Sunday, October 23, 2011

New technique to revolutionize cataract surgery

Two new studies add to the growing body of evidence that a new approach to cataract surgery may be safer and more efficient than today's standard procedure of phacoemulsification.

The new approach, using a special femtosecond laser (more info here and here), is FDA-approved in the United States, but not yet widely available in the US. Research reported at the 2011 American Academy of Ophthalmology conference in Orlando by William W. Culbertson, MD, of the Bascom Palmer Eye Institute at the University of Miami School of Medicine, and by Mark Packer, MD, of Oregon Health and Sciences University, confirms several advantages of laser cataract surgery.

Dr. Culbertson's team studied how pre-treating cataracts with the femtosecond laser affected the level of ultrasound energy needed to soften the cataracts. This emulsification is performed so that the cataracts can be easily suctioned out. Surgeons want to use the lowest possible level of ultrasound energy, since in a small percentage of patients, it is associated with slower recovery of good vision after surgery and/or problems with the cornea, which is the clear outer layer of the eye. Ideally, in appropriate cases, ultrasound use would be eliminated altogether.

In Dr. Culbertson's prospective, randomized study, patients had laser cataract surgery with a femtosecond laser in one eye and the standard cataract procedure, called phacoemulsification, in the other. Laser surgery included a laser capsulotomy, which is a circular incision in the lens capsule, followed by laser lens fragmentation, then ultrasound emulsification and aspiration. Lens fragmentation involved using the laser to split the lens into sections and then soften it by etching cross-hatch patterns on its surface. Standard surgery included a manual incision, followed by ultrasound emulsification and aspiration. After cataract removal by either method, intraocular lenses were inserted into eyes to replace the natural lens and provide appropriate vision correction for each patient.

The use of ultrasound energy use was reduced by 45 percent in the laser pre-treated eyes compared with the eyes that received the standard cataract surgery procedure. Also, surgical manipulation of the eye was reduced by 45 percent in eyes that received laser pre-treatment as compared to manual standard surgery. This study involved the most common types of cataracts, those graded 1- 4. Dr. Culbertson notes that these findings may not apply to higher grade cataracts.In clinical practice, surgeons would expect safer, faster cataract surgery when laser pre-treatment is performed before cataract removal, as per Dr. Culbertson, with the combination of precision and simplification possible with the femtosecond laser represents a major advance for this surgery.

Laser lens fragmentation also demonstrates that it can protect the corneal endothelial cells. Dr. Packer and his colleagues at the Oregon Health and Sciences University in Portland, Oregon, assessed the safety of laser cataract surgery vis-a-vis loss of corneal endothelial cells, as measured after cataract surgery. Measuring endothelial cell loss (measured by a test referred to as specular microscopy) is one of the most important ways to assess the safety of new cataract surgery techniques and technology. These cells are important since they preserve the clarity of the cornea, which is important, since they do not regenerate and hence have to last a lifetime to preserve corneal clarity. Dr. Packer's study found that with laser lens fragmentation, there was no loss of endothelial cells, while eyes that received standard treatment had cell loss of one to seven percent.

Earlier studies of femtosecond laser cataract surgery have found other advantages. The laser allows the surgeon to make smaller, more precise incisions, and to perform improved capsulotomies (the initial cut in the anterior capsule of the lens to ease in removal of the cataract and insertion and secure placement of the intraocular lens (IOP) placement). This secure placement reduces the possibility of displacement of the IOL. Also, laser cataract surgery appears to improve results in patients who opt for advanced technology IOLs, plus corrective corneal incisions, to achieve good all-distance vision.

Femtosecond lasers have been used by ophthalmologists for years in refractive surgery such as LASIK, in-corneal transplants, and in other procedures. In 2009, a new type of femtosecond laser that could reach deep enough into the eye to be used in cataract removal was approved by the FDA.

Tuesday, October 18, 2011

Phase I/IIa Gene Therapy trial for Usher Syndrome type 1B approved

Oxford BioMedica plc, the leading gene-based biopharmaceutical, has announced that the US Food and Drug Administration (FDA) has approved its Investigational New Drug (IND) application for the Phase I/IIa clinical development of UshStat®, a novel gene-based treatment for Usher syndrome type1B. UshStat® was designed and developed by Oxford BioMedica using the Company's proprietary LentiVector® platform technology and is the third programme to enter clinical development under the Phase I/II ocular collaboration agreement signed with Sanofi in April 2009.

