSION

NMSC was associated with higher XFG risk, particularly among younger participants and those living in the Northern US.

Histopathology of Exfoliation Syndrome

Exfoliation syndrome (XFS) is characterized by light and electron microscopy by age-dependent gradual accumulation of whitish material of largely unknown composition and origin along both the anterior and posterior chambers and widely within the iris stroma. These deposits can be fairly specifically labeled with selected antibodies and lectins. Immunohistochemistry shows that intraocular exfoliation deposits share antigens with the microfibrillar elastic fiber system and several basement membrane components, including carbohydrate epitopes on glycosaminoglycans, proteoglycans, and cell adhesion molecules. The earliest histopathologic manifestation of XFS seems to be the deposition of characteristic fibers in various extraocular and anterior segment tissues, as observed by electron microscopy, and perivascular deposition of material within the iris stroma, which is antigenically typical of that found in classic intraocular exfoliation deposits. These findings precede the clinical diagnosis of XFS and likewise can be detected in the seemingly uninvolved fellow eyes of patients with clinically unilateral XFS. Indeed, histopathologic examination of capsulotomy, iridectomy, and trabeculectomy specimens can lead to a clinically unexpected diagnosis of XFS. Exfoliation fibers are additionally found widely distributed in extraocular connective tissues and visceral organs, but the matrix of these fibers seems to differ from that of intraocular deposits. In addition to this histopathologic discrepancy, both the frequent occurrence of clinically unilateral, histopathologically highly asymmetric exfoliation deposits, and the relationship between the early iris vasculopathy that not infrequently may be observed histopathologically for years before classic widespread exfoliation deposits appear along the anterior and posterior chambers remain to be resolved.

Retinal and Choroidal Vascular Changes in Eyes with Pseudoexfoliation Syndrome: A Comparative Study Using Optical Coherence Tomography Angiography

Background:

Optical coherence tomography angiography allows a detailed evaluation of retinal and choroidal microvascular structures without the need for a contrast agent. Pseudoexfoliation syndrome is a condition that leads to anatomical and functional losses due to accumulation of degraded abnormal fibrillar material in the intraocular and extraocular tissues. Histopathological studies have shown that the accumulation of Pseudoexfoliation syndrome material in the vascular structures may play a role in different ocular pathologies such as retinal vein occlusion, iris hypoperfusion, anterior segment hypoxia, retinal arterial occlusion, and neovascular glaucoma.

Aims:

To evaluate and compare flow and vascular density in the retina and choroid in eyes with Pseudoexfoliation syndrome, fellow eyes without Pseudoexfoliation syndrome, and healthy eyes using optical coherence tomography angiography.

Study Design:

Case control study.

Methods:

The study included 35 eyes with Pseudoexfoliation syndrome of 35 Pseudoexfoliation syndrome patients, 32 fellow eyes without Pseudoexfoliation syndrome of 32 unilateral Pseudoexfoliation syndrome patients, and 35 eyes of healthy control subjects. Flow area and vascular density in the superficial capillary plexus and deep capillary plexus were measured by optical coherence tomography angiography as three separate parameters: total, parafoveal, and foveal. Choroidal thickness and foveal avascular zone area were measured for each patient.

Results:

There were significant differences between the Pseudoexfoliation syndrome eyes and control eyes in total, parafoveal, and foveal flow and vascular density in the superficial capillary plexus (p<0.05 for all), while there were no significant differences between these groups in any of the flow or vascular density values in the deep capillary plexus (p>0.05). None of the superficial capillary plexus and deep capillary plexus flow and vascular density values showed significant differences between Pseudoexfoliation syndrome eyes and non-Pseudoexfoliation syndrome fellow eyes or between the non-Pseudoexfoliation syndrome fellow eyes and control eyes (p>0.05). Choroidal thickness was significantly lower in Pseudoexfoliation syndrome eyes compared to control eyes. Foveal avascular zone area was significantly enlarged in Pseudoexfoliation syndrome eyes compared to control eyes in both the superficial and deep layers (p<0.05).

