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.

Neuroretinal Rim Area Change in Glaucoma Patients With Visual Field Progression Endpoints and Intraocular Pressure Reduction. The Canadian Glaucoma Study: 4.

PURPOSE: To compare rim area rates in patients with and without the visual field (VF) progression endpoint in the Canadian Glaucoma Study and determine whether intraocular pressure (IOP) reduction following the endpoint altered rim area rate. DESIGN: Prospective multicenter cohort study. METHODS: setting: University hospitals. PATIENT POPULATION: Two hundred and six patients with open-angle glaucoma were examined at 4-month intervals with standard automated perimetry and confocal scanning laser tomography. INTERVENTION: After the endpoint, IOP was reduced by ≥20%. OUTCOME MEASURES: Univariate analysis for change in rim area rate and multivariable analysis to adjust for independent covariates (eg, age, sex, and IOP). RESULTS: Patients with an endpoint (n = 59) had a worse rim area rate prior to the endpoint compared to those without (n = 147; median [interquartile range]: -14 [-32, 11] × 10(-3) mm(2)/y and -5 [-14, 5] × 10(-3) mm(2)/y, respectively, P = .02). In univariate analysis, there was no difference in rim area rate before and after the endpoint (median difference [95% CI], 8 (-10, 24) × 10(-3) mm(2)/y), but the muItivariate analysis showed that IOP reduction >2 mm Hg after the endpoint was strongly linked to a reduction in rim area rate decline (8 × 10(-3) mm(2)/y for each additional 1 mm Hg reduction). CONCLUSIONS: Patients with a VF endpoint had a median rim area rate that was nearly 3 times worse than those without an endpoint. Lower mean follow-up IOP was independently associated with a slower decline in rim area.

Validity, reliability, and repeatability of the useful field of view test in persons with normal vision and patients with glaucoma.

PURPOSE: To determine the validity, test-retest reliability and repeatability of the UFOV test in healthy controls and glaucoma patients. METHODS: Three substudies with the UFOV test were conducted: (1) validity was evaluated in 77 older controls (mean age 64 [SD, 7] years) and 53 glaucoma patients (mean age 69 [SD, 8] years); (2) test-retest reliability was evaluated in 13 young controls (mean age 28 [SD, 4] years), 21 older controls (mean age 66 [SD, 9] years), and 22 glaucoma patients (mean age 68 [SD, 8] years) who performed the test twice within approximately two weeks; (3) repeatability was evaluated in 17 young controls (mean age 33 [SD, 8] years) who performed the test five times on the same day. RESULTS: In the validity substudy, mean total processing time was significantly less for older controls (358.3 ms [SD, 226.8 ms]), than glaucoma patients (580.2 ms [SD, 324.5 ms]), with moderate correlations (rho ≥ 0.40) between total processing time and age, and visual field impairment. In the reliability substudy, mean total processing time was significantly less on retest (P ≤ 0.02), with glaucoma patients showing the largest mean test-retest difference (144.7 ms [SD, 168.9 ms]) compared with young (31.5 ms [SD, 43.7 ms]) and older controls (56.2 ms [SD, 74.8 ms]). The 95% limits of agreement were significantly wider for glaucoma patients (-186.3 and +475.7 ms) compared with young (-54.1 and +117.1 ms) and older controls (-90.5 and +202.9 ms), (P < 0.01). In the repeatability substudy, performance remained constant after the second of five tests (differences in mean total processing time <6 ms). CONCLUSIONS: Measurement properties of the UFOV test are important for assessing functional performance, in particular, fitness to drive. Our results indicate moderate variability, greater for glaucoma patients than healthy controls, and a learning effect. Two consecutive tests are suggested to establish reliable baseline measures.

Rates of change in the visual field and optic disc in patients with distinct patterns of glaucomatous optic disc damage.

