lasik new york

Development of technology

In 1960 he developed the first microkeratome, a special automatic knife, cut off the eye's surface a thin layer of the cornea and Bowman's membrane. Microkeratome allows batch of cut thickness corneal flap, or flap. Corneal flap is not completely cut off, but remains thin isthmus, usually to the nasal side. After the cut, no corneal flap is lifted and thus gain access to the inner layers of the cornea and the ability to produce these layers of influence. After that, cut corneal flap back into place. Sheared flap adheres immediately, and then grows very rapidly. The procedure for creating the corneal flap was called keratomileusis.

In 1981, researcher Rangasvani Srinivason discovered that an ultraviolet excimer laser capable of cutting the living tissue without damaging surrounding tissue at high temperatures. At the same time the usual green laser produced rough incisions. UV excimer laser cut living tissue very carefully. Rangasvani Srinivason procedure called cold vaporization of tissues, "ablative fotodekompozitsiey" and in 1983 a new partnership with ophthalmologists to improve the procedure and its application to impact on the cornea.

By 1991, technology had been successfully formed and operated the first patients in the U.S. and Germany.

The first LASIK surgery in Russia and one of the world's first was held in December 1990, an academician, Professor Igor Borisovich Medvedev, founded in 1999, Eye Surgery Center in Moscow.
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Improving technology

Since the first surgery technology has advanced. In view of the natural improvement of instrumentation, development of computer technology, currently used by more accurate and faster lasers than in 1990 and more sophisticated devices for diagnosis of view.
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Fully Laser LASIK

To replace the mechanical microkeratome started to use a femtosecond laser, which allows to create corneal flap using an infrared laser beam, this gives a more subtle and flavorful cut. Because of this, LASIK is possible as a combination of mechanical and laser effects, and, in the case of femtosecond laser - fully laser surgery, also called the Fully Laser LASIK (100% Laser LASIK) or FemtoSuperLasik. Femtosecond laser - a predictable accuracy, and unlimited possibilities for modeling of the corneal flap, the possibility of implantation of intrastromal rings and fiber plastic cornea. The laser allows you to create uniformly thin, "flat" corneal flap, completely controlling the diameter, thickness, alignment, and morphology with minimal disruption of architecture and biomechanics of the corneal stroma. During operation, an infrared femtosecond laser is focused at any desired depth in layers of the cornea, creating microscopic bubbles in the layers of the cornea. Thus there is a high-precision and gentle separation of the corneal flap. After creating a layer of bubbles, created corneal flap is separated minor mechanical action.
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Super LASIK

The "Superlasik" may include the use of a femtosecond laser for better separation of the corneal flap, but the essence is to eliminate higher-order aberrations. Aberration (optics of the eye disorders) may be the first order (associated with strabismus), second order (nearsightedness, farsightedness, astigmatism). Initial treatment yielded the second-order axisymmetric aberrations (nearsightedness and farsightedness), and then, using an oval laser beam - to treat steel and astigmatism. Higher-order aberrations are measured using a special high-precision instrument - aberrometer. It allows you to identify the aberration, not only related to the cornea, but also with other elements of the eye optics.

The purpose of Super LASIK - closer eye optics to the theoretical ideal. Even people with "normal" vision still has higher-order aberrations, so they have the eye optics is also not ideal.

Development of modern technology, a breakthrough in improving the equipment used in ophthalmology, to date makes it easy to diagnose higher-order aberrations, but also to correct them. Possibility of simultaneous correction of aberrations as the lowest and the highest order, has led to the concept of "superzreniya. This means that as a result of the maximum correction of optical distortions of the human eye is "optical device" improved accuracy, with visual acuity than the standard rate of 100%, reaching a level of 120 to 200%, in rare cases - and more. This increases the quality and post-operative vision (vision in different lighting conditions, at dusk, the bright glare, etc.).

To date, the clinic involved in the correction of higher order aberrations are geared to the diagnosis and correction of the total aberration of the eye, that is, distortions caused by all over the refractive media of the eye cornea to the retina itself.

However, it should be noted that, in general, the wave aberrations of the eye - the quantity rather unstable. Its changes are related to pupil size, patient age, condition of accommodation, changes in the vitreous body, retina, etc. Consequently, the prospect of such an approach to the correction of wavefront aberrations somewhat questionable.

Most constant, unchanged over the life source of the wave aberrations of the eye is the cornea. Following this promise, the German company was founded SCHWIND complex equipment, including equipment for the diagnosis of an isolated wavefront corneal KERATRON, objective aberrometry all eyes ABERROMETER and laser installation EZIRIS (related computer software with diagnostic equipment) for the correction of aberrations (such as lower and higher order ). This technology vision correction and has been called "optimized LASIK», aka "Super LASIK».

These measurements aberrometer processed in a special computer program that simulates a personalized ablation algorithm (ie the work of an excimer laser), allowing for the wavefront of the cornea, from a range of individual parameters of the patient's eye, and depending on the anticipated result of the operation. The developed algorithm is transferred to the computer of the excimer laser. The course of the operation itself hardly differs from the traditional method of LASIK. The difference lies in the software itself ablation (ie, the program of the laser).
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The operation

Step 1 - creating the corneal flap. Includes the use of a unique automated microsurgical instrument - microkeratome, which gives access to the middle layers of corneal tissue. This procedure takes 2-5 seconds and is absolutely painless. Shaped flap in the surface layers of the cornea with a diameter of 8 mm, but not entirely, on the one hand still attached to the cornea, so that after the second stage the flap back into place. The resulting flap is the same thickness throughout its length. Rather than a mechanical microkeratome is also possible to use femtosecond laser - even more gentle and precise tool.

