How Do Patients Feel About Visual Field Testing? Analysis of Subjective Perception of Standard Automated Perimetry.

PURPOSE: A high rate of unreliability is an issue in visual field (VF) testing, especially in elderly patients, and warrants patient education. We assessed whether subjective perception of the visual field test (VFT) is a good predictor of its reliability in different age groups and examined age differences in patients' awareness of VF damage. METHODS: This cross-sectional study investigated 107 VFT results of 54 patients with glaucoma or ocular hypertension. Subjective perceptions were compared to reliability indices for cooperation analysis and to mean deviation results for VF damage analysis, and an age-segregated sub-analysis was performed. RESULTS: Kappa coefficients showed poor agreement between subjective and objective parameters. Nevertheless, there were age differences. Younger patients had a higher positive predictive value and sensitivity in cooperation analysis and a higher negative predictive value in VF damage analysis. CONCLUSIONS: Patients' perception of cooperation in VFT is a poor predictor of its reliability. Although young cooperative patients may be aware of their good cooperation, even the youngest are unaware of their poor performance. This emphasizes the importance of giving proper directions to all patients during VFT to obtain better reliability indices. Younger, healthy patients are more aware of their health status, than those with a damaged VF, regardless of age. Therefore, illness education is crucial in all glaucoma patients.

Anxiety in visual field testing.

BACKGROUND: To determine if Humphrey visual field (HVF) testing induces anxiety and how anxiety relates to visual field parameters of reliability and severity. DESIGN: A prospective cohort study at a university affiliated private ophthalmic practice. PARTICIPANTS: 137 consecutive age-matched and gender-matched patients with glaucoma undergoing either HVF testing only (n=102) or Heidelberg retinal tomography (HRT) only (n=35) were enrolled. METHODS: Prior to testing, participants completed the State-Trait Anxiety Inventory questionnaire. A 5-point Likert scale was used to grade pretest anxiety and was repeated after testing to grade intratest anxiety. Subjective discomfort parameters were also recorded. MAIN OUTCOME MEASURES: Anxiety scores were used to make non-parametrical comparisons and correlations between cohorts and also against visual field reliability and severity indices. RESULTS: Trait anxiety (p=0.838) and pretest anxiety (p=0.802) were not significantly different between test groups. Within the HVF group, intratest anxiety was 1.2 times higher than pretest anxiety (p=0.0001), but was not significantly different in the HRT group (p=0.145). Pretest anxiety was correlated with test unreliability (Spearman's r=0.273, p=0.006), which was predictive of worse test severity (p=0.0027). Subjects who had undergone more than 10 visual field tests had significantly lower pretest and intratest anxiety levels than those who had not (p=0.0030 and p=0.0004, respectively). CONCLUSIONS: HVF testing induces more anxiety than HRT. Increased pretest anxiety may reduce HVF test reliability. Increased test experience or interventions aimed at reducing pretest anxiety may result in improved test reliability and accuracy.

The influence of the learning effect on automated perimetry in a Turkish population.

PURPOSE: To evaluate the influence of learning effect on the outcome of automated perimetry and to assess the factors associated with the learning effect in a Turkish population. METHODS: The Swedish Interactive Threshold Algorithm (SITA) standard 30-2 test was performed on a Humphrey Visual Field Analyzer in 102 normal Turkish subjects who had not previously undertaken any form of perimetry. Each subject completed three testing sessions, each separated by at least one day. The SITA standard 30-2 testing sessions included both eyes. The right eye was always tested before left eye. The reliability parameters, test duration and visual field (VF) global indices (mean deviation [MD] and pattern standard deviation [PSD]) obtained from right eyes in the first and third sessions were compared to assess the learning effect. Change in these parameters between the first and third sessions was calculated, and the effect of gender, age and educational level on this change was evaluated. RESULTS: The reliability parameters, test duration and VF global indices each improved between the first and third sessions (P ≤ 0.001). The change in the parameters was greater in subjects over 50 years of age and with an educational level less than high school (P ≤ 0.01). No correlation was found between learning effect and gender. CONCLUSION: In normal Turkish subjects, a significant learning effect was observed during VF testing with the SITA standard 30-2. The learning effect was correlated with age and educational level.

