ESCRS focus is on science of ophthalmology

Eliminating capsular opacification and meeting patients’ refractive expectations through customized surgery were some of the highlights from Munich.

MUNICH, Germany – The science that lies behind new ophthalmic technologies was an overarching theme at this year’s European Society of Cataract and Refractive Surgeons meeting, held here.

In both main threads of the meeting – cataract and refractive surgery – the emphasis was on the advances in existing technologies rather than on surgical techniques. The biocompatibility of IOL materials was the focus of the Ridley Medal Lecture, and many refractive sessions focused on customizing surgery to meet patients’ expectations — with or without customized ablation playing a role.

The term “customized vision” is now being applied beyond wavefront-guided corneal surgery. Surgeons are beginning to consider options to tailor vision to the patient’s needs and desires before proceeding with even medically necessary ocular surgery, not only elective procedures.

Sessions on glaucoma management played a smaller role at this year’s meeting, with symposia and posters focused mainly on medication use to eliminate potential complications from surgery.

The Breaking News session, immensely popular last year, was again one of the best attended sessions. Its goal is to introduce surgeons to cutting-edge theories and technologies too new to have been included in the initial program, according to Paul Rosen, FRCS FRCOphth, chairman of the session.

Since the time of last year’s meeting, several customized wavefront ablation systems already in use in Europe have been approved for use in the United States. Presentations on the newest clinical data on patients who have undergone customized refractive procedures piqued attendees’ interest.

IOL technologies are evolving as well, as demonstrated by a multitude of sessions dedicated to accommodating IOLs, new optic designs, new material compositions, capsular opacification and presbyopia.

Attendance at this year’s meeting was 3,100, a slight increase from last year. ESCRS president Ulf Stenevi, MD, noted in the opening session that there were more poster presentations submitted this year than in any previous year.

Following are some other highlights of the meeting. Many of these items appeared originally on OSNSuperSite.com as part of our daily coverage from the meeting. Look for more in-depth coverage of these and other presentations at ESCRS in upcoming issues of Ocular Surgery News.

REFRACTIVE

Zernicke may not be enough

Translating data from Shack-Hartmann diagnostic readings into Zernicke polynomials for customized refractive treatment is a challenge that still needs work, according to a refractive surgeon speaking here.

The currently used algorithms “work on virgin eyes, but we need more information to accurately assess more complicated eyes,” said Douglas Koch, MD. According to Dr. Koch, current methods for calculating Zernicke polynomials are dependent upon pupil size and do not adequately characterize sharp small features of the eye.

“Zernicke works well in normal eyes, but to try and reduce aberrations, we need a more precise algorithm,” he said. Better mathematical analysis may hold the key to a reduction in the aberrations induced during laser surgery, he said.

Dr. Koch described a study in which Zernicke reconstructions were compared to reconstructions using an alternative model. The study included reconstruction of wavefronts corresponding to control plastics and 30 eyes measured with a Shack-Hartmann sensor.

In the plastic and real eyes, the accuracy of the alternative method was “almost always higher than that of the Zernicke method up to the 12th-order polynomials,” Dr. Koch said.

Multifocal phakic IOL

A multifocal phakic IOL can be an efficient, potentially reversible refractive surgical option for patients with hyperopia, according to the IOL’s developer.

Georges Baikoff, MD, spoke on the use of a bifocal anterior chamber phakic IOL. He shared the results of his personal study using the lens during a symposium on hyperopia.

In his study, 55 eyes of 33 patients were implanted with a bifocal phakic IOL. Nine eyes were myopic and 46 eyes were hyperopic. Follow-up ranged between 2 and 20 months.

Patients all had anterior chamber depths greater than 3.1 mm and no anterior segment disease.

Mean refraction decreased from +1.8 D preoperatively to –0.12 D postop. Mean postop uncorrected visual acuity was 0.78, and 84% of patients were 20/30 or better and could read J1 or J2.

Dr. Baikoff noted that one lens was explanted due to the patient’s displeasure with the intermediate vision it provided, and three were explanted due to poor near vision.

He said there was some incidence of glare and halos, but patients accepted these. There was also an acceptable loss of contrast sensitivity compared to preop, he said.

“It is mandatory to tell patients that this is a compromise between excellent vision with spectacles and good vision with the IOL,” Dr. Baikoff said.

He noted that in using anterior chamber phakic IOLs, accurate biometry is necessary to ensure that patients have sufficient anterior chamber depths. Shallow anterior chambers are prone to angle closure, and there is risk of endothelial cell loss, he said.

Thin LASIK flaps, good results

A thin LASIK flap does not prevent patients from achieving good visual acuities similar to those seen with thick flaps, according to one study.

Paolo Garimoldi, MD, conducted the study to evaluate the effect of using an intentionally thin LASIK flap in order to preserve a thicker residual stroma.

Fifty eyes of 26 patients were included in the study. Flaps were created using the Moria M1 manual microkeratome with a 130-µm plate head.