PURPOSE: To investigate the rate of visual field and optic disc change in patients with distinct patterns of glaucomatous optic disc damage. DESIGN: Prospective longitudinal study. PARTICIPANTS: A total of 131 patients with open-angle glaucoma with focal (n = 45), diffuse (n = 42), and sclerotic (n = 44) optic disc damage. METHODS: Patients were examined every 4 months with standard automated perimetry (SAP, SITA Standard, 24-2 test, Humphrey Field Analyzer, Carl Zeiss Meditec, Dublin, CA) and confocal scanning laser tomography (CSLT, Heidelberg Retina Tomograph, Heidelberg Engineering GmbH, Heidelberg, Germany) for a period of 4 years. During this time, patients were treated according to a predefined protocol to achieve a target intraocular pressure (IOP). Rates of change were estimated by robust linear regression of visual field mean deviation (MD) and global optic disc neuroretinal rim area with follow-up time. MAIN OUTCOME MEASURES: Rates of change in MD and rim area. RESULTS: Rates of visual field change in patients with focal optic disc damage (mean -0.34, standard deviation [SD] 0.69 dB/year) were faster than in patients with sclerotic (mean -0.14, SD 0.77 dB/year) and diffuse (mean +0.01, SD 0.37 dB/year) optic disc damage (P = 0.003, Kruskal-Wallis). Rates of optic disc change in patients with focal optic disc damage (mean -11.70, SD 25.5 ×10(-3) mm(2)/year) were faster than in patients with diffuse (mean -9.16, SD 14.9 ×10(-3) mm(2)/year) and sclerotic (mean -0.45, SD 20.6 ×10(-3) mm(2)/year) optic disc damage, although the differences were not statistically significant (P = 0.11). Absolute IOP reduction from untreated levels was similar among the groups (P = 0.59). CONCLUSIONS: Patients with focal optic disc damage had faster rates of visual field change and a tendency toward faster rates of optic disc deterioration when compared with patients with diffuse and sclerotic optic disc damage, despite similar IOP reductions during follow-up.

Canadian Glaucoma Study: 3. Impact of risk factors and intraocular pressure reduction on the rates of visual field change.

OBJECTIVES: To determine rates of visual field change associated with risk factors for progression in the Canadian Glaucoma Study (abnormal anticardiolipin antibody level, age, female sex, and mean follow-up intraocular pressure [IOP]), and to evaluate the effect of IOP reduction on subsequent rates of visual field change in progressing patients. METHODS: Two hundred sixteen patients (median age, 65.2 years) were followed up at 4-month intervals with perimetry and were monitored for progression. Patients reaching an end point based on total deviation analysis underwent 20% or greater reduction in IOP. Rates of mean deviation (MD) change were calculated. RESULTS: Patients with 0, 1, and 2 end points had a median of 18, 23, and 25 examinations, respectively. The median MD rate in progressing patients prior to the first end point was significantly worse compared with those with no progression (-0.35 and 0.05 dB/y, respectively). An abnormal anticardiolipin antibody level was associated with a significantly worse MD rate compared with a normal anticardiolipin antibody level (-0.57 and -0.03 dB/y, respectively). Increasing age was associated with a worse MD rate, but female sex and mean follow-up IOP were not. After the first end point, the median IOP decreased from 18.0 to 14.8 mm Hg (20% in individual patients), resulting in a significant MD rate change from -0.36 to -0.11 dB/y. CONCLUSIONS: Patients with abnormal anticardiolipin antibody levels and increasing age had faster visual field change. Modest IOP reduction in progressing patients significantly ameliorated the rate of visual field decline. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00262626.

Optic disc progression in glaucoma: comparison of confocal scanning laser tomography to optic disc photographs in a prospective study.

