Glaucoma and intraocular pressure in EPIC-Norfolk Eye Study: cross sectional study

Enhanced in vivo performance of topical ocular acetazolamide nanocrystals: A novel approach for glaucoma treatment

High intraocular pressure (IOP) is the main risk factor for glaucoma progression. Acetazolamide (AZM) presents a potent IOP-lowering effect but is only administered orally due to its low aqueous solubility and ocular permeability. This study aimed to develop AZM nanocrystals (AZM-NC) as an alternative for its topical ocular delivery. AZM-NC were obtained by wet bead milling technique followed by spray-drying, and a mixture design study was conducted to evaluate the optimal drug-to-stabilizer ratio regarding colloidal properties and stability. AZM-NC exhibited an average particle size of 299.7 ± 8.8 nm, a polydispersity index of 0.13 ± 0.01, and a zeta potential of -29.0 ± 0.9 mV, which remained mostly unchanged for at least 60 days when the dried powder was stored at room temperature. Fourier-transformed spectroscopy and powder X-ray diffraction analyses revealed no chemical or crystallinity changes in AZM-NC compared with AZM, respectively. Additionally, AZM-NC demonstrated increased drug saturation concentration, globular shapes, and higher adhesive properties than normal-sized AZM powder. Topical ocular administration of AZM-NC in albino male rabbits showed no clinical signs of ocular damage. Further, in vivo studies revealed a significant IOP reduction of up to 32 % of the basal IOP (-4.8 ± 1.2 mmHg, p < 0.05) in normotensive rabbit eyes (n = 7), after 4 h of AZM-NC suspension topical application, compared to groups treated with AZM suspension, normal saline solution and, AZOPT® (-1.8 ± 1.4 mmHg). Thus, AZM-NC could present a promising approach for developing an eye drop formulation for the localized management of glaucoma.

Application of machine learning techniques in GlaucomAI system for glaucoma diagnosis and collaborative research support

This paper proposes an architecture of the system that provides support for collaborative research focused on analysis of data acquired using Triggerfish contact lens sensor and devices for continuous monitoring of cardiovascular system properties. The system enables application of machine learning (ML) models for glaucoma diagnosis without direct intraocular pressure measurement and independently of complex imaging techniques used in clinical practice. We describe development of ML models based on sensor data and measurements of corneal biomechanical properties. Application scenarios involve collection, sharing and analysis of multi-sensor data. We give a view of issues concerning interpretability and evaluation of ML model predictions. We also refer to the problems related to personalized medicine and transdisciplinary research. The system can be a base for community-wide initiative including ophthalmologists, data scientists and machine learning experts that has the potential to leverage data acquired by the devices to understand glaucoma risk factors and the processes related to progression of the disease.

Optic nerve assessment with stereo photographs and ultra-widefield scanning laser ophthalmoscope images

CLINICAL RELEVANCE

Clinical evaluation of the optic nerve using 3-D stereo disc photographs is considered the gold standard for estimating vertical cup-to-disc ratios. Ultra-widefield retinal imaging has gained increasing popularity to document and screen the health of the retina and optic nerve.

BACKGROUND

Glaucoma is often first identified or suspected based on initial optic nerve assessment. Despite technological advancements in imaging, stereo disc photography remains the gold standard of optic nerve assessment. This study compared vertical cup-to-disc ratio (VCDR) estimations using ultra-widefield scanning laser ophthalmoscopy images with estimations using paired stereo disc images.

METHODS

Thirty-five healthy and 35 glaucomatous eyes were imaged using Zeiss VISUCAM® PRO NM and Optos Monaco® (optomap®) [Registered in U.S. Patent and Trademark Office] devices. Four experienced clinicians assessed each image in a masked fashion and graded the VCDR. Stereo viewers and review software tools were used to determine VCDRs. Bland-Altman plots and regression/correlation analyses were used to check VCDR agreement.

RESULTS

Bland-Altman analyses showed low mean differences between devices with VCDR estimation for each grader (-0.03, +0.01, -0.02, and +0.03). Difference vs. means plots suggest stable differences across the range of measurement.

CONCLUSIONS

VCDR estimations were comparable using optomap® images and VISUCAM® PRO NM stereo optic disc images.

Glaucoma treatment and deprivation: time-series analysis of general practice prescribing in England

BACKGROUND

Despite advances in glaucoma management, topical eyedrop treatment has been paramount, with prostaglandin analogues (PGAs) being first-line agents. While late presentation is linked with deprivation, there is no recent research examining associations between deprivation and prescribing within primary care.

AIM

To explore PGA prescribing in general practice over a 6-year timeline, assessing associations with deprivation.

DESIGN & SETTING

Analysis of NHS Business Services Authority (NHSBSA) data for general practice prescribing in England from April 2016-March 2022.

METHOD

Glaucoma treatments by GP prescribers were extracted, identifying ~9.11-9.58 million prescriptions/annum. Data were linked to Index of Multiple Deprivation (IMD) quintiles of GP practices. Crude rates per 1000 population were calculated using population data from NHS Digital. Time-series analyses facilitated comparison in prescribing nationally and in deprived areas. Autoregressive Integrated Moving Average (ARIMA) modelling facilitated measurement of synchrony between time series using cross correlation.

RESULTS

PGAs and fixed combination eyedrops accounted for approximately two-thirds of glaucoma-related prescribing. Prescriptions per month increased slightly over a 6-year timeline, but rates per 1000 population reduced in 2020-2021 during the COVID-19 pandemic. The number of PGA prescriptions dispensed in deprived areas was lower than all other quintiles. Cross-correlation analysis indicates a lag of ~12 months between average PGA prescribing nationally versus more deprived areas.

CONCLUSION

The rate of PGA prescribing in primary care was substantially lower in deprived versus affluent areas, with delayed uptake of PGAs in more deprived areas of ~12 months. Further research is needed to explore reasons for this discrepancy, permitting strategies to be developed to reduce unwarranted variation.

Glaucoma: what the neurologist needs to know

Glaucoma is a progressive optic neuropathy resulting from pathological changes at the optic disc due to elevated intraocular pressure. Its diagnosis, treatment and follow-up are almost entirely conducted in ophthalmology clinics, with screening conducted by community optometrists. Despite this, neurologists may encounter glaucoma in both its acute presentation (as angle closure, presenting as acute headache) and its chronic forms (often as optic neuropathy of unknown cause). An awareness of the underlying pathological process, and the key distinguishing signs and symptoms, will allow neurologists to identify the glaucomatous process rapidly. Timely referral is essential as glaucoma invariably results in progressive visual loss without treatment. This review therefore condenses the wide field of glaucoma into a practical summary, aimed at practitioners with limited clinical experience of this ophthalmic condition.

Comparative outcomes of selective laser trabeculoplasty delivered by optometrists compared with ophthalmologists: a UK-based multicentre observational study

BACKGROUND

Selective laser trabeculoplasty (SLT), a National Institute for Care and Health Excellence recommended first-line treatment for open-angle glaucoma and ocular hypertension, is increasingly delivered by optometrists. This retrospective multicentre observational study evaluates real-world outcomes of SLT comparing optometrist-treated to ophthalmologist-treated eyes.

METHODS

Adults aged ≥40 years receiving first SLT treatment at three UK hospital eye units (Aintree, Manchester, Macclesfield) between 1 August 2018 and 1 August 2021 were analysed using anonymised local audit data. Outcomes included intraocular pressure (IOP), visual acuity (VA), drop burden, complications including post-SLT IOP spikes, and composite treatment failures including repeat laser or glaucoma surgery, evaluated at 6-monthly intervals up to 24 months. Groups were compared with parametric and non-parametric tests, accounting for intereye correlation, and Kaplan-Meier survival analysis using composite treatment failure endpoints was conducted.

RESULTS

207 eyes (131 patients) were analysed, 84 (56 patients) optometrist-treated eyes compared with 123 ophthalmologist-treated eyes (75 patients). No statistically significant differences (p>0.05) were found in change in VA, IOP or glaucoma drops from pre-SLT baseline between optometrist and ophthalmologist-treated eyes, at all time points. More cataracts were detected in optometrist-treated eyes, however, this did not affect differences in VA or cataract surgery frequency. More optometrist-treated eyes underwent glaucoma surgery, however, ophthalmologist-treated eyes had higher drop burden and chance of composite treatment failure up to month 18.

CONCLUSION

Outcomes of SLT treatment by optometrists and ophthalmologists are comparable up to 24 months post-treatment. Ophthalmologist-treated eyes may have had more aggressive eye-drop treatment, preventing the need for surgery.

Screening Strategies and Methodologies

PRCIS

While glaucoma is a leading cause of irreversible vision loss, it presents technical challenges in the design and implementation of screening. New technologies such as PRS and AI offer potential improvements in our ability to identify people at high risk of sight loss from glaucoma and may improve the viability of screening for this important disease.

PURPOSE

To review the current evidence and concepts around screening for glaucoma.

