Risk factors for primary open angle glaucoma progression: what we know and what we need to know:

Predicting Glaucoma Progression to Surgery with Artificial Intelligence Survival Models

Purpose

Prior artificial intelligence (AI) models for predicting glaucoma progression have used traditional classifiers that do not consider the longitudinal nature of patients' follow-up. In this study, we developed survival-based AI models for predicting glaucoma patients' progression to surgery, comparing performance of regression-, tree-, and deep learning-based approaches.

Design

Retrospective observational study.

Subjects

Patients with glaucoma seen at a single academic center from 2008 to 2020 identified from electronic health records (EHRs).

Methods

From the EHRs, we identified 361 baseline features, including demographics, eye examinations, diagnoses, and medications. We trained AI survival models to predict patients' progression to glaucoma surgery using the following: (1) a penalized Cox proportional hazards (CPH) model with principal component analysis (PCA); (2) random survival forests (RSFs); (3) gradient-boosting survival (GBS); and (4) a deep learning model (DeepSurv). The concordance index (C-index) and mean cumulative/dynamic area under the curve (mean AUC) were used to evaluate model performance on a held-out test set. Explainability was investigated using Shapley values for feature importance and visualization of model-predicted cumulative hazard curves for patients with different treatment trajectories.

Main Outcome Measures

Progression to glaucoma surgery.

Results

Of the 4512 patients with glaucoma, 748 underwent glaucoma surgery, with a median follow-up of 1038 days. The DeepSurv model performed best overall (C-index, 0.775; mean AUC, 0.802) among the models studied in this article (CPH with PCA: C-index, 0.745; mean AUC, 0.780; RSF: C-index, 0.766; mean AUC, 0.804; GBS: C-index, 0.764; mean AUC, 0.791). Predicted cumulative hazard curves demonstrate how models could distinguish between patient who underwent early surgery and patients who underwent surgery after > 3000 days of follow-up or no surgery.

Conclusions

Artificial intelligence survival models can predict progression to glaucoma surgery using structured data from EHRs. Tree-based and deep learning-based models performed better at predicting glaucoma progression to surgery than the CPH regression model, potentially because of their better suitability for high-dimensional data sets. Future work predicting ophthalmic outcomes should consider using tree-based and deep learning-based survival AI models. Additional research is needed to develop and evaluate more sophisticated deep learning survival models that can incorporate clinical notes or imaging.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Estimated intracranial pressure in glaucoma patients and its correlation with disease severity

PURPOSE

To compare the intracranial pressure (ICP) and the translaminar pressure difference (TLPD) between primary open-angle glaucoma (POAG) patients and non-glaucoma subjects and to assess the correlation between the ICP (and TLPD) and glaucoma severity.

METHODS

This was a cross-sectional study. Patients with POAG and age-matched controls were included. ICP was calculated using proxy algorithm to attain indirect surrogate parameter values. Differences were compared between groups. The correlation between ICP (and TLPD) and both structural and functional variables was evaluated using linear and non-linear regression analysis and estimated with Pearson's correlation coefficient.

RESULTS

Fifty patients with POAG and 25 normal controls were included. The mean estimated ICP was lower in POAG (10.9 ± 3.2 mmHg) as compared to controls (15.0 ± 3.7 mmHg, p < 0.001). The TLPD was higher in POAG (2.6 ± 4.1 mmHg) when compared to non-glaucoma (-0.3 ± 3.6 mmHg, p = 0.002). ICP displayed a negative correlation with cup-to-disk ratio (r = -0.566; 95% CI, -0.699 to -0.369, p'0.000) and a positive correlation with retinal nerve fiber layer thickness (r = 0.441; 95% CI, 0.230 to 0.612; p'0.000). There was a positive correlation between ICP and mean deviation (r = 0.280; 95% CI, 0.05 to 0.482, p = 0.017).

CONCLUSION

Glaucoma patients presented lower ICP values; lower ICP values were associated with more advanced disease. These observations strengthen the role of ICP as a potential player on the glaucoma pathogeny.

Biochemical-molecular-genetic biomarkers in the tear film, aqueous humor, and blood of primary open-angle glaucoma patients

Introduction

Glaucoma is a chronic neurodegenerative disease, which is the leading cause of irreversible blindness worldwide. As a response to high intraocular pressure, the clinical and molecular glaucoma biomarkers indicate the biological state of the visual system. Classical and uncovering novel biomarkers of glaucoma development and progression, follow-up, and monitoring the response to treatment are key objectives to improve vision outcomes. While the glaucoma imaging field has successfully validated biomarkers of disease progression, there is still a considerable need for developing new biomarkers of early glaucoma, that is, at the preclinical and initial glaucoma stages. Outstanding clinical trials and animal-model study designs, innovative technology, and analytical approaches in bioinformatics are essential tools to successfully uncover novel glaucoma biomarkers with a high potential for translation into clinical practice.

