September 2014

 

COVER FEATURE

 

Phaco and corneal comorbidities

Cataract surgery with corneal comorbidities


by Ellen Stodola EyeWorld Staff Writer

 
 

The timeline for doing calculations and surgery after treating a patients preoperative problems depends on the patient. The general rule, Dr. Hovanesian said, is whatever intervention you do, make sure the eye returns to normal before you take the next step.

 
aqueous tear deficiency

Untreated ocular surface disease, such as in this patient with advanced aqueous tear deficiency, reduces the accuracy of preoperative IOL measurements.

Source: John A. Hovanesian, MD

Treating corneal issues ahead of time can help surgeons complete a more successful cataract surgery

With patients set to undergo cataract surgery, it is important for surgeons to identify any pre- existing conditions. Corneal comorbidities, including dry eye, blepharitis, and epithelial irregularities, are important to address. John Hovanesian, MD, Harvard Eye Associates, Laguna Hills, Calif.; Christopher Ketcherside, MD, Kansas City Eye Clinic, Oerland Park, Kan.; and Charles Thompson, MD, The Eye Clinic, Lake Charles, La., discussed how they approach these patients.

Why treat before cataract surgery?

Whether were using a premium lens, doing refractive cataract surgery, or just basic correction of cataract, patients have come to expect that theyre going to have a high level of vision and in many cases spectacle-free vision after surgery, Dr. Hovanesian said. Were simply not going to achieve that if we have a tear film or an epithelial or corneal problem. When doing measurements at the level of the cornea, a mistake can cause errors in the IOL power. Mistakes are easy to make if you have an irregular tear film, Dr. Hovanesian said. Especially with multifocal lenses, it is important to distinguish between good and bad candidates because multifocal lenses already have one source that degrades contrast.

Dr. Thompson said that dry eye is one condition that would need to be treated before cataract surgery. When I approach a dry eye patient, I try to determine whether they are an aqueous deficient dry eye patient or an evaporative dry eye patient, he said. There are a number of risk factors, conditions, and medications that go along with these. Either way, the end result is an unstable tear film and can lead to changes in keratometry readings and inaccuracy of keratometry readings, Dr. Thompson said.

The most important thing is being accurate, Dr. Ketcherside said. People arent going to be happy if you put in the wrong lens or the wrong power lens or you dont deliver on what you say youre going to do.

Preferred regimen

Dr. Hovanesian said it is important to be vigilant for signs of potential problems before counseling the patient. What were concerned about largely is the biometry, he said. Sometimes the fastest way to tune up the ocular surface is to put a patient on steroids short term. Dr. Hovanesian said that he uses Lotemax gel (loteprednol, Bausch + Lomb, Bridgewater, N.J.) for this, but any steroid would be helpful. Loteprednol is good, he said, because it is kind to the ocular surface and is potent but not likely to produce pressure spikes. Ill do it for a week before they go through measurements, and that seems to make a big difference, he said.

Dr. Ketcherside said his preferred regimen varies depending on the patient and severity of problems. For mild cases, he may choose something as simple as having patients use artificial tears for 2 weeks and come back to repeat testing. For moderate disease, he may start the patient on Restasis (cyclosporine, Allergan, Irvine, Calif.), steroids, and artificial tears, and then try again in a month. If a patient has significant blepharitis issues, he will start with heat and lid hygiene and choose other treatments like doxycycline, AzaSite (azithromycin, Akorn, Lake Forest, Ill.), steroids, and omega-3s as necessary.

Dr. Thompson said that he goes through treatments of dry eye based on what category of condition the patient falls into. Lid hygiene becomes very important because a lot of patients who are dry, not only do they miss the aqueous component of their tear film, but they also miss the antibacterial effect of their tears, he said. When patients are dry, that leads to anterior blepharitis and a lot of bacteria on the lids, Dr. Thompson said. His approach is to use replacement tears to clean the lids so there is a good quality of tears around the eye. He then moves relatively quickly to punctal plugs and Restasis.