METHODS/RESULTS

A group of glaucoma-focused clinician scientists drew on knowledge and experience around glaucoma, its etiology, and the options for screening. Glaucoma is a chronic progressive optic neuropathy affecting around 76 million individuals worldwide and is the leading cause of irreversible blindness globally. Early stages of the disease are asymptomatic meaning a substantial proportion of cases remain undiagnosed. Early detection and timely intervention reduce the risk of glaucoma-related visual morbidity. However, imperfect tests and a relatively low prevalence currently limit the viability of population-based screening approaches. The diagnostic yield of opportunistic screening strategies, relying on the identification of disease during unrelated health care encounters, such as cataract clinics and diabetic retinopathy screening programs, focusing on older people and/or those with a family history, are hindered by a large number of false-positive and false-negative results. Polygenic risk scores (PRS) offer personalized risk assessment for adult-onset glaucoma. In addition, artificial intelligence (AI) algorithms have shown impressive performance, comparable to expert humans, in discriminating between potentially glaucomatous and non-glaucomatous eyes. These emerging technologies may offer a meaningful improvement in diagnostic yield in glaucoma screening.

CONCLUSIONS

While glaucoma is a leading cause of irreversible vision loss, it presents technical challenges in the design and implementation of screening. New technologies such as PRS and AI offer potential improvements in our ability to identify people at high risk of sight loss from glaucoma and may improve the viability of screening for this important disease.

Change of Intraocular Pressure Over 5 Years and its Relationship to Cardiovascular Parameters: Results From the Gutenberg Health Study

Purpose

To investigate the longitudinal change in intraocular pressure (IOP) over 5 years and its relationship with cardiovascular parameters in a population-based sample in Germany.

Methods

The Gutenberg Health Study is a prospective, observational, single-center cohort study. The sample was equally stratified for sex, residence, and age decade. IOP was measured with noncontact tonometry at baseline and at 5-year follow-up. Cardiovascular parameters, including body mass index (BMI), systolic blood pressure, and diabetes status, were assessed. Participants without IOP measurement at one time point, who were taking IOP-lowering medications, or who had ophthalmic surgery during the 5-year follow-up interval were excluded, as well as those with glaucoma diagnosis. Univariable and multivariable linear regression analyses were conducted.

Results

This analysis included 9633 participants (48.9% female). The mean IOP increased from 14.04 ± 2.78 mmHg at baseline to 14.77 ± 2.92 mmHg at 5-year follow-up (P < 0.001). In multivariable linear regression analyses, an increase in BMI was associated with an increase in IOP over time (P < 0.001), whereas a higher baseline BMI was associated with a lower IOP change (P < 0.001). Higher age and male sex were associated with higher IOP change (P < 0.001). A change in systolic blood pressure was associated with IOP change, whereas baseline systolic blood pressure and diabetes status were not associated.

Conclusions

This population-based study found a relationship between IOP change over 5 years and BMI and systolic blood pressure change, respectively. These findings suggest the importance of monitoring cardiovascular risk factors in IOP management.

Qualitative Development of the Allergan Satisfaction with Treatment Experience Questionnaire (ASTEQ) Instrument, a Patient-Reported Outcome Measure in Glaucoma and Ocular Hypertension

INTRODUCTION

Sustained-release intraocular implants provide a therapeutic option for open-angle glaucoma (OAG) and ocular hypertension (OHT) patients who are non-compliant with eyedrops. Currently, there are no published patient-reported outcome (PRO) measures that assess treatment satisfaction with intraocular implants. To address this gap, a new PRO instrument, the Allergan Satisfaction with Treatment Experience Questionnaire (ASTEQ), has been developed in accordance with Food and Drug Administration guidance.

METHODS

Qualitative research interviews were conducted among patients with OAG/OHT who had received three intraocular injections of a sustained-release bimatoprost (10 or 15 µg) implant within the clinical trial setting. A preliminary conceptual framework capturing treatment satisfaction concepts in glaucoma, as identified from the literature, was used to develop a semi-structured interview guide. A concept elicitation (CE) interview to identify aspects of the glaucoma treatment experience pertinent to intraocular implants provided content for a draft instrument. A cognitive debriefing (CD) interview to test the instrument's interpretability, relevance, and validity informed its subsequent refinement. Interview analysis followed a grounded theory approach to identify data patterns and relationships.

RESULTS

CE interviews (n = 19) indicated that participants' main considerations in rating satisfaction with implant treatment were physical comfort during preparation for the implant and implant administration, anxiety about the procedure, frequency of implant administration, possible side effects, convenience and accessibility of the implant, relationship with the clinician, and lifestyle fit. Draft ASTEQ revision based on CD interviews (n = 20) and readability tests yielded a nine-item ASTEQ instrument comprising satisfaction with overall implant experience and frequency of administration, occurrence/bother of immediate and long-term side effects, worry about implant administration and possible risks/side effects, and physical discomfort during preparation for the implant and implant administration.

CONCLUSION

The ASTEQ instrument has demonstrated content validity in patients with OAG/OHT treated with a sustained-release bimatoprost implant. Further research is necessary to evaluate its psychometric properties.

Influence of sex on chronic steroid-induced glaucoma: 24-Weeks follow-up study in rats

The objective was to evaluate ocular changes based on sex in steroid-induced glaucoma models in rats comparing healthy controls, over 24 weeks follow-up. Eighty-nine Long-Evans rats (38 males and 51 females) with steroid-induced glaucoma were analysed. Two steroid-induced glaucoma models were generated by injecting poly-co-lactic-glycolic acid microspheres loaded with dexamethasone (MMDEX model) and dexamethasone-fibronectin (MMDEXAFIBRO model) into the ocular anterior chamber. Intraocular pressure was measured by rebound tonometer Tonolab®. Neuroretinal function was analysed using dark- and light-adapted electroretinography (Roland consult® RETIanimal ERG), and structure was analysed using optical coherence tomography (OCT Spectralis, Heidelberg® Engineering) using Retina Posterior Pole, Retinal Nerve Fibre Layer and Ganglion Cell Layer protocols over 24 weeks. Males showed statistically (p < 0.05) higher intraocular pressure measurements. In both sexes and models neuroretinal thickness tended to decrease over time. In the MMDEX model, males showed higher IOP values and greatest percentage thickness loss in the Ganglion Cell Layer (p = 0.015). Females receiving MMDEXAFIBRO experienced large fluctuations in thickness, a higher percentage loss (on average) in Retina Posterior Pole (p = 0.035), Retinal Nerve Fibre Layer and Ganglion Cell Layer than aged-matched males, and the highest thickness loss rate by mmHg. Although no difference was found by sex in dark- and light-adapted electroretinography, increased amplitude in photopic negative response was found in MMDEX males and MMDEXAFIBRO females at 12 weeks. Although both glaucoma models used dexamethasone, different intraocular pressure and neuroretinal changes were observed depending on sex and other influential cofactors (fibronectin). Both sex and the induced glaucoma model influenced neuroretinal degeneration.

Genomics enabling personalised glaucoma care

Glaucoma is a leading cause of visual impairment and a significant public health concern, but despite ongoing advances in our understanding of the disease, several important clinical challenges remain. With the number of affected people projected to increase substantially over coming decades, novel approaches to screening, risk stratification, therapy and glaucoma research are essential to deal with this expanding burden in an efficient and cost-effective manner. Genomics may hold the key to unlocking further biological insights and enabling precision medicine, in which glaucoma care is tailored to the individual patient, based on their unique profile for disease. Here, we provide an overview of how genomics may enable cost-effective targeted population screening and personalised predictions of risk, response to treatment and effective lifestyle advice. Given rapid advances in genetic testing technology and a move towards population-level genotyping, these early results have several important implications that promise to revolutionise the way in which glaucoma is detected and managed in years to come.

[Use of antiglaucomatous drugs in the urban adult population : New Insights into the prevalence of glaucoma from the Hamburg City Health Study]

BACKGROUND

Glaucoma is a widespread ophthalmological disease. Knowledge about the spread of the disease in the population is necessary with respect to further questions on comorbidities, risk factors and the provision of care.

OBJECTIVE

An analysis of the use of glaucoma medications and the prevalence of glaucoma in an urban adult population was carried out.

MATERIAL AND METHODS

The Hamburg City Health Study (HCHS) is a prospective, long-term, population-based cohort study that includes a random sample of 45,000 participants aged between 45 and 79 years from the general population of Hamburg, Germany. Apart from various medical parameters, data include premedication and the medical history of the participants. The use of antiglaucomatous medication among the first 10,000 study participants was analyzed and the prevalence of glaucoma was estimated according to the use of medications as well as by the self-reported history of glaucoma. Descriptive analysis and logistic regression analysis were performed to analyze the data and to calculate correlations by age and gender.

RESULTS

In the study population 319 persons were on medication to lower the intraocular pressure (IOP, mean age 67.1 years, SD = 7.57 years), which is equivalent to an estimated prevalence of 3.35% (95% confidence interval, CI 3.00-3.70%). A positive correlation was observed between age and the use of IOP-lowering medication, which is statistically highly significant (p = < 0.001). The analysis by gender showed a slightly higher prevalence among women, which was not statistically significant. The estimated prevalence according to glaucoma medication and history were only partly congruent.

