Glaucoma and suspected glaucoma
Standard automated perimetry is used to assess functional damage and monitor changes in the visual field.
About the service
Perimetry tests the visual field and helps identify areas of reduced sensitivity. The doctor interprets the result alongside test reliability and other examination findings.
Who the service is for
Symptoms of field loss
If a person notices a dark area, tunnel-like vision, part of the image missing or difficulty orienting to the side, the doctor may prescribe visual-field testing.
Optic nerve disorders
Perimetry helps quantify defects in optic neuropathies, neuritis, ischemic damage and optic nerve atrophy.
Neurological conditions
When a lesion of the optic chiasm or visual pathways is suspected, after stroke, or with tumours and other neurological processes, the visual-field map helps localize the functional defect.
Retinal disorders
When indicated, perimetry is used to assess functional field loss in certain retinal dystrophies and other retinal disorders.
Follow-up over time
Repeat tests using the same strategy allow visual fields to be compared over time. A comparable protocol and sufficient examination quality are especially important for trend analysis.
Keeping the gaze fixed
Each eye is tested separately. Look at the fixation target and press the button only when you actually see the light stimulus; do not try to guess stimuli.
Factors affecting quality
Poor fixation, high false-positive response rates, fatigue, ptosis, the edge of a corrective lens, markedly reduced vision and other factors can distort the map.
Monitoring over time
Progression cannot be assessed from a single “worse-looking” map. Monitoring requires comparable tests, quality analysis and a series of observations.
Eye shape and measurements
MD, PSD, VFI and equivalent indices depend on the platform and selected strategy. Their meaning and thresholds cannot be transferred mechanically between different instruments and programs.
Visual field
The perimeter does not establish a diagnosis automatically. A visual-field map is a functional result that the doctor interprets together with the examination and other investigations. A high false-positive rate can make the visual field appear artificially better.
Patient education
The first threshold test may differ from subsequent tests because of the learning effect. If a result does not fit the clinical picture or quality is low, the doctor may order a repeat examination.
Keeping the gaze fixed
False-negative responses and fixation losses are also assessed, but interpreted in the context of defect severity and patient behaviour.
Optic nerve
Normal perimetry does not exclude every eye or optic nerve disorder.
Glaucoma and eye pressure
In glaucoma, structural and functional changes are assessed together.
Preparation
Special preparation is usually unnecessary. Bring your glasses and previous visual-field results, and try not to attend when very tired.
Optical correction
Pupil dilation is usually unnecessary for perimetry. If your pupils have been dilated for another test, agree the timing with the specialist because changes in pupil size and optical correction may affect the result.
Preparing for the service
No fasting or special diet is required for perimetry itself. Preparation may differ if other examinations are scheduled during the same visit.
Results and documents
Bring your distance and/or reading glasses if you use them, as well as previous visual-field printouts. Appropriate refractive correction can be important for threshold perimetry.
Dryness and the ocular surface
Tell the specialist if you are very tired, unwell, have marked eye pain or dryness, or find it difficult to maintain fixation. These factors may increase test variability.
When urgent care is needed
Sudden loss of half the visual field, a new curtain, sudden visual deterioration, weakness or numbness on one side of the body, speech disturbance or severe headache requires urgent medical assessment rather than scheduled perimetry.
When urgent examination is needed
Sudden loss of part of the visual field, particularly with neurological symptoms, flashes, a curtain-like shadow, pain or a sudden reduction in vision, requires urgent assessment.
Limitations and safety
The perimeter does not establish a diagnosis automatically. A visual-field map is a functional result that the doctor interprets together with the examination and other investigations.
Book a consultation
Stages
Stage 1
Clarifying the purpose
The doctor or diagnostic specialist determines the purpose: glaucoma monitoring, searching for a neurological defect, assessment of the optic nerve or retina, or another clinical situation.
Takes: 1 min
Stage 2
Preparation for the test
The team checks which eye is being examined and whether optical correction is needed for the test distance, positions the head correctly and explains how to respond.
Takes: 1 min
Stage 3
First-eye testing
The patient looks at the central target.