Methods

To better understand the clinical and biochemical-molecular-genetic glaucoma pathogenesis, we conducted an analytical, observational, and case-comparative/control study in 358 primary open-angle glaucoma (POAG) patients and 226 comparative-control individuals (CG) to collect tears, aqueous humor, and blood samples to be processed for identifying POAG biomarkers by exploring several biological pathways, such as inflammation, neurotransmitter/neurotrophin alteration, oxidative stress, gene expression, miRNAs fingerprint and its biological targets, and vascular endothelial dysfunction, Statistics were done by using the IBM SPSS 25.0 program. Differences were considered statistically significant when p ≤ 0.05.

Results

Mean age of the POAG patients was 70.03 ± 9.23 years, and 70.62 ± 7.89 years in the CG. Malondialdehyde (MDA), nitric oxide (NO), interleuquin (IL)-6, endothelin-1 (ET-1), and 5 hydroxyindolacetic acid (5-HIAA), displayed significantly higher levels in the POAG patients vs. the CG (p < 0.001). Total antioxidant capacity (TAC), brain derived neurotrophic factor (BDNF), 5-hydroxy tryptamine (5-HT), solute carrier family 23-nucleobase transporters-member 2 (SLC23A2) gene, and the glutathione peroxidase 4 (GPX4) gene, showed significantly lower levelsin the POAG patients than in the CG (p < 0.001). The miRNAs that differentially expressed in tear samples of the POAG patients respect to the CG were the hsa miR-26b-5p (involved in cell proliferation and apoptosis), hsa miR-152-3p (regulator of cell proliferation, and extracellular matrix expression), hsa miR-30e-5p (regulator of autophagy and apoptosis), and hsa miR-151a-3p (regulator of myoblast proliferation).

Discussion

We are incredibly enthusiastic gathering as much information as possible on POAG biomarkers to learn how the above information can be used to better steer the diagnosis and therapy of glaucoma to prevent blindness in the predictable future. In fact, we may suggest that the design and development of blended biomarkers is a more appropriate solution in ophthalmological practice for early diagnosis and to predict therapeutic response in the POAG patients.

Comparison of posterior vitreous detachment-related and glaucomatous optic disc hemorrhage

This study compared the characteristics of posterior vitreous detachment (PVD)-related and glaucomatous optic disc hemorrhage (DH). Fundus photographs of eyes with PVD-related DH (PVD group) and glaucomatous DH (glaucoma group) were reviewed. The shape, type, layer, location (clock-hour sector), and DH/disc area (DH/DA) ratio of DH were investigated. In the PVD group, DH presented as a flame (60.9%), splinter (34.8%), and dot or blot (4.3%) shape. However, most of the glaucomatous DH revealed a splinter shape (92.3%), followed by a flame shape (7.7%, p < 0.001). In the PVD group, the most common type of DH was cup margin type (52.2%), whereas, in the glaucoma group it was disc rim type (53.8%, p = 0.003). Both PVD-related and glaucomatous DH were most commonly observed in the 7 o'clock sector. In the PVD group, DH was also found in the 2 and 5 o'clock sectors (p = 0.010). Mean DH/DA ratio in PVD group (0.15 ± 0.19) was greater than in glaucoma group (0.04 ± 0.04, p < 0.001). PVD-related DH showed a higher frequency of flame shape, cup margin type, nasal location, and greater area compared to the glaucomatous DH.

Deep Learning Approaches for Predicting Glaucoma Progression Using Electronic Health Records and Natural Language Processing

Purpose

Advances in artificial intelligence have produced a few predictive models in glaucoma, including a logistic regression model predicting glaucoma progression to surgery. However, uncertainty exists regarding how to integrate the wealth of information in free-text clinical notes. The purpose of this study was to predict glaucoma progression requiring surgery using deep learning (DL) approaches on data from electronic health records (EHRs), including features from structured clinical data and from natural language processing of clinical free-text notes.

Design

Development of DL predictive model in an observational cohort.

Participants

Adult patients with glaucoma at a single center treated from 2008 through 2020.

Methods

Ophthalmology clinical notes of patients with glaucoma were identified from EHRs. Available structured data included patient demographic information, diagnosis codes, prior surgeries, and clinical information including intraocular pressure, visual acuity, and central corneal thickness. In addition, words from patients’ first 120 days of notes were mapped to ophthalmology domain-specific neural word embeddings trained on PubMed ophthalmology abstracts. Word embeddings and structured clinical data were used as inputs to DL models to predict subsequent glaucoma surgery.

Main Outcome Measures

Evaluation metrics included area under the receiver operating characteristic curve (AUC) and F1 score, the harmonic mean of positive predictive value, and sensitivity on a held-out test set.

Results

Seven hundred forty-eight of 4512 patients with glaucoma underwent surgery. The model that incorporated both structured clinical features as well as input features from clinical notes achieved an AUC of 73% and F1 of 40%, compared with only structured clinical features, (AUC, 66%; F1, 34%) and only clinical free-text features (AUC, 70%; F1, 42%). All models outperformed predictions from a glaucoma specialist’s review of clinical notes (F1, 29.5%).