Dr. Garimoldi said he used this keratome because the thickness of the flap it creates can be varied according to the speed of the cut. A thinner flap is created as the cutting speed is increased, he said.

Pachymetry measurements were taken after lifting the flap and after laser ablation with the Technolas 217 excimer laser (Bausch & Lomb). Postoperative follow-up was done at intervals up to 1 year.

Flap thickness varied between 77 µm and 120 µm, with an average thickness of 87 µm.

Dr. Garimoldi said no difficulties were encountered in managing the thin flaps, and all flaps were clear at 3 days follow-up. No complications relating to the condition of the flap were reported.

He said 43 eyes (86%) achieved 10/10 uncorrected visual acuity, and 45 eyes (90%) maintained postoperative best corrected visual acuity (BCVA) at the preoperative level. Two eyes gained one line of BCVA and four eyes lost one line of BCVA. At 1 year follow-up, 42 eyes (84%) maintained an uncorrected visual acuity of 10/10 and 43 eyes (86%) maintained their preoperative BCVA level.

Business news from ESCRS

Allegretto awaits U.S. approval An approval before year-end in the United States for the Allegretto excimer laser will increase WaveLight’s presence to more than 33 countries for its refractive laser systems, said Manfred Drax, MD, chief operating officer for WaveLight, during a press conference here. The U.S. application was based on clinical data from more than 900 eyes treated for myopia and “slightly more if you include the hyperopic patients as well,” said Max Reindl, president of WaveLight. While specific refractive error correction ranges are not allowed to be made public before approval, Mr. Reindl said the Allegretto is “comparable to other systems on the U.S. market.” The overall worldwide market for refractive lasers will continue to grow, “in the next year more in Asia than other markets,” Mr. Reindl said. “There are no serious alternatives to the excimer laser – there are no IOLs available, there is no femtosecond technology that’s a real alternative to excimer laser.” As a result, he said, there is a “huge market over the next 2 to 5 years for replacement machines.” Dr. Drax spoke about the Allegretto Wave Eye-Q, the company’s customized wavefront ablation machine. “We will assume a market leadership position with this product,” he said. The Eye-Q differs from currently approved customized systems because “it’s custom ablation with an individual approach,” he said. According to company materials, the Eye-Q includes a cross line projector that “enables more precise correction of astigmatism and higher-order aberrations with a defined axis.” Repetition rates on the laser have been increased to 400 Hz, allowing surgeons to perform up to 6 D of correction for myopia on a fully corrected optical zone of 6.5 mm in 15 seconds, company materials state. Gearing up for its entry into the U.S. market, the company has opened an office in Virginia. Once the Food and Drug Administration grants marketing approval to the Allegretto, WaveLight and Lumenis will jointly market the laser in the United States. B&L launches Zyoptix 100, Oxane HD Bausch & Lomb’s customized wavefront system, Zyoptix, has been updated to include an iris recognition tracker and a 100 Hz laser source, according to the company, The newest iteration, called Zyoptix 100, was launched here. According to B&L officials, to date more than 100,000 procedures have been performed worldwide with the Zyoptix system, and officials hope to receive Food and Drug Administration premarketing approval soon. The company also introduced Oxane HD for the treatment of complicated retinal detachments during the meeting. Oxane HD is a mixture of silicone oil and partially fluorinated olefin, according to company materials. The heavier-than-water tamponade has a specific gravity of 1.02 and a medium viscosity of 3.300 mPas, according to company information. The eye tracker features a camera-sampling rate of 240 Hz, according to the company. “The clinical trial results for the Eyetracker are on par with the U.S. Zyoptix FDA results, which are the best reported data to date,” according to company materials.

‘Aberropia’ and refractive error

A recently described entity separate from sphere and cylinder may be responsible for some refractive distortions, according to a poster presentation.

Vidushi Sharma, MD, FRCS (Edin), and colleagues at the All India Institute of Medical Sciences identified the refractive error, which they dubbed “aberropia,” in a retrospective review of 16 eyes of 10 patients who underwent LASIK with wavefront. Aberropia is a condition in which reduced visual acuity cannot be explained by a patient’s seemingly normal corneal topography.

All patients had visual acuities of 20/32 (0.63) or worse before undergoing LASIK with the Bausch & Lomb Zyoptix system. Postoperatively, all patients improved by at least 2 lines of Snellen acuity. At 1 month postop, 70% of patients were within 0.5 D of intended correction and 90% were within 1 D.

Overall, 93.75% of patients achieved BCVA of 20/20 or better, 25% achieved 20/16 or better and 25% achieved a BCVA of 20/10.

Zyoptix and contrast sensitivity

Gordon Balazsi, MD, spoke about increase in contrast sensitivity from preoperative levels and improvement in night vision postoperatively using Bausch & Lomb Zyoptix treatment.

“This statistically significant result has never been seen in refractive data before,” he said at a press conference introducing the Zyoptix 100 system.

The updated system’s iris recognition tracker includes identification and compensation for cyclotorsion, shift in pupil center and z-axis, Dr. Balazsi said. Optimal choice of 2-mm or 1-mm laser spot size is also offered.