DISCUSSION

This estimated prevalence of glaucoma is comparable to other epidemiological studies. The study results cover not only patients with manifest glaucoma but also persons who were treated for ocular hypertension. The inconsistency between the prevalence of glaucoma medication and the diagnosis of glaucoma can be explained by different treatment strategies and also by information deficits.

[Awareness for glaucoma in the general population]

BACKGROUND

Glaucoma is not a rare entity but because very few symptoms occur and visual field defects are frequently first recognized at a late stage, a large proportion of glaucoma diseases remain undetected. The aim of this study was to identify the proportion of undiagnosed glaucoma in German population-based cohort studies and to contextualize them in the context of the literature.

MATERIAL AND METHODS

The prevalence of glaucoma in the Gutenberg Health Study (GHS) and the age-related investigations on health of the University of Regensburg (AugUR) was evaluated based on visual field examinations and optic disc color photography according to the ISGEO criteria. Furthermore, the self-reported glaucoma diagnoses were collected and the proportion of undiagnosed glaucoma was determined.

RESULTS

The proportion of undiagnosed glaucoma was 55% in the GHS, and 53% in the AugUR study. The results correlate with results from previous studies from other countries in which the proportion of unrecognized glaucoma ranged from 33% to 78%. In the GHS and the AugUR study the proportion of undiagnosed glaucoma was higher in younger age groups and in women.

DISCUSSION

Roughly every second case of glaucoma is undetected. As the symptoms are often nonspecific or take a long time to appear, there is a risk of advanced glaucomatous visual field defects or blindness due to a lack of glaucoma awareness. Studies have shown that a systematic screening can halve this risk.

A Systematic Review of Glaucoma Diagnosis in Prevalence Studies and Quality of Reporting

PRCIS

This systematic review has revealed that variable definitions of glaucoma continue to be used in prevalence studies, despite the introduction of the International Society of Geographic and Epidemiologic Ophthalmology (ISGEO) criteria.

PURPOSE

To systematically review diagnostic criteria and examinations performed in glaucoma prevalence studies over time and determine the quality of reporting. Accurate estimates of glaucoma prevalence are crucial to inform resource allocation. However, diagnosis of glaucoma comprises inherently subjective examinations and the cross-sectional nature of prevalence studies precludes monitoring for progression.

METHODS

A systematic review of PubMed, Embase, Web of Science, and Scopus was performed to examine diagnostic protocols used by glaucoma prevalence studies and evaluate uptake of the ISGEO criteria, introduced in 2002 to standardize glaucoma diagnosis in prevalence studies. Detection bias and compliance with the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) guidelines were evaluated.

RESULTS

Ten thousand five hundred forty-four articles were identified. After deduplication, 5589 articles were screened, yielding 136 articles pertaining to 123 studies. An absence of data in many countries was identified. Ninety-two percent of studies stated diagnostic criteria, and 62% used the ISGEO criteria since their publication. Weaknesses of the ISGEO criteria were identified. Temporal variations in the performance of various examinations were observed, including heterogeneity in angle assessment. Mean STROBE compliance was 82% (range 59-100%); 72 articles had a low risk of detection bias, 4 had a high risk, and 60 had some concerns.

CONCLUSION

Heterogeneous diagnostic definitions persist in glaucoma prevalence studies, despite introduction of the ISGEO criteria. Standardization of criteria remains imperative and the development of new criteria represent a valuable opportunity to achieve this goal. In addition, methods of determining diagnoses are poorly reported, suggesting a need for improvement in study conduct and reporting. Accordingly, we propose the Reporting of quality Of GlaUcoma Epidemiological Studies (ROGUES) Checklist. We have also identified a need for further prevalence studies in regions with limited data and to update Australian angle closure glaucoma prevalence. Design and reporting of future studies can be informed by this review's insights into diagnostic protocols previously used.

Intraocular Pressure Variations in Postural Changes: Comparison between Obese and Non-Obese Controls

BACKGROUND

Comparing intraocular pressure (IOP) changes (ΔIOP) between obese subjects and non-obese controls in relation to different positions: standing, sitting, supine.

METHODS

the IOP was measured in both obese patients and non-obese controls groups with Tono-Pen AVIA in different positions following this sequence: after 5 min (5') in the standing position, sitting, supine, supine after 5 min (supine 5') and immediately after standing. ΔIOP values obtained comparing all positions were, therefore, evaluated.

RESULTS

92 eyes of 46 obese subjects aged between 18 and 59 years (mean 38.07 ± 11.51 years) and of a Body Mass Index (BMI) between 31.84 and 60.65 (mean 41.84 ± 7.05) were evaluated. A total of 48 eyes of 24 non-obese controls aged between 23 and 55 (mean 35.21 ± 11.96 years) and of a BMI between 18.20 and 26.79 (mean 21.04 ± 2.36) were also recruited. In obese subjects, there were statistically significant differences between the IOP in the supine position and the supine positions 5' with all other IOP measurements (p < 0.05). There were statistically significant differences between ΔIOP in both supine positions and prolonged standing positions obtained by obese subjects and non-obese controls (p < 0.05).

CONCLUSIONS

In obese subjects, there is a statistically significant increase in IOP in the supine positions that is significantly greater than the non-obese population. BMI is weakly correlated with IOP and ΔIOP in postural changes.

Optic Nerve Head Changes After Intraocular Pressure-Lowering Glaucoma Surgeries Using Optical Coherence Tomography

PRCIS

Optic nerve head (ONH) changes were detected with swept-source optical coherence tomography (SS-OCT) after intraocular pressure (IOP)-lowering glaucoma surgeries.

PURPOSE

The aim of this study was to detect changes in the ONH with SS-OCT after IOP-lowering procedures.

PATIENTS AND METHODS

Patients with progressing glaucoma who were referred for IOP-lowering procedures were included. The participants underwent a 24-2 visual field test and SS-OCT (DRI OCT Triton Plus; Topcon). IOP and SS-OCT scans were obtained during the preoperative period and up to 7 days and 30-90 days postoperatively. ONH parameters were measured with a B -scan at the center of the optic disc and an average of 5 central B -scans. The hypotenuse of the ONH cup (HOC) was calculated using the Pythagorean theorem: hypotenuse 2 = leg1 2 + leg2 2 , considering the length and depth of the cup as the legs of a right triangle. We also evaluated changes in Bruch membrane opening (BMO)-to-BMO diameter. Statistical analysis was performed using generalized estimating equations.

RESULTS

A total of 15 eyes were included. The mean patient age was 70 (SD, 11.04) years. The mean circumpapillary retinal nerve fiber layer was 60.13 (SD, 23.21) µm and the visual field mean deviation was -13.29 (SD, 8.5) dB. The mean IOP at each visit was: 20.5 (SD, 4.99); 11 (SD, 4.95), and 15.7 (SD, 5.04), respectively. The mean HOC, the mean depth and length of the ONH cup, and the BMO-to-BMO diameter decreased significantly after the IOP-lowering procedures.

CONCLUSIONS

The HOC evaluated with SS-OCT significantly decreased after IOP-lowering surgeries. This parameter was useful for evaluating short-term changes in the ONH.

Study profile: the Genetics of Glaucoma Study

PURPOSE

Glaucoma, a major cause of irreversible blindness, is a highly heritable human disease. Currently, the majority of the risk genes for glaucoma are unknown. We established the Genetics of Glaucoma Study (GOGS) to identify disease genes and improve genetic prediction of glaucoma risk and response to treatment.

PARTICIPANTS

More than 5700 participants with glaucoma or a family history of glaucoma were recruited through a media campaign and the Australian Government healthcare service provider, Services Australia, making GOGS one of the largest genetic studies of glaucoma globally. The mean age of the participants was 65.30±9.36 years, and 62% were female. Participants completed a questionnaire obtaining information about their glaucoma-related medical history such as family history, glaucoma status and subtypes, surgical procedures, and prescriptions. The questionnaire also obtained information about other eye and systemic diseases. Approximately 80% of the participants provided a DNA sample and ~70% consented to data linkage to their Australian Government Medicare and Pharmaceutical Benefits Scheme schedules.

FINDINGS TO DATE

4336 GOGS participants reported that an optometrist or ophthalmologist has diagnosed them with glaucoma and 3639 participants reported having a family history of glaucoma. The vast majority of the participants (N=4393) had used at least one glaucoma-related medication; latanoprost was the most commonly prescribed drug (54% of the participants who had a glaucoma prescription). A subset of the participants reported a surgical treatment for glaucoma including a laser surgery in 2008 participants and a non-laser operation in 803 participants. Several comorbid eye and systemic diseases were also observed; the most common reports were ocular hypertension (53% of the participants), cataract (48%), hypertension (40%), nearsightedness (31%), astigmatism (22%), farsightedness (16%), diabetes (12%), sleep apnoea (11%) and migraines (10%).

FUTURE PLANS

GOGS will contribute to the global gene-mapping efforts as one of the largest genetic studies for glaucoma. We will also use GOGS to develop or validate genetic risk prediction models to stratify glaucoma risk, particularly in individuals with a family history of glaucoma, and to predict clinical outcomes (eg, which medication works better for an individual and whether glaucoma surgery is required). GOGS will also help us answer various research questions about genetic overlap and causal relationships between glaucoma and its comorbidities.

