Providing OptimalOptics For Your Astigmatic Cataract Patients

By David Geffen, O.D., F.A.A.O.

Goal Statement:

Premium IOLS present an excellent opportunity for optometrists and their patients, specifically with toric IOLs which can limit large amounts of astigmatism. This articles focues on toric lens technology, patient benefits and selection process and post op-experience.

Faculty/Editorial Board:

David Geffen, O.D., F.A.A.O.

Credit Statement:

This course is qualified for 2 hours of CE Credit. COPE ID: 26815- PO. Check with your local state licensing board to see if this counts toward your CE requirement for relicensure.

Joint-Sponsorship Statement:

This continuing education course is joint sponsored by the University of Alabama School of Optometry. This course is supported by an unrestricted grant from Alcon.

Disclosure Statement:

Dr. Geffen is on the speakers’ bureau for Alcon.

Cataract surgery has advanced faster in the past three years than it has in the previous 20. Today, we are seeing a revolution in how we treat and educate our older patients when it comes to their options for visual correction. Aspheric, accommodative, multifocal and now toric intraocular lenses have truly made cataract surgery a refractive procedure. When discussing visual options with any patient over 50 years of age, one needs to speak about the changes the individual will experience over the next 20 years. The ability to correct nearsightedness, farsightedness, astigmatism and now presbyopia needs to be explained in detail. The focus of this article will address the impact the new toric IOLs make on our practice and for our patients.

Compelling Statistics

The market numbers are staggering! In 2006, the amount of “Baby Boomers” grew to 80 million. And, by 2020, it is estimated that close to 55 million people in the U.S. will be over the age of 65. Adding to these statistics, more than 10,000 people are turning 50 every day.

Of course, this older population translates to more patients who will need cataract surgery. Just consider some of these statistics that illustrate the impact this condition can have if it goes untreated: Worldwide, cataracts are one of the leading causes of blindness, affecting over 18 million people. Additionally, 62 million have low vision as a result of cataracts. This is quite sad in that it is often preventable and even restorable with advances in cataract surgery. Today, cataract surgery is more advanced and offers even more options for our patients than ever before—and more opportunities for our practice. Just consider, “Baby Boomers” are the group who are willing to spend more of their income on themselves. They want to look younger, feel better and have fun. These are the patients in your practice who are looking for new technology and want to be informed of all their options.

Currently 43% of the 79 million adults over 50 use the Internet 11-30 hours per week.^1,2 These adults utilize online information about their eyes and will typically come into your office with printed pages of questions. According to research from MarketScope, the amount of cataract surgeries are expected to continue to grow: In 2008, 3.092 million cataract surgeries were performed; in 2012, 3.490 million cataract surgeries are expected to be performed, and by 2015, that number is expected to grow to 3.851 million.³

Will YOU be ready to take care of these patients?

Cataract surgery today IS refractive surgery. We have bridged the gap between refractive and cataract surgery. Today, the goal of cataract surgery is not just to provide a clear lens to see through. We are expected to provide a specific refractive outcome after surgery. Patients expect to see clearly in the distance without a correction.They expect better vision and a fast recovery.

O.D.'s Role in Cataract Surgery

As optometrists, we have long-term relationships with our patients, which make us uniquely able to discuss with the patient the appropriate options for cataract surgery. We can convey this knowledge to the surgeon, so the surgeon understands which lens may be appropriate. We need to educate the patient about possible visual outcomes as well as possible complications. Our job is to manage the patient expectations so as to underpromise and over-deliver to them. We are in a service economy, and unless we create a true life enhancing experience for our patients, they will seek care in other offices.

We need to analyze the patient’s prescription and determine the amount of residual astigmatism we expect to find. Pre-operative keratometry readings are important to take. Once the crystalline lens is replaced, the lenticular astigmatism present pre-op will be gone. If there appears to be greater than three quarters of a diopter of corneal astigmatism, it is time to start the discussion with the patient about possible solutions.

In our office, I have found the discussion of deluxe lens options to be quite straightforward. Patients understand astigmatism will decrease their acuity. Patients also understand that they are not able to read without the help of some near correction. While the multifocal option involves lengthy discussions and education, I have found our astigmatic patients embrace the idea of toric IOLs. This is similar to our soft lens patients with moderate amounts of cylinder; they readily accept toric soft lenses. The patient also readily understands that the more sophisticated design has an additional cost associated with it.