The approval of the IND follows the decision by the US Recombinant DNA Advisory Committee (RAC) to approve the UshStat® Phase I/IIa protocol in May 2011. The open label, dose escalation Phase I/IIa study will enrol up to 18 patients with Usher syndrome type 1B at the Oregon Health and Science University’s Casey Eye Institute, Portland, Oregon, USA. The study, led by Professor Richard Weleber, will evaluate three dose levels for safety, tolerability and aspects of biological activity and is expected to be initiated by the end of 2011.
Usher syndrome is the most common form of deaf-blindness, which affects approximately 30,000-50,000 patients in the US and Europe. One of the most common subtypes is Usher syndrome type1B. The disease is caused by a mutation of the gene encoding myosin VIIA (MY07A), which leads to progressive retinitis pigmentosa combined with a congenital hearing defect.

UshStat® uses theCompany's LentiVector® platform technology to deliver a corrected version of the MYO7A gene toaddress the vision loss associated with the disease. On the basis of pre-clinical data, it is anticipated that a single application of UshStat® to the retina could provide long-term or potentially permanent stabilisation of vision. There are currently no approved treatments available for Usher syndrome type1B. UshStat® has received European and US Orphan Drug Designation which brings development, regulatory and commercial benefits.

Sunday, July 31, 2011

Diabetic retinopathy is the leading cause of blindness in patients between 25 and 74 years old, according to the study appearing online in the journal General Hospital Psychiatry.

The study, as per the authors, while controling for obesity, smoking, sedentary lifestyle and HbA1c levels, found that increased risk of retinopathy in those patients who are depressed. The authors studied 2,359 patients with diabetes enrolled in the Pathways Epidemiologic Study and assessed their levels of depression using the Patient Health Questionnaire-9 (PHQ-9), a self-reported survey of depression symptoms.

Over the five-year follow-up period, 22.9 percent of the patients who had PHQ-9 scores that ranked as “major depression” developed diabetic retinopathy, compared with 19.7 percent of the patients without depression. With a five-point increase on the PHQ-9 score, patients’ risk of having diabetic retinopathy increased by up to 15 percent.

The authors conclude that changes associated with depression such as increased cortisol levels and the activity of blood-clotting factors may be linked to the development of retinopathy in patients who are depressed. They also add that multiple explanations might account for these findings, with some of them related to biological changes and others to behavioral social issues, such as decreased physical activity and poorer utilization of health care.

The question that arises is whether identifying and treating depression in patients with diabetes will make a difference to development or pregression of retinopathy.

If you wish to read the article, please click here.

Friday, July 15, 2011

Patients Undergo Embryonic Stem Cell Transplantation Treatment for Stargardt's Disease and Macular Degeneration

Advanced Cell Technology, Inc., a leading company in the field of regenerative medicine, has announced that two patients have been implanted with retinal pigment epithelial (RPE) cells derived from human embryonic stem cells (hESCs) in each of its two Phase 1/2 clinical trials for Stargardt's macular dystrophy and dry age-related macular degeneration (AMD).

The patients were treated on July 12, 2011, at the David Geffen School of Medicine at UCLA's Jules Stein Eye Institute in Los Angeles, USA. Both patients successfully underwent the outpatient transplantation surgeries and are said to be recovering uneventfully.

One patient in each clinical trial, the Stargardt's trial and the dry AMD trial, underwent surgical transplantation of a small dose (50,000 cells) of fully-differentiated RPE cells derived from human embryonic stem cells. The patients appear to have tolerated the surgical procedures well.

Regarding the clinical trial:

Both the Stargardt's trial and the dry AMD trial will enroll 12 patients each, with cohorts of three patients each in an ascending dosage format. Both trials are prospective, open-label studies designed to determine the safety and tolerability of hESC-derived RPE cells following sub-retinal transplantation into patients with Stargardt's and dry AMD at 12 months, the studies' primary endpoint.

This is the first step in the clinical trial, which will potentially define the dose required to help treat the condition. If the trial succeeds, it opens doors to a potentially significant and new therapeutic approach to treating Stargardt's disease and AMD.

The primary objective of these Phase 1/2 studies is to assess the safety and tolerability of these stem cell-derived transplants. The patients will be carefully monitored over the course of the trials, to observe and report for any untoward and adverse event that may happen.

To know more of this trial, please click here.

About hESC-RPE Cells

RPE cells are highly specialized tissue located between the choroid and the retina. RPE cells support, protect and provide nutrition for the light-sensitive photoreceptors. Human embryonic stem cells differentiate into any cell type, including RPE cells, and have a similar expression of RPE-specific genes compared to human RPE cells and demonstrate the full transition from the hESC state.