PURPOSE: To compare confocal scanning laser tomography (CSLT) to optic disc photography for detecting progressive glaucomatous disc changes. METHODS: Four expert observers first examined a training set of 40 pairs of monoscopic disc photographs to help set a criterion for change. They then classified 44 pairs of monoscopic photographs of patients followed prospectively as having either definitely no change, probably no change, probably change, or definitely change (score, 0, 1, 2, or 3, respectively). Observers were unaware that 10 pairs were photographs of fellow eyes obtained the same day to measure specificity. These patients were imaged with the Heidelberg Retina Tomograph every 6 months. Topographic change analysis (TCA) software with three criteria (yielding specificity of 81%, 94%, or 97%) was used. Comparisons between the TCA results and those of observers were made for a range of liberal to conservative criteria and for individual and combined observer scores. RESULTS: The median follow-up was 9.0 years with 18 CSLT images. Observer specificity varied from 50% to 90% (using score 0) and 60% to 100% (using score 0 or 1). Interobserver kappa ranged from 0.22 to 0.38 from the most liberal to conservative criterion and was generally higher than corresponding TCA-observer agreement. For most criteria, observers had either a high hit rate with low specificity or high specificity with a low hit rate compared with the TCA. Similar results were obtained when observer scores were combined to derive a broader range of criteria. CONCLUSIONS: The results indicate that the TCA performs at least as well as either the individual or best combination of observer classifications of disc photographs.

Canadian Glaucoma Study: 2. risk factors for the progression of open-angle glaucoma.

OBJECTIVE: To determine systemic and ocular risk factors for visual field progression in open-angle glaucoma. METHODS: In the Canadian Glaucoma Study, a multicenter prospective longitudinal study of 258 patients (131 men and 127 women; median age, 65.0 years), baseline systemic measures included assessment of peripheral vasospasm and markers for hematopathology, coagulopathy, and immunopathology. Patients were followed up at 4-month intervals with perimetry, optic disc imaging, and a standardized interventional protocol for intraocular pressure control. Univariate and proportional hazards models were used to identify factors that predicted progression. MAIN OUTCOME MEASURE: Visual field progression with standard automated perimetry. RESULTS: Median follow-up was 5.3 years, with 167 patients (64.7%) completing 5 years or more and 67 patients (26.0%) completing 7 years or more. Abnormal baseline anticardiolipin antibody levels (hazard ratio [HR], 3.86; 95% confidence interval [CI], 1.60-9.31), higher baseline age (HR per year, 1.04; 95% CI, 1.01-1.07), female sex (HR, 1.94; 95% CI, 1.09-3.46), and higher mean follow-up intraocular pressure (HR per 1 mm Hg, 1.19; 95% CI, 1.05-1.36) before progression were associated with progression. CONCLUSIONS: The Canadian Glaucoma Study identified 4 independent predictive factors for glaucomatous field progression. Application to Clinical Practice While confirming the importance of intraocular pressure in glaucoma progression, this study determined other risk factors that merit awareness.

Glaucoma and on-road driving performance.

PURPOSE: To investigate the on-road driving performance of patients with glaucoma. METHODS: The sample comprised 20 patients with glaucoma and 20 subjects with normal vision, all licensed drivers, matched for age and sex. Driving performance was tested over a 10-km route incorporating 55 standardized maneuvers and skills through residential and business districts of Halifax, Nova Scotia, Canada. Testing was conducted by a professional driving instructor and assessed by an occupational therapist certified in driver rehabilitation, masked to participant group membership and level of vision. Main outcome measures were total number of satisfactory maneuvers and skills, overall rating, and incidence of at-fault critical interventions (application of the dual brake and/or steering override by the driving instructor to prevent a potentially unsafe maneuver). Measures of visual function included visual acuity, contrast sensitivity, and visual fields (Humphrey Field Analyzer; Carl Zeiss Meditec, Inc., Dublin, CA; mean deviation [MD] and binocular Esterman points). RESULTS: There was no significant difference between patients with glaucoma (mean MD = -1.7 dB [SD 2.2] and -6.5 dB [SD 4.9], better and worse eyes, respectively) and control subjects in total satisfactory maneuvers and skills (P = 0.65), or overall rating (P = 0.60). However, 12 (60%) patients with glaucoma had one or more at-fault critical interventions, compared with 4 (20%) control subjects (odds ratio = 6.00, 95% CI, 1.46-24.69; higher still after adjustment for age, sex, medications and driving exposure), the predominant reason being failure to see and yield to a pedestrian. In the glaucoma group, worse-eye MD was associated with the overall rating of driving (r = 0.66, P = 0.002). CONCLUSIONS: This sample of patients with glaucoma with slight to moderate visual field impairment performed many real-world driving maneuvers safely. However, they were six times as likely as subjects with normal vision to have a driving instructor intervene for reasons suggesting difficulty with detection of peripheral obstacles and hazards and reaction to unexpected events.

