Disease severity in newly diagnosed glaucoma patients with visual field loss: trends from more than a decade of data

Glaucoma Severity Stage at First Visit at a University Eye Clinic in Congo

PRCIS

Initial presentation of glaucoma at a major eye clinic mostly features advanced disease with a high proportion of blindness. This is likely a microcosm of a nationwide issue requiring concerted strategies to detect glaucoma early.

PURPOSE

To characterize the severity stage of new glaucoma patients in Congolese attending a university eye clinic.

METHODS

New glaucoma patients (n=118) were labeled as early or late presenters based on visual field sensitivity in the worse eye.

RESULTS

Mean age was 58.9±15.7 years, 51.7% were males. Overall, the worse eye had advanced, whereas the better eye had moderate glaucoma, with an asymmetry of -7.4 dB ( P <0.001). Blindness was present in 30.5% of worse and 5.1% of better eyes. Seventy-two patients (61.0%) were late presenters. Visual acuity was lower ( P <0.001), intraocular pressure (IOP) higher ( P =0.02), cup-to-disc ratio larger ( P =0.011), and retinal nerve fiber layer thinner ( P =0.001) in late presenters' worse than better eye. The worse and better eyes of late presenters had advanced glaucoma, with a -9.6 dB interocular asymmetry ( P <0.001); 40.3% and 8.3% were blind, respectively. In early presenters, the worse and better eyes had moderate and early disease, respectively; the asymmetry was -3.2 dB ( P <0.001), and 15.2% were blind. Overall, 58.5% and 65.3% presented with advanced disease in the worse eye based on visual field and cup-to-disc ratio criteria of the Canadian Ophthalmological Society staging scale, respectively.

CONCLUSIONS

Most new glaucoma patients had bilateral advanced but asymmetric disease. These findings call for the establishment of community-based measures for early detection of glaucoma and a referral network system connecting community healthcare to tertiary eye clinics.

Evaluating Primary Treatment for People with Advanced Glaucoma: Five-Year Results of the Treatment of Advanced Glaucoma Study

PURPOSE

To determine whether primary trabeculectomy or medical treatment produces better outcomes in terms of quality of life (QoL), clinical effectiveness, and safety in patients with advanced glaucoma.

DESIGN

Multicenter randomized controlled trial.

PARTICIPANTS

Between June 3, 2014, and May 31, 2017, 453 adults with newly diagnosed advanced open-angle glaucoma in at least 1 eye (Hodapp classification) were recruited from 27 secondary care glaucoma departments in the United Kingdom. Two hundred twenty-seven were allocated to trabeculectomy, and 226 were allocated medical management.

METHODS

Participants were randomized on a 1:1 basis to have either mitomycin C-augmented trabeculectomy or escalating medical management with intraocular pressure (IOP)-reducing drops as the primary intervention and were followed up for 5 years.

MAIN OUTCOME MEASURES

The primary outcome was vision-specific QoL measured with the 25-item Visual Function Questionnaire (VFQ-25) at 5 years. Secondary outcomes were general health status, glaucoma-related QoL, clinical effectiveness (IOP, visual field, and visual acuity), and safety.

RESULTS

At 5 years, the mean ± standard deviation VFQ-25 scores in the trabeculectomy and medication arms were 83.3 ± 15.5 and 81.3 ± 17.5, respectively, and the mean difference was 1.01 (95% confidence interval [CI], -1.99 to 4.00; P = 0.51). The mean IOPs were 12.07 ± 5.18 mmHg and 14.76 ± 4.14 mmHg, respectively, and the mean difference was -2.56 (95% CI, -3.80 to -1.32; P < 0.001). Glaucoma severity measured with visual field mean deviation were -14.30 ± 7.14 dB and -16.74 ± 6.78 dB, respectively, with a mean difference of 1.87 (95% CI, 0.87-2.87 dB; P < 0.001). Safety events occurred in 115 (52.2%) of patients in the trabeculectomy arm and 124 (57.9%) of patients in the medication arm (relative risk, 0.92; 95% CI, 0.72-1.19; P = 0.54). Serious adverse events were rare.

CONCLUSIONS

At 5 years, the Treatment of Advanced Glaucoma Study demonstrated that primary trabeculectomy surgery is more effective in lowering IOP and preventing disease progression than primary medical treatment in patients with advanced disease and has a similar safety profile.

FINANCIAL DISCLOSURE(S)

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

Comparison of disease severity in glaucoma patients identified by screening in the 1990s and in routine clinical care in the 2010s in Sweden

BACKGROUND AND PURPOSE

In a previous study comparing the amount of visual field damage at presentation in patients having open-angle glaucoma (OAG) identified through screening and in patients diagnosed in routine clinical practice in the 1990s, the damage was considerably worse in the clinically diagnosed patients. In the present study we compare visual field damage at presentation in the same 402 screened patients with that seen in 281 newly detected previously untreated patients clinically diagnosed in the 2010s.

METHODS

The perimetric visual field index mean deviation (MD) was compared in the two groups of patients.

RESULTS

In the clinical patients diagnosed with bilateral visual field damage the median MD was -5.1 dB in the better eye and -13.0 dB in the worse eye. In the screened patients the median MD in the better eye was -6.5 dB and -11.5 dB in the worse eye. The differences between the clinical and screened patients were non-significant, p = 0.28 and p = 0.67 respectively. More clinical patients had severe visual field loss, defined as MD less than -20 dB, in the worse eye than in the screened patients, 18.5% versus 12.7% respectively, p = 0.037.

CONCLUSION

The visual field damage at presentation in clinically diagnosed OAG patients has improved in the past 20 years, but the proportion of patients with severe visual field loss in at least one eye, almost 20%, is still unacceptably high considering that severe visual field damage at presentation is the most important risk factor for later development of glaucoma blindness.

Effects of socioeconomic status on baseline values and outcomes at 24 months in the Treatment of Advanced Glaucoma Study randomised controlled Trial

BACKGROUND/AIMS

Socioeconomic status (SES) is associated with late disease presentation and poorer outcomes. We evaluate the effect of SES on treatment outcomes and report the correlation between SES and baseline characteristics of participants in the Treatment of Advanced Glaucoma Study.

METHODS

Pragmatic multicentre randomised controlled trial. Four hundred and fifty-three patients presenting with advanced open-angle glaucoma in at least one eye (Hodapp-Parrish-Anderson classification). Participants were randomised to either glaucoma drops (medical arm) or trabeculectomy (surgery arm). Clinical characteristics, Quality of life measurement (QoL) and SES defined by the Index of Multiple Deprivation are reported. Subgroup analysis explored treatment effect modifications of SES at 24 months. Correlation between SES and baseline characteristics was tested with the χ2 test of association for dichotomous variables and pairwise Pearson's correlation for continuous variables.

