What can patients expect from cataract surgery?
ABSTRACTCataract surgery has evolved into an outpatient procedure that requires minimal anesthesia and significantly improves visual function for about 90% of patients. With the help of their primary care physician and ophthalmologist, patients can decide when cataract surgery is appropriate for them. In addition, patients may have a choice about the type of synthetic lens implant that fits their visual needs.
KEY POINTS
- Known risk factors for cataract include age, family history, smoking, sunlight exposure, diabetes, trauma, and corticosteroid use.
- Patients taking aspirin or other anticoagulant drugs do not need to change their regimen before undergoing cataract extraction. However, measures of control such as the international normalized ratio should be within the therapeutic range.
- Any patient who develops pain and decreased vision 2 to 5 days after surgery requires an immediate evaluation by an ophthalmologist.
- Improvements in cataract surgery include topical anesthesia and phacoemulsification—dissolving or emulsifying the lens through a small incision.
- New multifocal intraocular lenses offer refractive correction and give some patients the ability to see both close up and at a distance without glasses after cataract surgery.
Cataract surgery in patients with age-related macular degeneration
Age-related macular degeneration is the most frequent cause of irreversible blindness in the United States for patients older than 65 years.35 Because our population is aging, this condition—and cataract surgery—are likely to become even more common.
Studies have shown that patients with age-related macular degeneration experience significant improvement in vision and quality of life after cataract surgery.
However, some studies suggest that, over the long term, cataract extraction can induce the development of age-related macular degeneration or accelerate its progression.36 This could occur through postoperative inflammatory mechanisms. In addition, photo-oxidative retinal damage is known to play a role in age-related macular degeneration.37–39 Therefore, intraocular lenses that block light within the wavelength range proven to cause phototoxicity (“blue-blocking” lenses) may be beneficial in patients susceptible to age-related macular degeneration (eg, whites, patients with a family history of macular degeneration). A randomized clinical trial is needed to study the ability of blue-blocking lenses to prevent this condition. Well-designed large longitudinal studies of older patients undergoing cataract surgery are also needed to more accurately address the risk of developing age-related macular degeneration after cataract surgery.
Cataract surgery in patients who have undergone refractive surgery
In patients who have previously undergone refractive surgery, selecting the appropriate intraocular lens implant can be challenging, because refractive surgery may change the shape of the cornea so that measurement of its refractive power is less reliable. In these patients, the ophthalmic surgeon performs additional tests and may obtain records of the patient’s corneal power measurements before refractive surgery in order to compare these with the patient’s current refraction.1
INNOVATIONS IN CATARACT SURGERY: MULTIFOCAL LENS IMPLANTS
As people age, their eyes lose the ability to accommodate to view objects at close distances, a condition called presbyopia. For this reason, most older adults need glasses or bifocals for near tasks such as reading.
New multifocal intraocular lenses allow some patients to see clearly both at distance and close up without glasses after cataract surgery. The standard intraocular lens is monofocal, ie, it has a single focal length. Multifocal intraocular lens implants have multiple focal lengths through the use of zones of differing refractive power. So far, three multifocal intraocular lenses have been approved by the US Food and Drug Administration. They provide better near vision than standard monofocal lenses.
However, the improvement in near vision and increased freedom from wearing glasses may come at the price of adverse effects. Some patients with multifocal lenses report reduced contrast sensitivity and more halos around lights compared with patients who receive monofocal implants.40 Patients should be counseled about the benefits and possible risks of multifocal lenses, and the surgeon should take the patient’s preferences into account.
Medicare has approved the requirement of an additional cash payment from patients who undergo implantation of a multifocal lens or the newly available astigmatism-correcting lens. This is intended to offset the increased cost of the lens and the time to evaluate and counsel the patient.