A Canadian glaucoma strategy.

BACKGROUND: To develop Canadian guidelines for the management of primary open-angle glaucoma and provide a quick and practical reference for physicians in the office setting. METHODS: A Canadian Glaucoma Strategy began with a review of the literature and existing guidelines, as well as consultation with glaucoma specialists and general ophthalmologists across Canada. The resulting information was assessed by a panel of glaucoma experts and general ophthalmologists at the Canadian Glaucoma Strategy Forum to distill what was learned and construct the algorithms of care. RESULTS: A Canadian Glaucoma Strategy was developed in 4 algorithms. First, patients are diagnosed on the basis of risk assessment and clinical findings. The staging algorithm is designed to determine the disease stage, while the treatment and follow-up algorithms focus on control of intraocular pressure and continuing patient follow-up. INTERPRETATION: A Canadian Glaucoma Strategy is a practical series of algorithms that can be at hand in the office setting, providing the general ophthalmologist with an up-to-date guide for the management of patients with glaucoma concerns.

Risk of falls and motor vehicle collisions in glaucoma.

PURPOSE: To investigate the risk of falls and motor vehicle collisions (MVCs) in patients with glaucoma. METHODS: The sample comprised 48 patients with glaucoma (mean visual field mean deviation [MD] in the better eye = -3.9 dB; 5.1 dB SD) and 47 age-matched normal control subjects, who were recruited from a university-based hospital eye care clinic and are enrolled in an ongoing prospective study of risk factors for falls, risk factors for MVCs, and on-road driving performance in glaucoma. Main outcome measures at baseline were previous self-reported falls and MVCs, and police-reported MVCs. Demographic and medical data were obtained. In addition, functional independence in daily living, physical activity level and balance were assessed. Clinical vision measures included visual acuity, contrast sensitivity, standard automated perimetry, useful field of view (UFOV), and stereopsis. Analyses of falls and MVCs were adjusted to account for the possible confounding effects of demographic characteristics, medications, and visual field impairment. MVC analyses were also adjusted for kilometers driven per week. RESULTS: There were no significant differences between patients with glaucoma and control subjects with respect to number of systemic medical conditions, body mass index, functional independence, and physical activity level (P > 0.10). At baseline, 40 (83%) patients with glaucoma and 44 (94%) control subjects were driving. Compared with control subjects, patients with glaucoma were over three times more likely to have fallen in the previous year (odds ratio [OR](adjusted) = 3.71; 95% CI, 1.14-12.05), over six times more likely to have been involved in one or more MVCs in the previous 5 years (OR(adjusted) = 6.62; 95% CI, 1.40-31.23), and more likely to have been at fault (OR(adjusted) = 12.44; 95% CI, 1.08-143.99). The strongest risk factor for MVCs in patients with glaucoma was impaired UFOV selective attention (OR(adjusted) = 10.29; 95% CI, 1.10-96.62; for selective attention >350 ms compared with

Effect of moderate intraocular pressure changes on topographic measurements with confocal scanning laser tomography in patients with glaucoma.

