Suffering from a refractive vision error can be difficult. One of the most common refractive errors is nearsightedness, or myopia. Though the structure of your eye is solely responsible for your myopia, you can take steps to slow it down. At Eye See in Lincolnshire, IL, we can help. Our optometrist, Dr. Nakhlis, and her certified optometry team are specialists in myopia management and control.
Understanding Myopia
With myopia, you can see clearly if an object is up close, but far away objects appear blurry. This happens when your eyeball grows too long or when the cornea (outer covering of your eye) curves too much that it focuses the light getting into the eye incorrectly. This is called a refractive error.
A refractive error happens when your eyeball shape refracts or bends the light getting to the retina incorrectly. When the cornea focuses light in front of the retina, instead of on the retina, your vision becomes blurry.
Refractive error measurement is used together with axial length to measure the progress and success of myopia management. It also predicts high myopia.
Measuring Axial Length in Myopia
Axial length (AL) is the distance from the cornea surface to the fovea in the retina. Our optometrist measures the axial length using ultrasound biometry and optical biometry.
Ultrasound Biometry
The immersion A-scan (amplitude scan) biometry method is often preferred when measuring the axial length in children. This ultrasound technique does not touch the cornea. You also don’t need to fixate on a target.
Our eye doctor places a scleral shell between the eyelids. The scleral shell is filled with saline and has a probe that lies in the fluid. The ultrasound measures the axial length through sound waves going through the fluid to the retina. This technique has its limitations.
The ultrasound measures the anatomical axial length instead of the optical focal length. The anatomical AL is always longer than the optical AL. To overcome this limitation, eye doctors embraced optical biometry.
Optical Biometry
Optical biometry is very accurate and precise when measuring the axial length. Optical biometry uses light to measure the optical axial length when you fixate on a target. The device sends infrared light into the eye and measures the light reflected from the retina. It measures the axial length and other anatomical features of the eye based on the pattern between the received and reflected light.
Optical biometry offers the best precision in axial length measurements, but it has its limitations too. Optical biometry does not work with patients who have deep cataracts. For these patients, our eye doctor will use ultrasound biometry.
Schedule an Appointment with Our Optometrist
If you need assistance managing your myopia, we can help. At Eye See in Lincolnshire, IL, we offer techniques to measure and diagnose your myopia so our optometrist can treat it. To learn more or to schedule an appointment, call us today.
