Challenges of Previous Eye Surgeries
Many of our patients have already undergone previous surgery for cataracts, refractive surgeries (LASIK, PRK, RK, ICL), retinal laser or surgery, and others. Some of these previous may may affect the quality of the laser energy and the efficiency of treatment but generally these will not increase the risks of treatment. By decreasing the 'efficiency' of the treatment, it may ultimately require more treatment sessions to compensate.
Corneal Refractive Procedures: LASIK, PRK, RK
Corneal refractive surgery re-shapes the front surface of the cornea. The affected optical zone of the cornea may be around 5 to 6 mm in diameter. This leaves a surrounding “transitional” zone surrounded by untouched cornea curvature. Having different zones of curvature may diminish the amount of energy delivered by the YAG laser in treating eye floaters. Generally this will not increase the risk of the procedure, but it may decrease the efficiency of treatment. This can usually be compensated for by greater efforts to move the floaters into a treatable “sweet spot”, using more shots of the laser, or changing the energy settings.
A common age-related change is the gradual darkening, yellowing or browning, or outright opacification of the natural lens of the eye. They can range from mildly irregular optics to complete blinding of an eye. When treating eye floaters, the laser energy must pass through the lens. In moderate-to-advanced cataracts, the irregularity of the optics of the lens may diminish the quality and quantity of the laser energy, making it more difficult to treat. With early or mild cataracts, it is not much of an issue. In more advanced cataracts where your doctor is starting to discuss cataract surgery for you, it may be better to wait until after the cataract surgery to have your floaters treated.
Cataract Surgery with Lens Implant
Cataract surgery removes the clouded natural lens of the eye and replaces it with an artificial lens. The diameter of these lenses is about 5.5mm which is less than a natural lens. If the patient has also had a capsulotomy, the working aperture can be even smaller (3.0x4.0 mm shown here). These much smaller apertures may reduce the opening to as little as 25% as compared to a large pupil with a clear natural lens. Again, this does not increase the risk of procedure, but can significantly reduce the surgeon's view and diminish the laser energy and limit where the laser can be used (that is, more difficulty getting out to the periphery or working in the back 1/2 of the vitreous fluid.
RK is an older corneal refractive surgery procedure where the surgeon placed deep, radially-oriented incisions in the cornea in an effort to flatten the front curvature of it. This changed the optics of the eye, and generally could correct mild-to-moderate degrees of myopia. There are many problems with this procedure, and there are wide varieties of the number of incisions that were placed in the usually range from 4-16 incisions. This creates an irregularity of the cornea that diminishes the quality and amount of YAG laser energy that can be delivered to the floaters. This can usually be compensated for by the surgeon’s experience a technique. Some of the floaters located posterior or peripheral may be difficult to treat effectively through these corneas.
Retina Problems: Holes, Tears, Detachments Repaired
Many of Dr. Johnson’s patients have had had previous retinal hole, tears, and even retinal detachments. They have had their retinal pathology repaired, or lasered as shown here. As long as their retina condition is considered healed and stable, there should be no problem with using the YAG laser in treating vitreous eye floaters.
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