OBJECTIVE: To evaluate optic disc topography changes after intraocular pressure (IOP) modulation in patients with glaucoma. METHODS: Twenty-three patients with glaucoma were studied. Three mean optic disc topography images were obtained with the Heidelberg Retina Tomograph II at baseline and weeks 1, 2, 4, and 8 (visits 1, 2, 3, 4, and 5, respectively). Topical medications were discontinued in the study eye after visit 1 and resumed after visit 4 but maintained in the contralateral control eye. Central corneal thickness was measured at the last visit. Topographic changes were determined by stereometric parameters (rim area and mean cup depth) and at discrete topographic locations using the Topographic Change Analysis program (from the Heidelberg Retina Tomograph II). RESULTS: In the study eyes, IOP increased significantly (5.4 mm Hg at visit 4; P<.001) after withdrawal of topical medications but returned to baseline levels after resuming medications; no statistically significant topographic changes, however, were observed. Moreover, no relationship between change in IOP and stereometric parameters was observed. Central corneal thickness was not associated with changes in optic disc topography induced by IOP modulation. CONCLUSION: In patients with glaucoma, significant but relatively moderate IOP increases and decreases on the order of 5 mm Hg did not appear to have an effect on optic disc topography.

The letter contrast sensitivity test: clinical evaluation of a new design.

PURPOSE: To compare the reliability, validity, and responsiveness of the Mars Letter Contrast Sensitivity (CS) Test to the Pelli-Robson CS Chart. METHODS: One eye of 47 normal control subjects, 27 patients with open-angle glaucoma, and 17 with age-related macular degeneration (AMD) was tested twice with the Mars test and twice with the Pelli-Robson test, in random order on separate days. In addition, 17 patients undergoing cataract surgery were tested, once before and once after surgery. RESULTS: The mean Mars CS was 1.62 log CS (0.06 SD) for normal subjects aged 22 to 77 years, with significantly lower values in patients with glaucoma or AMD (P<0.001). Mars test-retest 95% limits of agreement (LOA) were +/-0.13, +/-0.19, and +/-0.24 log CS for normal, glaucoma, and AMD, respectively. In comparison, Pelli-Robson test-retest 95% LOA were +/-0.18, +/-0.19, and +/-0.33 log CS. The Spearman correlation between the Mars and Pelli-Robson tests was 0.83 (P<0.001). However, systematic differences were observed, particularly at the upper-normal end of the range, where Mars CS was lower than Pelli-Robson CS. After cataract surgery, Mars and Pelli-Robson effect size statistics were 0.92 and 0.88, respectively. CONCLUSIONS: The results indicate the Mars test has test-retest reliability equal to or better than the Pelli-Robson test and comparable responsiveness. The strong correlation between the tests provides evidence the Mars test is valid. However, systematic differences indicate normative values are likely to be different for each test. The Mars Letter CS Test is a useful and practical alternative to the Pelli-Robson CS Chart.

Visual field progression in glaucoma: total versus pattern deviation analyses.

PURPOSE: To compare visual field progression with total and pattern deviation analyses in a prospective longitudinal study of patients with glaucoma and healthy control subjects. METHODS: A group of 101 patients with glaucoma (168 eyes) with early to moderately advanced visual field loss at baseline (average mean deviation [MD], -3.9 dB) and no clinical evidence of media opacity were selected from a prospective longitudinal study on visual field progression in glaucoma. Patients were examined with static automated perimetry at 6-month intervals for a median follow-up of 9 years. At each test location, change was established with event and trend analyses of total and pattern deviation. The event analyses compared each follow-up test to a baseline obtained from averaging the first two tests, and visual field progression was defined as deterioration beyond the 5th percentile of test-retest variability at three test locations, observed on three consecutive tests. The trend analyses were based on point-wise linear regression, and visual field progression was defined as statistically significant deterioration (P < 5%) worse than -1 dB/year at three locations, confirmed by independently omitting the last and the penultimate observation. The incidence and the time-to-progression were compared between total and pattern deviation analyses. To estimate the specificity of the progression analyses, identical criteria were applied to visual fields obtained in 102 healthy control subjects, and the rate of visual field improvement was established in the patients with glaucoma and the healthy control subjects. RESULTS: With both event and trend methods, pattern deviation analyses classified approximately 15% fewer eyes as having progressed than did the total deviation analyses. In eyes classified as progressing by both the total and pattern deviation methods, total deviation analyses tended to detect progression earlier than the pattern deviation analyses. A comparison of the changes observed in MD and the visual fields' general height (estimated by the 85th percentile of the total deviation values) confirmed that change in the glaucomatous eyes almost always comprised a diffuse component. Pattern deviation analyses of progression may therefore underestimate the true amount of glaucomatous visual field progression. CONCLUSIONS: Pattern deviation analyses of visual field progression may underestimate visual field progression in glaucoma, particularly when there is no clinical evidence of increasing media opacity. Clinicians should have access to both total and pattern deviation analyses to make informed decisions on visual field progression in glaucoma.