After treating more than 5,000 patients himself with the Zyoptix system, Dr. Balazsi said “everyone is treated with Zyoptix unless I can find a reason not to treat them with the Zyoptix.”

Combo of phaco and LASIK

A combination of cataract surgery with photoablation can be used to reduce existing astigmatism, according to a study.

Luis A. Rodriguez, MD, and colleagues evaluated 20 eyes of 14 patients with myopia and more than 2 D of astigmatism who underwent the combined procedure. In the surgical procedure a LASIK flap was made with the Moria M1 microkeratome and allowed to stabilize prior to phacoemulsification. After phacoemulsification and implantation of an Alcon AcrySof IOL, patients underwent laser ablation.

Preoperatively, the mean astigmatism in the 20 eyes was –3.35 D, and the spherical error ranged from –1.75 D to 1.5 D. After making the flap, the spherical error increased an average of +1.1 D. Cylinder was reduced to a mean –2.3 D.

Following phaco and IOL implantation, the spherical equivalent of the eyes ranged from –0.75 D to –2.25 D, with a mean of –1.11 D. This was reduced to a mean of +0.75 D after photoablation.

According to Dr. Rodriguez, creating the LASIK flap has a flattening effect on the cornea, which stabilizes at around 4 weeks after the cut.

ESCRS meeting in Germany for first time

MUNICH, Germany — At the opening general session of the 21st Congress of the European Society of Cataract and Refractive Surgery, Ulf Stenevi, MD, current president, expressed his enthusiasm for the event and its extensive scientific program, noting there were more poster presentations submitted than in any previous year. He also noted that this is the first year the annual meeting has been held in Germany, but that ESCRS has enjoyed a close relationship with German ophthalmologists since the ESCRS society’s inception in the early 1980s, with the second meeting organized by the German ophthalmologist Karl Jacoboi, MD. In addition, many other German surgeons have contributed to the society over the years, he said. In particular, he noted Thomas Neuhann, MD, who has served as a past president of the ESCRS, and numerous members of the ESCRS board, including Tobias Neuhann, MD; Jorg Krumeich, MD; and Thomas Kohnen, MD. “I am delighted that we are extending our close relations with our German colleagues in a particular way during the Congress, through close collaboration with the DGII, the German Speaking Society of Cataract and Refractive Surgery,” Dr. Stenevi said. Toward the end of his speech, he welcomed Marie-Jose Tassignon, MD, who is currently secretary of the society and will be president of ESCRS next year. Following Dr. Stenevi’s speech, David Spalton, MD, announced the winners of the best poster presentations. Tat-Keong Chan, MD, won first prize in the cataract category for his study, “Nested-polymerase chain reaction for the rapid detection of microbes implicated in infectious endophthalmitis.” Second place was awarded to Gerd Auffarth, MD, for “Corneal surface temperature and phaco energy profiles during phacoemulsification with the AMO Sovereign with White Star Technology.” In the refractive category, Mike Holzer, MD, won first prize for his study, “Combination of t-PTK and autologous serum eye drops for treatment of recurrent corneal erosions.” Second place in the refractive category was awarded to Tae-Im Kim, MD, for “Mitomycin C inhibits recurrent avellino dystrophy after phototherapeutic keratectomy.” Per Montan, MD, was awarded the Kiewiet de Jonge Award for his paper “Prophylactic intracameral cefuroxime: Efficacy in preventing endophthalmitis after cataract surgery.” The award is presented to the author of the best European paper published in the Journal of Cataract and Refractive Surgery during the previous year. After the winners of best poster papers were announced, Richard Packard, MD, announced the winners of the 2003 video competition. For the educational video category, Howard Gimbel, MD, from Canada was awarded first place for his video “Laser plume risk.” Roger Steinert, MD, was awarded second place for his video “Dr. Zernike’s vision,” and Kerry Solomon, MD, was awarded third place for “Eye movement and laser tracking systems: The myth uncovered.” For the innovative video category, Jorg Krumeich, MD, from Germany won first place for the video “Corneal ring in perforating keratoplasty.” Kimiya Shimizu, MD, won second place for “Preloaded injector,” and Takayuki Akahoshi, MD, won third place for “Ultra-low energy phaco.” In a new category introduced this year, called new contributors, Khiun Tjia, MD, was awarded first place for “Aqualase: The quest for ultimate safety in lens refractive surgery.” Tushar Agarwal, MD, was awarded second place for “Rotational autokeratoplasty and rotational keratoplasty,” and Li Lim, MD, was awarded third place for “Combined lamellar and penetrating keratoplasty in the treatment of interstitial keratitis with peripheral corneal thinning.” Iqbal Ahmed, MD, from Canada won first place in the scientific category for his video, “Capsular tension segment: Next step in effective management of profound zonular dialysis.” Hiroko Bissen-Miyajima, MD, was awarded second place for Real-time observation of IOP changes during keratome suctioning in LASIK,” and Nick Mamalis, MD, won third place for “Ultimate small incision intraocular lenses.” For the final category, special cases, first place was awarded to Mana Tehrani, MD, from Germany for “Customized IOLs in an odd eye: The two toric IOLs concept.” Roberto Belluci, MD, won second place for “A new flip for combined glaucoma and cataract procedures.” Mittanamalli Sridhar, MD, won third place for Ipsilateral rotary autokeratoplasty: Alternative procedure to penetrating keratoplasty in nonprogressive central corneal ulcers.” Thierry Clidiere, vice president of Alcon for Europe, Middle-East and Africa, presented the award for the best video overall to Graham Barrett, MD, of Australia, for his video called simply “Intelligent tubing.” Dr. Barrett is also the recipient of the Ridley Medal and presented the Ridley Medal Lecture.

