Exfoliation syndrome and exfoliation glaucoma

Exfoliation syndrome and exfoliation glaucoma: Current perspectives and clinical paradigms

Exfoliation syndrome and exfoliation glaucoma comprise a unique age-related ocular aggregopathy characterized by the accumulation of protein complex aggregates in different ocular structures. Recent literature and studies have expanded our knowledge of the clinical characteristic features, phenotypical variations, and molecular pathophysiology associated with disease onset or development of glaucoma. Despite years of studies on the various epidemiological, clinical, and molecular facets of the disease, the exact mechanism of disease onset, formation of aggregates, and the events that trigger the development of glaucoma marking irreversibility in the disease remains elusive. This review elaborates on the existing and new insights that we have gained over the years and highlights gaps in the knowledge about the disease that need future exploration.

Risk factors for exfoliation glaucoma - Current evidence and perspectives

Exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) represent a complex matrix of ocular age-related neurodegenerative changes. Numerous decades of research on this disease entity have highlighted the unique clinical features of ocular protein-complex aggregates, which lead to tissue dysfunction of the ocular outflow channels, leading to irreversible optic nerve damage and glaucoma. While genetic studies have reported several genes associated with XFS and XFG, numerous studies have shown their association with common systemic diseases such as ischemic heart disease, cerebrovascular accidents, and hypertension. Environmental factors are also reported to play a role in the disease pathogenesis by epigenetic control of gene expression and partly explain the difference in the prevalence rates of the disease process. Despite the identification of possible triggers for the disease onset or for the development of glaucoma, the exact mechanisms or the role of several reported risk factors in disease pathogenesis remain a mystery. This review comprehensively evaluated the several risk factors in XFS and XFG while discussing the interactive interplay between the risk factors that determine the disease onset or phenotype in XFS and XFG.

Proteomic characteristics of the aqueous humor in Uyghur patients with pseudoexfoliation syndrome and pseudoexfoliative glaucoma

Pseudoexfoliation syndrome (PEX) is characterized by the deposition of fibrous pseudoexfoliation material (PEXM) in the eye, and secondary glaucoma associated with this syndrome has a faster and more severe clinical course. The incidence of PEX and pseudoexfoliative glaucoma (PEXG) exhibits ethnic clustering; however, few proteomic studies related to PEX and PEXG have been conducted in Asian populations. Therefore, we aimed to conduct proteomic analysis on the aqueous humor (AH) obtained from Uyghur patients with cataracts, those with PEX and cataracts, and those with PEXG and cataracts to better understand the molecular mechanisms of the disease and identify its potential biomarkers. To this end, AH was collected from patients with cataracts (n = 10, control group), PEX with cataracts (n = 10, PEX group), and PEXG with cataracts (n = 10, PEXG group) during phacoemulsification. Label-free quantitative proteomic techniques combined with bioinformatics were used to identify and analyze differentially expressed proteins (DEPs) in the AH of PEX and PEXG groups. Then, independent AH samples (n = 12, each group) were collected to validate DEPs by enzyme-linked immunosorbent assay (ELISA). The PEX group exhibited 25 DEPs, while the PEXG group showed 44 DEPs, both compared to the control group. Subsequently, we found three newly identified proteins in both PEX and PEXG groups, wherein FRAS1-related extracellular matrix protein 2 (FREM2) and osteoclast-associated receptor (OSCAR) exhibited downregulation, whereas coagulation Factor IX (F9) displayed upregulation. Bioinformatics analysis suggested that extracellular matrix interactions, abnormal blood-derived proteins, and lysosomes were mainly involved in the process of PEX and PEXG, and the PPI network further revealed F9 may serve as a potential biomarker for both PEX and PEXG. In conclusion, this study provides new information for understanding the proteomics of AH in PEX and PEXG.

Association between Diabetes and Exfoliation Syndrome

Topic

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

Clinical Relevance

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

Methods

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

Results

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

Conclusion

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

Financial Disclosure(s)

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

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

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

Glaucoma, Pseudoexfoliation and Hearing Loss: A Systematic Literature Review

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

Clinical outcomes of Ahmed glaucoma valve implantation in primary open-angle glaucoma and pseudoexfoliative glaucoma

PURPOSE

To investigate the clinical outcomes of Ahmed glaucoma valve (AGV) implantation in primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG).

METHODS

The patients who underwent AGV implantation for POAG and PEXG between January 2015 and December 2021 in a single tertiary center eye clinic were reviewed retrospectively. Thirty-one eyes with the diagnosis of POAG constituted Group 1 and 40 eyes with the diagnosis of PEXG constituted Group 2. The primary outcome measures were intraocular pressure (IOP) changes after AGV implantation and surgical success at the last visit. We evaluated complete and qualified surgical success using the following three criteria: (1) IOP ≤ 21mmH g, (2) IOP ≤ 18 mmHg, and (3) IOP ≤ 15 mmHg, as well as the absence of any serious complications, such as light perception loss and phthisis bulbi, and additional de novo glaucoma surgery.

RESULTS

The mean follow-up times were 25.2 (± 21.4) months and 27.6 (± 19.8) months for Groups 1 and 2, respectively (p > 0.05). In Groups 1 and 2, the mean preoperative IOPs were 31.9 ± 9.4 mmHg and 32.3 ± 8.4 mmHg, respectively, which significantly reduced to 14.5 ± 0.7 mmHg and 11.6 ± 0.6 mmHg, respectively at the last postoperative visit (p < 0.001 for both). The mean IOP value at the last visit was statistically significantly lower in Group 2 (p = 0.006). At the last visit, the number of eyes with qualified success according to criteria 1, 2, and 3 was 26 (83.9%), 25 (80.6%), and 18 (58.1%), respectively, in Group 1 and 39 (97.5%), 39 (97.5%), and 32 (80%), respectively, in Group 2. The comparison of the qualified success rates showed statistically significantly higher rates in Group 2 for criterion 2 (p = 0.038).

CONCLUSION

AGV implantation had high success rates in both POAG and PEXG, but at the final visit, lower IOP levels were reached in the latter.

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.

Homocysteine and Glaucoma

Elevated levels of homocysteine (Hcy), a non-proteinogenic amino acid, may lead to a host of manifestations across the biological systems, particularly the nervous system. Defects in Hcy metabolism have been associated with many neurodegenerative diseases including glaucoma, i.e., the leading cause of blindness. However, the pathophysiology of elevated Hcy and its eligibility as a risk factor for glaucoma remain unclear. We aimed to provide a comprehensive review of the relationship between elevated Hcy levels and glaucoma. Through a systemic search of the PubMed and Google Scholar databases, we found that elevated Hcy might play an important role in the pathogenesis of glaucoma. Further research will be necessary to help clarify the specific contribution of elevated Hcy in the pathogenesis of glaucoma. A discovery and conceptual understanding of Hcy-associated glaucoma could be the keys to providing better therapeutic treatment, if not prophylactic treatment, for this disease.

Coexistence of MRCS syndrome, extremely long axis and exfoliation syndrome: a case report and literature review

BACKGROUND

The coexistence of MRCS (microcornea, retinal dystrophy, cataract, and posterior staphyloma) syndrome and extremely long axis is rare since microcornea frequently accompanies with diminution of entire anterior segment and occasionally the whole globe. In the case presented here, combination of these two elements were identified, together with XFS (exfoliation syndrome).

