The author is a correspondent for <I>Urology Times</I>, a sister publication.

Fred Gebhart

home

authors

fred-gebhart-0

By Fred Gebhart; Reviewed by Alan S. Crandall, MD

The introduction of phaco in 1967 was a defining shift in the treatment of cataracts, glaucoma, and complex infant eyes, as well as expansion in the provision of global eye care into the future.

“I originally trained in the 1970s. With intracapsular, and later, extracapsular surgery, your control of IOP usually was worse,” said Alan S. Crandall, MD, professor and director of Glaucoma and Cataracts, Moran Eye Center, University of Utah School of Medicine, Salt Lake City.

“With phaco, you suddenly have a three- to five-point drop in IOP after cataract surgery,” Dr. Crandall added. “That unexpected collision between phaco and glaucoma sparked a blossoming of technology that has brought us to micro-invasive glaucoma surgery (MIGS) devices and similarly, important innovations in low-tech treatments that are improving eye care around the world.”

The continuing development of phaco created a new category of combined cataract and glaucoma surgery that has become one of the most common ophthalmic surgical procedures in the developed world, Dr. Crandall said.

Intracapsular gave way to extracapsular procedures, but there was little innovation until the often contentious adoption of phaco, he noted.

“There is a clear progression from intracapsular to extracapsular to phaco to small incisions to small implants,” he said.

“The 1980s and 1990s were an exciting time in cataract surgery,” Dr. Crandall said. “But glaucoma surgery was pretty much trabeculectomy; there were some minor adjustments-mitomycin C here, selective laser trabeculoplasty there.”

It would take another decade for advances in cataract to move into glaucoma with successive generations of ever-smaller, ever less-invasive devices, he noted.

Learning from the unexpected lesson that phaco lowers IOP, generations of researchers have been searching for technologies and techniques that can be translated from one disease or treatment area to another.

Surgeons realized that their growing experience with smaller incisions in adult eyes could be translated directly to pediatric eyes. Pediatric conditions-such as Marfan syndrome or ectopic lentis that once had less-than-ideal outcomes-can now be treated much more successfully using Ahmed capsular tension segments and other techniques designed for adult eyes.

“The standard procedure for Marfan syndrome is lensectomy, vitrectomy, and then you sew a lens to the sclera,” Dr. Crandall noted. 

“Then you have fairly high rates of retinal detachment and secondary glaucoma,” he said. “When you apply what we’ve learned from phaco and small incisions and treating complicated adult eyes, you reduce the rate of both retinal detachment and secondary glaucoma in these kids to near zero. It’s a huge change.”

The numbers of patients are relatively small, he noted, simply because the prevalence of complex pediatric eye disease is relatively low. Thanks to technologies developed for complicated adult cataracts, late complication rates in pediatric patients have fallen dramatically.

Though phaco is the leading cataract treatment in advanced economies, the procedure is far too expensive for the vast majority of cataract patients in the rest of the world. Most ophthalmologists worldwide still rely on small incision extracapsular.

“How do you pay for cataract surgery in less-developed countries?” Dr. Crandall asked.

“You do it by helping ophthalmologists in those countries to develop their own centers of excellence where patients who used to fly to London, Japan, the United States, or Australia can get the same first-world phaco and premium IOLs without leaving home,” Dr. Crandall said.

Just one patient treated with phaco in a country, such as India, pays for nine other patients to get a first-rate, small-incision extracapsular cataract removal. Phaco technologies that developed from it are transforming vision care even for patients who cannot afford it, he noted.

There is no sign of slowdown in the pace of innovation, Dr. Crandall continued. Lasers continue to increase in performance and versatility. The latest development is a femtosecond laser that can reshape an IOL that has already been placed in the eye.

“Instead of doing a lens exchange, you can change the power of the existing lens by four D, plus or minus,” he said. “You can add or remove astigmatism. You can add or remove multifocal, all with the lens in the eye. And you can do it in 30 seconds.”

Innovation is also transforming low-tech procedures, he said-one of the latest developments being a handheld device (miLOOP, Iantech) that fragments any grade of cataract using a thin, super-elastic filament.

No laser, no phaco, and no external power source are needed, just a steady, surgical hand, he noted.

This article was adapted from Dr. Crandall’s delivery of the Charles D. Kelman Lecture at the 2017 meeting of the American Academy of Ophthalmology. He did not indicate any financial interest in the subject matter.

Articles

The 2017 Charles D. Kelman Lecture touched on three main areas-from the teaching of the phaco technique during the early years of phaco to use of phaco in glaucoma patients to the introduction of phaco to surgeons in developing countries.

Cataract, glaucoma collision sparks MIGS, other innovation

	All multifocal intraocular lenses (IOLs) are not created equal.

	Some multifocal IOLs use refractive optics and others use diffractive optics. Because the visual characteristics of the different types of optics are different, patients are likely to perceive that they have better vision with one type of lens over the other.

	Depending on their own visual needs and preferences, some patients will be happier with one type of IOL or the other.