Bandage lens for LASIK

Use of a bandage contact lens did not prevent microstriae following LASIK and may have been detrimental to the postop visual acuity in a study reported here.

Walter Sekundo, MD, reported 1-year results of a two-center, prospective, randomized trial he conducted with H. Burkhard Dick, MD.

In the study, one eye each of 100 patients was treated after LASIK with ofloxacin drops and dexamethasone jelly followed by the application of a patch. The fellow eye was treated with a bandage contact lens soaked in ofloxacin and dexamethasone and applied immediately following LASIK.

Patient preferences and reasons for their preferences were evaluated. Uncorrected visual acuity was evaluated at 3 months postop. Flaps were evaluated for striae using retroillumination photography.

The study found that 54% of patients reported disliking the bandage contact lens, citing the presence of a foreign body sensation most often as their reason. In contrast, 27% of patients said they preferred the eye that received the bandage contact lens. They cited a feeling of protection most often as their reason. The remaining 19% of patients expressed no preference.

Dr. Sekundo said the eyes receiving the bandage contact lens also showed slightly worse visual acuities (0.6) than patched eyes (0.7), although this difference was not statistically significant.

Shack-Hartmann variability

A study comparing three Shack-Hartmann wavefront analyzers found variations among their measurements of patients’ higher-order aberrations.

Helga Sandoval, MD, and colleagues compared wavefront measurements made using the LadarWave (Alcon), WaveScan (Visx) and Zywave (Bausch & Lomb) aberrometers.

In the study, 99 patients underwent cycloplegic refraction followed by evaluation of higher-order aberrations using each system. A 3.5-mm optical zone was used during the measurements for both the LadarWave and the Zywave. A 4-mm optical zone was used with the WaveScan.

The WaveScan consistently measured sphere lower than either the Zywave or LadarWave, which measured sphere almost equally, Dr. Sandoval said. The Zywave measured cylinder lower than either the WaveScan or the LadarWave, she said.

The LadarWave and the Zywave measured total root mean square (RMS) aberrations about equally, while the WaveScan consistently undermeasured total RMS values, she said.

Dr. Sandoval acknowledged that Visx advises against dilating patients’ pupils when using the WaveScan aberrometer. Because all pupils were dilated before the measurements were taken, this could have resulted in the lower readings, she said.

LASIK for post-RK ametropia

LASIK can correct residual ametropia in eyes that have had previous radial or astigmatic keratotomy, according to a poster presentation.

Hamid Khakshoor, MD, and Elham Froozanfar, MD, of the Mashhad University of Medical Sciences in Iran, evaluated LASIK for correcting residual myopia and astigmatism in eyes that had previously undergone RK or combined RK and AK.

To be included in the study, patients had to show good healing of the incisions, absence of epithelial cysts and fibrosis and absence of corneal ectasia.

Sixteen eyes of 11 patients were included, with an average patient age of 36. All patients had undergone RK at least 1 year before undergoing LASIK correction. Four eyes had undergone both RK and AK, and 12 eyes had RK alone. Visual acuity and refraction were evaluated preoperatively and at 1 day, 1 and 6 months and 1 year.

There was an average improvement in vision from 3/10 preop to 11/10 at 6 months postop. No significant change in refraction was seen from 6-month to 1-year follow-up, and no major ocular complications occurred, the authors said.

Transepithelial PTK

Transepithelial phototherapeutic keratectomy may prevent the hyperopic shifts often seen following standard phototherapeutic keratectomy for recurrent corneal erosions, according to a presentation.

Mike P. Holzer, MD, and colleagues with the Heidelberg IOL and Refractive Surgery Research Group in Germany evaluated 25 patients who underwent transepithelial phototherapeutic keratectomy (t-PTK) for recurrent corneal erosions. Average patient age was 41 years.

Dr. Holzer said 80% of the patients healed and did not suffer further corneal erosions. Four patients (16%) had one occurrence of erosion following surgery. One of the patients who experienced recurrence was treated with additional t-PTK only, and the other three were treated with autologous serum only. No further complications were seen.

Conventional PTK requires abrasion of the entire corneal epithelium, which can cause astigmatism and a hyperopic shift, the authors noted. In contrast, t-PTK ablates only a superficial epithelial layer. Because the rate of recurrent erosions is between 10% and 20% for both standard and t-PTK, and because t-PTK has the advantage of not causing a change in refraction, the authors suggested that t-PTK should be performed before a complete PTK.

