Royal Hawaiian Eye meeting highlights glaucoma, cataract, refractive surgery, pediatrics

LIHUE, Hawaii — Presenters here at Hawaii 2004, the Royal Hawaiian Eye Meeting, stressed the importance of learning about alternative therapies for glaucoma, recommended trying a second prostaglandin if the first is unsuccessful and shared new developments in cataract and refractive surgery.

Alternative glaucoma therapies

Use of alternative therapies is becoming more common, and physicians should educate themselves about the good and bad effects of these products so that they can intelligently counsel patients, said Robert J. Noecker, MD.

“There is a vast amount of information on alternative therapies and lifestyle modifications available to patients, but very little of it has substantial evidence behind it,” Dr. Noecker said. “We have to understand what they are doing to themselves and keep them out of trouble.”

Dr. Noecker outlined some of what is known about alternative therapies and lifestyle modifications in relation to glaucoma. He said some lifestyle modifications may be beneficial for glaucoma patients. Regular daily exercise, for instance, has been shown to lower IOP by about 5 mm Hg. Yoga, on the other hand, has no proven benefit on IOP, and in fact inverted positions such as the headstand can increase IOP.

Vitamins, while they may have other health benefits, for the most part have no effect on IOP, Dr. Noecker said. Vitamin C has been shown to lower IOP, but only with megadoses that can have systemic side effects. Vitamin E might be a beneficial adjunct to filtering surgery, he said, but this must be balanced against an increased risk of excessive bleeding.

Some herbs may have an effect on glaucoma, but caution is necessary with their use, Dr. Noecker said. Ginkgo biloba may increase blood flow and may have some neuroprotective effect, but it also affects bleeding and should be avoided in patients on Coumadin (warfarin, DuPont Pharmaceuticals) and some other drugs.

Marijuana has been shown to have an IOP-lowering effect in 60% to 65% of patients, but its effect is short-lived, he said. “Some patients who ask about it kind of brighten up when you tell them they would have to take it every 3 to 4 hours to have a continued effect,” Dr. Noecker joked.

The systemic side effects of marijuana and the health effects of chronic smoking are enough evidence to recommend against its use, in addition to the fact that it is illegal, he said.

There are, however, ongoing efforts to develop topical cannabinoids – compounds related to THC but without the euphoric effects – that are showing promise, he said.

Family history crucial in glaucoma

Always inquire about family history when diagnosing a patient with glaucoma, said John R. Samples, MD.

“If I have one take-home message for you, it is if high pressure open-angle glaucoma appears to be a single disease, that is not the case. Inquire about family history” when making a clinical diagnosis, Dr. Samples said.

Dr. Samples further explained that the open-angle glaucomas are a group of diseases with different clinical characteristics, so the physician should be as thorough as possible when taking the family history.

During a presentation on genetics in glaucoma, he said, “Genetic testing will allow us to predict a patient’s clinical behavior.”

He added that within the next year, more results on neuroprotection with gene therapy will become available. “We are in an era of genetic therapy,” Dr. Samples said.

Applying glaucoma research

Clinicians should apply newly published clinical information to their daily care of glaucoma patients, said Anne L. Coleman, MD. She said all clinicians should practice evidence-based medicine.

Dr. Coleman said physicians should consider the findings of the Ocular Hypertension Treatment Study (OHTS) and the Early Manifest Glaucoma Trial (EMGT) in treating their patients. She explained that evidence-based medicine can help physicians calculate risk-benefit ratios, such as the number needed to treat (NNT) and the number needed to harm (NNH).

She said that the NNT takes into account the baseline risk of an outcome in a population, and the NNT may be helpful when a clinician is deciding whether to treat an individual patient. She said it is easy to compare the NNT with the NNH from the same study.

For example, following the results of OHTS, she said, “If you treat 96 patients with ocular hypertension for an average of 5 years, you will prevent glaucomatous optic nerve damage in 6 patients and cause 2 patients to have cataract surgery.”

In another example, Dr. Coleman said, “if you treat 18 patients similar to those in the EMGT for an average of 6 years, then you will prevent glaucomatous optic nerve progression in six patients and cause three patients to have cataract surgery.”

