The rate of progression of scotomas in glaucoma

Visual Field Progression in the Ocular Hypertension Treatment Study

PURPOSE

To determine the rate of visual field (VF) loss before and after the diagnosis of primary open angle glaucoma (POAG) in the Ocular Hypertension Treatment Study (OHTS).

DESIGN

Prespecified analyses of data collected prospectively in a clinical trial with extended follow-up.

SETTING AND PARTICIPANTS

Participants who developed POAG during OHTS 1 and 2 (February 1994 to December 2008) constitute an inception cohort. Follow-up data were collected in OHTS 3 (January 2016-April 2019). Analyses were performed from July 2021 to August 2022.

INTERVENTION

In OHTS 1 and 2, visual field (VF) tests were performed every 6 months and stereoscopic optic disc photographs were taken every 12 months. These tests were repeated in OHTS 3.

MAIN OUTCOMES AND MEASURES

Slopes of mean deviation (MD) were calculated by linear regression for all eyes in OHTS 1 and 2: eyes that did not develop POAG, eyes that developed optic disc POAG only, and eyes that developed VF POAG with/without optic disc POAG. Mean pre- and post-POAG slopes were calculated for eyes with a minimum of 5 VFs for each period.

RESULTS

Mean age at diagnosis of POAG was 66.4 ± 9.5 SD years (n = 282 participants), (56%) were male, 61% were White non-Hispanic and 32% were Black not Hispanic by self-report. The post-POAG slope was -0.40 ± 0.64 SD dB/year for all POAG eyes (n = 280 eyes), -0.19 ± 0.4 SD dB/yr. for optic disc POAG only eyes (n = 112 eyes), and -0.54 ± 0.7 SD dB/yr. for VF POAG eyes with or without optic disc POAG (n = 168 eyes). Among the VF POAG eyes, 69 (41%) had post-POAG MD slopes worse than or equal to -0.5 dB/year, 35 (21%) had slopes worse than or equal to -1.0 dB/year, and 9 (5.4%) had slopes worse than or equal to -2.0 dB/year.

CONCLUSIONS AND RELEVANCE

Some participants in OHTS had rapid rates of VF loss in one or both eyes despite being followed in a clinical study. This emphasizes that ocular hypertensive patients require careful follow-up, especially those at high risk of developing POAG to ensure early diagnosis and appropriate treatment of POAG.

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.

Longitudinal evaluation of advanced glaucoma: ten year follow-up cohort study

This study focused on patients with advanced open-angle glaucoma (OAG) and aimed to identify key factors for monitoring them. We included 127 such patients who were followed for seven years or more, undergoing annual ophthalmic examinations. Glaucoma progression was defined as a deterioration in either structure or function. The progression rates and risk factors were evaluated. The patients were divided into upper- and lower-half subgroups based on the reduction in intraocular pressure (IOP) from the baseline. Over an 11-year period, glaucoma progression was detected in 59 eyes (46.5%). The rate of change in mean deviation (MD) was - 0.43 dB/year for the entire population; - 0.67 dB/year for progressors; and - 0.20 dB/year for non-progressors. Hypertension and disc hemorrhage (DH) were more common in progressors compared to non-progressors (45.8 vs. 23.5%, 11.9 vs. 1.5%; P = 0.008 and P = 0.016). Multivariate Cox's proportional hazard model revealed that the presence of DH and a better baseline MD were associated with glaucoma progression. Additionally, patients with a higher percentage reduction in IOP (> 20.94%) had a lower risk of progression compared to those with less reduction. Inadequate IOP reduction, better baseline MD, presence of DH, and lower central corneal thickness were identified as risk factors for progression in advanced OAG patients.

Structural and vascular changes in glaucoma with single-hemifield defect: predictors of opposite hemifield visual field progression

PURPOSE

To investigate longitudinal changes in optic nerve head (ONH) superficial vessel density (VD), macular VD, circumpapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell-inner plexiform layer (GCIPL) thickness, and their associations with future VF defects in unaffected hemifields of primary open angle glaucoma (POAG) eyes with baseline VF defect confined to a single hemifield.

METHODS

This retrospective observational study included 61 POAG eyes with VF defect confined to a single hemifield monitored over a mean follow-up time of 2.7 years. Development of VF defect in opposite hemifield was defined based the Early Manifest Glaucoma Trail criteria. Each eye was classified into either "conversion" or "no conversion" groups according to development of VF defect in the unaffected hemifield. The rates of longitudinal changes in VD and structure parameters in each hemiretina were compared between the two groups. A Cox proportional hazard model was used to identify potential risk factors for VF conversion in the unaffected hemifield.

RESULTS

Among 61 eyes, 17 eyes (27.9%) were classified as "conversion" and 44 eyes (72.1%) were classified as "non-conversion" groups. The conversion group exhibited significantly greater rates of both VD and structural changes in both hemiretinas. In Cox proportional hazard model, greater rate of change in GCIPL thickness, ONH superficial VD, and macular VD of both hemiretinas and greater rate of change in RNFL thickness of the unaffected hemiretina were identified as risk factors for VF conversion in the unaffected hemifield.

CONCLUSIONS

Monitoring progressive changes in VD and structural parameters effectively predict future VF defect in the opposite hemifields of POAG eyes with single-hemifield defects.

Rates of Visual Field Change in Patients With Glaucoma and Healthy Individuals: Findings From a Median 25-Year Follow-up

Importance

Estimating the rate of glaucomatous visual field change provides practical assessment of disease progression and has implications for management decisions.

Objective

To assess the rates of visual field change in patients receiving treatment for glaucoma compared with healthy individuals over an extensive follow-up period and to quantify the impact of important covariates for these rates.

Design, Setting, and Participants

This prospective longitudinal cohort study was conducted in a hospital-based setting from January 1991 to February 2020. The study included 40 patients receiving treatment for open-angle glaucoma and 29 healthy participants. One eye of each participant was randomly selected as the study eye.

Exposures

Patients with glaucoma and healthy participants received testing with standard automated perimetry every 6 months. Individual rates of mean sensitivity change were computed using ordinary least-squares regression analysis, and linear mixed-effects modeling was used to estimate the mean rates of mean sensitivity change in the 2 groups and the impact of baseline mean sensitivity, baseline age, and follow-up intraocular pressure for rate estimates.

Main Outcomes and Measures

Rate of mean sensitivity change in patients with glaucoma and healthy participants.

Results

A total of 40 patients with glaucoma (median age, 53.07 years [IQR, 48.34-57.97 years]; 21 men [52%]) and 29 healthy participants (median age, 48.80 years [IQR, 40.40-59.07 years], 17 women [59%]) were followed up for a median of 25.65 years (IQR, 22.49-27.02 years) and 19.56 years (IQR, 16.19-26.21 years), respectively. Most participants (65 individuals [94%]) self-identified as White, with the exception of 2 patients with glaucoma (1 self-identified as Black and 1 as South Asian) and 2 healthy participants (both self-identified as South Asian). The mean follow-up intraocular pressure of patients with glaucoma (median, 15.83 mm Hg [IQR, 13.05-17.33 mm Hg]) was similar to that of healthy participants (median, 14.94 mm Hg [IQR, 13.28-16.01 mm Hg]; P = .25). In an ordinary least-squares regression analysis, 31 patients (78%) with glaucoma had rates of mean sensitivity change within the range of healthy participants (ie, between -0.20 dB/y and 0.15 dB/y). Linear mixed-effects modeling revealed that the mean (SE) rate of mean sensitivity change in healthy participants was 0.003 (0.033) dB/y (95% CI, -0.062 to 0.068; P = .93). In comparison, patients with glaucoma had a mean (SE) rate of mean sensitivity change that was -0.032 (0.052) dB/y faster, but this difference was not statistically significant (95% CI, -0.134 to 0.070; P = .53). Among covariates, only baseline mean sensitivity was associated with the rate of mean sensitivity change (mean [SE], 0.021 [0.010] dB/y/dB; 95% CI, 0.002-0.041; P = .03).

Conclusions and Relevance

The results of this cohort study suggest that over a median follow-up of more than 25 years, the rate of visual field change in patients receiving treatment for glaucoma was comparable to that of healthy individuals. These findings could guide practitioners in making management decisions.

Primary trabeculectomy versus primary glaucoma eye drops for newly diagnosed advanced glaucoma: TAGS RCT

BACKGROUND

Patients diagnosed with advanced primary open-angle glaucoma are at a high risk of lifetime blindness. Uncertainty exists about whether primary medical management (glaucoma eye drops) or primary surgical treatment (augmented trabeculectomy) provide the best and safest patient outcomes.

OBJECTIVES

To compare primary medical management with primary surgical treatment (augmented trabeculectomy) in patients with primary open-angle glaucoma presenting with advanced disease in terms of health-related quality of life, clinical effectiveness, safety and cost-effectiveness.

