Side Cut and SMILE

Today, we’re going to talk about an important concept that frequently comes up when learning about SMILE and SMILE Pro vision correction procedures.

The topic of today’s post is “side cut.”

1. What is a Side Cut?

The VisuMax laser, developed by ZEISS, is the key device used in SMILE surgery. It enables the smooth extraction of the lenticule, which is at the core of the procedure. VisuMax incorporates various cutting-edge technologies specifically designed for SMILE surgery.

As we’ve explained before, two of these key technologies are “precision scanning” and today’s main topic, “side cut.”

A side cut is a crucial technique that allows for precise lenticule incision while minimizing unnecessary impact on surrounding tissue.

To safely separate the lenticule, it’s essential to cut its edges at a specific angle. This helps ensure smooth tissue separation during extraction while minimizing strain on other parts of the eye. If the lenticule’s edges become too thin, there is a risk of tearing or irregular detachment, which could negatively affect the vision recovery process.

Before lenticule extraction, it is also vital to clearly distinguish between its front and back surfaces. Failure to do so may prolong the surgery or potentially damage the corneal tissue. Ultimately, the side cut technology enhances the precision of lenticule incision, improves surgical stability, and plays a key role in ensuring a successful vision recovery.

2. Different Perspectives on Side Cuts

As SMILE surgery gains worldwide recognition as a leading lenticule extraction procedure, other surgical techniques for lenticule-based vision correction have also emerged. Some of these alternative techniques promote “safe vision correction without the need for a side cut.”

So, why do some argue that eliminating the side cut makes vision correction safer?

(1) Does the Side Cut Cause Halos and Glare?

There is no need for major concern regarding this claim.

So far, no concrete evidence or specific case studies have confirmed that the side cut causes visual disturbances such as halos or glare. Additionally, no official announcements have been made to support this theory.

On the contrary, the importance of the side cut in SMILE surgery has been well-documented in academic research.

▲ Source: Variation of Lenticule Thickness for SMILE in Low Myopia – Siedlecki, JRS, 2018

While research confirms that SMILE surgery is stable for low myopia cases, it is difficult to find documented cases of lenticule extraction surgeries performed for myopia below -3.00D outside of SMILE. This suggests that performing lenticule extraction surgery without a side cut presents significant challenges.

(2) Does the Side Cut Affect the Accuracy of Astigmatism Correction?

There is currently no scientific evidence or published research indicating that the side cut negatively impacts astigmatism correction. On the contrary, the effectiveness of ZEISS SMILE’s patented side cut technology has been validated in multiple studies.

▲ Source: Comparing Corneal HOAs in Corneal WG-TransPRK vs. SMILE – Kang, JCRS, 2018

To summarize the findings of this study, SMILE has demonstrated a 100% success rate in correcting astigmatism cases of 0.50D or lower.

ZEISS SMILE has already been performed in over 10 million cases worldwide, including 1.5 million cases in Korea alone. Furthermore, over 800 SCI-grade research papers have been published on this procedure, confirming its safety and efficacy.

The side cut technique is an exclusive, patented technology of ZEISS VisuMax. Because other vision correction devices cannot implement the side cut, their lenticule extraction techniques are unlikely to achieve the same clinical outcomes as VisuMax. Notably, the FDA approval of ZEISS SMILE in the U.S. further underscores the stability and reliability of its side cut technology.

Today, we explored the side cut, a key differentiating factor of ZEISS SMILE. Stay tuned for more informative content on vision correction procedures.

Thank you!