Stage 2 - direct laser surgery is the use of modern computer controlled precision of the excimer laser to create a new profile of the cornea to further beams focused precisely on the retina. After reprofiling of the corneal surface, the surface of the cornea flap is separated in the first stage is returned to his seat. Sutures are not used, because the flap is well fixed in a few minutes after the operation due to adhesive (adhesive) properties of the basic substance of the cornea - collagen. In this case, the high quality of cut provides a fast and strong agglutination ("adhesion") and the flap is firmly in place. As a result, the surface protective layer of the cornea is almost no damage (as in PRK method), so the patient does not feel after the surgery is almost no discomfort.

There are no stitches, scars, cuts. All of the laser are controlled by computer, which lays the program with data calculated individually for each patient, with the maximum precision determines the amount of laser correction.

Operation is performed under local anesthesia.
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Limitations to laser vision correction
Age 18 years (this is due to the need to complete formation of the eyeball)
Pregnancy and the entire lactation period (before the restoration of hormone levels);
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Contraindications for laser vision correction
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Absolute contraindications
General:
Autoimmune disease (collagen disease, arthritis);
Primary and secondary immunodeficiency states;
Systemic diseases affecting the healing process.
The eye:
One eye;
Corneal thickness less than 450 (440) m;
Glaucoma;
Keratoconus with corneal thinning;
Progressive myopia;
Cataract, regardless of stage of development
Operated retinal detachment;
Herpes simplex and herpes zoster.

In the case of progressive myopia usually first prescribe an operation called scleroplasty to halt the deterioration of vision. Currently, however, this practice is almost never used [citation needed 543 days].
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Relative contraindications
General:
Diabetes;
The presence of a pacemaker in a patient;
Pregnancy and postpartum infant feeding (hormonal changes);
Psychoses.
The eye:
Acute and chronic inflammatory diseases of the anterior and posterior parts of the eye, lacrimal apparatus;
Penetrating scarring of the cornea (in the optical area);
Pronounced changes in the fundus.
Retinal changes, which require prophylactic laser photocoagulation.
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Complications

The conical shape of the cornea in keratoconus.

Subconjunctival hemorrhage - a common benign postoperative complication.

The likelihood that a patient will have unresolved complications after 6 months of operation according to various estimates ranging from 3% [1] to 6%. [2] The risk that a patient will suffer inconvenience adverse visual effects such as halos, diplopia, loss of contrast and glare, depending on the degree of ametropia before the laser surgery and other risk factors. [3] For this reason it is essential to take into account the individual risk of each patient rather than the average probability for all patients. [4] Common complications after LASIK'a There are the following [5] [1]:
Keratoconus (cone-shaped protrusion of the cornea)
Caused by the operation of dry keratoconjunctivitis (dry eye syndrome ")
Overcorrection [6] or lack of correction (gipokorrektsiya)
Fluctuations in visual acuity
Halo [7] around lights at night.
Sensitivity to light
Diplopia [8]
Folds in the corneal flap [9]
Displacement of the processing zone of the cornea
Foreign body / bodies or fluid under the corneal flap
A thin corneal flap, or formed a small hole [10]
Caused by the operation of astigmatism
Corneal ectasia
Destruction of the vitreous
Erosion of the epithelial tissue
Ingrowth of the epithelium of the cornea under the flap - about 1% of cases, most of them do not require surgical intervention [11]
Zadnegialoidnaya detachment [12]
Complications related macular [13]

Complications caused by LASIK'om divided into those that arise during the operation in the early period after surgery and during the late period after the operation: [14]
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Other

Lasik and similar laser surgery (eg, PRK, LASEK and Epi-LASEK) change the biomechanical properties of the cornea. These changes interfere with accurately measure your eye pressure, important in the diagnosis of glaucoma and its treatment. The changes also affect the calculation of intraocular lenses, when you operate on cataracts. Right intraocular pressure and intraocular lens parameters can be calculated if you are able to provide medical information about the state of your eyes before, during and after surgery.

Although LASIK technology have been made several improvements [15] [16] [17], there is evidence of long-term complications [18]. Moreover, it remains a small chance of complications such as turbidity vision, halo or glare, and some of them may be irreversible, because the procedure is that laser surgery is irreversible.

Chance of complications at the yellow spot is from 0.2 [13] to 0,3%. [19] The probability of retinal detachment is estimated at 0.36%. [19] The prevalence of neovascularization horoidalnoy estimated at 0.33%. [19] The prevalence of uveitis is estimated to be 0.18% [20] Additional studies are also required to assess the effect of increasing the risk of intraocular pressure that occurs in the time of the transaction, the preservation of retinal nerve fiber layer [21].

Although the cornea after LASIK is usually thinner, as part of the stroma was removed, the surgeons try to preserve the minimum allowed thickness to avoid the risk keratectasia cornea. Low air pressure at high altitudes above sea level, was not especially dangerous to the eyes of patients who underwent LASIK. However, some climbers have experienced blurred vision at high altitudes. [22] [23] [24] No published reports, reporting on complications after LASIK during scuba diving. [25]

The data on significant reduction in the number of corneal keratocytes (fibroblast-like stromal cells) after LASIK-therapy [26].