DESIGN

This was a two-arm, parallel, multicentre, pragmatic randomised controlled trial.

SETTING

Secondary care eye services.

PARTICIPANTS

Adult patients presenting with advanced primary open-angle glaucoma in at least one eye, as defined by the Hodapp-Parrish-Anderson classification of severe glaucoma.

INTERVENTION

Primary medical treatment - escalating medical management with glaucoma eye drops. Primary trabeculectomy treatment - trabeculectomy augmented with mitomycin C.

MAIN OUTCOME MEASURES

The primary outcome was health-related quality of life measured with the Visual Function Questionnaire-25 at 2 years post randomisation. Secondary outcomes were mean intraocular pressure; EQ-5D-5L; Health Utilities Index 3; Glaucoma Utility Index; cost and cost-effectiveness; generic, vision-specific and disease-specific health-related quality of life; clinical effectiveness; and safety.

RESULTS

A total of 453 participants were recruited. The mean age of the participants was 67 years (standard deviation 12 years) in the trabeculectomy arm and 68 years (standard deviation 12 years) in the medical management arm. Over 65% of participants were male and more than 80% were white. At 24 months, the mean difference in Visual Function Questionnaire-25 score was 1.06 (95% confidence interval -1.32 to 3.43; p = 0.383). There was no evidence of a difference between arms in the EQ-5D-5L score, the Health Utilities Index or the Glaucoma Utility Index. At 24 months, the mean intraocular pressure was 12.40 mmHg in the trabeculectomy arm and 15.07 mmHg in the medical management arm (mean difference -2.75 mmHg, 95% confidence interval -3.84 to -1.66 mmHg; p < 0.001). Fewer types of glaucoma eye drops were required in the trabeculectomy arm. LogMAR visual acuity was slightly better in the medical management arm (mean difference 0.07, 95% confidence interval 0.02 to 0.11; p = 0.006) than in the trabeculectomy arm. There was no evidence of difference in safety between the two arms. A discrete choice experiment updated the utility values for the Glaucoma Utility Index. The within-trial economic analysis found a small increase in the mean EQ-5D-5L score (0.04) and that trabeculectomy has a higher probability of being cost-effective than medical management. The incremental cost of trabeculectomy per quality-adjusted life-year was £45,456. Therefore, at 2 years, surgery is unlikely to be considered cost-effective at a threshold of £20,000 per quality-adjusted life-year. When extrapolated over a patient's lifetime in a model-based analysis, trabeculectomy, compared with medical treatment, was associated with higher costs (average £2687), a larger number of quality-adjusted life-years (average 0.28) and higher incremental cost per quality-adjusted life-year gained (average £9679). The likelihood of trabeculectomy being cost-effective at a willingness-to-pay threshold of £20,000 per quality-adjusted life year gained was 73%.

CONCLUSIONS

Our results suggested that there was no difference between treatment arms in health-related quality of life, as measured with the Visual Function Questionnaire-25 at 24 months. Intraocular pressure was better controlled in the trabeculectomy arm, and this may reduce visual field progression. Modelling over the patient's lifetime suggests that trabeculectomy may be cost-effective over the range of values of society's willingness to pay for a quality-adjusted life-year.

FUTURE WORK

Further follow-up of participants will allow us to estimate the long-term differences of disease progression, patient experience and cost-effectiveness.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN56878850.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 72. See the NIHR Journals Library website for further project information.

Detecting Progression of Retinitis Pigmentosa Using the Binomial Pointwise Linear Regression Method

Purpose

A method of evaluating central visual field (VF) progression in eyes with retinitis pigmentosa (RP) has still to be established. We previously reported the potential merit of applying a binomial test to pointwise linear regression (binomial PLR) in glaucoma progression. In the current study, we investigated the usefulness of binomial PLR in eyes with RP.

Methods

A series of 10 VFs (VF 1–10, Humphrey field analyzer, 10-2 test) from 196 eyes of 103 patients with RP were collected retrospectively. The PLR was performed by regressing the total deviation of all test points with the complete series of 10 VFs. The accuracy (positive predictive value, negative predictive value, and false-positive rate) and the time required to detect VF progression with shorter VF series (from VF 1–5 to VF 1–9) were compared across the binomial PLR, a permutation analysis of PLR (PoPLR), and a mean deviation (MD) trend analysis.

Results

In evaluating VF progression, the binomial PLR was comparable with the PoPLR and MD trend analyses in its positive predictive value (0.55 to 0.95), negative predictive value (0.67 to 0.92), and false-positive rate (0.01 to 0.05). The binomial PLR required significantly less time to detect VF progression (5.0 ± 2.0 years) than the PoPLR and MD trend analyses (P < 0.01, P < 0.001, respectively).

Conclusions

The application of a binomial PLR achieved reliable and earlier detection of central VF progression in eyes with RP.

Translational Relevance

A binomial PLR was useful in assessing VF progression in RP.

The Association Between Intraocular Pressure and Visual Field Worsening in Treated Glaucoma Patients

PRECIS

In treated eyes with mild/suspect glaucoma, intraocular pressure (IOP) increments are associated with worsening mean deviation (MD) once IOP reaches the 20s. In moderate/advanced eyes, IOP increments are associated with worse visual field (VF) performance across the entire IOP range.

PURPOSE

The purpose of this study was to describe the relationship between mean treated IOP and VF worsening and understand how this relationship is affected by glaucoma severity and IOP range.

METHODS

A total of 1446 eyes of 869 treated glaucoma patients with at least 5 longitudinal reliable VF tests and IOP measures were included. Mixed-effects linear models were employed to understand the effect of eye-specific mean treated IOP on MD slope. Models included interaction terms to assess the differing relationships between MD slope and mean IOP by glaucoma severity (suspect/mild vs. moderate/advanced) and splines to account for the differing effects of mean IOP on MD slope at different IOP ranges (above or below 21 mm Hg).

RESULTS

In suspect/mild glaucoma, when treated IOP values were <21 mm Hg, a 1 mm Hg increment in IOP was not associated with an increase in the rate of VF worsening (P>0.05) but when treated IOP values rose >21 mm Hg, a 1 mm Hg increment in IOP was associated with faster VF worsening (-0.09 dB/y per 1 mm Hg increment, P<0.05). In moderate/advanced disease, a 1 mm Hg increment in treated IOP was associated with faster VF worsening both below and above 21 mm Hg, but the effect was much more pronounced in the higher range (-0.02 dB/y per mm Hg increment <21 mm Hg vs. -0.74 dB/y per mm Hg increment >21 mm Hg, P<0.05 for both).

CONCLUSION

IOP remained associated with VF worsening in eyes with more advanced glaucoma throughout the IOP range but was only associated with VF worsening in eyes with less severe glaucoma at higher IOP.

Achieving low target intraocular pressures in severe glaucoma

PURPOSE

This study aimed to assess details of therapy required to achieve an intraocular pressure (IOP) of ⩽12 mmHg in patients with severe glaucoma of different etiologies.

METHODS

Patients with a follow-up of at least 1 year, who fulfilled inclusion criteria were selected, and data analyzed with respect to baseline IOP, number of medications, and/or surgeries required to achieve an IOP of ⩽12 mmHg and ⩾6 mmHg. Final IOP, visual field status and medications/surgery required were noted.

RESULTS

About 127 eyes of 85 patients met all criteria. There were 48 eyes having primary angle closure glaucoma (PACG), 16 eyes with primary open angle glaucoma (POAG), 17 eyes of juvenile open angle glaucoma (JOAG), and 46 eyes of secondary glaucoma. The mean baseline IOP was 33.14 ± 11.07 mmHg and final IOP 10.25 ± 1.81 mmHg. In the age group >40 years, 29.63% of patients were controlled on medication as compared to 9.09% and 5.71% in the age group of <20 years and 20-40 years (p = 0.007). With a baseline IOP of <25 mmHg, 48.65% required a trabeculectomy, whereas for 25-30, and >30 mmHg, 62.5% and 97.29% respectively, required surgery (p < 0.001).66.67% of patients having mean deviation of -12 to -16 dB (decibels) on Humphrey field analyzer (HFA) underwent surgery to achieve target IOP in comparison to 83.52% who had mean deviation greater than -16 dB (p = 0.036).

CONCLUSION

Only 21.26% of severe glaucoma eyes could be controlled on medications alone. A baseline IOP of >25 mmHg, age <40 years and mean deviation worse than -16 dB, had a higher frequency of trabeculectomies to achieve an IOP of ⩽12 mmHg.

Pointwise Methods to Measure Long-term Visual Field Progression in Glaucoma

Importance

Rates of visual field (VF) progression vary among patients with glaucoma. Knowing the rate of progression of individual patients would allow appropriately aggressive therapy for patients with high rates of visual loss and protect those with low rates from unnecessary therapy.

