The Normal visual field is depicted as Traquair’s “Island of vision surrounded by a sea of blindness”
The three dimensional concept can be reduced to quantitative values by plotting lines (isopters) at various levels around the island or by measuring the height (sensitivity) at different points within the island of vision.
The normal visual field and glaucomatous changes in visual field are the same as when Bjerrum discovered the arcuate scotoma using back of his consulting room door as a background for testing visual field nearly 110 years ago.
Advances in the technology of visual field testing are changing our perception of normal and abnormal visual fields.
Influence of Glaucoma on Visual Function
Understanding about natural history of progressive visual field loss is continuously increasing with newer instruments and technologies which has increased the sensitivity of test
The visual field defects that are caused by loss of retinal nerve fiber bundles are the most common and familiar change, the central vision is typically one of the last region to be lost
Influence of Glaucoma on Visual Function
Studies have shown that mild central and diffuse reduction in the visual field can occur even in early stage of glaucoma
Visual Field defects in Glaucoma
Enlargement of blind spot
Nerve fiber bundle defects:
a. Scatter (fluctuation/localized minor disturbances): they are variable threshold responses to repeated testing in the same area. Scatter is studied with differential light threshold. It is considered early warning sign of glaucoma
Visual Field defects in Glaucoma
b. Arcuate defect
c. Nasal step
d. Vertical step
e. Temporal sector defect
Other Conditions Affecting Visual Field
Retinal Diseases including pigmentary dystrophies and vascular diseases
Advanced Glaucomatous Field Defects
Complete double arcuate scotoma with extension to peripheral limits in all areas except temporally
This results in a central island and a temporal island of vision in advanced glaucoma
Other Measures of Visual Impairment in Glaucoma
i. Spatial contrast sensitivity decreases : impairment correlates with the central field and optic nerve head damage
ii. Temporal contrast sensitivity (Flickering visual stimulus) glaucoma patients have reduced function
Techniques of Visual Field Analysis
Determination of outer boundary of the visual field is one aspect of testing the visual field, but it is of limited value. More important is the fact that every point within the boundary has certain characteristics of visual function.
Acuity away from the fovea can be measured for the purpose of visual field testing. In perimetry functional ability in terms of the weakest spot of light (visual stimulus) that can be seen at different location in the visual field is quantified
Techniques of Field Charting
In visual field charting both the peripheral limits of a visual field and the relative visual acuity of areas within those areas are recorded
Visual fields can be charted by using kinetic and/or static techniques with instruments that are operated either manually or computer assisted (automatic)
Involves moving of the test object from non-seeing to seeing area and point at which it is first seen in relation to fixation point. This procedure documents the boundaries of the visual field for:
a. absolute limits
b. areas of relative differences in visual acuity with in the field
The best known of the kinetic perimeters is referred to as the Goldmann-type projection perimeter. This type perimeter is named after Dr. Hans Goldmann, a European ophthalmologist who did much of the original design and testing on the hemispherical bowl concept.
Available Goldmann-type perimeters are manually operated. The operator selects the target (stimulus), size and intensity, moves the target within the bowl, monitors patient fixation and records responses on the chart. In some cases, automatic recording is provided which provides for automatic marking of the field of vision chart each time the patient presses the response button.
Boundaries or contour lines are called isopters. The size of isopter depends on the stimulus value of the test object
Kinetic targets: a stimulus velocity of 4 degree per second appears to be optimal for all targets in the central and peripheral visual field
Background illumination for manual perimetric techniques has traditionally been mesopic to stimulate both rods and cones. Field luminances used ranges from photopic to mesopic, 4 – 31.5 apostilbs
Static technique involves the presentation of stationary test objects using suprathreshold or threshold presentation
Suprathreshold static presentation is an “off & on” technique in which an object just above the anticipated threshold for the field is presented for 0.5 to 1 second and the point at which the patient fails to recognize the target are noted. Spot checking is done for areas of relative or absolute blindness usually in 30 degree central visual field
Threshold static (Profile) perimetry measures the relative intensity thresholds for the visual acuity of individual retinal points within the field of vision. Light intensity is increased gradually and the level at which patient is able to recognize target is recorded or by decreasing light from suprathreshold value to lowest stimulus value seen
Point can be tested in one meridian in radiating manner or circular manner
The more common technique with automated perimetry is to test retinal points distributed in a portion of the visual field and record the visual thresholds as symbols or numerical values
Threshold static perimetry has been shown to be more sensitive than kinetic perimetry in detecting glaucomatous field loss
Although automated perimeters are being used with increasing frequency, the older manual perimeters still provide valuable information, especially when the test is performed by a skilled observer
Selective perimetry or the Armaly-Drance technique: in this method Goldmann type perimeter with suprathreshold static perimetry is used to test central area field and both suprathreshold static and kinetic perimetry to examine the peripheral field with emphasis on the nasal and temporal periphery
The first era of perimetry – mid 19 th century, the work of von Graefe provided Tangent Screens and Arc perimeters.