Conclusions

We can successfully predict which patients with glaucoma will need surgery using DL models on EHRs unstructured text. Models incorporating free-text data outperformed those using only structured inputs. Future predictive models using EHRs should make use of information from within clinical free-text notes to improve predictive performance. Additional research is needed to investigate optimal methods of incorporating imaging data into future predictive models as well.

Efficacy of Nimodipine Combined with Latanoprost in Treating Open-Angle Glaucoma and Its Influence on Ocular Hemodynamics and Visual Field Defects

Background

Open-angle glaucoma is a common ophthalmic disease, which has a great impact on the vision of middle-aged and elderly people. Medication plays an important role in the treatment of glaucoma, so finding effective drug treatment is of great significance to improve the quality of life of glaucoma patients.

Objective

To explore the curative effect of nimodipine combined with latanoprost in the treatment of open-angle glaucoma and its effect on ocular hemodynamics and visual field defects.

Methods

This study retrospectively analyzed the clinical data of 87 patients with open-angle glaucoma who came to the Shanxi Province Fenyang Hospital and The First Affiliated Hospital of Shanxi Datong University for treatment from January 2019 to January 2021. According to different treatment plans, the patients were divided into two groups: an observation group (n = 46) treated with nimodipine combined with latanoprost, and a control group (n = 41) treated by latanoprost monotherapy. Treatment efficacy, hemodynamics, visual field defects, 24-hour peak intraocular pressure, binocular optic disc parameters, adverse reactions and quality of life were recorded and compared between two groups of patients.

Results

The overall therapeutic effect of the observation group was significantly better than that in the control group. After treatment, ocular hemodynamics, visual field defects, 24-hour peak intraocular pressure, binocular optic disc parameters and life quality of both groups were obviously improved compared to those before treatment, with more significant improvements in the observation group. In addition, there was no significant difference in the incidence of adverse reactions between the two groups.

Conclusion

Nimodipine combined with latanoprost eye drops is effective in the treatment of primary open-angle glaucoma, which could effectively improve the ocular hemodynamics and visual field defects of patients with fewer adverse reactions and higher safety. Therefore, it can be further promoted and used in clinical practice.

ReGAE 12: preventing glaucoma blindness in the Caribbean through implementation of the Moorfields Safer Surgery System and skills transfer from the UK to Trinidad and Tobago

Objective

The objective of the study was to present evidence of successful skills transfer of the Moorfields Safer Surgery System (MSSS) from the UK to Trinidad and Tobago and the safety and efficacy of this technique.

Methods

Hospital-based retrospective, consecutive, non-comparative case series study of 33 eyes (24 African-Caribbean patients; 16 male patients) with primary open-angle glaucoma undergoing trabeculectomy + mitomycin C (MSSS) by a single surgeon with UK Glaucoma Fellowship training. The clinical outcome measures included intraocular pressure (IOP), bleb morphology, postsurgical interventions, postoperative complications, and best-corrected visual acuity (BCVA) at the final follow-up.

Results

All patients were self-identified as African-Caribbean. The median age was 56 years (range 34-79 years). The mean preoperative IOP on maximum tolerated medical treatment was 22.4 mmHg (SD=5.9 mmHg). With or without medication, IOP was ≤21 mmHg in 92.6% at 1 year and 87.5% at 5 years. At 1 year, IOP was ≤18 mmHg in 78%, ≤15 mmHg in 73% and ≤14 mmHg in 52%. Removal of scleral flap releasable suture(s) was performed in 84%, 5-fluorouracil injection(s) in 88% and bleb needling revision in 38%. The most common complication was early transient bleb leak (52%). No patient developed endophthalmitis, hypotony maculopathy, suprachoroidal hemorrhage, or malignant glaucoma. At the final follow-up, 91% had excellent or satisfactory bleb morphology, and 73% had equal or better BCVA.

Conclusion

Skills transfer between different geographical and economic regions contributes to the prevention of avoidable blindness through disease control - one of the core strategies of the World Health Organization's Vision 2020 initiative. In the Caribbean (Trinidad and Tobago), the MSSS was utilized by a surgeon with Glaucoma Fellowship training and achieved outcomes similar to best-published data. This success can be reproduced in other geographic locations.

Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine

The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now needed to confirm the causal role of stress in different low vision diseases to evaluate the efficacy of different anti-stress therapies for preventing progression and improving vision recovery and restoration in randomized trials as a foundation of psychosomatic ophthalmology.

Predictive Value of the Water Drinking Test and the Risk of Glaucomatous Visual Field Progression

PURPOSE

The purpose of this is to test the hypothesis the intraocular pressure (IOP) peaks during a stress test [the water drinking test (WDT)] can estimate the risk of future visual field progression in treated primary open-angle glaucoma (POAG) patients.

PATIENTS AND METHODS

Design: Prospective, longitudinal study.

SETTING

Clinical practice.