Furthermore, OHTS found that for each 1 mm Hg higher IOP at baseline, there was an approximate 10% increased risk of glaucomatous progression. In the EMGT, a decrease in the average IOP of 1 mm Hg was associated with approximately a 10% decreased risk of glaucomatous progression.

These studies show that “lowering IOP is important and can be expected to decrease risk of glaucomatous progression,” Dr. Coleman said. “It just takes your clinical judgment.”

Switching prostaglandins

If a glaucoma patient is unresponsive to one prostaglandin-type drug, the physician might consider switching the patient to a different prostaglandin rather than adding another drug to the patient’s treatment regimen, a speaker here suggested.

David Tingey, MD, FRCSC, discussed the characteristics of the four available prostaglandin-based glaucoma drugs currently on the market: Xalatan (latanoprost, Pfizer), Lumigan (bimatoprost, Allergan), Travatan (travoprost, Alcon) and Rescula (unoprostone, Santen).

Dr. Tingey noted that the first three of these drugs are all PGF2-a analogues, and as such share similar chemical structures and characteristics. Their mechanism of action is thought to be the increase of uveoscleral outflow. They are similarly efficacious, with the ability to lower IOP by 25% to 35%, Dr. Tingey said. Unoprostone, a docosanoid, is somewhat distinct from the other three in structure, in that it lowers IOP by only about 15%, he said.

Dr. Tingey noted that in studies comparing the efficacies of latanoprost, bimatoprost and travoprost, the results are “variable and contentious.” A 6-month study by Noecker and colleagues found bimatoprost to be superior to latanoprost. A 12-week study by Parrish and colleagues of all three drugs found no statistically significant differences. “All three drugs are very effective,” he said. “If there is a difference in efficacy, it may be hard to show.”

Dr. Tingey said he tends to choose latanoprost for “treatment-naïve” patients and any of the three PGF2-a medications for patients who are on multiple medications.

Dr. Tingey suggested that if patients do not respond to one prostaglandin, physicians might try switching the patient to another prostaglandin before adding another drug to the regimen. “If one prosta drug does not achieve your target, consider trying another,” he said. He cited a study by Gandolfi and colleagues, in which patients who were uncontrolled on latanoprost achieved lower IOPs when switched to bimatoprost.

Macular disease in cataract

Diminished visual acuity due to existing macular disease is the most common reason for patient dissatisfaction after cataract surgery, according to Carmen A. Puliafito, MD, a retinal surgeon. “I thought hard about this before I said it is ‘the most common complaint’,” Dr. Puliafito said, speaking at a session on cataract surgery and IOLs. “Make sure the macula is normal – and I do mean normal – before you operate.”

Dr. Puliafito said an optical coherence tomography (OCT) study should be obtained for all patients with suspected retinal pathology. The OCT can identify the presence of preretinal membranes and other macular pathology that might affect the outcome of cataract surgery, he said.

Patients with existing macular problems may benefit from cataract surgery in some cases, he said, but it may be helpful to lower the visual expectations of these patients.

“We are at the forward edge of a macular degeneration epidemic,” Dr. Puliafito said, as the baby boomer generation moves into old age. He said AMD is due in part to genetic disposition, but physicians must consider what they and their patients can do to modify the risks of developing the condition.

Currently, vitamin supplementation and reduction of blue light transmission to the retina are the only such options, he said. He advised cataract surgeons to consider implanting blue-light-blocking IOLs, such as the Alcon AcrySof Natural (Ft. Worth, Texas), in patients who might be predisposed to AMD.

Dr. Puliafito acknowledged a financial interest in the OCT technology, which he helped develop.

Array for RLE

The Array IOL (AMO, Santa Clara, Calif.) provides good vision at distance and near in both hyperopes and myopes after refractive lens exchange (RLE), according to Frank A. Bucci, MD. The risks of retinal detachment in myopic eyes after RLE should be reexamined in light of recent data, he said.

