A cataract is an eye disease in which the natural lens of the eye turns cloudy or opaque and becomes unable to focus light appropriately on the retina, resulting in blurry vision and other seeing difficulties. Except for congenital cataract and traumatic cataract, cataracts are most commonly caused by aging (age-related cataract). The common way to treat serious cataract is to surgically remove the cloudy natural lens and replace it with an intraocular lens (IOL).
IOLs have been used for several decades. The lens materials include polymethylmethacrylate (PMMA), silicone, and hydrophobic acrylate. IOLs provide the refractive power in place of the natural lens to focus light onto the retina and restore clear vision.
There are several different surgical techniques used in cataract surgery. Phacoemulsification is the most widely used method. It involves the use of an ultrasonic handpiece equipped with a titanium or steel tip. The tip vibrates at ultrasonic frequency to sculpt and emulsify the cataract while the pump aspirates particles through the tip. After cataract extraction procedures, an IOL is placed into the remaining lens capsule. With the short procedure time and the local anesthetic, phacoemulsification cataract surgery can be done on an outpatient basis. The micro incision prompts faster healing and helps to restore clear vision quickly. As with any type of surgery, there are risks associated with cataract surgery and the IOL placement, e.g. corneal endothelial damage, endophthalmitis, and retinal detachment. And the most common postoperative complications are secondary cataract and IOL decentration.
The design of IOLs has been progressed from conventional rigid spherical lens to the latest foldable multifocal aspherical lens, reducing the healing time and improving the visual acuity. There are a wide variety of IOL types. Patients should consult doctors to choose the type of IOLs by considering personal lifestyle and specific visual needs.
Intraocular lenses (IOLs) are medical devices that are required to be assessed and approved by TFDA. The premarket review will include for biocompatibility, sterilization validation, and performance (such as power measurements, light transmission, image quality and so on) to ensure the effectiveness and safety. Only TFDA-approved IOLs are legally allowed to be marketed in Taiwan.
TFDA recommends that you fully discuss with your surgeon about your overall eye health, your occupation, and your daily activities to choose the IOL that suits you the best. Besides, be sure to strictly follow the preoperative and postoperative instructions. If you think you may be experiencing an adverse reaction that may reasonably be regarded as surgery-related or lens-related, check with your eye care professional immediately. If you would like to learn more about your devices, please visit the database at http://www.fda.gov.tw/MLMS/H0001.aspx. If you have device-related problems, please file reports electronically at http://qms.fda.gov.tw, or call the adverse reaction reporting line at 02-2396-0100.