RESULTS

The mean visual field mean deviation was -17.2 (6.7)dB for the most deprived quintile of participants and -13.0 (5.5) for the least deprived quintile in the index eye. At diagnosis, there was a strong correlation between SES and ethnicity, age, extent of visual field loss and number of visits to opticians prior to diagnosis. At 24 months, there was no evidence that the treatment effect was moderated by SES.

CONCLUSIONS

In patients presenting with advanced glaucoma. SES at baseline is correlated with poorer visual function, poorer Visual Function Questionnaire-25 QoL, ethnicity, age and number visits to an optician in the years preceding diagnosis. SES at baseline does not have an effect of the success of treatment at 24 months.

TRIAL REGISTRATION NUMBER

ISRCTN56878850.

Striving Toward Better Eye Health Beyond Our Waiting Rooms: The LXXX Edward Jackson Memorial Lecture

PURPOSE

Visual impairment (VI) negatively impacts the quality of lives of individuals and the optimal health of populations, creating both human and financial costs. Yet, VI has not risen to a level that is considered a priority in population health. This analysis assesses the evidence currently available for strengthening the value proposition for eye health, particularly the demographic characteristics and patient-centered outcomes found in clinical research.

DESIGN

Retrospective cross-sectional analysis.

METHOD

Two searches of the AJO database were performed using relevant key words: Search 1 (S1): NEI-sponsored clinical trials (1970-2023); and Search 2 (S2): Quality of life (2018-2023). The Scopus Cite Score was used as a filter for each search, specifically ≥50 for S1 and ≥20 for S2.

RESULTS

Of the initial 466 articles found, 100 met the preestablished criteria. Age, sex, and race/ancestry/ethnicity were reported across glaucoma, retina, uveitis, cornea, and pediatrics subspecialties in 56% ± 9.7% of the articles; 37% ± 9.5% listed either age only or age, sex, or gender. The characterizations varied and subcategories were rarely reported. Only 2% of S1 and 25% of S2 noted patient-centered outcomes.

CONCLUSIONS

The characterization of study populations in the ophthalmic literature is limited by underreporting of patient-centered outcomes, useful for reaffirming the value of eye and vision health in population health. This analysis highlights the need for paying greater attention to more specific demographic categories and focusing more on patient-centered outcomes in clinical research.

Validation of the RCOphth and UKEGS glaucoma risk stratification tool 'GLAUC-STRAT-fast'

BACKGROUND/AIMS

The aim of this study was to validate the Glaucoma Risk Stratification Tool (GLAUC-STRAT-fast) currently recommended by the Royal College of Ophthalmologists for the risk stratification of patients with glaucoma in the UK National Health Service Hospital Eye Service.

METHODS

GLAUC-STRAT fast was applied to the LiGHT trial participants by risk-stratifying the worse eye of each patient at baseline and after 3 years of treatment. Metrics of disease severity or treatment intensity used for the validation were: increased number of monitoring visits or treatment escalations; needing a trabeculectomy; a reduction of >2 dB in visual field mean deviation (VF MD) during the monitoring period; identification of rapid VF loss on total (TD) and/or pattern deviation (PD). The proportion of eyes within each baseline stratum for each of the above markers was compared against the other strata, using a χ2 test for proportions.

RESULTS

There was an association between the baseline stratification and the number of treatment escalations needed to maintain the eye-specific target intraocular pressure (p=0.001), the number of visits needed throughout the 3-year follow-up period (p=0.001), the need for trabeculectomy (p<0.001) and absolute loss of MD over the course of the monitoring period (p<0.001). The rate of VF progression was not associated with baseline risk stratification for TD or PD progression (p≥0.007, with Bonferroni correction).

CONCLUSION

The GLAUC-STRAT fast tool is a useful tool for risk stratifying eyes with ocular hypertension or open angle glaucoma. Further research is needed to confirm and validate its applicability to more advanced glaucomas and generalisability to clinical use.

TRIAL REGISTRATION NUMBER

The LiGHT trial is registered at controlled-trials.com (ISRCTN32038223).

Five-Year Visual Field Outcomes of the HORIZON Trial

PURPOSE

To compare visual field (VF) progression between glaucoma patients receiving cataract surgery alone (CS) or with a Hydrus microstent (CS-HMS).

DESIGN

Post hoc analysis of VF data from the HORIZON multicenter randomized controlled trial.

METHODS

A total of 556 patients with glaucoma and cataract were randomized 2:1 to either CS-HMS (369) or CS (187) and followed up for 5 years. VF was performed at 6 months and then every year after surgery. We analyzed data for all participants with at least 3 reliable VFs (false positives < 15%). Average between-group difference in rate of progression (RoP) was tested using a Bayesian mixed model and a 2-sided Bayesian P value <.05 (main outcome). A multivariable model measured the effect of intraocular pressure (IOP). A survival analysis compared the probability of global VF sensitivity dropping by predefined cutoffs (2.5, 3.5, 4.5, and 5.5 dB) from baseline.

RESULTS

Data from 352 eyes in the CS-HMS arm and 165 in the CS arm were analyzed (2966 VFs). The mean RoP was -0.26 dB/y (95% credible interval -0.36, -0.16) for CS-HMS and -0.49 dB/y (95% credible interval -0.63, -0.34) for CS. This difference was significant (P = .0138). The difference in IOP only explained 17% of the effect (P < .0001). Five-year survival analysis showed an increased probability of VF worsening by 5.5 dB (P = .0170), indicating a greater proportion of fast progressors in the CS arm.

CONCLUSIONS

CS-HMS has a significant effect on VF preservation in glaucoma patients compared with CS alone, reducing the proportion of fast progressors.

The Definition of Glaucomatous Optic Neuropathy in Artificial Intelligence Research and Clinical Applications

OBJECTIVE

Although artificial intelligence (AI) models may offer innovative and powerful ways to use the wealth of data generated by diagnostic tools, there are important challenges related to their development and validation. Most notable is the lack of a perfect reference standard for glaucomatous optic neuropathy (GON). Because AI models are trained to predict presence of glaucoma or its progression, they generally rely on a reference standard that is used to train the model and assess its validity. If an improper reference standard is used, the model may be trained to detect or predict something that has little or no clinical value. This article summarizes the issues and discussions related to the definition of GON in AI applications as presented by the Glaucoma Workgroup from the Collaborative Community for Ophthalmic Imaging (CCOI) US Food and Drug Administration Virtual Workshop, on September 3 and 4, 2020, and on January 28, 2022.

DESIGN

Review and conference proceedings.

SUBJECTS

No human or animal subjects or data therefrom were used in the production of this article.

METHODS

A summary of the Workshop was produced with input and approval from all participants.

MAIN OUTCOME MEASURES

Consensus position of the CCOI Workgroup on the challenges in defining GON and possible solutions.

