Refractive lens exchange (RLE) is a surgical procedure that is performed to mainly correct refractive errors such as short sight, long sight, astigmatism, and presbyopia (age related difficulty in reading at close distance ie newspapers). RLE should therefore reduce or eliminate the need for prescription glasses or contact lenses. The surgical procedure involves removing the clear lens and replacing it with a plastic lens, an intraocular lens (IOL) implant.
There are different types of IOL’s but they can be broadly divided in to monofocal and multifocal IOL. Monofocal IOL have one fixed point of focus and that is usually fixed for distance vision. Therefore you will reduce spectacle dependence for distance vision but will require spectacles for near vision (reading newspapers). Multifocal IOL on the other hand reduce your spectacle dependence for near, intermediate and distant vision.
Various multifocal IOL’s are available in the market, including bifocal and trifocal IOL’s. Most of these IOL’s will also come with the ‘toric’ option to correct astigmatism. Each of them have their own advantages and indications. Monofocal IOL are ideally suited for patients who do not want the associated problems (such as glare/haloes) with multifocal IOL or have an associated eye problem. Spectacles will be needed mainly for near vision if monofocal IOL have been used Monofocal IOL can be used to provide monovision (one eye is dominant for distant vision and the other is dominant for near vision) and this will allow you to see well in the distance and read medium sized print newspapers.
RLE is usually performed in patients over the age of 50 years, high prescription of glasses or in the presence of cataract. Laser vision correction and phakic IOL implants are procedures that may be discussed as alternative to RLE. Each has it’s own indications.
Complications for this procedure are very similar to cataract surgery. However, there are additional problems which can occur due to the multifocal IOL implants. These include visual glare, haloes and other visual symptoms that may interfere with your vision and ability to drive, particularly at night. Most of the patients get used to these symptoms over time. However, in a very small number of cases it may be necessary to remove the multifocal IOL and replace it with a monofocal IOL.
Due to the limitation in calculating the power of IOL implant (Biometry), some patients may require laser refractive surgery to fine tune their vision. There is a higher incidence of retinal detachments in patients who have underlying myopia and undergo RLE. Therefore if you have symptoms such as flashing lights, floaters or a curtain like field defect, you should get in touch with your surgeon or the local eye casualty department.