Takes: 15 min
Stage 4
Examination of the second eye
The procedure is repeated for the second eye according to the selected protocol.
Takes: 15 min
Stage 5
Quality control
The specialist assesses fixation, false-positive and false-negative responses, gaze and patient behaviour, and other signs of reliability.
Takes: 2 min
Stage 6
Medical interpretation
The ophthalmologist analyses the map and global and local indices, comparing them with previous tests, OCT, intraocular pressure, optic-disc examination and the clinical objective.
Takes: 5 min
Service benefits
Checking the visual field
Perimetry shows how a person detects objects in central and peripheral vision.
Assessing visual function
Testing helps detect functional deficits that visual acuity alone cannot describe.
Monitoring change
Comparable repeat measurements help the doctor detect deterioration or stability.
Checking treatment effectiveness
Changes in measurements help determine whether treatment is sufficient or needs review.
Methods comparison
Criterion
Static automated threshold
Static suprathreshold
Kinetic
Confrontation
Principle
Stationary stimuli are presented at predefined locations and brightness is varied to estimate sensitivity threshold.
Stationary stimuli are presented above the expected threshold to screen rapidly for suspicious locations.
A stimulus moves from a non-seeing to a seeing area to map field boundaries and isopters.
The examiner compares the patient’s field with their own during a bedside/office confrontation test.
Main purpose
Quantify local light sensitivity and defects within the tested grid.
Rapid screening for possible defects that may require detailed threshold testing.
Map outer field boundaries, marked peripheral defects and residual islands of vision.
Rapidly detect large defects such as hemianopia; not a fine quantitative test.
Glaucoma
Key functional method for diagnosis and follow-up, particularly central threshold standard automated perimetry.
May be used for screening or selected follow-up situations when fields were previously normal.
Useful in selected cases, including very advanced loss or when standard automated testing is impractical.
Not sufficiently sensitive for formal detection or monitoring of typical early glaucomatous defects.
Neurological defects
Quantifies central hemianopic or quadrantanopic defects within the selected program well.
Can detect major loss but with less detail than threshold testing.
Useful for wide peripheral defects and severe functional loss.
Useful as a rapid bedside screen for large defects and to decide whether formal perimetry is needed.
Physician output
Sensitivity map, local probability plots and, depending on platform, global indices and progression tools.
Seen/missed stimulus map with less information about defect depth.
Isopters and a geometric map of field boundaries or remaining islands.
Qualitative description of a large complete/incomplete defect or gross asymmetry.
Dependence on patient response
High: fixation, attention and appropriate button responses are essential.
High, although the test is often shorter.
High: the patient must report when the moving stimulus becomes visible.
High and additionally dependent on examiner technique.
Learning effect
Well recognized; early tests can be more variable.
Possible, especially in inexperienced patients.
Possible, although variability differs from automated threshold testing.
Not quantified by standard reliability indices; strongly influenced by instructions and interaction.
Repeatability for follow-up
Best when the same device/strategy is used with acceptable reliability; some platforms provide serial progression analyses.
Useful for repeat screening but less detailed for quantitative progression.
Can be repeated if stimulus, technique and conditions are standardized.
Limited precision for monitoring small quantitative changes.
Far peripheral field
Program-dependent; common central programs do not map the entire far periphery.
Depends on the selected grid.
A strength: can map a substantially wider field.
Can roughly assess peripheral loss but with low sensitivity.
Central 10 degrees
Dense central programs can assess this area in detail.
Screening is possible if an appropriate program exists.
Less suited to fine threshold measurement of central sensitivity.
Not suitable for detailed mapping of small central scotomas.
Eye contact
Non-contact.
Non-contact.
Non-contact.
Non-contact.
Pupil dilation
Usually not required; pupil size and sequencing with other examinations may affect comparability.
Usually not required.
Usually not required.
Not required.
Main limitations
Fatigue, poor fixation, false responses, incorrect optical correction, ptosis/anatomy, severe visual loss and learning effect.
Less quantitative detail; abnormal screening often requires threshold testing.
