My Papers by Paul H Artes
PURPOSE. Peripheral vision is important for mobility, balance, and guidance of attention, but sta... more PURPOSE. Peripheral vision is important for mobility, balance, and guidance of attention, but standard perimetry examines only <20% of the entire visual field. We report on the relation between central and peripheral visual field damage, and on retest variability, with a simple approach for automated kinetic perimetry (AKP) of the peripheral field.
I hate having to pay for my own stuff...
Vision by Paul H Artes
Letter to the Editor by Denis Pelli and John Robson, persuasively argues the merit of using lette... more Letter to the Editor by Denis Pelli and John Robson, persuasively argues the merit of using letter-like stimuli for clinical vision measurements.
Visual Fields by Paul H Artes
Henning Roenne, “Zur Theorie und Technik der Bjerrumschen Gesichtsfelduntersuchung.” Archiv für A... more Henning Roenne, “Zur Theorie und Technik der Bjerrumschen Gesichtsfelduntersuchung.” Archiv für Augenheilkunde, Bd. 78, Heft 4, 1915
Introductory text on Visual Fields, by Lyne Racette, Monika Fischer, Hans Bebie, Gábor Holló, Chr... more Introductory text on Visual Fields, by Lyne Racette, Monika Fischer, Hans Bebie, Gábor Holló, Chris A. Johnson, and Chota Matsumoto.
In the 'method of constant stimuli' a stimulus is presented a number of times at various luminanc... more In the 'method of constant stimuli' a stimulus is presented a number of times at various luminance levels and the subject is asked to react the moment he sees the stimulus. For a given stimulus value a percentage of positive reactions is obtained as compared with the total number of times the stimulus is presented.
We have devised a package for the statistical analysis of computerized visual fields. It is based... more We have devised a package for the statistical analysis of computerized visual fields. It is based on a new mathematical model of the normal visual field and intended to facilitate interpretation of single fields and to illustrate changes over time in consecutive threshold fields. Single field analyses include maps showing pointwise total and pattern deviations from the age-corrected normal reference field. These maps are displayed both numerically, in dB, and as noninterpolated greyscaled probability maps illustrating the statistical significance of measured deviations. These probability maps help emphasize shallow, but significant, depressions in the paracentral field while frequently occurring false positive deviations occurring in the midperiphery are de-emphasized. Visual field indices, summarizing the deviations of height (Mean Deviation) and shape (Pattern Standard Deviation and Corrected Pattern Standard Deviation) of the measured field are weighted according to the normal variance among healthy individuals and printed out together with level of statistical significance For follow-up the programme contains several different options. These range from an Overview format where threshold printouts and probability maps from several tests are printed in reduced size, but without any reduction of data, on a single sheet of paper, to a box plot format where the development of the field is shown with an intermediate degree of data reduction and a format employing a high degree of data reduction: graphs over visual field indices over time. If five or more tests are available a linear regression analysis of Mean Deviation is automatically performed. The programme will become available in the Humphrey Field Analyzer.
At the psychophysical section of the first Congress for Experimental Psychology held at Giessen A... more At the psychophysical section of the first Congress for Experimental Psychology held at Giessen April 18-21, 1904, F. Schumann reported what he termed an unusual case of ' color bhndness (his own).^So far as the ability to get the positive sensation is concerned, Dr. Schumann is, according to the report, totally blind to green and partially so to red.Î n addition his case presents the following features, (i) While green light does not arouse a sensation of green, it does give red after-image and contrast sensations. Red light on the other hand gives a positive sensation but does not give cither after-image or contrast sensations.^(2) A colorless mixed light can be matched by combining homogeneous red and green lights, but quite a little greater proportion of green is needed to give the neutral sensation than is required for 1 Schumann, F., 'Ein ungewohnlicher Fall von Farbenbllndheit,' Bericht iiber den I. Kongress fiir experimentelle Psychologie in Giessen, 1904, pp. 10-13. See also G. E. Mullet's discussion of the report, ibid., pp. 20-21.
By Dersu, Wiggins, Luther, Harper, Chacko. Brief but useful and practical article on Goldmann per... more By Dersu, Wiggins, Luther, Harper, Chacko. Brief but useful and practical article on Goldmann perimetry.
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My Papers by Paul H Artes
Vision by Paul H Artes
Visual Fields by Paul H Artes
of people made important specific contributions to the Primer.
For their generous help in our search for illustrative case histories we are indebted to: Yvonne AIden; Roy W Beck, MD; John A. Fleishman, MD; S. Samuel Gelban, MD; Roger Gimbell, COA; the
Glendale Eye Medical Group; George R. Hurd; Marc F. Lieberman , MD; Christian Mageli, COA; V Michael Patel; Steven B. Perlmutter, MD; Linda Sexton, COT; and Scott O. WiIsum . Additional
heartfelt thanks go to John A. Fleishman, MD and S. Samuel Gelbart, MD for their aid and advice on the preparation of sections on specific types of field defects.
