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World Ophthalmology Congress opening ceremony reflects pride of Hong Kong
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HONG KONG — Remarks delivered during the opening ceremony of the World Ophthalmology Congress held here conveyed a sense of pride with Hong Kong serving as host, but there was also a tinge of sadness over recent tragedies that have beset the Chinese people.
After leaders of dozens of international societies filed in front of several thousand audience members in the ceremonial processional, Dennis S.C. Lam, MD, FRCOphth, president and organizing chairman of the WOC, told attendees in his opening speech that he “stands before you with mixed emotion.”
“As a global citizen and as a Chinese, my heart goes to the people afflicted with pain in China,” he said, referring to the snow storms and earthquakes in recent months that left death and destruction in their wake. He asked the audience to observe a minute of silence.
Striking a lighter tone, Prof. Lam congratulated the organizers of the Congress for its success, calling the WOC the “Olympics of ophthalmology.”
Just as Beijing lost to Sydney in 1994 in its bid to host the 2000 Olympic Games, Hong Kong also lost to Sydney in its bid to host the WOC in 2002, he said.
But this year, Hong Kong hosted the WOC, and Beijing will host the summer Olympics in August. “There is a saying that failure is the mother of success, which is coincidentally applicable to … both Olympics,” he said.
Prof. Lam’s comments were followed by those of John Tsang Chun-wah, JP, acting chief executive of the Hong Kong Special Administrative Region, who discussed how the WOC started in 1857 with a meeting of 150 ophthalmologists in Brussels.
 From left to right, Bruce E. Spivey, MD, MS, MEd; John Tsang Chun-Wah, JP; Dennis S.C. Lam, MD, FRCOphth; and Yasuo Tano, MD, stand with their hands on the ceremonial ‘pearl’ to commence the 31st World Ophthalmology Congress in Hong Kong. | ||
“At that time, Hong Kong was little more than a fishing village on the China coast. How things have changed,” Mr. Tsang said. “This year, the Congress brings together some 10,000 eye specialists from around the world, including 3,000 from mainland China. And Hong Kong has evolved from a little fishing village into a modern, international business and financial center that is the event capital of Asia.”
Bruce E. Spivey, MD, MS, MEd, president of the International Council of Ophthalmology, and Yasuo Tano, MD, president of the Asia-Pacific Academy of Ophthalmology, also offered welcoming remarks. Dr. Spivey noted that the Olympic slogan of “One World, One Dream” is also applicable to the WOC.
“I challenge every one of us to commit [ourselves] … to the eradication of blindness, particularly in developing countries,” he said.
The speeches were followed by an award presentation ceremony and performances in Chinese martial arts, traditional “face changing” and a fluorescent dragon dance.
These items appeared originally as daily coverage from the meeting on OSNSuperSite.com. Look for more in-depth coverage of these and other topics in upcoming issues of Ocular Surgery News.
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Refractive Surgery
Experts debate wavefront and topographic approaches to aberrated corneas
Topography- and wavefront-guided approaches to repairing corneal refractive complications each have advantages, yet neither approach provides a complete picture to shape the best treatment algorithm, according to two experts who debated the subject.
Arthur Cheng, MD, and OSN Refractive Surgery Section Member Marguerite B. McDonald, MD, discussed the technologies during Cataract and Refractive Surgery Subspecialty Day. They agreed that the optimal approach to surgically induced aberrations uses information from both the cornea as well as from other intraocular structures.
Dr. Cheng argued that topography-guided treatment is generally a better approach to treating patients with irregular corneas caused by previous refractive surgery.
“The golden rule of medicine is to treat the underlying cause,” Dr. Cheng said. “If you look at the sequence of events… [patients] started with well-balanced optics. Patients may have myopia or hyperopia … but with spectacles or contact lenses, they are generally happy with their quality of vision, and the lower-order aberrations are more than the higher-order aberrations.”
Higher-order aberrations increase significantly once flap or ablation complications occur. Because these aberrations arise from the cornea, it is the cornea that should be measured to determine how to re-treat these patients. Also, highly aberrated corneas might be scarred, giving inconsistent and unreliable results, Dr. Cheng said.
“In many of these patients, we cannot even capture a wavefront image,” he said.
Wavefront topography is further limited by a relatively large deviation of the projected ray of light from the reference position in aberrated eyes. Topography-guided ablation not only overcomes these limitations but also provides excellent corneal wavefront data, he said.
Dr. Cheng said topography-guided ablation provides no information about intraocular structure, and ideally, it would be combined with wavefront technology.
“Both wavefront-guided and topography-guided treatments are complementary,” he said.
Dr. McDonald agreed that the best approach is a combined approach. But she said current technology has just begun to address this need.
“Too often our most desperate patients are ‘uncapturable’ with current technology. They need evaluation of the optics of the entire eye, not just the cornea,” she said.
The ideal device for highly aberrated eyes, she said, would offer high-resolution images, high dynamic range, a wide field of view, auto-centration and Fourier-generated ablation patterns. It would also combine the utility of an aberrometer, autorefractor, pupillometer, keratometer and a topographer.
A device matching these criteria, the iDesign aberrometer, has been developed by Advanced Medical Optics, Dr. McDonald said.
The device provides a higher resolution than most wavefront-guided aberrometers, addressing the “one drawback to wavefront [technology],” as it exists today, she said.