STUDY POPULATION

Treated POAG patients whose IOP was ≤18 mm Hg and who had no IOP-lowering interventions between the date of the WDT and the last eligible visual field.

INTERVENTION

At baseline examination, patients underwent the WDT and were then followed at regular intervals with office-based IOP measurements and visual field testing.

MAIN OUTCOME MEASURE

Cox-proportional hazards survival analysis testing the predictive value of IOP peaks during the WDT versus IOP measurements during office hours on visual field progression.

RESULTS

A total of 144 eyes of 96 patients with baseline visual field damage ranging from mild to severe followed for a mean of 28 months were analyzed. In the multivariable analysis adjusting for potential confounders, higher IOP peaks during the WDT were predictive of future visual field progression (hazard ratio=1.11; 95% confidence interval, 1.02 to 1.21; P=0.013). The average and peak IOP during office hours over the same follow-up period were not significantly associated with progression (P=0.651 and 0.569, respectively).

CONCLUSIONS

IOP peaks detected with the WDT were predictive of future visual field progression in a treated POAG population. This stress test could be a useful tool for risk assessment in daily practice.

Risk Factors for Primary Open Angle Glaucoma (POAG) Progression: A Study Ruled in Torino

Purpose:

Aim of this retrospective, observational study is to describe features of a population sample, affected by primary open angle glaucoma (POAG) in order to evaluate damage progression on the basis of the emerged individual risk factors.

Methods:

We included 190 caucasian patients (377 eyes), evaluating relationship between individual risk factors (explicative variables) and MD (Mean Deviation) of standard automated perimetry. We also considered the dependent variable NFI (Neural Fiber Index) of GDx scanning laser polarimetry. Progression has been evaluated through a statistic General Linear Model on four follow up steps (mean follow up 79 months).

Results:

Factors reaching statistical significance, determining a worsening of the MD variable, are: age (P<0.0001), intraocular pressure (IOP) at follow up (P < 0.0001), female gender (P<0.0001), hypertension (P< 0.0001) and familiarity (P = 0.0006).

Factors reaching statistical significance, determining a worsening of the NFI variable, are only IOP at follow up (P = 0.0159) and depression (P = 0.0104).

Conclusion:

Results of this study confirm and enforce data coming from most recent studies: IOP remains the main risk factor for glaucoma assess and progression; age and familiarity are great risk factors as underlined in the last decades; female sex can be an important risk factors as emerged only in the last years; arterial hypertension should always be evaluated in timing of our clinic follow up.

The applicability of correction factor for corneal thickness on non-contact tonometer measured intraocular pressure in LASIK treated eyes

Purpose

To determine the applicability of central corneal thickness (CCT) based correction factor for non-contact tonometer (NCT) measured intraocular pressure (IOP) readings.

Method

A prospective, non-randomized study involved 346 eyes of 173 consecutive patients with age ⩾21 years undergoing laser-assisted in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism. The CCT and IOP were measured before and after the LASIK procedure. The IOP pre and post-LASIK was compared after applying the correction factor for CCT. Patients not completing the 3 month postoperative follow-up were excluded.

Results

The median spherical equivalent before undergoing LASIK was −4.25D (inter-quartile range, −3.25D). The mean preoperative CCT was 536.82 ± 33.71 μm which reduced to 477.55 ± 39.3 μm (p < 0.01) post-LASIK. The mean IOP reduced from a preoperative value of 14.6 ± 2.32 mmHg to 10.64 ± 2.45 mmHg postoperatively (p < 0.01). On applying correction for the corneal thickness, the pre and postoperative IOP was 15.14 ± 2.8 mmHg and 15.37 ± 2.65 mmHg (p = 0.06) respectively with a strong positive correlation (r = 0.7, p < 0.01). Three hundred eyes (86.7%) had an absolute difference in IOP of less than 3.0 mmHg post-CCT correction which is within the retest variability of NCT. Only 46 eyes (13.3%) had an absolute difference of more than 3.0 mmHg.

Conclusion

The modified Ehler’s correction algorithm used in this study can be effectively applied in the normal IOP range in a majority of patients.

Aniridic Glaucoma: Long-term Visual Outcomes and Phenotypic Associations

PURPOSE

The aim of this study was to evaluate long-term visual outcomes in patients with aniridic glaucoma.

DESIGN

Retrospective noncomparative observational case series.

MATERIALS AND METHODS

A review of medical records of 128 eyes of 64 consecutive patients with aniridic glaucoma, diagnosed after the age of 5 years was analyzed. The parameters studied included age at presentation, family history, baseline intraocular pressure (IOP), type and the number of surgical interventions, and associated comorbidities.

PRIMARY OUTCOME MEASURE

Best corrected visual acuity (BCVA) in the better eye.