RESULTS

The Workshop reviewed existing challenges that arise from the use of subjective definitions of GON and highlighted the need for a more objective approach to characterize GON that could facilitate replication and comparability of AI studies and allow for better clinical validation of proposed AI tools. Different tests and combination of parameters for defining a reference standard for GON have been proposed. Different reference standards may need to be considered depending on the scenario in which the AI models are going to be applied, such as community-based or opportunistic screening versus detection or monitoring of glaucoma in tertiary care.

CONCLUSIONS

The development and validation of new AI-based diagnostic tests should be based on rigorous methodology with clear determination of how the reference standards for glaucomatous damage are constructed and the settings where the tests are going to be applied.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Contrast Sensitivity and Night Driving in Older People: Quantifying the Relationship Between Visual Acuity, Contrast Sensitivity, and Hazard Detection Distance in a Night-Time Driving Simulator

Purpose

(i) To assess how well contrast sensitivity (CS) predicts night-time hazard detection distance (a key component of night driving ability), in normally sighted older drivers, relative to a conventional measure of high contrast visual acuity (VA); (ii) To evaluate whether CS can be accurately quantified within a night driving simulator.

Materials and Methods

Participants were 15 (five female) ophthalmologically healthy adults, aged 55–81 years. CS was measured in a driving simulator using Landolt Cs, presented under static or dynamic driving conditions, and with or without glare. In the dynamic driving conditions, the participant was asked to simultaneously maintain a (virtual) speed of 60 km/h on a country road. In the with glare conditions, two calibrated LED arrays, moved by cable robots, simulated the trajectories and luminance characteristics of the (low beam) headlights of an approaching car. For comparison, CS was also measured clinically (with and without glare) using a Optovist I instrument (Vistec Inc., Olching, Germany). Visual acuity (VA) thresholds were also assessed at high and low contrast using the Freiburg Visual Acuity Test (FrACT) under photopic conditions. As a measure of driving performance, median hazard detection distance (MHDD) was computed, in meters, across three kinds of simulated obstacles of varying contrast.

Results

Contrast sensitivity and low contrast VA were both significantly associated with driving performance (both P < 0.01), whereas conventional high contrast acuity was not (P = 0.10). There was good correlation (P < 0.01) between CS measured in the driving simulator and a conventional clinical instrument (Optovist I). As expected, CS was shown to decrease in the presence of glare, in dynamic driving conditions, and as a function of age (all P < 0.01).

Conclusion

Contrast sensitivity and low contrast VA predict night-time hazard detection ability in a manner that conventional high contrast VA does not. Either may therefore provide a useful metric for assessing fitness to drive at night, particularly in older individuals. CS measurements can be made within a driving simulator, and the data are in good agreement with conventional clinical methods (Optovist I).

Cost-effectiveness of primary surgical versus primary medical management in the treatment of patients presenting with advanced glaucoma

SYNOPSIS

Advanced glaucoma is associated with sight loss. This within-trial economic evaluation compares medical and surgical management strategies. At 2 years, medication appears more cost-effective though longitudinal outcomes are an important subject in future research.

BACKGROUND/AIMS

Open angle glaucoma (OAG) is a progressive optic neuropathy. Approximately 25% of newly diagnosed patients with OAG present with advanced disease in at least one eye. The vision loss associated with OAG can lead to significant impacts on vision, quality of life and health care resources. The Treatment of Advanced Glaucoma Study is a randomised controlled trial comparing the effectiveness of primary surgical and medical management for newly diagnosed advanced patients with OAG. An economic evaluation was carried out to understand the costs and benefits of each strategy.

METHODS

A cost utility analysis was carried out from a National Health Service perspective over a 2-year time horizon inclusive of patient costs. The primary outcome was patient health-related quality of life measured by the EQ-5D-5L, Health Utilities Index 3 (HUI3) and Glaucoma Utility Index (GUI). Results were expressed as incremental cost per QALY gained.

RESULTS

Trabeculectomy was associated with higher costs and greater effect, the EQ-5D-5L results have an incremental cost per QALY of £45,456. The likelihood of surgery being cost-effective at a £20, 000, £30,000 and £50,000 QALY threshold is 0%, 12% and 56%, respectively. The results for the HUI3, GUI and inclusion of patient costs do not change the conclusions of the study.

CONCLUSION

This is the first study to evaluate management strategies for those presenting with advanced glaucoma. At a 2-year time horizon, medication is the more cost-effective approach for managing glaucoma. Future research can focus on the costs and benefits of the treatments over a longer time horizon.

Long-term Intraocular Pressure Fluctuation Is a Risk Factor for Visual Field Progression in Advanced Glaucoma

PRCIS

Intraocular pressure (IOP) fluctuations increase the risk of visual field progression of primary open-angle glaucoma (POAG) in the advanced stage even when IOP is maintained low on average.

PURPOSE

The purpose of this study was to identify risk factors associated with the progression of visual field defect in patients with advanced POAG.

MATERIALS AND METHODS

A retrospective review of medical records was conducted to identify patients who met the Hodapp-Parrish-Anderson criteria for advanced POAG. A total of 122 eyes of 122 patients had undergone IOP measurement with Goldmann applanation tonometer, standard automated perimetry, Cirrus optical coherence tomography, and fundus photography at 6-month intervals. Visual field progression was defined as the deterioration of a minimum of 3 visual field locations more than baseline at 5% levels in 4 consecutive visual fields with 24-2 SITA testing.

RESULTS

Thirty-six eyes of 122 eyes (29.5%, 51.9±13.9 y old) showed visual field progression during 100.7±44.2 months of follow-up. The progression group showed greater long-term IOP fluctuations (2.6±1.4 mm Hg) than the no progression group (53.5±13.5 y; 2.0±1.0 mm Hg, P=0.008). Disc hemorrhage was detected more frequently in the progression group (40.5% vs. 17.4%, P=0.005). Multivariate Cox regression analysis revealed long-term IOP fluctuations [hazard ratio (HR)=2.567, 95% confidence interval (CI): 1.327-5.370, P=0.012] and disc hemorrhage (HR=2.351, 95% CI: 1.120-4.931, P=0.024) to be independent risk factors of visual field progression. Patients who showed both disc hemorrhage and long-term IOP fluctuations were at greater risks of progression (HR=2.675, 95% CI: 1.072-6.457, P=0.035).

CONCLUSIONS

Long-term IOP fluctuations and disc hemorrhage are independent and additive risk factors of visual field progression in advanced glaucoma even at low IOPs. Patients in whom these risk factors are identified require close monitoring and vigorous treatment.

