In
January of 1998, the multifocal intraocular lens (IOL) had recently received FDA
approval and was made available to U.S. eye surgeons for general use. The multifocal
IOL is designed to reduce dependence on eyeglasses following cataract surgery,
and the IOL is gaining acceptance as a potential refractive surgical option for
select patients.
Until FDA approval of the multifocal IOL,
the only available intraocular lenses were monofocal IOLs, which are designed
to provide vision at one distance, typically far. Patients implanted with traditional
monofocal IOLs usually require glasses for near distance tasks such as reading.
With the introduction of the multifocal IOL, cataract surgeons may offer to patients
the potential for a range of uncorrected vision from near to far. This
revolutionary IOL uses multiple concentric rings of varying optical power, thus
extending the range of uncorrected vision. With the multifocal IOL, vision is
more akin to the eyes of a 40 or 50 year old. Clinical studies have shown that
89% of patients implanted with the multifocal IOL are able to read small print
without glasses. Patients are generally less dependent on eyeglasses and, as such,
often enjoy an enhanced quality of life. In clinical studies,
which were required prior to FDA approval of the multifocal IOL, 41% of patients
who received the multifocal IOL never wore glasses, compared to 11% of those patients
implanted with the traditional monofocal IOLs. Additionally, for near tasks, 38.4%
of multifocal patients did not need glasses, compared to 9.8% of the monofocal
group. Finally, those receiving multifocal IOLs were more likely to never wear
glasses for far distance vision than those with monofocal IOLs (84.9% vs. 52.4%,
respectively). Some patients may experience undesirable
visual sensations when implanted with the multifocal IOL. In clinical studies,
15% of patients experienced severe difficulty with halos around lights and 11%
had severe difficulty with glare. In comparison, only 6% of patients implanted
with the monofocal IOL had severe difficulty with halos and only 1% had severe
difficulty with glare. Less than 1% of patients implanted with the multifocal
IOL had such disturbing halos and glare that they requested removal of the implant.
In this case, the traditional monofocal IOL is usually implanted instead. Interestingly,
the great majority of patients implanted with the multifocal IOL reported that
glare and halos did not impair their vision or interfere with their daily activities.
In fact, patients implanted with the multifocal IOL expressed greater satisfaction
with both their daytime vision and night vision than monofocal patients. The
advantages and disadvantages of both IOLs must be carefully considered prior to
surgery. Most EyeMDs believe that the best candidate for the multifocal IOL is
an individual who accepts the possibility of glare and halos at night in exchange
for reduced dependence on glasses. The great majority of patients implanted with
the multifocal IOL appear to enjoy good vision over a range of distances from
near to far, and consider the visual side effects only mildly disturbing. In fact,
the great majority of patients with multifocal IOLs implanted in both eyes welcome
the trade-off for their reduced dependence on eyeglasses.
Cataract Surgery
| 