RESULTS

Mean age at presentation was 15.86±10.11 years (range, 5 to 47 y). The average follow-up was 7.69±4.98 years (range, 1 to 17 y). At the final follow up only 18 patients had BCVA better than 6\60 and only 5 patients had BCVA of >6/18. Seventeen of the 64 (26.5%) patients developed phthisis in 1 eye. The final visual outcomes were not associated with age at presentation (P=0.64) or sex (P=0.76); however, those with a higher baseline IOP (P=0.017), those with familial aniridia (P=0.037), and those who underwent more number of surgical interventions had poorer visual outcomes (P=0.004). Kaplan-Meier analysis demonstrated the probability of bilateral blindness to be 69.8% and 97.6% at 5 and 10 years, respectively.

CONCLUSIONS

Long-term visual outcomes after therapy among aniridic glaucoma patients remain poor. Higher baseline IOP, the presence of familial aniridia, and a history of greater number of surgical interventions are associated with poorer long-term visual outcomes.

Repeatability and reproducibility of applanation resonance tonometry: a cross-sectional study

Background

To assess repeatability (intra-observer variability) and reproducibility (inter-operator variability) of intraocular pressure (IOP) measurements with servo-controlled Bioresonator Applanation Resonance Tonometry (ART) and to evaluate possible influential factors.

Methods

The study included 178 patients (115 glaucoma and 63 controls; one eye per subject). IOP was measured once with a Goldmann applanation tonometer (GAT) and twice by ART (ART1, ART2), in randomized sequence, by a single operator to assess intra-operator variability. Each ART measurement consisted on 3 readings. To assess inter-operator variability 2 evaluators performed 2 measurements each (in random order) on the same patient. Repeatability and reproducibility were assessed by the coefficient of variation (CoV) and intraclass correlation coefficient (ICC).

Results

In the entire cohort, ART1 was 0.4 ± 2.2 mmHg (−7.0 to 5.7 mmHg) higher than ART2 (p = 0.03) regardless of test order. Intra-operator CoV was 7.0% ± 6.3%, and ICC was 0.80-0.92. Inter-operator CoV ranged between 5.7% ± 6.1% and 8.2% ± 7.2%, and ICC between 0.86 and 0.97. ART1 and 2 were respectively 1.7 ± 3.1 and 1.3 ± 3.1 mmHg higher than GAT (p < 0.01). Test-retest difference with ART fell within ±1 mmHg in 41% of cases, within ±2 mmHg in 70%, within ±3 mmHg in 85%. 15% had a test-retest difference higher than ± 3 mmHg; Bland-Altman 95% intervals of confidence were −3.9 and +4.6 mmHg. Results were unaffected by age, diagnosis, central corneal thickness, keratometry, operator, randomization sequence.

Conclusions

In most cases ART repeatability and reproducibility were high, with no differences due to patients’ characteristics. ART measurements overestimated GAT by a mean of 1.3-1.7 mmHg.

Mutated myocilin and heterozygous Sod2 deficiency act synergistically in a mouse model of open-angle glaucoma

Glaucoma is a multifactorial optic neuropathy characterized by retinal ganglion cell (RGC) death and axonal degeneration leading to irreversible blindness. Mutations in the myocilin (MYOC) gene are the most common genetic factors of primary open-angle glaucoma. To develop a genetic mouse model induced by the synergistic interaction of mutated myocilin and another significant risk factor, oxidative stress, we produced double-mutant mice (Tg-MYOC(Y437H/+)/Sod2(+/-)) bearing human MYOC with a Y437H point mutation and a heterozygous deletion of the gene for the primary antioxidant enzyme, superoxide dismutase 2 (SOD2). Sod2 is broadly expressed in most tissues including the trabecular meshwork (TM) and heterozygous Sod2 knockout mice exhibit the reduced SOD2 activity and oxidative stress in all studied tissues. Accumulation of Y437H myocilin in the TM induced endoplasmic reticulum stress and led to a 45% loss of smooth muscle alpha-actin positive cells in the eye drainage structure of 10- to 12-month-old Tg-MYOC(Y437H/+)/Sod2(+/-) mice as compared with wild-type littermates. Tg-MYOC(Y437H/+)/Sod2(+/-) mice had higher intraocular pressure, lost about 37% of RGCs in the peripheral retina, and exhibited axonal degeneration in the retina and optic nerve as compared with their wild-type littermates. Single-mutant littermates containing MYOC(Y437H/+) or Sod2(+/-) exhibited no significant pathological changes until 12 months of age. Additionally, we observed elevated expression of endothelial leukocyte adhesion molecule-1, a human glaucoma marker, in the TM of Tg-MYOC(Y437H/+)/Sod2(+/-) mice. This is the first reported animal glaucoma model that combines expression of a glaucoma-causing mutant gene and an additional mutation mimicking a deleterious environment factor that acts synergistically.

Therapeutic endorsement enhances compliance with national glaucoma guidelines in Australian and New Zealand optometrists

PURPOSE

Previous studies confirmed that optometrists have access to and confidence in applying clinical tests recommended for glaucoma assessment. Less is known about factors best predicting compliance with national clinical guidelines and thus by inference, the provision of suitable care by primary care ophthalmic practitioners. We utilised the unique two-tiered profession (therapeutic and non-therapeutic scope of practice) in Australia and New Zealand to assess the prospective adherence to glaucoma guidelines dependent on the clinician's background.