About Stargardt's macular dystrophy:

Stargardt's macular dystrophy is one of the most common forms of macular degeneration in the world. Stargardt's causes progressive vision loss, usually starting between 10 to 20 years of age. Eventually, blindness results from photoreceptor loss associated with degeneration in the pigmented layer of the retina, called the retinal pigment epithelium or RPE cell layer.

About Age-related Macular Degeneration:

Degenerative diseases of the retina are among the most common causes of untreatable blindness in the world. Approximately 10% of people ages 66 to 74 will have symptoms of macular degeneration, the vast majority of them suffering from the "dry" form of AMD - which is currently untreatable. The prevalence increases to 30% in patients 75 to 85 years of age.

Dry AMD, the most common form of macular degeneration, Stargardt's and other forms of atrophy-related macular degeneration are untreatable at this time, and need effective therapies for treatment of these common forms of blindness.

Disease progression of both Stargardt's and dry AMD includes thinning of the layer of RPE cells in the patient's macula, the central portion of the retina and the anatomic location of central vision. When RPE cells die, the macular photoreceptors are lost, leading to loss of central vision. This approach focuses on treating these conditions by transplanting RPE cells in the patient's eyes before the RPE population is lost.

Source

Tuesday, July 12, 2011

Market for Age-related Macular Degeneration and Diabetic Retinopathy Drugs Will Reach $5084m by 2014

A new report by visiongain, a London-based business information provider, predicts that the market for age-related macular degeneration (AMD) and diabetic retinopathy (DR) drugs will reach $5084m by 2014. This will make retinal diseases the most lucrative sector of the ophthalmic drugs market, overtaking the glaucoma sector.

The AMD and DR market generated $3173m in 2010, according to Macular Degeneration (AMD) and Diabetic Retinopathy (DR): World Drug Market 2011-2021, published in July 2011.

AMD and DR are retinal disorders that can lead to blindness. Between them, they have been the cause for over 13% of all blindness cases in the world, according to a most recent WHO assessment. Both AMD and DR will become more widespread in the coming decades, as the world's population ages and the global diabetes epidemic continues.

Genentech's development of Lucentis (ranibizumab) made the 'wet' form of AMD effectively treatable for the first time. The success of Lucentis spurred investment in R&D for retinal diseases. In 2011, new products for wet AMD, as well as treatments for the 'dry' form of AMD, and for DR and diabetic macular oedema, are all nearing approval.

August will see the approval of Eylea (aflibercept), Regeneron Pharmaceuticals' new AMD treatment. This will be the most important new product in the AMD and DR sector since the launch of Lucentis.

Visiongain's research suggests that scientific study of retinal diseases will yield more important insights in the next ten years. While Lucentis and Eylea target vascular endothelial growth factor (VEGF), products with new targets will gain importance as monotherapies and in combination with VEGF inhibitors.

Visiongain predicts that the AMD and DR market will grow steadily to 2021, with treatments for dry AMD and DR answering the serious unmet needs in the sector.

Source

First VIDION® ANV® Therapy System Utilization in Switzerland for the Treatment of Neovascular Age-Related Macular Degeneration

NeoVista, Inc. has announced the first commercial utilization of Epimacular Brachytherapy in Switzerland. Epimacular Brachytherapy is performed using the VIDION (R) ANV Therapy system and is being offered as an adjunct therapy to anti-VEGF injections for the treatment of neovascular or wet age-related macular degeneration.

Professor Dr. Marc D. de Smet, Professor and Head of the Retina Unit at the Montchoisi Clinic in Lausanne feels Epimacular Brachytherapy with VIDION® is a surgical procedure that is technically feasible in good hands, with minimal to no risks and reduces the burden of follow up and retreatments.

As per the company, NeoVista’s phase 2 clinical study results continue to highlight the potential benefits of utilizing radiation with anti-VEGF therapy in treating wet AMD – especially on smaller classic lesions and patients with pigment epithelial detachments. They believe that their treatment approach, Epimacular Brachytherapy, greatly reduces the number of anti-VEGF injections, while maintaining visual acuity – especially in those lesion subtypes that typically require a large number of injections."

