When a patient hears the diagnosis “astigmatism,” he feels alarmed that here is some serious eye disease has caught up with him. But astigmatism is not a disease that can be contracted suddenly, but a defectively constructed cornea or lens. This defect is hereditary and our lifestyle does not have the slightest influence on its development. Instead, we have an influence on getting rid of it and saving ourselves the trouble of choosing glasses or contact lenses.
Yes, astigmatism can be corrected with glasses or contact lenses, but…
Specificity of astigmatism
The peculiarity of astigmatism is that one is unable to catch visual acuity and has an impaired sense of space. Symptoms from the optical system can be accompanied by headaches and dizziness, burning and watery eyes and trouble concentrating.
First, astigmatism is a defect that either requires no correction at all or makes it very difficult to choose the right eyeglasses or contact lenses.
We can function quite well having minimal astigmatism – we just get used to seeing this way, not that way. Experts believe that astigmatism is such a common abnormality that it can be said to affect most people. In many cases, however, the changes in the cornea are so small that it does not significantly affect the quality of vision and does not require correction. If the astigmatism does not exceed 1.0 diopters, it usually does not require correction, but a higher one makes about 50% of patients feel such a significant impairment in the quality of vision and related comfort of daily functioning that they require ophthalmological assistance. And this is where the stairs begin….
There are many varieties and many classifications of astigmatism – you can find everything about it on our website.
The more complicated the astigmatism, the greater the difficulty in selecting corrective eyeglasses or contact lenses.
Of course, there are both spectacle lenses (cylindrical) and contact lenses (toric), created specifically to correct astigmatism, but it happens that the ophthalmologist is not able to choose the optimal correction for his patient. That is: objectively speaking, he offers the patient the best possible correction for his visual defect, but the patient subjectively feels no improvement in vision.
Second, astigmatism rarely occurs as a sole visual defect. It often accompanies myopia, for example, and then selecting lenses/lenses that are truly comfortable for the patient is even more difficult.
Let’s summarize: although, thanks to the current state of knowledge, all types of astigmatism easily lend themselves to diagnosis, it is still a considerable difficulty to select corrective glasses or contact lenses that are as comfortable as possible for the patient.
That’s why astigmatism is best targeted with a laser!
Laser correction of astigmatism
As many as 99% of astigmatism cases are laser-correctable defects. This is especially true when dealing with complicated, irregular astigmatism and/or accompanying other visual defects (myopia, hyperopia) or eye diseases (such as cataracts).
Astigmatism is scaled as follows:
- low – up to 1 cylindrical dioptres (usually does not require correction)
- medium – from 1 to 2 cylindrical diopters
- high – from 2 to 3 cylindrical diopters
- very high – more than 3 cylindrical diopters
As part of laser vision correction, it is possible to treat astigmatism up to about 6 diopters. If the patient also struggles with myopia or hyperopia, then both defects can be corrected during one treatment.
Laser correction of astigmatism is performed by methods:
- Femto-LASIK (All-Laser-LASIK): With a precision femtosecond laser, the surgeon makes a cut into the cornea, creating a thin flap 0.1 mm thick – a flap. He uses an excimer laser to reshape the previously exposed cornea for a few seconds, then the flap is closed back up; it attaches and forms a protective corneal barrier.
- LASIK (laser assisted in situ keratomileusis): a two-step technique; the cornea is incised with a scalpel (microkeratome), and then the corneal surface is modeled so that it can properly focus the image onto the retina.
- LASEK/PRK: The procedure involves either deflecting (LASEK) or removing (PRK) the upper cellular layer of the cornea (epithelium) and then appropriately reshaping the underlying corneal tissue with an excimer laser. The goal of the procedure is to properly model the central surface of the cornea with a laser beam so that it focuses the image precisely on the retinal surface.
When operating with lasers on eyes burdened with astigmatism, it is not necessary to put the patient under general anesthesia. The procedures are performed only with local anesthesia in the form of eye drops. After the operation, the patient stays in the post-operative room for about 2-3 hours.
If there are no contraindications, he can go home. He receives a full list of post-operative recommendations at his first post-operative check-up.
