Yes / Purpose: We have developed customized maps that relate visual field and optic nerve head (ONH) regions according to individual anatomy. In this study, we aimed to determine feasible map resolution for research use, and to make a principled recommendation of sector size for clinical applications. Methods: Measurement variability in fovea–ONH distance and angle was estimated from 10 repeat OCT scans of 10 healthy people. Errors in estimating axial length from refractive error were determined from published data. Structure–function maps were generated, and customized to varied clinically-plausible anatomical parameters. For each parameter set (n = 210), 200 maps were generated by sampling from measurement/estimation error distributions. Mapped 1° sectors at each visual field location from each parameter set were normalized to difference from their mean. Variation (90% ranges) in normalized mapped sectors represents the precision of individualized maps. Results: Standard deviations of repeated measures of fovea–ONH distance and angle were 61 μm and 0.97° (coefficients of variation 1.3% and 12.0%, respectively). Neither measure varied systematically with mean (Spearmans's ρ = 0.26, P = 0.47 for distance, ρ = −0.31, P = 0.39 for angle). Variation (90% ranges) in normalized mapped sectors varied across the visual field and ranged from 3° to 18° when axial length was measured accurately, and from 6° to 32° when axial length was estimated from refractive error. Conclusions: The 90% ranges represent the minimum feasible ONH sector size at each visual field location. For clinical use an easily interpretable scheme of 30° sectors is suggested.

No / This study aimed to determine if response times gathered during perimetry can be exploited within a thresholding algorithm to improve the speed and accuracy of the test. Frequency of seeing (FoS) curves were measured at 24 locations across the central 30° of the visual field of 10 subjects using a Method of Constant Stimuli, with response times recorded for each presentation. Spatial locations were interleaved, and built up over multiple 5-min blocks, in order to mimic the attentional conditions of clinical perimetry. FoS curves were fitted to each participant’s data for each location, and response times derived as a function of distance-from-threshold normalised to the slope of each FoS curve. This data was then used to derive a function for the probability of observing response times given the distance-from-threshold, and to seed simulations of a new test procedure (BURTO) that exploited the probability function for stimulus placement. Test time and error were then simulated for patients with various false response rates. When compared with a ZEST algorithm, simulations revealed that BURTO was about one presentation per location faster than ZEST, on average, while sacrificing less precision and bias in threshold estimates than simply terminating the ZEST earlier. Despite response times varying considerably for a given individual and their thresholds, response times can be exploited to reduce the number of presentations required in a visual field test without loss of accuracy.

Yes / PURPOSE. To compare microperimetric sensitivity around the monocular preferred retinal locus (mPRL) in age-related macular degeneration (AMD) to normative data, and to describe the characteristics of visual field defects around the mPRL in AMD. METHODS. Participants with AMD (total n ¼ 185) were either prospectively recruited (n ¼ 135) or retrospectively reviewed from an existing database (n ¼ 50). Participants underwent microperimetry using a test pattern (37 point, 58 radius) centered on their mPRL. Sensitivities were compared to normative data by spatial interpolation, and conventional perimetric indices were calculated. The location of the mPRL relative to the fovea and to visual field defects was also investigated. RESULTS. Location of mPRL varied approximately 158 horizontally and vertically. Visual field loss within 58 of the mPRL was considerable in the majority of participants (median mean deviation 14.7 dB, interquartile range [IQR] 19.6 to 9.6 dB, median pattern standard deviation 7.1 dB [IQR 4.8–9.0 dB]). Over 95% of participants had mean total deviation worse than 2 dB across all tested locations and similarly within 18 of their mPRL. A common pattern of placing the mPRL just foveal to a region of normal pattern deviation was found in 78% of participants. Total deviation was outside normal limits in this region in 68%. CONCLUSIONS. Despite altering fixation to improve vision, people with AMD exhibit considerable visual field loss at and around their mPRL. The location of the mPRL was typically just foveal to, but not within, a region of relatively normal sensitivity for the individual, suggesting that a combination of factors drives mPRL selection. / This report presents independent research funded by the NIHR