Overall, Dr. McDonald said currently available wavefront technology can capture a wider range of highly aberrated eyes than ever before.
“Only a small percentage is not capturable with new technology and is therefore in need of topography-driven ablations,” she said. “Wavefront-driven ablation provides accurate correction of the eye’s entire optical vision. This is especially important for treating our highly aberrated patients who accessed refractive technology many years ago and now have lenticular changes as well as corneal aberrations.”
Assessment of femtosecond complications has clinical value
Femtosecond laser technology has firmly taken root as an important tool in refractive surgery. However, an assessment of potential complications can hold valuable clinical lessons, according to one surgeon.
 Roy S. Chuck |
Roy S. Chuck, MD, PhD, presented an overview of his personal complication profile from his first 1,000 cases using the IntraLase femtosecond laser (Advanced Medical Optics).
Dr. Chuck has been using IntraLase for about 5 years, and “it now comprises 90% of my refractive surgery practice,” he said.
The first complication Dr. Chuck outlined was an incomplete flap, which he said occurred in four cases of the 1,000-case series. These complications were resolved fairly easily by passing the IntraLase again, using the same patient interface. If the flap is lifted and adhesion is minimal, he suggested attempting blunt instrument lysis. If there is significant adhesion, he recommended replacing the flap and performing PRK at a later date.
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He described having a few cases of decentered or small flaps, yet none were decentered or small enough to abort the procedure. His solution is to make a slightly larger flap of about 9 mm to 9.5 mm because it is easier to accept a slight decentration than to re-center a smaller one, he said.
Dr. Chuck had two cases of slipped flaps, as well as two cases of partially slipped flaps induced by trauma. He said neither of the traumatically induced cases had to be re-treated.
The highest complication rate was with diffuse lamellar keratitis, which occurred in 20 to 30 cases. All but one case was mild, and most cases were associated with power adjustments and upgrading to higher- frequency pulse engines.
The most interesting complication, Dr. Chuck said, was that of gas bubbles in the anterior chamber. There were two cases in the 1,000-case series, but since then, there have been eight to 10 more cases.
He said these are of unknown etiology and are not related to flap perforation. Once it is determined that there is no perforation, the excimer laser procedure may proceed. But surgeons might experience some gas bubble interference with iris registration and pupil tracking.
Dr. Chuck said because about 20% to 30% of all flaps in the United States are made with IntraLase, “it’s a technology that it appears is here to stay,” so surgeons should be aware of potential complications and how to address them.
Femtosecond laser-created flap complications rare, easily treatable
Femtosecond laser-created flap complications are rare in LASIK procedures, but the complications that occur are often easily dealt with, a surgeon said.
 John S. Chang |
John S. Chang, MD, of Hong Kong, described his own experiences with femtosecond laser complications and the steps he took to remedy those problems.
“Surgery with femtosecond laser-created thin flaps is slightly more difficult, and a new set of potential complications can occur but are easily dealt with,” Dr. Chang said. He described one case in which he had an avulsed flap after mistaking a nasal hinge for a superior hinge.
“Fortunately, this was discovered early enough, and the dissection was stopped at the distal edge,” he said. “So a new pseudo hinge was created.”
In cases in which the flap is moved, Dr. Chang said the flap should be repositioned as soon as possible, and a bandage lens can be used to promote healing.
“Remove the epithelial cells from the stromal bed edge to avoid epithelial ingrowth,” he noted.
Vertical gas breakthrough can also occur, and in these cases, the breakthrough can prevent further bubbles from forming, and the flap cannot be created, Dr. Chang said.
“If the vertical gas bubbles do not go through the epithelium, surgery can be completed, but if they do go through, the bubble will be large and the surgery cannot go on,” he said.
Dr. Chang said he has encountered two cases with the large bubble vertical gas breakthrough. In one case, he re-cut with the femtosecond laser at the same depth from another direction. In the other, he re-cut the flap with a mechanical microkeratome. In both cases, he successfully lifted the flap and continued the laser procedure without further complications.
Cases of epithelial ingrowth should be treated early because of the higher risk of flap necrosis, he said.
“Be sure to remove the epithelial cells from the stromal bed as well as underneath the flap,” he said. He uses 0.02% alcohol to kill the epithelial cells.
In cases of diffuse lamellar keratitis, Dr. Chang advised aggressive early treatment to avoid flap necrosis and perforation. In cases in which the diffuse lamellar keratitis is grade 2 or worse, the eyes are given a washout in the operating room and then treated with topical and systemic steroids.
He said all complications should be dealt with on the same day of surgery.
Toric phakic implant improves vision after cross-linking therapy for keratoconus
Toric ICL implantation 1 year after corneal collagen cross-linking for patients with keratoconus improves uncorrected visual acuity, according to a study.
 Alaa El Danasoury |
Alaa El Danasoury, MD, FRCS, chief of refractive surgery at Maghrabi Eye Hospital in Saudi Arabia, presented results from a study on toric ICL (STAAR Surgical) implantation in 32 eyes of 22 keratoconus patients 1 year after cross-linking therapy. Dr. El Danasoury said a stable cornea is not enough to satisfy keratoconus patients.
“At about 1 year after cross-linking therapy, the keratoconus patients come in and say, ‘OK, doctor, I came in originally to improve my vision. Now you are telling me my cornea is stable, and for that, I thank you very much, but I still cannot see.’ So we offer them a toric ICL,” he said.