Pre-op Considerations

Pre-op considerations for toric IOLs are no different than those for other types of lenses. Careful case histories are important.It is especially imperative to get a complete health history as well as all medications that are taken. Some health concerns can influence the type of lens you would recommend, the type of procedure and where it should take place. Certain patients at high risk should only have the procedure done at a hospital surgery center instead of an officebased center.

As mentioned, medications are also critical; patients on medications such as Flomax (Boehringer Ingelheim) are at risk for floppy iris syndrome if the surgeon does not take proper precautions. Many seniors today are on antidepressants, and if they are have issues with depression or other mental disorders, they may not be an ideal candidate for a deluxe procedure, or possibly any operation. Conditions such as diabetes, heart disease and arthritis need to be evaluated for severity.Conditions that may affect the healing process must be considered. Diabetes, lupus and many others can cause problems.

Careful keratometry readings and topography need to be performed. Slit lamp biomicroscopy is a critical test to perform with and without staining. Dry eyes are very common in this age group, and any anterior segment disorder may affect the resultant vision. Meibomium gland dysfunction is one of the most under-diagnosed problems in today’s patients. Aggressively treat any meibomium gland disease and concurrent dry eye problem. We are currently utilizing Azasite (Inspire Pharmaceuticals, Inc.) b.i.d., OU for one week and q.d. for two more weeks, accompanied by 20mg doxycycline b.i.d. for 30 days and q.d. for 30 days more. We add a steroid antibiotic combination drop such as Tobradex (Alcon) or Zylet (Bausch & Lomb) q.i.d. for two weeks. Hot compresses and lid scrubs b.i.d. complete the aggressive regime. This treatment has worked in the vast majority of our patients. We utilize Restasis (Allergan) as well as artificial tears aggressively, too. Remember, the most beautiful surgery will be ruined by a poor tear film, as it will cause distorted optics for your patient. Finally, a dilated fundus exam is important to rule out any possible retinal defect, especially macular changes. If any early macular change is seen, the patient may not be a good deluxe lens patient.

Benefits of Toric IOLs

Our practice has truly embraced toric IOLs. We have found that the cylinder corrected closer to the nodal point of the eye yields excellent optics for our patients. Most of our patients prefer to have one procedure to address their cataract and astigmatism rather than returning for a secondary surgery such as LASIK. I believe we are minimizing potential complications by taking care of the cylinder in one procedure. Patients remark how crisp their vision is with these lenses and enjoy only having to wear readers. We can also use these lenses in a monovision form as well as possibly performing a secondary multifocal refractive technique. It also won’t be long until we see a toric form of multifocal IOLs, too.

Toric IOLs on the Market

There are currently two toric lenses available to our patients, the STAAR Toric (STAAR Surgical) and the AcrySof Toric (Alcon). The STAAR Toric comes in two models, correcting 1.50D or 2.25D of astigmatism. The early model of the STAAR lens, the TF, was plagued by rotation stability problems. The latest model, the TL, seems to have improved the stability of the lens. The STAAR material is a silicone and is a one-piece design.

The AcrySof Toric currently comes in three models, correcting approximately 1.00D, 1.62D and 2.25D of astigmatism. The AcrySof lens is built on the same platform as the AcrySof aspheric lens. The aspheric optics in the lens help to neutralize the positive spherical aberration from the cornea and thereby give the patient crisper vision at all distances under most any condition. These lenses work by decreasing positive spherical aberration which increases contrast sensitivity for the patient. This will improve the person’s reaction time for such tasks as stopping a car. Our patients are amazed at how much better their night vision is with these lenses.

The high quality optics obtained by the AcrySof Toric can be attributed to the aspheric optics as well as the unique design to create rotational stability. The Alcon acrylic material has a “tacky” surface quality that promotes short-term stability and generates fibronectin and other natural tissue adhesives that stabilizes the implant to the capsule bag over the long term. The design of the haptics also helps to stabilize the lens. The haptics are open-loop modified L-haptics with three reference dots on each side that mark the axis of the cylinder on its posterior surface.Chang reported the mean rotation for the Acrysof Toric was less than four degrees from initial alignment 12 months postoperatively.⁴ The silicone surface of the STAAR lens is much more slippery, and therefore tends to rotate more.