Objective

To compare 3 pointwise methods of estimating the rate of VF progression in glaucoma.

Design, Setting, and Participants

This retrospective, observational cohort study included 729 eyes of 567 consecutive patients with primary open-angle glaucoma who had at least 6 reliable VFs and at least 3 years of follow-up. One hundred seventy-six patients (257 eyes) were treated at a tertiary glaucoma center; in addition, data were collected from 391 participants (472 eyes) in the Advanced Glaucoma Intervention Study. Data were collected from May 1988 to November 2004 and analyzed from October 2018 to February 2019.

Exposures

Estimates of VF progression were measured with guided progression analysis (GPA), pointwise linear regression (PLR), and the glaucoma rate index (GRI). A subgroup analysis was performed in a subset of patients with likely VF progression and likely VF stability.

Main Outcomes and Measures

Proportion of VF series detected as progressing, estimates of false-positive proportions, time to detect progression, and agreement among measures.

Results

Among the 567 patients included in the analysis, mean (SD) age was 65.6 (9.7) years, 300 (52.9%) were female, and 295 (52.0%) were white. The median baseline mean deviation was -6.7 (interquartile range [IQR], -11.6 to -3.5) dB; the median follow-up time, 8.9 (IQR, 7.3-10.4) years. The proportion of eyes labeled as progressing was 27.7% according to the GPA, 33.5% according to the PLR, and 52.9% according to the GRI; pairwise differences for GRI vs PLR were 20% (95% CI, 17%-23%); for GRI vs GPA, 25% (95% CI, 22%-29%); and for PLR vs GPA, 6% (95% CI, 3%-9%; P < .001 for all comparisons, McNemar test). The shortest median time to progression was with the GRI (8.8 [IQR, 2.4-10.5 years), compared with the GPA and PLR (both >16 years). The hazard ratio of VF progression for GRI vs PLR (reference) was 11.3 (95% CI, 9.2-13.7); for GRI vs GPA (reference), 18.1 (95% CI, 14.5-22.6); and for PLR vs GPA (reference), 1.5 (95% CI, 1.3-1.9; P < .001 for all comparisons, Cox proportional hazards regression). These results held in the subgroup with likely progression; the proportions of progressing eyes were 73.7% (115 of 156) for GPA, 81.4% (127 of 156) for PLR, and 92.9% (145 of 156) for GRI. Pairwise difference for GRI vs PLR was 11.5% (95% CI, 7.4%-17.6%; P < .001, McNemar test); for GRI vs GPA, 19.2% (95% CI, 12.6%-26.4%; P < .001, McNemar test); and for PLR vs GPA, 7.7% (95% CI, 0.3%-15.7%; P = .08, McNemar test).

Conclusions and Relevance

These results suggest GRI can detect long-term VF progression in glaucoma earlier than PLR or GPA. Validation with prospective designs may strengthen the generalizability and value of this method.

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.

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.

Visual Field Prediction using Recurrent Neural Network

Artificial intelligence capabilities have, recently, greatly improved. In the past few years, one of the deep learning algorithms, the recurrent neural network (RNN), has shown an outstanding ability in sequence labeling and prediction tasks for sequential data. We built a reliable visual field prediction algorithm using RNN and evaluated its performance in comparison with the conventional pointwise ordinary linear regression (OLR) method. A total of 1,408 eyes were used as a training dataset and another dataset, comprising 281 eyes, was used as a test dataset. Five consecutive visual field tests were provided to the constructed RNN as input and a 6^th visual field test was compared with the output of the RNN. The performance of the RNN was compared with that of OLR by predicting the 6^th visual field in the test dataset. The overall prediction performance of RNN was significantly better than OLR. The pointwise prediction error of the RNN was significantly smaller than that of the OLR in most areas known to be vulnerable to glaucomatous damage. The RNN was also more robust and reliable regarding worsening in the visual field examination. In clinical practice, the RNN model can therefore assist in decision-making for further treatment of glaucoma.

Evaluating the efficacy of short duration Mitomycin C in safe surgery system trabeculectomy combined with cataract surgery

Purpose: To compare the efficacy of 0.2 mg/ml Mitomycin C (MMC) applied for 1-minute versus 2-minutes in patients undergoing combined surgery for primary glaucoma coexistent with cataract. Materials and methods: This was a randomized controlled clinical trial of 63 patients operated on for primary glaucoma (POAG or PACG) with visually significant cataract. All patients underwent safe surgery system trabeculectomy with manual small incision cataract surgery (MSIC) and implantation of PC IOL. Patients were randomized into intra-operative MMC 0.2 mg/ml for 1-minute (study group) and MMC 0.2 mg/ml for 2-minutes (control group). Success was measured on the basis of two different intraocular pressure (IOP) goals (IOP ≤21 mmHg, IOP ≤18 mmHg) and mean IOP reduction from baseline at the end of 12 months. Results: At 12 months, significant decreases in mean IOP were observed in both groups (P<0.001).The mean IOP reduction was 31.33±9.06% in the study group, as compared to 43.32±9.38% in the control group (P<0.001). The overall success for IOP ≤21 mm Hg was 80.5% in the study group and 90.9% in the control group (P<0.05). Kaplan-Meier analysis showed an insignificant difference in overall success rates of the two groups. Conclusion: The IOP reduction with 2-minute MMC (0.2 mg/ml) is more effective than 1-minute MMC after 12 months. It offers a decrease in anti-glaucoma medications and substantial visual recovery in combined surgery done for primary glaucoma coexistent with cataract.

Early Detection of Glaucomatous Visual Field Progression Using Pointwise Linear Regression With Binomial Test in the Central 10 Degrees

PURPOSE

We previously reported that it was beneficial to apply binomial pointwise linear regression (PLR) to detect 24-2 glaucomatous visual field (VF) progression, compared to mean deviation (MD) trend analysis and permutation analysis of PLR (PoPLR). The purpose of the current study was to validate the usefulness of the binomial PLR method to detect VF progression in the central 10 degrees in glaucoma patients.

DESIGN

Reliability assessment.

METHODS

A series of 15 VFs (Humphrey Field Analyzer 10-2 SITA-standard) from 97 eyes in 69 primary open-angle glaucoma patients, obtained over 8.5 ± 1.3 years (mean ± SD), were investigated. PLR was performed by regressing the total deviation of all test points on the series of 15 VFs. VF progression was determined from the analyses of VF test points using the binomial test (1-sided, P < .025). The time needed to detect VF progression was also investigated. The results were compared with PoPLR and MD trend analyses.

RESULTS

The binomial PLR was comparable to PoPLR and MD trend analyses in the positive predictive value (0.19 to 0.80), the negative predictive value (0.86 to 1.0), and the false positive rate (0.0 to 0.13) to evaluate glaucomatous VF progression. The time needed to detect VF progression (4.2 ± 1.8 years) was significantly shorter with the binomial PLR method compared with PoPLR and MD trend analysis (P = .04, P = .012, respectively).

CONCLUSIONS

The binomial PLR method detected glaucomatous VF progression in the central 10 degrees significantly earlier than PoPLR and MD trend analyses.

Effect of quantitative intraocular pressure reduction on visual field defect progression in normal tension glaucoma under medical therapy applying Markov model

Purpose

To quantitatively evaluate the association of intraocular pressure (IOP) reduction with visual field defect (VFD) progression in normal tension glaucoma (NTG) under medical therapy.

Patients and methods

Clinical data for 622 eyes of 311 primary open-angle glaucoma and NTG patients were collected from April 2006 to March 2016. Of these patients, those with normal IOP, glaucomatous VFD by Anderson’s criteria, corrected visual acuity ≥0.7, >5 years of medical therapy, ≥5 visual field tests at least five times at 12-month intervals, visual field testing reliability coefficients of ≤33%, and mean deviation (MD) exceeding below −20 dB in the initial visual field test were included in this retrospective data analysis. MD and IOP data were collected at baseline and after 5 years. Following MD categorization into stages I to IV, stage transition matrices were generated using a Markov model to evaluate VFD changes. Eyes were divided based on IOP reduction (0%, 10%, 15%, 20%, 25%, 30%) from baseline. VFD aggravations were compared using the Markov model and MD slopes with IOP reduction rates as cutoff values.

Results

Overall, 132 eyes of 132 NTG patients fulfilled the eligibility criteria. MD decreased significantly (P<0.0001) at 5 years vs baseline. During follow-up, visual field stage using the Markov model was constant in ~60%, with transitions in ~40%. IOP decreased significantly (P>0.001) at 5 years vs baseline. Though MD slopes did not differ significantly between each of the groups that achieved the various IOP reduction cut-off values and the corresponding group that did not achieve the cut-off values, a significant difference (P=0.0432) in VFD was found between the group that achieved the 25% cut-off value and the group that did not when evaluated using the Markov model.

