LASEK for High Astigmatism: Is It a Safe Option?

If you’ve been told you have high astigmatism, you may already know that not every vision correction surgery is suitable for you. Some patients are disappointed to learn that LASIK the most well-known laser procedure isn’t always recommended when the corneal shape or thickness falls outside certain limits.

But that doesn’t necessarily mean laser eye surgery is off the table. For many people with high astigmatism, LASEK (Laser-Assisted Sub-Epithelial Keratectomy) offers a safer, more customised alternative.

In this article, we’ll explore how LASEK works, how effectively it can correct high astigmatism, and what you can expect in terms of safety, recovery, and long-term outcomes helping you decide if it could be the right solution for your vision.

Understanding Astigmatism

Astigmatism is a common refractive error that occurs when the cornea (the front surface of your eye) or lens inside the eye is irregularly shaped.

Instead of being perfectly round, the cornea is slightly curved more like a rugby ball than a football. This uneven curvature causes light entering the eye to focus on multiple points rather than one, leading to blurred or distorted vision at all distances.

You may notice:

  • Blurry or fuzzy vision
  • Eye strain or headaches
  • Difficulty seeing at night
  • Frequent changes in glasses prescription

Astigmatism is measured in dioptres. Mild cases may be easily corrected with glasses or contact lenses, but higher levels typically above 3.00 dioptres require more advanced correction methods, such as LASEK.

What Is LASEK?

LASEK (Laser-Assisted Sub-Epithelial Keratectomy) is a surface-based laser eye surgery technique used to correct refractive errors, including myopia (short-sightedness), hyperopia (long-sightedness), and astigmatism.

It’s similar to PRK (Photorefractive Keratectomy) and shares some principles with LASIK, but with one major difference no corneal flap is created.

Instead, LASEK gently loosens and preserves the thin top layer of the cornea (the epithelium), moves it aside, and then uses an excimer laser to reshape the underlying tissue. The epithelial layer is then repositioned to aid healing.

This approach makes LASEK particularly suitable for people who:

  • Have thin or irregular corneas
  • Engage in contact sports or jobs with risk of eye trauma
  • Have high astigmatism that requires more precise surface correction

Why LASIK Isn’t Always Suitable for High Astigmatism

LASIK remains one of the most popular laser vision correction procedures. It involves creating a small flap in the cornea, reshaping the underlying tissue with a laser, and replacing the flap.

However, in cases of high astigmatism or thin corneas, LASIK can present certain challenges:

  1. Corneal Stability: Removing too much tissue can weaken the cornea, increasing the risk of ectasia (bulging or distortion).
  2. Flap Complications: In thinner corneas, flap creation may compromise structural strength.
  3. Precision Limits: High astigmatism may require more tissue removal than LASIK can safely accommodate.

LASEK avoids these concerns by treating the surface of the cornea without creating a flap making it a safer alternative for patients who are otherwise unsuitable for LASIK.

How LASEK Corrects Astigmatism

During LASEK, the surgeon reshapes the corneal surface using a computer-guided excimer laser. The laser removes microscopic layers of tissue to create a more regular curvature, allowing light to focus correctly on the retina.

For astigmatism, the laser specifically targets the steeper and flatter meridians of the cornea, smoothing out irregularities to achieve balanced focusing power.

Because of its customisable treatment zones, LASEK can correct even complex astigmatic patterns with high precision.

The degree of correction possible depends on:

  • The thickness and shape of your cornea
  • The severity of your astigmatism
  • The health of your tear film and ocular surface

Modern LASEK technology, guided by wavefront mapping and topography-guided algorithms, allows for extremely accurate reshaping that was not possible with earlier generations of laser surgery.

How Much Astigmatism Can LASEK Correct?

Every patient’s eye is unique, but in general, LASEK can safely correct up to:

  • 6 dioptres of myopia
  • 3 dioptres of hyperopia
  • Up to 5 dioptres of astigmatism (in select cases, even slightly higher)

These limits depend on individual corneal characteristics and the laser technology used. At modern eye clinics equipped with advanced excimer systems, results for high astigmatism are significantly improved compared to older techniques.