Dr. El Danasoury said he waits 1 year to ensure corneal stability before implanting the ICL.
“We conducted this study 2 years ago to assess the safety, the efficacy, the stability of toric intraocular lens to correct the compound myopic astigmatism normally associated with keratoconus post-corneal cross-linking,” he said.
Patients ranged in age from 19 to 36 years, with a mean age of 24.1 years. Fifty-eight percent were men. Baseline mean spherical equivalent was –8.56 D ± 4.38 D. Mean baseline cylinder measured –3.44 D ± 1.68 D. A total of 30 eyes completed 1-year examination.
Dr. El Danasoury performed ICL implantation through a 3-mm clear corneal incision under topical anesthesia and also performed surgical iridectomies.
“In these cases, the technique of implantation of the ICL is not much different than that in a virgin eye,” he said.
According to Dr. El Danasoury, at 1 day postop, 94% of uncorrected eyes could see 20/40, 81% could see 20/30 or better, and 56% could see 20/20 or better. This compares with preop best corrected visual acuity of 100% at 20/40 or better, 84% at 20/30 and 44% at 20/20 or better.
At 12 month follow-up, 30 eyes had a mean cylinder of –0.26 D at 144.4 inches.
Understanding choices in bioptics can enhance outcomes
Carefully selected IOLs in conjunction with femtosecond-flap creation and wavefront-guided LASIK can assist surgeons in their quest to provide spectacle independence for patients, according to a surgeon.
Michael C. Knorz, MD, explained his approach to bioptics using IntraLase and a variety of phakic and multifocal IOLs.
“Phakic IOLs or diffractive multifocal IOLs can be combined with IntraLase flap creation and … wavefront-driven ablations to achieve perfect vision,” he said.
His approach consists of offering an IOL and subsequent refractive surgery to correct residual refractive error as a package so patients know what to expect, Dr. Knorz said.
Yet he cautioned that “the multifocal and phakic IOLs work only if a patient is ametropic” because the goal is for the patient to achieve spectacle independence.
Dr. Knorz said he has two main approaches to bioptics. The first is to perform customized LASIK with the VISX Star S4 excimer laser (AMO) about 3 months after IOL implantation if there is unexpected refractive error.
“This is if there is [pre-existing] corneal astigmatism less than 2 D because I feel I can manage the astigmatism with my incision during the surgery,” he said.
The second option is geared for patients with pre-existing astigmatism greater than 2 D. Dr. Knorz said he does not expect to be able to eliminate that level of astigmatism in the course of the IOL implantation and anticipates having to do another refractive procedure later.
In these cases, he creates an IntraLase flap before IOL implantation but does not lift it. He performs custom LASIK 3 to 4 months later.
He opts for custom LASIK because it “provides a perfect match of the measured and treated area, and this gives you better astigmatism correction.”
“If you have just 10° of error at the axis, that means 30% under-correction. In these patients, it’s important that we align treatment and measurement areas, and this is only possible with custom LASIK,” Dr. Knorz said.
Custom LASIK compensates for cyclotorsion as well as changes in the pupil center position, he said.
One caveat Dr. Knorz offered is that wavefront-guided LASIK works with diffractive IOLs such as the Tecnis (AMO) or ReSTOR (Alcon) but not with a refractive IOL such as the ReZoom (AMO).
Surgeons must approach refractive lens exchange with the knowledge to explain risks
Refractive lens exchange can provide an array of visual benefits; however, surgeons must arm themselves with knowledge to convey the potential risks to patients who are candidates for the procedure, a speaker said.
 Emanuel S. Rosen |
Emanuel S. Rosen, MD, FRCOphth, said that he feels the benefits of this procedure outweigh the risks, but the risks cannot be underestimated.
“The positive, life-changing benefits are immense for patients who suffer from high ametropia. The relief from high spectacle correction or contact lens intolerance is really great for them,” Dr. Rosen said. “Yet I approach this from the point of view of the comprehension of risks.”
The best candidates for refractive lens exchange are patients with hyperopia who are ages 55 years or older, he said. Younger myopes have a greater axial length and will experience greater retinal stretching. Retinal detachment is one of the top concerns for myopic patients, although Dr. Rosen emphasized that outcomes from correction of retinal detachment are good.
The incidence of pseudophakic rhegmatogenous retinal detachment in myopic eyes varies from 0% to 8% in the literature, and the mean cumulative incidence is 1.71% (one out of 58 eyes), Dr. Rosen said. Sometimes the detachment can occur 21 years or more after surgery, so this risk factor is something surgeons must explain thoroughly.
Lens extraction also increases the risk of posterior vitreous detachment in older myopic patients, he said, although the risk is lower in patients who have had a prior posterior vitreous detachment.
Surgeons must also emphasize that the procedure is permanent, unlike phakic lens implantation.
Options for replacement of the natural lens in these eyes include monofocal (with or without induced monovision), bifocal or accommodative IOLs.
An accommodative IOL utilizes several aspects of pseudoaccommodation, “trying to give patients the best of all worlds,” Dr. Rosen said.
Hyperopic eyes, in which LASIK is often not the best option, can also benefit from refractive lens exchange but with fewer risk factors.
“Hyperopic eyes, in contrast to myopic eyes, show low incidence of retinal detachment, and in our own series of 1,000 eyes, we’ve only had one retinal detachment,” he said, noting that long-term research of this aspect is needed.