METHODS

Australian and New Zealand optometrists were surveyed on ophthalmic techniques for glaucoma assessment, criteria for the evaluation of the optic nerve head, glaucoma risk categories and review times while also recording background, training, and experience. Parameters identifying progression/conversion and patients' risk levels were analysed comparatively to ophthalmologists' opinions. Linear regression analysis identified variables significantly improving the likelihood of concordance with guidelines.

RESULTS

Reported application of techniques complied well with glaucoma guidelines although gonioscopy and pachymetry, pupil dilation for optic nerve head examination, and acquisition of permanent records were less frequently employed. The main predictors for entry-level diagnostic standards were therapeutic endorsement together with the associated knowledge of relevant guidance and procedural confidence. Other findings suggested a potential underestimation in the value of optic disc size and intraocular pressure for the prediction of glaucoma risk, while optometrists more frequently relied on the outcomes of non-standardised automated perimetry and auxiliary imaging.

CONCLUSIONS

Optometrists in Australia and New Zealand may not always exercise optimal clinical acumen regarding techniques/criteria for glaucoma diagnosis. Therapeutic endorsement was gradually adopted in different jurisdictions in various forms since 1999 and is mandatory for registration since late 2014. The result of the two-tiered optometric cohorts suggest that inclusion of therapeutic training as part of the core training is likely a key factor to enhanced compliance with glaucoma guidelines. Improved adherence to the current clinical standards should positively impact on the facilitation of appropriate glaucoma diagnosis and management. Obligatory knowledge and possibly accreditation of available guidelines might ensure a uniform standard in glaucoma testing protocols in concordance with compulsory entry-level skills.

Clinical model assisting with the collaborative care of glaucoma patients and suspects

BACKGROUND

Optimizing patient management will reduce unnecessary vision loss in glaucoma through early detection. One method is the introduction of collaborative care schemes between optometrists and ophthalmologists.

DESIGN

We conducted a retrospective study to evaluate the impact of the Centre for Eye Health (CFEH) on glaucoma patient outcomes and management in primary optometric care.

PARTICIPANTS

Patients referred to CFEH by optometrists for a glaucoma assessment were eligible for this study if written consent was provided (500 participants were randomly chosen).

METHODS

Clinical data were classified according to disease risk and implemented patient care and analysed against the original diagnosis and patient parameters, followed by statistical analysis.

MAIN OUTCOME MEASURES

Two main parameters were evaluated; suitable referral of patients for glaucoma condition assessment and appropriate implementation of follow-up care.

RESULTS

The majority of patients referred for glaucoma assessment (86.2%) were classified as glaucoma suspects or likely to have glaucoma, indicating suitable referral of patients for a CFEH evaluation. Further, the involvement of CFEH resulted in a false positive rate of 7.8% for those patients who proceeded to ophthalmological care. However, long-term optometric patient care was not maintained for up to a third of primarily lower risk patients.

CONCLUSIONS

The investigated collaborative eye health-care model led to a substantial improvement in appropriate referrals of glaucoma patients to ophthalmologists and could be suitable for optimizing patient care and utilization of resources. Improvement in follow-up of patients by optometrists is required to minimize inappropriately discontinued patient care.

Diabetes mellitus as a risk factor for open-angle glaucoma: a systematic review and meta-analysis

Objective

To determine the association between diabetes mellitus (DM) and primary open-angle glaucoma (POAG).

Methods

This is a systematic review and meta-analysis of case-control and cohort studies. The literature search included two databases (PubMed and Embase) and the reference lists of the retrieved studies. Separate meta-analyses for case-control studies and cohort studies were conducted using random-effects models, with results reported as adjusted odds ratios (ORs) and relative risks (RRs), respectively.

Results

Thirteen studies—seven case-control studies and six population-based cohort studies—were included in this meta-analysis. The pooled RR of the association between DM and POAG based on the risk estimates of the six cohort studies was 1.40 (95% CI, 1.25–1.57). The pooled OR of the association between DM and POAG based on the risk estimates of the seven case-control studies was 1.49 (95% CI, 1.17–1.88). There was considerable heterogeneity among the case-control studies that reported an association between DM mellitus and POAG (P<0.001) and no significant heterogeneity among the cohort studies (P = 0.377). After omitting the case-control study that contributed significantly to the heterogeneity, the pooled OR for the association between DM and POAG was 1.35 (95% CI, 1.06–1.74).

Conclusions

Individuals with DM have an increased risk of developing POAG.

A proposed methodology for the assessment of glaucoma awareness in Greece: introduction of the EIT-8G scale

PURPOSE

To develop a reliable and practical questionnaire for glaucoma awareness and evaluate the impact of potential determinants.

