Advanced Vision Analysis & Treatment Technology

Advanced Vision Analysis & Treatment Technology helps to insure great outcomes.

 

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Every refractive surgery patient undergoes an in-depth analysis of their visual system including a thorough ocular and medical history, a comprehensive ophthalmologic examination, and precise measurements of the unique characteristics of your eyes using sophisticated computerized instrumentation. This information is analyzed and then converted via millions of calculations into a treatment algorithm designed especially for your eyes. Our excimer laser system is computer controlled with many quality and safety systems to help insure a great outcome. Our technology includes:

 

Computerized corneal topography–uses thousands of data points from the corneal surface of the eye to produce detailed maps of corneal curvature and power.  Then using mathematical analysis, the data are analyzed to rule out problems in the cornea that could result in poor outcomes for the patient. This allows us to avoid surgery in conditions such as keratoconus, pellucid marginal degeneration and other corneal disease states that would otherwise go undetected.

 

Automated keratometry and refractometry–measures the current refractive state of the eye and cornea avoiding human error in the measurement system. These analyses helps to adjust the astigmatic portion of the surgery and by doing these measurements in the dilated state, to avoid over-correction of nearsightedness and under-correction of farsightedness.

 

Optical Coherence Tomography –Utilizes a so called spectral domain laser imaging system to produce exquisite images of the retina, optic nerve, cornea and the anterior chamber angle. These images are used to insure that there are no undetected problems that could affect the surgical outcome. For instance, we use the corneal pachymetry map and cross sectional image to make sure the cornea has enough tissue for NuSite™ Advanced Surface Ablation and the macular scan to screen for previously undetectable problems in the retina that could negatively affect the outcome.

 

Wavescan™ wavefront aberrometry–This instrument revolutionized  the accurate measurement of each persons unique visual system. This technology was first developed by astronomical physicists to allow our most powerful space telescopes to adjust to aberrations in the Earth’s atmosphere, so that they could see smaller and smaller objects in the universe.  In basic terms, several bright spots are placed on the retina (back inside lining of the eye) by a safe laser light source.  Then, an array of small lenses (“lenslets”) measure the deviation of rays of light from each of these bright spots, and compare them with a perfect wavefront,  as they depart the eye.  This data is converted into maps which depict the so called “normal” or “lower order” refractive errors, such as nearsightedness, farsightedness and astigmatism, but also measure more subtle or “higher order” aberrations which, before this instrument, we could not measure.  These higher order aberrations, such as “spherical aberration”, “coma” and “trefoil”, are very important to minimize in the refractive surgery procedure, as they can negatively affect the quality of the visual outcome especially under low light conditions.

 

CustomVue™ Surgical Planning System–Only Visx CustomVue™ uses sophisticated Fourier (for’-ee-ay) analysis to calculate the proper size, placement and order of placement of the laser applications to achieve the desired correction.  This precise mathematical method uses a series of sine waves of different size and shape to describe the complex pattern of laser applications necessary to correct the “wavefront aberration” found on the Wavescan™ analysis of your visual system.  This method is more accurate than the older types of analysis (which relied on Zernike polynomials), in that it can more exactly describe a complex three dimensional shape such as the Wavefront solution for your corneal treatment!

 

Visx™ S4 IR Excimer Laser System–has many proprietary features that enhance safety and accuracy of the laser treatment, the combination of which is only found on this system:

  1. Variable spot scanning: Utilizes variable size laser pulses from 6.5 mm down to 0.65 mm, which not only speeds up the treatment process but improves accuracy.  The larger spots allow more tissue to be removed per pulse to speed tissue removal, and then the laser shifts to a smaller spot size to refine the smaller details of the desired shape of the wavefront ablation.  This is an industry exclusive. Visx™ has both the smallest spot size and the only variable spot system.
  2. Variable Repetition Rate: Increases or decreases the rate of  application of the laser spots depending on the size of the spot delivered.  This allows the cornea to cool between pulses, keeping the cornea at the proper temperature to optimize outcomes. Visx™ is the only available system with this feature.
  3. ActiveTrak 3D Active Eye Tracking System: The first FDA approved eye tracking system to insure accurate placement of  the desired laser treatment to the exact position on the cornea.  This process is called “registration”, meaning matching up the computer’s calculated placement of laser pulses to the exact position on the eye.  This system has two parts.  The first utilizes an infrared (non-visible) light source and infrared video processing to measure the position of the eye in three dimensions, (think of length, width and depth). The laser then “locks on” to this position for eye treatment. Once treatment commences the laser has the ability to both “actively” and “passively” track.  “Active” tracking means the laser will continue to treat if the eye moves less than one millimeter, with the laser pulses automatically moving to match the associated eye movement.  “Passive” tracking means the laser will pause treatment if the eye moves more than one millimeter.  This occurs automatically and responds faster than the surgeon could react to this movement.  This is very important as some laser systems do not have passive tracking, and will continue treatment even when the eye has moved more than one millimeter.  This causes the laser spots to fall obliquely rather than perpendicularly on the cornea, resulting in a decrease in tissue removal which ultimately affects the outcome.The second part of registration is matching the treatment rotationally.  Each eye is capable of rotation around it’s visual axis.  Two of the six eye muscles on each eye are primarily responsible for this rotation, the superior and inferior oblique muscles, which insert obliquely onto the eye surface.  If one thinks of the the iris like a clock face, one muscle rotates the 12 o’clock position inward towards the nose, and the other rotates the 12 o’clock position towards the ear. The Visx™ system utilizes an elegant system called iris registration (IR) to solve the problem of eye rotation.  When the eye is measured with the Wavescan™ device, an infrared image of the iris is recorded along with the wavefront maps.  The software then selects several prominent “features” of the iris  such as pigment spots, crypts, and blood vessels which it can use to match up or “register” to the iris beneath the laser during treatment.  Most patients have at least some eye rotation going from the upright to the horizontal position. During treatment, the laser detects these features of the iris and rotates the wavefront treatment calculation to exactly match the amount of rotation that has  occurred with the patients lying beneath the laser. Just a small amount of rotation (“torsional”) misalignment can significantly affect the outcome of the procedure, so this feature has been a major improvement in treatment. This same type iris scan software is also used for security access since no two irises are ever the same.

 

Epi-K™ epikeratome system by Moria–We use the Epi-K™ system to remove the epithelium (top layer of cells) prior to the laser portion of the NuSite™ Advanced Surface Ablation procedure.  This technique has several advantages for the patient compared with earlier techniques for surface ablation.  This “epi-LASIK” technique for epithelial removal results in an extremely smooth, pristine appearing corneal surface for applying the laser.  It also produces a very smooth, regular, well defined, perfectly circular edge of epithelium, at least 8mm in diameter.  The cells at the edge are basically untouched, healthy and ready to rapidly populate the laser ablated area, giving this technique the most rapid healing of any surface procedure.  This means better comfort for the patient and quicker visual recovery.  Older techniques used either alcohol or a stiff rotating brush to remove the cells which damaged the remaining cells, slowing recovery and increasing post-operative discomfort. The excimer laser can also be used to remove the epithelium, and does give a smooth surface, but is unable to remove more than a 6.5 mm area of epithelium.  The CustomVue™ treatment requires at least an 8mm optic zone, so patients who undergo laser epithelial removal don’t get the benefit of the full “blend zone” of the treatment (between 6-8mm) which could result in more night vision complaints.  Learn more about epi- LASIK advanced surface ablation procedures and why they are our first choice for laser vision correction at Moria-Surgical.com.

 

Intra-operative and post-operative specialized therapy–We use several different intra-operative and post-operative therapies designed to minimize discomfort, speed recovery and lower risk.  During surgery we use special pharmacotherapy to reduce or eliminate the risk of post-operative haze formation, and a rapid cooling technique immediately following the laser application to markedly improve post-operative comfort.  At the end of the procedure, we place a very oxygen permeable and “wettable” extended wear therapeutic contact lens that has virtually eliminated any significant post-operative pain, with most patients only experiencing mild irritation for 1-2 days.
Post-operatively we use a proprietary combination of both topical (eye drop) and oral (pill) anti-inflammatory, antibiotics, analgesics and anti-oxidants which all help to insure an easy post-operative experience, with fast healing, good comfort and rapid visual recovery.