Combating corneal ectasia demands that surgeons expand their notions about the disease
Surgeons have more advanced and targeted tools at their disposal to precisely screen patients for corneal ectasia, a speaker said.
Bradley J. Randleman, MD, discussed known and presumed risk factors of the disease, as well as screening strategies.
Dr. Randleman and colleagues at Emory University in Atlanta created a risk assessment model for ectasia, which assigns a point value to a variety of parameters including age, sex, manifest refraction spherical equivalent, preoperative corneal thickness, predicted residual stromal bed and topographic patterns.
They sought to better identify patients who are at high risk of ectasia but might not have presumed risk factors.
“Our goal is to identify 100% of [high-risk] patients. I don’t [know] that we will ever achieve that, but it is certainly our goal,” he said.
The estimated incidence of corneal ectasia is about one in 2,500, but Dr. Randleman said this number might not be accurate.
“This could be an overestimate because of current exclusion criteria, and we certainly hope this is the case. It also could be an underestimate because of the limited follow-up and underreporting because we know ectasia can be a later onset complication,” Dr. Randleman said.
The primary risk factors for postoperative ectasia include topographic abnormalities and low residual stromal bed thickness, although Dr. Randleman warned that the conventional wisdom declaring 250 µm as a cutoff value should be eliminated.
 A performance of “face changing,” or Bian Lian, an ancient Chinese dramatic art, was presented at the conclusion of the WOC Opening Ceremony. Image: Irvine S, Wide Eye Productions Ltd. | ||
“We should wash this number out of our heads as being a cutoff value because we know that a number of cases developed ectasia with a residual stromal bed greater than that, and many normal patients have been lower than that,” he said. “It does not have a significant value as a safety cutoff or a risk factor in itself.”
Other warning signs include patient age — because corneal tensile strength increases with age — and extreme myopia.
Overall, a comprehensive weighted scale is preferable to looking at individual cutoff values. However, surgeons should be aware that postoperative ectasia can still develop in patients without risk factors or other known intraoperative incidents. This could be because of unidentified ectatic disorders at the time of surgery, patient-related factors such as eye rubbing or other factors that have yet to be determined, Dr. Randleman said.
He encouraged surgeons to carefully screen all patients, eliminate microkeratomes that produce unpredictable flaps and discourage eye rubbing in patients postoperatively. He also urged them to search for additional risk factors and to utilize resources such as ectasiaregistry.com to enhance the body of knowledge about the disease.
Removal of one intracorneal ring segment could improve visual acuity in myopic patients
The removal of one intracorneal ring segment in myopic keratoconic patients who have had poor results with double ring implantation can improve visual outcomes, a surgeon said.
Brian S. Boxer Wachler, MD, described outcomes in 13 eyes of 10 myopic patients who underwent explantation of their upper Intacs segment (Addition Technology). The patients’ average visual acuity before the upper segment was removed was 20/50. After the segment was removed, the average visual acuity improved to 20/30, Dr. Boxer Wachler said.
Improvement in visual acuity was seen in all 13 eyes. Seven eyes (54%) gained one line, four eyes (32%) gained two lines, one eye (7%) gained three lines, and one eye (7%) gained four lines.
This apparent improvement in visual acuity is “counterintuitive and hard to explain,” Dr. Boxer Wachler said. However, corneal topography helps demonstrate why two segments will not bring about the desired effect in the flattest area of the cornea.
“When you place two segments, Intacs will always flatten. That is what they do — that’s their goal in life,” he said. “But why do you want to make a flat area even flatter? You really don’t. If anything, you want to make the [flatter zone] actually steeper.”
Dr. Boxer Wachler said explantation of the upper segment is not technically difficult to accomplish.
“You can even just make a little cut down over the tip of Intacs, and you don’t have to go over the incision. You don’t have to worry about going back over the original channel,” he said.
Further, removal of the upper segment is as beneficial as if only one segment had been implanted at the outset, in that it will allow steepening to occur in areas that are being flattened by the segment.
Dr. Boxer Wachler also said surgeons can “make huge improvements in astigmatism” by placing a few conductive keratoplasty (Refractec) spots on the cornea.
“If you see someone with double segments, look at the topography, look at the location of the segments and see if it would make sense to explant the ones from the flat area of the cornea,” he said.
Outcomes less predictable in cataract patients with previous refractive surgery
Surgeons should temper the expectations of previous refractive surgery patients who require cataract surgery, a surgeon said.
“Counseling is key to managing post-LASIK cataract patients because outcomes are less predictable. You need to moderate their expectations,” Han-Bor Fam, MD, said. “The more you dampen their expectations, the more happy they will be. You have to tell them that they may require more procedures after the surgery if they want to have spectacle independence.”
Dr. Fam said preoperative measurements in LASIK-treated patients who need cataract surgery are complicated and require more caution on the part of the surgeon.
“These patients have high expectations of being spectacle independent and having good vision. After all, this is the underlying reason for them to have LASIK,” he said. “Target refraction is not very predictable so … in my case, I like to dampen the patient’s expectations. I usually tell them that they will probably have to rely on glasses, even though if they don’t, that is a bonus.”
If patients suggest contact lenses, Dr. Fam said he explains that their corneal curvature has changed, and they may not be able to wear contact lenses or may require special lenses.
He said patients should be aware of the possibility of additional dry eye and glare or halo complications as well as the need for enhancements if they wish to be spectacle independent.
