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Astigmatism Severity Scale | San Antonio LASIK Eye Surgery

Category: LASIK

Many people who suffer from nearsightedness, farsightedness, and/or astigmatism have been told they are not candidates for LASIK surgery. Thanks to modern technology, this may not be the case anymore. There have been great advancements in technology that have made it possible for people with all types of vision problems to benefit from this life-changing procedure. Here’s what you need to know about Lasik and astigmatism.


What are the Types and Severity of Astigmatism

Astigmatism is a vision error that occurs when the cornea (the clear, curved front surface of the eye) or the lens (the transparent structure behind the cornea that helps focus light on the retina) is curved more in one direction than in another, similar to the side of a football or the back of a spoon. This causes objects to appear blurry or stretched out. Astigmatism is a very common condition that affects people of all ages and can be treated with glasses or contact lenses, or fixed permanently with surgery. 


Astigmatism Severity Scale

An “astigmatism severity scale” is a system that eye doctors use to measure and describe how severe or pronounced an individual’s astigmatism is. Astigmatism causes light to focus on multiple points rather than just one. This can result in blurry or distorted vision.


The severity scale helps eye doctors understand the extent of this uneven curvature and how it affects a person’s vision. The scale typically involves measuring the degree of astigmatism in diopters, which is a unit of measurement. A higher number on the scale indicates a greater degree of astigmatism and a more noticeable visual distortion.


Using this scale, eye doctors can determine the appropriate treatment options, such as prescription glasses, contact lenses, or even surgical procedures, to help correct the astigmatism and improve the patient’s vision. The severity scale is an important tool in ensuring that individuals with astigmatism receive the most effective and tailored treatment for their specific visual needs.


How does the doctor determine astigmatism?

An astigmatism axis chart is a graphical representation that eye doctors use to help diagnose and describe the orientation of astigmatism in a person’s eye. The chart is usually a circular diagram that resembles a clock face, with numbers from 0 to 180 degrees along the edge. Each number represents a specific angle or axis. The purpose of this chart is to indicate the direction of the elongation or curvature of the cornea or lens that is causing the astigmatism.


When a person undergoes an eye exam, the eye doctor uses different lenses and tests to determine the axis of astigmatism. By rotating lenses and observing how they affect the clarity of the person’s vision, the doctor can pinpoint the exact axis of astigmatism in degrees. This information is crucial for surgical measurements that will correct the person’s astigmatism and provide clear vision with laser vision correction.


How Does LASIK Surgery Work? 

LASIK surgery works by reshaping the cornea so that light entering the eye is properly focused on the retina (the light-sensitive tissue at the back of the eye). The surgeon first creates a very thin ‘window’ in the cornea using a femtosecond laser (a highly precise laser that produces short pulses of energy). The small window is then opened so that the underlying corneal tissue can be reshaped with an excimer laser (a UV laser that vaporizes tissue). Finally, the window is closed back in place and allowed to heal. 


LASIK for Astigmatism 

LASIK surgery is a popular procedure for correcting astigmatism. LASIK works by changing the shape of the cornea, the clear outer layer of the eye. As a result, astigmatism is corrected and vision is improved. LASIK provides a long-term solution to astigmatism.


Simple Hyperopic Astigmatism

Simple hyperopic astigmatism is a type of vision condition where a person has two specific optical problems in their eye: hyperopia (farsightedness) and astigmatism. Let’s break down what each of these terms means:

Now, when someone has simple hyperopic astigmatism, it means they have both hyperopia and astigmatism, but astigmatism is the only significant optical aberration present. “Simple” in this context indicates that only one principal meridian (the most curved or most steeply curved axis of the cornea) has the issue. This condition is diagnosed through an eye exam, and sometimes refractive surgery is used to correct the combined effects of hyperopia and astigmatism, providing clear and comfortable vision at various distances.


Compound Myopic Astigmatism

Compound myopic astigmatism is a specific type of vision condition that affects the way light is focused on the retina in the eye. Let’s break down what this term means:

Now, when someone has compound myopic astigmatism, it means they have both myopia and astigmatism, and the principal meridians (the most curved or most steeply curved axes of the cornea) for both conditions are oriented in the same direction. In other words, the eye is nearsighted in two specific meridians that are perpendicular to each other, and the astigmatism further complicates the focusing of light, potentially causing more blurred or distorted vision.

Correcting compound myopic astigmatism with LASIK (Laser-Assisted in Situ Keratomileusis) is a surgical procedure that can provide effective and long-lasting vision correction.


Be sure to talk to one of our doctors about not only the benefits of LASIK, but also any risks of LASIK that may pertain to your individual needs and circumstances.


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