Yes / Purpose: Frequency-of-seeing (FoS) curves (psychometric functions) for perimetric stimuli have been widely used in computer simulations of new visual field test procedures. FoS curves for age-related macular degeneration (AMD) are not available in the literature and are needed for the development of improved microperimetry test procedures, which are of particular interest for use as clinical trial endpoints. Methods: Data were refitted from a previous study to generate FoS curves for 20 participants with AMD, each tested at nine locations within the central 10°. Stimulus parameters, background luminance and dB scale were matched to the MAIA-2 microperimeter, and stimuli were presented in a method of constant stimuli to build up FoS curves over multiple runs. FoS curves were fitted with a modified cumulative Gaussian function. The relationship between sensitivity and slope of fitted FoS curves was modelled by robust linear regression, producing models both with and without an eccentricity parameter. Results: FoS curves were satisfactorily fitted to data from 174 visual field locations in 20 participants (age 65–83 years, 11 female). Each curve was made up of a median of 243 (range 177–297) stimulus presentations over a median of 12 (range 9–32) levels. Median sensitivity was 25.5dB (range 3.8–31.4dB). The median slope (SD of fitted function) was 1.6dB (range 0.5–8.5dB). As in previous studies of other conditions, the slope of fitted FoS curves increased as sensitivity decreased (p<0.001). Conclusions: FoS are provided for participants with AMD, as well as models of the relationship between sensitivity and slope. These fitted models and data may be useful for computer simulation studies of microperimetry procedures. Full details of the fitted curves are provided as supporting information.

Yes / Microperimetry, also referred to as fundus perimetry or fundus-driven perimetry, enables simultaneous acquisition of visual sensitivity and eye movement data. We present sensitivity data collected from 60 participants with normal vision using gaze-contingent perimetry. A custom designed spatially dense test grid was used to collect data across the visual field within 13° of fixation. These data are supplemental to a study in which we demonstrated a spatial interpolation method that facilitates comparison of acquired data from any set of spatial locations to normative data and thus screening of individuals with both normal and non-foveal fixation (Denniss and Astle, 2016)[1].

No description available.

Synfältsundersökningen är den viktigaste metoden för att diagnostisera och identifiera progression av glaukom. Att genomföra synfältsundersökningen är en vanligt förekommande arbetsuppgift för ögonsjuksköterskan. Studier visar att patienter har svårigheter vid genomförandet av undersökningen, men studier på hur patienten själv upplever synfältsundersökningstillfället saknas. Syftet med pilotstudien var att undersöka patientens upplevelse av synfältsundersökningstillfället. Pilotstudien genomfördes med en kvalitativ metod och data samlades in genom semistrukturerade intervjuer av åtta patienter. Materialet analyserades med hjälp av kvalitativ innehållsanalys. Analysen ledde till fem kategorier: upplevelse av rädsla och oro, svårt med fokusering, upplevelse av information, känsla av trygghet, och kroppsligt obehag. Att inte prestera bra och att eventuellt blivit försämrad i sjukdomen var det som främst skapade rädsla och oro. Fokusering krävde mycket koncentration och var ansträngande för ögonen. Informationen upplevdes som både bra och bristfällig. Patienterna kände en trygghet då de hade gjort undersökningen tidigare och att de träffade samma personal. Majoriteten av patienterna upplevde att de satt obekvämt och inte patientvänligt. Fortsatt utveckling och utbildning om hur patienter upplever synfältsundersökningstillfället rekommenderas för att förbättra hur personalen bemöter och informerar patienten, men även för hur ögonsjuksköterskan kan underlätta undersökningen för patienten. Då denna studie utfördes som en pilotstudie behövs vidare forskning och en fullskalig studie för att resultatet ska kunna anses vara tillförlitligt. / Visual field examination is the most important method to diagnose and identify the progression of glaucoma. Conducting visual field examination is a common task for the ophthalmic nurse. Studies show that patients have difficulty in carrying out the visual field examination, but studies on how the patient experiences the visual field examination are scarce. The aim of the pilot study was to examine the patient's experience of the visual field examination. The pilot study was conducted using a qualitative approach and data was collected through semi-structured interviews of eight patients. The material was analyzed using content analysis. The analysis resulted in five categories: experience of fear and anxiety, difficulty with focusing, experience of information, sense of security, and bodily discomfort. Failing to perform well and to possibly become impaired in their disease were major concerns that created fear and anxiety. Focusing demanded a lot of concentration and was straining on the eye. The information was perceived as both good and flawed. Patients felt a sense of security since they had done the examination before and that they met the same staff. The majority of patients felt they sat uncomfortably and that it was not patient friendly. Continued development and training on how patients experience visual field examination is recommended to improve the way the staff treats and informs the patient, but also how the ophthalmic nurse can facilitate the examination of the patient. Since this study was conducted as a pilot study further research and a full-scale study is needed for the results to be considered reliable.