NeoVista’s Phase 3 study, CABERNET, is about to conclude the required 2 year patient follow-up. The initial data from this study is scheduled to be presented during the upcoming AAO Retina Sub-Specialty Meeting in Orlando, Florida, October 21. The NeoVista approach to treating wet AMD delivers a focused and fixed dose of strontium 90 beta radiation directly to the back of the eye, without damaging the adjacent healthy retinal vasculature. Importantly for patients, the systemic exposure to radiation is easily tolerated and the energy is delivered in a highly controlled manner to a local area. The effective dose from this one-time treatment is less than that from a typical chest x-ray to the entire body.

Source

Some other articles on Epimacular Brachytherapy can be read here, here, here and here.

Tuesday, July 5, 2011

Sightseeing for blind people

By Jon Henley  /  The Guardian, London (click here for the original article)

So we’re standing in the street outside the brothel — or what used to be the brothel — in Pompeii. The one with the rude frescoes on the walls showing ancient Roman punters exactly what they could expect for their sesterces.

There are 20 of us, or thereabouts, and before we go in the man in the white cheesecloth shirt and the floppy sun hat would like a word.

“Ladies and gentlemen, our sighted guides,” says Amar Latif. “I’d just like to remind you of my words at the beginning of this holiday. You are not carers; you are fellow travelers, companions. And one of the most valuable things you can do is to describe in loving detail whatever you might see before you that is of visual interest. Here’s your chance.”

And so it is that Maggie Heraty, a jolly humanitarian logistics expert more used to organizing emergency relief operations in Liberia or Haiti, finds herself explaining to Jenny Tween, who works at the BBC and has optic atrophy, meaning she has been partially sighted since she was two, that here we have: “a gentleman, reclining. With a naked lady squatting on top.”

While over here, Heraty continues, undaunted by Tween’s snorts, we can see (or not, of course) “the doggy position. And just along from that, the lady’s on top of the gentleman, again. But facing his feet this time. Hmmm.” She pauses. “Sorry, Jenny. Just trying to work out the mechanics of that one. I don’t think I’ve ever tried it.”

It’s not, obviously, that these people spend their holiday discussing the sex lives of the Ancients.

But nor are they your regular holidaymakers. Half of them, for a start, are blind or visually impaired. The other half are fully sighted. The former have paid a bit more than they might do for a standard package holiday to come on this week-long break in Sorrento, southern Italy, including flights, transfers, half-board in a four-star hotel with pool, a cookery lesson and excursions to Pompeii, Capri and Positano.

The latter have paid quite a bit less. In exchange, every day they will take a different visually impaired traveler by the arm (not literally, there’s nothing a blind or partially sighted person — or “VI,” as they’re more familiarly known — loathes more than being patronized) and act as their guide. Show them, as it were, the sights.

Sighted travelers help VIs with obvious obstacles: curbs, low arches and doorways, busy roads, flights of stairs (“Step down. One more to go. That’s the bottom.”) They explain where the food is on a plate (“Chicken at three o’clock, peas at six”). And once in a while, they get to describe in loving detail the wall paintings in the Pompeii brothel.

It’s not hard. In fact it’s fun. You learn a lot. “You get to do things you wouldn’t normally do,” says Wendy Coley from Loughborough, England, a sighted veteran of many such expeditions. “Once, in China, they got to touch the terra-cotta warriors. Imagine. And the act of describing what you see ... You take in far more, somehow; see things in a very different way. It may sound silly, but going on holiday with blind people opens your eyes.”

It does. I tried it at Gatwick with Latif, the 36-year-old Glasgow-born entrepreneur who set up this strangely inspiring business seven years ago. Latif has been without 95 percent of his sight since his first year at university, thanks to an incurable eye condition called retinitis pigmentosa. He founded Traveleyes, as the company is called, because “no one was doing the kind of holiday I wanted to go on,” and as far as he knows it’s the only one of its kind in the world.

An airport, you very quickly realize, is not a great place to be a VI. Inexpertly piloted baggage trolleys, beeping electric buggies, non-speaking departure boards, too many people in too much of a hurry; a nightmare. And if you ask for help, Latif says, they “put you in a wheelchair. Blind people go mental. It’s a liability avoidance thing, but it’s so humiliating. Most of us are highly independent, and extremely competent. We don’t need wheelchairs.”

Technology has made life easier in recent years, he concedes: “Piece of piss, to be honest, compared to what it was.” His mobile phone responds to vocal commands (assuming it understands his accent, which isn’t always), and speaks to him when he taps it. Screen reading software means blind and visually impaired people can use applications from Gmail to Excel, and even get the newspaper read to them online.