Conclusion

In NTG patients, VFD aggravation was significantly suppressed in groups with IOP reductions of ≥25% from baseline.

Detection and measurement of clinically meaningful visual field progression in clinical trials for glaucoma

Glaucomatous visual field progression has both personal and societal costs and therefore has a serious impact on quality of life. At the present time, intraocular pressure (IOP) is considered to be the most important modifiable risk factor for glaucoma onset and progression. Reduction of IOP has been repeatedly demonstrated to be an effective intervention across the spectrum of glaucoma, regardless of subtype or disease stage. In the setting of approval of IOP-lowering therapies, it is expected that effects on IOP will translate into benefits in long-term patient-reported outcomes. Nonetheless, the effect of these medications on IOP and their associated risks can be consistently and objectively measured. This helps to explain why regulatory approval of new therapies in glaucoma has historically used IOP as the outcome variable. Although all approved treatments for glaucoma involve IOP reduction, patients frequently continue to progress despite treatment. It would therefore be beneficial to develop treatments that preserve visual function through mechanisms other than lowering IOP. The United States Food and Drug Administration (FDA) has stated that they will accept a clinically meaningful definition of visual field progression using Glaucoma Change Probability criteria. Nonetheless, these criteria do not take into account the time (and hence, the speed) needed to reach significant change. In this paper we provide an analysis based on the existing literature to support the hypothesis that decreasing the rate of visual field progression by 30% in a trial lasting 12-18 months is clinically meaningful. We demonstrate that a 30% decrease in rate of visual field progression can be reliably projected to have a significant effect on health-related quality of life, as defined by validated instruments designed to measure that endpoint.

Evaluating the accuracy of the visual field index for the Humphrey Visual Field Analyzer in patients with mild to moderate glaucoma

PURPOSE

To evaluate the accuracy of the visual field index (VFI) for the Humphrey Visual Field Analyzer in a population of patients with mild to moderate glaucoma.

DESIGN

Retrospective cohort study.

METHODS

The study included 42 patients (61 eyes) with at least 11 years of follow-up, and annual automated visual fields (VFs). Patients with mean deviations ≤-20 dB were excluded. All unreliable fields were omitted (fixation losses ≥20%, false-positive ≥15%, false-negative ≥33%). The VFs were divided into two 5-year series and the data were analyzed by the new Humphrey Visual Field Analyzer software. Projected VFIs from the first 5 years were compared with observed values obtained from the last 5 years. Unreliable fields initially excluded were reintroduced into the series (22 eyes) to create a comparison.

RESULTS

Predicted VFIs were accurate with a mean overestimation of VF deterioration of 1.37% (95% CI: -0.22%, 2.96%). Of the predicted values, 95% were between -4.5% and 5.2% of the observed values when the predicted VFI was ≥90%; and between -13.8% and 20.5% when the predicted VFI was <90%. No statistical difference was found between the reliable and unreliable series (mean difference of 0.09% [95% CI: -0.41%, 0.59%]).

CONCLUSION

The new software for the Humphrey Visual Field Analyzer projects an accurate value for patients when the predicted VFI is ≥90%. Clinicians should consider the limitations of the software, especially for those patients with greater initial VF loss.

[Practical aspects of glaucoma perimetry]

Automatic static white-on-white perimetry is state of the art for the visual field examination of glaucoma patients. Full threshold measurements require at least 5 min. Careful instruction and supervision of the patient help to achieve high quality results. Alternative methods, such as the various types of flicker perimetry have a higher sensitivity and complement the early diagnosis. Attention must be paid to the specificity of these methods. Diagnosis may be difficult because the first changes do not have a typical topography. The typical examination interval for follow-up is 1 year but should be shorter in the beginning and in cases with deterioration. The evaluation of visual field development is highly important for glaucoma therapy control. Modern analysis programs offer excellent tools for this purpose. Some programs automatically detect learning effects and unreliable examinations. The change in global indices, e.g. median defect depth (MD), functional defect (FD) and visual field index (VFI) is plotted and statistically analyzed. Local trends are shown in symbol maps. Some programs calculate a prognosis of the future development of the visual field.

Detection of progression of glaucomatous visual field damage using the point-wise method with the binomial test

Purpose

To compare the performance of newly proposed point-wise linear regression (PLR) with the binomial test (binomial PLR) against mean deviation (MD) trend analysis and permutation analyses of PLR (PoPLR), in detecting global visual field (VF) progression in glaucoma.

Methods

15 VFs (Humphrey Field Analyzer, SITA standard, 24-2) were collected from 96 eyes of 59 open angle glaucoma patients (6.0 ± 1.5 [mean ± standard deviation] years). Using the total deviation of each point on the 2^nd to 16^th VFs (VF2-16), linear regression analysis was carried out. The numbers of VF test points with a significant trend at various probability levels (p<0.025, 0.05, 0.075 and 0.1) were investigated with the binomial test (one-side). A VF series was defined as “significant” if the median p-value from the binomial test was <0.025. Similarly, the progression analysis was carried out using only second to sixth VFs (VF2-6). The performance of each method was evaluated using the ‘consistency measures’; proportion both significant (PBS): both VF series (VF2-6 and VF2-16) were “significant”, proportion both were not significant (PBNS): both were “not significant”, proportion inconsistently significant (PIS): VF2-16 was “not significant” but VF2-6 was “significant”. A similar analysis was carried out using VF2-7 and VF2-15 series, and the performance was compared with MD trend analysis and PoPLR.

Results

The PBS of the binomial PLR method (0.14 to 0.86) was significantly higher than MD trend analysis (0.04 to 0.89) and PoPLR (0.09 to 0.93). The PIS of the proposed method (0.0 to 0.17) was significantly lower than the MD approach (0.0 to 0.67) and PoPLR (0.07 to 0.33). The PBNS of the three approaches were not significantly different.

Conclusions

The binomial BLR method gives more consistent results than MD trend analysis and PoPLR, hence it will be helpful as a tool to ‘flag’ possible VF deterioration.

Socioeconomic status as a risk factor for late presentation of glaucoma in Canada

OBJECTIVE

To evaluate the effect of socioeconomic status on late presentation of glaucoma.

DESIGN

Prospective, multicentre, cross-sectional study.

PARTICIPANTS

Newly diagnosed open-angle glaucoma.

METHODS

Eligible subjects with newly diagnosed open-angle glaucoma underwent a comprehensive ocular examination and were classified as mild, moderate, or advanced according to the Canadian Ophthalmological Society glaucoma guidelines. Socioeconomic status was estimated by linking the subjects' postal code to the median household income in the 2006 Canadian population census at the level of dissemination areas. Five equal income groups ranging from the lowest to the highest income quintile were considered and compared regarding the frequency and proportion of moderate or advanced glaucoma.

RESULTS

A total of 290 subjects were included in the analysis; 151 (52.1%) had mild, 79 (26.9%) moderate, and 60 (21.0%) advanced disease at initial diagnosis. Patients with newly diagnosed glaucoma were less likely to come from the poorest neighborhood areas (16.21%) when compared with an expected one fifth (20%) of patients presented in each of the 5 social economic groups (P = 0.56). Compared with people from the poorest neighborhood areas, people from the richest neighborhood areas had a marginally lower risk for having moderate or advanced glaucoma at first presentation (prevalence ratio 0.66, 95% confidence interval: 0.43-1.02, P = 0.06). This association was stronger among those ≥65 years old (P = 0.006).

CONCLUSIONS

To the best of our knowledge, this is the first study in Canada to provide evidence that socioeconomic deprivation is associated with greater severity of glaucoma at presentation, specifically for those ≥65 years old. Consideration should be given to targeting poor neighborhood areas for glaucoma education, screening, or both.

De-insurance in Ontario has reduced use of eye care services by the socially disadvantaged

OBJECTIVE

Effective November 1, 2004, the Ontario Ministry of Health and Long-Term Care de-insured, or delisted, routine eye examinations for Ontarians aged 20 to 64 years. We examined whether this delisting reduced Ontarians' access to eye care providers (ophthalmologists and optometrists).

DESIGN

Cross-sectional survey.

PARTICIPANTS

Ontario respondents to the Canadian Community Health Survey in 2000/2001 (n = 39 234 before delisting) and 2007/2008 (n = 43 835 after delisting).

METHODS

We compared utilization rates of eye care providers by Ontarians in a 12-month period in 2000/2001 to utilization rates in 2007/2008 using self-reported data.

RESULTS

Among Ontarians aged 40 to 64 years, utilization was significantly reduced (-7.2%, p < 0.05) after delisting by those who did not have a secondary school graduation certificate. This was compared to a slight reduction (-0.7%, p > 0.05) by those who had completed secondary school or higher education. A reduction of -5.4% was observed among Ontarians in the lowest income quintile in contrast to increased utilization in all other income groups (p > 0.05). Before delisting, the gap in utilization between people with and without a secondary school graduation certificate was 4.7%. This gap doubled to 11.2% after delisting (p < 0.05). The disparity in utilization between those in the highest and lowest income quintile was 4.5% before delisting and 12.0% after delisting (p > 0.05). Cost was the likely barrier that resulted in this finding.