Conclusion:

Pseudoexfoliation syndrome eyes exhibit significant damage to the retinal and choroidal vascular structures.

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.

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.

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.

Ophthalmic artery blood flow parameters in pseudoexfoliation glaucoma

PURPOSE

To investigate orbital flow parameters of ophthalmic artery (OA) in patients with pseudoexfoliation glaucoma (XFG) by ultrasonography.

METHODS

This case-control study included 38 patients with XFG and 32 healthy control subjects. Color Doppler imaging was performed to evaluate orbital flow parameters of OA. Receiver operating characteristic analyses were performed to define the best cutoff value.

RESULTS

In the XFG group, decreased peak systolic velocity (p = 0.114), end diastolic velocity (p = 0.002), and increased resistivity index (RI) (p&lt;0.001) at OA compared to healthy controls were observed. A cutoff value 0.72 for OA RI was found to have a sensitivity of 66% and specificity of 94%.

CONCLUSIONS

The results support the findings of increased vascular resistance in OA XFG. High sensitivity and specificity obtained for OA RI may be useful in evaluation of future therapeutic vascular agents.

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.

Evaluation of choroidal thickness using enhanced depth imaging by spectral-domain optical coherence tomography in patients with pseudoexfoliation syndrome

PURPOSE

To investigate the choroidal thickness using optical coherence tomography in the eyes of patients with unilateral and bilateral pseudoexfoliation syndrome and to compare them with healthy controls.

METHODS

We studied four groups: (1) affected eyes from 30 patients with unilateral PEX syndrome affecting the right eye of 17 patients and the left eye of 13 patients; (2) clinically unaffected eyes of 30 patients with unilateral PEX syndrome; (3) the eyes of 30 patients with bilateral PEX syndrome; and (4) the eyes of 30 normal healthy subjects. Choroidal thickness was evaluated using high-speed, high-resolution enhanced depth imaging by spectral-domain optical coherence tomography. Optical coherence tomography features were compared in all groups using the statistical package SPSS v 15.0.

RESULTS

The mean subfoveal choroidal thicknesses were 237.35±58.01 μm in group 1; 330.75±47.84 μm in group 2; 206.3±86.75 μm in group 3; and 311.8±51.42 μm in group 4. Significant differences in the mean subfoveal choroidal thickness were found between groups 1 and 2 (P<0.001), groups 1 and 4 (P=0.004), groups 2 and 3 (P<0.001), and groups 3 and 4 (P<0.001).

CONCLUSION

In this study, it was observed that clinically affected eyes of patients with PEX syndrome have significantly thinner choroids compared with the clinically unaffected eyes of patients with unilateral PEX syndrome and eyes of healthy controls.

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.

Pseudoexfoliation syndrome and cardiovascular diseases

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

Clusterin and complement activation in exfoliation glaucoma

PURPOSE

The study was done to better understand the biological significance of clusterin co-localization with the exfoliation deposits (XF deposits), and provide insight into a pathogenic mechanism involving activation of the complement system and its pro-inflammatory consequences in patients with exfoliation glaucoma.

METHODS

Exfoliation lens deposits were analyzed by high resolution atomic force microscopy imaging and confocal immunofluorescence. Levels of clusterin and vitronectin, as well as of the complement activation products C3a and soluble C5b-9, were assessed via ELISA.

RESULTS

Atomic-force microscopy examination of lenses with exfoliation syndrome (XFS) revealed a dense fibrillar network on the anterior, aqueous-bathed surface of the lens, while the epithelial side displayed no discernible structural features at the same resolution. Clusterin colocalized with XF deposits, demonstrating integral association with the fibrils. Levels of activation-derived complement components C3a and soluble C5b-9, as well as the complement inhibitors clusterin and vitronectin, were found significantly elevated (1.7-fold, P < 0.05; 4.1-fold, P < 0.05; 1.8-fold, P < 0.01; and 3.0-fold, P < 0.01, respectively) in aqueous humor from glaucoma patients with XFS compared to non-XFS glaucoma controls.