But navigating a crowded airport is another matter. Latif has his white cane, essential when he has to “go freestyle.” But it’s just more comfortable, sometimes, to be led. So what you do is, you stand beside and just slightly in front of the VI you’re leading, and offer them your elbow. They grasp it lightly (“Clicking on,” Latif calls it), and off you go. A tad slower than you otherwise might, but not much.

It’s that leading arm that transmits the messages. You have to talk, too, obviously, but it’s mainly just natural, friendly chat, interspersed with the odd alert (“Step up. Escalator coming.) Blind people feel in control when they’re holding your elbow, and will let go if they get anxious (or so says How to be a Sighted Traveler, the leaflet Traveleyes sends to its sighted customers).

You notice, too, that blind people pick up an awful lot more than you do through their other senses. “I can hear the hand-dryers,” says Latif. “Is that the gents, by any chance? Might just nip in.” Or, to a slightly nonplussed security man, “I can smell fruit. Exotic? Strawberries?” A fresh stick of Juicy Fruit gum, the guard admits.

You have to be a bit careful what you say, but you soon learn that an inadvertent “Did you see that?” or “Look, over there!” is not going to upset anyone.

Latif’s beaming presence helps hold the whole thing together. He’s a quite remarkable man; much in demand as a motivational speaker, and you can see why. A maths and finance graduate, he worked as a management accountant for eight years before striking out on his own, overcoming untold obstacles to launch a highly successful company, win a fistful of business and disability awards, and gladhand presidents and prime ministers.

“This holiday,” he announces to all on the bus from Naples airport to Sorrento, “is all about enjoying things on an equal basis. So if you’re blind, don’t worry, so am I. And if you’re sighted, don’t be so bloody clever.”

When it comes to holidays, beyond imposing again on long-suffering friends and relatives, the blind or visually impaired have shockingly few options. A charity called Vitalise runs holidays for people with a range of disabilities, but that’s about it. Not just in Britain, either: 30 percent of Traveleyes’ VIs come from abroad, mainly North America, Australia and New Zealand.

On the way back through town, stopping to wonder at the heft of a tomato and inhale an olive oil in the market, we’re drawn into a shop selling limoncello, the lemon-based liqueur of the Gulf of Naples. Sensing a celebratory mood, the proprietor turns up the music. “Here we say: we have a lemon, we have a girl, we have a party!” he proclaims. And to Dean Martin belting out Volare, then That’s Amore, everyone — unembarrassed — dances.

For sighted travelers, the motivation for this kind of holiday is maybe more complex. There are two sighted couples on this trip, but many are single. Several have tried singles holidays, without enjoying them: too full of “people out for themselves”; you end up “feeling lonelier when you leave than when you arrived.”
Irene Sylvester, from Wakefield in West Yorkshire, is newly retired. “I was looking for something I could do on my own,” she says, “but that wouldn’t make me feel I was on my own.” Jayn Bond, an HR and employment law specialist from Cambridge, wanted “a holiday that wouldn’t make me feel lonely, and where I could contribute.”

Others have less exalted reasons: Glyn Evans, a signalman from Rotherham, has been on a dozen Traveleyes holidays. He loves “the laughs. They’re great people.”

He’s on to something here, Latif, that’s about more than offering holidays for blind people. He knew the idea would work as soon as he tried it out for himself, with a student who used to read his textbooks for him at university: both of them had a ball. The first organized holiday, to a farmhouse in Andalucia, Spain, in 2004, was a roaring success; since then, Traveleyes has grown by 50 percent each year. And more than 60 percent of its business is repeat, from people who’ve been before.

Are there never problems? “You might think,” he says, “that the cheap holiday thing could attract the wrong people. We do a criminal records check and an employer’s check; it’s slightly tricky — you’re not employing people, but you do have to be aware that they’re dealing with vulnerable adults. But honestly, there’s never been a problem.”

Destinations are chosen carefully; there has to be plenty of opportunity for non-visual exploration. But blind people also love sightseeing, Latif insists. “The fact I can’t see the sights only heightens my curiosity,” he says.
It’s not uncommon, Latif says, for guests staying in the same hotel to ask whether they can join a Traveleyes group, “because they’ve seen the time we’re having, the atmosphere.” So what actually is happening here? A married couple, Dick and Lizzie Bulkely, turned away at the last minute by another firm because of Lizzie’s advancing glaucoma, put their finger on it.

“I’m really interested in how these groups work and get on,” says Dick, a retired clinical psychologist. “The constant negotiating, the compromise, the concern. There are real, important people skills going on here, all the time. I really like it. And you don’t come across it very often.”