They were lacking standardization
In middle 20 th century Goldmann perimeter brought standardization
The problem of subjectivity of both patient and perimetrist remained
The problem of subjectivity of perimetrist was eliminated by automation which began in the 1970s
Automated perimetry improved the uniformity and reproducibility of visual fields
Utilization of computers has provided new capabilities that were not possible with manual perimetry, including random presentation of targets, estimation of patient reliability and statistical evaluation of data at different levels
Automated perimetry is more accurate and informative (but it is neither fast nor cheap)
Factors Influencing Field
In perimetry the following factors influence the visibility of white target:
1. Size/ diameter/ area of the spot
2. luminous intensity of the spot
3. Background illumination
Influence of moving spot
As the stimulus moves across the retina, a temporospatial summation occurs that makes kinetic stimuli more visible than the static ones. This phenomenon is more striking in disease conditions in which large intense objects are not seen until they move (Riddoch phenomenon). Statokinetic dissociation (Riddoch phenomenon) seen in hemianoptic field defect
Neurological types of field defects
Points in favour of Kinetic
Glaucoma rarely affects mean deviation appreciably without first producing a localized defect
It is rare for a neurologic field defect to affect only the area outside 30 degrees
Points in favour of kinetic
Automated static perimetry particularly, threshold perimetry is different experience for patient from kinetic perimetry. Automated static test is longer, and target is stationary and everything appears dimmer to the patients. Therefore patient finds automated perimetry more difficult and stressful compared to kinetic perimetry
In kinetic perimetry the test consists of sequence in which the light comes on, gets brighter then he conveys its recognition by pressing button, then light goes off, then again the stimulus comes in similar manner.
Whereas in automated static perimetry the light goes on and stays only for 0.2 second and it goes off irrespective of whether patient see it or not and respond to it
Why is Goldmann Kinetic Perimetry so important
Kinetic perimetry is optimal for the more steeply descending periphery and is much faster than the static method in this region. It is ideal for advanced defects or patients having problems understanding static testing. Static perimetry is ideal for measuring the rather flat shape of the central 30° field and is more sensitive than the kinetic method to detect early visual field loss.
Many patients hate perimetry, as it demanding task that requires attentiveness and an effort to give the “correct answer” , the test is as stressful as school examination. The patient must realize that the field examination is a subject medical test of their visual function and it is not to test their intellectual, artistic or physical abilities
Disadvantages of kinetic perimetry include:
the lack of automation provided by most instruments,
lack of computerized, normative, age-related comparison of results,
the need for an experienced tester,
the potential for missing subtle scotomas,
and the length of time required to perform the tests
Shortcomings of traditional Goldmann kinetic perimetry
Regular training of examiner is reflected in the quality of the result
Regular manual calibration of the instrument required
Quality guidelines recommended (Standard set of parameters, Verification of the blind spot, Surveillance of the eye)
Automated Kinetic Perimeters
Tasks that can be performed with present generation of automated perimeters
1. Evaluation of central and peripheral visual fields
2. Evaluation of blind spot
3. Correcting for reaction time
4. Examination of peripheral isopter
5. Superimposition of static field
Automated Kinetic Perimeters
6. Superimposition of visual field and fundus image
7. Underlay fundus image
8. Underlay previous fields
9. Create an automated examination
10. Run an automatic examination
Negative aspect of static testing
About 30% of all highly pathological patients cannot be tested with static perimetry. Part of the problem is that the reliability of the test is not guaranteed because of the variability of the answers the patients will give.