CONCLUSIONS

The data provide compelling evidence for the activation of the complement system in XFS, highlighting the generation of subproducts with potent proinflammatory activity, which are capable of triggering and chronically maintaining levels of subclinical inflammation, suggesting novel targets for therapeutic intervention. The colocalization of clusterin in exfoliation fibrils suggests a failed attempt to prevent tissue accumulation of protein aggregates, as seen in other protein folding disorders, likely due to the abnormal high levels of misfolded proteins overwhelming its chaperone capacity.

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.

Differences between Goldmann Applanation Tonometry and Dynamic Contour Tonometry in pseudoexfoliation syndrome

PURPOSE

To evaluate differences between Goldmann Applanation Tonometry (GAT) and Dynamic Controur Tonometry (DCT) in eyes with pseudoexfoliation syndrome (PEX).

METHODS

Thirty-eight patients (38 eyes) with PEX in both eyes (pseudoexfoliative group, PG) as well as 19 patients (19 eyes) without PEX in either eye (control group, CG), were included. All eyes were phakic. GAT, DCT, the central corneal thickness (CCT) and the axial length of the eyeball (AL) were measured and the difference between GAT and DCT (dIOP) was calculated. Differences in dIOP between CG and PG and correlations of dIOP with CCT and AL were examined.

RESULTS

dIOP was significantly (P = 0.02) higher in PG (mean value 3.69 mmHg), compared with CG (mean value 2.15 mmHg). In PG (but not in CG), dIOP was also significantly correlated with AL but not with CCT.

CONCLUSION

The fact that dIOP was significantly higher in PG than in CG implies that PEX may affect ocular biomechanical properties. The significant association of dIOP with AL but not with CCT is in agreement with previous reports and complies with the fact that pseudoexfoliative material is not deposited in corneal stroma.

[Ocular pseudoexfoliation syndrome]

INTRODUCTION

This study was aimed at providing an update on most recent developments regarding ocular and systemic manifestations and complications, clinical diagnosis and management, and molecular patophysiology of pseudoexfoliation syndrome.

METHOD

Review of recent literature and own clinical and laboratory studies.

RESULTS

Pseudoexfoliation syndrome is an age-related disease in which abnormal fibrillar extracellular material is produced and accumulated in many ocular tissues. Recent progress and advances have led to improvements in clinical management by understanding the effects of the pseudoexfoliation process on the ocular tissues, by refining diagnostic criteria and applying new treatment regimes, and by developing preventive strategies to reduce surgical complications. Increasing evidence of systemic associations of cardiovascular, cerebrovascular, abdominal aorta aneurysm can provide better understanding and management of this condition, and new therapeutic goal. The current pathogenesis concept describes psuedoexfoliation syndrome as an elastic microfibrillopathy involving transforming growth factor-beta, matrix metalloproteinase oxidative stress.

CONCLUSION

Despite extensive research, the exact chemical composition of exfoliation material remains unknown. The presence of pseudoexfoliation should alert the physician to the increased risks of intraocular surgery, most commonly zonular dehiscence, capsular rupture, and vitreous loss during cataract extraction. Its associated clinical signs are important in the detection and management of glaucoma.

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.

Central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy associated with an overlap syndrome: a case report

Introduction

An "overlap syndrome" is defined as the sequential appearance over time of two or more risk factors for glaucomatous damage. The appearance of a new risk factor can alter the course and prognosis of previously stable disease. Exfoliation syndrome is a leading cause of glaucoma and is associated with vascular disease. We report a case of central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy in a patient with overlap syndrome.