Effect of cataract extraction on the visual fields of patients with glaucoma.

OBJECTIVE: To investigate the effect of cataract extraction on the visual fields of patients with open-angle glaucoma. METHODS: Patients in a prospective cohort study in a tertiary center underwent standard automated perimetry every 6 months. We compared the mean results of the 2 examinations immediately before and 2 examinations immediately after phacoemulsification cataract extraction and intraocular lens implant (effect analysis) and the mean results of the first 2 and last 2 examinations from 4 consecutive examinations obtained more than 1 year after the cataract surgery (control analysis). RESULTS: Our sample contained 34 eyes of 26 patients (mean +/- SD age, 69.2 +/- 10.8 years). While the mean logMAR best-corrected visual acuity improved significantly by approximately 2 Snellen lines after surgery (P < .001), the average change in mean deviation in both the effect and control analyses was less than 0.1 dB and not statistically significant (P = .85). There was a strong correlation between change in foveal sensitivity and change in mean deviation in the effect analysis but not in the control analysis (r = 0.76 [P < .001] and r = 0.30 [P = .08], respectively). There was no relationship between change in visual acuity or initial mean deviation and change in mean deviation in either analysis. Change in pointwise total deviation was not systematically related to the respective baseline value in either analysis; however, the variance of the distribution of change in total deviation was significantly higher in the effect analysis (P < .001). CONCLUSION: While there was an improvement in best-corrected visual acuity after cataract surgery, the changes in the visual field as a group were negligible.

Threshold and variability properties of matrix frequency-doubling technology and standard automated perimetry in glaucoma.

PURPOSE: To compare test results from second-generation Frequency-Doubling Technology perimetry (FDT2, Humphrey Matrix; Carl-Zeiss Meditec, Dublin, CA) and standard automated perimetry (SAP) in patients with glaucoma. Specifically, to examine the relationship between visual field sensitivity and test-retest variability and to compare total and pattern deviation probability maps between both techniques. METHODS: Fifteen patients with glaucoma who had early to moderately advanced visual field loss with SAP (mean MD, -4.0 dB; range, +0.2 to -16.1) were enrolled in the study. Patients attended three sessions. During each session, one eye was examined twice with FDT2 (24-2 threshold test) and twice with SAP (Swedish Interactive Threshold Algorithm [SITA] Standard 24-2 test), in random order. We compared threshold values between FDT2 and SAP at test locations with similar visual field coordinates. Test-retest variability, established in terms of test-retest intervals and standard deviations (SDs), was investigated as a function of visual field sensitivity (estimated by baseline threshold and mean threshold, respectively). The magnitude of visual field defects apparent in total and pattern deviation probability maps were compared between both techniques by ordinal scoring. RESULTS: The global visual field indices mean deviation (MD) and pattern standard deviation (PSD) of FDT2 and SAP correlated highly (r > 0.8; P < 0.001). At test locations with high sensitivity (>25 dB with SAP), threshold estimates from FDT2 and SAP exhibited a close, linear relationship, with a slope of approximately 2.0. However, at test locations with lower sensitivity, the relationship was much weaker and ceased to be linear. In comparison with FDT2, SAP showed a slightly larger proportion of test locations with absolute defects (3.0% vs. 2.2% with SAP and FDT2, respectively, P < 0.001). Whereas SAP showed a significant increase in test-retest variability at test locations with lower sensitivity (P < 0.001), there was no relationship between variability and sensitivity with FDT2 (P = 0.46). In comparison with SAP, FDT2 exhibited narrower test-retest intervals at test locations with lower sensitivity (SAP thresholds <25 dB). A comparison of the total and pattern deviation maps between both techniques showed that the total deviation analyses of FDT2 may slightly underestimate the visual field loss apparent with SAP. However, the pattern-deviation maps of both instruments agreed well with each other. CONCLUSIONS: The test-retest variability of FDT2 is uniform over the measurement range of the instrument. These properties may provide advantages for the monitoring of patients with glaucoma that should be investigated in longitudinal studies.