Author does not have any financial or trade interest in any of the companies instruments of which are mentioned presentation
Advantages of OCTOPUS computer assisted Goldmann kinetic perimetry
1:1 Goldmann Functionality
Patented Reaction time compensation
Resolution down to 0.1° enabling to accurately test the blind spot
Calculation of isopter and scotoma areas
Automatic retest of once established kinetic field
Superposition of static field
True full field perimeter
Produces comparable results
Quick transition from traditional Goldmann
Studies in favour of Kinetic Perimetry
The use of semi-automated kinetic perimetry (SKP) to monitor advanced glaucomatous visual field loss Graefe's Archive for Clinical and Experimental Ophthalmology Volume 246, Number 9 / September, 2008 Pages 1331-1339 J. Nevalainen, J. Paetzold, E. Krapp, R. Vonthein, C. A. Johnson and U. Schiefer
Purpose and Conclusions
Purpose (i) To compare visual field (VF) results obtained with semi-automated kinetic perimetry (SKP) and automated static perimetry (ASP) in patients with advanced glaucomatous VF loss, (ii) to evaluate test-retest reliability of SKP and ASP and (iii) to assess patients’ preference for SKP and ASP.
Conclusions The comparability between SKP and ASP is satisfactory and within the range of the test-retest reliability of ASP . SKP shows slightly better test-retest reliability than ASP. The majority of patients with advanced glaucomatous visual field loss prefer SKP instead of ASP . SKP is a valuable alternative to ASP in monitoring advanced glaucomatous visual field loss.
Comparison between semiautomated kinetic perimetry and conventional goldmann manual kinetic perimetry in advanced visual field loss NOWOMIEJSKA Katarzyna (1 2) ; VONTHEIN Reinhard (3) ; PAETZOLD Iens (1) ; ZAGORSKI Zbigniew (2) ; KARDON Randy (4) ; SCHIEFER Ulrich (1) ; Ophthalmology ISSN 0161-6420 CODEN OPHTDG Source / Source 2005, vol. 112, no8, pp. 1343-1354 [12 page(s) (article)] (29 ref.)
Purpose and Conclusions
Purpose: To compare quantitatively visual field (VF) results obtained using a new standardized semiautomated kinetic perimetry (SKP) with those obtained by conventional Goldmann manual kinetic perimetry (MKP) in patients with advanced VF loss.
Conclusions: Their results indicated that SKP isopter shape and size were very comparable to those obtained on the same eyes with MKP. Semiautomated kinetic perimetry may represent a more standardized method of kinetic perimetry, which still takes advantage of perimetrist-patient interaction to diagnose and monitor advanced VF loss in clinical practice.
Kinetic perimetry Author: SHIKISHIMA KEIGO (Fac. Medicine, Jikei Univ. School of Medicine, JPN) Ophthalmology VOL.48; NO.10; PAGE.1433-1438 (2006)
The test result with GP were more reliable than one with the automated perimeter in cases of old people and of poor visual acuity . Also, it was superior in pattern recognition of the visual field, detection of psychogenic visual field abnormality, grasp of a peripheral part of visual field and evaluation of visual abnormality depending on whether the visual field is in line with meridian or not.
In addition, the points to be kept in mind in interpretation of abnormal visual fields including Riddoch phenomenon , factors which affect abnormal perimetry and psychogenic visual field abnormality are described.
A Comparison of Semiautomated Versus Manual Goldmann Kinetic Perimetry in Patients With Visually Significant Glaucoma. Original Studies Journal of Glaucoma. 17(2):111-117, March 2008. Ramirez, Adriana M. MD *; Chaya, Craig J. MD +; Gordon, Lynn K. MD, PhD * ++; Giaconi, JoAnn A. MD * ++
Purpose and Conclusions
Purpose: To determine if semiautomated kinetic perimetry (SKP) is reproducible and comparable to Goldmann manual kinetic perimetry (GVF).