Cell-Based Therapies for Glaucoma

Glaucomatous optic neuropathy (GON) is the major cause of irreversible visual loss worldwide and can result from a range of disease etiologies. The defining features of GON are retinal ganglion cell (RGC) degeneration and characteristic cupping of the optic nerve head (ONH) due to tissue remodeling, while intraocular pressure remains the only modifiable GON risk factor currently targeted by approved clinical treatment strategies. Efforts to understand the mechanisms that allow species such as the zebrafish to regenerate their retinal cells have greatly increased our understanding of regenerative signaling pathways. However, proper integration within the retina and projection to the brain by the newly regenerated neuronal cells remain major hurdles. Meanwhile, a range of methods for in vitro differentiation have been developed to derive retinal cells from a variety of cell sources, including embryonic and induced pluripotent stem cells. More recently, there has been growing interest in the implantation of glial cells as well as cell-derived products, including neurotrophins, microRNA, and extracellular vesicles, to provide functional support to vulnerable structures such as RGC axons and the ONH. These approaches offer the advantage of not relying upon the replacement of degenerated cells and potentially targeting earlier stages of disease pathogenesis. In order to translate these techniques into clinical practice, appropriate cell sourcing, robust differentiation protocols, and accurate implantation methods are crucial to the success of cell-based therapy in glaucoma. Translational Relevance: Cell-based therapies for glaucoma currently under active development include the induction of endogenous regeneration, implantation of exogenously derived retinal cells, and utilization of cell-derived products to provide functional support.

Tissue-engineered anterior segment eye cultures demonstrate hallmarks of conventional organ culture

BACKGROUND

Glaucoma is a blinding disease largely caused by dysregulation of outflow through the trabecular meshwork (TM), resulting in elevated intraocular pressure (IOP). We hypothesized that transplanting TM cells into a decellularized, tissue-engineered anterior segment eye culture could restore the outflow structure and function.

METHODS

Porcine eyes were decellularized with freeze-thaw cycles and perfusion of surfactant. We seeded control scaffolds with CrFK cells transduced with lentiviral vectors to stably express eGFP and compared them to scaffolds seeded with primary TM cells as well as to normal, unaltered eyes. We tracked the repopulation behavior, performed IOP maintenance challenges, and analyzed the histology.

RESULTS

Transplanted cells localized to the TM and progressively infiltrated the extracellular matrix, reaching a distribution comparable to normal, unaltered eyes. After a perfusion rate challenge to mimic a glaucomatous pressure elevation, transplanted and normal eyes reestablished a normal intraocular pressure (transplanted = 16.5 ± 0.9 mmHg, normal = 16.9 ± 0.9). However, eyes reseeded with eGFP-expressing CrFK cells could not regulate IOP, remaining high and unstable (27.0 ± 6.2 mmHg) instead.

CONCLUSION

Tissue-engineered anterior segment scaffolds can serve as readily available, scalable ocular perfusion cultures. This could reduce dependency on scarce donor globes in outflow research and may allow engineering perfusion cultures with specific geno- and phenotypes.

Burden of Glaucoma in the United Kingdom: A Multicenter Analysis of United Kingdom Glaucoma Services

OBJECTIVE

To determine the spectrum of glaucoma-associated health care resource utilization among outpatients attending National Health Service (NHS) hospital glaucoma clinics and the costs of managing glaucoma in this setting.

DESIGN

Retrospective observational cohort study using electronic medical record data.

SUBJECTS

Patients aged ≥ 18 years attending 5 NHS glaucoma clinics in the United Kingdom (2013‒2018) with ≥ 12 months of continuous electronic medical record data.

METHODS

Deidentified Medisoft Ophthalmology electronic medical record data (January 2013‒December 2018) from 43 742 eligible patients were categorized by year of clinic visit. Extracted information included patient demographics, glaucoma diagnoses, topical glaucoma medication prescription start/stop dates, types/numbers of glaucoma clinic visits, glaucoma investigations (visual acuity, intraocular pressure, visual field, and OCT), and glaucoma procedures received over 12 months after the first ("index") visit of the specified year. Direct glaucoma-related health care costs (clinic visits, investigations, procedures, and ongoing glaucoma medication initiated in the clinic) were estimated from event volumes and unit costs (UK national tariffs) and expressed from the direct-payer perspective.

MAIN OUTCOME MEASURES

Glaucoma diagnoses and topical glaucoma medication use at the index clinic visit; numbers of glaucoma clinic visits, investigations and procedures; and glaucoma-related health care costs over 12 months postindex.

RESULTS

For the 2016 cohort (n = 21 719), the estimated average total cost of NHS-provided glaucoma care over 12 months was £405 per patient (medical staff services £209, glaucoma investigations £126, glaucoma medication £40, glaucoma procedures £26). Among this cohort, 40.8% had ocular hypertension/suspected glaucoma, 70% had 0-to-mild visual field impairment, and 14% had undergone a glaucoma procedure. Over 12 months, patients received (mean) 2.0 glaucoma clinic visits and 1.5 visual field tests, and 7% underwent glaucoma procedure(s). Results were similar for the other years examined.

CONCLUSIONS

Cost estimates for managing patients with glaucoma in the UK are required for effective service planning. Appreciable proportions of patients managed in NHS glaucoma clinics may be considered at low risk of blindness (glaucoma suspects and those with ocular hypertension with mild visual field loss) and may be more appropriately managed with alternative, more affordable models of care.

Estimating the Length of the Preclinical Detectable Phase for Open-Angle Glaucoma

Importance

A 50% reduction of glaucoma-related blindness has previously been demonstrated in a population that was screened for open-angle glaucoma. Ongoing screening trials of high-risk populations and forthcoming low-cost screening methods suggest that such screening may become more common in the future. One would then need to estimate a key component of the natural history of chronic disease, the mean preclinical detectable phase (PCDP). Knowledge of the PCDP is essential for the planning and early evaluation of screening programs and has been estimated for several types of cancer that are screened for.

Objective

To estimate the mean PCDP for open-angle glaucoma.

Design, Setting, and Participants

A large population-based screening for open-angle glaucoma was conducted from October 1992 to January 1997 in Malmö, Sweden, including 32 918 participants aged 57 to 77 years. A retrospective medical record review was conducted to assess the prevalence of newly detected cases at the screening, incidence of new cases after the screening, and the expected clinical incidence, ie, the number of new glaucoma cases expected to be detected without a screening. The latter was derived from incident cases in the screened age cohorts before the screening started and from older cohorts not invited to the screening. A total of 2029 patients were included in the current study. Data were analyzed from March 2020 to October 2021.

Main Outcomes and Measures

The length of the mean PCDP was calculated by 2 different methods: first, by dividing the prevalence of screen-detected glaucoma with the clinical incidence, assuming that the screening sensitivity was 100% and second, by using a Markov chain Monte Carlo (MCMC) model simulation that simultaneously derived both the length of the mean PCDP and the sensitivity of the screening.

Results

Of 2029 included patients, 1352 (66.6%) were female. Of 1420 screened patients, the mean age at screening was 67.4 years (95% CI, 67.2-67.7). The mean length of the PCDP of the whole study population was 10.7 years (95% CI, 8.7-13.0) by the prevalence/incidence method and 10.1 years (95% credible interval, 8.9-11.2) by the MCMC method.

Conclusions and Relevance

The mean PCDP was similar for both methods of analysis, approximately 10 years. A mean PCDP of 10 years found in the current study allows for screening with reasonably long intervals, eg, 5 years.

Goldmann and modified Goldmann tonometry measuring intraocular pressure changes in eyes which underwent myopic laser in situ Keratomileusis and photorefractive keratectomy

PURPOSE

Compare intraocular pressure (IOP) measured by a standard Goldmann applanation tonometer prism (IOPg) and a modified correcting applanation tonometer surface Goldmann prism (IOPc) before and after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

METHODS

Goldmann tonometry was analyzed in a retrospective, cross-sectional study, using both GAT and modified-GAT prisms pre-operatively and at the 3 month post-operative appointment on 120 eyes (64 patients) who received LASIK (n = 58) or PRK (n = 62). Demographics, central corneal thickness (CCT), manifest refraction and corneal curvature (CC) data was collected at each visit as well as surgical parameters, including maximum ablation depth.

RESULTS

Mean paired IOP following LASIK decreased by - 3.28 ± 3.2 mmHg measured by IOPg and - 1.93 ± 3.3 mmHg by IOPc (p ≤ 0.0001). Mean paired IOP following PRK reduced by - 1.92 ± 3.6 mmHg measured by IOPg and - 1.06 ± 3.6 mmHg by IOPc (p ≤ 0.0001). Increased LASIK ablation depth and post-procedural change in CCT trended toward a statistically significant reduction in IOPg (p = 0.07,p = 0.12), but not IOPc (p = 0.18,p = 0.32). PRK ablation depth was not associated with a reduction in IOPg or IOPc.

DISCUSSION

The modified Goldmann (IOPc) prism measured less of an IOP reduction following LASIK and PRK compared to the standard (IOPg) prism, and the IOP reduction with both prisms was associated with the degree of myopic correction.