Thomas W Raasch, OD, was a great help with background research.
Allergan Humphrey staff members who deserve special thanks include V Michael Patella, Allergan Humphrey's Director or Clinical Research, whose guidance and patience were indispensible; Chris Ritter, Marketing Director, who got the project started; and Mee Mee Wong, Product Manager in charge or the Field Analyzer, whose dedicated attention to countless details made it possible for the project to finish. Other Allergan Humphrey smIT members who contributed were Jackie Chadwick and Ed Buliavac.
Preparation of the Primer has been in the general charge of Mary Jean Haley, who wrote: Much of the text and edited all of it. The Allergan Corporation contributed invaluable financial support to this project.
Analyzer« beruht auf der von der Firma Allergan Humphrey herausgegebenen zweiten Auflage des »FieldAnalyzer Primer« aus dem Jahre 1987. In neueren Softwarefreigaben Sind einige Formulierungen überarbeitet worden, so daß sie nicht mehr mit denen älterer deutscher Bedienungsanleitungen identisch sind. So entspricht z.B. in diesem Leitfaden der Begriff »Standard«-Strategie dem früheren »Beginnhelligkeitautomatisch«.
Die zur Erläuterung im englischen Original gewählten Fallbeispiele
wurden beibehalten. Die Abbildungen, die die Ausdrucke des »Field Analyzers« zeigen, sind in ihrer englischen Form übernommen worden, die Bildunterschriften wurden aber ins Deutsche übersetzt. Bei den im deutschen Sprachraum ausgelieferten Geräten der Firma Allergan Humphrey erscheinen nicht nur auf den Bildschirmen der Perimeter, sondern auch auf den Ausdrucken die Begriffe in deutscher Sprache. Im Anhang sind deshalb einige Muster der deutschsprachigen Ausdrucke
wiedergegeben. Zusammen mit den entsprechenden Abschnitten in den deutschsprachigen Bedienungsanleitungen sollte es stets möglich sein, ein hier auf Englisch wiedergegebenes Bild eines Perimetrieergebnisses richtig zu interpretieren. Dabei ist es sehr hilfreich, daß die Anordnung der Begriffe auf den Ausdrucken im Deutschen wie im Englischen völlig übereinstimmt. Man findet also die gewünschten Ergebnisse in beiden Sprachen jeweils an der gleichen Stelle auf dem Ausdruck.
eye disease that affects 2 in 100 people older than
40y. It can lead to blindness. Most cases are detected
by optometrists during routine eye examinations.
It has been suggested that, in the UK, one in five
patients with glaucoma already have advanced
damage when they first present for treatment.1
Methods: We audited clinical correspondence to
identify all patients who had been newly diagnosed
with open-angle glaucoma during the 6-months
period from December ’14 to May ’15, at the West
of England Eye Unit of the Royal Devon & Exeter
Hospital. Corresponding visual fields were retrieved
from the units’ Humphrey Field Analyzers.
Results: During the audit period, 605 new patients
were examined, and 327 patients were diagnosed
with open-angle glaucoma, narrow-angle glaucoma,
or a high-risk of developing glaucoma. Seventy-one
patients were newly diagnosed with open-angle
glaucoma (OAG). In these patients, the visual field
Mean Deviation (MD) of the worse eye ranged from
−23 dB (clinically blind) to +3 dB (median, −3.4 dB).
Seven patients (10% of the newly diagnosed OAGs;
median age, 81 years) first presented with severe
damage (MD < −12 dB in the more damaged eye).
Conclusions One in 10 patients with open-angle
glaucoma presented with advanced damage.
Though smaller than suggested elsewhere, this group
of patients presents an important public-health
opportunity for interventions to reduce avoidable
blindness from glaucoma.
Reference: Boodhna & Crabb. Disease severity in newly
diagnosed glaucoma patients. Ophth Physiol Opt 2015.
Objective To test the hypothesis that frequency-doubling matrix perimetry (FDT2) is more sensitive than standard automated perimetry (SAP) in identifying visual field progression in glaucoma.
Design, Setting, and Participants Patients with open-angle glaucoma and healthy controls were examined by FDT2 and SAP, both with the 24-2 test pattern, on the same day at 6-month intervals in a longitudinal prospective study conducted in a hospital-based setting. Only participants with at least 5 examinations were included.
Intervention Data were analyzed with permutation of pointwise linear regression.
Main Outcome and Measure Permutation of pointwise linear regression is individualized to each participant, in contrast to current analyses in which the statistical significance is inferred from population-based approaches. Analyses were performed with both total deviation and pattern deviation.