“I will usually explain to the patient that they’ll probably need enhancements. That depends on how much tissue they have left and what are the post-cataract surprises,” Dr. Fam said. “With all of this, there’s a cost factor involved, which I will explain to them as well.”
Cataract Surgery
SLIMCE results safe; skills transferable in rural setting
Sutureless large-incision manual cataract surgery has been shown to be a practical, safe and transferable skill in both urban and rural settings, according to a speaker.
Prof. Lam described the technique and results that it has produced in an experimental rural eye unit during Cataract and Refractive Surgery Subspecialty Day.
According to Prof. Lam, sutureless large-incision manual cataract surgery (SLIMCE) can play an important role in bringing safe and affordable surgery to more patients, particularly those in rural settings who would not otherwise be able to afford cataract surgery.
“I think SLIMCE procedures can be performed safely in rural settings, and skill transfer is possible with a short learning curve, even to inexperienced surgeons,” he said.
Prof. Lam discussed prospective study results of 313 patients who underwent cataract extraction by two local surgeons in rural Sanrao, China. Of these, 85.2% had a preoperative visual acuity of 6/60 or worse. The postoperative uncorrected visual acuity was better than 6/18 in 86.3% of eyes, and the postoperative best corrected visual acuity was better than 6/18 in 97.1% of eyes.
The two surgeons who performed all of the cataract extractions were trained to perform SLIMCE independently in 5 months. Since the Sanrao center was opened in December 2004, the same two surgeons have done more than 3,000 cataract surgeries using this technique, averaging about 100 cases per month, Prof. Lam said.
Of the Chinese population, more than 800 million people live in rural villages, he said. The ability to train rural surgeons to perform a technique that is safe and transferable is essential to providing much needed services to this underserved population.
“But before we do that in the village, we need procedures that are simple, safe, effective, easy to learn and easy to transfer the skills to local doctors,” Prof. Lam said.
He and colleagues have also studied the endophthalmitis rate among those patients who have undergone SLIMCE in the rural hospital.
There have been three reported cases among 3,000 patients since December 2004. The low infection rate can be attributed to the fact that the procedure is done through the sclera and not clear cornea, and the wound is well-covered by the conjunctiva, according to Prof. Lam.
Overall, he said, the results from this experimental model “confirmed the effectiveness of skill transfer in rural areas with superior outcomes to most studies in rural Asia.”
Bimanual MICS, microphaco incisions comparable
An analysis of the quality of incisions in bimanual microincision surgery and microincision coaxial phaco showed equivalent incision quality in both procedures, according to a speaker.
Jorge L. Alió, MD, PhD, of the Vissum Institute in Alicante, Spain, presented the results of a study using the Visante OCT (Carl Zeiss Meditec) corneal incision analysis model on 25 eyes of 16 patients who underwent bimanual microincision cataract surgery (MICS) and 25 eyes of 18 patients who underwent microphaco coaxial phacoemulsification. Prof. Alió performed all surgeries, and postoperative analysis was performed by an independent observer.
 At the ICO Presidents’ Dinner at the WOC, famed artist Mrs. Chiu Ng Yuet Lau was on hand, not only to show her skill and artistry in creating one of her nature paintings, but also to donate a painting for auction to raise money for the ICO Foundation. The bidding started at $3,000 but eventually was won with a winning bid of $11,000 by Ms. Nellie Fong, who is the founder of the Hong Kong Lifeline Express Foundation. She is also the chairwoman of PricewaterhouseCoopers China operations. Bruce E. Spivey, MD, (left), artist Mrs. Chiu Ng Yuet Lau, her son Philip Chiu, MD, and Dennis SC Lam, MD, FRCOphth, stand with Mrs. Chiu’s painting. Image: Mullin DW, OSN |
The main difference between the two surgeries is that MICS employs a sleeveless or unprotected phaco tip, whereas microphaco uses a sleeved or protected phaco tip, he said, noting that the bare titanium tip in MICS is potentially harmful to the incision wound.
Prof. Alió said he performs MICS with a 1.2-mm incision and microphaco with a 2.2-mm incision.
Incisional-angle geometry assessed using Visante OCT showed “excellent quality in both groups with no statistically significant differences,” he said.
The only notable difference observed in the study between MICS and microphaco was less corneal edema in MICS cases at postop day 1.
“MICS showed less corneal thickness in an area of 3 mm and 5 mm of the cornea but only on day 1,” Prof. Alió said.
All other OCT outcome parameters, including topographic corneal and ocular aberrometric variables, did not differ significantly, he said.
“At month 1, all of the incisions in both groups were perfect, without any gaping or endothelial bulge or Descemet’s detachment,” he said.
“MICS is associated with less corneal edema in the short-term outcomes and less induction of corneal aberrations in the long-term results,” Prof. Alió said.
Because incision quality has a tremendous influence on the overall outcome of cataract surgery, he said he found Visante OCT corneal incision analysis model useful in assessing the quality of the incisions in cataract surgery. He also noted that smaller incisions minimize trauma to the eye and create a better surgery.
Posterior-assisted levitation best solution for dropped nuclei, surgeon says
Posterior-assisted levitation is the preferred method to retrieve a nucleus or dropped posterior chamber IOL that has fallen into the posterior chamber during phacoemulsification, according to a surgeon.
