December 2007

 

CATARACT/ IOL

 

Cataract trends in Asia


by EyeWorld Staff

 

The Asia-Pacific Society of Cataract Refractive Surgery (APACRS) held its annual meeting in Hanoi, Vietnam, September 28-29, 2007. It is amazing how rapidly the newest technology and techniques have come to this area. Although it’s true that there are many areas within the Asia-Pacific region that are underserved and have inadequate personnel, facilities, and equipment, the standard in the urban areas is as good as anywhere in the world, and the research being done by the practitioners in that area is as up-to-date and relevant as similar studies from around the world. EyeWorld reporters who covered this meeting have briefly summarized some of the sessions in this month’s column. What they didn’t summarize was the live surgery sessions in which Indian, Vietnamese, Asian and some European surgeons performed cataract and refractive surgery. Having attended most of the cataract sessions, I can say that the skills and the techniques were absolutely superlative. It was very satisfying to me, and to many other surgeons who have participated in teaching in the Asia-Pacific area, to see how rapidly the techniques and skills have been acquired by surgeons there, and to have a full sense of not only participating, but also being educated by our colleagues from the Asia-Pacific Society. For a long time many of us have felt that ophthalmology is indeed global. The extent to which ophthalmologists from all over the world cooperate with and teach each other has been remarkable. I’ve often thought that if the world leaders could get along as well as ophthalmologists we could, at last, achieve peace. I’m sure everybody will enjoy hearing about some of the aspects of the recent meeting and will perhaps consider attending next year’s meeting which will be held in Thailand. It would be educational and a delight to experience firsthand the magic of Thailand.

I. Howard Fine, MD, Column Editor

 
Professor Shimizu shares the inspirations behind his contributions to cataract surgery

Professor Espiritu highlights the incidence of CME

APACRS attendees watch live surgery

Attendees listen as ocular management trends are discussed

Various facets of cataract surgery were thoroughly reviewed at this year’s 20th annual Asia-Pacific Association of Cataract and Refractive Surgeons’ (APACRS) meeting in Hanoi. Speakers representing APACRS highlighted both innovations and trends in cataract surgery, but focused primarily on challenging cases and complications.

Techniques

Credit for contributions in the advancement of cataract surgery was given this year to Kimiya Shimizu, M.D., chairman, Department of Ophthalmology, Kitasato University, Japan, who delivered the Lim Lecture. Professor Shimizu began his lecture with a short video of Prof. Barraquer’s technique for intracapsular cataract extraction (ICCE) used in 1917. There are several similarities between the 1917 technique and the techniques used today, he said: the use of topical anesthesia and clear corneal incisions and non-use of sutures after surgery; however, Professor Shimizu emphasized two important differences: the size of the incision, and the use of IOLs.

He continued by stressing that apart from the obvious benefits of using IOLs, smaller incisions induce less astigmatism than large ones, allow quicker visual recovery, and reduce the risk of endophthalmitis. Unfortunately, smaller incisions make it more difficult to insert IOLs.

This led Professor Shimizu to develop the first injector for foldable IOLs in 1989, which allowed eye surgeons to insert IOLs with incisions as small as 2.7 mm. Further reductions in endophthalmitis risk were later achieved by introducing disposable injectors in 1993. However, there was one problem with using injectors: loading the IOL into the injector could be a problem, and sometimes resulted in damage to the lens, either on the haptic or on the optic.

In 2002, Professor Shimizu introduced the world’s first preloaded injector. Using the new device resulted in a decrease in damage rates from 2.99% to 0.14%.

The latest innovation introduced by Professor Shimizu was one that further reduced the risk of endophthalmitis: the viscoless preloaded disposable injector. Viscoelastic, he said, is not necessary for the insertion of IOLs during phaco. This particular innovation, he concluded, makes for a “safe, speedy and economical” form of cataract surgery In another session delineating advances in cataract surgery, Soon-Phaik Chee, M.D., Singapore National Eye Centre, compared the incision construction of the coaxial micro-incision with the bi-manual incision. She emphasized the key role of wound integrity in preventing endophthalmitis. Dr. Chee said that the coaxial microincision is more secure than the bimanual enlarged incisions and also recommended single-planed square incisions for better wound stability. Trends amidst advancements in cataract technology The majority of eye surgeons “still don’t recognize CME (cystoid macular edema) as the most frequent cause of visual decline” following cataract surgery, said Cesar Espiritu, M.D., Philippines. Available literature, he said, reports that up to 12% of low-risk cataract cases end up with CME. The second trend, presented by Victor Caparas, M.D., Philippines, was the rising rate of post-op endophthalmitis seen in recent years. Dr. Caparas said that a three- to four-fold increase in endophthalmitis rates has been seen in the last five years, bringing the rate up from one to two cases per thousand to three to four per thousand.

The two conditions constitute the most significant complications that continue to plague cataract surgery despite technological advancements that have significantly improved surgical outcomes in the last decade, including advanced intraocular lens (IOL) designs and torsional phacoemulsification.

For CME, Dr. Espiritu recommended giving Nevanac (nepafenac sodium, Alcon, Fort Worth, Texas), one to two days pre-op and up to four weeks post-op in low-risk patients, and one week pre-op and four weeks to one month post-op in high-risk patients.

An “optimal drug” for preventing and treating endophthalmitis, unfortunately, is yet to be found, and Dr. Caparas said that sterilizing the surgical area with povidone iodine is to date the only convincingly proven prophylactic measure, and is recommended by the American Association of Ophthalmology (AAO).

Still, Dr. Caparas said, this doesn’t mean that surgeons should just drop chemoprophylaxis and perioperative antibiotics. In this case, the fourth generation fluoroquinolones moxifloxacin and gatifloxacin currently appear to be the most promising agents. Both agents continue to show significant efficacy even against fluoroquine-resistant bugs.

Phaco complications

“First, do nothing,” said Sze-Guan Ong, M.D., Singapore. Dr. Ong was cautioning anterior segment surgeons against hasty action when confronted with a dropped nucleus at a symposium on the management of phaco complications.

While it’s often considered one of the most dreaded complications of cataract surgery, with an incidence of about 0.3 to 1.1% of phacoemulsification surgeries, Dr. Ong said that “dropped nucleus need not be a nuclear disaster.” Most patients have a successful outcome following prompt and correct—emphasis on correct—management.

The best thing to do when the nucleus drops into the vitreous is to just take a moment and assess the situation. “Do NOT chase the lens in any plane” in the anterior or posterior vitreous, not with the phaco probe, not with the irrigating probe, and definitely not with a lens loop. Posterior assisted levitation (PAL) is potentially disastrous, and Dr. Ong discouraged anterior segment surgeons from even attempting a limbal approach to retrieve the lens fragments.

An early referral to a vitreo-retinal specialist should be considered, but immediate vitrectomy isn’t always necessary. Immediate posterior vitrectomy does have the advantages of clear visibility and a faster visual recovery, while avoiding a second operation; however, said Dr. Ong, no significant association has been seen between the occurrence of complications and the length of time between the time of phacoemulsification and vitrectomy. However, he said, as a matter of convention, “try to do it within the first 14 days.” In the meantime, treat the inflammation and control the intraocular pressure.

Editor’s note: Drs. Shimizu and Chee have no financial interests related to their presentations. Drs. Espiritu and Caparas have financial interests with Alcon (Fort Worth, Texas). Dr. Ong has no financial interests related to his lecture.

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