With a mean follow-up of almost 1 year, the Array provided uncorrected distance vision of 20/40 or better in 100% of 110 myopic patients and 97% of 161 hyperopic patients, Dr. Bucci said. At the same time, 87% of the myopes and 92% of the hyperopes saw J3 or better at near without correction, he said.

Dr. Bucci said he used astigmatic keratotomy (AK) at a 10-mm optical zone to correct astigmatism in any patient with 0.25 D or more of corneal astigmatism at no sooner than 3 weeks after RLE. Fifty percent of the myopes in the series and 16% of the hyperopes underwent AK. In the myopic eyes, a mean of 1.08 D of astigmatism before any surgery was reduced to 0.46 D after clear lens exchange and AK. In the hyperopic eyes, a mean of 0.65 D of astigmatism before any surgery was reduced to 0.36 D after RLE and AK, he said.

There was no loss of vitreous at the time of surgery, and there were no cases of retinal detachment or cystoid macular edema postoperatively in this series of eyes, Dr. Bucci said. He noted that reports from 10 or more years ago described a high incidence of retinal detachment in myopic eyes after RLE. But he said that with modern methods of clear corneal phaco and careful patient selection – including limiting surgery to patients with less than 25 mm axial length – a reassessment of the risks of the procedure in myopes is warranted.

Dr. Bucci said patient selection is one of the most important factors in the success of RLE with the Array. “I could do a whole hour lecture on what characteristics to be wary of in your patients,” he said.

In general, patients with demanding, introspective or “type A” personalities, and those who do a lot of near work, such as engineers, should not be candidates, he said. A strong preoperative desire for spectacle independence is highly correlated with success, he said.

Refractive surgery dissatisfaction

A survey of patients dissatisfied with the outcomes of refractive surgical procedures identified “a spectrum of complications” that contributed to the visual complaints, said Terrence P. O’Brien, MD. The survey was conducted among patients seeking consultations at the Wilmer Eye Institute.

Among the notable findings of the survey were these: More than 50% of patients had bilateral problems. The number of previous surgeries was not correlated with worse outcomes. Irregular astigmatism was most commonly associated with loss of best-corrected visual acuity.

Many of the dissatisfied patients had good corrected visual acuities, Dr. O’Brien said: 56% of eyes had a BCVA of 20/20 or better, and more than 90% had a BCVA of 20/40 or better.

The survey included 161 eyes of 101 patients, Dr. O’Brien said. Average time between the patients’ first surgery and their consultation at Wilmer was slightly more than 2 years, he said.

The most common complaints were blurred distance vision (59%), glare (27%), dry eyes (21%) and blurred near vision (19%), Dr. O’Brien said. LASIK or LASIK enhancement were the most common types of surgery reported.

In the consultations at Wilmer, nonsurgical treatment was recommended for 47% of the patients, Dr. O’Brien said. These treatments included lubrication, glasses, soft and rigid contact lenses and punctal plugs. Surgical options, recommended to 53% of the patients, included LASIK or LASIK enhancement, flap lifting and irrigation, and corneal transplant.

In a large number of patients (33% of eyes), the recommendation was to wait for future technology to become available, Dr. O’Brien said.

New Amadeus software, rings

Advanced Medical Optics’ Amadeus microkeratome is now available with new software and rings, according to Kerry D. Solomon, MD.

He described new features of the Amadeus microkeratome, including a new font on the machine that makes reading the display easier. He also discussed the new feature of acoustic progression of the vacuum level. In addition, a new option for Asian eyes introduces an altered curvature of the instrument, he said.

At an AMO-sponsored press conference held here during Hawaii 2004, Dr. Solomon said the reliability of the Amadeus is “the reason it’s growing.”

Diffractive-refractive multifocal

The Alcon AcrySof ReStor diffractive-refractive multifocal IOL demonstrated an improvement in near vision and no decrease in distance vision compared to a monofocal IOL, Dr. Solomon reported.

Dr. Solomon described a study in which 340 patients were implanted bilaterally with a three-piece AcrySof ReStor multifocal IOL and 225 were implanted with the traditional one-piece monofocal AcrySof. He said distance vision did not decrease with the ReStor compared to the monofocal IOL, and near vision was markedly improved.