Dr. Thompson said it is helpful to have technologies like the test from TearLab (San Diego) to check osmolarity to ensure that treatment is moving in the right direction. He would also use the Schirmers test and lissamine green stain to see how the treatment is affecting the ocular surface.

For dry eye patients with meibomian gland dysfunction, there is an emphasis on lid hygiene. Using warm compresses and doing lid massages help with this condition, as does using lid wipes that promote meibomian gland function. Systemic medicine like doxycycline and the topical version of azithromycin can help as well. Once I feel like the patients comfort has improved and the testing has improved, I will usually go on with preoperative testing for cataract surgery, Dr. Thompson said.

When it comes to pretreating cataract patients with blepharitis, there are a number of options. With typical anterior blepharitis, erythromycin eyelid scrub once a night and a warm compress in the morning for about 3 weeks are options, he said.

If the patient is unresponsive to that, Dr. Thompson uses BlephEx (Rysurg, Palm Beach, Fla.), which is a way to clean the lids in the office and only takes about 5 to 10 minutes. Its been very useful in treating blepharitis patients preoperatively from a cataract standpoint or from a corneal surgery standpoint, Dr. Thompson said.

Other ocular surface abnormalities Cataract Surgery article summary

It is also important to be aware of other ocular surface abnormalities that a patient may have. Some of the most commonly missed, Dr. Hovanesian said, are anterior basement membrane dystrophy (ABMD) and endothelial guttae. He advised that all surgeons doing cataract surgery examine the cornea carefully. ABMD is a treatable condition, he said. If the irregularity causes staining or affects the central visual axis, try to intervene beforehand.

Among the things that Dr. Ketcherside looks for are pterygium, ABMD, Salzmanns, and dry eye. He also checks for scarring. Its better in the long run if patients know ahead of time that some of these conditions can impact the final outcome, he said.

Timeline

The timeline for doing calculations and surgery after treating a patients preoperative problems depends on the patient. Dr. Hovanesian said that for something like dry eye, there is usually a big improvement in just a couple of weeks.

But if the surgeon is taking off the epithelium to treat epithelial basement membrane dystrophy, it could take a couple of months for the cornea to return to its most pristine condition with predictable refractive behavior. The general rule, Dr. Hovanesian said, is whatever intervention you do, make sure the eye returns to normal before you take the next step.

Dr. Ketcherside agreed that the time between treating some of these issues and performing calculations and surgery depends on the patient. For mild dry eye that is treated with tears, he usually recommends about 2 weeks. If the condition is more serious, he may recommend the patient wait a month. Finally, when treating surface problems, Salzmanns, or pterygium, Dr. Ketcherside will usually wait 2 months for the patient to heal.

Can cataract surgery worsen dry eye symptoms?

Surgeons need to keep in mind that cataract surgery may worsen dry eye symptoms, although this is not always the case. Dr. Hovanesian said it is important not to scare patients away from surgery with unfounded fears, but he will have a discussion with patients to tell them how likely they are to encounter problems on a case-by-case basis.

Dr. Ketcherside lets patients with dry eye know preoperatively that this could affect their cataract surgery. I tell them that there shouldnt be a permanent lasting effect on their dry eyes from cataract surgery, he said, adding that there could be a mild increase in dry eye for several weeks to several months, but this usually goes away. By warning patients ahead of time, it helps relieve their anxiety, he said.

Dr. Thompson said that it depends on the severity of the dry eye in deciding what type of preoperative discussion is necessary with the patient.

Editors note: Dr. Hovanesian has financial interests with Allergan, Alcon (Fort Worth, Texas), and Bausch + Lomb. Drs. Ketcherside and Thompson have no financial interests related to their comments.

Contact information

Hovanesian
: drhovanesian@harvardeye.com
Ketcherside: cketch@gmail.com
Thompson: cthom1@gmail.com

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