Results Sixty-four patients and 36 controls were included in the study. The median age, SAP mean deviation, and follow-up period were 65 years, −2.6 dB, and 5.4 years, respectively, in patients and 62 years, +0.4 dB, and 5.2 years, respectively, in controls. Using total deviation analyses, statistically significant deterioration was identified in 17% of patients with FDT2, in 34% of patients with SAP, and in 14% of patients with both techniques; in controls these percentages were 8% with FDT2, 31% with SAP, and 8% with both. Using pattern deviation analyses, statistically significant deterioration was identified in 16% of patients with FDT2, in 17% of patients with SAP, and in 3% of patients with both techniques; in controls these values were 3% with FDT2 and none with SAP.
Conclusions and Relevance No evidence was found that FDT2 is more sensitive than SAP in identifying visual field deterioration. In about one-third of healthy controls, age-related deterioration with SAP reached statistical significance.
Methods: Participants were patients with open-angle glaucoma and visual field mean deviation worse than -20 dB on programme 24-2 of the Humphrey Visual Field Analyzer (SITA Standard), in one or both eyes. Inclusion criteria were: (1) BCVA ≤ +0.3 logMAR, (2) refractive error within ±6.0 DS and ±3.0 DC and pseudophakia from uncomplicated cataract surgery with implantation of a monofocal posterior chamber IOL, or transparent lens according to the Lens Opacities Classification System III (LOCS III). Exclusion criteria were: (1) non-glaucomatous ocular disease, (2) systemic disease and/or medications known to affect the visual field and/or contrast sensitivity, or the ability to participate in the study, and (3) previous ocular surgeries other than refractive, cataract or glaucoma surgeries. All participants underwent CS testing with the Pelli-Robson chart (PR, Precision Vision, IL, USA; distance, 1m) and the Freiburg Visual Acuity and Contrast Test (FrACT, http://michaelbach.de/fract/, version 3.9.3; distance, 1.60 m). Retest data were obtained 7 to 30 days after the initial measurements.
Results: Seventeen patients (median age, 68 years; range, 45 to 100 years) were included. Demographics and clinical characteristics are given in Table 1. Visual acuity explained less than 50% of the variance in contrast sensitivity. CS estimates of both tests were closely related (Spearman rank correlation coefficient, 0.8), but CS was 0.08 log units higher with FrACT (median; 95% CI, 0.02 to 0.16 log) than with the PR chart. Bland-Altman 95% repeatability intervals appeared slightly tighter with the PR chart.
Conclusions: Despite near-normal visual acuity, almost all patients showed moderate or profound deficits in contrast sensitivity (>2-fold elevation of thresholds from the normal value of ~1.70 log). Contrast sensitivity may add clinically valuable information on foveal visual function in patients with advanced glaucoma, beyond that available from standard visual acuity.
1 Eye and Vision Research group, Plymouth University, UK
2 Carl Zeiss AG, Feldbach ZH, CH
3 NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
Are big stimuli “easier” to see? An analysis of response times from frequency-of-seeing data.
Purpose: Patients have commented that visual field tests with larger stimuli are easier to perform. We investigated if response times (RTs) provide objective evidence for this – on the premise that more certain responses have shorter and/or less variable latencies.
Methods: We analysed data from frequency-of-seeing (FOS) experiments on 20 healthy controls and 7 patients with glaucoma. FOS data were obtained at 5 central and 5 peripheral locations, up to 85° from fixation. At each location, 10 stimuli were presented, in random order, at each of 8 intensities (800 stimuli per experiment). Stimulus sizes III (0.43°) and V (1.70°) were used during separate sessions. Experiments were performed on an Octopus 900 perimeter controlled through the Open Perimetry Interface. The variability of response latencies from individual observers was expressed as the interquartile range (IQR), after stratifying responses into “near-threshold” (within ±3 dB of FOS threshold) and “highly visible” (>10 dB brighter than FOS threshold) categories.
Results: For stimuli within 3 dB of threshold, RT distributions with size III and size V stimuli were nearly identical, both in average as well as variability (Table 1). For highly visible stimuli (>10 dB above threshold), responses to size V stimuli occurred ~50 ms faster, and with slightly less variable latencies, compared to those of size III.
Table 1) Response times to size III and size V stimuli, stratified by proximity to individual point-wise thresholds. Near-threshold responses were those to stimuli within ±3 dB of the estimated 50% FOS threshold, and supra-threshold responses were those to stimuli at least 10 dB brighter than the estimated FOS threshold.
Size III Size V
Stimuli near threshold (±3 dB)
Overall median RT, IQR (ms) 495 (470, 530) 500 (450, 530)
individual RT variability, median (ms) 125 135
Stimuli above (>10 dB) threshold
Overall median RT, IQR (ms) 395 (350, 415) 350 (310, 390)
individual RT variability, median (ms) 95 75
Conclusions: We found no evidence for our hypothesis that responses times to near-threshold stimuli of size V were either faster or less variable than those of size III. This suggests that response times either do not reflect perceptual difficulty, or that there was no meaningful difference in perceptual difficulty between near-threshold stimuli of size III and V. We need better objective measures for “human factors” aspects in perimetry.