METHODS

Patients with primary open-angle, pigmentary, and exfoliation glaucoma, as well as healthy controls, were recruited. The instrument included questions about demographic characteristics, as well as 8 questions assessing the participant's familiarity with glaucoma. Rasch analysis was used for the validation of the questionnaire. The effect of demographics as potential determinants of awareness was examined with a multivariate logistic regression analysis. Bonferroni-corrected statistical significance was tested with the Mann-Whitney U test or one-way analysis of variance. Association between demographics and questionnaire scores was examined with Spearman correlation.

RESULTS

As indicated by power analysis, responses from 175 patients (mean age 65.5 years) and 314 controls (mean age 43.3 years) were analyzed. Rasch analysis indicated no multidimensionality and good item-person targeting. Mean ± SD awareness scores for the glaucoma and control groups were 4.43 ± 2.10 and 4.20 ± 2.11, respectively (p=0.207). Sex and residence were not predictors of disease awareness, whereas educational level was only a determinant in the control group (p<0.001). Income was a predictor only for patients (r=0.357, p<0.001), whereas family history was predictive for both groups (p<0.001). Logistic regression analysis revealed that only family history was associated with increased awareness (Chi(2)=4.61, p=0.03, odds ratio 1.98).

CONCLUSIONS

This study introduces a practical and valid instrument for the assessment of glaucoma awareness.

Intraocular pressure assessment after laser in situ keratomileusis: a review

This paper aims to review the current methods available for the measurement of intraocular pressure after myopic laser in situ keratomileusis for the correction of myopia. Searches were performed for studies that assessed or compared various methods of intraocular pressure assessment. There were 20 eligible studies that explored the use of pneumotonometry, pressure phosphene tonometry, rebound tonometry, dynamic contour tonometry, statistical modeling, mathematical formulae, ocular response analyzer and even measuring intraocular pressure on the nasal cornea. Our review shows that an ideal method would be one that is independent of corneal factors. Dynamic contour tonometry and pressure phosphene tonometry held promise in research settings. More studies need to be done to validate the new methods of intraocular pressure assessment, especially in glaucoma patients. It is important to empower laser in situ keratomileusis patients with knowledge of these difficulties and potential implications for the future.

Blindness and long-term progression of visual field defects in chinese patients with primary angle-closure glaucoma

PURPOSE

To investigate the long-term rates of blindness and visual field (VF) progression in treated primary angle-closure glaucoma (PACG) patients.

DESIGN

Retrospective observational case series.

METHODS

PACG patients with ≥10 years of follow-up were analyzed. All VFs (static automated perimetry, central 24-2 threshold test) performed were reviewed and reliable VFs (fixation losses <20%, false positives and false negatives <33%) were scored using the Advanced Glaucoma Intervention Study (AGIS) system. Progression of a VF defect was defined as a change of ≥4 from baseline on 2 consecutive VF tests.

RESULTS

From the 137 eyes of 87 patients with PACG with ≥10 years of follow-up identified, 6% and 30.1% were blind based on initial visual acuity (VA) and VF criteria respectively and 12.0% had an initial AGIS score of 20; these were excluded. Eighty-three eyes from 57 patients (all Chinese, mean age 59.9 ± 8.2 years, 67.5% female) were analyzed. The mean AGIS score was 5.14 ± 4.37 at baseline. VF deterioration was detected in 27 eyes (32.5%) of 21 patients, with 4.8% and 7.2% of eyes progressing to blindness based on VA and VF criteria respectively. On Cox regression, eyes with VF progression had higher mean overall IOP (P < .001), and higher prevalence of previous acute angle closure (AAC, P = .008).

CONCLUSIONS

Over 10 years, a third of PACG patients were found to have VF progression, with 7% progressing to blindness while on treatment. Eyes with higher mean overall IOP and a history of previous AAC were more likely to have VF progression.

Complement mediated apoptosis leads to the loss of retinal ganglion cells in animal model of glaucoma

This study investigated the role of complement in the protection of retinal ganglion cells (RGCs) in chronic ocular hypertension model of glaucoma. Intraocular pressure (IOP) was elevated in the right eye of Lewis rats by laser photocoagulation (two treatments, 7days apart) of episcleral and limbal veins. Left eye did not receive laser treatment and served as control. Animals were injected with cobra venom factor every fifth day starting day 7 after first laser, to deplete the complement system. Animals were sacrificed at 6-week post-laser. Levels of C3 split products and membrane attack complex (MAC) were elevated in the retina of eyes with increased IOP and complement depletion reduced the loss of Brn3a(+) RGCs accompanied by decreased expression of GFAP and reduced MAC deposition. In complement depleted rats with increased IOP, reduced TUNEL(+) cells in ganglion cell layer, and decreased levels of active caspase-8 and active caspase-9 was observed compared to PBS treated complement sufficient rats with increased IOP. Interestingly, complement depletion also resulted in reduction of calcium influx and levels of BAD in the retinal cells of the eyes with increased IOP. Together, our results provide evidence that complement mediated apoptosis plays a pivotal role in the loss of RGCs in chronic ocular hypertension model of glaucoma.