WHAT IS ALREADY KNOWN AND THE RESIDUAL QUERY

Corneal refractive surgery generally demonstrates significant postoperative Goldmann IOP reductions. Presumably, this is due to corneal biomechanical changes for which a newer method of Goldmann IOP measurement may be able to compensate.

WHAT THIS STUDY ADDS

A modified, corneal conforming Goldmann prism demonstrates significantly less IOP reduction following myopic LASIK and PRK compared to the standard flat Goldmann prism.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

A newer, modified Goldmann prism may help detect glaucoma and OHT at an earlier stage in patients which have undergone LASIK or PRK. The findings corroborate predicted corneal biomechanical changes following the most common corneal refractive procedures.

Risk factors for previously undiagnosed primary open-angle glaucoma: the EPIC-Norfolk Eye Study

BACKGROUND AND AIM

Undiagnosed glaucoma is an invisible but important public health issue. At least half of glaucoma cases are estimated to be undiagnosed in western populations. The aim of this study is to examine risk factors for previously undiagnosed primary open-angle glaucoma (POAG).

DESIGN

Cross-sectional study within the European Prospective Investigation of Cancer-Norfolk Eye Study, a large-scale cohort study in the UK.

PARTICIPANTS

314 study participants with POAG in either eye.

METHODS

Logistic regression was used to examine associations with previously undiagnosed POAG compared with previously diagnosed POAG. The factors examined included sociodemographic, ocular, physical and economic factors that could be barriers to eye care access.

RESULTS

217 participants had previously diagnosed POAG and 107 participants were newly diagnosed with POAG during the study. After adjusting for covariables, the factors significantly associated with previously undiagnosed POAG were: a lower pretreatment intraocular pressure (IOP) (OR 0.71/mm Hg, 95% CI 0.63 to 0.80, p<0.0001), and to have reported no problems with their eyesight (OR 0.03, 95% CI 0.01 to 0.10, p<0.0001).

CONCLUSIONS

The risk factors for previously undiagnosed POAG identified in this study highlight the over-reliance on IOP level in glaucoma screening and the risk of missing glaucoma among lower IOP cases. It also suggests a role in improving glaucoma awareness in the community.

Whole-exome sequencing study identifies rare variants and genes associated with intraocular pressure and glaucoma

Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, the leading cause of irreversible blindness worldwide. IOP is also the only modifiable risk factor for glaucoma. Previous genome-wide association studies have established the contribution of common genetic variants to IOP. The role of rare variants for IOP was unknown. Using whole exome sequencing data from 110,260 participants in the UK Biobank (UKB), we conducted the largest exome-wide association study of IOP to date. In addition to confirming known IOP genes, we identified 40 novel rare-variant genes for IOP, such as BOD1L1, ACAD10 and HLA-B, demonstrating the power of including and aggregating rare variants in gene discovery. About half of these IOP genes are also associated with glaucoma phenotypes in UKB and the FinnGen cohort. Six of these genes, i.e. ADRB1, PTPRB, RPL26, RPL10A, EGLN2, and MTOR, are drug targets that are either established for clinical treatment or in clinical trials. Furthermore, we constructed a rare-variant polygenic risk score and showed its significant association with glaucoma in independent participants (n = 312,825). We demonstrated the value of rare variants to enhance our understanding of the biological mechanisms regulating IOP and uncovered potential therapeutic targets for glaucoma.

Assessing Corneal Endothelial Damage Using Terahertz Time-Domain Spectroscopy and Support Vector Machines

The endothelial layer of the cornea plays a critical role in regulating its hydration by actively controlling fluid intake in the tissue via transporting the excess fluid out to the aqueous humor. A damaged corneal endothelial layer leads to perturbations in tissue hydration and edema, which can impact corneal transparency and visual acuity. We utilized a non-contact terahertz (THz) scanner designed for imaging spherical targets to discriminate between ex vivo corneal samples with intact and damaged endothelial layers. To create varying grades of corneal edema, the intraocular pressures of the whole porcine eye globe samples (n = 19) were increased to either 25, 35 or 45 mmHg for 4 h before returning to normal pressure levels at 15 mmHg for the remaining 4 h. Changes in tissue hydration were assessed by differences in spectral slopes between 0.4 and 0.8 THz. Our results indicate that the THz response of the corneal samples can vary according to the differences in the endothelial cell density, as determined by SEM imaging. We show that this spectroscopic difference is statistically significant and can be used to assess the intactness of the endothelial layer. These results demonstrate that THz can noninvasively assess the corneal endothelium and provide valuable complimentary information for the study and diagnosis of corneal diseases that perturb the tissue hydration.

Potential for Collider Bias in Studies Examining the Association of Central Corneal Thickness With Glaucoma

Purpose

Central corneal thickness (CCT) may be biologically related to glaucoma or observed as associated with glaucoma simply due to its effect on intraocular pressure (IOP) measurement. We aimed to determine if the previously reported CCT-glaucoma associations, in which the analyses were adjusted for IOP or participants were selected on IOP, could be explained by collider bias.

Methods

We simulated datasets mimicking a longitudinal population-based study (Los Angeles Latino Eye Study) and a trial (Ocular Hypertension Treatment Study) such that: (i) CCT was not truly associated with glaucoma, (ii) CCT and true IOP both contribute to measured IOP, and (iii) true IOP contributes to glaucoma risk. We then tested whether an association between CCT and glaucoma could be spuriously induced simply by adjusting for or selecting on measured IOP.

Results

A thinner CCT was significantly associated with higher glaucoma incidence in the simulated longitudinal population-based study when adjusted for measured IOP, but not crudely (unadjusted). A thinner CCT was crudely associated with glaucoma incidence in the simulated trial in which the participants were selected for high measured IOP. Effect sizes in the simulations were similar to those observed in the original studies.

Conclusions

Our findings question whether CCT is biologically associated with glaucoma and suggest that current evidence may be due to collider bias. This indicates that CCT alone cannot be used as a factor to identify people at high risk of glaucoma in the general population. Using CCT in combination with IOP may be superior to using IOP alone.

Risk of Missed Diagnosis of Primary Open-Angle Glaucoma by Eye Care Providers

Purpose

To evaluate the efficacy of opportunistic case finding in glaucoma detection and to determine factors associated with failure of glaucoma detection by eye health providers.

Methods

This study was conducted on 154 new definite primary open-angle glaucoma (POAG) patients presenting to our glaucoma clinic. A questionnaire was prepared to determine if these subjects had sought eye care up to 12 months before presentation. The type of eye care provider and the principal reason for the visit were probed. The primary outcome measure was the frequency of a correct glaucoma diagnosis in their index visit. The secondary outcomes were factors associated with missed POAG diagnosis.

Results

The great majority of study subjects (132 cases, 85.7%) had sought at least one ocular examination within 1 year before presentation. Among these patients, 73 cases (55.3%) had remained undiagnosed after the examination. Among the probed variables, age, gender, visual acuity, visual field defects, intraocular pressure, cup/disc ratio, nerve fiber layer thickness of the worse eye at presentation, and family history of glaucoma were comparable between correctly diagnosed and missed POAGs. The only factors significantly associated with missed POAG diagnosis were lack of significant refractive errors and visiting an optometrist rather than an ophthalmologist.

Conclusions

The efficacy of opportunistic case finding for POAG seems to be less than ideal in our settings. Lack of a significant refractive error and visiting an optometrist rather than an ophthalmologist were associated with a missed diagnosis of POAG. These observations reflect the need to adopt policies to improve glaucoma screening by eye care providers.

Association of Exercise Intensity with the Prevalence of Glaucoma and Intraocular Pressure in Men: A Study Based on the Korea National Health and Nutrition Examination Survey

Adequate exercise is essential for maintaining a healthy lifestyle and preventing ageing-related diseases. The purpose of this study was to assess the associations between exercise and glaucoma, as well as exercise and intraocular pressure (IOP) levels. This study used data from the Korea National Health and Nutrition Examination Surveys 2008–2012, which in total included 10,243 men aged ≥40 years. The presence of glaucoma and the higher IOP of each eye (IOPmax) taken from the health examination survey and the ophthalmic examination were used for analyses. A questionnaire was used to assess exercise activity, which was analysed regarding intensity, frequency, and duration. Regression analyses were used to determine the relationships of exercise parameters with the odds of glaucoma and IOPmax. The prevalence of glaucoma was significantly lower in men who engaged in moderate-to-vigorous intensity exercise compared to those who did not exercise (p = 0.012). The odds for glaucoma were the lowest in men engaged in vigorous intensity exercise (p = 0.009). However, IOPmax was highest in the vigorous intensity exercise group (p = 0.026) with no linear trend pattern. These results suggest that exercise decreased the odds of glaucoma via several factors including non-IOP mechanisms.

High Blood Pressure and Intraocular Pressure: A Mendelian Randomization Study

Purpose

To test for causality with regard to the association between blood pressure (BP) and intraocular pressure (IOP) and glaucoma.