Surgical technique proceeds as with other types of cataract surgery. Reference marks are placed on the cornea to help align the astigmatism.

Phacoemulsification is performed and the foldable toric lens is inserted with a Monarch-II injector.

The lens is rotated approximately 15 degrees off axis before the ophthalmic viscosurgical device is removed.

After the removal, the lens is then rotated into position and aligned with the reference marks.

Post-Op Care

Postoperative care is also similar to other types of IOLs.Our typical treatment is Vigamox (Alcon) q.i.d. for two weeks, Omnipred (Alcon) q.i.d. for two weeks and Xibrom (Ista Pharmaceuticals) q.i.d. for two weeks. Visits are performed at one day, two weeks, six weeks and three months. Tonometry, slitlamp, and a manifest are performed at each visit. A dilated exam is done at six weeks to check on the alignment of the lens. If there is a decrease in vision due to rotation of the lens, the surgeon can go back into the eye through very small incisions and rotate it back.If there is still residual correction, the surgeon can elect to do a laser procedure on the cornea to get the final Rx. Typically these patients need only a reading prescription after surgery and are happy to only have to deal with readers.

Case Reports

Let’s review some actual patient results from our office:

• WM is a 62-year-old white male who came to our office to inquire about refractive surgery. He feels like his vision is changing, and his eyes are not working as well together as in the past. He is an attorney who works many hours at a computer. Refraction shows: OD: +4.00 – 3.25 x 100, 20/20 and OS: +2.50 – 1.25 x 92, 20/20. Keratometry readings are: OD:45.25/43.25 @92, OS: 44.50/43.62 @ 92. Slit lamp biomicroscopy showed a clear cornea but nuclear sclerosis was evident OU. Due to the patient’s Rx and lenticular changes, we recommended a RLE procedure over LASIK. We felt the quality of vision would be better with a much more long term result with the RLE. Surgery was done on each eye with the following lens choice: OD: Toric SN6AT3 24.5 @ 11, OS: Toric SN6AT3. Surgery proceeded as planned. The three month postop visit showed excellent vision with little residual power. Refraction: OD: +0.25 -0.75 x 25, 20/20+, and OS:-0.25DS, 20/15. Uncorrected acuity:OD:20/25+, OS: 20/15-. The patient only wears readers for his near work and is quite pleased.

His symptoms of eyestrain have completely abated.

• LM is an 81-year-old white male who came to us complaining of blurred vision in his right eye. He had previous cataract surgery in the left eye by another surgeon. Refraction shows: OD: -0.50 – 1.25 x 92, 20/30 and OS: -2.50DS, 20/40. Slit lamp revealed a grade 1+ cataract in the right eye and grade 2 posterior capsular opacification in the left eye. Early macular changes were noted in the left eye. The lens chosen for the right eye was an Alcon Toric SN6AT3 18.5 @ 143. Surgery proceeded as expected and a YAG capsulotomy was done on the left eye. The six week visit showed excellent vision in the right eye and some improvement in the left. Uncorrected visual acuity was:OD:20/25 and OS:20/200. Refraction was:OD:+0.25 – 0.25 x 60, 20/25 and OS:-2.25 – 0.25 x 90, 20/30+. LM is very pleased with the result in his toric IOL eye.

The ability to correct astigmatism in cataract surgery is a great advance for the improvement of our patient’s lives. The advent of the new deluxe lens options has made cataract surgery truly a refractive procedure. Toric aspheric IOLs greatly improve the optics to function in a new world of high tech devices. Small incision surgery with these IOLs are providing both excellent results for our patients with very quick healing times.

1. Jupiter Communications.
2. 2002 U.S. Census Bureau.
3. MarketScope (4/09)
4. Chang, DF. J Cataract Refract Surg. 2008 Nov;34(11):1842-7.

Dr. David Geffen is currently director of optometric and refractive services at the Gordon & Weiss Vision Institute in San Diego, California. He has lectured and written extensively on contact lenses, refractive surgery procedures and intraocular lenses. He is the current treasurer for the Optometric Council on Refractive Technology (OCRT). He is currently serving as the Chair for the Optowest Advisory Panel for the California Optometric Association. Dr. Geffen has conducted dozens of contact lens related studies for many manufacturers and has served as an industry consultant for several companies over the years.

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