Licentiatavhandling (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 2 uppsatser.

Yes / Purpose: To demonstrate methods that enable visual field sensitivities to be compared with normative data without restriction to a fixed test pattern. Methods: Healthy participants (n = 60, age 19–50) undertook microperimetry (MAIA-2) using 237 spatially dense locations up to 13° eccentricity. Surfaces were fit to the mean, variance, and 5th percentile sensitivities. Goodness-of-fit was assessed by refitting the surfaces 1000 times to the dataset and comparing estimated and measured sensitivities at 50 randomly excluded locations. A leave-one-out method was used to compare individual data with the 5th percentile surface. We also considered cases with unknown fovea location by adding error sampled from the distribution of relative fovea–optic disc positions to the test locations and comparing shifted data to the fixed surface. Results: Root mean square (RMS) difference between estimated and measured sensitivities were less than 0.5 dB and less than 1.0 dB for the mean and 5th percentile surfaces, respectively. Root mean square differences were greater for the variance surface, median 1.4 dB, range 0.8 to 2.7 dB. Across all participants 3.9% (interquartile range, 1.8–8.9%) of sensitivities fell beneath the 5th percentile surface, close to the expected 5%. Positional error added to the test grid altered the number of locations falling beneath the 5th percentile surface by less than 1.3% in 95% of participants. Conclusions: Spatial interpolation of normative data enables comparison of sensitivity measurements from varied visual field locations. Conventional indices and probability maps familiar from standard automated perimetry can be produced. These methods may enhance the clinical use of microperimetry, especially in cases of nonfoveal fixation.

Yes / Purpose Perimetry is increasingly being used to measure sensitivity at central visual field locations. For many tasks, the central (0°, 0°) location is functionally the most important, however threshold estimates at this location may be affected by masking by the nearby spatial structure of the fixation target. We investigated this effect. Methods First we retrospectively analysed microperimetry (MAIA-2; CenterVue, Padova, Italy) data from 60 healthy subjects, tested on a custom grid with 1° central spacing. We compared sensitivity at (0°, 0°) to the mean sensitivity at the eight adjacent locations. We then prospectively tested 15 further healthy subjects on the same instrument using a cross-shaped test pattern with 1° spacing. Testing was carried out with and without the central fixation target, and sensitivity estimates at (0°, 0°) were compared. We also compared sensitivity at (0°, 0°) to the mean of the adjacent four locations in each condition. Three subjects undertook 10 repeated tests with the fixation target in place to assess within-subject variability of the effect. Results In the retrospective analysis, central sensitivity was median 2.8 dB lower (95% range 0.1–8.8 dB lower, p < 0.0001) than the mean of the adjacent locations. In the prospective study, central sensitivity was median 2.0 dB lower with the fixation target vs without (95% range 0.4–4.7 dB lower, p = 0.0011). With the fixation target in place central sensitivity was median 2.5 dB lower than mean sensitivity of adjacent locations (95% range 0.8–4.2 dB lower, p = 0.0007), whilst without the fixation target there was no difference (mean 0.4 dB lower, S.D. 0.9 dB, p = 0.15). These differences could not be explained by reduced fixation stability. Mean within subject standard deviation in the difference between central and adjacent locations' sensitivity was 1.84 dB for the repeated tests. Conclusions Perimetric sensitivity estimates from the central (0°, 0°) location are, on-average, reduced by 2 to 3 dB, corresponding to a 60–100% increase in stimulus luminance at threshold. This effect can be explained by masking by the nearby fixation target. The considerable within- and between-subject variability in magnitude, and the unknown effects of disease may hamper attempts to compensate threshold estimates for this effect. Clinicians should interpret central perimetric sensitivity estimates with caution, especially in patients with reduced sensitivity due to disease.