More operator-dependent; requires standardized stimulus size, brightness, speed and technique.
Low sensitivity to small or early defects; cannot replace formal perimetry.
Static automated threshold
Principle
Main purpose
Glaucoma
Neurological defects
Physician output
Dependence on patient response
Learning effect
Repeatability for follow-up
Far peripheral field
Central 10 degrees
Eye contact
Pupil dilation
Main limitations
Stationary stimuli are presented at predefined locations and brightness is varied to estimate sensitivity threshold.
Quantify local light sensitivity and defects within the tested grid.
Key functional method for diagnosis and follow-up, particularly central threshold standard automated perimetry.
Quantifies central hemianopic or quadrantanopic defects within the selected program well.
Sensitivity map, local probability plots and, depending on platform, global indices and progression tools.
High: fixation, attention and appropriate button responses are essential.
Well recognized; early tests can be more variable.
Best when the same device/strategy is used with acceptable reliability; some platforms provide serial progression analyses.
Program-dependent; common central programs do not map the entire far periphery.
Dense central programs can assess this area in detail.
Non-contact.
Usually not required; pupil size and sequencing with other examinations may affect comparability.
Fatigue, poor fixation, false responses, incorrect optical correction, ptosis/anatomy, severe visual loss and learning effect.
Stationary stimuli are presented above the expected threshold to screen rapidly for suspicious locations.
Rapid screening for possible defects that may require detailed threshold testing.
May be used for screening or selected follow-up situations when fields were previously normal.
Can detect major loss but with less detail than threshold testing.
Seen/missed stimulus map with less information about defect depth.
High, although the test is often shorter.
Possible, especially in inexperienced patients.
Useful for repeat screening but less detailed for quantitative progression.
Depends on the selected grid.
Screening is possible if an appropriate program exists.
Non-contact.
Usually not required.
Less quantitative detail; abnormal screening often requires threshold testing.
A stimulus moves from a non-seeing to a seeing area to map field boundaries and isopters.
Map outer field boundaries, marked peripheral defects and residual islands of vision.
Useful in selected cases, including very advanced loss or when standard automated testing is impractical.
Useful for wide peripheral defects and severe functional loss.
Isopters and a geometric map of field boundaries or remaining islands.
High: the patient must report when the moving stimulus becomes visible.
Possible, although variability differs from automated threshold testing.
Can be repeated if stimulus, technique and conditions are standardized.
A strength: can map a substantially wider field.
Less suited to fine threshold measurement of central sensitivity.
Non-contact.
Usually not required.
More operator-dependent; requires standardized stimulus size, brightness, speed and technique.
The examiner compares the patient’s field with their own during a bedside/office confrontation test.
Rapidly detect large defects such as hemianopia; not a fine quantitative test.
Not sufficiently sensitive for formal detection or monitoring of typical early glaucomatous defects.
Useful as a rapid bedside screen for large defects and to decide whether formal perimetry is needed.
Qualitative description of a large complete/incomplete defect or gross asymmetry.
High and additionally dependent on examiner technique.
Not quantified by standard reliability indices; strongly influenced by instructions and interaction.
Limited precision for monitoring small quantitative changes.
Can roughly assess peripheral loss but with low sensitivity.
Not suitable for detailed mapping of small central scotomas.
Non-contact.
Not required.
Low sensitivity to small or early defects; cannot replace formal perimetry.
Comparison with Related Modalities in Glaucoma and Optic Nerve Pathology
Criterion
Perimetry
Optic nerve / RNFL-GCC OCT
Tonometry
What is measured
Functional light sensitivity and visual field.
Retinal, RNFL/GCC and optic nerve head structure.
Intraocular pressure at the time of measurement.
Main clinical question
Where and how much is visual function reduced?
Is there structural damage and how marked is it?
What pressure is measured and how does it relate to individual risk/target?
Role in glaucoma
Functional standard for detecting and monitoring field loss.
Structural assessment that complements function and serial follow-up.
Key risk factor and treatment target, but IOP alone is not diagnostic.