Path to Diagnosis and Clinical Characteristics of Advanced Glaucoma at Initial Diagnosis: a Tertiary Single Center Experience

Purpose: As routine health examinations become more common, many patients first diagnosed with glaucoma have advanced glaucoma. We analyzed the routes to diagnosis and the characteristics of patients initially diagnosed with advanced glaucoma.Methods: We retrospectively retrieved the medical records of patients first diagnosed with advanced glaucoma in our tertiary care center. The inclusion criteria were a mean deviation (MD) less than -12 dB on the visual field test, accompanied by structural damage. All patients were classified in terms of unilateral/bilateral disease, the intraocular pressure before medication, and lens status. We divided patients into those with monocular or binocular advanced glaucoma, high- or normal-pressure glaucoma, and those who were pseudophakic or phakic.Results: We included 73 patients of mean age 69.3 years. The visual field test MD was -19.6 dB. In those with binocular advanced glaucoma, incidental ophthalmic examination was the most common means of diagnosis (52.2%). Central-island visual field defects were the most common defects (54.2%). In those with monocular advanced glaucoma, glaucoma-associated symptoms most commonly triggered diagnosis (46.9%). Both superior and inferiorvisual field defects were the most common defects (42.8%). Glaucoma-associated symptoms were present in 68.2 and 22.8% of patients with high- and normal-pressure glaucoma, respectively. Central-island visual field defects were present in 43.6 and 29.4% of those with high- and normal-pressure glaucoma, respectively.Conclusions: We analyzed the routes to diagnosis and the clinical characteristics of patients with advanced glaucoma. In those with binocular disease, glaucoma was most commonly diagnosed on incidental ophthalmic examination. Central-island visual field defects were the most common defects in patients with binocular and high-pressure glaucoma, and the pseudophakic group. A multi-center longitudinal study on risk factors for delayed glaucoma diagnosis is needed.

The Frontloading Fields Study (FFS): Detecting Changes in Mean Deviation in Glaucoma Using Multiple Visual Field Tests Per Clinical Visit

Purpose

To determine the impact of different numbers of visual field tests per visit for detecting mean deviation changes over time in patients with early glaucoma or suspected glaucoma and to identify a practical approach to maximize change detection.

Methods

Intrasession (n = 322) and intersession (n = 323) visual field results for patients with glaucoma or suspected glaucoma were used to model mean deviation change in 10,000 progressing and 10,000 non-progressing computer-simulated patients over time. Variables assessed in the model included follow-up intervals (0.5, 1, or 2 years), reliability rates (70%, 85%, or 100%) and number of visual field tests performed at each visit (one to four).

Results

Two visual field tests per session compared with one provided higher case detection rates at 2 years (99%–99.8% vs. 34.7%–76.3%, respectively), reduced time to detection (three or four visits vs. six to 10, respectively), and more positive mean deviation score (−4 dB vs. −10 dB, respectively) at the point of mean deviation change identification, especially in the context of unreliable results. Performing two tests per visit offered similar advantages compared with more tests. False positive change detection rates (<2.5%), were similar across all conditions. Patients followed up 6 monthly had less severe mean deviation loss at follow-up compared to 1-year and 2-year follow-up intervals.

Conclusions

Performing two tests per clinical visit at 6 months is practical using SITA-Faster and provides higher detection rates of mean deviation change in comparison with only one test performed per visit and more spaced-out intervals.

Translational Relevance

This model provides guidance for selecting the number of tests per visit to detect mean deviation change.

Hierarchical Censored Bayesian Analysis of Visual Field Progression

Purpose

To develop a Bayesian model (BM) for visual field (VF) progression accounting for the hierarchical, censored and heteroskedastic nature of the data.

Methods

Three versions of a hierarchical BM were developed: a simple linear (Hi-linear); censored at 0 dB (Hi-censored); heteroskedastic censored (Hi-HSK). For the latter, we modeled the test variability according to VF sensitivity using a large test-retest cohort (1396 VFs, 146 eyes with glaucoma). We analyzed a large cohort of 44,371 VF tests from 3352 eyes from five glaucoma clinics. We quantified the bias in the estimated rate-of-progression, the detection of progression (Hit-rate [HR]), the median time-to-progression and the prediction error of future observations (mean absolute error [MAE]). HR and time-to-progression were compared at matched false-positive-rate (FPR), quantified using permutations of a separate test-retest cohort (360 tests, 30 eyes with glaucoma). BMs were compared to simple linear regression and Permutation-Analyses-of Pointwise-Linear-Regression. Differences in time-to-progression were tested using survival analysis.

Results

Censored models showed the smallest bias in the rate-of-progression. The three BMs performed very similarly in terms of HR and time-to-progression and always better than the other methods. The average reduction in time-to-progression was 37% with the BMs (P < 0.001) at 5% FPR. MAE for prediction was very similar among methods.

Conclusions

Bayesian hierarchical models improved the detection of VF progression. Accounting for censoring improves the precision of the estimates, but minimal effect is provided by accounting for heteroskedasticity.

Translational Relevance

These results are relevant for quantification of VF progression in practice and for clinical trials.

Improving the Power of Glaucoma Neuroprotection Trials Using Existing Visual Field Data

PURPOSE

Selecting reliable visual field (VF) test takers could improve the power of randomized clinical trials in glaucoma. We test this hypothesis via simulations using a large real world data set.

DESIGN

Methodology analysis: assessment of how improving reliability affects sample size estimates.

METHODS

A variability index (VI) estimating intertest variability was calculated for each subject using the residuals of the regression of the mean deviation over time for the first 6 tests in a series of at least 10 examinations for 2,804 patients. Using data from the rest of the series, we simulate VFs at regular intervals for 2 years. To simulate the neuroprotective effect (NE), we reduced the observed progression rate by 20%, 30%, or 50%. The main outcome measure was the sample size to detect a significant difference (P < .05) at 80% power.

RESULTS

In the first experiment, we simulated a trial including one eye per subject, either selecting randomly from the database or prioritizing patients with low VI. We could not reach 80% power for the low NE with the available patients, but the sample size was reduced by 38% and 49% for the 30% and 50% NE, respectively. In the second experiment, we simulated 2 eyes per subject, one of which was the control eye. The sample size (smaller overall) was reduced by 26% and 38% for the 30% and 50% NE by prioritizing patients with low VI.

CONCLUSIONS

Selecting patients with low intertest variability can significantly improve the power and reduce the sample size needed in a trial.

Primary trabeculectomy for advanced glaucoma: pragmatic multicentre randomised controlled trial (TAGS)

OBJECTIVE

To determine whether primary trabeculectomy or primary medical treatment produces better outcomes in term of quality of life, clinical effectiveness, and safety in patients presenting with advanced glaucoma.

DESIGN

Pragmatic multicentre randomised controlled trial.

SETTING

27 secondary care glaucoma departments in the UK.

PARTICIPANTS

453 adults presenting with newly diagnosed advanced open angle glaucoma in at least one eye (Hodapp classification) between 3 June 2014 and 31 May 2017.

INTERVENTIONS

Mitomycin C augmented trabeculectomy (n=227) and escalating medical management with intraocular pressure reducing drops (n=226) MAIN OUTCOME MEASURES: Primary outcome: vision specific quality of life measured with Visual Function Questionnaire-25 (VFQ-25) at 24 months.

