This article is more than 5 years old. Information may no longer be current.
Novel cataract techniques presented at Asia-Pacific meeting
The APACRS meeting in Beijing brought together surgeons from throughout the Asia-Pacific region.
Click Here to Manage Email Alerts
BEIJING – Several innovative approaches to cataract removal were among the highlights of the Asia-Pacific Association of Cataract & Refractive Surgeons meeting here.
One surgeon described a sutureless technique for manual cataract extraction. Another introduced a coaxial phaco technique that he said would dim surgeons’ interest in bimanual phaco techniques. Still another explained how to use the irrigation and aspiration tip to perform capsulorrhexis.
These and other novel techniques were among the highlights of the presentations at the 18th meeting of APACRS, held here in conjunction with a meeting of the Chinese Cataract Society.
In his welcoming speech, APACRS President Graham Barrett, FRACO, FRACS, said the association has become “a vital hub for communications in the Asia-Pacific region.”
|
Dr. Barrett said that ophthalmologists, especially anterior segment surgeons, are continually faced with the emergence of new techniques and technologies, and that this constant change requires teaching and sharing of knowledge among colleagues. He noted the wide divergence in the degree of sophistication in the countries in the Asia-Pacific region, and he said one of the missions of APACRS is to overcome the barriers to delivery of care in the region.
“APACRS is dedicated to solving these problems,” he said.
The annual APACRS meeting, which is held in a different country each year, is one of the means of spreading knowledge throughout the region, Dr. Barrett said. Next year’s meeting, scheduled to be held in Singapore, will be in conjunction with the Asia Pacific Academy of Ophthalmology meeting, he said.
Sutureless manual procedure
A sutureless, large-incision manual extraction procedure may be the best technique for cataract surgery in rural China, according to Prof. Dennis S.C. Lam, FRCOphth, of Hong Kong, who spoke here at the meeting.
Citing barriers such as the cost of delivering care and the lack of infrastructure in rural villages in China, Prof. Lam said there is a need to develop a low-cost, easily managed, reliable cataract surgical procedure that can be taught easily to local surgeons.
“We need to be able to provide quality cataract surgery in an affordable manner close to where people live,” Prof. Lam said.
“Phaco is too expensive, while small-incision procedures require a highly skilled surgeon that makes the procedure difficult to teach,” he said. “An ideal surgery would be sutureless, safe and effective with little astigmatism, low cost and would be easy to teach and learn.”
He said he believes that sutureless large-incision manual cataract extraction (SLIMCE), a technique he developed, may be the solution to this problem.
Prof. Lam said conventional wisdom has it that a large incision will induce astigmatism. To date, he said, he has not found that to be true in his results with the SLIMCE technique.
|
For the procedure Dr. Lam uses either peribulbar or retrobulbar anesthesia. No facial block is needed. He uses a temporal approach.
To perform the technique Prof. Lam said he fixates the globe with 0.12-mm forceps. He then makes an 8-mm incision at 200 µm depth and then uses a crescent knife to create a scleral tunnel.
“It’s about 2 mm to the clear cornea, so the tunnel is about 4 mm in length,” he said. “For those with experience creating a small tunnel, it shouldn’t be too difficult to create a large tunnel.”
He instills two drops of trypan blue dye under air to facilitate capsulorrhexis in hard nuclei.
“You can use a cystotome in vitro or use forceps to complete your capsulorrhexis,” he said.
It is important to create a large, 6-mm capsulorrhexis, Prof. Lam said: “Otherwise you may have problems getting the nucleus into the anterior chamber.”
To move the lens from the capsular bag into the anterior chamber, Dr. Lam uses two Sinskey hooks, one placed at the far end of the lens from the incision and the other placed at the near end. While pulling toward the incision from the far end, Prof. Lam also applies downward pressure on the near hook to “tumble” or invert the lens into the anterior chamber.
“We have tried many methods for removing the lens from the bag, and we find this method results in the least zonular stress,” Prof. Lam noted.
To remove the lens through the scleral tunnel, Prof. Lam inserts an anterior chamber maintainer to apply pressure and also applies pressure to the opposite end of the sclera with Utrata forceps to push the lens through the tunnel.
“The important part here is that if you do the tunnel right, the nucleus will not actually hit the endothelium, and by having an anterior chamber maintainer increasing the pressure the nucleus will be pushed toward the tunnel,” Prof. Lam said. “Then you press on the sclera so that the flow of the nucleus will be toward the scleral tunnel.”
He removes the viscoelastic and checks the wound and the tunnel to ensure there are no nuclear fragments or any residual cortical matter.