Conclusions: SKP and GVF testing produced similar visual field results in glaucoma patients, and SKP testing seems to be reliable and reproducible in this population. However, overlapping isopters, typically associated with nonorganic vision loss, and jagged isopters were sometimes observed in SKP visual fields. Further study of SKP is needed to explore these findings.
I have tested for you. Automated kinetic perimetry Publication Type: Comparative Study; English Abstract; Journal Article Journal: Journal français d'ophtalmologie (J Fr Ophtalmol). Reference: 2006-May; vol 29 Spec No 2 (issue ) : pp 36-9 PMID: 17072220 (status: MEDLINE) (last retrieval date: 12/12/2007)
Authors compared the kinetic perimetry of the Humphrey Field Anayzer and the Haag Streit Octopus 101 and assessed their use in relation to Goldmann perimetry. The Humphrey kinetic perimetry comes close to Goldmann perimetry and the Octopus shows clear advantages, notably in terms of ergonomics and its more sophisticated software. The Goldmann requires a high level of skill; examination time with the Humphrey and the Octopus is at least double the time required by a skilled Goldmann operator.
Conclusions … Contd
The examiner can to a certain degree be passive during the static visual field examination, but is entirely active during the kinematic visual field examination. Therefore, contrary to static perimetry, the examination can only be performed by a physician. The future of automated kinematic perimetry depends on simplification of the software.
Computerized kinetic perimetry detects tubular visual fields in patients with functional visual loss American Journal of Ophthalmology Volume 137, Issue 5, May 2004, Pages 933-935 Stacy L. Pineles BSE and Nicholas J. Volpe MD
This test used a computerized kinetic examination to reduce the subjective nature of tangent screen testing for tubular visual fields and to provide a computerized recording of visual fields. This method is a novel and easy-to-use technique to demonstrate functional visual loss.
Goldmann Kinetic perimetry in manual, semi-automatic and automatic modes.
30° threshold test in 2.5 minutes
Octopus "No Fixation Loss" technology provides actionable data for doctors
OCULUS CenterField Perimeter
Finally, a Compact 70º Static/Kinetic/Colour Perimeter The Centerfield automatically performs static and kinetic perimetry in a 36º visual field. Expands to 70º with a fixation shift. Offers white /white and blue /yellow colour perimetry. Screening. Supra, fast, and normal threshold measurements. Popular 30-2, 24-2, and 10-2 grids. That's Incredibly Precise Designed to the Goldmann standard
COMPARISON OF AUTOMATED KINETIC AND STATIC VISUAL FIELDS IN NEURO-OPHTHALMOLOGY PATIENTS Perimetry Update 1988/89, pp. 3-8 Proceedings of the VIIIth International Perimetric Society Meeting edited by A Heijl Kugler & Ghedini Publications, Amsterdam, Berkeley, Milan
Eighty-three patients with various neuro-ophthalmic diseases were submitted to a standard automated protocol including kinetic and static perimetry
The results of this study indicated that the ideal evaluation of neuro-ophthalmology patients should include complete kinetic and static fields. Both examinations present significant advantages, namely, the static examination assesses more precisely the volume of large paracentral scotomas and the kinetic examination is more sensitive and reliable for the detection of relative scotomas at eccentricities of over 15 degrees.
Humphrey® HFAII -i Field Analyzer. Precision and less time. Exactly as Goldmann specified The HFA II- i Field Analyzer meets all requirements for state-of-theart static and kinetic perimetry.
Goldmann Kinetic Perimeter
Difficult Cases for Kinetic Perimetry
Cases of early qualitative changes
Difficult Cases for Static Perimetry
Advanced field changes found in cases of glaucoma
Hemianoptic visual field changes seen in cases of neurological disorders
Superposition of VF and fundus image
Superimposition of visual field on colored fundus photograph is possible for better interpretation
SUPERIMPOTION OF STATIC FIELDS
Superimposition of static visual field is possible on kinetic visual field for better interpretation
Static and Kinetic perimetry, both record visual fields and have their place in evaluation of cases of Glaucoma, neurological and retinal disorders.
There are some cases where static perimetry may be difficult, like cases of advanced glaucomatous field defects, neurological diseases and retinal vascular diseases.
The major disadvantage of kinetic perimeters i.e. lack of standardization has been rectified with automated kinetic perimeters