SECONDARY OUTCOMES

general health status, glaucoma related quality of life, clinical effectiveness (intraocular pressure, visual field, visual acuity), and safety.

RESULTS

At 24 months, the mean VFQ-25 scores in the trabeculectomy and medical arms were 85.4 (SD 13.8) and 84.5 (16.3), respectively (mean difference 1.06, 95% confidence interval -1.32 to 3.43; P=0.38). Mean intraocular pressure was 12.4 (SD 4.7) mm Hg for trabeculectomy and 15.1 (4.8) mm Hg for medical management (mean difference -2.8 (-3.8 to -1.7) mm Hg; P<0.001). Adverse events occurred in 88 (39%) patients in the trabeculectomy arm and 100 (44%) in the medical management arm (relative risk 0.88, 95% confidence interval 0.66 to 1.17; P=0.37). Serious side effects were rare.

CONCLUSION

Primary trabeculectomy had similar quality of life and safety outcomes and achieved a lower intraocular pressure compared with primary medication.

TRIAL REGISTRATION

Health Technology Assessment (NIHR-HTA) Programme (project number: 12/35/38). ISRCTN registry: ISRCTN56878850.

Vision, attention, and driving

Safe driving demands the coordination of multiple sensory and cognitive functions, such as vision and attention. Patients with neurologic or ophthalmic disease are exposed to selective pathophysiologic insults to driving-critical systems, placing them at a higher risk for unsafe driving and restricted driving privileges. Here, we evaluate how vision and attention contribute to unsafe driving across different patient populations. In ophthalmic disease, we focus on macular degeneration, glaucoma, diabetic retinopathy, and cataract; in neurologic disease, we focus on Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Unsafe driving is generally associated with impaired vision and attention in ophthalmic and neurologic patients, respectively. Furthermore, patients with ophthalmic disease experience some degree of impairment in attention. Similarly, patients with neurologic disease experience some degree of impairment in vision. While numerous studies have demonstrated a relationship between impaired vision and unsafe driving in neurologic disease, there remains a dearth of knowledge regarding the relationship between impaired attention and unsafe driving in ophthalmic disease. In summary, this chapter confirms-and offers opportunities for future research into-the contribution of vision and attention to safe driving.

What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss

Purpose

Glaucoma patients with peripheral vision loss have in the past subjectively described their field loss as ‘blurred’ or ‘no vision compromise’. We developed an iPad app for patients to self-characterise perception within areas of glaucomatous visual field loss.

Methods

Twelve glaucoma patients with visual acuity ≥20/40 in each eye, stable and reliable Humphrey Visual Field (HVF) over 2 years were enrolled. An iPad app (held at 33 cm) allowed subjects to modify ‘blur’ or ‘dimness’ to match their perception of a 2×2 m wall-mounted poster at 1 m distance. Subjects fixated at the centre of the poster (spanning 45° of field from centre). The output was degree of blur/dim: normal, mild and severe noted on the iPad image at the 54 retinal loci tested by the HVF 24-2 and was compared to threshold sensitivity values at these loci. Monocular (Right eye (OD), left eye (OS)) HVF responses were used to calculate an integrated binocular (OU) visual field index (VFI). All three data sets were analysed separately.

Results

36 HVF and iPad responses from 12 subjects (mean age 71±8.2y) were analysed. The mean VFI was 77% OD, 76% OS, 83% OU. The most common iPad response reported was normal followed by blur. No subject reported dim response. The mean HVF sensitivity threshold was significantly associated with the iPad response at the corresponding retinal loci (For OD, OS and OU, respectively (dB): normal: 23, 25, 27; mild blur: 18, 16, 22; severe blur: 9, 9, 11). On receiver operative characteristic (ROC) curve analysis, the HVF retinal sensitivity cut-off at which subjects reported blur was 23.4 OD, 23 OS and 23.3 OU (dB).

Conclusions

Glaucoma subjects self-pictorialised their field defects as blur; never dim or black. Our innovation allows translation of HVF data to quantitatively characterise visual perception in patients with glaucomatous field defects.

Baseline Characteristics of Participants in the Treatment of Advanced Glaucoma Study: A Multicenter Randomized Controlled Trial

PURPOSE

To report the baseline characteristics of participants enrolled in TAGS (Treatment of Advanced Glaucoma Study).

DESIGN

Pragmatic randomized control trial (RCT).

METHODS

Participants with newly diagnosed advanced glaucoma in at least 1 eye were recruited. Participants were patients with open angle glaucoma presenting with advanced glaucoma in at least 1 eye as defined by the Hodapp-Parrish-Anderson (HPA) criteria for severe defect. Participants were randomly allocated to receive either primary augmented trabeculectomy or primary medical management. When both eyes were eligible, the same intervention was undertaken in both eyes, and the index eye for analysis was the eye with the less severe visual field mean defect (MD). Main outcome measurements were visual field profile, defined by the HPA classification; clinical characteristics; quality of life, as measured by the National Eye Institute Visual Function Questionnaire 25 (VFQ-25), the EuroQual-5 Dimension (EQ-5D 5L), Health Utility Index-3 (HUI-3), and the Glaucoma Profile Instrument (GPI).

RESULTS

A total of 453 patients were recruited. The mean visual field MD was -15.0 dB ± 6.3 in the index eye and -6.2 dB in the non-index eye. Of index eyes (HPA "severe" classification) at baseline, more than 70% of participants had a MD <-12.00 dB, and nearly 90% had more than 20 points defective at the 1% level. The mean LogMAR visual acuity of the index eye was 0.2 ± 0.3.

CONCLUSIONS

TAGS is the first RCT to compare medical versus surgical treatments for patients presenting with advanced open angle glaucoma in a publicly funded health service. The study will provide clinical, health-related quality of life, and economic outcomes to inform future treatment choices for those presenting with advanced glaucoma.

Role of advanced technology in the detection of sight-threatening eye disease in a UK community setting

Background/aims

To determine the performance of combinations of structural and functional screening tests in detecting sight-threatening eye disease in a cohort of elderly subjects recruited from primary care.

Methods

505 subjects aged ≥60 years underwent frequency doubling technology (FDT) perimetry, iVue optical coherence tomography (iWellness and peripapillary retinal nerve fibre layer (RNFL) scans) and intraocular pressure with the Ocular Response Analyzer, all performed by an ophthalmic technician. The reference standard was a full ophthalmic examination by an experienced clinician who was masked to the index test results. Subjects were classified as presence or absence of sight-threatening eye disease (clinically significant cataract, primary open-angle glaucoma, intermediate or advanced age-related macular degeneration and significant diabetic retinopathy). Univariate and multivariate logistic regression analyses were used to determine the association between abnormal screening test results and the presence of sight-threatening eye disease.