Does it replace the other tests?
No.
No.
No.
Dependence on patient response
Substantial because perimetry is psychophysical.
Lower, although fixation, segmentation and artifacts affect image quality.
Usually limited, but dependent on method and measurement conditions.
Longitudinal comparison
Using a comparable protocol/strategy is especially important
Prefer the same platform and review image quality/segmentation.
A series of measurements is more informative than a single number; timing, therapy and other factors matter.
Practical output
Field map, thresholds/indices and reliability information.
Cross-sectional images, thickness maps and quantitative structural metrics.
IOP value interpreted in clinical context.
Perimetry
What is measured
Main clinical question
Role in glaucoma
Does it replace the other tests?
Dependence on patient response
Longitudinal comparison
Practical output
Functional light sensitivity and visual field.
Where and how much is visual function reduced?
Functional standard for detecting and monitoring field loss.
No.
Substantial because perimetry is psychophysical.
Using a comparable protocol/strategy is especially important
Field map, thresholds/indices and reliability information.
Retinal, RNFL/GCC and optic nerve head structure.
Is there structural damage and how marked is it?
Structural assessment that complements function and serial follow-up.
No.
Lower, although fixation, segmentation and artifacts affect image quality.
Prefer the same platform and review image quality/segmentation.
Cross-sectional images, thickness maps and quantitative structural metrics.
Intraocular pressure at the time of measurement.
What pressure is measured and how does it relate to individual risk/target?
Key risk factor and treatment target, but IOP alone is not diagnostic.
No.
Usually limited, but dependent on method and measurement conditions.
A series of measurements is more informative than a single number; timing, therapy and other factors matter.
IOP value interpreted in clinical context.
Comparison with adjacent tests in glaucoma and optic nerve assessment
Book a visual field test
Book perimetry if it has been prescribed by your ophthalmologist or if functional assessment is needed for glaucoma, optic nerve, retinal or visual pathway disease. If visual-field loss appeared suddenly, mention this when contacting the clinic because urgent assessment may be required.
Procedure prices
Service name
Price
Static computerized perimetry (per eye)
from 2 800 ₸
Perimetry (per eye)
from 2 100 ₸
Central visual field assessment (per eye)
from 2 600 ₸
Our doctors
A team of experienced doctors across specialties.
Experience: 17 years
Ophthalmologist, Ultrasound and OCT Diagnostics
Zhanysbaeva Akmaral Esmyrzaevna
Highest-category ophthalmologist
Experience: 13 years
Ophthalmologist
Kalshabekov Alibi Sembaevich
Highest-category ophthalmologist
Experience: 18 years
Ophthalmologist, Ultrasound and OCT Diagnostics
Musaeva Zarina Maksimovna
Highest-category ophthalmologist
Experience: 12 years
Ophthalmologist
Tadzhimetov Murat Mikhaylovich
Highest-category ophthalmologist
Experience: 17 years
Ophthalmologist
Tokymbaeva Zhenisgul Nurmankyzy
Highest-category ophthalmologist
Experience: 8 years
Ophthalmologist
Ondosinov Eldos Nurbekuly
Second-category ophthalmologist
Experience: 14 years
Ophthalmologist
Botabekov Rustem Makhamadalievich
Experience: 7 years
Ophthalmologist
Zhunusov Omirkhan Maratuly
Experience: 10 years
Ophthalmologist, Ultrasound and OCT Diagnostics
Kulamanova Bayan Adilbekovna
Experience: 14 years
Ophthalmic Diagnostics Physician
Nurzhanova Dinara Nurbolatovna
Perimetry — Visual Field Testing
What is the visual field?
The visual field is the area a person can see while keeping their gaze fixed.
Perimetry does not measure how small a line of letters a patient can read on an eye chart. It assesses a different function: where, and with what sensitivity, the visual system detects a light stimulus.
The test measures light sensitivity at different points in the central and peripheral visual field. It helps identify localized areas of visual field loss, called scotomas, narrowing of the visual field, and characteristic patterns of impairment.
How is the test performed?