Soon-Phaik Chee, MD, of the Singapore National Eye Center, described her method and gave pearls for posterior-assisted levitation, or PAL.
In her method, originally described by Charles D. Kelman, MD, in 1996, Dr. Chee first fills the anterior chamber with dispersive viscoelastic. Then she inserts a 1-inch 25-gauge needle through a 3.5-mm incision in the limbus and guides the needle behind the nucleus or IOL. The needle is carefully inserted behind the nucleus. She does not inject any more viscoelastic until the nucleus is guided back into the anterior chamber and retrieved.
“The procedure must be performed as soon as possible, and the nucleus fragment or [posterior chamber] IOL must be identifiable through a surgical microscope,” Dr. Chee said.
“You must be careful when putting the needle in, and observe in what direction the lens has descended so that the needle can best support it,” she said.
“Move the eye in the direction of the fragment using forceps, and indent the sclera with a cotton tip,” Dr. Chee said.
She introduces a Sinskey hook to position the fragment in the anterior chamber “OVD trap” while the needle is being removed, she said.
Dr. Chee offered surgical pearls for this technique, including bending the distal shaft of the needle; avoiding injecting viscoelastic into the vitreous cavity; delaying vitrectomy until after removal of the nucleus fragment or posterior chamber IOL; attempting PAL only once; and seeking a retinal consult postoperatively to check for any retinal tears that may have occurred.
PAL is contraindicated if the surgeon cannot see the fragment, if the nucleus or IOL is touching the retina, or if a single attempt has failed.
Dr. Chee reviewed cases at the Singapore National Eye Center between 1996 and 2006. She found two out of 14 cases had a complication. One case had a macula-off pseudophakic inferior retinal detachment at 20 months. The other was minor and resolved.
Artificial posterior chamber saves capsular rupture cases during phaco
In cases in which there is a loss of barrier between the anterior chamber and vitreous, an artificial posterior chamber can help maintain a safe cataract surgery, according to a speaker.
Kenneth Lu, MD, described his artificial posterior chamber technique as a means to help avoid bigger problems in cases in which there is a loss of barrier between the anterior chamber and the vitreous.
In cases of posterior chamber rupture during phaco, the artificial posterior chamber can help surgeons avoid more difficult and potentially harmful previous solutions such as enlargement of the incision and conversion to an extracapsular technique, which can lead to a difficult closure, postoperative astigmatism or cystoid macular edema, Dr. Lu said. Continuing phaco after posterior chamber rupture risks pulling vitreous into the anterior chamber, causing retinal traction or dropping the nucleus.
For these cases, Dr. Lu has reshaped a lens guide into a head-and-shoulder style configuration that is foldable. His goal is to maintain a small incision site while still being able to create a temporary barrier between the anterior chamber and vitreous. “The head stays inside the eye and acts as a barrier, and the shoulder allows the lens guide to stay in place without advancing further into the eye,” Dr. Lu said. “Basically, you just fold it like an IOL and then insert it underneath the cataract. You will need a lot of viscoelastic in the eye in this situation. The temporary barrier allows you to continue phaco as usual.”
At that point, Dr. Lu pulls the lens guide from the eye without the need of refolding because of the slope of the design.
“This method allows for successful completion of phaco after rupture of the posterior capsule when there are still some fragments left,” he said.
Dr. Lu added that it is important to identify the rupture quickly before the lens drops for this method to work.
Surgeon prefers temporal clear corneal incisions
With a study showing no significant difference in astigmatism between temporal or on-axis incisions in cataract surgery, one speaker recommended temporal incisions based on ease and convenience of the technique.
Edmondo Borosio, MD, conducted a pilot study to determine the difference in surgically induced astigmatism and postoperative visual acuity from temporal vs. on-axis clear corneal incisions in cataract surgery.
The randomized, controlled clinical trial was conducted on 61 eyes of 50 patients, Dr. Borosio said. One surgeon performed all surgeries with a 3.2-mm clear corneal incision and implanted an Akreos Adapt IOL (Bausch & Lomb) in all eyes. The incision meridians were marked at the slit lamp before the patients were given anesthesia to avoid cyclotorsion between sitting and supine positions.
Topography revealed preoperative astigmatism of 1.22 ± 0.65 D in the on-axis group and 1.01 ± 0.49 D in the temporal group, he said, so the preop astigmatism between the two groups was similar (P > .05).
“There was no significant difference in surgically induced astigmatism at 3 weeks,” Dr. Borosio said.
The difference was 0.50 D at 87° in the temporal incision group and 0.65 D at 88° in the on-axis group ( P > .05).
“Astigmatism meridian shifts occurred more frequently in the on-axis than temporal group,” he said.
“For corneal astigmatism of less than 2.6 D, the two incisions performed equally in terms of surgically induced astigmatism, final best corrected visual acuity and defocus,” Dr. Borosio said. “Operating on-axis can be technically more challenging for right-handed surgeons operating on right eyes with corneas steeper superonasally. Temporal incisions are always easy to perform independent of dexterity.
“The bottom line is that you may be used to doing it from the top, but doing it from the side is actually more convenient and less challenging,” he said.
Manual small-incision techniques offer affordable, high-volume surgery
Manual small-incision cataract surgery is not only cost-effective, but it also allows high patient turnover with good visual results, a surgeon said.