Results

171 subjects (33.8%) had one or more sight-threatening eye diseases. The multivariate analysis found significant associations with any of the target conditions for visual acuity of <6/12, an abnormal FDT and peripapillary RNFL thickness outside the 99% normal limit. The sensitivity of this optimised screening panel was 61.3% (95% CI 53.5 to 68.7), with a specificity of 78.8% (95% CI 74.0 to 83.1), a positive predictive value of 59.5% (95% CI 53.7 to 65.2) and an overall diagnostic accuracy of 72.9% (95% CI 68.8 to 76.8).

Conclusions

A subset of screening tests may provide an accurate and efficient means of population screening for significant eye disease in the elderly. This study provides useful preliminary data to inform the development of further larger, multicentre screening studies to validate this screening panel.

Advanced glaucoma at diagnosis: current perspectives

Presentation with advanced glaucoma is a significant risk factor for lifetime blindness. The asymptomatic nature of glaucoma, particularly in early disease, means that substantial vision loss in one eye does not always translate into a perceptible loss of visual function. This, along with the lack of an effective screening strategy, contributes to late presentation. Those most at risk of presenting with advanced glaucoma have asymptomatic high intraocular pressure (IOP), no family history of glaucoma, are socially disadvantaged, and do not attend sight testing. Patients with glaucoma may have impaired functionality for daily activities, such as reading, walking and driving. Quality of life measures have shown this to be significantly worse in patients with more severe visual field loss, particularly if bilateral. In addition, quality of life decreases faster with further bilateral visual field loss when advanced visual field damage is present. Management of these patients requires disproportionally more resources than those with earlier disease. Both medical and surgical options are used as the initial approach to treat patients presenting with advanced glaucoma. The most recently published National Institute for Health and Care Excellence (NICE) guidelines suggest that patients presenting with advanced disease should be offered trabeculectomy as a primary intervention. However, more evidence is required to determine the best initial management. The Treatment of Advanced Glaucoma Study (TAGS) is being conducted, comparing primary medical management with primary mitomycin C-augmented trabeculectomy for people presenting with advanced open-angle glaucoma. The results of TAGS will provide robust evidence for the most appropriate initial intervention.

Auditing service delivery in glaucoma clinics using visual field records: a feasibility study

Objective

This study aimed to demonstrate that large-scale visual field (VF) data can be extracted from electronic medical records (EMRs) and to assess the feasibility of calculating metrics from these data that could be used to audit aspects of service delivery of glaucoma care.

Method and analysis

Humphrey visual field analyser (HFA) data were extracted from Medisoft EMRs from five regionally different clinics in England in November 2015, resulting in 602 439 records from 73 994 people. Target patients were defined as people in glaucoma clinics with measurable and sustained VF loss in at least one eye (HFA mean deviation (MD) outside normal limits ≥2 VFs). Metrics for VF reliability, stage of VF loss at presentation, speed of MD loss, predicted loss of sight years (bilateral VF impairment) and frequency of VFs were calculated.

Results

One-third of people (34.8%) in the EMRs had measurable and repeatable VF loss and were subject to analyses (n=25 760 patients). Median (IQR) age and presenting MD in these patients were 71 (61, 78) years and −6 (–10, –4) dB, respectively. In 19 264 patients with >4 years follow-up, median (IQR) MD loss was −0.2 (−0.8, 0.3) dB/year and median (IQR) intervals between VF examinations was 11 (8, 16) months. Metrics predicting loss of sight years and reliability of examinations varied between centres (p<0.001).

Conclusion

This study illustrates the feasibility of assessing aspects of health service delivery in glaucoma clinics through analysis of VF databases. Proposed metrics could be useful for blindness prevention from glaucoma in secondary care centres.

Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania

Purpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania.Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity.Results: In Tanzania, 44.7% {CI_95%: 42.2, 47.2} of patients presented with severe VF loss (< -20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18-65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women.Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids.

Remote Grading of the Anterior Chamber Angle Using Goniophotographs and Optical Coherence Tomography: Implications for Telemedicine or Virtual Clinics

PURPOSE

To evaluate the agreement and accuracy of grading goniophotographs and anterior segment optical coherence tomography (AS-OCT) results for assessment of the anterior chamber angle, and elicit factors driving concordance between perceived grade and ground truth.

METHODS

Three clinicians evaluated the goniophotographs and AS-OCT results of 75 patients. Graders' impressions of the angle grade, trabecular pigmentation, and iris contour were compared with the ground truth gonioscopic examination result when physically performed by a senior optometrist. Percentage agreement and kappa statistics were calculated. Binary logistic regression was used to elicit factors for accurate grading.

RESULTS

Exact angle matches and binary (open or closed) evaluations were above guessing rate for all graders. There was a systematic bias toward underestimating the angle structure across all graders, especially at the superior angle, by approximately 1 ordinal unit. Kappa statistics showed fair-moderate agreement for exact (0.387-0.520) and binary (0.347-0.520) angle evaluations. Agreement was unchanged when using a multimodal approach (0.373-0.523). Factors driving concordance were primarily related to the extremes of the anterior chamber angle configuration (shallow or deep structures, and iris contour). However, prediction models did not fully explain the levels of concordance with the ground truth (maximum R 2 amongst models 0.177).

CONCLUSIONS

Although moderate agreement between graders and ground truth could be obtained under binary evaluations, angle grades were generally underestimated. Factors affecting concordance were primarily the extremes of the ground truth angle and iris contour.

TRANSLATIONAL RELEVANCE

We highlight factors affecting accuracy of grading goniophotography and AS-OCT images of the anterior chamber angle.

Does eye examination order for standard automated perimetry matter?

Purpose

In spite of faster examination procedures, visual field (VF) results are potentially influenced by fatigue. We use large‐scale VF data collected from clinics to test the hypothesis that perimetric fatigue effects are greater in the eye examined second.

Methods

Series of six Humphrey Swedish Interactive Testing Algorithm (SITA) VFs from 6901 patients were retrospectively extracted from a VF database from four different glaucoma clinics. Mean deviation (MD) was compared between first and second tested eyes. A surrogate measure of longitudinal MD variability over time was estimated from errors using linear regression of MD against time then compared between first and second tested eye.

Results

Right eye VF was tested consistently first throughout in 6320 (91.6%) patients. Median (interquartile range; IQR) MD in the first tested (right) eye and second tested (left) eye was −2.57 (−6.15, −0.58) dB and −2.70 (−6.34, −0.80) dB respectively (median reduction VF sensitivity of 0.13 dB; p < 0.001). Median (IQR) increase in our surrogate measure of longitudinal MD variability in the second eye tested was 3% (−43%, 50%); this effect was not associated with patient age or rest time between examinations.

