How does laser eye surgery work? - Dan Reinstein

Summary

In 1948, Jose Ignacio Barraquer Moner developed keratomileusis, a pioneering eye surgery that carved the cornea into the correct shape to correct refractive errors like myopia, hyperopia, and astigmatism. Modern advancements have led to LASIK, using precise excimer lasers for non-invasive corneal sculpting. Techniques like SMILE and Laser Blended Vision further refine vision correction, promising a future where glasses may become obsolete.

Takeaways

• 👨‍⚕️ Jose Ignacio Barraquer Moner, a Spanish ophthalmologist, invented a surgical procedure to correct vision without glasses.
• 🔪 The original procedure, keratomileusis, involved cutting the cornea, freezing it, shaping it with a lathe, and sewing it back on.
• ❄️ Barraquer used liquid nitrogen to freeze the cornea, which was then ground into the necessary shape to correct the patient's vision.
• 👁️ Keratomileusis corrects refractive errors, which are imperfections in the eye's ability to focus light on the retina.
• 🌐 Refractive errors include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia (age-related focusing issues).
• 🤓 Glasses and contact lenses traditionally correct refractive errors by bending light, but Barraquer's surgery aimed to alter the cornea's shape directly.
• 💡 Modern eye surgeons use less invasive tools like excimer lasers for corrective laser eye surgery, which is more precise and safer.
• 👓 LASIK (laser in-situ keratomileusis) is a modern procedure that carves a patient's contact lens prescription onto their cornea.
• 🏥 The LASIK process involves creating a thin flap on the cornea, using a laser to reshape the cornea, and then allowing the flap to reseal.
• 🌟 SMILE (Small Incision Lenticule Extraction) is an advanced technique that allows surgeons to sculpt the cornea through even smaller incisions.
• 👓 Laser Blended Vision is a technique that adjusts one eye for distance vision and the other for close-up vision, helping patients see clearly at all distances.

Q & A

Who was Jose Ignacio Barraquer Moner and what was his contribution to ophthalmology?

Jose Ignacio Barraquer Moner was a Spanish ophthalmologist who, in 1948, devised a surgical procedure to correct refractive errors by altering the shape of the cornea itself, without relying on external aids like glasses or contact lenses.

What was the name of the procedure Barraquer developed, and what does it mean?

Barraquer called the procedure 'keratomileusis', which is derived from the Greek words for 'carving' and 'cornea'. It involved cutting off the front of the cornea, shaping it with a miniature lathe, and then sewing it back onto the eye.

What are refractive errors and how do they impair vision?

Refractive errors are imperfections in the way the eye focuses incoming light. They can cause light to be focused in front of, behind, or at two different distances from the retina, leading to blurry vision.

How does myopia or short-sightedness affect the eye's ability to focus light?

In people with myopia, the cornea is steep and focuses light just short of the retina, resulting in distant objects appearing blurry.

What is hyperopia and how does it differ from myopia?

Hyperopia, or far-sightedness, is the opposite of myopia. In hyperopia, light is focused too far beyond the retina, making close objects appear blurry.

What is astigmatism and how does it cause blurry vision?

Astigmatism occurs when the cornea has two different curvatures, causing light to focus at two different distances and resulting in blurry vision at all distances.

What is presbyopia and how does it affect vision as we age?

Presbyopia is the age-related decline in the eye's ability to focus on close objects. It occurs as the proteins in the lens age and increase its size, making it difficult to change shape and shift focus.

How does corrective laser eye surgery, such as LASIK, work to correct refractive errors?

LASIK uses an excimer laser to sculpt the cornea into the correct shape by separating a thin layer from the front of the cornea, then reshaping the exposed corneal bed, and finally allowing the flap to reseal.

What is photoablation and how is it used in laser eye surgery?

Photoablation is a technique used in laser eye surgery that allows the laser to evaporate organic tissue without overheating surrounding eye tissue, enabling ultra-fine incisions to be made safely.

What is the SMILE technique and how does it differ from LASIK?

SMILE (Small Incision Lenticule Extraction) is a technique that enables surgeons to sculpt the cornea through even smaller incisions than LASIK, further reducing recovery time and potentially minimizing complications.

What is Laser Blended Vision and how does it help with aging eyes?

Laser Blended Vision is a technique that adjusts one eye for slightly better distance vision and the other for better close-range vision, allowing most patients to merge their vision and work together at all distances.

What are the potential risks associated with LASIK surgery?

Some patients may experience slightly blurred vision that cannot be corrected by glasses, but the technique is considered relatively safe, with risks comparable to wearing daily disposable contact lenses for one year.