What is NCT test for eye?

A common glaucoma screening test is non-contact tonometry (NCT). In this test, an instrument emits a brief puff of air at the surface of your eye to indirectly measure the pressure inside your eye (intraocular pressure, or IOP).

What is a normal tonometer reading?

A normal result means your eye pressure is within the normal range. The normal eye pressure range is 10 to 21 mm Hg. The thickness of your cornea can affect measurements. Normal eyes with thick corneas have higher readings, and normal eyes with thin corneas have lower readings.

What is a tono-pen used for?

Indentation Tonometry The Tono-pen is an electronic hand-held device that uses a small plunger to record the force needed to applanate the cornea. The Tono-pen averages multiple readings of this small force that is converted to intraocular pressure [1].

What does a Tono-Pen measure?

Tonometry is a diagnostic test that measures the pressure inside your eye, which is called intraocular pressure (IOP). This measurement can help your doctor determine whether or not you may be at risk of glaucoma.

What is IOP test?

Optic Nerve, picture. A tonometry test measures the pressure inside your eye, which is called intraocular pressure (IOP). This test is used to check for glaucoma, an eye disease that can cause blindness by damaging the nerve in the back of the eye (optic nerve).

How do you test for tonometry?

You will rest your chin on a padded support and stare straight into the microscope (slit lamp). Your doctor sits in front of you and shines a bright light into your eye. Your doctor gently touches the tonometer probe to your eye. Your doctor checks the tension dial on the tonometer that measures the IOP of your eye.

How the tonometry test is done?

Tonometry measures the pressure within your eye. During tonometry, eye drops are used to numb the eye. Then a doctor or technician uses a device called a tonometer to measure the inner pressure of the eye. A small amount of pressure is applied to the eye by a tiny device or by a warm puff of air.

How is IOP measured?

In most ophthalmologist’s offices, eye pressure is measured using “Goldmann applanation tonometry,” and this is considered a “gold standard” eye pressure measurement. In this test, the eyes are anesthetized with numbing drops. Then, a small tip gently touches the surface of the eye and the eye pressure is measured.

What is tonometry Slideshare?

TONOMETRY • Tonometry is the procedure performed to determine the intraocular pressure (IOP). INDENTATION TONOMETER • It is based on fundamental fact that plunger will indent a soft eye more than hard eye. • The indentation tonometer in current use is that of Schiotz .

What is indentation tonometry?

Impression tonometry (also known as indentation tonometry) measures the depth of corneal indentation made by a small plunger carrying a known weight. The higher the intraocular pressure, the harder it is to push against and indent the cornea. The movement of the plunger is measured using a calibrated scale.

What do you need to know about a tonometry test?

Tonometry is a diagnostic test that measures the pressure inside your eye, which is called intraocular pressure (IOP). This measurement can help your doctor determine whether or not you may be at risk of glaucoma. Glaucoma is a serious eye disease that can eventually lead to vision loss if untreated.

Is the Goldmann applanation tonometry test more accurate?

This test is usually considered less accurate than the Goldmann applanation tonometry test. The Tono-Pen is a handheld device that’s shaped like a large marker. It provides a digital readout of eye pressure. Your doctor can use it to touch your eye and measure pressure.

How does a tonometer detect pressure in the eye?

By flattening your cornea just a bit, the tonometer can detect the pressure in your eye. Your eye doctor will adjust the tension until they get a proper reading.

How is the IOP value of a tonometer calculated?

The tonometer end is then pressed onto special paper, producing circle of dye Diameter of circle corresponds to the intraocular pressure. A scale, based on the plunger weight divided by the area of contact, is placed over the ring converting it into an IOP value.