Premium Intraocular Implants
All patients that are to have cataract or refractive lens exchange surgery need to be aware of their implant choices. Dr. Raymond Stein provides all his Toronto patients with detailed information on all the available options. He will tell them if they are, or are not, a candidate for a specific type of lens. The worse scenario is a patient that has surgery with a standard implant and only later discovers from a friend that they could have had a premium lens (multifocal, toric, or aspheric implant). Not all patients will choose a premium lens but it is important that they are aware of their options.
There have been significant advances in multifocal or accommodative implant technology over the past year. The most impressive implant has been the Restor +3 add from Alcon. This implant has consistently provided distance, intermediate, and near vision. In 2004 Dr. Raymond Stein was the first surgeon in Canada to implant the Restor +4 add. This implant provided distance and near vision but intermediate vision was difficult for the majority of patients. The new Restor +3 add represents breakthrough technology. Some patients may have some glare at night but this is typically mild and in a high percentage of cases diminishes over 6 months. For patients that desire a reduced dependency on glasses the Restor +3 add is Dr. Stein’s implant of choice. If patients are not satisfied with their refractive outcome then a refinement can be accomplished with laser vision correction.
Clinical results of the Toric implant from both Alcon and Rayner have been superior over limbal relaxing incisions for astigmatism. For patients with 1 D or greater of preoperative astigmatism the Toric implant is the lens of choice. This implant can be custom ordered to correct up to 6 D of cylinder. The lens is orientated in the eye along the steep meridian. These implants are made of an acrylic material that adheres to the posterior capsule and prevents rotation. Although limbal relaxing incisions are an alternative method for dealing with preoperative astigmatism the results are highly variable as the effectiveness of the incisions are dependent on the biomechanical properties of the cornea.
For patients that are either not candidates or are not interested in a multifocal or toric implant an aspheric implant is an excellent choice. The cornea normally induces positive spherical aberration and the crystalline lens, at least when we are young, balances this by producing negative spherical aberration. As we get older the crystalline lens changes with the net result that patients have positive spherical aberration. This leads to diminished quality of vision especially at night. An aspheric implant will counter the positive spherical aberration of the cornea, which usually results in superior quality of vision.