Methods

Single nucleotide polymorphisms (SNPs) associated with BP were identified in a genome-wide association study (GWAS) meta-analysis of 526,001 participants of European ancestry. These SNPs were used to assess the BP versus IOP relationship in a distinct sample (n = 70,832) whose corneal-compensated IOP (IOPcc) was measured. To evaluate the BP versus primary open-angle glaucoma (POAG) relationship, additional Mendelian randomization (MR) analyses were conducted using published GWAS summary statistics.

Results

Observational analysis revealed a linear relationship between BP traits and IOPcc, with a +0.28 mm Hg increase in IOPcc per 10-mm Hg increase in systolic BP (95% confidence interval [CI], 0.26-0.29); for diastolic blood pressure (DBP) and pulse pressure (PP), these estimates were +0.41 mm Hg and +0.36 mm Hg, respectively. An inverse-variance weighted MR analysis did not support a causal relationship, as the estimated causal effect was +0.01 mm Hg IOPcc per 10-mm Hg increase in systolic blood pressure (SBP); +0.13 mm Hg IOPcc per 10-mm Hg increase in DBP; and +0.02 mm Hg IOPcc per 10-mm Hg increase in PP (all P > 0.05). With regard to the risk of POAG, MR analyse yielded causal effect estimate of odds ratio = 0.98 (95% CI, 0.92-1.04) per 10-mm Hg increase in SBP. Neither DBP nor PP demonstrated evidence of a causal effect on POAG.

Conclusions

A range of different MR analysis methods provided evidence, in general, that the causal effect of BP on IOP (and POAG) was modest, or even zero. However, interpretation was complicated by SNPs associated with BP potentially having pleiotropic effects on IOP.

Screening for Glaucoma in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Two 2013 systematic reviews to inform the US Preventive Services Task Force (USPSTF) found insufficient evidence to assess benefits and harms of screening for primary open-angle glaucoma (OAG) in adults.

OBJECTIVE

To update the 2013 reviews on screening for glaucoma, to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews (to February 2021); surveillance through January 21, 2022.

STUDY SELECTION

Randomized clinical trials (RCTs) of screening, referral, and treatment; and studies of screening test diagnostic accuracy.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data and a second checked accuracy. Two investigators independently assessed study quality.

RESULTS

Eighty-three studies (N = 75 887) were included (30 trials and 53 diagnostic accuracy studies). One RCT (n = 616) found screening of frail elderly persons associated with no difference in vision outcomes vs no screening but with significantly greater falls risk (relative risk [RR], 1.31 [95% CI, 1.13-1.50]). No study evaluated referral to an eye health professional. For glaucoma diagnosis, spectral domain optical coherence tomography (providing high-resolution cross-sectional imaging; 15 studies, n = 4242) was associated with sensitivity of 0.79 (95% CI, 0.75-0.83) and specificity of 0.92 (95% CI, 0.87-0.96) and the Humphrey Visual Field Analyzer (for perimetry, or measurement of visual fields; 6 studies, n = 11 244) with sensitivity of 0.87 (95% CI, 0.69-0.95) and specificity 0.82 (95% CI, 0.66-0.92); tonometry (for measurement of intraocular pressure; 13 studies, n = 32 892) had low sensitivity (0.48 [95% CI, 0.31-0.66]). Medical therapy for ocular hypertension and untreated glaucoma was significantly associated with decreased intraocular pressure and decreased likelihood of glaucoma progression (7 trials, n = 3771; RR, 0.68 [95% CI, 0.49-0.96]; absolute risk difference -4.2%) vs placebo, but 1 trial (n = 461) found no differences in visual acuity, quality of life, or function. Selective laser trabeculoplasty and medical therapy had similar outcomes (4 trials, n = 957).

CONCLUSIONS AND RELEVANCE

This review found limited direct evidence on glaucoma screening, showing no association with benefits. Screening tests can identify persons with glaucoma and treatment was associated with a lower risk of glaucoma progression, but evidence of improvement in visual outcomes, quality of life, and function remains lacking.

Clinical Audit on the Effectiveness of Clinic-Based Intraocular Pressure Phasing for Patients With Glaucoma and Glaucoma Suspect

INTRODUCTION

Glaucoma is a complex disease with intraocular pressure (IOP) playing an important role in its diagnosis and management. IOP has shown diurnal and nocturnal variations, which may affect the course of the disease.

OBJECTIVE

The objective of this study was to determine the effectiveness of clinic-based office hour phasing in the diagnosis and management of glaucoma and glaucoma suspect (GS).

METHODS

A retrospective clinical audit was conducted on patients who were subjected to office hour phasing in a glaucoma clinic, Hospital Universiti Sains Malaysia, Kelantan, Malaysia, between January 2015 and December 2019. The office hour phasing was conducted for various indications such as confirmation of diagnosis, screening, and effectiveness of treatment. IOP was recorded every two hours between 0800 and 1600 using an air puff tonometer by a trained nurse. Measurement of IOP was repeated with Goldmann applanation tonometer at sitting position by a trainee when the IOP ≥ 20 mmHg or discrepancy of IOP > 2 mmHg between two eyes. Other investigations including a Humphrey visual field and gonioscopy were conducted in between the IOP measurements. Diagnosis and clinical decisions on management were made at the end of the office hour clinic phasing.

RESULTS

A total of 83 patients (163 eyes) were included in this clinical audit. Their mean age was 59.3 (16.5) years with 59% of male patients. Both eyes showed an almost similar pattern of mean IOP over five daytime readings in the clinic. A total of 35 eyes (21.5%) showed fluctuation ≥ 6 mmHg, and 128 eyes (78.5%) showed stable IOP during the clinic hour phasing. There was a significant difference in the mean IOP pattern between groups with stable and fluctuating IOP based on repetitive measure analysis of variance (RM ANOVA) (p = 0.008). The final diagnosis was made for 39 eyes (21 OD [right eye] and 18 OS [left eye]) out of 131 eyes (29.8%) with GS. Confirmation of diagnosis was achieved in all eyes (100%) with suspected ocular hypertension (OHT) and normal-tension glaucoma (NTG). Progression of glaucoma was confirmed in four eyes (2 OD and 2 OS) out of 17 eyes (23.5%) with suspected progression.

CONCLUSION

Clinic hour IOP phasing provides a practical approach in confirmation of diagnosis and adjustment in the management of patients with glaucoma and GS.

Corneal-compensated intraocular pressure, Goldmann-correlated intraocular pressure and their associated factors in the geriatric population, a population-based study

PURPOSE

To determine the distribution of corneal-compensated intraocular pressure (IOPcc), Goldmann-correlated intraocular pressure (IOPg) and their associated factors in a geriatric population.

METHODS

The present cross-sectional study was performed in individuals above 60 years of age in Tehran, the capital of Iran. The sampling was performed using multi-stage random cluster sampling method. All participants underwent preliminary ocular examinations, and then imaging by Pentacam HR and IOL master 500. Measurement of IOPg, IOPcc, and corneal biomechanical indices including corneal hysteresis (CH) and corneal resistant factor (CRF) was performed in a random sub-sample using ocular response analyzer (ORA).

RESULTS

The mean IOPg and IOPcc were 16.76 ± 4.71 mmHg and 19.05 ± 4.67 mmHg, respectively. There were no statistically significant differences in both IOPg (p = 0.891) and IOPcc (p = 0.248) between males and females. Based on the multiple linear regression models, both IOPg and IOPcc showed a statistically significant direct relationship with CRF (P < 0.001) and a significant inverse relationship with CH (P < 0.001 for IOPg and IOPcc), anterior chamber angle (ACA) (p = 0.006 for IOPg and p = 0.017 for IOPcc), and spherical equivalent refractive error (p = 0.032 for IOPg and p = 0.046 for IOPcc).

CONCLUSION

Mean IOPg and IOPcc in the present study were higher compared to most previous studies. Corneal biomechanical indices including CH and CRF, refractive error and anterior chamber angle were independent associated factors of IOPg and IOPcc in the present study. There was no significant relationship between ORA-derived IOP values and CCT.

Cost effectiveness analysis associated to the treatment of primary open-angle glaucoma according to disease severity

Introduction/Objective. POAG treatment should be individually tailored to the disease severity and type, effectiveness and secondary side effects of the medications used. This research aimed to assess the direct medical costs and the cost effectiveness associated with pharmacotherapy in visually impaired people with primary open-angle glaucoma according to disease severity. Methods. This scientific study is designed as an observational cross-sectional study with a quantitative analytical approach and was conducted in the period from July 2020 to June 2021 on the territory of North Macedonia. The study included 157 patients with binocular POAG in the early, moderate and advanced clinical stage, up to the age of 67, with changes in visual acuity and work ability. During the assessment of the effects of pharmacotherapy were analyzed the types, mutual correlations and effectiveness of the most commonly prescribed antiglaucomatous medications and the cost benefit from their administration. Direct medical costs are calculated according to disease severity in the last 12 months using real-time data of public interest. Results. The beta blockers due to their affordable price and availability are the dominant option with high-cost benefit for primary treatment of POAG. Antiglaucoma medications and diagnostic procedures are major components of direct medical treatment costs. Conclusion. Pharmacotherapy is the dominant alternative compared to other types of treatment because it is safer and is associated with greater effictiveness and lower direct medical costs.