CASE PRESENTATION

A 66-year-old Han Chinese woman presented for consultation due to impaired vision which accompanied throughout her entire life span and worsened during the last 2 years. Combination of MRCS syndrome and extremely long axial length was evidently diagnosed in both eyes, with XFS confirmed in her right eye, but mutation screening failed to identify disease-causing sequence variants in some specific genes reported previously, including BEST1 and ARL2. However, likely pathogenic mutations in FBN2 gene were identified. Bilateral cataract phacoemulsification without intraocular lens implantation was performed using scleral tunnel incision and under general anesthesia. At 3-month follow-up, ocular recovery of the patient was satisfactory.

CONCLUSIONS

The case presented here exhibited rare coexistence of MRCS syndrome, extremely long axis and XFS. The complexity of her ocular abnormalities brought challenges to surgical management, in which multidisciplinary collaboration is often required. Furthermore, the genetic analysis in this case yielded a possible novel candidate gene for MRCS syndrome and provided evidence in support of genetic heterogeneity in this phenotype.

Normotensive Glaucoma in the Fellow Eye of Patient with Unilateral Pseudoexfoliation

PURPOSE

To investigate the characteristics of normotensive glaucoma (NTG) in the fellow eye of patients with unilateral pseudoexfoliation syndrome (PXS).

METHODS

This study is a retrospective chart review. We included 313 patients with NTG. Using the 1:1 matched propensity score, only 94 well-matched patients were selected. A total of 47 NTG patients who had PXS in their contralateral eye (PXS group) and 47 NTG patients who did not (control group) were compared. The propensity score was matched based on age, mean intraocular pressure (IOP), baseline retinal nerve fiber layer (RNFL) thickness and baseline mean deviation (MD) of visual field (VF) score. The diagnosis of NTG was based on the presence of glaucomatous optic nerve head injury with VF defect, intraocular pressure less than 22 mmHg, open angles and no pseudoexfoliation material.

RESULTS

The PXS group had a higher ratio of males (34.0%) than the control group (17.0%). No significant differences were observed between the two groups in terms of CCT, axial length, untreated baseline IOP, baseline PSD of VF, systemic blood pressure and follow-up duration. The rate of RNFL thinning was significantly faster in the PXS group (-1.88 ± 2.83 μm/year) compared with the control group (-0.27 ± 5.29 μm/year) (p = 0.02). The progression rate of VF MD was slightly faster in PXS than in the control group, but there was no statistically significant difference (PXS group, -0.33 ± 0.90 dB/year; control group, -0.11 ± 0.84 dB/year; p = 0.236).

CONCLUSIONS

NTG eyes with PXS showed faster RNFL thinning than did control NTG eyes.

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

BACKGROUND

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

RESULTS

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

CONCLUSION

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

Feasibility, efficacy and safety of early lens extraction in patients with pseudoexfoliation glaucoma: a feasibility and pilot study

Purpose

To evaluate the feasibility of a trial to compare the efficacy and safety of initial lens extraction surgery versus medical treatment for people with pseudoexfoliation glaucoma (PXFG) or ocular hypertension (OHT) and pseudoexfoliation syndrome.

Methods

This is a feasibility and pilot randomized controlled trial (RCT) in patients with newly diagnosed PXFG and mild cataract. The study was prospectively registered at ClinicalTrials.gov. An online survey was conducted among members of UK and Eire Glaucoma Society (UKEGS) and Spanish Glaucoma Society (SEG) with the aim of understanding current practices related to interventions for PXFG, the role of phacoemulsification and the willingness to participate in a definite trial. Participants were randomized into either early lens extraction surgery or medical treatment and deferred surgery Primary clinical outcome was intraocular pressure (IOP) at 12 months.

Results

The study was conducted between May 2019 and February 2021. Twelve patients were randomized, six in each group. Median IOP decreased significantly in both arms. Among the secondary outcomes of BVCA, reduction in the number of treatments and quality of life, statistically significant differences were found in favor of lens extraction. There were no differences in other secondary outcomes. No adverse effects occurred. Glaucoma experts would be willing to participate in a RCT.

Conclusions

A trial on early lens extraction surgery compared with medication in PXFG is feasible. Early lens extraction appears to be an effective treatment for PXFG, reducing the number of hypotensive drugs after surgery as well as improving patients’ quality of life.

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

OBJECTIVE

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

DATA SOURCES

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

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

Short-term surgical outcomes of twin-site combined phaco-emulsification and mitomycin-C augmented trabeculectomy in pseudo-exfoliation glaucoma versus primary open-angle glaucoma

Purpose

To compare the short-term outcomes of combined phaco-emulsification with posterior chamber intra-ocular lens and mitomycin augmented trabeculectomy in patients with pseudo-exfoliation glaucoma (PXFG) versus primary open-angle glaucoma (POAG).

Methods

A total of 144 eyes of 144 patients were enrolled in this prospective interventional comparative study, 72 each of which had PXFG and POAG, respectively. All patients underwent twin-site combined phaco-trabeculectomy at a tertiary eye center in India between December 2017 and December 2018 and were followed up for a period of 12 months. The main outcome measures were intra-ocular pressure (IOP), best corrected visual acuity (BCVA), total surgical time, rate of intra-operative and post-operative complications, and the number of ocular hypotensive medications needed. Success rates were determined via Kaplan-Meier survival analysis.

Results

The mean age was 63.9 ± 7.9 years in the POAG group and 66.4 ± 6.8 years in the PXFG group (P - 0.04). The baseline BCVA, IOP, and cup-disc ratio were comparable between two groups. Intra-operative complications and post-operative outcomes were comparable between the two groups. There was a significant drop in anti-glaucoma medications in both groups. Six patients, three (4.2%) in each group, were lost to follow-up after 6 months. Three patients (4.2%) in PXFG needed additional glaucoma intervention for controlling IOP, one patient needed a non-valved glaucoma drainage device, and two patients required diode cyclo-photocoagulation within the follow-up period.

Conclusion

Patients with PXFG had a longer surgical time than POAG. Similar success and complication rates were observed following combined twin-site phaco-trabeculectomy in both POAG and PXFG at 1 year. Combined glaucoma surgery resulted in good IOP control, improvement in BCVA, and lower requirement of ocular hypotensives in both the groups.

Long-Term Outcomes of a Kahook Dual Blade Procedure Combined with Phacoemulsification in Japanese Patients with Open-Angle Glaucoma

We retrospectively evaluated the long-term surgical outcomes of phacoemulsification combined with a Kahook dual blade (KDB) procedure in Japanese patients with open-angle glaucoma. The primary outcome was surgical success or failure. Surgical failure was indicated by a <20% reduction in preoperative intraocular pressure (IOP) or IOP > 18 mmHg (criterion A), IOP > 14 mmHg (criterion B), or requirement for reoperation. Glaucoma medications after surgery and postoperative complications were recorded. Surgical outcomes were compared between primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) groups. The probability of success at 36 months postoperation was 52.5% using criterion A and 36.9% using criterion B. Mean IOP decreased significantly from 19.5 ± 6.9 mmHg preoperatively to 11.9 ± 2.7 mmHg at 36 months, and the mean number of glaucoma medications from 2.4 ± 1.4 to 1.6 ± 1.4 (both p < 0.01). IOP spikes were significantly more common in the ExG group (23.7% vs. 9.1%; p = 0.045), as was the need for additional glaucoma surgery (10.5% vs. 1.8%; p = 0.038). A KDB procedure combined with cataract surgery resulted in significant long-term decreases in IOP and the number of glaucoma medications. The complication rate was higher in eyes with ExG. Therefore, these eyes require more careful management after a KDB procedure.

