LASIK for Nearsightedness
Nearsightedness or Myopia occurs when the eye is long in the front to back direction.
This occurs from birth and typically progresses into the late teens and early twenties. Nearsightedness is characterized by blurry distance vision and excellent near vision without glasses. Nearsightedness is classically treated with glasses or contact lenses.
LASIK is an outstanding option for nearsightedness, particularly for cases of mild and moderate myopia in patients in their 20’s, 30’s and 40’s, providing outstanding vision at all distances without glasses or contact lenses. Higher levels of myopia (e.g. above -9 to -10 diopters) is typically better treated with the EVO Visian ICL procedure. The higher the amount of nearsightedness, the more tissue has to be removed from the cornea during LASIK to flatten its curvature. In situations where a large amount of myopia needs to be corrected, there may not be adequate corneal tissue available to safely perform the correction. Dr. Hamilton will obtain detailed maps of your corneas (corneal topography) during the consultation. These maps provide information on corneal shape and thickness. After reviewing these maps and other tests, Dr. Hamilton will discuss your goals and let you know which procedure is best for your particular situation.
LASIK for Farsightedness
Farsightedness or Hyperopia occurs when the eye is short in the front to back direction. This occurs from birth and is typically characterized by eye strain when observing near objects (e.g. cell phone, reading, putting on make up, computer). The age at which these symptoms appear depends on the amount of farsightedness. Extreme hyperopia can manifest during infancy and early childhood: characterized by eyes that cross. Very mild hyperopia may not manifest itself until the early forties when near vision becomes a strain, particularly in dim light. Most farsighted patients have excellent distance and near vision for the first 3 decades of life. Struggling with near tasks then brings them into the eye doctor where traditionally reading glasses are prescribed.
LASIK is an outstanding option for farsightedness, particularly in cases of moderate and higher hyperopia. Patients who experience eye strain with near work in their 20’s and 30’s benefit significantly from hyperopic LASIK. You can think of the procedure as taking the burden off the natural lens inside the eye which is struggling to focus up close. Patients often report headaches and eye strain after computer work. By reshaping the cornea and making it steeper with LASIK, now the lens inside the eye doesn’t need to strain. It can work much easier over a wider range, to focus on near tasks, lessening eye strain and providing significant relief to the farsighted patient. The natural loss of focusing power of the lens, called presbyopia, will still occur and reading glasses will still be needed in the future. But hyperopic LASIK can be a wonderful solution to relieve eye strain for patients in their 20’s, 30’s and early 40’s. After the mid 40’s, a Refractive Lens Exchange procedure (RLE) may be the better option to correct both near and far vision. Dr. Hamilton will use his expertise during your consultation to make the perfect recommendation for your particular situation.
LASIK for Astigmatism
Astigmatism typically occurs when the cornea (front window of the eye) has an oval or football shape rather than a round or basketball shape. The best optics of the eye occur when light passing through the cornea is focused to a single point on the retina (camera film in back of the eye). Light entering through a round cornea comes to a single point of focus while light entering through an oval cornea comes to a blurred, elongated focus. This elongated focus is perceived as distortion, ghosting and blurred vision at all distances. Astigmatism occurs with either nearsightedness or farsightedness.
LASIK is an outstanding option for astigmatism treatment. The laser is used to reshape the oval shaped cornea into a round shape, improving clarity of vision. Patients with mild and moderate nearsightedness or farsightedness with astigmatism are typically candidates for LASIK. Higher levels of myopia with astigmatism may be better treated with the EVO Visian ICL procedure. After reviewing all of the diagnostic testing at your consultation, Dr. Hamilton will discuss your goals and let you know which procedure is best for your particular situation.
With Rex Hamilton, MD, you will find state of the art technology throughout all aspects of the LASIK experience. Let us walk you through the entire process below, and give you a sense of the most comprehensive LASIK experience available in Los Angeles!
This experience consists of:
- Refractive Surgery Patient Screening
- LASIK Surgical Planning
- LASIK Flap Creation
- Corneal Reshaping
Refractive Surgery Patient Screening
LASIK surgery with Rex Hamilton, MD, has enjoyed enormous success for more than a decade now due not only to the cutting edge laser technology used during surgery, but also because of the comprehensive screening process utilizing the very latest diagnostic technology to determine your candidacy for LASIK.