CONCLUSIONS

The use of eye care providers among socially disadvantaged Ontarians decreased significantly after vision care services were delisted. The effects of delisting appear to have caused an inequity in access to eye care providers, and that contradicts the objectives of the Canada Health Act.

The long-term outcomes of four alternative treatment strategies for primary open-angle glaucoma

PURPOSE

To evaluate the long-term effects and costs of four treatment strategies for primary open-angle glaucoma compared to usual care.

METHODS

Cost-effectiveness analyses with a lifelong horizon were made from a societal perspective. Data were generated with a patient-level model based on discrete event simulation. The model structure and parameter estimates were based on literature, particularly clinical studies on the natural course of glaucoma and the effect of treatment. We simulated heterogeneous cohorts of 3000 patients and explored the impact of uncertainty with sensitivity analyses.

RESULTS

The incremental cost-effectiveness ratio (ICER) of initial treatment with a prostaglandin analogue compared with a β-blocker was €12.931 per quality-adjusted life year (QALY) gained. A low initial target pressure (15 mmHg) resulted in 0.115 QALYs gained and €1550 saved compared to a gradual decrease from 21 to 15 mmHg upon progression. Visual field (VF) measurements every 6 rather than 12 months lead to health gains at increased costs (ICER €173,486 per QALY gained), whereas measurements every 24 months lead to health losses at reduced costs (ICER €21,516 per QALY lost). All treatment strategies were dominant over 'withholding treatment'.

CONCLUSIONS

From a cost-effectiveness point of view, it seems advantageous to aim for a low intraocular pressure in all glaucoma patients. The feasibility of this strategy should therefore be investigated. Additionally, the cost-effectiveness outcomes of initiating monotherapy with a prostaglandin analogue and reducing the frequency of VF testing may be acceptable.

Attitudes of consultant ophthalmologists in the UK to initial management of glaucoma patients presenting with severe visual field loss: a national survey

BACKGROUND

Recent National Institute of Clinical Excellence guidance suggests primary surgery should be offered to patients presenting with glaucoma with severe visual field loss. We undertook a survey of UK consultant ophthalmologists to determine if this represents current practice and explore attitudes towards managing patients with advanced glaucoma at presentation.

DESIGN

Questionnaire evaluation study.

PARTICIPANTS

All consultant ophthalmologists currently practicing in the UK.

METHODS

A single-page questionnaire was posted to all consultants (n = 910) currently practicing in the UK along with a pre-paid return envelope. A second questionnaire was sent to non-responders (n = 459).

MAIN OUTCOME MEASURES

Questionnaire responses.

RESULTS

626 responses were received representing 68.8% of the population surveyed. 152 (24%) volunteered a specialist interest in glaucoma. Consensus opinion for both glaucoma specialists (64.9%) and non-glaucoma specialists (62.4%) was to start with primary medical therapy, most commonly citing surgical risk as the primary reason (23% and 22%, respectively) for this approach. Most felt the highest intraocular pressure measurement during follow up (measured in clinic) was the most important variable for prevention of further visual loss (60% of glaucoma specialists and 55% of non-glaucoma specialists). Eighty-three per cent of all responders suggested they would change their practice if evidence supporting primary surgery as a safe and more effective approach existed.

CONCLUSIONS

Recent National Institute of Clinical Excellence guidance does not reflect the current management approach of UK ophthalmologists. The primary concern was related to potential complications of surgery although most practitioners would be willing to change their practice if evidence existed supporting primary surgery in patients presenting with advanced glaucoma.

Incorporating life expectancy in glaucoma care

AIM

To calculate for which combinations of age and perimetric disease stage glaucoma patients are unlikely to become visually impaired during their lifetime.

METHODS

We used residual life expectancy data (life expectancy adjusted for the age already reached) as provided by Statistics Netherlands and rates of progression as derived from published studies. We calculated the baseline mean deviation (MD) for which an individual would reach a MD of -20 dB at the end of life as a function of age and rate of progression. For situations in which the individual rate of progression is unknown, we used the 90th percentiles of rate of progression and residual life expectancy. For situations in which the individual rate of progression is known, we used the 95th percentile of the residual life expectancy.

RESULTS

An easily applicable graphical tool was developed that enables an accurate estimate of the probability of becoming visually impaired during lifetime, given age, current glaucomatous damage, and--if available--the individual rate of progression.

CONCLUSIONS

This novel tool enables the clinician to incorporate life expectancy in glaucoma care in a well-founded manner and may serve as a starting point for personalized decision making.

The willingness of patients presenting with advanced glaucoma to participate in a trial comparing primary medical vs primary surgical treatment

AIM

The aim of this study is to examine the attitudes of patients, who presented with advanced glaucoma in at least one eye, to participation in a randomised prospective trial comparing primary medical treatment with primary surgical treatment for advanced glaucoma.

METHODS

Patients who had presented with advanced glaucoma (>15 dB loss mean deviation on Humphrey visual field testing) in at least one eye were asked to participate. Five focus groups comprising of 4-8 patients and consisting of 29 patients in total were undertaken. The group interviews were conducted by two experienced qualitative researchers, an ophthalmic clinician was present to clarify technical issues. The focus group discussions were taped and transcribed in full, and analysed through a process of familiarisation, open (inductive) coding, theme generation, theme refinement, and thematic mapping.

RESULTS

Three overarching themes were identified: (1) the extent of patients' knowledge, (2) anxieties about surgery, and (3) concerns about compromised care due to trial involvement; these themes were further classified into eight sub-themes.

CONCLUSIONS

Patients' willingness to participate in randomised clinical studies is significantly connected to their level of comprehension and insight about the medical condition, its treatment, and the research process; misunderstandings about any of these aspects may act as a significant barrier to trial recruitment. Recruitment rates for future randomised trials may be enhanced by ensuring that patients have full and accurate information about the treatment alternatives, and that uncertainty exists for best patient outcomes between treatment options, and reassuring potential participants that the research process, in particular randomisation, will not compromise clinical care.

Comparison of the effects of dorzolamide/timolol and latanoprost/timolol fixed combinations upon intraocular pressure and progression of visual field damage in primary open-angle glaucoma

OBJECTIVE

To report the long-term effect of the dorzolamide/timolol (DTFC) and latanoprost/timolol (LTFC) fixed combinations on intraocular pressure (IOP) and visual field defects over time in naïve primary open-angle glaucoma (POAG) patients.

STUDY DESIGN AND METHODS

Prospective, 4-year, open-label, interventional study.

SETTING

high-volume outpatient clinic.

PATIENTS

178 patients were assigned to receive medical treatment with either DTFC or LTFC.

INTERVENTION

over 4 years, tri-monthly IOP and yearly visual field assessment (Octopus 101, Program G2). outcomes: effect of treatment on IOP, visual field indices mean defect (MD), and visual field indices variance loss (VL) over time.

RESULTS

DTFC and LTFC significantly (p < or = 0.001) reduced mean IOP over time (from 22.6 +/- 3.0 to 13.8 +/- 1.9 mmHg and from 22.3 +/- 4.0 to 14.7 +/- 1.9 mmHg, respectively). In all, 56 patients (70.9%) and 14 (17.9%) showed a significant MD improvement in the DTFC- and LTFC-treated groups, respectively, p = 0.0001. DTFC progressively and significantly decreased mean VL (from 30.21 +/- 23.88 to 8.11 +/- 8.50 dB). Mean sensitivity slopes during follow-up were 1.14 dB/year and -0.34 dB/year for DTFC and LTFC treatment groups, respectively; p = 0.028.

CONCLUSION

Both treatments significantly reduced IOP as compared with baseline. Additionally, treatment with dorzolamide/timolol fixed combination seem to be effective in preventing glaucomatous visual field progression. This study has some limitations that should be noted, among them its open-label design.

[Analysis of a new visual field index, the VFI, in Ocular Hypertension and Glaucoma]

OBJECTIVE

The Visual Field Index -VFI- is a new perimetric index allowing evaluation of visual function level and progression. In this study, we analysed this new index, that provides a trend analysis of visual field loss progression in Ocular Hypertension and Glaucoma. We also compared results with event analysis.

METHODS

Retrospective study on 94 eyes of 54 patients: 35 OHT(ocular hypertension), 34 early POAG (primary open angle glaucoma) (0>MD>-6 dB), 13 moderate POAG (-6>MD>-12 dB) and 12 advanced POAG (MD<-12 dB), with a mean follow-up of 6.5 years (4 to 8 years). Each subject performed a mean number of 10 standard automated perimetry visual field tests (Humphrey SITA Standard 24-2), excluding tests without reliable indices. VFI progression rate was analysed. VFI progression during the first half period of follow up was compared with that during the second half period. VFI progression was confronted with script alert messages delivered by the last GPA (Guided Progression Analysis) event analysis program.