	“A lot of the problems with multifocal IOLs come down to proper product selection,” said Detlev R.H. Breyer, MD. “Every doctor should understand how multifocal IOLs work or know the default modes of different IOLs. It is important to know which IOL to use for which patient.”

	Dr. Breyer, partner in Premium Eyes, a private practice in Dusseldorf, Germany, compared the performance of the Lentis Comfort MF15 (Oculentis), a refractive IOL, and the Tecnis Symfony (J&J Vision Care), a diffractive IOL.

	The Comfort lens is a purely refractive lens with a high light transmission. It is rotationally asymmetric with a sector-shaped segment on the anterior surface providing +1.5 D for improved intermediate vision. Due to a transition zone between both segments, it can be considered an extended-depth-of-focus (EDOF) lens rather than a bifocal IOL.

Image1. Distance-corrected monocular defocus curves for Comfort lens and the Symfony lens. (Image courtesy of Detlev R.H. Breyer, MD)

	The Symfony lens has a diffractive posterior surface that generates a continuous focus with an effective addition of about +1.78 D. Combining this diffractive posterior surface with a refractive anterior surface, the Symfony, a EDOF lens, provides reduced chromatic aberration leading to improved contrast sensitivity.

	In many ways, the two lenses are comparable, Dr. Breyer noted. Measured clinical defocus curves for Comfort lens and Symfony lens are virtually identical, with no statistically significant (p <  0.05) differences between mean visual acuity values from 0.0 D to -2.5 D (see Image 1).

	Measuring both IOLs on an optical bench, the modulation transfer function (MFT) focus through curves show similar characteristics. Symfony is somewhat better in the intermediate range, but it is difficult to translate optical bench values to clinical outcomes.

	In actual use, the two lenses show similar safety outcomes. In a retrospective comparison of the Comfort lens (1,281 eyes) and the Symfony lens (53 eyes) outcomes with presurgical assessment and follow up out to 90 days after implantation, there were no eyes with a loss of two or more lines and no significant difference between mean corrected visual acuities.

	The two lenses are also similar in terms of predictability, with no significant difference between the mean spherical equivalent.

	Binocular uncorrected defocus curves after surgery are also similar. Both lenses have good multifocal capability. The Symfony lens shows slightly better visual acuity at intermediate distances and the Comfort lens is slightly better at far. Where the two lenses differ is photopsic phenomena, especially halo and glare.

	Photopsia is a function of the different optical parameters in the two lenses, Dr. Breyer explained. Due to its higher intermediate addition, the Symfony lens allows users to read smaller print without glasses compared to the Comfort lens, but from experience, the Comfort lens produces less halos and glare.

	“Patients have to make a choice of what is more important–being able to read small print without glasses or being without halos and glare,” Dr. Breyer said. “If you want to be on the safe side, the refractive IOL is less trouble for patients because they do have less halos and glare.

	“But not every patient is afraid of halos and glare because they do not drive so much in the nighttime,” he added. “How happy the patient is with their lens depends very much on them choosing the right lens for their life and lifestyle.”

	The key to implanting multifocal lenses is matching the right lens to the right patient, he said. Too many ophthalmologists are not familiar enough with the optical differences between the two lens types to explain them. Others use technical language that may be correct but makes no sense to patients who are unfamiliar with optics.

Image 2. Halo and glare categories presented to the patient. (Image courtesy of Detlev R.H. Breyer, MD)

	“We show our patients possible photopic phenomena and show the defocus curves of the different IOLs and let them make the choice,” Dr. Breyer said. “I ask about their jobs, their hobbies, their family life, how they like to read, and in what kind of setting. We use simulation software to show them just what halo and glare look like in four categories–none, mild, moderate, and severe (see Image 2). They know they will have to make a compromise and they know what the different compromises will look like after surgery.”

	It is impossible to predict post implant photopsia precisely, Dr. Breyer added, but vision around age 30 can be a good guide. Patients who report no halos and glare while they were driving at night at age 30 will have mild halos and glare. Patients who had mild or moderate problems at age 30 are more likely to have severe halos and glare with a refractive IOL.

	“Many of the problems with multifocal IOLs occur because too many doctors implant whatever IOL they just heard about,” Dr. Breyer said. “They do not realize they are free to implant the right multifocal IOL for the right patient. When we individualize the lens choice to the patient, we have much better results.”

	This article was adapted from a presentation that Dr. Breyer delivered at the 2017 American Society for Cataract and Refractive Surgery meeting.

Match multifocal IOL to patient needs, preferences for best results

	Telemedicine is not a new concept. Physicians in Australia were using two-way radio to treat patients in rural Australia in the 1920s. Almost a century later, glaucoma is going remote.

	“In the glaucoma clinic of the future, patients will be checking their own eye pressure,” predicted Louis Pasquale, MD, professor of ophthalmology, Harvard Medical School, and director of Glaucoma Service and Teleretinal Program, Massachusetts Eye and Ear Infirmary, Boston. “They will be doing their own visual fields and imaging their own discs. This will convert the glaucoma clinic to focus on the patients who really need to be seen.”

 session and set the scene for changes that are already underway. The session was part of the New Horizons Forum at the 2017 Glaucoma 360 meeting.