Conclusion

Statistically significant perimetric fatigue effects manifest on average in the second eye tested in routine clinics using Humphrey Field Analyzer SITA examinations. However, the average effects were very small and there was enormous variation among patients. We recommend starting with a right eye examination so that any perimetric fatigue effects, if they exist in an individual, will be as constant as possible from visit to visit.

OCT Circle Scans Can Be Used to Study Many Eyes with Advanced Glaucoma

Purpose

To examine the utility of optical coherence tomography (OCT) for studying eyes with advanced glaucoma [i.e., eyes with a 24-2 visual field (VF) mean deviation (MD) worse than -15 dB], we tested the hypothesis that if these eyes had a 10-2 total deviation (TD) map with points better than -8 dB, then the topographically corresponding regions on the circumpapillary retinal nerve fiber layer (cpRNFL) should show a preserved region.

Design

Evaluation of technology study.

Participants

39 eyes from 33 patients (mean: 68.8 ± 9.2 years) with a diagnosis of glaucoma had a 24-2 VF with a MD ≤ -15 dB (mean: -18.94 ± 2.95 dB). All eyes additionally had a 10-2 VF and an averaged OCT circle scan.

Methods

Each scan was inspected, and preserved cpRNFL regions of the disc associated with the macula (central ±8° were delin eated.

Main Outcome Measures

The number of eyes with preserved cpRNFL regions and their association with preserved VF locations (i.e. better than -8 dB) shown in the 10-2 VF TD map.

Results

38 of the 39 eyes had one or more points on the 10-2 VF with TD values that were better than -8 dB (mean: 25.7 ± 12.6 points). For all 39 eyes, there was a preserved portion of the cpRNFL on the circle scan within the disc region associated with the macula. However, for 3 of these eyes, this region was hypodense and could be a challenge for the clinician to identify.

Conclusion

OCT scans can be used to assess and potentially follow the preserved regions of cpRNFL associated with the macula in eyes with advanced glaucoma if there is a preserved region on the 10-2 VF better than -8 dB.

Portable Perimetry Using Eye-Tracking on a Tablet Computer-A Feasibility Assessment

Purpose

Visual field (VF) examination by standard automated perimetry (SAP) is an important method of clinical assessment. However, the complexity of the test, and its use of bulky, expensive equipment makes it impractical for case-finding. We propose and evaluate a new approach to paracentral VF assessment that combines an inexpensive eye-tracker with a portable tablet computer (“Eyecatcher”).

Methods

Twenty-four eyes from 12 glaucoma patients, and 12 eyes from six age-similar controls were examined. Participants were tested monocularly (once per eye), with both the novel Eyecatcher test and traditional SAP (HFA SITA standard 24-2). For Eyecatcher, the participant's task was to simply to look at a sequence of fixed-luminance dots, presented relative to the current point of fixation. Start and end fixations were used to determine locations where stimuli were seen/unseen, and to build a continuous map of sensitivity loss across a VF of approximately 20°.

Results

Eyecatcher was able to clearly separate patients from controls, and the results were consistent with those from traditional SAP. In particular, mean Eyecatcher scores were strongly correlated with mean deviation scores (r² = 0.64, P < 0.001), and there was good concordance between corresponding VF locations (∼84%). Participants reported that Eyecatcher was more enjoyable, easier to perform, and less tiring than SAP (all P < 0.001).

Conclusions

Portable perimetry using an inexpensive eye-tracker and a tablet computer is feasible, although possible means of improvement are suggested.

Translational Relevance

Such a test could have significant utility as a case finding device.

Twenty-year outcomes in patients with newly diagnosed glaucoma: mortality and visual function

Background/aims

To determine the mortality within 20 years of diagnosis of chronic open-angle glaucoma (COAG) and visual acuity and visual field progression of a cohort followed for 20 years.

Methods

Twenty years following the diagnosis of COAG in 68 of 436 (16%) patients seen in a glaucoma case-finding clinic, visual and mortality outcomes were audited from medical records. Causes of death were obtained from general practitioner records and death certificates. Probability of death was calculated using a Kaplan-Meier survival curve. The visual field of each eye of survivors was graded using a nine-stage severity scale. Visual outcome was analysed at the 20-year follow-up visit.

Results

From 68, 14 (21%) were lost to follow-up. In the remaining 54, 20 (37%) were alive 20 years after diagnosis. Of 63% who died, mean age of death was 84 years, most commonly due to vascular disease. Mean age at presentation of those who died was 73.7 years versus 63.2 years for survivors (P=0.001). The median time to death was 16 years. On visual field analysis, nearly half (48.9%) of eyes did not deteriorate, but 28.3% eyes deteriorated by more than two stages. Those who died had worse final visual acuity than survivors (P<0.001). Three who died were registered severely visually impaired mainly from macular disease, but no survivors were registered (P<0.001).

Conclusion

In this cohort, approximately two-thirds of patients with glaucoma died within 20 years of diagnosis. In most older patients with glaucoma, the overall goal of preventing visual handicap and blindness is achievable 20 years after diagnosis.

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.

A New Graphical Tool for Assessing Visual Field Progression in Clinical Populations

Purpose

We demonstrate a new approach for assessing and visualizing visual field (VF) progression in clinics.

Methods

Two summary measures for VF progression, Rate of Progression (RP) and Loss of Sight Years (LSY), are combined with a novel visualization (Hedgehog Plots). RP is calculated per eye using linear regression of mean deviation (MD) against time of follow-up. LSY is a novel parameter, linked to actuarial data, which estimates the number of years that a patient will have advanced bilateral VF loss in their predicted remaining lifetime. Every eye is given a rank within the sample based on RP and LSY allowing for “priority” patients to be identified. We illustrate differences between the parameters with an experiment comparing the cases flagged as “priority” by each method using data from 1263 VF records.

Results

RP for every eye in a “clinic” can be visualized and assessed using a Hedgehog Plot. Eyes are ranked against all other eyes by RP and LSY; these parameters provide different and complementary information on a patient's VF progression status. A purpose written interactive application demonstrating the techniques is available in the public domain at https://crabblab.shinyapps.io/hedgehog.

Conclusion

Hedgehog Plots provide a tool for visualizing VF progression in groups of patients and can be used potentially to prioritize monitoring resources.

Translational Relevance

This study illustrates a novel visualization technique and an interactive application that can be used to help determine VF progression in large groups of patients.

Example of monitoring measurements in a virtual eye clinic using ‘big data’

Aim

To assess the equivalence of measurement outcomes between patients attending a standard glaucoma care service, where patients see an ophthalmologist in a face-to-face setting, and a glaucoma monitoring service (GMS).

Methods

The average mean deviation (MD) measurement on the visual field (VF) test for 250 patients attending a GMS were compared with a ‘big data’ repository of patients attending a standard glaucoma care service (reference database). In addition, the speed of VF progression between GMS patients and reference database patients was compared. Reference database patients were used to create expected outcomes that GMS patients could be compared with. For GMS patients falling outside of the expected limits, further analysis was carried out on the clinical management decisions for these patients.