A global genetic epidemiological review of pseudoexfoliation syndrome

Pseudoexfoliation (PXF) syndrome is an important public health concern requiring individual population level analysis. Disease prevalence differs by geographic location and ethnicity, and has environmental, demographic, genetic, and molecular risk factors have been demonstrated. Epidemiological factors that have been associated with PXF include age, sex, environmental factors, and diet. Genetic and molecular components have also been identified that are associated with PXF. Underserved populations are often understudied within scientific research, including research about eye disease such as PXF, contributing to the persistence of health disparities within these populations. In each population, PXF needs may be different, and by having research that identifies individual population needs about PXF, the resources in that population can be more efficiently utilized. Otherwise, PXF intervention and care management based only on the broadest level of understanding may continue to exacerbate health disparities in populations disproportionally burdened by PXF.

Clinical Analysis of Macular Choroidal Thickness in Pseudoexfoliative Glaucoma and Primary Open-Angle Glaucoma

Purpose

To evaluate the differences in macular choroidal thickness and volume among patients with pseudoexfoliative glaucoma (PXG), patients with primary open-angle glaucoma (POAG), and controls.

Methods

A total of 50 PXG patients (50 eyes) and 56 POAG patients (56 eyes) were selected as the PXG group and the POAG group, respectively, in this case-control study. A total of 54 age-, gender-, IOP-, and axial length-matched healthy individuals (54 eyes) were selected as the control group. Enhanced-depth imaging-optical coherence tomography (EDI-OCT) was used to measure and analyze the choroidal thicknesses and volumes in 9 macular regions of all subjects.

Results

The choroidal thicknesses in the central subfield (CSM), temporal inner macula (TIM), inferior inner macula (IIM), and temporal outer macula (TOM) and the mean macular choroidal thickness were significantly thinner in the PXG group than in the control group (all P < 0.05). The choroidal volumes in the TIM, IIM, and TOM and the mean macular choroidal volume were significantly smaller in the PXG group than in the control group (all P < 0.05). The choroidal thicknesses in the CSM and IIM and the mean macular choroidal thickness were significantly thinner in the PXG group than in the POAG group (all P < 0.05). The choroidal volumes in the IIM and TOM and the mean macular choroidal volume were significantly smaller in the PXG group than in the POAG group (all P < 0.05). Multivariable linear regression analysis showed that the mean macular choroidal thickness was significantly thinner in association with older subjects and longer axial length eyes. There was no association between the macular choroidal thickness of various macular regions and visual field mean defect (MD) in groups PXG and POAG (all P > 0.05).

Conclusions

The macular choroidal thicknesses and volumes (inferior and temporal) in PXG patients were thinner and smaller than those in POAG patients and healthy individuals. The role of choroidal thickness changes in the course of PXG remains unclear. A future prospective study is needed to better define these changes in PXG patients.

Selective Laser Trabeculoplasty for Medically Uncontrolled Pseudoexfoliation Glaucoma in Korean Eyes

Purpose

This study investigated the efficacy and safety of selective laser trabeculoplasty (SLT) in Korean eyes with medically uncontrolled pseudoexfoliation glaucoma (PEXG).

Methods

This retrospective observational study enrolled 43 medically uncontrolled PEXG patients who underwent a 360-degree SLT and were followed up for at least one year after SLT. The intraocular pressure (IOP) before and after SLT at 1 week, 1, 3, 6, and 12 months was evaluated. Treatment success was defined as an IOP reduction of ˃ 20% from the baseline and an IOP lower than 22 mmHg without additional anti-glaucomatous intervention. Additionally, every follow-up medical record was reviewed to assess any possible side effects of SLT.

Results

Based on the Kaplan-Meier survival analysis, the treatment success rate at one year after SLT was 41.9% (18 eyes). For the success group at the one year follow-up, SLT showed a mean IOP reduction of 10.3 ± 5.0 mmHg (from 25.6 ± 4.4 mmHg to 15.2 ± 2.9 mmHg; 39.3%, p < 0.05). Among the 25 eyes that were considered as the treatment failure group, 14 eyes underwent glaucoma filtering surgeries, 4 eyes received additional SLT, and further intervention and follow-up was refused for 7 eyes. During the overall follow-up period, there were no significant adverse events.

Conclusion

SLT is a partially effective and safe procedure for lowering IOP in Korean patients with medically refractory PEXG. Therefore, it can be considered as one of the alternative treatment modalities in patients who are at high risk for conventional filtering surgery.

Correlation of optical coherence tomography and Doppler ultrasonography findings in pseudoexfoliation syndrome

PURPOSE

We aimed to investigate the correlation between the color Doppler imaging (CDI) results and parameters determined by spectral domain optical coherence tomography (SD-OCT) in cases with pseudoexfoliation syndrome (XFS).

METHODS

99 participants were included in this prospective study. Retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), optic nerve head (ONH) measurements were recorded. Perfusions of the ophthalmic artery (OA) and central retinal artery (CRA) were determined and resistivity indices (RI) were calculated.

RESULTS

No statistically significant differences were determined between the groups regarding the RNFL and ONH parameters. Only the minimum GCC thickness value was determined to be reduced in XFS group (n = 49) when compared to the controls (n = 50) (p = 0.018). The OA-RI and CRA-RI values of XFS group were significantly higher than the control group (p < 0.001 and p = 0.001). In XFSs, negative correlations were present between OA-RI and the minimum, average, inferior and inferotemporal regions of GCC thickness (r = - 0.448 p = 0.001, r = - 0.275 p = 0.040, r = - 0.295 p = 0.027, r = - 0.304 p = 0.024, respectively), and also between CRA-RI and minimum GCC values (r = - 0.317, p = 0.017). While a significant relationship was present between age and OA-RI and CRA-RI values in controls, no such correlation was present in XFSs.

CONCLUSIONS

The vascular resistance increased with age in controls, whereas it was independent of age in XFS group. In XFSs, RIs correlated significantly with certain GCC values, but not with RNFL and ONH parameters. It would be beneficial to follow the XFS with CDI as it provides supportive parameters to GCC in order to recognize early changes in XFS.

The depigmentation degree of iris pigment epithelium in pseudoexfoliation syndrome

BACKGROUND

To compare the optical density of iris pigment epithelium (OD_IPE) and iris stromal thickness (IST) measurements in patients having pseudoexfoliation syndrome (PXS) and age-gender matched participants.