	“‘Teleglaucoma’ is feasible and can play a major role in blindness prevention,” said Lama A. Al-Aswad, MD, MPH, associate professor of ophthalmology, Columbia University College of Physicians and Surgeons, New York. “Telemedicine and teleglaucoma are going to be an important part of how we take care of patients in the United States and worldwide.”

	Telemedicine is practicing medicine over a spatial or temporal distance by using electronic communications, Dr. Aswad explained. Glaucoma is an ideal candidate for telemedicine because patients tend to be older and less mobile. The disease is chronic and the technology exists for remote screening, diagnosis, and treatment.

	The Edward S. Harkness Eye Institute at Columbia University is testing “tele-ophthalmology” to screen for the four leading causes of blindness–cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy. Screening for visual acuity, non-contact tonometry, frequency doubling technology (FDT) perimetry, fundus imaging, and optical coherence tomography are loaded into a small truck that travels to screening sites.

	“We don’t have an ophthalmologist on the truck,” Dr. Al-Aswad said. “We send results to a central reading center. If the doctor decides the patient has potential for eye disease, we teleconference on the spot. It is a highly efficient use of resources to screen for eye disease and raise awareness.”

	In London, Visulytix is going one step farther. Instead of sending test data to an ophthalmologist for review, the company is developing an artificial intelligence (AI) system to screen test results.

	“The net result is above-human levels of diagnostic accuracy in a fraction of the time and at a fraction of the cost of a typical provider,” explained Sameer Trikha, MBA, FRCOphth, founder and chief medical officer. “We are developing a single algorithm, a single solution to screen for multiple eye diseases, including glaucoma, AMD, and diabetic retinopathy. It is quite conceivable that you can reach accuracies of between 85% and 99%, vastly superior to primary eye providers and equivalent to human experts.”       

	AI won’t replace clinicians, Dr. Trikha said. AI will handle the initial screening and reduce the incidence of false positives, streamlining workflow, and enabling ophthalmologists to focus on patients who need treatment.

	The next step is remote visual field testing, which is already here.

	The Visual Fields Easy App, designed for the iPad, is being used in Nepal and other remote locations for screening, said Ying Han, MD, PhD, associate professor of ophthalmology, University of California San Francisco.

	The more complex Melbourne Rapid Fields (MRF), also iPad-based, has a nearly 1:1 correlation between MRF results and a conventional Humphrey Visual Field (HVF) Analyzer. A free web-based perimetry test, Peristat, at 

, can be used on any computer screen 17 inches or larger.

	“Tablet and online field exams can be performed reliably and consistently,” Dr. Han said. “All have a strong correlation with HVF and can be good glaucoma screening tools.”

	The Eye Institute of Alberta also is using tele-ophthalmology. One program links patients and non-specialist providers in remote communities with specialists in Edmonton, Canada. Images and screening data are provided by optometrists.

	“We do the grading in Edmonton as a glaucoma specialist group,” said Karim Damji, MD, MBA, professor and chairman of ophthalmology, University of Alberta Faculty of Medicine & Dentistry. “(We) make recommendations about the diagnosis and management plan. About a quarter of patients needed to come in for further evaluation and many can be managed remotely.”

	Royal Alexandria Hospital, Edmonton, uses teleglaucoma to speed patient assessment. The wait time to see a glaucoma specialist is four to six months, Dr. Damji said. Using technicians for an initial interview, history, exam, visual field, and imaging, then sending the file to a glaucoma specialist for grading and treatment recommendations reduces access time from a mean of 88 days to 45 days and screening time from 115 minutes to 78 minutes. 

	“The whole field of mobile health is taking off with a number of different models,” Dr. Damji said. “Machine learning would be enormously helpful, but this is a very exciting time.”

	The biggest barriers to the adoption of teleglaucoma are regulatory and financial.

	“Telemedicine is still the practice of medicine, bounded in case law and medical practice acts,” said Mark Horton, OD, MD, director of the Indian Health Services/Joslin Vision Network Tele-ophthalmology Program, Phoenix, AZ. “Standards of care for telemedicine are still evolving.”

	Some state practice acts speak to telemedicine or special exemptions, but over half require full and unrestricted licensure to provide care by telemedicine, Dr. Horton noted. The American Telemedicine Association (ATA) and the Center for Telehealth & eHealth Law offer current information on specific state requirements.

	“Reimbursement depends of the payer, Medicare, Medicaid, or private insurance, and the services provided, screening, diagnosis, or management,” he said. “Assistance can be obtained from the ATA and the American Academy of Ophthalmology.”

'Teleglaucoma’ is feasible and can play a major role in blindness prevention. Telemedicine and teleglaucoma are going to be an important part of how physicians take care of patients in the United States and worldwide.

Fred Gebhart

Articles

Cataract, glaucoma collision sparks MIGS, other innovation

Match multifocal IOL to patient needs, preferences for best results

Teleglaucoma redefining role in future of blindness prevention