The LASEK Procedure: Step-by-Step

Here’s what typically happens during LASEK surgery:

  1. Preparation: You’ll receive anaesthetic eye drops to numb the surface of your eyes.
  2. Epithelial Loosening: The surgeon applies a dilute alcohol solution to loosen the thin top layer of the cornea.
  3. Layer Removal: The epithelium is gently moved aside to expose the underlying tissue.
  4. Laser Reshaping: The excimer laser precisely reshapes the cornea according to your customised treatment plan.
  5. Repositioning: The epithelial layer is placed back onto the eye and a protective contact lens is applied.

The procedure typically takes 10–15 minutes per eye and is performed under topical anaesthesia no injections or stitches required.

Recovery After LASEK

Unlike LASIK, where vision improves rapidly within 24–48 hours, recovery after LASEK is slightly longer. That’s because the surface cells (epithelium) need time to heal.

Typical recovery timeline:

  • Days 1–3: Eyes may feel gritty, watery, or sensitive to light.
  • Days 4–7: Vision begins to stabilise as the epithelium heals.
  • Weeks 2–4: Blurriness gradually clears, and visual sharpness improves.
  • 3–6 months: Final vision results achieved as the cornea remodels and refines focus.

Most patients can resume normal activities within one week, though complete healing and optimal clarity take longer.

Safety of LASEK for High Astigmatism

When performed by an experienced ophthalmic surgeon, LASEK is a safe and proven method for correcting high astigmatism. It has been used for over two decades, with continual improvements in laser accuracy and post-operative comfort.

Key safety advantages:

  1. No corneal flap: Eliminates risk of flap complications seen in LASIK.
  2. Preserves corneal thickness: Ideal for thinner or irregular corneas.
  3. Lower risk of ectasia: Surface ablation techniques leave deeper corneal layers untouched.
  4. Precision for complex prescriptions: Advanced mapping ensures even correction of irregular astigmatism.

Potential side effects (usually temporary):

  • Mild discomfort or light sensitivity during healing
  • Dryness or slight blurriness in early recovery
  • Rarely, minor haze (usually preventable with medicated drops)

Serious complications are very uncommon when proper screening and aftercare are followed.

LASEK vs LASIK vs PRK: Comparing Your Options

When you’re considering vision correction surgery, you might be wondering how LASEK, LASIK, and PRK compare. Each option has its own benefits depending on your eyes and lifestyle.

LASEK doesn’t involve creating a corneal flap, which makes it a safer choice if you have thinner corneas or a higher prescription. Recovery usually takes about 5–7 days, and you may feel only mild discomfort. Its long-term results are excellent, and the risk of complications like ectasia is very low.

LASIK, on the other hand, does involve a corneal flap. If your corneas are of average thickness, LASIK can be a great option because it usually gives you a faster recovery—often just 1–2 days—with minimal discomfort. Its long-term outcomes are also excellent, though the risk of ectasia is slightly higher than with LASEK or PRK.

PRK avoids the corneal flap too, making it a solid choice if you lead an active lifestyle or participate in contact sports. Recovery tends to take a bit longer, around 7–10 days, and you may experience moderate discomfort. Like the other procedures, its long-term results are excellent, and the risk of complications is very low.

In short, if you want quicker recovery, LASIK might suit you best. But if safety and suitability for thinner corneas or higher prescriptions matter more, LASEK could be the better choice. PRK is ideal if you want to stay active without worrying about a corneal flap.

Can LASEK Fully Correct High Astigmatism?

In most cases, yes. LASEK can reduce or eliminate dependence on glasses and contact lenses even in patients with high astigmatism. However, results vary depending on:

  • The initial degree of astigmatism
  • The uniformity of corneal healing
  • Individual response to laser treatment

Some patients may still require mild prescription lenses for specific activities, such as night driving or reading, but overall vision quality improves dramatically.

Modern Technology Enhancing Precision

Recent innovations have made LASEK more effective and comfortable than ever before.

  1. Wavefront-Guided Technology

This maps the unique optical imperfections of your eye, allowing highly personalised laser corrections beyond standard prescriptions.

  1. Topography-Guided LASEK

By mapping corneal curvature in detail, this method corrects irregular astigmatism and enhances optical quality.

  1. Advanced Cooling and Eye-Tracking Systems

Modern lasers continuously adjust for micro-movements, ensuring perfect accuracy during treatment.

Together, these advancements make LASEK a predictable and safe solution even for complex refractive cases.

