Laser-Assisted In Situ Keratomileusis, commonly known as LASIK, is a surgical procedure that reshapes the cornea to correct refractive errors and improve vision. This procedure has helped millions of people reduce or eliminate their reliance on glasses and contact lenses. While traditional LASIK uses a standard prescription to guide the laser, Custom LASIK represents an advanced, highly personalized form of this vision correction surgery. It leverages sophisticated technology to create a treatment profile unique to the individual eye, aiming for a higher quality of vision beyond simply achieving 20/20 acuity.
Defining the Custom Difference
Conventional LASIK is designed to correct common visual impairments known as lower-order aberrations, which include nearsightedness, farsightedness, and regular astigmatism. These conditions are the standard errors corrected by glasses or contact lenses, and conventional LASIK uses a treatment profile based on these basic prescription measurements. While effective, this approach can sometimes leave behind subtle visual imperfections that affect overall clarity.
Custom LASIK, by comparison, addresses both these lower-order aberrations and the more complex higher-order aberrations. These higher-order errors are minute distortions in the eye’s optical system that cannot be corrected with a standard lens prescription. They are responsible for issues like night glare, halos around lights, starbursts, and decreased contrast sensitivity.
The distinction lies in the level of detail used for the correction plan. Custom LASIK creates a unique, highly detailed “fingerprint” of the patient’s eye that is approximately 25 times more precise than the measurements used in traditional methods. By addressing these individual imperfections, Custom LASIK aims to maximize the quality and crispness of the resulting vision, offering a greater chance of avoiding post-operative visual disturbances, particularly in low-light conditions.
The Technology Behind Customization
Achieving this high level of customization requires advanced diagnostic imaging technology, primarily the use of a wavefront aberrometer. This sophisticated device measures how light travels through the entire optical system of the eye, capturing the unique way light rays are distorted on their path to the retina. The process involves projecting a beam of light into the eye and then measuring the light that reflects back.
The wavefront aberrometer uses this reflected light data to create a three-dimensional map of the eye’s surface and internal optics. This map details all the irregularities, including the minute higher-order aberrations that are missed during a standard eye exam. The resulting data is then fed directly to the excimer laser, which will be used for the surgical correction.
In some cases, corneal topography is used in conjunction with wavefront technology, particularly for eyes with pre-existing irregularities on the corneal surface. Corneal topography specifically maps the curvature of the cornea. Whether guided by wavefront mapping, topography mapping, or a combination of both, this digital blueprint ensures the excimer laser treatment is precisely tailored to the individual eye’s optical needs.
The Custom LASIK Procedure
The Custom LASIK procedure begins with the collection of detailed patient data, which is the high-resolution mapping of the eye performed with the wavefront or topography technology. This mapping phase is performed before the patient enters the operating suite, ensuring the treatment plan is finalized and ready to direct the laser during the reshaping of the cornea.
Once the patient is prepared in the operating room, the actual surgical correction begins with the creation of a thin, hinged flap on the outer layer of the cornea. In modern Custom LASIK, this flap is typically created using a femtosecond laser, making the procedure entirely bladeless. The femtosecond laser delivers rapid, tiny pulses of light to separate the corneal tissue at a predetermined depth, which allows the surgeon to gently lift the flap to access the underlying tissue.
With the corneal flap temporarily folded back, the excimer laser is positioned over the eye to begin the reshaping process. The laser applies the customized treatment profile derived from the earlier wavefront or topography map, precisely removing microscopic amounts of tissue to correct both lower and higher-order aberrations. This process is very fast, often taking only a few seconds to complete the ablation.
After the laser treatment is finished, the surgeon carefully repositions the corneal flap back into its original place, where it adheres naturally without the need for sutures. The total time for the procedure is typically less than 15 minutes for both eyes, and the patient is advised to rest immediately after leaving the operating room.