“At the end of the day we can use cautery to close the conjunctiva without any sutures,” he said.
In Hong Kong, Prof. Lam said, he performed this procedure on 100 consecutive eyes and found the endothelial cell loss to be less than 5%.
“We only lose around 100 to 200 cells on average,” Prof. Lam said.
‘Sayonara, bimanual’
A technique for cataract surgery that allows IOL insertion through an incision of less than 2 mm following coaxial phacoemulsification will lead ophthalmologists to say “Sayonara, bimanual,” according to Takayuki Akahoshi, MD.
He described his novel technique at an Alcon-sponsored satellite symposium held during the APACRS meeting.
Dr. Akahoshi said his “Sayonara, bimanual” technique requires none of the “expensive and unfamiliar equipment” needed for bimanual microincision cataract surgery (MICS).
“We can use conventional instruments and techniques, and it is not necessary to use expensive capsulorrhexis forceps or unfamiliar irrigating choppers” such as those needed for bimanual MICS, Dr. Akahoshi said.
The technique is performed with a flared phaco tip with a small-diameter sleeve on the Alcon Infiniti phacoemulsifier, he said.
In eyes with dense cataracts, Dr. Akahoshi said, he supports the nucleus with a device called a nucleus sustainer. Using the ASICO Universal Prechopper, he divides the nucleus into small pieces to allow easy emulsification.
Following cataract removal, Dr. Akahoshi inserts a 6-mm Alcon AcrySof IOL through the unenlarged sub-2-mm phaco incision with a standard cartridge injector and inserts the IOL using what he called a counter-traction technique.
Loading the C-cartridge, Dr. Akahoshi places both haptics on the optic and places the lens in the cartridge at a downward angle. After affixing the cartridge to the injector hand piece, he stabilizes the eye with the nucleus sustainer, which also serves to provide a counterforce to the injection. The cartridge will not fit through the ultrasmall incision, so Dr. Akahoshi places it just at the edge of the incision and pushes the plunger to inject the lens into the eye through the unenlarged sub-2-mm incision.
A key to the technique, Dr. Akahoshi said, is the elbow joint between the optic and the haptic on the AcrySof lens. When he pushes the lens through the incision, “the elbow can easily open the incision and open into the anterior chamber,” he said.
Dr. Akahoshi said any one-piece AcrySof lens works using this technique because of this elbow design.
Other key aspects to performing the procedure successfully, Dr. Akahoshi said, are using the proper phaco settings, maintaining a firm anterior chamber with viscoelastic, using counterforce properly with the nuclear sustainer, continuing the insertion of the lens once insertion has begun, and using a new cartridge with every insertion.
“With these techniques we now can perform sub-2-mm incision coaxial surgery successfully,” Dr. Akahoshi concluded.
I&A tip for capsulorrhexis
An I&A tip can be used to perform capsulorrhexis in bimanual phaco, according to Pannet Pangputhipong, MD, who devised the technique.
“I&A rhexis is an inexpensive and safe alternative to more expensive capsulorrhexis forceps or using a cystotome,” Dr. Pannet said.
He noted that micro-forceps for performing capsulorrhexis through a microincision are expensive. Using a cystotome is a less costly alternative, but it is slower than the I&A rhexis technique, he said.
The I&A rhexis procedure can be performed with or without viscoelastic, Dr. Pannet said.
When using the I&A tip for capsulorrhexis, the surgeon must keep the vacuum level low, but high enough to grab and hold the capsular flap, Dr. Pannet said. He keeps the vacuum setting between 100 mm Hg and 150 mm Hg.
He cautioned that there is a lengthy learning curve for the procedure, but he stressed that the procedure can be worth learning for its safety and for avoiding the expense of micro-forceps.
He said he first developed the procedure while performing standard coaxial cataract surgery and then adopted it for his bimanual microincision cataract surgery procedure. He recommended that other surgeons follow this approach to the learning process for the technique.
Quality of vision measurement
A new device measures visual acuity, contrast sensitivity, accommodation and modulation transfer function all in one short screening, according to a researcher familiar with the device.
“You can have an objective comparison to know the eye’s visual performance, and it is based on the double-pass system, which is better than just measuring aberrometry,” said Prof. Bo T. Philipson, MD.
Prof. Philipson said the Objective Evaluation of Quality of Vision device, created by Pablo Artal, of Murcia, Spain, performs all the measurements in one easy screening that can be performed by a trained technician.
“It gives an objective image of what your patient sees,” Prof. Philipson said. “From there you can draw significant differences between different models of IOLs.”
For Your Information:
- David W. Mullin is Managing Editor of OSN Europe/Asia-Pacific Edition.