Glaucomatous visual field progression with frequency-doubling technology and standard automated perimetry in a longitudinal prospective study.

PURPOSE: To compare frequency-doubling technology (FDT) perimetry with standard automated perimetry (SAP) for detecting glaucomatous visual field progression in a longitudinal prospective study. METHODS: One eye of patients with open-angle glaucoma was tested every 6 months with both FDT and SAP. A minimum of 6 examinations with each perimetric technique was required for inclusion. Visual field progression was determined by two methods: glaucoma change probability (GCP) analysis and linear regression analysis (LRA). For GCP, several criteria for progression were used. The number of locations required to classify progression with FDT compared with SAP, respectively, was 1:2 (least conservative), 1:3, 2:3, 2:4, 2:6, 2:7, 3:6, 3:7, and 3:10 (most conservative). The number of consecutive examinations required to confirm progression was 2-of-3, 2-of-2, and 3-of-3. For LRA, the progression criterion was any significant decline in mean threshold sensitivity over time in each of the following three visual field subdivisions: (1) all test locations, (2) locations in the central 10 degrees and the superior and inferior hemifields, and (3) locations in each quadrant. Using these criteria, the proportion of patients classified as showing progression with each perimetric technique was calculated and, in the case of progression with both, the differences in time to progression were determined. RESULTS: Sixty-five patients were followed for a median of 3.5 years (median number of examinations, 9). For the least conservative GCP criterion, 32 (49%) patients were found to have progressing visual fields with FDT and 32 (49%) patients with SAP. Only 16 (25%) patients showed progression with both methods, and in most of those patients, FDT identified progression before SAP (median, 12 months earlier). The majority of GCP progression criteria (15/27), classified more patients as showing progression with FDT than with SAP. Contrary to this, more patients showed progression with SAP than FDT, when analysed with LRA; e.g., using quadrant LRA 20 (31%) patients showed progression with FDT, 23 (35%) with SAP, and only 10 (15%) with both. CONCLUSIONS: FDT perimetry detected glaucomatous visual field progression. However, the proportion of patients who showed progression with both FDT and SAP was small, possibly indicating that the two techniques identify different subgroups of patients. Using GCP, more patients showed progression with FDT than with SAP, yet the opposite occurred using LRA. As there is no independent qualifier of progression, FDT and SAP progression rates vary depending on the method of analysis and the criterion used.

Factors associated with optic disc hemorrhages in glaucoma.