Phakic IOL sizing

Angle-to-angle and sulcus-to-sulcus distances cannot be adequately predicted from external measurements such as the white-to-white distance, said Daniel Reinstein, MD.

The safety of phakic IOLs depends on direct, accurate measurements, and using the white-to-white distance to predict lens sizing is not effective, Dr. Reinstein said.

He and colleagues measured refraction, keratometry values, axial length and anterior chamber depth in 10 eyes with myopia and 10 eyes with hyperopia to determine the predictive power of external measurements when planning phakic IOL implantation.

Neither group demonstrated a significant correlation between either white-to-white and angle-to-angle measurements or white-to-white and sulcus-to-sulcus measurements. In hyperopes, white-to-white coupled with age and anterior chamber depth were used to create a reliable model for predicting angle-to-angle, but no such correlation was found in myopes, Dr. Reinstein said. White-to-white plus anterior chamber depth and sphere produced a good model for predicting sulcus-to-sulcus distance in myopes, but this correlation was not found for hyperopes.

“What was found is of limited use in practice,” he said.

CATARACT

Dual-optic accommodating IOL

A dual-optic design may prove useful for accommodating IOLs, according to one speaker. The combination of two optics in one IOL may increase the pseudoaccommodative effect of the lens, suggested Stephen McLeod, MD.

He spoke about a new lens in development by Visiogen that in both cadaver and rabbit eyes demonstrated less capsular contraction and capsular opacification than control plate-haptic IOLs.

The Synchrony lens is 2.2 mm thick, with an anterior optic linked via spring-loaded haptics to a posterior optic, he said. The one-piece silicone lens has 5.5-mm diameter optics. It is 9.5 mm in overall length and 9.8 mm wide. The anterior optic’s power is between 30 and 35 D and the posterior optic’s power from –1 to –15 D, he said.

In cadaver eyes, the lens was “readily manipulated” through an incision of less than 4.5 mm and unfolded in the capsular bag, he said.

Clinical trials of the lens have just begun, Dr. McLeod said, and its biomechanical safety is being assessed.

During a question-and-answer period, Dr. McLeod noted that a number of dual-optic accommodative IOL systems are being developed, and each has its own biomechanism of action.

Innovations heralded in Breaking News session at ESCRS

MUNICH, Germany – From dual-optic IOLs to solid-state lasers for refractive surgery, this year’s Breaking News session at the European Society of Cataract and Refractive Surgeons meeting piqued interest across the subspecialties. Takayuki Akahoshi, MD, described a “knuckle” phaco tip, designed to increase both safety and efficacy in cataract surgery. His newest design phaco tip has a smooth spherical surface, so the posterior capsule is not ruptured even if the tip comes in direct contact with it, he said. The tip itself is bent at a 20° angle, and irrigation fluid flows out laterally. “This tip can be used with the (Alcon) Legacy or Infiniti,” he said. “The nucleus can be removed in 2.6 seconds with very low energy. Total ultrasound time can be reduced significantly.” Georg Korn, MD, said he believes direct solid state lasers “are excellent candidates for true scanning small-spot lasers for laser vision correction and customized laser vision correction.” He spoke about the LaserSoft, a diode-pumped solid-state laser from Katana Technologies, of Kleinmachnow, Germany. Dr. Korn is managing director of Katana. He noted that solid state lasers are less expensive to operate than excimer lasers, and they can give the surgeon “excellent gaussian beam spot distribution.” Matteo Piovella, MD, agreed with Dr. Korn. He reported 1-month results on 22 eyes using the LaserSoft. Mean residual sphere was – 0.24 D and mean cylinder was – 0.06 D. All patients were within 1 D of target. Anthony Maloof, MD, discussed the concept of sealed capsule irrigation, or SCI. He said using SCI, surgeons can selectively cause cell death in parts of the capsule without damage to the remaining capsule. In a rabbit study, he found that by sealing the capsulorrhexis, chosen cells can be killed and removed safely without further damaging the eye. “I am reminded of what Dr. Philippe Sourdille told us earlier in this Congress – you have to think of capsular opacification, not just posterior capsular opacification,” Dr. Maloof said. New methods such as SCI may be able to help surgeons avoid all capsular opacification, he said. Stephen D. McLeod, MD, spoke about a new dual-optic IOL from Visiogen, a one-piece silicone IOL with a 5-mm optic. It measures 9.5 mm in length and 9.8 mm in width, and it is 2.2 mm thick. The anterior optic ranges in power up to 35 D, and the posterior optic ranges in power from –1 to –15 D. Dr. McLeod said the dual-optic system can increase the optical effect caused by a given amount of lens movement, possibly increasing the accommodative amplitude that can be achieved by an IOL. Arturo Perez-Arteaga, MD, spoke about microincision refractive lens exchange, or MIRLEX. The procedure involves extraction of the clear lens and the implantation of a microincision IOL with the ultrasmall-incision techniques currently gaining popularity for cataract extraction. But in this case the procedure is done for refractive purposes, not to remove a cataract.