In static computerized perimetry, light stimuli appear at predefined locations and vary in brightness. Based on the patient’s responses, the software estimates the threshold of light sensitivity and produces a visual field map.
In kinetic perimetry, a stimulus moves from an area where the patient cannot see it into an area where it becomes visible. This helps define the boundaries of the visual field and its isopters — lines connecting points of equal light sensitivity.
The method is selected according to the clinical purpose of the examination.
When is perimetry used?
In glaucoma, perimetry reveals functional changes and helps detect and monitor characteristic visual field defects.
However, a diagnosis is not based on a single visual field test. The findings are assessed alongside intraocular pressure, the appearance of the optic disc, optical coherence tomography (OCT) results — including assessment of the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) — gonioscopy when indicated, and other clinical findings.
Perimetry is also used in conditions affecting the optic nerve and visual pathways, certain retinal diseases, and following neurological events. The pattern of a defect may help the clinician identify the location of damage, but the visual field map alone cannot establish its cause without clinical context.
What affects the accuracy of the results?
Perimetry is a psychophysical test. Its results depend not only on the equipment but also on the patient’s fixation, attention, and responses.
The clinician therefore assesses test reliability and possible artifacts. When necessary, the examination is repeated using a comparable protocol.
What does the patient receive?
The patient receives a visual field map, while the clinician obtains quantitative data to support diagnosis and monitor changes over time.
Further procedure details
First-eye testing
The patient looks at the central target. Light stimuli appear at different points, and the patient presses the button when they actually notice them.
Examination of the second eye
The procedure is repeated for the second eye according to the selected protocol. Duration depends on the strategy, number of test points and the patient’s ability to maintain attention.
Additional advice and situations
If the result is within the expected range
The physician compares the visual field with other findings. A normal map does not cancel follow-up when risk factors or structural abnormalities remain.
If a new defect is found
Test quality and anatomical/clinical plausibility are checked first. The field may be repeated or additional tests may be ordered.
If the test is unreliable
The specialist may repeat instructions, improve positioning or optical correction, or choose another strategy/program.
If the patient is monitored for glaucoma
Comparable test strategies are preferred. The physician reviews the sequence of fields, not only the current printout.
If a neurological cause is suspected
The field pattern may prompt neurological assessment and CNS imaging when clinically indicated.
If retinal disease is present
Perimetry may be combined with OCT, fundus photography and other tests depending on the suspected retinal location and disease.
Facts and offers
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Related services
Frequently asked questions
What is visual field testing?
Perimetry measures the visual field by presenting light stimuli at different locations and creating a map of sensitivity and defects from the patient’s responses.
How is visual field different from visual acuity?
Visual acuity measures fine central detail. Perimetry assesses what is detected at different central and peripheral locations while fixation is maintained.
What can computerized perimetry show?
It can reveal local scotomas, diffuse or sectoral sensitivity loss, field constriction and characteristic patterns of visual-field defects.
Can perimetry diagnose glaucoma by itself?
No. It is a key functional test in glaucoma, but diagnosis is based on the complete clinical picture including optic nerve findings, IOP, OCT and other examinations.
Does a normal field rule out glaucoma?
No. Early structural abnormalities or other disease may exist despite a field within normal limits. Structure and function are interpreted together.
What is the difference between static and kinetic perimetry?
Static testing changes stimulus brightness at fixed locations to estimate sensitivity. Kinetic testing moves a stimulus to outline field boundaries or isopters.
What is threshold perimetry?
It is a static strategy that estimates the dimmest stimulus the patient can detect at each tested location.
What is suprathreshold screening?
It is a faster strategy using stimuli brighter than the expected threshold to identify suspicious locations. Abnormal screening may require a full threshold test.
What is the central visual field?
It is the area around fixation that is particularly important for reading and detail vision and for many glaucomatous or neurological defects. The exact tested radius depends on the program.
What are MD, PSD and VFI?
They are examples of global indices used on certain automated perimetry platforms. They summarize overall depression, localized irregularity or a functional index and must be read with the maps and device-specific context.