Glaucoma and its predictors among adult patients attending ophthalmic outpatient department: a hospital-based study, North West Ethiopia

BACKGROUND

Nearly 1.9% of global blindness is caused by glaucoma and this is sadly high in Africa which is around 15% and In Ethiopia, glaucoma is responsible for 5.2% of blindness. It is also the fifth cause of blindness in Ethiopia. Scarce information is available regarding glaucoma in Ethiopia; hence we determined the proportion of glaucoma and its associated factors in North West Ethiopia which will be utilized for future related researches and different stakeholders.

METHODS

Institution based cross-sectional study was conducted from September 1/2020 to February 30/21 among 258 adults aged 40 and above years old. The participants were selected using the systematic random sampling technique. The data was collected using an interview-administered questionnaire. Binary and Multi-variable logistic regressions were fitted to identify independent predictors of glaucoma. P-value less than 0.05 were used as a cutoff point for declaring statistical significance.

RESULTS

The prevalence of glaucoma was 66(26%) with a 95% CI of 17.7, 35.4%). Individuals with Positive family history of glaucoma (AOR: 3.72, 95% CI: 1.03-3.53), age (AOR: 3.21, 95% CI: 1.92-5.99) and elevated intraocular pressure (AOR: 3.09, 95% CI: 1.45-6.59) were statistically significant contributing factors for the development of glaucoma.

CONCLUSION

The study found a relatively high proportion of glaucoma in the study area, which is primarily a disease of the elderly. Age, elevated intraocular pressure, and positive family history of glaucoma was contributing factors for the emergence of glaucoma. Therefore, establishing public awareness programs about the identified risk factors for the prevention and early detection of cases is essential.

A prospective study on effectiveness of elevated intraocular pressure as a criterion for glaucoma referrals by optometric practitioners in Sweden

PURPOSE

To evaluate the outcome of referrals for suspected glaucoma based on elevated intraocular pressure (IOP) made by optometric practitioners in Sweden.

METHODS

This prospective study included 95 individuals referred to the Skåne University Hospital Malmö, Sweden, during 2019, by optometric practitioners, based on elevated IOP. Positive outcome was defined as a diagnosis of glaucoma, or a diagnosis of suspected glaucoma. Referral accuracy was analysed. Positive predictive values (PPV) of different hypothetical IOP and age thresholds were calculated.

RESULTS

In 34% (95% CI: 24-43%) of the referrals, no eye disease was found. Intraocular pressure (IOP) was the only referral criterion in 77% (73/95). The PPV was 35% (95% CI: 25-45%) for all referrals, 27% (95% CI: 16-38%) for IOP-only referrals and 59% (95% CI: 36-82%) for referrals including additional findings. In IOP-only referrals, no definite diagnosis of glaucoma was made in any patients <45 years of age. Applying a theoretical age limit of ≥45 years with a hypothetical IOP limit of ≥25 mmHg in patients 45-69 years and of ≥22 mmHg in patients ≥70 years increased the PPV to 42% (95% CI: 27-57%). IOP-only referrals would have been reduced by 27% without missing any glaucoma cases.

CONCLUSION

The overall predictive value of the referrals was poor. Glaucoma resources would have been used more effectively by increasing the required age for IOP-only referrals to ≥45 years in combination with different IOP thresholds for certain age groups.

1α,25-dihydroxyvitamin D3 protects retinal ganglion cells in glaucomatous mice

BACKGROUND

Glaucoma is an optic neuropathy characterized by loss of function and death of retinal ganglion cells (RGCs), leading to irreversible vision loss. Neuroinflammation is recognized as one of the causes of glaucoma, and currently no treatment is addressing this mechanism. We aimed to investigate the anti-inflammatory and neuroprotective effects of 1,25(OH)2D3 (1α,25-dihydroxyvitamin D3, calcitriol), in a genetic model of age-related glaucomatous neurodegeneration (DBA/2J mice).

METHODS

DBA/2J mice were randomized to 1,25(OH)2D3 or vehicle treatment groups. Pattern electroretinogram, flash electroretinogram, and intraocular pressure were recorded weekly. Immunostaining for RBPMS, Iba-1, and GFAP was carried out on retinal flat mounts to assess retinal ganglion cell density and quantify microglial and astrocyte activation, respectively. Molecular biology analyses were carried out to evaluate retinal expression of pro-inflammatory cytokines, pNFκB-p65, and neuroprotective factors. Investigators that analysed the data were blind to experimental groups, which were unveiled after graph design and statistical analysis, that were carried out with GraphPad Prism. Several statistical tests and approaches were used: the generalized estimated equations (GEE) analysis, t-test, and one-way ANOVA.

RESULTS

DBA/2J mice treated with 1,25(OH)2D3 for 5 weeks showed improved PERG and FERG amplitudes and reduced RGCs death, compared to vehicle-treated age-matched controls. 1,25(OH)2D3 treatment decreased microglial and astrocyte activation, as well as expression of inflammatory cytokines and pNF-κB-p65 (p < 0.05). Moreover, 1,25(OH)2D3-treated DBA/2J mice displayed increased mRNA levels of neuroprotective factors (p < 0.05), such as BDNF.

CONCLUSIONS

1,25(OH)2D3 protected RGCs preserving retinal function, reducing inflammatory cytokines, and increasing expression of neuroprotective factors. Therefore, 1,25(OH)2D3 could attenuate the retinal damage in glaucomatous patients and warrants further clinical evaluation for the treatment of optic neuropathies.

Differentiating Diagnosed and Undiagnosed Primary Angle-Closure Glaucoma and Open-Angle Glaucoma: A Population-Based Study

PURPOSE

To study and compare factors contributing to the differentiation between diagnosed and undiagnosed primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) in the same population.

DESIGN

Population-based survey.

PARTICIPANTS

All residents 40 years of age and older in Kumejima, Japan.

METHODS

Primary angle-closure glaucoma and POAG were diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology. Factors contributing significantly to the differentiation between diagnosed and undiagnosed PACG and POAG were selected from various systemic, ocular, visual function, and fundus planimetric parameters using multivariate logistic regression analysis and were compared between the two diseases.

MAIN OUTCOME MEASURES

Factors contributing significantly to the differentiation between diagnosed and undiagnosed PACG and POAG.

RESULTS

The prevalence rates of PACG and POAG were 2.2% and 4.0%, respectively. A greater proportion of patients with PACG (34.1%) received a diagnosis previously compared with patients with POAG (17.2%; P = 0.004). Worse mean deviation on visual field (VF) testing (odds ratio, 0.869; 95% confidence interval, 0.788-0.959; P = 0.006) and the presence of signs suggestive of previous acute angle closure (odds ratio, 4.35; range, 1.66-11.36; P = 0.003) contributed to a established diagnosis of PACG at the time of screening. A greater vertical cup-to-disc ratio (3.74; range, 1.38-10.17; P = 0.012) contributed with marginal significance to an established diagnosis of POAG at the time of screening.

CONCLUSIONS

Primary angle-closure glaucoma was more likely to have been diagnosed previously than POAG during a screening examination. Examination of the anterior segment and VF may contribute more to the detection of PACG, and disc examination may contribute more to the detection of POAG.

Large-scale machine-learning-based phenotyping significantly improves genomic discovery for optic nerve head morphology

Genome-wide association studies (GWASs) require accurate cohort phenotyping, but expert labeling can be costly, time intensive, and variable. Here, we develop a machine learning (ML) model to predict glaucomatous optic nerve head features from color fundus photographs. We used the model to predict vertical cup-to-disc ratio (VCDR), a diagnostic parameter and cardinal endophenotype for glaucoma, in 65,680 Europeans in the UK Biobank (UKB). A GWAS of ML-based VCDR identified 299 independent genome-wide significant (GWS; p ≤ 5 × 10-8) hits in 156 loci. The ML-based GWAS replicated 62 of 65 GWS loci from a recent VCDR GWAS in the UKB for which two ophthalmologists manually labeled images for 67,040 Europeans. The ML-based GWAS also identified 93 novel loci, significantly expanding our understanding of the genetic etiologies of glaucoma and VCDR. Pathway analyses support the biological significance of the novel hits to VCDR: select loci near genes involved in neuronal and synaptic biology or harboring variants are known to cause severe Mendelian ophthalmic disease. Finally, the ML-based GWAS results significantly improve polygenic prediction of VCDR and primary open-angle glaucoma in the independent EPIC-Norfolk cohort.

12-month clinical outcomes of combined phacoemulsification and ab interno trabeculectomy for open-angle glaucoma in the United Kingdom

BACKGROUND/OBJECTIVES

To describe intraocular pressure (IOP) and ocular hypotensive medication outcomes of combined phacoemulsification and ab interno trabeculectomy with the Kahook Dual Blade (KDB; New World Medical, Inc, Rancho Cucamonga, CA) in adults with cataract and open-angle glaucoma (OAG).

SUBJECTS/METHODS

Retrospective chart review of existing medical records. Data collected included intraocular pressure (IOP) and IOP-lowering medication use preoperatively and through up to 24 months postoperatively. Paired t-tests were utilized to compare preoperative to postoperative mean IOP and mean medications used.

