Corneal Thickness and Laser Eye Surgery – What You Need to Know

corneal thickness

Corneal Thickness and Laser Eye Surgery – What You Need to Know

corneal thickness

Laser eye surgery has become a popular option for individuals looking to improve their vision permanently without the need for glasses or contact lenses. One important factor that plays a significant role in the success of laser eye surgery is corneal thickness. The cornea, which is the clear front surface of the eye, needs to have a certain thickness to ensure the procedure can be safely and effectively performed. Reading this blog till the end will let you explore the impact of corneal thickness on laser eye surgery and what you need to know before undergoing the procedure.

What Is Corneal Thickness?

Corneal thickness refers to the measurement of the cornea from the front surface to the back surface. Adequate corneal thickness is necessary to ensure that enough tissue can be safely removed to achieve the desired vision correction when refractive surgery is performed. If the cornea is too thin, there may not be enough tissue to remove, leading to an increased risk of complications. 

It is important to note that corneal thickness can vary among individuals. Factors such as age, genetics, and certain medical conditions can influence the thickness of the cornea. Therefore, it is crucial to undergo a thorough preoperative evaluation to determine if you are a suitable candidate for laser eye surgery based on your corneal thickness.

Impact of Corneal Thickness on Laser Eye Surgery

Corneal thickness is an essential aspect of laser eye surgery because the laser used during the procedure reshapes the cornea to correct vision problems such as nearsightedness, farsightedness, and astigmatism. If the cornea is too thin, there is an increased risk of complications such as corneal ectasia, which is a condition characterized by corneal thinning and bulging. Corneal ectasia can lead to distorted vision and may require additional treatments or even corneal transplant surgery to correct.

On the other hand, if the cornea is too thick, diseases such as endothelial dystrophy need to be ruled out.

Therefore, it is crucial to have a thorough understanding of your corneal thickness and its impact on the success of laser eye surgery. Your ophthalmologist will evaluate your corneal thickness during the preoperative evaluation.

How Is Corneal Thickness Measured?

Corneal thickness can be measured using a technique called pachymetry test that involves using a specialized instrument called a pachymeter to measure the thickness of the cornea. During the procedure, a small probe is gently placed on the cornea, and the thickness is measured in micrometers.

Pachymetry test is a quick and painless procedure that provides valuable information about the corneal thickness. It allows the ophthalmologist to determine if the cornea has adequate thickness for laser eye surgery and helps in planning the appropriate treatment.

Laser Eye Surgery Options and Corneal Thickness Requirements

There are different types of laser eye surgery options available, including SILK, SMILE, Contoura Vision, LASIK, and PRK. Each procedure has specific average cornea thickness requirements to ensure safety and effectiveness.

SILK, SMILE, and LASIK, which are the most commonly performed laser eye surgery, typically requires an average corneal thickness of at least 500 micrometers. PRK, another popular procedure, may be suitable for individuals with thinner corneas, but it is important to consult with your ophthalmologist to determine if PRK is the right option for you. 

What If I Have Thin Corneas?

If you have thin corneas, it is important not to lose hope. While SILK, SMILE, and LASIK may not be a suitable option for individuals with thin corneas, there are alternative procedures such as PRK or ICL suitable for you or other people with thin average cornea thickness.

PRK involves removing the outermost layer of the cornea (epithelium) before reshaping the underlying tissue with the laser. This procedure does not require the creation of a corneal flap or lenticule, making it a viable option for individuals with thin corneas.

ICL implantation does not involve the cornea and is a safe and effective refractive procedure of choice in individuals with thin corneas and high power.

Preoperative Evaluation 

Before undergoing laser eye surgery, you will undergo a thorough preoperative evaluation called pachymetry. This evaluation will include a comprehensive eye examination, including measurements of your corneal thickness, refraction, and assessment of your overall eye health.

During the evaluation, your ophthalmologist will determine if you are a suitable candidate for laser eye surgery based on various factors, including your corneal thickness. They will assess your corneal thickness to ensure it meets the requirements for the specific laser eye surgery option you are considering.

In addition to corneal thickness, other factors such as the health of your eyes, the stability of your prescription, and the absence of certain eye conditions will also be evaluated during the pre-operative assessment.

Potential Risks and Complications

Like any surgical procedure, laser eye surgery carries some risks and potential complications. Understanding these risks is crucial in making an informed decision about the procedure.

Some potential risks and complications associated with laser eye surgery include dry eyes, glare or halos around lights, fluctuations in vision, undercorrection or overcorrection of the vision problem, infection, corneal haze, and corneal ectasia.

However, it is important to note that the majority of individuals who undergo laser eye surgery achieve significant improvements in their vision and are satisfied with the results. 

Advancements in Technology

Advancements in technology have greatly improved the safety and effectiveness of laser eye surgery. With the development of advanced laser systems and diagnostic tools, ophthalmologists can now perform laser eye surgery with more precision and accuracy.

For individuals with thinner corneas, advancements such as PRK, SILK, and SMILE have opened up new possibilities for vision correction. These procedures offer alternative options for individuals who may not be suitable candidates for LASIK or Contoura Vision.


Corneal thickness plays a crucial role in the success, safety, and effectiveness of laser eye surgery. It is important to undergo a thorough preoperative evaluation to determine if you are a suitable candidate for laser eye surgery based on your corneal thickness.


What is normal corneal thickness?

Normal or average corneal thickness is approximately 540-550 micrometers (µm).

What does a thickened cornea mean?

A thickened cornea may indicate conditions such as corneal edema, but it can also be a natural variation without disease.

What is the 90% thickness of cornea?

90% of the corneal thickness would be approximately 486-495 micrometers (µm), given a normal corneal thickness of 540-550 µm.

What is the disease of corneal thickness?

Keratoconus is a disease where the cornea thins and bulges outward into a cone shape.

What if I have thin corneas? Are there alternative vision correction options?

Yes, alternative vision correction options include photorefractive keratectomy (PRK), and implantable contact lenses (ICL).

What happens during a consultation to determine LASIK candidacy?

During a LASIK consultation, the eye doctor will perform a comprehensive eye exam, including measurements of corneal thickness, shape, and overall eye health, to determine if you are a suitable candidate for LASIK surgery.

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