Visual Field Test (Perimetry) in Ahmedabad

No. The visual field test is completely non-invasive and painless. You simply sit in front of the machine and respond to light stimuli. No eye drops, instruments, or contact with the eye are involved.

Missing some flashes is completely normal and expected – no one detects every single stimulus. The test uses statistical analysis to distinguish between normal variability and genuine areas of reduced sensitivity. Dr. Sheth reviews the full statistical report, not just the individual responses.

Yes. You should wear your glasses or contact lenses for the visual field test if you normally use them for near or distance vision. Please bring your glasses to the appointment.

Yes. A single normal visual field test is reassuring but is not a guarantee that glaucoma is absent or stable. Glaucoma is a progressive condition that requires monitoring over time. Regular repeat testing is what allows early detection of any progression.

No. The visual field test is one component of a comprehensive evaluation. Glaucoma is diagnosed based on a combination of optic nerve appearance, OCT findings, eye pressure, and visual field results. No single test is sufficient for diagnosis.

A visual field test, also called perimetry, is a diagnostic test that maps the full extent of your field of vision – both central and peripheral- by measuring your ability to detect light stimuli at different locations in your visual field. In glaucoma, damage to the optic nerve produces characteristic patterns of visual field loss (arcuate scotomas, nasal steps, altitudinal defects) that are precisely documented by perimetry. Perimetry is the primary functional test in glaucoma management: while OCT measures structural nerve damage, visual field testing measures whether that structural damage has translated into functional vision loss. Both are essential for complete glaucoma assessment at Puja Eye Hospital, Naranpura, Ahmedabad.

Puja Eye Hospital uses the Humphrey Field Analyser – the global standard for glaucoma perimetry – for all visual field testing. The Humphrey Field Analyser uses the SITA (Swedish Interactive Thresholding Algorithm) testing strategy, which provides reliable, reproducible results in a shorter test time compared to older full-threshold strategies. Dr Puja Sheth uses 24-2 and 30-2 test patterns for standard glaucoma monitoring, and 10-2 central field testing for advanced glaucoma where central vision is at risk. Reliable Humphrey visual field results are the cornerstone of glaucoma staging and treatment decision-making.

The visual field test is performed in a quiet, darkened room. You sit in front of a bowl-shaped white screen (the perimeter), rest your chin on a support, and fix your gaze on a central target. A series of light dots of varying brightness are flashed at different positions in the visual field. Each time you see a flash, you press a button. The test assesses each eye separately and takes approximately 5–8 minutes per eye using the SITA-Fast strategy, or 8–12 minutes with SITA-Standard. Many patients find the first test challenging – it is a concentration-intensive test – but performance typically improves with practice. Dr. Puja Sheth’s team provides clear instructions and ensures patients feel comfortable before the test begins.

Standard automated perimetry detects functional vision loss only after approximately 25–35% of retinal ganglion cell axons have been lost – meaning early glaucoma may be invisible on perimetry. This is why Dr. Puja Sheth combines visual field testing with structural imaging (Zeiss OCT of the RNFL and optic nerve head) in every evaluation. OCT can detect structural nerve damage before field defects appear, enabling earlier intervention. Once glaucoma is established, however, visual field progression is the most important indicator that treatment is insufficient and needs to be escalated. Serial visual fields over time – analysed with trend and event-based progression analysis – are the backbone of long-term glaucoma management.

The frequency of visual field testing depends on glaucoma severity and stability. Standard glaucoma care guidelines recommend at least two visual field tests per year for most patients with established glaucoma. For patients with rapidly progressing glaucoma or those in whom treatment has recently changed, testing every 3–4 months may be appropriate to reliably detect change. For stable, well-controlled early glaucoma, one to two tests per year is adequate. At Puja Eye Hospital, Ahmedabad, Dr. Puja Sheth tailors the testing schedule to each patient’s risk profile, ensuring that progression is detected promptly and treatment escalated before significant functional loss occurs.

Humphrey visual field results are presented as a numerical map showing sensitivity at each tested location, a grey-scale map showing the pattern of loss visually, and a probability map indicating which areas are abnormal compared to age-matched normals. Key summary indices include Mean Deviation (MD), which indicates overall field loss severity (values more negative than -6 dB indicate moderate loss; more negative than -12 dB indicate severe loss), and Pattern Standard Deviation (PSD), which reflects the pattern of localised loss. Reliability indices – fixation losses, false-positive and false-negative rates – indicate test quality. Dr. Puja Sheth interprets results in the context of the full clinical picture, including OCT, IOP history, and prior field tests, not in isolation.

The visual field test is completely safe, non-invasive, and involves no radiation or injections of any kind. It uses only flashes of light and your responses. No drops are required for the test itself, although pupils may be dilated if the test is being performed as part of a broader evaluation on the same visit. The test carries no risks or side effects. It can be safely performed in pregnant women, children (with modified protocols), and patients with systemic conditions. The only requirement is that you can sit still, hold your gaze steady, and respond to light stimuli – the test coordinator will guide you through each step.

Visual field testing using the Humphrey Field Analyser is available at Puja Eye Hospital, Naranpura, Ahmedabad, under the supervision of Dr. Puja Sheth. Tests are performed by trained ophthalmic technicians following a standardised protocol to ensure data quality. Results are reviewed and interpreted by Dr. Puja Sheth in the context of your full clinical picture. The clinic accepts both self-referred patients and those referred by other eye specialists or physicians across Ahmedabad and Gujarat. Appointments can be scheduled in advance; urgent cases presenting with symptoms of acute angle closure or sudden vision change are prioritised.