METHODS

This is a cross-sectional study. Patients with PXS were enrolled in the study group. Age and gender-matched healthy subjects with no evidence of PXS were recruited as controls. After a comprehensive ophthalmological evaluation, the anterior segment images were acquired using anterior segment spectral-domain optical coherence tomography (AS SD-OCT). The acquired pictures were further analyzed using the ImageJ program. Two investigators measured the OD_IPE and the IST of the subjects, and the repeatability and reproducibility were checked. SPSS program was used for statistical analysis.

RESULTS

The PXS group was comprised of twenty-two eyes (n = 22 patients), and the control group contained twenty-six eyes of 26 age and gender-matched healthy subjects. The mean temporal OD_IPE of the study group was found to be decreased significantly in comparison to the mean temporal OD_IPE of the control eye (p = 0.018). Both the mean nasal (N) and temporal (T) ISTs of the PEX eyes were thinner than the control eyes (p = 0.006 and p = 0.002, respectively). The mean baseline IOP was found to significantly negatively correlate with the OD_IPE in the PEX group at both N and T sides (r = -0.531, p = 0.011 and r = -0.685, p < 0.001, respectively).

CONCLUSION

The pupillary margin IPE was found more depigmented, and the mean N and T IST were significantly thinner in the PEX group by comparison with the age-gender matched healthy controls. The mean baseline IOP was negatively correlated with the pupillary margin's IPE pigmentation degree in patients with PXS.

Candidate Glaucoma Biomarkers: From Proteins to Metabolites, and the Pitfalls to Clinical Applications

Glaucoma is an insidious group of eye diseases causing degeneration of the optic nerve, progressive loss of vision, and irreversible blindness. The number of people affected by glaucoma is estimated at 80 million in 2021, with 3.5% prevalence in people aged 40-80. The main biomarker and risk factor for the onset and progression of glaucoma is the elevation of intraocular pressure. However, when glaucoma is diagnosed, the level of retinal ganglion cell death usually amounts to 30-40%; hence, the urgent need for its early diagnosis. Molecular biomarkers of glaucoma, from proteins to metabolites, may be helpful as indicators of pathogenic processes observed during the disease's onset. The discovery of human glaucoma biomarkers is hampered by major limitations, including whether medications are influencing the expression of molecules in bodily fluids, or whether tests to validate glaucoma biomarker candidates should include human subjects with different types and stages of the disease, as well as patients with other ocular and neurodegenerative diseases. Moreover, the proper selection of the biofluid or tissue, as well as the analytical platform, should be mandatory. In this review, we have summarized current knowledge concerning proteomics- and metabolomics-based glaucoma biomarkers, with specificity to human eye tissue and fluid, as well the analytical approach and the main results obtained. The complex data published to date, which include at least 458 different molecules altered in human glaucoma, merit a new, integrative approach allowing for future diagnostic tests based on the absolute quantification of local and/or systemic biomarkers of glaucoma.

Association of the MYOC p.(Gln368Ter) Variant With Glaucoma in a Finnish Population

Importance

The c.1102C>T, p.(Gln368Ter) variant in the myocilin (MYOC) gene is a known risk allele for glaucoma. It is the most common MYOC risk variant for glaucoma among individuals of European ancestry, and its prevalence is highest in Finland. Furthermore, exfoliation syndrome has high prevalence in Scandinavia, making the Finnish population ideal to study the association of the variant with different types of glaucoma.

Objectives

To examine the association and penetrance of MYOC p.(Gln368Ter) (rs74315329) variant with different types of glaucoma in a Finnish population.

Design, Setting, and Participants

This genetic association study included individuals of Finnish ancestry in the FinnGen project. The participants were collected from Finnish biobanks, and the disease end points were defined using nationwide registries. The MYOC c.1102C>T variant was either directly genotyped or imputed with microarrays. Recruitment of samples to FinnGen was initiated in 2017, and data analysis was performed between December 2019 and May 2020.

Main Outcomes and Measures

The main outcomes were odds ratios (ORs) and penetrance with different types of glaucoma and in different age groups.

Results

A total of 218 792 individuals were included in this study (mean [SD] age 52.4 [17.5] years; 123 579 women [56.5%]), including 8591 (3.9%) with glaucoma, 3412 (1.6%) with primary open-angle glaucoma, 1515 (0.7%) with exfoliation glaucoma, 892 (0.4%) with normal-tension glaucoma, and 4766 (2.2%) with suspected glaucoma. The minor allele frequency of MYOC p.(Gln368Ter) was 0.28%. Individuals with the heterozygous variant had higher odds of primary open-angle glaucoma (OR, 3.36; 95% CI, 2.55-4.37), overall glaucoma (OR, 2.58; 95% CI, 2.12-3.13), suspected glaucoma (OR, 2.53; 95% CI, 1.93-3.26), exfoliation glaucoma (OR, 2.61; 95% CI, 1.60-4.02), and undergoing glaucoma-related operations (OR, 5.45; 95% CI, 2.95-9.28). The penetrance of heterozygous MYOC p.(Gln368Ter) was 5.2% in individuals with primary open-angle glaucoma, 9.6% in individuals with glaucoma, 5.4% in individuals with suspected glaucoma, and 1.9% in individuals with exfoliation glaucoma. There was no significant association with normal-tension glaucoma (OR, 1.69; 95% CI, 0.72-3.35).

Conclusions and Relevance

This genetic association study found that the MYOC p.(Gln368Ter) variant was associated with exfoliation glaucoma. The association with normal-tension glaucoma could not be replicated. These findings suggest that MYOC p.(Gln368Ter) was associated with open-angle glaucoma and exfoliation glaucoma in a Finnish population.

Surgical and laser interventions for pseudoexfoliation glaucoma systematic review of randomized controlled trials

To assess the comparative effectiveness and safety of different surgical and laser techniques in people with pseudoexfoliation glaucoma (PXFG). We conducted a systematic review including randomized controlled trials (RCT) that compared any pair of surgical or laser treatment versus other type of intervention in PXFG. RCT were identified by a highly sensitive search of electronic databases and two individuals independently assessed trial eligibility, abstracted data and assessed risk of bias. We performed Bayesian Meta-Analysis when outcomes were comparable. The search strategy identified 6171 records. Six studies (262 subjects) were included. Two trials analyzed the same pair of surgical interventions comparing phacoemulsification as solo procedure or combined with trabecular aspiration and we performed meta-analysis. Other RCTs compared the following interventions: trabecular aspiration associated with phacoemulsification versus phacotrabeculectomy, non-penetrating deep sclerectomy associated or not with phacoemulsification, selective versus argon laser trabeculoplasty and one-site versus two-site phacotrabeculectomy. For IOP data, none of the trials reported a difference between pairs of surgical techniques, nor changes in visual acuity or number of post-operative medications. The overall risk of bias is moderate to high. There are no apparent differences in efficacy and safety, although with large uncertainty, between surgical or laser techniques for PXFG. Based on the low-quality evidence from the six studies included in this review, it is not possible to justify the preferential use of non-penetrating surgery, MIGS or trabecular aspiration (with or without cataract surgery) in PXFG. Further research is needed to determine the optimal management of this condition.

