Phaco techniques, technology hot topics at Hawaii meeting

KOLOA, Hawaii — The latest in phacoemulsification techniques and technology, as well as advances in the treatment of glaucoma, oculoplastics and refractive surgery, were among the topics presented here at Hawaii 2001, the Royal Hawaiian Eye Meeting, sponsored by Ocular Surgery News in conjunction with the New England Eye Center. More than 450 physicians attended the meeting on Kauai Island.

William J. Fishkind, MD, discussed the newest phaco technology. Using occlusion, taking care to limit surge and understanding the new technologies may help surgeons reduce the occurrence of adverse events during phaco, Dr. Fishkind said.

“We need to move away from old technology and move forward toward new technology, using occlusion now to maximize our efficiency,” he said. “We are in an exciting time when it comes to phacoemulsification. It’s still the No. 1 procedure we’re all performing, and certainly if we’re going to do this we want the equipment to do the job properly.”

One pump that Dr. Fishkind said he favors is the Concentrix model used in the Millennium phacoemulsifier (Bausch & Lomb). This pump can be programmed to act like a peristaltic or venturi pump. It also has a setting that allows the surgeon to command vacuum level setting or flow mode by controlling rise time.

“We can prevent surge in pre-occlusion by decreasing vacuum flow using a chamber maintainer or the dual linear foot pedal of the Millennium machine,” Dr. Fishkind told meeting attendees. He said chamber maintainers do not always work well.

“We can prevent surge in occlusion by using the ABS system that Alcon has developed,” he added.

Treating LASIK striae

Marguerite B. McDonald, MD, of Tulane University, discussed LASIK complications. Although there has been little published about treating flap striae, she said, there are some things that can be done.

“There’s no real agreement amongst the experts regarding how to treat the striae,” she said. “Some experts claim never to have seen striae.”

Dr. McDonald said to manage striae she lifts the edge of the flap at the slit lamp with a flap spatula.

“Even though this is a procedure where you are going for striae, often when you have striae you also have epithelial ingrowth, so I inspect the undersurface of the flap and the bed for epithelial cells and if they are there, I remove them with a Tooke knife,” she said.

Next, Dr. McDonald says she replaces the flap and irrigates the interface with sterile, distilled water.

“But I aspirate it away immediately as if it were a toxic solution and I do this with an aspirating speculum, or an assistant using an infant feeding tube attached to a 50 cc syringe,” she said.

After Dr. McDonald strokes the flap back into to place, she creates a central defect on the flap with the Tooke knife.

“Then I take several more drops of the sterile distilled water and I put them on top of the epithelial defect for 3 to 5 seconds and then irrigate it all away vigorously because I don’t want to damage the remaining corneal and conjunctival cells,” she said.

After this, she irrigates the surface again with balanced salt solution and then adds a soft bandage contact lens. Finally, she gives prednisone 80 mg for at least 4 days.

Treating post-LASIK dry eye

Though treating patients with dry eye after LASIK can be difficult, one surgeon said he has found a way to make it easier to deal with.

“We should be pretty aggressive with non-preserved tears, especially with carboxymethylcellulose, and be very aggressive with plugging,” said Frank A. Bucci Jr., MD, of Wilkes-Barre, Pa.

According to Dr. Bucci, post-LASIK dry eye is caused by decreased tear production secondary to decreased corneal sensation.

“Early on, just after LASIK in the first days and week perhaps, the symptoms are related more to sensation because of the linear epithelial defect around the edge of the flap,” he said. “There are actually exposed nerves there. But later on, more importantly, the symptoms become related to vision. The patients have an intact surface and they don’t necessarily feel sensory findings, but they have fluctuating or decreased vision, depending on how compliant they are with their tear drop.”

Dr. Bucci said that that treating the eye with artificial tears and plugs is good way to fight post-LASIK dry eye.

“My recommendation preoperatively would be to vigorously treat ocular surface disease with non-preserved or transiently preserved tears and punctal plugs. Intraoperatively, minimize topical anesthetics, minimize preservative, minimize toxic corneal markers. You want to lubricate the corneal surface before the microkeratome pass and you can even lubricate the microkeratome head. Postoperatively, I recommend a viscous tear for at least 24 hours, every hour while awake for 24 hours.”

Wavelight machine

A tracker-assisted excimer laser, the Allegretto, made by the German company Wavelight, is performing well in U.S. clinical trials, according to Charles R. Moore, MD, of Houston.

“Internationally, I think this is probably one of the best units that can be found anywhere for excimer laser,” he said. “Those of you who don’t have to work with the (Food and Drug Administration) in the United States can get this through Coherent, who is now distributing the machine for Wavelight.”

Dr. Moore said that he has been satisfied with the results has seen from the machine in clinical trials.

“We’ve been very happy with the mean best corrected visual acuity, and the scattergram was good,” he said. “We had a little bit of undercorrection in the cylinder, almost across the board. That’s one of the things that was changed when the laser was modified.”

According to Dr. Moore, the machine has been very efficient.

“What we’ve done is seen very, very smooth ablations,” he said. “The tracker has not failed in any one of the 74 cases, resulting in as good or better visual acuity in all but one patient.”

Laser system slower

Laser cataract removal was also discussed. According to I. Howard Fine, MD, of Eugene, Ore., laser cataract removal still has a long way to come before surpassing phacoemulsification.

While laser cataract systems will improve over time, at the present they leave something to be desired, he said.

“I believe all of these systems will improve increasingly, and that’s why they continue to generate enthusiasm on my part,” Dr. Fine said. He compared the Phacolase (Asclepion-Med itec) to standard ul trasonic phaco.