Case presentation

An 87-year-old woman with longstanding stable primary open-angle glaucoma developed bilateral exfoliation syndrome, after which her intraocular pressure became uncontrolled and her glaucomatous damage progressed rapidly. She also developed ischemic arterial events in both eyes.

Conclusion

The case presented here shows that overlap syndromes can lead to rapid, irreversible vision impairment. To the best of our knowledge, this is the first reported case of central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy in a patient with overlap syndrome.

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.

Depression and anxiety in patients with pseudoexfoliative glaucoma

OBJECTIVE

This study aimed to determine whether patients with pseudoexfoliative glaucoma (PXG), associated with vascular disorders, have more depressive and anxiety symptoms than patients with primary open-angle glaucoma (POAG) and controls without glaucoma. The vascular depression model was tested in this study.

METHOD

The sample consisted of 41 PXG patients, 32 POAG patients and 40 controls. Each subject was diagnosed as having PXG or POAG or chosen as a control patient by an ophthalmologist and then evaluated by a psychiatrist. The Structured Clinical Interview for DSM-IV, Turkish version; Hamilton Depression Rating Scale (HDRS); Hamilton Anxiety Rating Scale (HARS); Mini Mental State Examination; and Montgomery-Asberg Depression Rating Scale (MADRS) were administered to all subjects.

RESULTS

The HDRS and MADRS scores of the PXG patients were significantly higher than those of the POAG and the control group (chi(2)=9.858, p=.007 and chi(2)=11.618, p=.003, respectively). The HARS scores did not show a significant difference between the patients with PXG or POAG and the control subjects (chi(2)=1.615, p=.446). In each of the three groups, there was no correlation between the HDRS, HARS or MADRS scores and any of the following parameters: duration of glaucoma, medical treatment, visual acuity, intraocular pressure, perimetric stage, cup-disc ratio and number of glaucoma operations (p>.05).

CONCLUSION

A relationship between PXG and severity of depressive symptoms was shown by our data. However, no significant difference could be found between the anxiety levels of the three groups.

Magnetic resonance imaging of the brain in patients with pseudoexfoliation syndrome and glaucoma

PURPOSE

To evaluate ischemic changes in brain magnetic resonance images in patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) and compare them with age- and sex-matched control subjects.

METHODS

This case-control study involved 16 consecutive patients with PXS, 21 patients with PXG and 18 healthy age- and sex-matched control subjects. Each subject underwent a comprehensive ophthalmological examination. In all participants, an axial T(1)-, T(2)- and proton-density-weighted and coronal cerebral 1.5-tesla magnetic resonance imaging (MRI) scan was made. White matter hyperintensities (WMH) were considered present if these were hyperintense on both proton-density- and T(2)-weighted images and not hypointense on T(1)-weighted images. White matter lesions were classified into two parts as the subcortical and periventricular regions. We used a validated rating scale of subcortical WMH: 0 = absent, 1 = punctuate foci, 2 = beginning confluence of foci and 3 = large confluent areas. Periventricular white matter lesions were classified on a scale of 0 (no white matter lesions), 1 (pencil-thin periventricular lining), 2 (thick lining) or 3 (large confluent white matter lesions).

RESULTS

The proportions of persons with WMH were 93.7% for patients with PXS, 95.2% for patients with PXG and 55.5% for control subjects. The numbers of white matter lesions in patients with PXS and PXG were significantly greater than in the control subjects (p < 0.05). White matter lesions at subcortical locations in patients with PXG were significantly more frequent than in the control subjects (80.9 vs. 33.3%; p < 0.05). The proportion of patients with subcortical WMH was 56.2% in PXS; no significant difference was found in subcortical WMH between PXS and controls. The proportions of patients with periventricular WMH were 93% in PXS, 90.4% in PXG and 44.4% in controls. White matter lesions at periventricular locations in patients with PXG and PXS were significantly more frequent than in the control subjects (p < 0.05). The difference between the pseudoexfoliation groups and controls with regard to the size of periventricular and subcortical white matter lesions was statically significant (p < 0.05). When patients with PXS were compared with PXG patients, there was no statistically significant difference in the number, size and scale of white matter lesions.