GALILEI® G4 (Zeimer)
Rex Hamilton, MD, uses the GALILEI G4 corneal mapping system during the refractive surgery screening process. This amazing tool acquires a detailed, topographical map of the front and back surface of the cornea, the window on the front of the eye. Dr. Hamilton has been using this type of mapping for more than 15 years and has published extensively on the benefits of this advanced technology. It is critical to accurately map both the front and back corneal surfaces to determine the overall health of the cornea. Much like a topographic map identifies areas of elevation for a hiker, the GALILEI system provides a detailed map of elevations and depressions, steep and flat areas, for the both front and back corneal surfaces. In addition, the system measures the corneal thickness across the entire cornea. This information is vital in identifying whether or not the patient’s cornea has enough tissue to safely treat their nearsightedness, farsightedness and astigmatism. A disorder known as keratoconus can exist without a patient being aware they have it. This disorder is characterized by a cornea that is biomechanically weaker than normal. Performing refractive surgery in such a cornea can lead to a worsening of the overall corneal shape, leading to decreased vision. While using the GALILEI G4 to screen patients does not guarantee keratoconus detection, the system has the most advanced algorithms available to detect this abnormality.
Appearance of normal cornea on Galilei maps. Upper right map is of the back surface of the cornea.
Appearance of abnormal cornea on Galilei. Compare the upper right map with that of the normal cornea above. The red “hot spot” identifies an area of protrusion, indicating the cornea is weak and should not undergo LASIK.
Dr. Hamilton has published a number of studies, including several using the GALILEI system, to help develop these algorithms for early keratoconus detection (see references below).
*B Sonmez, MP Doan, DR Hamilton. Identification of Scanning Slit-Beam Topographic Parameters Important in Distinguishing Normal from Keratoconic Corneal Morphologic Features. American Journal of Ophthalmology 2007; 143(3), 401-8.
*ME Sy, A Ramirez-Miranda, S Zarei-Ghanavati, J Engle, J Danesh, DR Hamilton. Comparison of posterior corneal imaging before and after LASIK using dual rotating scheimpflug and scanning slit-beam corneal tomography systems. Journal of Refractive Surgery 2013; 29(2), 96-101.
LASIK Surgical Planning
Once all your measurements are completed, Dr. Hamilton and his colleagues use a sophisticated software program that analyzes your unique characteristics (e.g. age, gender, amount of correction, environmental conditions, etc.) to determine the optimum laser setting for each of your eyes. Dr. Hamilton and his colleagues presented a paper at the American Society of Cataract and Refractive Surgery meeting describing an advanced nomogram he developed to optimize patient outcomes*. A nomogram is an equation derived using previous patient information to provide the best laser settings for optimized future patient outcomes.
* JB Biebesheimer, DR Hamilton. Development of an advanced nomogram for LASIK surgery (paper). American Society of Cataract and Refractive Surgery Annual Meeting, San Francisco. April 2009.
LASIK Flap Creation
Dr. Hamilton uses the highest quality Laser Visumax-Zeiss!
“The VisuMax® Femtosecond Laser Its remarkable features are its precision and innovative detail. With the VisuMax®, Zeiss is significantly shaping the world of refractive surgery. This groundbreaking laser system employs high-performance femtosecond laser technology and is characterized by its outstanding cutting precision, highly efficient speed and gentle treatment technique”.
The accuracy and predictability of the VisuMax® laser have allowed some patients who were previously ineligible for LASIK to now have the procedure. With the FS laser, unlike with mechanical instruments, your surgeon is able to precisely program the dimensions of your flap (diameter and thickness) based on what’s best for your eye. Dr. Hamilton and his colleagues published a scientific study suggesting the use of a femtosecond laser to create the LASIK flap has a more consistent and predictable effect on corneal biomechanics (i.e. strength) than the use of a microkeratome (blade) system.
The final step in the LASIK experience is the reshaping of the cornea. An excimer laser is used to precisely remove microscopic amounts of corneal tissue to change the curvature of the cornea. The ideal excimer laser is fast, precisely controlled with advanced eye tracking and comfortable for the patient.
The Eye-Q excimer laser is the fastest laser available in the industry. At 400 Hz, it is 8 times faster than its predecessor. Faster treatment times translate to more consistent and predictable patient outcomes as well as an easier, more comfortable patient experience. With speed comes the responsibility to track the eye precisely to ensure every pulse is placed in the exact, intended location. The Eye-Q eye tracking system is the most robust currently available, reliably locking on to the pupil regardless of eye color or lighting conditions.
Contact one of our staff today to set up your complimentary LASIK evaluation!