While traditional ultra sound phaco machines scored better in efficacy and fluidics in Dr. Fine’s estimation, the laser system and ultrasonic systems are somewhat similar in regard to safety. Clinical applications of the two types of machines are similar, but conventional phaco machines are quicker, he said.

“Surgical time is much slower for laser than for ultrasound and that’s very important because time in the OR is convertible to cost in producing surgery,” Dr. Fine said.

He also said laser cataract systems have not so far proven less costly to purchase than conventional ultrasound.

Understanding glaucoma patients

David L. Epstein, MD, of Duke University Eye Center, discussed care and treatment of glaucoma patients. Better care and sensitivity are things that most patients with glaucoma want from their physicians, Dr. Epstein said.

“If I had glaucoma, it’s very important that you listen to what I have to say,” he told attendees of the meeting. “Studies have shown that we tend to cut off our patients after 23 seconds, and if I had glaucoma, that would not be long enough for me.”

Dr. Epstein said that if he had glaucoma, he would want to be treated the same way a physician would treat himself or herself.

“If I had glaucoma, I would want an ophthalmologist who would treat me as he or she would their own eyes,” he said. “We can argue all we want about this pres sure, that pressure, but if the ophthalmologist can look me in the eye and say, ‘This is what I’d do if this were my eye,’ that’s the kind of physician I would want.”

Dr. Epstein also said he would want his physician to be more understanding when it came to putting drops in the eye.

“People have great difficulty in doing this, and the current inverted bottle is very difficult to use for our elderly patients,” he said. “There have been all kinds of ways to try to get around this.”

Combination drugs in glaucoma

Combination drugs may play an important part in the future of glaucoma therapy, said Eve J. Higginbotham, MD, of University of Maryland.

“It’s nice to brainstorm about these things because I do think combination drugs are very important,” she said. “I think they’ll play a greater role in the management of glaucoma patients in the future. One must consider the benefits of reduced frequency of medications and the potential downstream effects on compliance and toxicity, and also consider the potential reduction in dosing errors. Certainly we hope to have a win/win situation for both patient and physician so that we have better compliance to our medical regimens.”

Dr. Higginbotham said that certain drug combinations have already proven efficacious.

“Certainly efficacy has been well demonstrated in a number of studies re lated to the most commonly used combination drug today, and that’s Cosopt (dorzolamide HCl, timolol maleate ophthalmic solution, Merck),” she said. “In a randomized trial, it was shown that fixed combination dorzolamide-timolol was more effective than either of its components.”

She also said that this fixed combination is safe and effective and that the convenience of the combination drug helps with compliance.

She said other fixed combination drugs may be put forward in the future to take advantage of the complementary modes of action of certain drugs.

Surgical repair of entropion and ectropion

On the oculoplastics front, analyzing the cause of lid malposition and using a lateral tarsal strip procedure are helpful when planning and performing surgical repair, said William J. Lipham, MD.

“It’s important to analyze the etiology of the eyelid malposition, as well as its location, to determine which procedure should be performed,” he said. “You should remember that the lateral tarsal is a very versatile procedure that can be used in most situations with associated horizontal eyelid laxity, and is a nice foundation for other types of surgery.”

According to Dr. Lipham, when evaluating a patient with involutional ectropion, it is important to determine which part of the eyelid is involved.

“Medial ectropion is different from lateral ectropion and should be managed differently,” he said. “These pat ients with medial ectropion will typically have problems with tearing and epiphora, while those with lateral canthal dystopias usually do not.”

When selecting a procedure to correct an eyelid malposition, Dr. Lipham said it is important to recognize which lamella is involved.

“While entropion typically involves the entire length of the lower eyelid, ectropion can be more regional in na ture, and as such you need to recognize if it’s medial or lateral and adjust your surgery to correct this situation,” he said.

Ptosis repair

Dr. Lipham also discussed ptosis repair. Again, he said, determining the cause of the condition is important. Levator function can be used by the surgeon as a guide for selecting the best procedure, Dr. Lipham said.

“It’s important to recognize the etiology of the ptosis, as well as understand what are the documentation requirements for insurance purposes,” he said. “Levator function should also be taken with great care because it’s the single measurement that you will probably use to determine what is the most useful procedure for each patient. And you should keep in mind that the versatile levator aponeurosis is an excellent procedure to correct ptosis, as it works well in most cases that you will encounter in clinic.”

A complete ocular examination is necessary in all patients to determine the underlying causes of the ptosis, he said.

Most surgeons who use levator apo neurosis advancement to correct ptosis get positive results, Dr. Lipham said.

Reimbursable test for dry eye

On the dry eye front, a new test called the TouchTear Micro Assay system (Touch Scientific) for dry eye is available to be done in the office and provide accurate results, according to Henry D. Perry, MD.

“This is real science,” he said. “If anybody really wants to introduce real science into their office, they can buy this machine. Basically, at this time, it just presents data on lactoferrin and IGE, but the future looks bright.”

Though the machine does produce accurate results, it takes some time for the test to be performed.

“I would say it probably takes a technician about 2 hours to learn how to do this test adequately,” Dr. Perry said. “The time initially is about 20 minutes per patient, and then after about 10 to 20 patients, they can get to about 10 minutes per patient. So there is a 10-minute tech time per patient for this level of determination. But it is highly accurate.”

Another benefit of the machine is that it is reimbursable.

“Medicare at this time in New York allows $17.83,” Dr. Perry said. “It does not matter whether you do one eye or both eyes, and since you have the agent cost per card, it’s more expensive to do two eyes and your profit decreases.”

For Your Information:

• Next year’s meeting, Hawaii 2002, will be held at Jan. 20-25, 2002, at Hilton Waikoloa Village, on the Big Island. For registration information, call (856) 848-1000, or send an e-mail to osn@slackinc.com.