Download Optimizing Outcomes With Presbyopia- Correcting IOLs

CATARACT SURGERY
Optimizing Outcomes
With PresbyopiaCorrecting IOLs
Tips to help you achieve 20/20 postoperative visual acuity for more of your patients.
BY RICHARD S. DAVIDSON, MD
T
he availability of presbyopiacorrecting IOLs translates as more
options for vision correction than
ever before. Although not perfect,
these lenses provide patients with visual
freedom that they could not achieve with
traditional monofocal IOLs. Presbyopiacorrecting IOLs may be divided into two
general categories, multifocal and accommodating. To maximize patients’ postoperative satisfaction with these lenses, consider
the potential barriers to optimal vision and
take the necessary steps to correct or avoid
them prior to and during cataract surgery.
PERFORM A COMPLETE
OPHTHALMIC EXAMINATION
A thorough medical history and a comFigure 1. Significant meibomian gland dysfunction/blepharitis. Note the
plete ophthalmic examination are essential
inspissated meibomian glands, telangiectatic vessels on the eyelid margin,
to determining a patient’s candidacy for a
and crusting of the eyelashes.
presbyopia-correcting IOL. After all, it is
unethical and inconsiderate to charge someone for a presbyopia-correcting IOL if a preexisting ocular
I avoid multifocal IOLs when patients have significant
condition would preclude him or her from obtaining the
macular pathology. If the extent of macular pathology is
best possible visual acuity postoperatively.
unclear, optical coherence tomography and/or a referral
In my opinion, patients with a history of recurrent optic
to a retinal specialist can be helpful. I also do not use
neuritis or optic nerve pathology are not the best candimultifocal IOLs in patients with significant cornea guttadates for a multifocal IOL. A single episode of optic neuritis
ta or Fuchs endothelial dystrophy. The cornea guttata
may not be an absolute contraindication, but I would recand/or any mild corneal edema will scatter light in such a
ommend visual field testing to make sure the patient has
way that, combined with a multifocal IOL, will result in
not suffered significant visual field loss. Any patient with sig- suboptimal vision for the patient.
nificant visual field loss from glaucoma is therefore not a
I generally do not recommend multifocal IOLs for
good candidate for a multifocal IOL. This individual might
patients who have undergone previous corneal refractive
benefit from an accommodating IOL, but it would be prusurgery, especially RK, due to an increased loss of condent to consider his or her best visual potential before sugtrast sensitivity and, ultimately, suboptimal vision. An
gesting that he or she pay extra for an IOL that may not
accommodating IOL may be an option for some of these
provide better visual acuity than a standard monofocal lens. patients. They should be advised preoperatively, however,
SEPTEMBER 2011 ADVANCED OCULAR CARE 23
CATARACT SURGERY
“Astigmatic management is a key
step in optimizing postoperative
visual outcomes and patients’
satisfaction.”
that they might not achieve the same benefits as someone who has not undergone corneal refractive surgery.
Finally, presbyopia-correcting IOLs should probably be
avoided in hypercritical patients and those with unrealistic expectations.
OPTIMIZE THE OCULAR SURFACE
A healthy ocular surface contributes to the success
of cataract surgery, and it is especially important when
the patient will receive a presbyopia-correcting IOL.
During the preoperative visit, assess the patient’s ocular
surface and eyelid margins. Treating dry eye syndrome
and blepharitis preoperatively will not only contribute
to a better visual outcome, it will also reduce the risk of
endophthalmitis (Figure 1).1
TREAT CORNEAL ASTIGMATISM
Astigmatic management is a key step in optimizing
postoperative visual outcomes and patients’ satisfaction.
In my practice, any patient with more than 0.75 D of
corneal cylinder receives astigmatic correction at the
time of cataract surgery. In most cases, I perform limbal
relaxing incisions (LRIs). Other options include PRK and,
in some instances, LASIK. I prefer LRIs to excimer laser
correction, because an LRI does not negatively affect
contrast sensitivity, as PRK or LASIK may. This is an especially important consideration for patients receiving multifocal IOLs, which will slightly decrease contrast sensitivity in most patients.2
To ensure the proper treatment of patients’ astigmatism, I obtain the following tests during their preoperative visit: manifest refraction, keratometry (manual,
IOLMaster [Carl Zeiss Meditec, Inc., Dublin, CA], or
another device), and topography. I also measure corneal
pachymetry in order to ensure that the patient has sufficient corneal tissue prior to surgery.
Be sure that the amount and axis of astigmatism correlate between these tests. Never rely on the manifest
refraction alone to plan for astigmatic correction during
surgery, because it does not allow you to accurately differentiate between corneal and lenticular astigmatism. If
the axis of astigmatism shown by the manifest refraction,
keratometry readings, and topography does not match,
reexamine the eye for ocular surface disease and other
24 ADVANCED OCULAR CARE SEPTEMBER 2011
conditions that could be affecting the results.
After quantifying the patient’s corneal astigmatism and
defining its axis, proceed with surgical planning. Both the
Donnenfeld and Nichamin nomograms are very helpful
in this regard (the pros and cons of each nomogram are
beyond the scope of this article). I myself use the LRI
Calculator (www.lricalculator.com). This Web-based
application sponsored by Abbott Medical Optics Inc.
(Santa Ana, CA) allows me to accurately plan my LRIs in
a fashion similar to that of the AcrySof Toric Calculator
(Alcon Laboratories, Inc., Fort Worth, TX), which many
surgeons use for toric IOL calculations.
In some cases, an LRI may increase corneal dryness. I
therefore encourage all of my patients receiving this form
of astigmatic correction to use artificial tear supplements
for the first several weeks postoperatively. When performing an LRI, it is important to remember that no arc
length should exceed 90º, as this puts the patient at significant risk for an overcorrection and may “flip” his or
her axis of astigmatism.
CONSIDER BILATERAL IMPLANTATION
I find that patients are much happier with the bilateral
versus unilateral implantation of presbyopia-correcting
IOLs. I do, however, have some monocular patients with
multifocal IOLs (as well as some patients with a monofocal
IOL in one eye and a multifocal IOL in the other eye), but
I do not believe they are ideal candidates for these lenses.
I do not think placing a presbyopia-correcting IOL in
a monocular patient or a patient with a monocular lens
in his or her contralateral eye is absolutely contraindicated. He or she should be advised preoperatively, however, that he or she may not obtain the same benefits as
would a patient undergoing binocular implantation.
CONCLUSION
Presbyopia-correcting IOLs provide exciting new ways
to give patients more visual freedom. With proper preoperative planning and counseling, implanting these lenses
can fill your practice with happy patients. ■
Richard S. Davidson, MD, is an associate professor of cataract, cornea, and refractive surgery
at the University of Colorado School of Medicine
in Aurora, Colorado. He acknowledged no
financial interest in the products or companies
mentioned herein. Dr. Davidson may be reached at (720)
848-2500; [email protected].
1. Speaker MG,Milch FA,Shah MK,et al.Role of external bacterial flora in the pathogenesis of acute postoperative
endophthalmitis.Ophthalmology.1991;98(5):639-649.
2. Alio JL,Pinero DP,Plaza-Puche AB,et al.Visual and optical performance with two different diffractive intraocular
lenses compared to a monofocal lens.J Refract Surg.2011;3:1-12.