Lens Implantation Surgery for Correcting High Astigmatism

Many individuals who desire clear vision without glasses or contact lenses find themselves hesitant due to high astigmatism or severe myopia. For these cases, lens implantation surgery is gaining recognition as a vision correction method that can address both astigmatism and myopia simultaneously. It is becoming a popular option, especially for patients with severe astigmatism.

Today, we will delve into a detailed understanding of high astigmatism, the principles of lens implantation surgery, its procedure, and the essential factors to consider during the process.

1. What Are Myopia, Astigmatism, and High Astigmatism?

▲ Overseas Studies on Refractive and Axial Parameters

To address vision problems effectively, it is crucial to understand their root causes. While myopia and astigmatism are common vision impairments, few people clearly understand the difference between them. Let’s take a closer look at myopia, astigmatism, and high astigmatism.

(1) Myopia

Myopia refers to a condition where nearby objects appear clear, but distant objects appear blurry. This occurs because the eyeball is elongated, causing light to focus in front of the retina instead of directly on it.

▲ Graph of Myopia Prevalence Increase (2000–2050)

According to the WHO’s “World Vision Report,” over 90% of adolescents in South Korea experience myopia. Each year, more than 1.2 million people visit hospitals due to myopia. Statistics from 2018 reveal that out of approximately 1.206 million myopia patients, about 37% were teenagers.

(2) Astigmatism

▲ Study on Changes in Astigmatism Prevalence by Age

Astigmatism is a condition caused by an irregularly shaped cornea or lens, which prevents light from focusing evenly on the retina. This leads to blurred or distorted vision at all distances.

Astigmatism occurs when the cornea or lens is unevenly curved, causing light to scatter into multiple focal points instead of converging into one. Due to its directional nature, astigmatism results in misfocused vision along specific axes. Severe astigmatism can lead to eye strain and visual distortion.

(3) High Astigmatism

High astigmatism refers to cases where the measurement exceeds -3 diopters. This condition is challenging to correct with standard glasses or contact lenses, and conventional laser vision correction procedures often have limitations in addressing it.

2. Principles and Types of Lens Implantation Surgery

Now, let’s dive into the details of lens implantation surgery. In previous posts, we focused on SMILE and SMILE Pro among various vision correction procedures. However, for individuals who cannot opt for these procedures due to specific conditions, lens implantation surgery offers an excellent alternative.

▲ High-Frequency Ultrasound Scan Image of the Anterior Segment with IOL

Lens implant surgery corrects vision by inserting a special lens into the eye without cutting the cornea. It utilizes biocompatible lenses and is classified into two main types based on the insertion location:

(1) Anterior Chamber Lens Implantation

This method involves inserting the lens in front of the iris, directly attaching it to the iris. It is highly effective for astigmatism correction, as the lens can be precisely adjusted according to the astigmatic axis. With minimal incision, recovery is quick, and the risk of cataracts or glaucoma is reduced. However, regular follow-ups are necessary post-surgery, as endothelial cell loss may occur.

(2) Posterior Chamber Lens Implantation

In this method, the lens is placed behind the iris and in front of the natural lens, offering high stability and long-term effectiveness. It does not require an iridotomy, enabling same-day surgery, and is resilient against external impacts. Using toric lenses allows simultaneous correction of myopia and astigmatism, making it a highly efficient option. Since the cornea is not cut, the risk of dry eye syndrome or regression of myopia is minimized.

To correct severe astigmatism through lens implantation surgery, it is crucial to use anterior segment OCT equipment to analyze the eye’s structure in detail. This ensures the selection of the most suitable lens size for the patient’s eyes. Additionally, the expertise of certified and experienced surgeons is essential for successful surgery.

3. Lens Implantation Surgery Q&A

Here are answers to some common questions from patients considering lens implantation surgery:

Q1. Can all types of astigmatism be corrected with lens implantation surgery?

Yes, lens implantation surgery effectively corrects high astigmatism using toric lenses. However, there is a 1–2% chance that the lens may rotate slightly after implantation, which can affect the correction results.

Q2. Is lens implantation surgery possible for patients who have had LASIK and need further correction?

Yes, it is possible. Since lens implantation surgery does not involve cutting the cornea, it can be safely performed even on patients with thin corneas due to prior LASIK or LASEK procedures. It is also suitable for patients with keratoconus or those seeking presbyopia correction.

Q3. How long does it take to recover vision after surgery?

Lens implantation surgery has a relatively short recovery time. Most patients experience clear vision immediately after the procedure and can return to daily activities within 1–2 days.

Q4. Is the procedure painful?

The surgery is performed under local anesthesia, and most patients report no pain during the procedure. Post-surgery, patients may experience slight discomfort or a foreign body sensation, which usually subsides within a few days.

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