Results

The average MD of patients in the GMS ranged from +1.6dB to −18.9dB between two consecutive appointments at the clinic. In the first analysis, 12 (4.8%; 95% CI 2.5% to 8.2%) GMS patients scored outside the 90% expected values based on the reference database. In the second analysis, 1.9% (95% CI 0.4% to 5.4%) GMS patients had VF changes outside of the expected 90% limits.

Conclusions

Using ‘big data’ collected in the standard glaucoma care service, we found that patients attending a GMS have equivalent outcomes on the VF test. Our findings provide support for the implementation of virtual healthcare delivery in the hospital eye service.

Prospective study of glaucoma referrals across Europe: are we using resources wisely?

BACKGROUND

To investigate the outcomes of glaucoma referrals across different European countries.

METHODS

250 patients newly referred to tertiary referral glaucoma specialist practices in the UK, Hungary, Slovenia, Italy and Greece were prospectively enrolled (50 consecutive patients per centre). Referral accuracy and predictive value of referral criteria for an intervention or further monitoring (positive predictive value) were analysed.

RESULTS

Same-day discharges occurred in 43% (95% CI 39% to 75%) (12/28) of optometrist-initiated referrals (UK only), 37% (95% CI 30% to 45%) (59/158) of ophthalmologist-initiated referrals (all centres) and 54% (95% CI 40% to 68%) (26/48) of self-referrals (Hungary, Italy and Greece). The percentages from all referral sources were 46% (95% CI 32% to 60%) in the UK, 56% (95% CI 44% to 70%) in Hungary, 30% (95% CI 17% to 43%) in Slovenia, 22% (95% CI 11% to 34%) in Italy and 60% (95% CI 46% to 74%) in Greece (p<0.001). Overall, the referring criterion was confirmed in 54% (95% CI 45% to 63%) (64/119) for intraocular pressure (IOP) >21 mm Hg, 56% (95% CI 43% to 69%) (33/59) for a suspicious optic disc and 61% (95% CI 45% to 77%) (22/36) for a suspicious visual field, with large between-country differences (p<0.05 for all comparisons). Of all referrals, 32% (95% CI 26% to 37%) were initiated on the basis of IOP >21 mm Hg only. By combining the IOP criterion with any other referring criterion, the positive predictive value increased from 56% (95% CI 45% to 67%) to at least 89% (95% CI 68% to 100%). In the UK, a hypothetical IOP threshold of >26 mm Hg, as a requirement for IOP-only referrals, would reduce IOP-only referrals by 44%, while not missing any definite glaucoma cases.

CONCLUSION

The accuracy of referrals was poor in the UK and the other countries. Requiring a combination of criteria and raising the IOP threshold for IOP-only referrals are needed to cut waste in clinical care.

More frequent, more costly? Health economic modelling aspects of monitoring glaucoma patients in England

BACKGROUND

Chronic open angle glaucoma (COAG) is an age-related eye disease causing irreversible loss of visual field (VF). Health service delivery for COAG is challenging given the large number of diagnosed patients requiring lifelong periodic monitoring by hospital eye services. Yet frequent examination better determines disease worsening and speed of VF loss under treatment. We examine the cost-effectiveness of increasing frequency of VF examinations during follow-up using a health economic model.

METHODS

Two different VF monitoring schemes defined as current practice (annual VF testing) and proposed practice (three VF tests per year in the first 2 years after diagnosis) were examined. A purpose written health economic Markov model is used to test the hypothesis that cost effectiveness improves by implementing proposed practice on groups of patients stratified by age and severity of COAG. Further, a new component of the model, estimating costs of visual impairment, was added. Results were derived from a simulated cohort of 10000 patients with quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) used as main outcome measures.

RESULTS

An ICER of £21,392 per QALY was derived for proposed practice improving to a value of £11,382 once savings for prevented visual impairment was added to the model. Proposed practice was more cost-effective in younger patients. Proposed practice for patients with advanced disease at diagnosis generated ICERs > £60,000 per QALY; these cases would likely be on the most intensive treatment pathway making clinical information on speed of VF loss redundant. Sensitivity analysis indicated results to be robust in relation to hypothetical willingness to pay threshold identified by national guidelines, although greatest uncertainty was allied to estimates of implementation and visual impairment costs.

CONCLUSION

Increasing VF monitoring at the earliest stages of follow-up for COAG appears to be cost-effective depending on reasonable assumptions about implementation costs. Our health economic model highlights benefits of stratifying patients to more or less monitoring based on age and stage of disease at diagnosis; a prospective study is needed to prove these findings. Further, this works highlights gaps in knowledge about long term costs of visual impairment.

[Glaucoma-a common disease]

Glaucoma is the second leading cause of blindness worldwide. The purpose of this paper is to give a review on the epidemiology of the disease, on the importance and the consequences of glaucoma for people regarding their daily life, their ability to work, and quality of life.

A view on glaucoma--are we seeing it clearly?

Successful clinical management of glaucoma should not simply be about control of intraocular pressure, but must equate to correct decisions about intensifying treatment when patients are at risk of developing 'visual disability'. Yet little is known about what visual field defects, at different stages of glaucoma, specifically affect patients' abilities to perform everyday visual tasks. One way to do this is to measure patient performance in tasks in a lab setting. Another way is to ask patients themselves. The latter can be revealing and demystify views about how patients perceive the world. This short commentary highlights some of the current research in this area.

Are rates of vision loss in patients in English glaucoma clinics slowing down over time? Trends from a decade of data

PURPOSE

To examine changes in rates of visual field (VF) progression in patients attending a sample of glaucoma clinics in England between 1999 and 2012.

METHODS

An archive of 473 252 Humphrey VFs recorded across the UK was retrospectively examined. Distribution of rates recorded in the first half of the decade was compared with the second. The relationship between age and severity of MD loss at baseline with rates of loss and frequency of testing was examined.

RESULTS

VF series from 18 926 eyes were analysed. Median rate of MD loss for the period before and after 2003 was -0.11 and -0.06 dB/year, respectively, but the proportion of eyes with medium or fast rates of MD loss remained constant. Median rate of MD loss in older (>70 years) eyes was faster than that observed in younger (<60 years) eyes (-0.21 compared with -0.01 dB/year). Median rate of loss did not vary with severity of MD loss at baseline. Frequency of testing, typically carried out annually, did not vary by age, rate of loss or disease severity.

CONCLUSIONS

VFs of eyes treated in the first half of the decade deteriorated more rapidly than those in the second half. Several factors might explain these differences but average effects were small and there was no reduction in the proportion of rapidly progressing eyes over the decade. Older age and, to a lesser extent, worse VF damage at diagnosis are indicators for faster VF loss in clinics, but frequency of VF testing was similar for all patients.