Correlation between intraocular pressure obtained with water drinking test versus modified diurnal tension curve measurement in pseudoexfoliation glaucoma

PURPOSE

The aim of this paper was to study the correlation and agreement between the intraocular pressure (IOP) peak value and fluctuations detected with the modified diurnal tension curve (mDTC) and the water drinking test (WDT) in pseudoexfoliation glaucoma (XFG) patients.

METHODS

This prospective observational study enrolled 42 eyes of 42 XFG patients. The IOPs were measured at 2-h intervals from 8 am to 4 pm with a Goldmann applanation tonometer by a single observer to establish the mDTC. The WDT was then performed between 4 and 5 pm on the same day and the IOP was measured 4 times at 15-min intervals after water ingestion. The IOP_peak, IOP_mean, IO _min, and IOP_fluctuation were measured with both the mDTC and WDT. The paired sample t test, Spearman's correlation coefficient and Bland-Altman plots were used for statistical analysis.

RESULTS

The mean age of the 42 patients consisting of 24 females and 18 males was 66.9 ± 6.8 years, and the mean central corneal thickness was 517.7 ± 29.1 µm. The mean values with the mDTC and WDT measurements were 15.05 ± 2.75 mmHg and 17.17 ± 3.25 mmHg (p ≤ 0.0001, r = 0.884) for IOP_mean, 16.76 ± 3.45 mmHg and 18.92 ± 3.94 mmHg (p ≤ 0.0001, r=0.787) for IOP_peak, and 13.61 ± 2.56 mmHg and 15.11 ± 2.84 mmHg (p ≤ 0.0001, r=0.824) for IOP_min, respectively, and a positive correlation was present between these values.

CONCLUSION

There was a positive correlation between the peak, minimum, and mean IOP values determined using the mDTC and WDT in treated XFG patients. WDT can be used as an alternative in the assessment of the IOP in these patients as a more practical method.

Twelve-month surgical outcome and prognostic factors of stand-alone ab interno trabeculotomy in Japanese patients with open-angle glaucoma

The purpose of the study was to evaluate the 12-month surgical outcome and prognostic factors of stand-alone ab interno trabeculotomy. The changes in the intraocular pressure (IOP) and medication score and the success rate of the surgery were analyzed. Thirty-four eyes of 29 patients with primary open-angle glaucoma (POAG; n = 16) or pseudoexfoliation glaucoma (PEG; n = 18) with a 12-month follow-up period were included in the study. The decreases in IOP and medication score from the baseline to the all-time-point were statistically significant (P < 0.001). The surgical success rates were 97.1%, 76.5%, and 44.0% at 3 months (90 days), 6 months (180 days), and 12 months (365 days), respectively. A mixed effect Cox model revealed that the type of glaucoma (POAG) was significantly associated with surgical failure (P = 0.044). Furthermore, the surgical success rate was significantly higher in eyes with PEG than it was in those with POAG (P = 0.019). Stand-alone ab interno trabeculotomy significantly lowered both the IOP and the medication score in patients with glaucoma, although almost one quarter of the cases needed additional glaucoma surgeries. The surgical success rate was significantly higher in eyes with PEG than it was in those with POAG.

Prevalence of Pseudoexfoliation Glaucoma Risk-associated Variants Within Lysyl Oxidase-like 1 in an Irish Population

PRECIS

High-risk alleles of risk-associated single-nucleotide polymorphisms (SNPs) within the lysyl oxidase-like 1 (LOXL1) gene are associated with pseudoexfoliation in patients recruited from an Irish population.

PURPOSE

SNPs within the LOXL1 gene have been identified as a major risk factor for pseudoexfoliation syndrome (PXF) and pseudoexfoliation glaucoma (PXFG), specifically SNPs within exon 1 and intron 1 regions of the gene. The common haplotype (G-G) of 2 SNPs within exon 1, rs1048661, and rs3825942, is the strongest associated risk factor for PXF in white populations, but is switched in some populations to act as protective or low risk. Herein, a study was undertaken to genotype an Irish population for PXF/PXFG risk-associated SNPs within LOXL1.

MATERIALS AND METHODS

Patient cohorts of PXFG, PXF, and controls were recruited and genotyped for risk-associated SNPs within exon 1 (rs1048661 and rs3825942), along with 3 SNPs within intron 1 (rs1550437, rs6495085, and rs6495086) of LOXL1.

RESULTS

The risk G alleles of rs1048661 and rs3825942 were most prevalent in PXFG patients, and a significant association was found between rs3825942 and pseudoexfoliation (P=0.04). Genotypes of several intron 1 SNPs were found to be present at higher frequencies within the pseudoexfoliation patient cohort (PXF/PXFG) compared with control patients, wherein rs6495085 showed statistical association (P=0.04). The G-G-G haplotype of rs1048661, rs3825942, and rs6495085 was the most prevalent in PXFG patients compared with control patients or patients with PXF alone. Patients with the G-G-G haplotype were more likely to need surgery, suggestive of a more severe form of disease.

CONCLUSION

Collectively, these results represent the first study to assess the association of LOXL1 SNPs with PXFG in an Irish population.

A comparison of the corneal biomechanics in pseudoexfoliation glaucoma, primary open-angle glaucoma and healthy controls using Corvis ST

Purpose

To compare the corneal biomechanical parameters between pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG) and healthy controls using Corvis ST.

Methods

A prospective, cross-sectional study was conducted which included 132 treatment-naïve eyes which underwent Corvis ST. The study cohort comprised of 44 eyes with PXG, 42 eyes with POAG and 46 healthy controls. Corneal biomechanical parameters, which included corneal velocities, length of corneal applanated surface, deformation amplitude (DA), peak distance and radius of curvature, were compared between the groups using analysis of variance models.

Results

The 3 groups were demographically similar. The mean IOP was 15.7 ±3 mmHg in the control group, 21.3 ±5 mmHg in the POAG group and 25.8 ±7 mmHg in the PXG group (p<0.0001). Corneal pachymetry was similar across the 3 groups. Mean DA was significantly lower (p<0.0001) in the PXG group (0.86 ±0.18 mm) compared to the POAG group (0.97 ±0.14mm) and the control group (1.10 ±0.15mm). Corneal velocities were also found to be statistically significantly different between the groups. However, after adjusting for IOP, there was no difference in any of the biomechanical parameters between the 3 groups.

Conclusion

Corneal biomechanical parameters measured on Corvis ST are not different between eyes with PXG, POAG and healthy controls after adjusting for IOP.

Increased Aqueous Humor GDF15 Is Associated with Worse Visual Field Loss in Pseudoexfoliative Glaucoma Patients

Purpose

To determine whether increased growth differentiation factor 15 (GDF15) in aqueous humor (AH) is associated with worse visual field loss in patients with pseudoexfoliative glaucoma (PXG).

Methods

We recruited 12 patients (6 males, 6 females) with primary open-angle glaucoma (POAG) or PXG who were scheduled to undergo glaucoma surgery. AH was obtained from the initial peripheral paracentesis for the planned glaucoma surgery, and GDF15 levels were quantified with enzyme-linked immunosorbent assay by an investigator masked to clinical information. Humphrey visual field testing was performed as a part of routine care; results were obtained by reviewing the medical record.