A qualitative investigation into patients' views on visual field testing for glaucoma monitoring.

OBJECTIVES: To investigate the views and experiences of patients regarding their glaucoma follow-up, particularly towards the type and frequency of visual field (VF) testing. DESIGN: A qualitative investigation using focus groups. The group discussion used broad open questions around the topics in a prompt guide relating to experiences of glaucoma follow-up, and in particular, VF monitoring. All the groups were taped, transcribed and coded using manual and computer-aided methods. SETTING: Three National Health Service (NHS) hospitals in England; two focus groups took place at each hospital. PARTICIPANTS: 28 patients (mean (SD) age: 74 (9) years; 54% women) diagnosed with glaucoma for at least 2 years. Each focus group consisted of 3-6 patients. PRIMARY AND SECONDARY OUTCOMES: (1) Attitudes and experiences of patients with glaucoma regarding VF testing. (2) Patients' opinions about successful follow-up in glaucoma. RESULTS: These patients did not enjoy the VF test but they recognised the importance of regular monitoring for preserving their vision. These patients would agree to more frequent VF testing on their clinician's recommendation. A number of themes recurred throughout the focus groups representing perceived barriers to follow-up care. The testing environment, waiting times, efficiency of appointment booking and travel to the clinic were all perceived to influence the general clinical experience and the quality of assessment data. Patients were also concerned about aspects of patient-doctor communication, and often received little to no feedback about their results. CONCLUSIONS: Patients trust the clinician to make the best decisions for their glaucoma follow-up. However, patients highlighted a number of issues that could compromise the effectiveness of VF testing. Addressing patient-perceived barriers could be an important step for devising optimal strategies for follow-up care.

Lateral vision in horses: a behavioral investigation.

This study investigated lateral vision in horses (Equus caballus) for the first time from a behavioral point of view. Three horses were tested using a novel experimental design to determine the range of their lateral and caudolateral vision with respect to stimulus detection and discrimination. Real-life stimuli were presented along a curvilinear wall in one of four different positions (A, B, C, D) and one of two height locations (Top, Bottom) on both sides of the horse. To test for stimulus detection, the correct stimulus was paired against a control; for stimulus discrimination, the correct stimulus was paired against another object. To indicate that the correct stimulus was detected or discriminated, the horses pushed one of two paddles. All horses scored significantly above chance on stimulus detection trials regardless of stimulus position or location. They also accurately discriminated between stimuli when objects appeared in positions A, B, and C for the top or bottom locations; however, they failed to discriminate these stimuli at position D. This study supports physiological descriptions of the equine eye and provides new behavioral data showing that horses can detect the appearance of objects within an almost fully encompassing circle and are able to identify objects within most but not all of their panoramic field of view.

[Does music influence visual perception in campimetric measurements of the visual field?]. / Beeinflusst Musik die visuelle Wahrnehmung in der kampimetrischen Gesichtsfeldprüfung?

21 subjects (mean age 28,4 +/- 10,9, M +/- SD) without any damage of the visual system were examined with computer-based campimetric tests of near threshold stimulus detection whereby an artificial tunnel vision was induced. Campimetry was performed in four trials in randomized order using a within-subjects-design: 1. classical music, 2. Techno music, 3. music for relaxation and 4. no music. Results were slightly better in all music conditions. Performance was best when subjects were listening to Techno music. The average increase of correctly recognized stimuli and fixation controls amounted to 3 %. To check the stability of the effects 9 subjects were tested three times. A moderating influence of personality traits and habits of listening to music was tested but could not be found. We conclude that music has at least no negative influence on performance in the campimetric measurement. Reasons for the positive effects of music can be seen in a general increase of vigilance and a modulation of perceptual thresholds.

Learning effect of Humphrey Matrix perimetry.