RESULTS

VFI values were "stable or with low progression" in 100% of OHT patients, 88% of early POAG, 38.5% of moderate POAG, 33% of advanced POAG. Progression during the first half period (mean of 3 years) of follow-up could be extrapolated for the second half period in 97% of OHT patients, 76% of early POAG, 70% of moderate POAG, 75% of advanced POAG. Results from VFI trend analysis and GPA event analysis corresponded in 97% of OHT patients, 85% of early POAG, 85% of moderate POAG, and 87% of advanced POAG.

DISCUSSION

VFI seems to be a useful indicator for glaucoma evaluation and progression follow-up. It completes the event analysis. Some very advanced POAG cannot be analysed by GPA event analysis. VFI should be able to be used for further follow-up. All these results require validation in larger population. The purpose would be to assess if VFI is able to detect different profiles of progression to help treatment decisions.

Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements

Purpose

The goal of this work was to (i) determine patterns of progression in glaucomatous visual field loss, (ii) compare the detection rate of progression between locally condensed stimulus arrangements and conventional 6° × 6° grid, and (iii) assess the individual frequency distribution of test locations exhibiting a local event (i.e., an abrupt local deterioration of differential luminance sensitivity (DLS) by more than -10dB between any two examinations).

Methods

The visual function of 41 glaucomatous eyes of 41 patients (16 females, 25 males, 37 to 75 years old) was examined with automated static perimetry (Tuebingen Computer Campimeter or Octopus 101-Perimeter). Stimuli were added to locally enhance the spatial resolution in suspicious regions of the visual field. The minimum follow-up was four subsequent sessions with a minimum of 2-month (median 6-month) intervals between each session. Progression was identified using a modified pointwise linear regression (PLR) method and a modified Katz criterion. The presence of events was assessed in all progressive visual fields.

Results

Eleven eyes (27%) showed progression over the study period (median 2.5 years, range 1.3–8.6 years). Six (55%) of these had combined progression in depth and size and five eyes (45%) progressed in depth only. Progression in size conformed always to the nerve fiber course. Seven out of 11 (64%) of the progressive scotomata detected by spatially condensed grids would have been missed by the conventional 6° × 6° grid. At least one event occurred in 64% of all progressive eyes. Five of 11 (46%) progressive eyes showed a cluster of events.

Conclusions

The most common pattern of progression in glaucomatous visual fields is combined progression in depth and size of an existing scotoma. Applying individually condensed test grids remarkably enhances the detection rate of glaucomatous visual field deterioration (at the expense of an increased examination time) compared to conventional stimulus arrangements.

A visual field index for calculation of glaucoma rate of progression

PURPOSE

To present a new perimetric index for calculating the rate of glaucomatous progression and to compare its performance with the traditional mean deviation index (MDI).

DESIGN

Experimental study describing a device and retrospective cohort study.

METHODS

We developed a new visual field index, the glaucoma progression index (GPI), intended to be less affected by cataract than the MDI by calculating age-corrected defect depth at test points identified as significantly depressed in pattern deviation probability maps. The valid operating range for pattern deviation analysis was estimated. When exceeding this range, the total deviation probability maps were used for identification of significantly depressed points. The GPI is expressed in percentage, where 100% represents a normal visual field and 0% represents a perimetrically blind field, and is plotted vs patient age. Rate of progression, presented as yearly change in the GPI, is calculated by linear regression analysis. We conducted a pilot evaluation in three groups of patients: 1) eyes with developing cataract, 2) eyes without cataract, and 3) eyes in which cataract surgery was performed in the middle of the series.

RESULTS

The cut-off for pattern deviation was, at mean deviation, worse than -20 decibels (dB) in fields in which the eighty-fifth percentile of the total deviation value was significantly depressed. In the first group (n = 45), the measured rate of progression was greater with the MDI than with the GPI (P < .0001). The mean loss per year was 3.6%/year for the MDI and 2.1%/year for the GPI. In the second group (n = 42), the rate of progression did not differ between the MDI and the GPI (P = .52); the means were 2.7%/year and 2.6%/year, respectively. In the third group (n = 44), the confidence limits for the rate of progression were significantly smaller with the GPI than with the MDI (P = .04).

CONCLUSIONS

Glaucoma progression rates calculated using the GPI seem to be considerably less affected by cataract and cataract surgery than rates based on the traditional MDI.

Progression detection in glaucoma can be made more efficient by using a variable interval between successive visual field tests

BACKGROUND

This study aimed to gain insight into the optimal spacing in time for visual field tests for progression detection in glaucoma.

METHODS

Three perimetric strategies for progression detection were compared by means of simulation experiments in a theoretical cohort. In strategies 1 and 2, visual field testing was performed with fixed-spaced inter-test intervals, using intervals of 3 and 6 months respectively. In strategy 3, the inter-test interval was kept at 1 year as long as the fields appeared unchanged. Then, as soon as progression was suspected, confirmation or falsification were performed promptly. Follow-up fields were compared against a baseline assuming linear deterioration, using various progression criteria. Outcome measures were: (1) specificity, (2) time delay until the diagnosis of definite progression, and (3) number of required tests.

RESULTS

Strategies 2 and 3 had a higher specificity than strategy 1. Strategies 1 and 3 detected progression earlier than strategy 2. The number of required visual field tests was lowest for strategy 3.

CONCLUSION

Perimetry in glaucoma can be optimised by postponing the next test under apparently stable field conditions and bringing the next test forward once progression is suspected.

Normal visual field test results following glaucomatous visual field end points in the Ocular Hypertension Treatment Study

OBJECTIVE

To compare the occurrence of normal visual field (VF) test results following 2 vs 3 consecutive, abnormal, reliable test results in the Ocular Hypertension Treatment Study.

METHODS

The Ocular Hypertension Treatment Study is a prospective, multicenter follow-up study as part of a longitudinal randomized clinical trial. Sixty-four (68 eyes) of 1636 participants developed a VF primary open-angle glaucoma (POAG) end point. We compared the proportion of normal VF test results after a VF POAG end point among eyes whose VF abnormality was confirmed by 2 (n = 9 eyes) vs 3 (n = 59 eyes) consecutive, abnormal, reliable VF test results.

RESULTS

The proportion of VF test results that were normal subsequent to a VF POAG end point in eyes whose abnormality was confirmed by 2 consecutive, abnormal, reliable test results was significantly higher (73 [66%] of 110) compared with eyes whose abnormality was confirmed by 3 consecutive, abnormal, reliable test results (46 [12%] of 381) (P = .01).

CONCLUSIONS

A VF POAG end point confirmed by 3 consecutive, abnormal, reliable VF test results appears to have greater specificity and stability than either 1 or 2 consecutive, abnormal, reliable VF test results. However, some eyes whose VF POAG end point was confirmed by 3 consecutive, abnormal, reliable test results nonetheless had 1 or more normal test results on follow-up.

Longitudinal changes in the visual field and optic disc in glaucoma

The nature and mode of functional and structural progression in open-angle glaucoma is a subject of considerable debate in the literature. While there is a traditionally held viewpoint that optic disc and/or nerve fibre layer changes precede visual field changes, there is surprisingly little published evidence from well-controlled prospective studies in this area, specifically with modern perimetric and imaging techniques. In this paper, we report on clinical data from both glaucoma patients and normal controls collected prospectively over several years, to address the relationship between visual field and optic disc changes in glaucoma using standard automated perimetry (SAP), high-pass resolution perimetry (HRP) and confocal scanning laser tomography (CSLT). We use several methods of analysis of longitudinal data and describe a new technique called "evidence of change" analysis which facilitates comparison between different tests. We demonstrate that current clinical indicators of visual function (SAP and HRP) and measures of optic disc structure (CSLT) provide largely independent measures of progression. We discuss the reasons for these findings as well as several methodological issues that pose challenges to elucidating the true structure-function relationship in glaucoma.

Optical coherence tomography longitudinal evaluation of retinal nerve fiber layer thickness in glaucoma

OBJECTIVES

To longitudinally evaluate optical coherence tomography (OCT) peripapillary retinal nerve fiber layer thickness measurements and to compare these measurements across time with clinical status and automated perimetry.

METHODS

Retrospective evaluation of 64 eyes (37 patients) of glaucoma suspects or patients with glaucoma participating in a prospective longitudinal study. All participants underwent comprehensive clinical assessment, visual field (VF) testing, and OCT every 6 months. Field progression was defined as a reproducible decline of at least 2 dB in VF mean deviation from baseline. Progression of OCT was defined as reproducible mean retinal nerve fiber layer thinning of at least 20 mum.