CONCLUSION

We found a significantly higher prevalence of MRI-defined WMH in patients with a clinical diagnosis of pseudoexfoliation with or without glaucoma versus control subjects. We think that the findings in this study may shed light on a possible link between ischemic brain lesions and pseudoexfoliation, which is not related with the presence of glaucomatous optic neuropathy. Further investigations are required to resolve the underlying associations.

Serum homocysteine, vitamin B 12 and folic acid levels in different types of glaucoma

Background

This study was performed to compare levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with primary open-angle glaucoma (POAG), pseudoexfoliative glaucoma (PEXG), normotensive glaucoma (NTG) and healthy controls.

Methods

Twentyfive patients with POAG, 24 with PEXG, and 18 with NTG, along with 19 control healthy subjects were included this prospective study. Levels of serum Hcy were measured using immunoassay, and those of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay.

Results

The mean Hcy concentration in the PEXG group was significantly higher (P < 0.001) as compared to the other groups. There were no significant differences with respect to the mean Hcy concentrations among other groups (P > 0.05). There were no statistical differences in serum vitamin B12 levels among POAG, PEXG, NTG and control subjects (P > 0.05).

The mean serum folic acid level was significantly lower in the subjects with PEXG (P < 0.009). However, the mean folic acid concentrations among the other groups did not differ significantly (P > 0.05).

Conclusion

Elevated levels of Hcy in PEXG may explain the role of endothelial dysfunction among patients with PEXG.

Exfoliation syndrome in Nordic countries: a comparative histopathological study of Danish and Finnish eyes with absolute glaucoma and uveal melanoma

PURPOSE

To compare the frequency of exfoliation syndrome (EXS) in Denmark and Finland in eyes enucleated for absolute glaucoma and uveal melanoma and to correlate these results to reported clinical prevalence rates.

METHODS

The material consisted of 304 and 39 eyes consecutively removed because of absolute glaucoma and of 240 and 149 eyes enucleated because of uveal melanoma in Denmark and Finland, respectively. Histological sections of all eyes were stained with haematoxylin-eosin and periodic acid-Schiff and examined under a light microscope for EXS. Diagnosis of EXS was made by the consensus of the investigators.

RESULTS

In absolute glaucoma eyes, EXS was observed in 12 out of 304 eyes (3.9%, 95% CI 2.1-6.8) in Denmark, and in 16 out of 39 eyes (41%, 95% CI 26-58) in Finland (p < 0.0001). In the melanoma eyes, EXS was noted in two out of 240 eyes (0.8%, 95% CI 0.1-3.0) in Denmark and in nine out of 149 eyes (6.0%, 95% CI 2.8-11) (p < 0.0037) in Finland.

CONCLUSIONS

The frequency of EXS was significantly higher in eyes removed for absolute glaucoma and malignant melanoma in Finland than in Denmark. This supports the clinical impression that EXS is rare in Denmark compared to other Nordic countries.

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.

Plasma and aqueous humour levels of homocysteine in exfoliation syndrome

BACKGROUND

Recent studies have suggested that the relationship between elevated plasma homocysteine (Hcy) and increased risk of vascular disease holds also for certain diseases of the eye with vascular aetiology. Elevated plasma Hcy levels have been noted among patients with exfoliation syndrome (XFS). The purpose of this study was to establish whether subjects with XFS have higher plasma and aqueous humour Hcy levels values than non-XFS subjects, particularly in relation to vitamin B status.