BACKGROUND: Humphrey Matrix perimetry is a recent development in automated perimetry that uses frequency-doubling technology (FDT). We evaluated the learning effect of Humphrey Matrix perimetry with a full-threshold 30-2 strategy. METHODS: Twenty-four patients with primary open-angle glaucoma and early visual field defects as assessed by standard automated perimetry and 24 healthy control subjects participated. All subjects had no prior experience with FDT visual field tests. Humphrey Matrix perimetry using a full-threshold 30-2 strategy was performed 3 times within 1 month. Various visual field indices were compared across multiple tests. RESULTS: Mean deviation (MD) showed a larger defect at the first test than at the second and third tests (p < 0.001), and the mean total improvement of the MD was 2.80 decibels (dB) in the glaucoma group and 1.71 dB in the control group. Pattern standard deviations (PSDs) were decreased as the tests were repeated, but test duration, fixation losses, and false-positive or false-negative rate were not changed significantly. Additionally, the Glaucoma Hemifield Test (GHT) showed unstable results. INTERPRETATION: In patients naive to the FDT test, Humphrey Matrix perimetry showed a large learning effect on MD and PSD among the various visual field indices. The GHT results of Humphrey Matrix perimetry showed a large instability.

Learning effect, normal range, and test-retest variability of Frequency Doubling Perimetry as a function of age, perimetric experience, and the presence or absence of glaucoma.

The learning effect for several different Frequency Doubling Perimetry parameters was studied in full threshold mode in a large group of patients (n = 342) of various ages, with and without perimetric experience, and with and without glaucoma. A significant learning effect was only found for the mean deviation (MD) in aged normals without perimetric experience. The median of MD increased for both OD (from +0.2 to +1.0 dB) and for OS (from +0.5 to +1.3 dB). The effect disappeared largely during a third visit (median OD +1.2 dB, OS +1.3 dB). The normal range and the test-retest variability were measured in the same dataset. The learning effect for MD (1 dB or less) appeared to be small as compared with both the normal range (about 12 dB) and the test-retest variability (about 3 dB).

[Visual field examination in limited patient cooperation]. / Gesichtsfeldprüfung bei eingeschränkter Kooperation.

Objective methods to estimate the visual field are necessary, if a conventional subjective perimetry is impossible due to limited cooperation. Objective methods are indicated in infants, handicapped patients, patients with psychogenic visual field loss, and malingerers. An objective estimation of the visual field can be performed by means of pupillary light reflexes, voluntary and involuntary eye movements, and visual evoked potentials. Systematically false responses contain useful information regarding the proof of misrepresentations. The reproducibility of visual field defects can be checked by testing at different distances from the screen. This article reports on handy methods requiring no large-scale equipment.

Changes of glaucomatous field defects. Degree of accuracy of measurements with the automatic perimeter Octopus.

The analytical programme Delta was used to determine longterm fluctuation and accuracy of measurement of the programme 31 of Octopus when used on glaucoma patients. Programme 31 examines the 30 degrees field. The test locations are arranged in a square grid with 6 degrees resolution. The programme Delta determines and compares 1) the disturbed area in %; 2) the total loss, the total sensitivity being around 2000 dB; 3) the loss in dB per mean number of disturbed points. Thirty-two eyes of 22 patients with established glaucomatous field defects were examined twice within two to six days and two months later again twice. The size of the disturbed area served for classification of our sample into three groups: 1st group: disturbed area 1-33%; 2nd group: disturbed area 34-66%; 3rd group: disturbed area 67-100%. Long-term fluctuations and accuracy of measurement could be determined as respectively follows: 1) Disturbed area between 0.7 +/- 8% in group 3 and 1.7 +/- 13% in group 2. 2) The total loss increases proportionately to the disturbed area and was 4.9 +/- 29.2 dB in group 1 and 31.8 +/- 82.4 dB in group 3. 3) The total loss per mean number of disturbed points was 0.5 +/- 2 dB in group 1 and 0.3 +/- 1.2 dB in group 2. This signifies that if the learning effect is over, changes of more than 2 dB, especially if several adjacent points are affected, are a significant loss. The learning effect, as determined in an earlier study, may go up as high as 2 dB per point.