RESULTS

Each patient had a median of 5 usable OCT scans at median follow-up of 4.7 years. The difference in the linear regression slopes of retinal nerve fiber layer thickness between glaucoma suspects and patients with glaucoma was nonsignificant for all variables; however, Kaplan-Meier survival curve analysis demonstrated a higher progression rate by OCT vs VF. Sixty-six percent of eyes were stable throughout follow-up, whereas 22% progressed by OCT alone, 9% by VF mean deviation alone, and 3% by VF and OCT.

CONCLUSIONS

A greater likelihood of glaucomatous progression was identified by OCT vs automated perimetry. This might reflect OCT hypersensitivity or true damage identified by OCT before detection by conventional methods.

Rate of visual field progression in primary open-angle glaucoma and primary angle-closure glaucoma

To estimate the rate of visual field progression in primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), we reviewed the medical records of POAG and PACG patients who had a minimum of 5-year longitudinal Goldmann visual field data. I4e and I2e isopters were quantified using grid systems. The rate of change was calculated from the slope of a linear fit to a series of average visual field scores. Twenty-three eyes of POAG patients and 25 of PACG patients were studied. The rate of visual field score change was -2.00 +/- 2.0% per year in the PACG group, and -0.81 +/- 1.0% per year in the POAG group. In these two patient groups, who were on conventional treatment at two referral hospitals, better visual field on initial presentation yielded faster progression in the POAG group, while the higher average of highest intraocular pressure in each year during follow-up was related to faster progression in the PACG group.

Progression of visual field defects and visual loss in trabeculectomized eyes

PURPOSE

To evaluate progression of visual field (VF) defects and development of visual impairment (low vision and blindness) after trabeculectomy.

METHODS

We evaluated retrospectively 138 eyes of 138 consecutive patients over 40 years of age with primary open-angle glaucoma (POAG) or exfoliation glaucoma (EG) operated on by trabeculectomy without antimetabolites. The mean follow-up period was 3.5 years (range 2-5). In 83 eyes, pre- and postoperative VF measured by the same technique were compared to detect progression. Visual acuities (VA) were recorded as Snellen decimal notations. VA of <0.3 to 0.05 was defined as low vision and VA of <0.05 or VF constricted to less than 20 degrees in diameter as blindness.

RESULTS

In 34 (41%) of 83 eyes with comparable fields, VF defects progressed because of glaucoma. In logistic regression analysis, severity of preoperative VF loss (P=0.0047) and use of preoperative oral anti-glaucomatous medication (P=0.047) correlated significantly with VF progression. In univariate analysis, also initial intraocular pressure (IOP) reduction after surgery (P=0.023) and IOP reduction from preoperative to last postoperative examination (P=0.036) were significantly smaller in eyes with VF progression. Defect progression did not, however, correlate significantly with the last IOP (P=0.58). Six eyes (4.3%) were blind due to glaucoma preoperatively and 14 eyes (10.1%) at the last follow-up. Visual impairment correlated with the severity of initial VF loss (P=0.008).

CONCLUSIONS

Progression of VF defects and development of visual impairment due to glaucoma was fairly common despite trabeculectomy. Both were associated with severity of initial VF defect. In this series, no significant correlation appeared between defect progression and the last IOP, but association between stability of VF and the amount of IOP reduction after surgery indicate that a lower target IOP level particularly in eyes with initially severe VF defect would, however, be needed.

Increased Rate of Visual Field Loss Associated with Larger Initial Visual Field Threshold Values on Follow-Up of Open-Angle Glaucoma

PURPOSE

To determine the changes in the visual field over time and the factors that contribute to these changes on follow-up of open-angle glaucoma patients.

PATIENTS AND METHODS

From a retrospective review of patients' charts and visual fields, 30 eyes from 30 patients with open-angle glaucoma with a minimum of 3 years of follow-up were chosen. Visual fields were obtained with the Octopus perimeter about every 4 months. Regression analysis was used to obtain the slope for all the threshold values for each eye for the total field and nine different regions over time. Optic disc area was measured from single fundus photographs obtained at the beginning of the period of observation.

RESULTS

The open-angle glaucomas were observed for a mean of 6.7 +/- 2.3 years. The number of visual fields per eye was 20.7 +/- 8.0. The mean threshold value of the total field for the first three visual fields was 18.0 +/- 5.2 dB. The visual fields of the 30 eyes with a mean intraocular pressure of 18 +/- 2 mm Hg during follow-up showed a significant decrease in their visual field slope of -0.384 dB/y for the total visual field. On multivariate analysis, the slope or rate of visual field loss was significantly correlated with the average of the first three initial visual field thresholds for the total visual field, temporal, and central regions so that the greater the threshold value the more rapid the rate of the visual field loss. For the total visual field and for the nasal, superior nasal, and temporal regions with lower initial threshold values, the rate of visual field loss was curvilinear with the rate of visual field loss increasing at greater initial mean threshold values. The other regions of the visual field showed a linear increasing rate of visual field loss with larger initial threshold values. Other factors significantly associated with progression of visual field loss were refractive error, race, the slope of the pulse rate, and the mean percent false positives and false negatives for initial to final observations. The mean and the slope of intraocular pressure from initial to final observation were not significant variables.

CONCLUSION

In open-angle glaucomas observed for 6.7 +/- 2.3 years, there was a more rapid rate of visual field loss associated with larger initial threshold values and a less rapid rate of visual field loss associated with smaller initial threshold values indicating that the progression of visual field loss is greater in an earlier stage of disease.

Rate and amount of visual loss in 102 patients with open-angle glaucoma followed up for at least 15 years

PURPOSE

To determine the probability of worsening of glaucoma and the rate of change in patients having open-angle glaucoma for approximately 20 years.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

One hundred and two patients diagnosed and treated for open-angle glaucoma before 1982. TESTING/INTERVENTION: The optic disc and visual field of one eye of each patient were graded independently at diagnosis and periodically throughout the follow-up period for a minimum of 15 years (mean, 19 +/- 3 years), using a scale ranging from 0 = no damage to 5 = far-advanced damage. Therapy was contemperaneous and stepped through medical laser, and surgery.

MAIN OUTCOME MEASURES

The probability of worsening by one or more stages was plotted against the length of follow-up (Kaplan-Meier survival curves).

RESULTS

Nineteen eyes did not worsen, 43 deteriorated one stage, 31 two stages, and 9 three stages. The median time to first worsening was 7.5 years, to second worsening 18.5 years, and to third worsening 24.5 years. Patients with more advanced stages of damage were not more likely to deteriorate than those with less-marked damage. The intraocular pressure was not significantly lower in the patients who remained stable. Seventeen eyes deteriorated to a visual acuity of 20/200 or worse. Of these, causes other than glaucoma were responsible in at least 60% of the cases.

CONCLUSIONS

Approximately 20% of eyes with open-angle glaucoma remained stable for about 20 years, 43% deteriorated one of five stages, and 9% three of five stages. Seventeen of the eyes lost acuity to a level of 20/200, usually from causes other than glaucoma. Deterioration of field was, on average, first noted at 7.5 years, after which the rate of deterioration slowed.

The Finnish evidence-based guideline for open-angle glaucoma

In most patients, chronic open-angle glaucoma is a slowly progressive disease. Eyes with very high intraocular pressure (IOP > 30 mmHg) represent an exception to this and should be treated and followed extremely intensively. As lowering IOP is, so far, the only means of treating glaucoma, the majority of research reports deal with the IOP-lowering effect of the treatment. The primary goal of treatment, however, is to prevent glaucomatous damage to the structures and function of the eye. The effectiveness of treatment is monitored with optic disc and retinal nerve fibre layer imaging and with visual field examinations. If the glaucomatous changes are progressing, more effective treatment should be given. In the course of follow-up, it should be noted that the changes in the optic nerve structure and function appear and progress at different time-points with delays of up to several years. The assessment of abnormalities is dependent on the examination method and requires a great deal of experience on the part of the examiner. The important risk factors in glaucoma are elevated IOP (even if IOP is within normal range in half of patients ), age, positive family history, exfoliation, race and myopia.

Progression of visual field loss in untreated glaucoma patients and glaucoma suspects in St. Lucia, West Indies

PURPOSE

A 1986-1987 survey found 8.8% prevalence of open-angle glaucoma in the black population of St. Lucia, West Indies. This follow-up study assessed visual field loss progression in untreated glaucoma patients and glaucoma suspects 10 years later.

DESIGN

Cohort study.

METHODS

Subjects were 205 glaucoma patients and suspects; 1987 data included age, sex, visual acuity, and visual fields measured by automated threshold perimetry (Humphrey C 30-2 test), and 1997 data included intraocular pressure, visual acuity, and visual fields measured by the same test. Exclusion criteria included field unreliability, field improvement due to vision improvement, nonglaucomatous vision deterioration, glaucoma treatment since 1988, and scoring of a visual field as end stage in 1987. Visual fields were scored by algorithms for the Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study (CIGTS).