“Near vision is simply spectacular with this lens,” Dr. Solomon said at an Alcon-supported symposium held during Hawaii 2004.

Dr. Solomon explained that a benefit of the ReStor lens is that it meets the needs of patients who do not want to wear glasses while going about daily activities such as reading, driving and sewing. In patient satisfaction questionnaires, “most patients say they would have this lens implanted again,” he said.

He added that the ReStor provides significant advances “like I’ve never seen before in lens technology.”

Ocular pulley and strabismus

The extraocular muscles represent a different class of muscle in regard to function, structure and gene, according to Mitchell B. Strominger, MD. Knowledge of the extraocular muscles (EOM) can help in the treatment of strabismus, he told attendees.

Dr. Strominger described the EOM as consisting of two layers: a global layer continuous with the tendon and inserting on the eyeball, and an orbital layer inserting a connective tissue ring forming the EOM pulley. This pulley controls the path of the EOM, Dr. Strominger said, and serves as the EOM’s functional origin.

“Treatment of pulley disorders may be required for certain forms of strabismus,” he said.

Align esotropia patients early

In a small study of patients with congenital esotropia, there was no significant difference in the proportion of patients who achieved fusion when alignment surgery was performed within the first 24 months of age, said Malcolm R. Ing, MD.

“My take-home message is you must align by age 2,” Dr. Ing said.

He described a study of 90 patients with congenital esotropia who were aligned by age 2. Fusion was present in 94% of patients who were aligned by age 2 and 94% of patients with 21 months or less of misalignment. Dr. Ing said there was no statistically significant difference among those aligned by 6, 12 or 24 months of age. Additionally, there was no significant difference found among those aligned with duration of misalignment of 6 or less months, between 7 to 12 months or between 13 to 21 months.

Adult diplopia exams

Adult patients with diplopia need a thorough history and examination to determine the cause of the diplopia and the proper treatment course, according to Dr. Strominger.

“I know that there are many of you who are seeing pediatric strabismus patients all day, and then you’ll have an adult patient come in who says, ‘Doctor, I’m seeing double.’ So then I look at my watch and say to myself, ‘Oh, boy, I’m going to be with this patient for at least 1 hour until I can figure out what’s going on’,” he said.

Dr. Strominger said the physician must check for past strabismic and trauma history; past ocular surgical history, especially cataract surgery; and any systemic conditions, such as thyroid orbitopathy, optic neuropathy and Parkinson’s disease. He added that diplopia should be considered a neuro-ophthalmic condition “until proven otherwise.”

Treatment can include prisms, strabismus surgery or, as a “last resort,” Bangerter occlusion foils, an occlusion patch or a cosmetic occlusive contact lens, Dr. Strominger said.

Dry eye sunglasses launched

Sunglasses designed specifically for dry eye patients made their debut here at the meeting.

Panoptx Dry Eyewear “deliver the best attributes of a goggle with the style and comfort of sunglasses,” according to company officials. While wearers are in motion, the sunglasses protect their eyes from wind, heat and sun with a foam eyecup that seals to the skin and protects the eye. This eyecup seal is covered with fleece that keeps perspiration away from the eyes and keeps the eyes cool, according to a press release.

Shareef Mahdavi, of the medical division of Panoptx, said the sunglasses were originally developed for motorcyclists who needed to keep dust and other particles out of their eyes. Mr. Mahdavi said the concept was adapted to a similar model for dry eye patients.

Mr. Mahdavi described a study conducted last year by Richard L. Lindstrom, MD, and Douglas Weberling, OD, on 100 patients. The study found that the Panoptx Orbital Seal alleviated nine common symptoms of dry eye, including burning, stinging, grittiness, dryness and sensitivity to light, according to a press release. On average, individual symptoms were reduced by 57% when patients wore the sunglasses.

In an interview, Mr. Mahdavi said practitioners can dispense the sunglasses in their offices. They sell for $85 to $185, he said. Prescription lenses are also available in powers ranging from +5 D to –5 D, he added.