Relaxing incisions for multifocal

Limbal relaxing incisions to reduce astigmatism may improve outcomes with the Array multifocal IOL, according to a study presented here.

Anil Aralikatti, MD, and colleagues prospectively evaluated the use of limbal relaxing incisions (LRIs) during cataract surgery in 15 patients with more than 1 D of astigmatism.

The average patient age was 77. Seven patients were male. Corneal astigmatism was measured using the Orbscan II. LRIs were applied based on a modified Koch nomogram that accounts for both the type of astigmatism and age of the patient, Dr. Aralikatti said.

Postoperatively, astigmatism was reduced an average of 0.89 D (45%), Dr. Aralikatti said. There were no intraoperative complications.

Visual acuity improved in all eyes postoperatively. Eleven patients (73%) had uncorrected distance visual acuity of 6/9 or better, and 12 patients (80%) had uncorrected near vision of J3 or better. Mean astigmatism was reduced from 1.96 D to 1.07 D postop.

Modified LRI for astigmatism

A modified LRI technique results in “excellent uncorrected visual acuity after cataract surgery” but is less effective at reducing astigmatism than standard limbal relaxing incisions, according to a poster by Eriko Fukuyama, MD.

Dr. Fukuyama reported on 387 eyes that underwent different procedures: 84 eyes underwent cataract surgery alone, 123 eyes underwent astigmatic keratotomy concurrently with cataract surgery, 116 eyes underwent LRIs during cataract surgery and 64 eyes underwent modified LRIs during cataract surgery.

The mean keratometric cylinder decreased compared with preoperative levels in the astigmatic keratotomy group, the LRI group and the modified LRI group.

“Compared to corneal relaxing incisions and usual LRI, new LRIs are a weaker corrective procedure,” Dr. Fukuyama reported. In general, he said, LRI procedures cause few complications such as corneal perforation, overcorrection and astigmatism.

Capsule polishing and PCO

Extensively polishing the anterior capsule following cataract removal may negatively affect the rate of posterior capsule opacification, a small study suggests.

Matthias Wirtitsch, MD, and colleagues evaluated the effects of extensive polishing of the capsule in 96 eyes of 46 cataract patients.

Dr. Wirtitsch said the differences in PCO rates were not statistically significant, but it appeared in the study that extensive polishing of the capsule increased the risk of developing PCO. He said this may be because extensive polishing decreased the amount of antifibrotic activity.

Patients were randomly assigned to be implanted with the Advanced Medical Optics SI-40 IOL or the Bausch & Lomb Silens 6 IOL. Both are round-edged silicone lenses.

Dr. Wirtitsch said all patients underwent cataract surgery using the same technique, with the lens implanted in the bag in all cases. The capsule in one eye of each patient was extensively polished using a cannula, while the fellow eye was not polished to serve as a control.

PCO was evaluated using standard coaxial retroillumination photography at 1 year and 3 years follow-up.

By 3 years, eight patients required Nd:YAG capsulotomies in both eyes; six patients in the Silens group and two patients in the SI-40 group.

Over the course of follow-up, four patients in the Silens group and two patients in the SI40 group required Nd:YAG capsulotomies in their unpolished eyes, while eight Silens patients and four SI40 patients required capsulotomies in their polished eyes.

Strategies in pseudoexfoliation

Enlarging the iris with retractors in patients with pseudoexfoliation (PEX) syndrome can ease creation of the capsulorrhexis during cataract surgery, according to Charlotta Zetterstrom, MD. The retractors can also be used to steady a loose natural lens during capsule removal, she said.

Dr. Zetterstrom, of Sweden, discussed the indications and techniques for use of iris retractors and capsular tension rings in a symposium on PEX.

According to Dr. Zetterstrom, patients with PEX syndrome typically develop cataracts earlier than other patients and typically have smaller pupils as well.

She said the biggest problem is that PEX patients have weak zonules, which increases the likelihood of a loose natural lens. This also increases the chance of a loose IOL and subsequent late complications such as IOL displacement.

To overcome these problems, Dr. Zetterstrom said retractors can be used to expand the iris during surgery, and a capsular tension ring can increase the stability of the bag.

In addition to expanding the iris, the retractors can also be used to hold the patient’s natural lens steady while the capsulorrhexis is made, she said.

During phacoemulsification, she said, a capsular tension ring can be inserted prior to completing removal of lens material to increase chamber stability. Once the ring is in place, phaco can proceed as normal, she said.

Dr. Zetterstrom warned that PEX patients are prone to late complications, with lens dislocation a particular concern. Because of this, she recommends suturing both the IOL and the capsular tension ring in place in these patients using 10-0 nylon.

Another speaker said modifications of cataract surgical technique may be helpful in patients with pseudoexfoliation syndrome.

Adapting the procedure to the condition of the patient can lead to better postoperative outcomes, said Albert Galand, MD, of Liege, Belgium.

