Visual Field Test (Perimetry) in Ahmedabad — Glaucoma Monitoring at Puja Eye Hospital
A visual field test — also called perimetry — measures the full extent of your vision, including your central vision and your peripheral (side) vision. In glaucoma, vision loss begins at the periphery and progresses inward, and this change is often so gradual that patients do not notice it until a significant portion of vision has already been lost.
Regular visual field testing is one of the most important tools in glaucoma management. It detects functional vision loss, tracks how quickly glaucoma is progressing, and helps Dr. Puja Sheth determine whether your current treatment is adequately protecting your vision.
What Is a Visual Field Test?
During a visual field test (perimetry), you sit in front of a specialised machine and look straight ahead at a central fixation point. At various locations across your field of vision, brief flashes of light appear at different intensities. Each time you see a flash, you press a button to indicate you have detected it.
The machine maps out your entire visual field and identifies any areas where sensitivity is reduced — indicating spots of vision loss. The result is a detailed map of your visual field, with statistical analysis comparing it to normal values for your age.
Why Is Perimetry Important in Glaucoma?
Glaucoma causes progressive damage to the optic nerve. As nerve fibres are lost, corresponding areas of the visual field become less sensitive or disappear entirely. The pattern and extent of visual field loss provides critical clinical information:
- It confirms whether functional (visual) damage is present, in addition to structural (nerve fibre) damage seen on OCT
- It establishes the current severity of glaucoma — mild, moderate, or advanced
- It detects whether glaucoma is progressing despite treatment, prompting a change in management
- It tracks the rate of progression — slow, moderate, or fast — which guides the aggressiveness of treatment
- It documents the patient's visual functional status for long-term clinical records
How Often Is the Visual Field Test Required?
The frequency of visual field testing depends on your individual situation:
- Newly diagnosed patients — typically 2 to 3 tests in the first year to establish a reliable baseline, as individual test results can vary
- Stable glaucoma — usually once or twice per year, depending on severity
- Progressing glaucoma or newly adjusted treatment — more frequent testing, sometimes every 3 to 4 months
- Glaucoma suspects (high-risk individuals without confirmed diagnosis) — typically once a year
Is the Visual Field Test Difficult?
The visual field test requires concentration and sustained attention, and some patients find it tiring, particularly in the first few attempts. It is important to understand that some variability between tests is entirely normal and expected — it does not mean your glaucoma has suddenly worsened.
With practice, patients become more comfortable with the test and results become more consistent. Dr. Sheth always reviews visual field results in the context of multiple tests over time, never making clinical decisions based on a single result in isolation.
The test takes approximately 5 to 10 minutes per eye.
Who Should Have a Visual Field Test?
- All patients diagnosed with any type of glaucoma, as part of routine monitoring
- Glaucoma suspects — patients with elevated eye pressure, suspicious optic nerves, or thin corneas — as part of baseline evaluation
- Patients with a family history of glaucoma who are being monitored annually
- Patients who have noticed any change in their peripheral vision or difficulty in low-light conditions
- Patients being evaluated for neurological conditions that can affect the visual pathway
Role of Visual Field Testing / Perimetry in Neurological Conditions
Visual field testing plays a vital role beyond glaucoma — it is an essential diagnostic tool in neurology and neuro-ophthalmology. The visual pathway travels from the eye through the optic nerve, optic chiasm, optic tracts, and ultimately to the occipital cortex at the back of the brain. Any disruption along this entire pathway — whether from a tumour, stroke, demyelination, or raised intracranial pressure — produces a characteristic pattern of visual field loss that helps localise the site of neurological damage.
- Key neurological conditions diagnosed or monitored with perimetry include:
- Pituitary tumours / Pituitary adenoma — Classic bitemporal hemianopia (loss of both outer visual fields) is the hallmark finding, caused by compression of the optic chiasm. Regular perimetry is critical for monitoring tumour growth and response to treatment.
- Stroke (Cerebrovascular Accident) — Occipital or parietal lobe strokes produce homonymous hemianopia (loss of the same side of vision in both eyes), which perimetry precisely maps and documents.
- Intracranial tumours & space-occupying lesions — Tumours pressing on the optic tract or radiations produce predictable field defects that indicate tumour location.
- Idiopathic Intracranial Hypertension (IIH / Pseudotumour Cerebri) — Raised intracranial pressure causes papilloedema and progressive peripheral field loss; perimetry is key to monitoring whether treatment is protecting vision.
- Multiple Sclerosis (MS) & Optic Neuritis — Demyelination of the optic nerve causes central scotomas or altitudinal defects; field testing tracks recovery and disease progression.
- Occipital lobe epilepsy & migraine with aura — Transient or permanent visual field defects can be mapped and documented.
Puja Eye Hospital- Glaucoma Eye Hospital
- 918780012121
- 401-402, The 132 Offices and Showrooms Near Shell Petrol Pump, Besides Indraprastha Saptak 132 Ft. Ring Road, AEC Cross Rd, Naranpura, Ahmedabad, Gujarat 380013
- Monday to Saturday : 9:30 am–4:30 pm