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Lazers

Optical quantum generators

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Laser that cuts inside the cornea: ReLEx procedure at the physical level

Reading time6 min
Views2K
The idea — to take and cut a lens in a transparent cornea — is not new. At first it was done manually, with a scalpel directly on the surface (difficult and very rough, with a sea of side effects). The first laser was used in 1979, then it was a pulsed infrared emitter with an effective pulse length of 4 nanoseconds.


Step 1: creating a plasma bubble, in fact — a microburst. Step 2: expansion of the shock and heat waves. Step 3: cavitation bubble (plasma expansion). Step 4: the formation of a parallel slice at the expense of several adjacent laser focus points.

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How to “sew up” the retina and should it be done?

Reading time9 min
Views1.8K
Imagine the situation — you live in peace, nothing hurts and does not blush, wear glasses or lenses, or do not use anything and see perfectly — and you accidentally get an appointment with an ophthalmologist. For example, because of conscription into the army, because of pregnancy, or just for a dispensary examination. And suddenly you will find out that your retina is “full of holes” or stretched and is about to break.

And they recommend you to “sew it on”. And you doubt — and this is exactly what you need? And how safe is it? But nothing bothers — then why? Or maybe they want to earn money on me? And the first thing you start is to read posts on the Internet, what a “independent” expert like Google will say.

And in the future everything depends on your discipline and attention to your own health. You can get to the ophthalmologist-laser specialist, who will be the last resort, and he will do preventive laser coagulation.

Or «forget it» for everything and continue to live as before — nothing bothers you. What is the risk?

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FAQ about laser correction ReLEx SMILE: yes, in Russia there is, but no, in Russia there isn’t

Reading time9 min
Views2.1K


— Are small-invasive laser vision correction operations done in Russia using the Small Incision Lenticule Extraction method?

Yes, about 10 years already. Every year, more and more at conferences of ophthalmologists, questions arise not at the level of “What is this?”, But at specific practical nuances of technology. VisuMax lasers exist in several clinics in Russia, but it is much less used under ReLEx SMILE than under femtoLASIK. Historically, it happened in Russia that this technology is little used in the central part and is actively used beyond the Urals.

— What is the story with licenses for specific operations?

Zeiss sells cones with licenses. A cone — a replacement part adjacent to the eye — is purchased with a license to use a laser procedure, usually in batches of 10 or 100 operations. For example, 10 cones and 10 licenses are received. Licenses are driven through the laser menu, and it allows you to use the appropriate cones for the appropriate program types. Licenses for SMILE separately, for femtoLASIK separately, for FLEX, rings and additional corrections are also separate licenses. Most manufacturers of femtosecond and some excimer lasers have a similar situation. Licenses for excimer operations are not needed, perhaps, except on models of about 5 years old and older.

— And you can not get such a license for SMILE?

Easily. Firstly, this module in the laser is as an expensive option, so the device itself without the SMILE option is cheaper. Secondly, if this option is available, then licenses to carry out the operation ReLEx SMILE can be acquired only after conducting 5–10 test runs on pig eyes, then performing at least 10 femtoLASIK operations on patients, then 50 FLEX operations, and only after that Buy a SMILE license for a specific surgeon.
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A couple more unobvious things that you might not be told before laser vision correction

Reading time13 min
Views1.1K

Today, without the «tin», as you asked

There is already a post about how the laser cuts by creating millions of cavitation bubbles in the cornea layer of the eye, and analyzing telemetry from the real operation in seconds with comments of the surgeon's actions.

Now FAQ about various related things


— If I look away while the laser is running, what will happen?

You simply will not work. In fact, immediately after anesthesia, the eye is pressed against a special pneumocapture. To blink at you too will not leave because of fixing (it is not long and not for long). The only moment where it is possible to seriously disrupt the course of the operation is to pull the head down strongly, pulling it out of the headrest by a serious willed effort. In this case, the operation will instantly stop. More precisely, it will stop even before the loss of capture (details below).

— How should an operating room be prepared?

In general — as a normal operating room, that is, a room with a clean area (air filtration, overpressure to prevent contamination from the outside after cleaning). It is important for the procedure that microparticles of dust flying in the air do not fall between the laser lens and the eye.
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