Glaucoma progression detection with frequency doubling technology (FDT) compared to standard automated perimetry (SAP) in the Groningen Longitudinal Glaucoma Study.

PURPOSE: To determine the usefulness of frequency doubling perimetry (FDT) for progression detection in glaucoma, compared to standard automated perimetry (SAP). METHODS: Data were used from 150 eyes of 150 glaucoma patients from the Groningen Longitudinal Glaucoma Study. After baseline, SAP was performed approximately yearly; FDT every other year. First and last visit had to contain both tests. Using linear regression, progression velocities were calculated for SAP (Humphrey Field Analyzer) mean deviation (MD) and FDT MD and the number of test locations with a total deviation probability below p < 0.01 (TD). Progression velocity tertiles were determined and eyes were classified as slowly, intermediately, or fast progressing for both techniques. Comparison between SAP and FDT classifications were made using a Mantel Haenszel chi-square test. Longitudinal signal-to-noise ratios (LSNRs) were calculated, per patient and per technique, defined as progression velocity divided by the standard deviation of the residuals. RESULTS: Mean (SD) follow-up was 6.4 (1.7) years; median (interquartile range [IQR]) baseline SAP MD -6.6 (-14.2 to -3.6) dB. On average 8.2 and 4.5 tests were performed for SAP and FDT, respectively. Median (IQR) MD slope was -0.16 (-0.46 to +0.02) dB/year for SAP and -0.05 (-0.39 to +0.17) dB/year for FDT. Mantel Haenszel chi-squares of SAP MD vs FDT MD and TD were 12.5 (p < 0.001) and 15.8 (p < 0.001), respectively. LSNRs for SAP MD (median -0.17 yr-1 ) were better than those for FDT MD (-0.04 yr-1 ; p = 0.010). CONCLUSIONS: FDT may be a useful technique for monitoring glaucoma progression in patients who cannot perform SAP reliably.

Factors that influence standard automated perimetry test results in glaucoma: test reliability, technician experience, time of day, and season.

PURPOSE: To determine the influence of several factors on standard automated perimetry test results in glaucoma. METHODS: Longitudinal Humphrey field analyzer 30-2 Swedish interactive threshold algorithm data from 160 eyes of 160 glaucoma patients were used. The influence of technician experience, time of day, and season on the mean deviation (MD) was determined by performing linear regression analysis of MD against time on a series of visual fields and subsequently performing a multiple linear regression analysis with the MD residuals as dependent variable and the factors mentioned above as independent variables. Analyses were performed with and without adjustment for the test reliability (fixation losses and false-positive and false-negative answers) and with and without stratification according to disease stage (baseline MD). RESULTS: Mean follow-up was 9.4 years, with on average 10.8 tests per patient. Technician experience, time of day, and season were associated with the MD. Approximately 0.2 dB lower MD values were found for inexperienced technicians (P < 0.001), tests performed after lunch (P < 0.001), and tests performed in the summer or autumn (P < 0.001). The effects of time of day and season appeared to depend on disease stage. Independent of these effects, the percentage of false-positive answers strongly influenced the MD with a 1 dB increase in MD per 10% increase in false-positive answers. CONCLUSIONS: Technician experience, time of day, season, and the percentage of false-positive answers have a significant influence on the MD of standard automated perimetry.

Persistence, spatial distribution and implications for progression detection of blind parts of the visual field in glaucoma: a clinical cohort study.

BACKGROUND: Visual field testing is an essential part of glaucoma care. It is hampered by variability related to the disease itself, response errors and fatigue. In glaucoma, blind parts of the visual field contribute to the diagnosis but--once established--not to progression detection; they only increase testing time. The aims of this study were to describe the persistence and spatial distribution of blind test locations in standard automated perimetry in glaucoma and to explore how the omission of presumed blind test locations would affect progression detection. METHODOLOGY/PRINCIPAL FINDINGS: Data from 221 eyes of 221 patients from a cohort study with the Humphrey Field Analyzer with 30-2 grid were used. Patients were stratified according to baseline mean deviation (MD) in six strata of 5 dB width each. For one, two, three and four consecutive <0 dB sensitivities in the same test location in a series of baseline tests, the median probabilities to observe <0 dB again in the concerning test location in a follow-up test were 76, 86, 88 and 90%, respectively. For <10 dB, the probabilities were 88, 95, 97 and 98%, respectively. Median (interquartile range) percentages of test locations with three consecutive <0 dB sensitivities were 0(0-0), 0(0-2), 4(0-9), 17(8-27), 27(20-40) and 60(50-70)% for the six MD strata. Similar percentages were found for a subset of test locations within 10 degree eccentricity (P>0.1 for all strata). Omitting test locations with three consecutive <0 dB sensitivities at baseline did not affect the performance of the MD-based Nonparametric Progression Analysis progression detection algorithm. CONCLUSIONS/SIGNIFICANCE: Test locations that have been shown to be reproducibly blind tend to display a reasonable blindness persistence and do no longer contribute to progression detection. There is no clinically useful universal MD cut-off value beyond which testing can be limited to 10 degree eccentricity.