Results

AH GDF15 was detectable in patients with POAG and PXG. Increased AH GDF15 was significantly associated with worse mean deviation in patients with POAG (r = -0.94; 95% confidence interval [CI], -0.99 to -0.33; P = 0.02) and PXG (r = -0.92; 95% CI, -0.99 to -0.41; P = 0.01).

Conclusions

AH GDF15 is detectable in patients with PXG and POAG. Elevated AH GDF15 is strongly associated with worse mean deviation in both subgroups. These findings suggest that GDF15 may be a molecular marker of glaucoma severity that is generalizable to multiple types of glaucoma regardless of the underlying etiology.

Translational Relevance

This study provides proof of concept that GDF15, a molecular marker of retinal ganglion stress that was initially identified in rodent models, may have clinical utility as a measure of glaucoma severity not only in POAG but also in PXG.

XEN Gel Stent in Pseudoexfoliative Glaucoma: 2-Year Results of a Prospective Evaluation

PRéCIS:: This study confirms the safety and efficacy of XEN gel stents in the management of pseudoexfoliative glaucoma 2 years after implantation, with success rates similar to primary open-angle glaucoma regardless of the definition of success.

PURPOSE

To compare the long-term safety and efficacy of XEN gel implant surgery (Allergan Inc., Irvine, CA) in patients with pseudoexfoliative glaucoma (PEXG) and primary open-angle glaucoma (POAG).

SETTING

Prospective, interventional study in a tertiary glaucoma center.

METHODS

A total of 110 eyes of 85 patients with POAG (57 eyes) or PEXG (53 eyes) and uncontrolled intraocular pressure (IOP) despite medical treatment underwent combined XEN+cataract surgery or standalone XEN surgery. Mean IOP, mean number of medications, needling rates, and incidence of adverse effects were compared between the 2 groups. Complete surgical success was defined as an unmedicated IOP≤12, 15, 16, or 18 mm Hg at 2 years, both with and without a 20% reduction from baseline.

RESULTS

Combined XEN+cataract surgery was performed in 72% of POAG and 76% of PEXG eyes (P=0.67), the remainder underwent standalone XEN surgery. Patient characteristics were similar between the 2 groups except for older age for the patients with PEXG (78.5±8.5 vs. 71.3±8.7 y; P<0.005). Mean medicated IOP were 19.8±5.8 mm Hg (POAG) versus 19.8±8.2 mm Hg (PEXG) at baseline (P=0.98), and 14.5±3.6 mm Hg (-26.8%) versus 14.2±3.8 mm Hg (-28.3%), respectively, at 2 years (P=0.75). Mean medications concomitantly dropped from 1.9±1.6 (POAG) versus 2.0±1.3 (PEXG) to 0.6±0.9 versus 0.4±0.7, respectively (P=0.29). Using the 16 mm Hg threshold, 51.4% (POAG) versus 57.1% (PEXG) eyes achieved complete success (P=0.70) at 2 years. The difference in success rates between the 2 groups was not statistically significant under any of the definitions of success. By 24 months, needling was performed in 42.8% (POAG) and 43.2% (PEXG) (P=0.64), with an average time to needling of 162.8 and 134.9 days, respectively (P=0.46). The rates of adverse effects were 30.6% (POAG) and 36.4% (PEXG) (P=0.66), and additional glaucoma surgeries were carried out in 14.3% (POAG) versus 15.9% (PEXG) (P=0.89).

CONCLUSIONS

The XEN gel implant as a standalone or combined procedure demonstrated similar efficacy and safety results in PEXG and POAG eyes.

Analysis of Peripapillary and Macular Choroidal Thickness in Eyes with Pseudoexfoliative Glaucoma and Fellow Eyes

Purpose

To compare differences in peripapillary and macular choroidal thickness in pseudoexfoliative glaucoma (PXG) eyes, nonexfoliative fellow eyes, and normal eyes.

Methods

This case-control study included 37 PXG patients (group A: 37 PXG eyes; group B: 37 nonexfoliative fellow eyes) and 37 sex-, age-, and axial length-matched healthy volunteer eyes (group C). Peripapillary and macular choroidal thickness and volume were measured in all subjects via enhanced-depth imaging-optical coherence tomography.

Results

The average peripapillary (AP) choroidal thickness was (130.10 ± 46.14) μm, (131.43 ± 46.00) μm, and (147.89 ± 53.32) μm; average macular (AM) choroidal thickness was (191.72 ± 68.07) μm, (204.62 ± 69.54) μm, and (215.10 ± 45.40) μm; and average volume was (0.59 ± 0.21) μm³, (0.63 ± 0.21) μm³, and (0.65 ± 0.14) μm³ in groups A, B, and C, respectively. NIP choroidal thickness was significantly lower in groups A and B than in group C (P < 0.05). TIM and TOM choroidal thickness and volume were significantly lower in group A than in group C (P < 0.05). NIM, SIM, NOM, IOM, AM choroidal thickness and volume, and CSM choroidal thickness were significantly lower in group A than in group B (P < 0.05). CSM, TIM, and TOM in group A and TIM, TOM choroidal thickness, and volume in group B were significantly lower than in group C (P < 0.05).

Conclusions

NIP choroidal thickness in PXG eyes and nonexfoliative fellow eyes and temporal macular choroidal thickness in PXG eyes were significantly lower than in normal eyes. Macular choroidal thickness (except in temporal regions) was significantly lower in PXG eyes than in nonexfoliative fellow eyes. Changes in peripapillary and macula choroidal thickness further elucidate the choroid's role in PXG development and progression.

[Spatial contrast sensitivity in patients with primary open-angle glaucoma and ocular hypertension]

Up to now, there has not been a comparison of spatial contrast sensitivity (SCS) in patients with primary and pseudoexfoliation open-angle glaucoma (POAG; PEG) and ophthalmic hypertension (OH).

PURPOSE

To study the characteristics of SCS in patients with POAG, PEG (as well as in the paired eye without glaucoma) and OH.

MATERIAL AND METHODS

The work was performed in the period from 2011 to July 2017. Analytical, observational case-control study data was analyzed. The study included 1380 patients under dynamic observation; in accordance with inclusion and non-inclusion criteria, 290 patients (540 eyes) with POAG, PEG, OH, as well as healthy people were included in the study. SCS was measured using 'Zebra v 3.0' software developed by the laboratory of clinical physiology of vision named after S.V. Kravkova in collaboration with 'Astroinform SPE' LLC. Patients were shown vertical achromatic (black and white) and colored (red, green, and blue) gratings of specific spatial frequencies (0.5; 1; 2; 4; 8; 16 cycles/degree). Among the patients of the study, 243 (83%) were female and 47 (17%) were male. The average age of all patients at the time of inclusion in the study was 67.75 (62.8; 74.5); 67.84±8.7 years.

RESULTS

The study revealed an increase of SCS in patients with OH and their tendency for a slight increase in the contralateral eye with unilateral PEG in comparison with measurements taken from patients of POAG and PEG groups.