The Aravind Eye Hospital treats eight to 10 cataract patients per hour with the technique. The higher patient volume allows more effective and safe cataract extraction procedures to be performed at the hospital on a daily basis, R.D. Ravindran, MS, DO, said.
Dr. Ravindran, who is joint director and chief medical officer of Aravind Eye Care System, presented results from the hospital’s experience with manual small-incision cataract surgery (SICS) and standard extracapsular cataract extraction.
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“SICS has emerged as an affordable alternative to instrumental phaco,” he said. “There’s nearly comparable results, as far as visual outcomes are concerned.”
At Aravind Eye Hospital this year, 53,475 patients paid for procedures, and 127,587 patients had their cataracts removed without a fee, he said.
Because both manual SICS and extracapsular cataract extraction are low-cost procedures, they are excellent choices for patients who cannot afford phacoemulsification, Dr. Ravindran said. For those who can afford phaco, the procedures are also sometimes a better choice than standard phaco.
“Even for patients who can pay, they are an ideal choice for advanced cataracts,” he said.
Results from a study by Parikshit Gogate, MS(Ophth), and colleagues that looked at 1,424 cases in a masked clinical trial showed that manual SICS has good visual results when compared with phaco, Dr. Ravindran said.
In the study, 372 out of 400 patients completed 6 weeks of follow-up. Patients were randomly assigned to either phaco or manual SICS. Of those patients, 68% in the phaco group and 61% of those in the manual SICS group had uncorrected visual acuity better than or equal to 6/18 at 1 week.
At 6 weeks follow-up, 81% of the phaco group and 71% of the manual SICS group had visual acuity better than or equal to 6/18, the study said.
Proper NSAID dosing regimen key to avoiding cystoid macular edema
With patient expectations at their highest levels, especially in clear lensectomy, proper nonsteroidal anti-inflammatory drug dosing is important in cataract surgery to avoid cystoid macular edema and the poor vision that can result, a surgeon said.
“Cystoid macular edema (CME) is the most frequent cause of visual decline following cataract surgery,” Joseph Colin, MD, of Hôpital Pellegrin, France, said. “CME development is due in part to a prostaglandin mediated breach of the blood-retinal barrier.”
According to Dr. Colin, even minimal amounts of CME can be especially damaging in refractive lens exchange because of its impact on vision with multifocal IOLs for patients who are expecting greatly improved vision.
Given properly, NSAIDs are able to limit prostaglandin formation, a major cause of postoperative CME, he said.
According to Dr. Colin, 80% of ophthalmologists in France currently use NSAIDs in cataract surgery. Although he views NSAIDs as an essential part of cataract surgery prophylaxis, they are also associated with several side effects, such as burning and irritation, superficial punctate keratitis and delayed wound healing. Corneal thinning and perforation from melts have also been reported, he said.
For patients not at risk of CME, Dr. Colin recommended a dosing regimen with Voltaren (diclofenac sodium ophthalmic solution 0.1%, Novartis) for 1 or 2 days preop and for 4 weeks after surgery. At-risk patients should receive dosing 1 week before surgery and for 8 weeks after.
“Proper NSAID prophylaxis is key to good surgical outcomes,” Dr. Colin said.
Pediatrics/Strabismus
Pediatric LASIK effective and stable over 10 years
LASIK in children was shown to be safe, effective and fairly stable over 10 years of follow-up in a long-term study.
 Osama Ibrahim |
“LASIK in children has the same efficacy, predictability and safety margin of others. Of course, your nomogram should be changed, depending on the condition of the other eye,” Osama Ibrahim, MD, said.
He has been performing surgical refractive procedures on pediatric patients since the introduction of refractive keratometry and has completed more than 800 LASIK cases to treat myopia, hyperopia and astigmatism.
In the study that he presented, Dr. Ibrahim showed safety, efficacy and stability data on 264 eyes of 264 patients who all had 10-year follow-up.
Parameters of success in this study were the ability to wear spectacles, best corrected visual acuity, the ability to resume or maintain occlusion therapy, and the stability of the procedure, he said. He told the audience that he only performs unilateral LASIK in children in hopes that they can resume their vision therapy, not in an effort to reach emmetropia.
Preoperatively, about one-third of the patients could see 20/100 or better, and the majority had a BCVA of less than 20/100.
“After LASIK, we were able to achieve 27% to 20/20 best corrected vision,” he said. “About half could see 20/40, and two-thirds were able to see 20/100.”
None of the group lost any BCVA, and the majority of patients gained lines. Two-thirds gained at least one line, and one-third of patients gained more than three lines of BCVA.
“Stability was interesting,” Dr. Ibrahim said. “There was reasonable stabilization up to 3 years, and then when they reached the age of puberty and normal growth, there was additional regression up to 10 years.”
Patients who had residual myopia continued to regress or have progressive myopia, whereas patients who received overcorrection had less regression or less progression as compared with the non-operated eye, he said.
“Remember that pediatric LASIK is not to get rid of glasses. It’s not to avoid the occlusion therapy, as most of the parents would love, and it’s not to stop the progression of myopia. And definitely, it’s not for bilateral patients. It’s only to help these poor patients to correct their anisometropia and help them to wear the spectacles,” he said.
Assisted conception results in more treatment-necessary cases of ROP
Infants born from assisted conception, such as in vitro fertilization, are at a higher risk of needing treatment for retinopathy of prematurity than those born of natural conception, a presenter said.