“One of the major problems in performing phacoemulsification on PEX patients is postoperative IOL dislocation due to zonular dehiscence during lens removal and cortical cleanup,” Dr. Galand said. “This risk is enhanced when there is a small pupil and small rhexis.”

The iris can be efficiently expanded by simple stretching and injection of a heavy viscoelastic, Dr. Galand said. The dilation will persist until the end of the procedure, and iris retractors may not be needed, he said.

Safety can be increased during capsulorrhexis by using a heavy viscoelastic, he said. Forceps or scissors can then be used to gently and slowly peel back the capsule.

According to Dr. Galand, almost any phaco technique can be used to remove the lens in these patients. However, he warned that the lens should be moved forward to prevent it from dropping into the vitreous.

He said it is also better to perform phaco in these patients using a small-incision procedure and with small-diameter instruments, with irrigation placed in the center of the chamber.

Lens keeps capsule clear

Patients implanted with a new sharp-edged IOL maintained clear anterior and posterior capsules after 3 years follow-up, according to Philippe Sourdille, MD, who discussed the Concept 360 IOL from Cornéal. The lens is not available in the United States.

Dr. Sourdille said the development of square-edged lens designs has already led to dramatic reductions in posterior capsular opacification (PCO). But anterior capsular opacification (ACO), which can occur with all lens materials and current lens technologies, has been a neglected problem, he said.

In ACO, lens epithelial cells migrate to the anterior surface of the lens optic, blocking vision.

Patients implanted with the Concept 360 IOL from Cornéal have maintained clear anterior capsules even after 3 years, Dr. Sourdille said.

The Concept 360 IOL is a hydrophilic acrylic square-edged IOL that is implanted in the capsular bag. It features six haptics that encircle the entire lens, providing a tension ring effect. Additionally, the haptics are angled 10° to the posterior, which helps prevent the lens optic from contacting the anterior capsule.

Dr. Sourdille said the combination of these features has resulted in a stable lens that is resistant to both PCO and ACO.

He said ACO is prevented because the angulation of the optic prevents contact with the migrating lens epithelial cells, allowing the cells to be flushed away by the aqueous fluid. In his pilot study, at 3-year follow up transparent anterior capsules were still visible, he said.

ESCRS highlight: Ridley Medal Lecture recaps the state of hydrogel IOLs

Graham Barrett MUNICH, Germany – Graham Barrett, MD, the recipient of this year’s Ridley Medal, spoke here about how hydrogel IOLs have evolved, where they stand and where future advances may take them. Dr. Barrett’s presentation was one of the highlight’s of this year’s European Society of Cataract and Refractive Surgeons meeting. “I want to offer my deepest appreciation to the board for the tremendous honor they have bestowed upon me,” Dr. Barrett told ESCRS attendees. “It is truly a privilege to present the 2003 lecture.” Dr. Barrett briefly explained some of the science behind hydrophilic and hydrophobic IOLs. He noted that he encountered resistance initially, years ago, when he questioned why IOLs were being made only from PMMA. “My personal interest was in improved biocompatibility,” he said. He saw potential for fully hydrated flexible implants, and he was granted this wish in 1976, he said, when Edward Epstein, MD, implanted the first hydrogel lens in a living subject. “There are several unique characteristics of hydrogel lenses that keep them attractive,” Dr. Barrett said. “The hydrophilic surface is one, which is why there is so little damage to the tissue; improved biocompatibility over other lens material; thermal stability, which allows the lens to be autoclaved; and optical properties that make the lens inherently resistant to YAG laser. In addition, the mechanical properties allow the lens to be folded and implanted,” resulting in a truly smaller incision than could be used with PMMA lenses. Dr. Barrett touched upon complications that have been reported with all IOL types. “There’s internal crazing with PMMA, yellowing with silicone, glistening with hydrophobic acrylic lenses and opacification with hydrophilic acrylic lenses,” he said. Dr. Barrett said he believes the problem of calcification in hydrophilic acrylic IOLs has been resolved. Specifically, he said a hydrogel lens created by Philippe Sourdille, MD, and being developed by Corneal will offer patients “improved safety and acuity” over current hydrogel lenses. Dr. Barrett reported on a study he conducted earlier this year, in which he measured higher-order aberrations in patients after cataract surgery and correlated the errors with the IOL material. “Patients with a high-refractive-index acrylic had the highest number of higher-order aberrations,” he said. “But can you achieve smaller incisions with these materials and maintain quality of vision?” He said he believes the answer is yes, and he pointed to the ThinOptX lens as an example. However, he said further evaluation of the optical quality of that IOL is needed. He noted other new ultrathin IOL technologies include the Acri.Tec lens, which is inserted with a microinjector. IOL design improvements will continue, Dr. Barrett said. And he is still anticipating future material improvements. “I am proposing the term hydro-elasto-gel for a lens that retains the positive qualities of both hydrogel and silicone materials, that can be folded wet or dry and inserted through a 2-mm opening or less. The optic will instantly unfold after insertion up to a 6-mm optic. Safety is improved and there is a reduced risk of astigmatism.” He concluded his lecture by thanking collaborators and predecessors.