CONCLUSION

The revealed increase of SCS is likely to be a consequence of increased or preserved hemodynamic characteristics in the vessels of the eye and orbit in patients with hypertension and in the contralateral eye in unilateral glaucoma, as described in our previous publications. At the same time, generalized changes in the vascular wall in patients with 'PEG-' on the paired eye only predetermine a tendency for an increase of SCS indices.

Recent advances in risk factors associated with ocular exfoliation syndrome

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

Selective laser trabeculoplasty in exfoliative glaucoma eyes with prior argon laser trabeculoplasty

PURPOSE

To explore the efficacy of selective laser trabeculoplasty (SLT) within eyes with exfoliative glaucoma and history of prior argon laser trabeculoplasty (ALT).

METHODS

A single-centre trial consisting of 47 patients (47 eyes) with uncontrolled exfoliative glaucoma. The main outcome measure was intraocular pressure (IOP) reduction 3 and 9 months after SLT. Treatment success was defined as reduction from the preoperative IOP by 20% and 2 mmHg (<12 mmHg), 3 mmHg (12-16 mmHg) or 4 mmHg (>16 mmHg) depending on the baseline IOP.

RESULTS

Patient age was 79.3 ± 7.6 years (mean ± SD) and gender distribution 15 males and 32 females. The mean pre-SLT IOP was 15.6 ± 5.1 (range 9-28) mmHg, and mean number of glaucoma drugs 2.0 ± 1.2. The mean interval between prior ALT and SLT was 44.0 ± 36.9 (range 11-137) months. After SLT, the mean IOP change was -2.7 ± 4.2 mmHg (-14.8 ± 23.5%) at 3 months, and -2.8 ± 3.5 mmHg (-16.3 ± 19.4%) at 9 months. Pre-SLT IOP correlated with the IOP reduction at 3 months (r = 0.530, p < 0.001) and at 9 months (r = 0.432, p = 0.007). The overall success rate was 50% at 3 months, and 42% at 9 months. At both 3 and at 9 months, the cut-off level for treatment success was achieved when preoperative IOP was 18 mmHg and above. IOP lowering effect of SLT did not correlate with the number of glaucoma drugs, age, gender or use of prostaglandin inhibitors. Neither postoperative iritis nor other adverse effects were documented during the follow-up.

CONCLUSIONS

Selective laser trabeculoplasty is a safe and noteworthy treatment option to reduce IOP in exfoliative glaucoma eyes, especially with pre-SLT IOP over 18 mmHg.

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.

Epidemiology of Exfoliation Syndrome

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of intraocular lens scleral fixation with the friction knot technique

PURPOSE

To examine the clinical outcomes of intraocular lens (IOL) scleral fixation with the friction knot technique.

METHODS

Retrospective case series of 152 eyes of 152 patients with inadequate capsular bag support operated with the friction knot IOL scleral fixation technique by a single surgeon. The fixated IOLs were one-piece or three-piece models all with open loop haptics. Main outcome measures were change in corrected distance visual acuity (CDVA) and postoperative complications.

RESULTS

The mean follow-up time was 11.7 months (median 4.9, range 0.7-64.8). The mean logarithm of the minimum angle of resolution CDVA improved from preoperative 0.77 ± 0.73 (Snellen 20/118 ± 7.3 lines) to 0.44 ± 0.56 (Snellen 20/55 ± 5.6 lines) at the final visit (p < 0.001). The main postoperative complications were ocular hypertension (30.3%), uveitis-glaucoma-hyphaema syndrome (12.5%; UGHS), vitreous haemorrhage (11.2%) and retinal detachment (8.6%). Two (1.3%) cases of suture breakage were seen. In multivariate Cox regression analysis, age under 60 years [hazard ratio (HR) = 5.41; 95% confidence interval (CI) 1.95-15.01] and scleral fixated one-piece IOL (HR = 4.23; 95% CI 1.44-12.44) were found as significant independent risk factors for developing new UGHS.

CONCLUSION

The friction knot technique provides a firm scleral fixation. Scleral fixation may successfully be utilized in dislocated three-piece IOLs with loop haptics. We recommend avoiding scleral fixation of one-piece IOLs in young patients due to a high risk of UGHS.

A Comparison of Resource Use and Costs of Caring for Patients With Exfoliation Syndrome Glaucoma Versus Primary Open-Angle Glaucoma

PURPOSE

To characterize differences in resource utilization and cost of managing enrollees with exfoliation glaucoma (XFG) compared to primary open-angle glaucoma (POAG).

DESIGN

Retrospective utilization and cost comparison using Medicare claims data.

METHODS

We identified Medicare beneficiaries with XFG or POAG and ≥5 years of continuous enrollment from January 2008 to December 2014. We distinguished newly diagnosed cases from those with preexisting disease. We compared ophthalmic resource utilization and costs over 2 years of follow-up for persons with newly diagnosed and preexisting XFG vs those with POAG. Main outcome measures were number of clinic visits, diagnostic procedures, medication fills, laser and incisional surgery, and mean eye care costs per beneficiary.

RESULTS

Among 192 eligible enrollees (median age 77.6 years) with newly diagnosed XFG and 7339 enrollees (median age 77.3 years) with newly diagnosed POAG, those with XFG had more office visits (mean, 9.1 vs 7.9; P = .001), cataract surgery (34.9% vs 19.0%; P < .0001), and glaucoma surgery (28.7% vs 19.7%, P = .002). They also experienced 27% higher mean total eye care costs ($3260 vs $2562, P = .0001) over 2 years of follow-up. Among 2745 enrollees (median age 80.5 years) with preexisting XFG and 89 036 persons (median age 79.5) with preexisting POAG, persons with XFG had more office visits (mean 9.3 vs 7.3; P < .0001), perimetry (85.3% vs 79.8%; P < .0001), cataract surgery (23.4% vs 12.3%; P < .0001), laser trabeculoplasty (18.6% vs 9.6%; P < .0001), and trabeculectomy (8.1 vs 1.8%; P < .0001) and experienced 37% higher total mean eye care costs ($3764 vs $2739; P < .0001).

CONCLUSIONS

Healthcare resource utilization and costs are substantially higher for managing patients with XFG compared to POAG.

Evaluation of the retinal nerve fiber layer and ganglion cell complex thicknesses in patients with exfoliation syndrome

Background/aim

This study aimed to evaluate retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses using spectral domain optical coherence tomography (SD-OCT) in both unilateral and bilateral exfoliation syndrome (XFS) patients

Materials and methods

Twenty-four patients with unilateral XFS, 20 patients with bilateral XFS, and 23 healthy subjects were enrolled in this study. Eyes with XFS were compared with both fellow eyes and age-matched control subject eyes in terms of mean and segmental RNFL thickness and minimum, mean, and segmental GCC thickness.

Results

In the bilateral XFS group, minimum GCC of the right eye (75.80 ± 11.6 μm) was significantly thinner compared with the right eyes of the control group (81.83 ± 6.6 μm) (P < 0.05). Also, superior RNFL was thinner in the right eye (106.90 ± 16.7 μm) compared with left eye (114.15 ± 18.1 μm) in the bilateral XFS group (P < 0.05). No significant differences in the unilateral XFS group were detected in GCC and RNFL analysis.

Conclusion

Minimum GCC value may be the first parameter affected in the conversion of XFS to exfoliative glaucoma followed by RNFL changes.