METHODS

Using a cross-sectional study design, 36 subjects with XFS and 36 non-XFS subjects with intraocular pressure (IOP) lower than 23 mmHg, matched by age and gender, were first selected. The participant exclusion criteria included parameters known to alter Hcy metabolism. In the XFS group, 11 subjects had a concurrent diagnosis of exfoliative glaucoma (XFG). Fasting plasma and aqueous humour Hcy samples were collected, along with erythrocyte folate (E-Fol) and serum vitamin B6 and B12 samples. The Hcy samples were analysed using a fluorescence polarization immunoassay method.

RESULTS

Plasma Hcy level was significantly higher (P=0.020, after Bonferroni correction for multiple testing) in the XFS group than in the controls. The Hcy concentrations in the aqueous humour did not differ statistically between the two groups. Plasma and aqueous humour Hcy concentrations were not statistically significantly correlated within the groups of exfoliation-positive and -negative subjects. E-Fol, and serum vitamin B6 and B 12 levels did not differ statistically between the XFS group and the control group.

CONCLUSIONS

The finding that subjects with XFS are more prone to elevated plasma Hcy emphasizes exfoliation as a clinical sign and a marker of thromboembolic vasculopathies induced by hyperhomocysteinaemia.

Pseudoexfoliation syndrome: pathological manifestations of relevance to intraocular surgery

Pseudoexfoliation syndrome (PEX) is a common ocular condition often associated with the need for intraocular surgery. Although results of cataract and glaucoma filtering surgery in eyes with PEX in the early stages of the disease may be comparable to those in eyes without PEX, in the later stages morbidity is significantly increased due to periocular surgical complications and the outcome is worse. Surgical and postoperative difficulties are often multifactorial and are directly related to the pathological changes of PEX on intraocular structures. Recent years have seen a large increase in the understanding of the effects of PEX on the various ocular tissues. Although the visible areas of the anterior capsule are most obviously involved, this is only a small part of the picture and of least significance. Biomicroscopically invisible changes of the zonules and their attachments are of greatest consequence. There is also distinct, often active, involvement of almost all tissues of the anterior segment of the eye, many of which have important implications for the anterior segment surgeon including iridopathy, iris vasculopathy (including persistent breakdown of the blood-aqueous barrier and anterior segment hypoxia), ciliary body involvement and keratopathy. Trabecular dysfunction is evident by the deposition of PEX material derived from both in situ and extra-trabecular production as well as protein and melanin deposition. These changes should be kept in mind by all intraocular surgeons as a source of potential difficulties in the perioperative period. Additionally, in light of these changes, patients need to be given realistic expectations regarding the increased risk of complications and more prolonged expected recovery time. In this short review, current reports relating to PEX pathological changes of practical interest to the intraocular surgeon are summarized.

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.

Plasma homocysteine is elevated in patients with exfoliation syndrome

PURPOSE

To compare plasma homocysteine concentrations among patients with exfoliation syndrome, exfoliative glaucoma, normal-tension glaucoma, and normal control subjects without vascular or inflammatory ocular disease or glaucoma.

DESIGN

Cross-sectional study.

METHODS

We tested 25 patients with exfoliation syndrome, 50 with exfoliative glaucoma, 25 with normal-tension glaucoma, and 24 control subjects. Fasting plasma homocysteine concentrations were measured by fluorescence polarization immunoassay. Patients using vitamin supplements or medications known to alter serum homocysteine were excluded.