RESULTS

By AGIS criteria, 55% of 146 right eyes and 52% of 141 left eyes showed progression of visual field loss. In linear regressions, progression severity was unassociated with sex, intraocular pressure, or baseline visual field score, but was positively associated with age (P <.001, right; P =.002, left). The cumulative probability of reaching end stage in 10 years in at least one eye was approximately 16% by AGIS criteria. By CIGTS criteria, 73% of 146 right eyes and 72% of 141 left eyes progressed.

CONCLUSIONS

These data provide a unique opportunity to study progression of untreated glaucoma. The percentage of eyes showing visual field loss progression and the percentage reaching end stage were considerably higher than in studies of visual field progression in treated eyes.

Identification of progressive glaucomatous visual field loss

In normal individuals, visual field measures are not perfectly repeatable and individual test locations exhibit both short- and long-term sensitivity variations. This physiologic variability is greatly increased in glaucoma and confounds detection of real progressive loss in visual function. Distinguishing progressive glaucomatous visual field loss from test variability therefore represents a complex task. Procedures used for detection of glaucomatous visual field progression may be broadly grouped into four categories: 1) clinical judgment, which consists of simple subjective observation of sequential visual field test results; 2) defect classification systems, whereby specific criteria are used to stratify field loss by discrete score and define progression as score change over time, such as the Advanced Glaucoma Intervention Study scoring system; 3) trend analyses, which follow test parameters sequentially over time to determine the magnitude and significance of patterns within the data, for example linear regression; and 4) event analyses, which identify single events of significant change relative to a reference examination. All of these methods demonstrate distinct benefits and drawbacks, making each useful in specific circumstances, although no single method appears universally ideal. At the present time the best method of detection of progression may be to rely upon confirmation of change at successive examinations and also by correlation of visual field changes with other clinical observations. Alternative analysis methods may become available in the near future to help identify cases of progressive loss.

Sensitivity differences between real-patient and computer-stimulated visual fields

PURPOSE

The authors sought to verify computer simulation of visual fields by comparing thresholds of real and corresponding simulated visual fields.

METHODS

Four patients with stable glaucomatous visual fields and three patients with progressing glaucomatous visual fields were chosen for the study. Visual fields had been recorded at 6-month intervals for 5 to 7.5 years. A previously described computer simulation program was used to generate a corresponding simulated visual field for each of the real fields. Twenty different levels of response variability and long-term variability were used in the simulations. Pointwise sensitivity differences between real and simulated fields were calculated. The average difference and 95% interval of the differences were analyzed for the different simulation conditions, for the pointwise sensitivities in the real patient fields, and to determine whether the field was stable or progressing.

RESULTS

In almost all simulation conditions, the average pointwise sensitivity differences ranged from -1 to 1 dB and were not significantly different among different simulation conditions. The 95% interval of the average difference increased significantly with response variability, whereas long-term variability failed to show any apparent effect. Average pointwise differences and the 95% intervals were greatest in locations where the real-patient field had reduced sensitivity of 14 dB or worse.

CONCLUSION

The simulation program provided good estimates of visual field sensitivities. Increasing amounts of response, but not long-term variability, produced a linear increase in the variability of threshold sensitivities. This finding implies that short-term rather than long-term fluctuation is the most important factor determining the variability of thresholds.

Visual field defects and neural losses from experimental glaucoma

Glaucoma is a relatively common disease in which the death of retinal ganglion cells causes a progressive loss of sight, often leading to blindness. Typically, the degree of a patient's visual dysfunction is assessed by clinical perimetry, involving subjective measurements of light-sense thresholds across the visual field, but the relationship between visual and neural losses is inexact. Therefore, to better understand of the effects of glaucoma on the visual system, a series of investigations involving psychophysics, electrophysiology, anatomy, and histochemistry were conducted on experimental glaucoma in monkeys. The principal results of the studies showed that, (1) the depth of visual defects with standard clinical perimetry are predicted by a loss of probability summation among retinal detection mechanisms, (2) glaucomatous optic atrophy causes a non-selective reduction of metabolism of neurons in the afferent visual pathway, and (3) objective electrophysiological methods can be as sensitive as standard clinical perimetry in assessing the neural losses from glaucoma. These experimental findings from glaucoma in monkeys provide fundamental data that should be applicable to improving methods for assessing glaucomatous optic neuropathy in patients.

Rate of visual field loss and long-term visual outcome in primary open-angle glaucoma

PURPOSE

To evaluate long-term visual field outcome in primary open-angle glaucoma.

METHODS

In this retrospective cohort study, 40 eyes of 40 patients with primary open-angle glaucoma with elevated intraocular pressure and a minimum of 8-year longitudinal series of visual fields were plotted with Goldmann perimeter. Eyes with any other ocular disease except cataract were excluded. Manual grid templates were used to quantify the visual fields. Linear regression was performed to estimate the rate of visual field decline. Pertinent clinical factors were evaluated for statistical association with the rate of decline. Long-term clinical outcome including visual acuity, rate of legal blindness, and rate of medical and surgical interventions was also measured.

RESULTS

In the 40 eyes studied, with a mean follow-up of 14 years, the visual field score decreased at the rate of -1.5% per year. Overall, 68% showed significant decrease, and the rate of decrease among these eyes was -2.1% per year. Five eyes became legally blind from glaucoma; the cumulative rate of blindness from glaucoma was 19% at 22 years. Higher intraocular pressure and greater number of antiglaucoma medications on initial presentation were associated with faster and slower deterioration of visual field (compared with the average), respectively.

CONCLUSIONS

With standard glaucoma therapy, the rate of visual field loss in primary open-angle glaucoma is slow. Lower intraocular pressure and more antiglaucoma medications are associated with slower visual field decline. Legal blindness from glaucoma is 19% over a follow-up of 22 years.

Deprivation and late presentation of glaucoma: case-control study

OBJECTIVE

To identify socioeconomic risk factors for first presentation advanced glaucomatous visual field loss.

DESIGN

Hospital based case-control study with prospective identification of patients.

SETTING

Three hospital eye departments.

PARTICIPANTS

Consecutive patients newly diagnosed with glaucoma (n=220). Cases (late presenters) were those presenting with advanced glaucoma (n=110), controls were those with early glaucoma (n=110).

RESULTS

Median underprivileged area scores were higher among late presenters (29.5; interquartile range 9.0-42.2) than in the control group (21.3; 6.1-37.4) (P=0.035). Late presenters were more likely to be of lower occupational class (odds ratio adjusted for age and referral centre 20.1 (95% confidence interval 2.6 to 155) for group III compared with group I-II and 86.0 (11.0 to 673 for group IV-V compared with group I-II), to have no access to a car (2.2; 1.2 to 4.0), to have left full time education at age 14 or less (7.5; 2.3 to 24.7), and to be tenants rather than owner occupiers (local authority tenants 3.2; 1.7 to 5.8, private tenants 2.1; 0.7 to 5.8). Effects of deprivation were partly accounted for by family history of glaucoma, time since last visit to an optometrist, and lack of an initial diagnosis of glaucoma by an optometrist.

CONCLUSIONS

Area and individual level deprivation were both associated with late presentation of glaucoma. Existing evidence shows that late presentation is an important risk factor for subsequent blindness. Deprived groups thus seem to be at greater risk of going blind from glaucoma. Material deprivation may be associated with more aggressive disease as well as later presentation.

Visual field progression in patients with initially unilateral visual field loss from chronic open-angle glaucoma

PURPOSE

To investigate visual field progression in patients with initially unilateral glaucomatous visual field loss, and to determine risk factors for progression.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Forty-eight consecutive patients with primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma, seen over an 18-month period, who initially had unilateral visual field loss as defined by use of modified Anderson criteria. Patients were followed with standard Humphrey perimetry for a minimum of 2 years.

METHODS

Progression was defined by use of modified Anderson criteria, and Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study scores.

MAIN OUTCOME MEASURE

Visual field progression.

RESULTS

Three patients (6.2%) had fellow eye progression over a mean follow-up of 76 months and duration of disease of 8.7 years. Fellow eye progression correlated with progression of the first-affected eye (P = 0.044). Ten patients (21%) had progression of the first-affected eye; these eyes had a larger initial cup/disc ratio compared with stable eyes (P = 0.041). Increasing initial AGIS score was associated with progression (P: = 0.003). Kaplan-Meier survival analysis estimated the risk of progression at 5 years to be 25% in first-affected eyes and 7.2% in fellow eyes.

CONCLUSIONS

In this population, the risk of fellow eye progression in patients with initially unilateral visual field loss from open-angle glaucoma is low. Progression is higher in eyes with visual field loss at initial testing, and the risk of progression increases as the level of initial visual field loss increases.