Cefuroxime for prophylaxis

A regimen including intracameral cefuroxime seems to be an effective prophylaxis against endophthalmitis in cataract surgery, said Per Montan, MD. He was presented with the Kiewet de Jonge award at the annual meeting, and he addressed the possibility of efficient and reliable protection against postoperative endophthalmitis in his lecture.

“What do we really know about endophthalmitis? Only what’s published,” Dr. Montan told attendees. “What’s an acceptable rate? Zero percent, but is that feasible?”

Cefuroxime is “an uncontroversial selection as a prophylactic,” he said, because it creates no endothelial damage and no apparent retinal toxicity.

Dr. Montan said he reviewed 59 cases of endophthalmitis from 1990 to 1995. Of the causative organisms identified, only four strains were resistant to cefuroxime, he said. The drug is not effective against some strains of enterococci and some gram-negative organisms, he noted.

Using a combination of preoperative chlorhexidine and intracameral cefuroxime from 1996 to 2000, Dr. Montan reported a postoperative endophthalmitis rate of 0.06% after 33,200 cataract surgeries. In comparison, from 1990 to 1993, in 22,100 operations in which gentamicin was used, the incidence of postoperative endophthalmitis was 0.26%.

“In answer to my question, we are able to suppress endophthalmitis in a controlled environment,” he said.

GLAUCOMA

Glaucoma after keratoplasty

The incidence of glaucoma following penetrating keratoplasty was less than previously reported in a study presented in a poster here.

Melis Palamar, MD, and colleagues at Ege University in Izmir, Turkey, described a retrospective study of penetrating keratoplasty (PKP) performed in 214 eyes of 190 patients from November 1991 to January 2002.

Only 19 eyes (8.8 %) developed glaucoma following the procedure. Of the eyes that developed glaucoma postoperatively, nine already had glaucoma, controlled through medical therapy, before undergoing keratoplasty.

This study contrasts with previous reports that have shown an incidence of glaucoma following PKP ranging from 10% to 53% for all eyes.

The authors gave three possible explanations for finding a lower incidence of glaucoma in this study. First, the mean patient age was young, up to 12 years younger than in previous studies. Second, the indications for PKP may have been different; keratoconus was the indication for PKP in 41.6% of cases compared with 22.4% in a previous study. Third, topical cyclosporine A 0.1% was used in this study.

Needling and antimetabolites

Use of an antimetabolite before needling of a fibrotic filtering bleb after nonpenetrating glaucoma surgery can improve the chances of success of the revision, according to Ike Ahmed, MD. He discussed the role of goniopuncture and needling after nonpenetrating glaucoma surgery at a clinical research symposium.

Dr. Ahmed said episcleral fibrosis is a frequent cause of bleb failure after nonpenetrating glaucoma surgery. Bleb encapsulation can be managed either medically or surgically via needling, he noted. The addition of an antimetabolite to the needling procedure can induce remission of fibroblast proliferation, he said.

Dr. Ahmed described a retrospective, consecutive case series in which he used bleb needling in 21 eyes of 19 patients who had undergone deep sclerectomy with collagen implant. Eight patients were treated with adjunctive fluorouracil and 13 with adjunctive mitomycin. All patients underwent an initial Nd:YAG goniopuncture. Follow-up averaged 13.3 months.

In the needling procedure, 5-FU or mitomycin is injected into the bleb site approximately 7 mm posterior to the filtration site under topical anesthesia. To allow absorption of antimetabolite in the bleb and prevent its penetration into the eye through the filtration site, the surgeon waits 15 to 30 minutes before the needling is performed.

The needle is inserted posteriorly through the bleb. Once the needle enters the area under the flap, a rise in the bleb can be detected, indicating that flow of aqueous has been restored.

Dr. Ahmed said needling the bleb will usually suffice, but it is sometimes necessary to enter the anterior chamber to restore filtration.

Dr. Ahmed said he prefers mitomycin because it is more potent than 5-FU. Studies have shown it can reduce the need for additional revisions due to postoperative elevated intraocular pressure, he said.

In his study, patients who received mitomycin required statistically significantly fewer subsequent needlings than patients treated with 5-FU. Mitomycin patients required 1.1 ± 0.3 reinterventions compared to 2.8 ± 0.8 in the 5-FU group, he said.

VITREORETINA

New material for tamponade

Sebastian Wolf, MD, reported on repair of complex retinal detachments using a new heavier-than-water liquid for tamponade. He operated on 33 eyes of 33 patients ranging in age from 20 to 84 using Oxane HD (Bausch & Lomb), a mixture of silicone oil and partially fluorinated olefin.

Follow-up was a 1, 3 and 6 months and 1 year. At 5 weeks after removal of the heavy silicone oil (planned within 3 months of surgery), an additional follow-up visit was scheduled.

Dr. Wolf reported that at 6 months, 25 eyes had a visual acuity of 20/400 or better, and by 1 year all retinas had reattached.