RESULTS

Homocysteine levels were higher in both exfoliatin groups compared with controls (exfoliation syndrome: P =.003; exfoliative glaucoma: P =.009); levels in normal-tension glaucoma were higher than but not significantly different from those in controls (P =.2). Hyperhomocysteinemia was present in 16 of 25 (64%) exfoliation syndrome patients, 28 of 50 (56%) exfoliative glaucoma patients, 13 of 25 (52%) normal-tension glaucoma patients, and 7 of 24 (29.2%) controls (P =.005). Multiple logistic regression analyses comparing exfoliation syndrome and exfoliative glaucoma patients with controls indicated that elevated plasma homocysteine concentration was a significant risk factor for exfoliation syndrome, in both those patients (odds ratios per 1.0 micromol/l increase in plasma homocysteine concentrations = 1.47; 95% confidence interval [CI] = 1.08-2.0) and in exfoliative glaucoma patients (odds ratio = 1.3; 95% CI = 1.07-1.6). Although exfoliative glaucoma and normal-tension glaucoma patients were not significantly different with respect to hyperhomocysteinemia, logistic regression modeling of exfoliative glaucoma vs normal-tension glaucoma patients showed that an increased homocysteine concentration was a significant risk factor for exfoliation syndrome in the presence of glaucoma (odds ratio per 1.0 micromol/l increase in homocysteine = 1.2, 95% CI = 1.0-1.4). These relationships were not affected by adjustment for potential confounding due to sex, history of hypertension, or other factors.

RESULTS

Elevated plasma homocysteine, a risk factor for cardiovascular disease, is more common in exfoliation syndrome and exfoliative glaucoma patients than healthy controls. Patients with exfoliation syndrome may benefit from measurement of homocysteine levels.

Hyperhomocystinemia in pseudoexfoliation glaucoma

PURPOSE

To determine the prevalence of hyperhomocystinemia in patients with pseudoexfoliation glaucoma.

PATIENTS AND METHODS

This prospective study included 30 patients with glaucoma and 30 age-matched controls with no history of ocular disease who were undergoing routine physical checkups. Plasma homocysteine levels of all the study participants were determined using high-performance liquid chromatography, and values exceeding 15 micromol/L were considered elevated.

RESULTS

The mean plasma homocysteine level was 16.80 +/- 3.20 and 12.39 +/- 1.97 micromol/L in glaucoma patients and controls, respectively (P<0.0001). Fifteen glaucoma patients (50%) had hyperhomocystinemia compared with 3 controls (10%) (P=0.0015).

CONCLUSION

Hyperhomocystinemia may be associated with pseudoexfoliation glaucoma, which may partially explain the increased risk of vascular diseases among patients with pseudoexfoliation syndrome.

Vascular endothelial growth factor is increased in aqueous humor of glaucomatous eyes

PURPOSE

To assess the concentrations of vascular endothelial growth factor (VEGF) in aqueous humor in eyes with and without glaucoma.

METHODS

Concentrations of VEGF were measured using a sandwich ELISA kit in aqueous humor aspirates taken during anterior segment surgery from 87 patients, of whom 54 had glaucoma (27 primary open-angle glaucoma, 8 angle-closure glaucoma, 16 exfoliative glaucoma) and 33 had cataract only.

RESULTS

Vascular endothelial growth factor was detected in all samples. The concentration in eyes with cataract only without glaucoma was 102.4 +/- 29.7 pg/mL (mean +/- SD), which was significantly lower than that from eyes with glaucoma (146.7 +/- 51.8 pg/mL). There were no significant differences between primary open-angle glaucoma (140.4 +/- 51.0 pg/mL), angle-closure glaucoma (142.8 +/- 40.2 pg/mL), and exfoliative glaucoma (158.6 +/- 58.9 pg/mL). An unusually high VEGF concentration was detected in one eye with neovascular glaucoma (759 pg/mL) and two eyes with uveitic glaucoma (322 pg/mL). No effect of age, gender, or previous history of medical, laser, or surgical treatment of the aqueous humor VEGF concentration could be detected ( > 0.05). Aqueous humor and plasma VEGF concentrations were measured and compared in 46 patients. The aqueous humor VEGF concentration (144.2 +/- 107.9 pg/mL) was significantly higher ( < 0.01) than the plasma concentration (79.2 +/- 46.1 pg/mL). No significant correlation was found between aqueous humor and plasma VEGF concentrations.

CONCLUSION

Aqueous VEGF concentration is increased in eyes with glaucoma.