5
astigmatism. AKs/LRIs can be performed
successfully with both a blade and a fem-
tosecond laser, but the femtosecond laser
provides some theoretical advantages.
Incorporating laser vision
correction to address
residual refractive error
Correcting low refractive errors:
Efficacy and safety
There are a number of options now
available to surgeons for treating residual
refractive error after multifocal IOL implan-
tation. These include lens repositioning,
IOL exchange, piggyback IOL insertion,
astigmatic keratotomy, and laser vision
correction. Dr. Schallhorn focused his
attention on photorefractive keratectomy
(PRK).
According to Dr. Schallhorn, PRK is
indicated when there is a visually signifi-
cant refractive error after multifocal IOL
implantation that does not warrant IOL
repositioning or exchange that the patient
wants corrected or improved. The patient
should also meet all the conditions for
PRK.
At Optical Express, Dr. Schallhorn and
his colleagues have performed post-multi-
focal IOL PRK in 602 patients (724 eyes),
with a mean age of 54 years (range 20 to
87 years). Most cases had undergone re-
fractive lens exchange, though there were
cataract patients in the population as well.
Most of the patients were treated with PRK
six to 12 months after MIOL implantation
(48.9%); many underwent treatment within
the first six months (31.5%), and some as
late as 42 to 48 months after implantation
(0.1%).
From a mean pre-PRK sphere of
+0.14±1.12 D, their patients achieved a
mean post-PRK sphere of +0.08±0.57 D;
cylinder went from 1.08±0.67 D pre-PRK to
0.43±0.46 D post-PRK. Manifest spherical
equivalent went from –0.40±1.05 D
pre-PRK to –0.14±0.57 D post-PRK.
"Basically, performing PRK after a
multifocal IOL results in good refractive
predictability," said Dr. Schallhorn.
The patients also achieved significant
improvement in visual acuity. Whereas
only 8.4% of patients saw 20/20 uncor-
rected distance visual acuity (UDVA)
pre-PRK, 50.8% of patients achieved
20/20 or better post-PRK, with 25.4%
achieving 20/16.
Classic dry eye; one month treatment of topical steroids and cyclosporine
shifted the recommended IOL from an 18.5 D lens to a 20.5 D lens