PURPOSE: To evaluate factors associated with optic disc hemorrhages (ODHs) in patients with open-angle glaucoma. DESIGN: Cohort study. PARTICIPANTS: One hundred thirty-seven patients with open-angle glaucoma, with an initial mean age of 60.0 years (standard deviation [SD], 11.0 years) followed up for a mean of 9.5 years (SD, 5.0 years). METHODS: The association between ODHs and various patient-related variables (diabetes, systemic hypertension, heart disease, hypercholesterolemia, migraine, hypothyroidism, use of platelet antiaggregant agents) and eye-related variables (mean and range of intraocular pressure, refractive error, and severity of disease) was investigated using multivariate time-to-event analyses in patients with open-angle glaucoma. To determine the influence of the level of intraocular pressure (IOP) on the occurrence of ODHs, we compared the IOP at the time the first ODH was noted with the mean IOP of the previous 3 visits. As a control, a similar analysis was performed on the same eyes using a randomly selected visit before the occurrence of the first ODH. MAIN OUTCOME MEASUREMENTS: Patient-related and eye-related variables associated with ODHs and the comparative level of IOP in which these ODHs were observed. RESULTS: Fifty eyes of 38 patients (28%) had 1 or more ODHs during the follow-up period. The ODHs were associated with presence of diabetes (hazard ratio, 4.43; 95% confidence interval [CI], 1.8-10.50; P = 0.001) and use of aspirin (hazard ratio, 2.30; 95% CI, 1.2-4.6; P = 0.019). The IOP at the time of the first ODH was, on average, 1.4 mmHg lower than the mean IOP of the 3 previous visits (95% CI, -2.2 to -0.6 mmHg; P<0.001), whereas in the control analysis, the respective value was 0.3 mmHg lower (95% CI, -1.0 to 0.5; P = 0.410). CONCLUSIONS: Optic disc hemorrhages were associated with diabetes and aspirin use and were observed at relatively lower IOP during follow-up.

Enhancing vision care integration: 1. Development of practice algorithms.

BACKGROUND: Appropriate access to the best quality of vision care is enhanced when patients receive eye care services from the right professional, at the right time, and in the right place. This paper, the first in a two-part series, describes the development of an integrated framework for vision care delivery. Specifically, two patient-centred vision care algorithms for the multidisciplinary management of diabetic retinopathy and the red eye are outlined, and the process that resulted in their development is described. METHODS: The method used relies on a description of a multidisciplinary collaboration that occurred among ophthalmologists, optometrists, general practitioners and representatives of the Nova Scotia Department of Health with the aim of developing an integrated patient-focused multidisciplinary framework for vision care delivery. RESULTS: The process of collaborative negotiation among the four groups resulted in the development of multidisciplinary algorithms for the screening of patients with diabetes mellitus and the treatment of those presenting with a red eye. INTERPRETATION: Professional scope of practice has always been a contentious issue among health care professions. However, where parties agree to work within an atmosphere of respect and to accept guidance in areas of disagreement from a third party respected by all, compromise is possible. The result was the development of two vision care algorithms and ongoing efforts on the development of other algorithms.

Enhancing vision care integration: 2. Implementation of practice algorithms.

BACKGROUND: Appropriate access to the best quality of vision care is enhanced when patients receive eye care services from the right professional, at the right time, and in the right place. In the preceding article the authors describe the development of two patient-centred vision care algorithms for the multidisciplinary management of diabetic retinopathy and red eye. Subsequently, a questionnaire survey was done to determine ophthalmologist, optometrist and general practitioner (GP) familiarity with and acceptance of the vision care algorithms. METHODS: The survey was conducted in the summer of 2001 among all ophthalmologists, optometrists and GPs registered with their respective professional body in Nova Scotia to assess their knowledge and acceptance of the diabetes mellitus and red eye algorithms. They were also asked to indicate their preferred method(s) of education and dissemination regarding these and future algorithms. RESULTS: Of the 740 practising GPs in Nova Scotia, 188 completed the questionnaire, for a response rate of 25.4%. The corresponding figures for optometrists and ophthalmologists were 73.6% (53/72) and 43.5% (20/46) respectively. Most of all three types of clinicians practise in Halifax County. More than 80% of the optometrists and ophthalmologists were aware of the algorithms, but less than 50% of the GPs were aware of them. A large majority of respondents in all three groups (77% to 98%) indicated that they were comfortable using the diabetes and red eye algorithms as presented. INTERPRETATION: Ophthalmologists, optometrists and GPs indicated an understanding of and willingness to use the diabetes and red eye algorithms. However, they were not unanimous regarding the choice of implementation method. Therefore, six different strategies for implementing the vision care algorithms are currently being used and are described in the paper.