Ocular hypotensive activity of BOL-303259-X, a nitric oxide donating prostaglandin F2α agonist, in preclinical models

The aim of the study was to investigate the ocular hypotensive activity of a nitric oxide (NO)-donating latanoprost, BOL-303259-X, following topical administration. The effect of BOL-303259-X (also known as NCX 116 and PF-3187207) on intraocular pressure (IOP) was investigated in monkeys with laser-induced ocular hypertension, dogs with naturally-occurring glaucoma and rabbits with saline-induced ocular hypertension. Latanoprost was used as reference drug. NO, downstream effector cGMP, and latanoprost acid were determined in ocular tissues following BOL-303259-X administration as an index of prostaglandin and NO-mediated activities. In primates, a maximum decrease in IOP of 31% and 35% relative to baseline was achieved with BOL-303259-X at doses of 0.036% (9 μg) and 0.12% (36 μg), respectively. In comparison, latanoprost elicited a greater response than vehicle only at 0.1% (30 μg) with a peak effect of 26%. In glaucomatous dogs, IOP decreased from baseline by 44% and 10% following BOL-303259-X (0.036%) and vehicle, respectively. Latanoprost (0.030%) lowered IOP by 27% and vehicle by 9%. Intravitreal injection of hypertonic saline in rabbits increased IOP transiently. Latanoprost did not modulate this response, whereas BOL-303259-X (0.036%) significantly blunted the hypertensive phase. Following BOL-303259-X treatment, latanoprost acid was significantly elevated in rabbit and primate cornea, iris/ciliary body and aqueous humor as was cGMP in aqueous humor. BOL-303259-X lowered IOP more effectively than latanoprost presumably as a consequence of a contribution by NO in addition to its prostaglandin activity. The compound is now in clinical development for the treatment of glaucoma and ocular hypertension.

Relationship between severity of visual field loss at presentation and rate of visual field progression in glaucoma

PURPOSE

To evaluate the relationship between severity of visual field (VF) loss at presentation and rate of VF progression in glaucoma.

DESIGN

Clinic-based, retrospective study.

PARTICIPANTS

We included 512 eyes of 310 primary glaucoma patients.

METHODS

We analyzed the VFs of all subjects of primary glaucoma who had >5 VFs between 1989 and 2008. Based on the mean deviation (MD), we classified the VF loss as mild (MD > -6 dB), moderate (MD ≤ -6 to ≥ -12 dB) or severe (MD < -12 dB). Guided Progression Analysis software which gives the rate of progression (ROP) of Visual Field Index per year was used to assess the ROP.

MAIN OUTCOME MEASURES

Relationship between severity of VF loss at presentation and ROP.

RESULTS

The median duration of follow-up was 6.8 years. The ROP increased (worsened) by 0.02% per year for every dB worsening of MD (P = 0.02) and for every year of increasing age (P = 0.001). Association between MD and ROP showed a significant positive relationship in mild (β = 0.18; P = 0.001) and a significant negative relationship in severe (β = -0.16; P<0.001) VF loss category. Association between MD and ROP was not significant in the moderate VF loss category (β = -0.05; P = 0.61).

CONCLUSIONS

In early stages of glaucoma, the ROP worsened as the severity increased, but, in later stages of the disease, ROP became smaller as the severity increased. There is a need for better methods to detect progression in eyes with severe glaucomatous damage.

Relationship of intraocular pulse pressure and spontaneous venous pulsations

PURPOSE

To determine the influence of intraocular pulse pressure (IOPP) on the presence of spontaneous venous pulsations (SVP) in patients with normal intracranial pressure.

DESIGN

Clinic-based cross-sectional study.

METHODS

Forty-seven patients without signs and symptoms of elevated intracranial pressure were recruited from a general ophthalmology clinic. Patients with glaucoma or retinal vascular disease were excluded from the study. IOP was determined by applanation, and IOPP was measured with the Pascal Dynamic Contour Tonometer (Ziemer Group, Port, Switzerland). SVP were assessed by undilated (direct) and dilated indirect ophthalmoscopy. Other variables assessed included age, cup-to-disc ratio, and refractive error (spherical equivalent). The main outcome measure was the presence of SVPs with normal IOPP.

RESULTS

The incidence of SVPs declined with increasing age in a nonlinear manner. Dilated examinations yielded the greatest sensitivity for detecting SVPs, with 91.5% of subjects having SVPs. However, in subjects with IOPP of 1.2 mm Hg or more in at least one eye, the incidence of SVPs was 100%.

CONCLUSIONS

A significant correlation exists between the amplitude of IOPP and the presence of SVPs, with SVPs detected in one or both eyes of all patients with IOPP of 1.2 mm Hg or more. When IOPP is 1.2 mm Hg or more, absent SVPs may be more predictive of elevated intracranial pressure than previously recognized.