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.

One-year follow-up of the XEN® implant with mitomycin-C in pseudoexfoliative glaucoma patients

PURPOSE

To evaluate the intraocular pressure-lowering effect, the safety profile, and the success rate of the XEN45 Gel Stent (Allergan, Dublin, Ireland) in patients with pseudoexfoliative glaucoma.

METHODS

Retrospective study conducted on patients with pseudoexfoliative glaucoma, with or without cataract, who underwent XEN45 implantation surgery with subconjunctival mitomycin-C and had a minimum postoperative follow-up period of 12 months. The primary outcome measure was intraocular pressure reduction at 1 year as compared to baseline. Complete success was defined as a postoperative intraocular pressure reduction of ⩾20% from preoperative baseline at 12 months without any glaucoma medications. Qualified success was defined as a postoperative intraocular pressure reduction of ⩾20% at 12 months with medications.

RESULTS

Of the 24 screened patients, 21 eyes of 20 patients met the inclusion/exclusion criteria and were included in the study. A total of 13 (62%) eyes underwent XEN alone surgery and 8 (38%) eyes had combined XEN + cataract surgery. Mean intraocular pressure was significantly reduced from 21.1 (3.8) mmHg at baseline to 15.2 (3.9) mmHg at 1 year, p < 0.001. Mean antiglaucoma medications dropped from 2.95 (0.97) preoperatively to 1.23 (1.22) at month 12 (p < 0.001). Of the 21 eyes included in the study, 18 (85.7%) were considered as success, 6 (28.6%) as complete success, and 12 (57.1%) as qualified success. Five eyes required needling revision. Complications included uveitis, choroidal detachment, hyphema, and cystoid macular edema in 2, 1, 1, and 1 eye, respectively.

CONCLUSION

XEN45 Gel Stent implant significantly reduced the intraocular pressure and the number of antiglaucoma medications in patients with pseudoexfoliative glaucoma.

Intravenous Hypertonic Saline to Lower Intraocular Pressure in Ocular Hypertension and Primary Open-angle and Exfoliation Glaucoma

PURPOSE

The purpose of this article was to quantitate the effect of intravenous hypertonic saline (IVHTS) on elevated intraocular pressure (IOP) among 3 groups of glaucoma patients or suspects.

MATERIALS AND METHODS

Among the forty-four patients with IOP 24 to 30 mm Hg included in this study, 13 had ocular hypertension (OHT), 14 primary open-angle glaucoma (POAG), and 17 exfoliation glaucoma (ExG). Participants received a bolus of 23.4% IVHTS (1.0 mmol/kg) through an antecubital vein. We measured IOP, heart rate, and blood pressure before the bolus, thereafter every minute for 10 minutes, and less frequently for 2 hours.

RESULTS

The median baseline IOP was 24 mm Hg (range, 24 to 30 mm Hg), 26.5 mm Hg (range, 24 to 30 mm Hg), and 26 mm Hg (range, 24 to 30 mm Hg) in OHT, POAG, and ExG patients, respectively. Sixteen minutes after the bolus, IOP was a median of 9 mm Hg (range, 4 to 12 mm Hg), 10 mm Hg (range, 6 to 12 mm Hg), and 10 mm Hg (range, 4 to 14 mm Hg) lower in OHT, POAG, and ExG groups (P=0.70), respectively. After 1 hour, the median IOP reduction was similar between ExG (9 mm Hg; range, 4 to 14 mm Hg) and POAG patients (9.5 mm Hg; range, 6 to 12 mm Hg) but lower in OHT patients (6 mm Hg; range, 2 to 9 mm Hg; P=0.006). Heart rate decreased by a median of 7 beats/min. Blood pressure increased within 3 minutes (median, mm Hg; 15 systolic; 5 diastolic), but returned to baseline at 10 minutes. Within 1 to 3 minutes of treatment, 36 (82%) patients felt pain in the infusion arm, and 29 (66%) reported a feeling of warmth in their head.

CONCLUSIONS

IVHTS reduced IOP effectively in all groups.

LncRNAs in genetic basis of glaucoma

Glaucoma is an umbrella term used to designate a heterogeneous group of ocular disorders characterised by progressive excavation of the optic disc, optic atrophy and gradual loss of the visual field caused by the slow death of retinal ganglion cells and their axons. Glaucoma can potentially lead to blindness if left untreated. It usually starts from the periphery and progresses gradually toward the centre of the visual field. Vision loss caused by glaucoma is irreversible and causes a heavy burden on affected families and society, therefore the importance of early diagnosis and prevention should be emphasised. Genetic factors appear to play a role in glaucoma pathogenesis; it has been shown that individuals with a positive family history are at a greater risk because they are more likely predisposed be affected. Notable advances have been recorded in the past decade concerning the genetic and environmental factors likely to contribute or cause glaucoma with the discovery of multiple glaucoma-associated genes and genetic loci. Thorough investigations by a handful of studies on the function of long non-coding RNAs discovered that, although lacking protein-coding potential, lncRNAs can still participate in the regulation of gene expression at various levels, thus their possible implication in different disease aetiologies. In this review, we focus on the lncRNAs characteristics and its regulation, and summarise these results from separate, independent, glaucoma-related studies in addition to discussing possible pathways by which lncRNAs might contribute to glaucoma.

What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago?

Exfoliation syndrome (XFS) is a systemic disease with significant ocular manifestations, including glaucoma and cataract. The disease impacts close to 70 million people globally and is now recognised as the most common identifiable cause of open-angle glaucoma. Since the discovery of XFS 100 years ago by Dr John G. Lindberg, there has been considerable advancement in understanding its pathogenesis and resulting clinical implications. The purpose of this paper is to summarise information regarding the epidemiology, pathophysiology, ocular manifestations and systemic associations of XFS with the objective of sharing clinical pearls to assist in early detection and enhanced management of patients.

Comparison of long-term results of trabeculectomy to treat pseudoexfoliative glaucoma and primary open angle glaucoma

AIM

To compare the long term outcome of trabeculectomy in patients with pseudoexfoliative glaucoma (PEG) and primary open angle glaucoma (POAG) in terms of surgical success.

METHODS

The success of the trabeculectomy was evaluated by three criteria. Criterion A: intraocular pressure (IOP) ≤21 mm Hg and decrease in IOP ≥20%; Criterion B: IOP ≤18 mm Hg and decrease in IOP ≥30%; Criterion C: IOP ≤15 mm Hg and decrease in IOP ≥50%. Patients that met these criteria without medical treatment were considered to be completely successful, while those that met these criteria with medical treatment were considered partially successful. Significance levels of differences between the POAG and PEG groups in the Kaplan-Meier survival curves were calculated with the log-rank test.

RESULTS

Sixty-four eyes from 64 patients with PEG and 51 eyes from 51 patients with POAG were evaluated. No significant differences were detected between the PEG and POAG groups according to full or partial success relative to each of the three criteria (A: P=0.73, 0.32; B: P=0.73, 0.31; C:P=0.90, 0.27).

CONCLUSION

There is no difference in the long-term success of trabeculectomy between PEG and POAG patients whose clinical characteristics are otherwise the same.