Bioptics: Bioptics is a combination procedure involving a PIOL implant followed by LASIK. It is recommended for the most extreme levels of myopia and hyperopia when neither technique alone will entirely correct the refractive error. This combined technique can be used to correct over 30.00 diopters of myopia - twice the maximum amount that can be safely corrected with LASIK.Clear Lens Extraction (CLE): Clear lens extraction (CLE) involves removing the eye's lens, just like in a cataract operation. This is done with a special ultrasound instrument and may be accompanied by eye-drop anesthesia. A flexible synthetic lens implant of the proper power is then placed inside the eye through an extremely small incision to correct the refractive error. The procedure can be completed without sutures. Visual recovery is quite rapid. As with LASIK, most patients are able to return to work the day following their procedure.
CLE is most commonly performed to treat higher levels of farsightedness in patients over age forty. The optical results are superior to LASIK for these higher corrections. CLE may also be used to correct higher levels of nearsightedness and may be fine-tuned with LASIK if a small refractive error remains. Some surgeons have used CLE to treat extremely nearsighted or farsighted patients who are not candidates for LASIK or PRK.
The major drawbacks of CLE are the risk of postoperative retinal detachment (more of a risk with nearsighted than farsighted patients), and the risks of intraocular surgery (including the potential, albeit uncommon, risk of endophthalmitis).
If both eyes are corrected for distance vision, CLE patients will require reading glasses after their procedure. As with LASIK and PRK, however, monovision corrections are possible with CLE to decrease or even eliminate one's need for reading glasses. Or, a new intraocular lens called the ARRAY lens can be implanted at the time of lens extraction. The multi-focal ARRAY lens allows you to see both near and far after the operation. For the best results, both eyes should be implanted with the lens. Because of its multi-focal capacity, some patients experience a loss of contrast at night and also develop halos around lights. If these symptoms become problematic, the ARRAY lens can be removed and replaced with a conventional lens implant.
Laser Thermal Keratoplasty (LTK): For low amounts of farsightedness, a technique called laser thermal keratoplasty (LTK) is a possible method of thermally changing the shape of the cornea. A special holmium laser is used to deliver laser energy to the peripheral cornea to slightly tighten the fibers and thereby steepen its curvature. The technique seems to work only for low amounts of farsightedness.
There are two disadvantages of LTK. First is the long time needed for vision to stabilize. This process can take months, requiring multiple pairs of glasses in the interim. The second disadvantage is that the effect wears off in a substantial percentage of patients. A patient in whom the effect wears off either faces having the treatment repeated every year or so, or turns to LASIK for a permanent correction.
Conductive Keratoplasty (CK): In conductive keratoplasty (CK), a special probe introduces an electrical current to the peripheral cornea, shrinking the corneal fibers. Similar to LTK, this acts like tightening a belt, causing the central cornea to steepen. It is effective for small amounts of hyperopia. The procedure takes less than five minutes and is essentially painless. It may be performed in a doctor's office without the need of a laser suite. The major advantage of CK is its relative safety. Because all the work is done on the peripheral cornea, the risk of central corneal scarring (through the visual axis, or line of sight) is minimal. The visual recovery with CK is fairly quick, although generally somewhat slower than with LASIK. CK is considered by many surgeons to be the next advance over LTK because its effect appears to be permanent.
Surgery for Presbyopia: One of the more exciting areas of ophthalmology is the surgical treatment of presbyopia - the stiffening of the natural lens that decreases near vision as we age. Several devices and surgeries have been tried, all of which attempt to enlarge the circumference of the eye and tighten the fibers that control the focus of the lens. These fibers are thought to stretch and become less effective as we age.
Anterior Ciliary Sclerotomy (ACS): Anterior ciliary sclerotomy (ACS) is a surgical procedure for relieving presbyopia. Several small incisions are made in the sclera (coating of the eye) directly over the muscle that controls the lens. This procedure expands the circumference of the eye. ACS may be combined with the placement of small silicone plugs into the scleral grooves. These plugs may help the effect last longer.
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