Patient Experience and Outcomes

Studies consistently show that patients with high astigmatism who undergo LASEK report:

  • Clearer distance and near vision
  • Improved contrast and night-time clarity
  • High satisfaction rates with long-term stability

Because LASEK preserves more of the natural corneal tissue, results tend to remain stable for many years without regression.

Who Is a Good Candidate for LASEK?

You may be suitable for LASEK if you:

  • Have high astigmatism that cannot be safely corrected with LASIK
  • Have thin or irregular corneas
  • Lead an active lifestyle or play contact sports
  • Want a long-term, low-risk vision correction solution

You may not be suitable if you:

  • Have unstable prescriptions (changes in last 12 months)
  • Have keratoconus or other corneal disorders
  • Are pregnant or breastfeeding
  • Have severe dry eye or autoimmune disease

A thorough eye assessment, including corneal topography, pachymetry, and tear film testing, is essential to confirm suitability.

How to Prepare for LASEK Surgery

Preparation is simple but important for ensuring a smooth procedure and recovery:

  • Stop wearing contact lenses 1–2 weeks before your consultation.
  • Avoid eye makeup and lotions on the day of surgery.
  • Arrange for someone to accompany you home after the procedure.
  • Discuss all medications and supplements with your surgeon.

Your ophthalmologist will guide you through every step and provide detailed aftercare instructions tailored to your eyes.

Recovery and Aftercare

After LASEK, you’ll use medicated eye drops to prevent infection, control inflammation, and promote healing. The protective contact lens is usually removed after 4–5 days.

You’ll attend several follow-up visits to monitor healing and visual improvement. Most patients can resume desk work within a week and return to full activities including exercise after 2–3 weeks.

Protecting your eyes from UV light and using artificial tears will further enhance recovery and comfort.

How Safe Is LASEK Long-Term?

LASEK has one of the best long-term safety profiles among laser vision correction methods. Studies show low rates of regression and complications even a decade after surgery.

Because the deeper layers of the cornea remain untouched, the structure of your eye stays strong, reducing the risk of post-surgical ectasia or distortion.

Why Choose a Specialist Clinic

Choosing the right clinic is as important as the surgery itself. Look for:

  • Experienced refractive surgeons with proven expertise in surface ablation
  • Access to wavefront and topography-guided lasers
  • Comprehensive pre-operative testing and aftercare

At Eye Clinic London, your suitability for Lasek surgery in London is assessed through advanced diagnostics, ensuring your procedure is both safe and precisely tailored to your unique vision needs.

FAQs:

  1. Will LASEK completely correct my high astigmatism?
    You can expect LASEK to significantly reduce or even eliminate your dependence on glasses and contact lenses, even if your astigmatism is high. The exact outcome depends on how severe your astigmatism is, how evenly your cornea heals, and how your eyes respond to the laser treatment. In some cases, you may still need mild prescription lenses for specific tasks, like driving at night or reading fine print, but your overall vision should improve dramatically.
  2. How long does it take to recover after LASEK?
    Recovery after LASEK is a bit slower than LASIK because your epithelial layer needs time to heal. In the first few days, your eyes may feel gritty or watery, and you might be sensitive to light. Around the fourth to seventh day, your vision begins to stabilise, and by two to four weeks, blurriness usually clears, allowing sharper focus. Full visual refinement can take up to three to six months as your cornea remodels and adjusts, but most daily activities can be resumed within a week.
  3. Is LASEK painful?
    You shouldn’t expect significant pain during the procedure because anaesthetic drops numb your eyes completely. During the recovery period, mild discomfort is common, often described as a gritty or scratchy feeling. Light sensitivity and occasional tearing may occur, but these symptoms gradually ease as your epithelial layer heals, and most patients find over-the-counter or prescribed eye drops sufficient to manage any discomfort.
  4. How does LASEK compare with LASIK for someone with high astigmatism?
    If you have high astigmatism or thinner corneas, LASIK may not be ideal because creating a corneal flap can weaken the structural integrity of your eye and limit how much tissue can safely be removed. LASEK avoids these concerns entirely by reshaping the surface of the cornea without a flap, offering a safer alternative while still providing precise correction. While LASIK gives faster recovery, LASEK is better suited for those whose corneal characteristics require a gentler approach.
  5. Can LASEK correct astigmatism that is irregular or complex?
    Yes, modern LASEK technology is highly advanced and can handle even irregular astigmatism patterns. The laser reshapes the cornea according to detailed maps of your eye, targeting both the steeper and flatter meridians to achieve balanced focusing. With wavefront-guided and topography-guided systems, your surgeon can create a highly personalised treatment plan that corrects complex optical imperfections, giving you sharper, more stable vision than older laser techniques could achieve.
  6. How safe is LASEK for long-term vision?
    LASEK has an excellent long-term safety record. Because the deeper layers of your cornea are left untouched, your eye retains its structural strength, reducing the risk of post-surgical complications like ectasia. Studies show that vision stability and clarity remain high even a decade after the procedure, especially when the surgery is performed by an experienced ophthalmic surgeon and proper aftercare is followed.
  7. Will I need to take special precautions after LASEK?
    During the initial healing period, it’s important to follow your surgeon’s instructions carefully. You’ll need to use medicated drops to prevent infection and promote healing, avoid rubbing your eyes, and protect them from UV exposure. The protective contact lens placed during surgery is usually removed after four to five days. Once your eyes start stabilising, you can gradually resume normal activities, but keeping up with artificial tears and UV protection helps maintain comfort and optimal results.
  8. Am I a good candidate for LASEK?
    You may be a good candidate if your astigmatism is too high or your corneas are too thin for LASIK. LASEK is also ideal if you lead an active lifestyle or participate in contact sports, because there’s no corneal flap that could be disrupted. However, you might not be suitable if your prescription is still changing, if you have keratoconus or other corneal disorders, or if you have severe dry eye or certain autoimmune conditions. A comprehensive assessment including corneal mapping and tear film evaluation will help your surgeon determine if LASEK is right for you.
  9. How long does the LASEK procedure take?
    The procedure itself is relatively quick, typically lasting 10 to 15 minutes per eye. You’ll receive numbing drops, and your surgeon will carefully loosen and move aside the top layer of your cornea before reshaping the underlying tissue with the laser. Once the laser work is complete, the epithelial layer is repositioned and a protective contact lens is applied. You remain awake throughout the procedure, and no stitches or injections are required.
  10. Can LASEK results change over time?
    While most patients experience stable vision long-term, your eyes can still change naturally with age. Slight regression is possible, especially if your astigmatism was extremely high, but advances in laser mapping and personalised treatment reduce this risk. Regular eye check-ups will help monitor any changes, and enhancements can sometimes be performed if needed to maintain optimal vision quality.

Final Thought: Clear Vision Without Compromise

If you’ve been told you’re not a candidate for LASIK because of high astigmatism or thinner corneas, LASEK could be the alternative that finally gives you the visual freedom you’ve been hoping for. It combines precision, safety, and long-term stability all without compromising the health or strength of your cornea.

Choosing an experienced specialist is the key to achieving the best results. At Eye Clinic London, every patient’s treatment plan is tailored using advanced diagnostic mapping and the latest surface laser technology to ensure safe and predictable correction.

If you’re considering LASEK surgery in London, you can get in touch with us at Eye Clinic London to find out whether this treatment is the right option for your vision needs.

References:

  1. Kuryan, J., et al., 2017. Laser-assisted subepithelial keratectomy (LASEK) versus… (comparative study) https://www.ncbi.nlm.nih.gov/articles/PMC5408355/
  2. Ning, J., et al., 2024. Surface ablation laser surgery: Bibliometric and visualised analysis over 20 years. https://www.ncbi.nlm.nih.gov/articles/PMC11557019/
  3. de Ortueta, D. & Arba-Mosquera, S., 2025. The Impact of Preoperative Corneal Epithelial Refraction Toricity on Transepithelial Photorefractive Keratectomy for the Treatment of Hyperopia or Mixed Astigmatism. https://www.mdpi.com/2411-5150/9/3/57
  4. Shahinian Jr, L., et al. (2002) “Laser-assisted subepithelial keratectomy for low to high myopia and astigmatism.” Journal Name, 121(60801), p.15. https://pubmed.ncbi.nlm.nih.gov/12160801/
  5. Reitblat, O., et al. (2021) “Refractive outcomes of high-magnitude astigmatism correction: FS-LASIK vs T-PRK.” Journal Name, 33295217 https://pubmed.ncbi.nlm.nih.gov/33295217/