Risk factors for visual field progression in the groningen longitudinal glaucoma study: a comparison of different statistical approaches.

PURPOSE: To identify risk factors for visual field progression in glaucoma and to compare different statistical approaches with this risk factor analysis. PATIENTS AND METHODS: We included 221 eyes of 221 patients. Progression was analyzed using Nonparametric Progression Analysis applied to Humphrey Field Analyzer data. Risk factors were analyzed using the statistical approaches from the Advanced Glaucoma Intervention Study, the Early Manifest Glaucoma Trial, and the Canadian Glaucoma Study. Four intraocular pressure (IOP) variables (baseline IOP, mean IOP during follow-up, IOP fluctuation, and pretreatment IOP) and 8 other risk factors were investigated. RESULTS: On average, 7.1 reliable fields were available after a mean follow-up of 5.3 years; 89 eyes progressed. With the Advanced Glaucoma Intervention Study approach, age [odds ratio (OR) 1.03/y; 95% confidence interval (CI), 1.00-1.06; P = 0.044] predicted progression. With an additional stepwise selection procedure, mean IOP during follow-up (1.16 per mm Hg; 1.05-1.29; P=0.003),baseline HFA mean deviation (MD; 2.72 for worse versus better than --6 dB; 1.50-4.95; P=0.001) and age (1.03; 1.01-1.06;P=0.010) predicted progression [corrected]. With the Early Manifest Glaucoma Trial approach, baseline IOP [hazard ratio (HR) 1.07; 95% CI, 1.02-1.11; P = 0.010], baseline Frequency Doubling Perimeter MD (HR = 1.75; 95% CI, 1.14-2.70; P = 0.013), and age (HR = 1.03; 95% CI, 1.01-1.05; P = 0.006) predicted progression. Finally, with the Canadian Glaucoma Study approach, baseline IOP (HR = 1.07; 95% CI, 1.02-1.11; P = 0.010), baseline Frequency Doubling Perimeter MD (HR = 1.75; 95% CI, 1.14-2.70; P = 0.013), and age (HR = 1.03; 95% CI, 1.01-1.05; P = 0.006) predicted progression. CONCLUSIONS: IOP, disease stage, and age seemed to be robust independent risk factors for visual field progression in glaucoma. The IOP variable that was significant depended on the statistical approach applied.

[Infectious endophthalmitis after cataract extraction, a serious complication]. / Infectieuze endoftalmitis na cataractextractie: een ernstige complicatie.

Cataract extraction with lens implantation is the most used surgical procedure worldwide and is relatively safe. Nevertheless, this procedure carries the risk for infectious complications, since a foreign body is implanted in the eye to which bacteria that may cause endophthalmitis can adhere. Acute postoperative endophthalmitis is a potentially devastating disease that prompts immediate recognition and therapy, whereas chronic postoperative endophthalmitis is a low virulent, long-lasting infection that is hard to diagnose and for which the choice of treatment should be weighed carefully. We present 2 cases that illustrate both types of endophthalmitis. Before the decision to perform a cataract extraction is taken, the risk of infectious complications has to be considered in the light of the expected visual acuity gained by the procedure.

Glaucoma monitoring in a clinical setting: glaucoma progression analysis vs nonparametric progression analysis in the Groningen Longitudinal Glaucoma Study.

OBJECTIVE: To compare prospectively 2 perimetric progression detection algorithms for glaucoma, the Early Manifest Glaucoma Trial algorithm (glaucoma progression analysis [GPA]) and a nonparametric algorithm applied to the mean deviation (MD) (nonparametric progression analysis [NPA]). METHODS: Patients with a reproducible glaucomatous visual field defect at baseline in at least 1 eye were followed up prospectively using perimetry (Humphrey field analyzer 30-2 Swedish interactive thresholding algorithm). Classifications by GPA and by NPA at the end of the follow-up period were compared. RESULTS: Two hundred twenty-one patients met the inclusion criteria; 1 eye per patient was analyzed. On average, 7.1 reliable fields were available after a mean follow-up period of 5.3 years. The mean MD at baseline was -9.4 dB; the mean MD slope during the follow-up period was -0.25 dB/y. Fifty-six eyes showed progression by GPA and 89 eyes by NPA (P < .001); 42 eyes showed progression by both techniques (kappa = 0.39). In eyes with progression detected by NPA only, baseline MD was worse than that in eyes with progression detected by GPA (-12.5 vs -8.2 dB, P = .002), and GPA more often gave a reading of "baseline MD out of range" (P < .001). After exclusion of eyes with baseline MD out of range, the measure of agreement was kappa = 0.50. CONCLUSIONS: Nonparametric progression analysis had fairly good agreement with GPA. Especially in cases of more advanced disease, NPA labeled more eyes as having progression than GPA.