The newest advance in cataract surgery – Femtosecond Laser Surgery and Astigmatism
Cataract surgery has always been on the leading edge of innovation and the latest development is no exception. There are numerous advantages of Femtosecond Laser Cataract Surgery and in this blog I am going to limit the discussion to Astigmatism. The first thing to understand about this procedure is the incredible accuracy achieved. Using suction to hold the eye immobile, a built in imaging system identifies the different structures to the surgeon who then verifies that the software has correctly identified where the incisions are to be made. The laser then makes these incisions with an accuracy that cannot be matched by human hands.
After cataract surgery, astigmatism is due to the shape of the cornea. Astigmatism is any deviation the cornea has from spherical. Almost all corneas have some astigmatism and when you buy glasses, this is one of the factors that are corrected by your prescription lenses. Modern cataract surgery really does not impact the corneal shape, so the pre-existing astigmatism remains the same after surgery. Moderate to severe forms of Astigmatism should be corrected with special toric IOLs (intraocular lenses) that have the astigmatism correction in the lens – this is for another discussion. Mild to moderate forms of astigmatism can be accurately corrected with Femtosecond Laser Surgery.
In traditional cataract surgery, the surgeon uses a diamond scalpel of pre-determined length to make incisions in the peripheral cornea to try and make the cornea more spherical. The problem with this approach is the variability of the corneal thickness at this location and the distance from the center of the eye. Both of these factors will dictate the outcome and leads to somewhat unpredictable results. With Femtosecond Cataract Surgery, the imaging system measures the thickness of the cornea and always places the incisions the same distance from the center of the eye. The system then presents this to the surgeon and allows him to further customize the treatment. Once the surgeon accepts the location and depth of the incisions, he depresses a foot pedal and the laser takes about 3 seconds to make both incisions with the exact depth and length your surgeon has determined would be best for your visual outcome.