RESULTS

Data from 32 eyes of 26 subjects were analyzed. Subjects were predominantly Caucasian (25/26) had mean (standard error) age of 79.3 (1.2) years, and eyes had moderate-advanced OAG (mean visual field mean deviation -8.3 [1.3] dB). Mean IOP was 19.8 (0.8) mmHg at baseline and 15.5 (0.6) mmHg (p<0.0001) after mean follow-up of 11.5 (1.0) months; IOP reductions of ≥20% were achieved in 20/32 eyes (62.5%). Mean medication use declined from 2.4 (0.2) medications per eye at baseline to 0.5 (0.2) at last follow-up (p<0.0001); 23/32 eyes (71.9%) were medication-free at last follow-up. No vision-threatening complications were observed.

CONCLUSIONS

Combined phacoemulsification and ab interno trabeculectomy with the KDB safely provided mean IOP reductions of 21.7% and mean IOP medication reductions of 83% after mean follow-up of 12 months in eyes with moderate to advanced OAG. This procedure provides medication-independence in most eyes with statistically and clinically significant IOP reductions.

Non-contact terahertz spectroscopic measurement of the intraocular pressure through corneal hydration mapping

Elevated intraocular pressure (IOP) results in endothelial layer damage that can induce corneal hydration perturbations. We investigated the potential of terahertz spectroscopy in measuring the IOP levels through mapping corneal water content. We controlled the IOP levels in ex vivo rabbit and porcine eye samples while monitoring the change in corneal hydration using a terahertz time-domain spectroscopy (THz-TDS) scanner. Our results showed a statistically significant increase in the THz reflectivity between 0.4 and 0.6 THz corresponding to the increase in the IOP. Endothelial layer damage was confirmed using scanning electron microscopy (SEM) of the corneal biopsy samples. Our empirical results indicate that the THz-TDS can be used to track IOP levels through the changes in corneal hydration.

Genetic Determinants of Intraocular Pressure

Intraocular pressure (IOP) is the cardinal and only modifiable risk factor for glaucoma, the leading cause of irreparable blindness worldwide. Twin and family studies estimate the heritability of IOP to be 40-70%, and linkage studies for IOP have identified numerous loci. Mutations in MYOC can cause markedly elevated IOP and aggressive glaucoma often requiring surgical intervention. However, the majority of the genetic basis for raised IOP and glaucoma in populations is complex, and recent large genome-wide association studies (GWASs) have identified over 100 common variants that contribute to IOP variation. In combination, these loci are predictive for primary open-angle glaucoma in independent populations, achieving an area under the receiver operating characteristic curve of 76% for high-pressure primary open-angle glaucoma; this suggests the possibility of targeted screening in the future. Additionally, GWAS findings have identified important biological pathways underlying IOP regulation, including lymphangiogenesis and lipid metabolism, providing novel targets for new therapies. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Predicting the Future of Genetic Risk Profiling of Glaucoma: A Narrative Review

Importance

Glaucoma is the world's leading cause of irreversible blindness. Primary open-angle glaucoma (POAG) is typically asymptomatic early in the disease process, and unfortunately, many are diagnosed too late to prevent vision loss.

Observations

Genome-wide association studies, which evaluate the association between genetic variants and phenotype across the genome, have mapped many genes for POAG. As well as uncovering new biology, genetic information can be combined into a polygenic risk score (PRS), which aggregates an individual's disease risk over many genetic variants. In this nonsystematic review, performed from June 21, 2019, to October 1, 2020, we address a series of questions to explain the challenges and opportunities in translating genetic discoveries in POAG. We summarize what is known about POAG genetics and how its endophenotypes, such as intraocular pressure or cup-disc ratio, can help with prediction. We discuss the sample sizes available and how increases in the future may have an effect on the utility of prediction approaches. We explore particular scenarios, such as the use of PRS in risk stratification, and applications for individuals who are particularly high risk for POAG as a result of them carrying both a high penetrance mutation and an unfavorable PRS. Finally, we discuss the issue of equity in applying these tests and the prospects for prediction for people from various ancestry groups. The cost-effectiveness evaluation of glaucoma PRS in direct-to-consumer genetic testing and across different ancestry groups is warranted in future research.

Conclusions and Relevance

Advances in glaucoma genetics have opened the door for risk stratification based on genetic risk predictions. The PRS approach has shown good promise in predicting who will be at highest risk of POAG, which could improve outcomes if these predictions can be acted on to result in improved clinical outcomes.

Risk factors for open-angle glaucoma and recommendations for glaucoma screening

Open-angle glaucomas are a group of chronic progressive optic nerve neuropathies with a gonioscopic open anterior chamber angle. They are one of the main causes of visual impairment and blindness in industrialized countries. The aim of this article is to discuss and evaluate the epidemiology and risk factors for the development of open-angle glaucoma and to present the screening procedure for open-angle glaucoma according to the recently published S2e guidelines of the Association of the Scientific Medical Societies in Germany (AWMF).

[The role of citicoline in glaucoma]

Hintergrund

In den letzten Jahren wurde in vielen experimentellen und klinischen Studien gezeigt, dass bei der Glaukomerkrankung die neuronale Degeneration nicht nur auf der Höhe von Netzhaut und Sehnerv, sondern im Verlauf der gesamten Sehbahn und des Gehirns erfolgt.

Fragestellung

Dargestellt werden die neuroprotektive Wirkung und ihre Mechanismen von Citicolin bei der Glaukomerkrankung.

Material und Methode

Vor dem Hintergrund der Neuroanatomie, des Neuroimaging und der Pathogenese der Glaukomerkrankung wird die Relevanz erläutert. Die Daten der experimentellen und klinischen Studien werden dargelegt und ein Fazit für die klinische Anwendung gezogen.

Ergebnisse

Citicolin wirkt neuroprotektiv über glaukomrelevante Mechanismen. Die neuroprotektive Wirkung von Citicolin bei Offenwinkelglaukomen ist funktionell und morphologisch nachweisbar. Sie ist unabhängig vom Glaukomschaden und Augeninnendruck und tritt i. d. R. erst nach einem Jahr auf. Die Effekte von oralem Citicolin treten bei einer Tagesdosis von 500–1000 mg auf. Die Einnahme von Citicolin kann dauerhaft oder in Zyklen erfolgen. In den Studien traten bei der Einnahme von Citicolin keine Nebenwirkungen auf. Citicolin kann kognitive Leistungen und somit Therapieadhärenz sowie die Lebensqualität bei Glaukompatienten verbessern

Schlussfolgerung

Diese relativ alte nootrope Substanz, welche jetzt als Nahrungsergänzungsmittel vertrieben wird, scheint eine wertvolle Ergänzung zur konventionellen Therapie der Glaukomerkrankung und eine rationale Option zur Neuroprotektion und Prophylaxe zu sein.

Selective laser trabeculoplasty (SLT) performed by optometrists for patients with glaucoma and ocular hypertension: a scoping review

Selective laser trabeculoplasty (SLT) has been established as an effective treatment to lower intraocular pressure in people with glaucoma and ocular hypertension. The procedure is typically within the remit of ophthalmologists; however, there is potential to upskill optometrists and other healthcare professionals (HCPs) to deliver the treatment. We conducted a scoping review to identify the current global landscape of HCP-delivered SLT and describe training features, clinical effectiveness and safety. Relevant articles were identified through online database searches and grey literature sources. Four articles were selected for full inclusion. This review identified training programmes for optometrist-delivered SLT in the UK and the USA. The findings indicate that more research is needed to clarify training requirements and clinical effectiveness.

Trabecular meshwork's collagen network formation is inhibited by non-pigmented ciliary epithelium-derived extracellular vesicles

The present research aims to determine whether the application of non‐pigmented ciliary epithelium cells derived extracellular vesicles to human trabecular meshwork cells affects the formation and secretion of collagen type I to the extracellular matrix formation. Following the extraction of non‐pigmented ciliary epithelium derived extracellular vesicles by a precipitation method, their size and concentration were determined using tunable resistive pulse sensing technology. Extracellular vesicles were incubated with trabecular meshwork cells for 3 days. Morphological changes of collagen type I in the extracellular matrix of trabecular meshwork cells were visualized using confocal microscopy and scanning electron microscopy. A Sirius Red assay was used to determine the total amount of collagen. Finally, collagen type I expression levels in the extracellular matrix of trabecular meshwork cells were quantified by cell western analysis. We found that non‐pigmented ciliary epithelium extracellular vesicles were very effective at preventing collagen fibres formation by the trabecular meshwork cells, and their secretion to the extracellular matrix was significantly reduced (P < .001). Morphological changes in the extracellular matrix of trabecular meshwork cells were observed. Our study indicates that non‐pigmented ciliary epithelium extracellular vesicles can be used to control collagen type I fibrillogenesis in trabecular meshwork cells. These fibrils net‐like structure is responsible for remodelling the extracellular matrix. Moreover, we suggest that targeting collagen type I fibril assembly may be a viable treatment for primary open‐angle glaucoma abnormal matrix deposition of the extracellular matrix.