“Assisted reproductive technology is not without its risks. About 50% of those babies born are born through multiple births,” Grace Sun, MD, said. “Multiple births are associated with greater health risk for both mothers as well as infants. There’s an increased risk of [Caesarean] sections, of infant death and disability and, of course, of prematurity and low birth weight. … The singletons as well are born early and very light.
“Of course, when we hear prematurity and low birth weight, we always think of retinopathy of prematurity (ROP),” Dr. Sun said. “Our question was: ‘Is assisted conception associated with treatment-requiring ROP?’”
The retrospective study looked at 358 infants born and screened for ROP between June 2002 and August 2007. Of those infants, 135 were conceived via assisted conception.
The study showed a statistically significant relationship between assisted conception and ROP cases requiring treatment, she said.
Of infants with very low birth weight of less than 750 g, 11.54% of natural conceptions required ROP treatment, whereas 45.45% of assisted conceptions required treatment. Of infants with low birth weights between 750 g and 1,499 g, 2% of natural conceptions required ROP treatment, and 5.62% of assisted conceptions required treatment.
“Assisted conception placed infants at a greater risk for ROP requiring treatment, and the risk was higher in the infants who were born of the lightest weight,” Dr. Sun said. “Interestingly, the mean gestational age at which treatment was required was higher for assisted conception patients rather than in natural conception patients.
“In the future, we hope to try and understand what it is about assisted conception that is associated with an increased risk of reaching ROP that needs treatment,” she said.
New IOL minimizes contact with biomaterial
A specially designed “bag-in-the-lens” IOL shows promise in pediatric cataract cases because of its minimal contact with biomaterial, the lens’ developer said in a presentation.
 Marie-José Tassignon |
Marie-José Tassignon, MD, said the new IOL was developed specifically for children to minimize contact with biomaterial that can cause lens epithelial cell damage and the resulting loss of elasticity in the capsular bag. She said she performs this implantation primarily for pediatric cataracts, which is what she encounters in European children.
The three pieces of the lens create a groove around the optic and between the haptics, where the IOL can secure the edges of both the anterior and posterior capsulorrhexis, leaving the only contact of the lens with the capsular bag edges, she said.
The surgical procedure to implant the lens consists of standard cataract removal with the exception of Dr. Tassignon’s technique for anterior and posterior capsulorrhexis, which she performs with the aid of a specially designed tension ring, she said.
Dr. Tassignon described the unique aspects of the procedure. She said the procedure required more skill and was more difficult than standard cataract removal procedures.
After removing the cataract, she said she does not fill the capsular bag with viscoelastic, but instead, she places viscoelastic in front of the anterior capsule to force the anterior and posterior portions of the bag together, and then she cleans the bag with both capsules touching.
Dr. Tassignon performs her anterior chamber capsulorrhexis with the aid of the ring and then uses the anterior chamber capsulorrhexis outline to guide her creation of a posterior capsulorrhexis of the same size.
“The vitreous body behind the capsule is important because it is the space used to implant the posterior part of the haptic,” she said. “The posterior capsule comes out more anteriorly and close to the border.”
The lens size is selected based on preoperative biometry using the lens sizing formula of Abhay R. Vasavada, MD, she said.
Dr. Tassignon said in almost all of the cases that she has implanted, at postop follow-up, the axis remains clear, provided both capsules are in the groove.
“I had one case where I didn’t look carefully enough to ensure the anterior and posterior portions were in the groove, and an opacification of the lens developed,” she said.
The advantage of using this IOL is that the capsular bag remains flexible and the lens can be re-implanted, Dr. Tassignon said.
“The technique doesn’t allow epithelial cells to migrate into the capsule, which is sealed and within the lens haptic,” she said.
Congenital cataracts successfully removed with 25-gauge vitrectomy tools
Use of 25-gauge vitrectomy tools in pediatric patients was successful for removal of congenital cataracts, a surgeon said.
 Kevin Y.H. Chee |
“Our opinion is that the 25-gauge system confers several advantages. It’s a safe procedure, and it allows for precise control of surgery,” Kevin Y.H. Chee, MBBS, said. “Issues with instrumentation are not significant, and we feel this system really does make a huge difference.”
The retrospective, noncomparative case series looked at 20 eyes of 14 patients who underwent surgery at a mean age of 14 weeks.
“We did surgery as early as 10 days and as late as 48 weeks,” Dr. Chee said.
Each of the patients underwent diagnostic screening to look for an underlying cause of the congenital cataract; 50% had no obvious cause.
The technique involved making two limbal side port incisions about 120° to 180° apart, he said. These ports could be made with a trocar from the 25-gauge vitrectomy pack or a separate 0.6-mm knife.
Dr. Chee said the first 17 cases were performed with the trocar, and 16 of these cases had wound leaks, but in the last three procedures, the surgeons used the knife and did not have any leakage.
The patients underwent anterior capsulotomy, lens aspiration, posterior capsulotomy and anterior vitrectomy and were left aphakic, he said. The wounds were hydrated and sutured. Postoperatively, all of the patients received treatment for amblyopia.
“Of our 20 cases, we were able to successfully complete the surgery in 95% of patients,” Dr. Chee said. One case had a fibrous anterior capsule that required the surgeon to switch to a 20-gauge system.
There were no intraoperative complications, and mean follow-up was about 18 months, in which no major complications occurred, except one eye developed ocular hypertension, he said.
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