Friday, July 15, 2011

Abstract: Chronic (neuropathic) corneal pain and blepharospasm

Chronic (neuropathic) corneal pain and blepharospasm: five case reports.
Pain.
Pain and focal dystonias have been associated with chronic pain conditions such as complex regional pain syndrome. Corneal pain, frequently known as "dry eye", may be a neuropathic pain condition with abnormalities of the nerve plexus. Here we present 5 case histories of patients with defined corneal pain (with associated neuropathic features) and objective measures of changes in the nerve plexus and associated blepharospasm. A putative relationship between pain and blepharospasm suggests potential involvement of the basal ganglia in both these conditions.


2011 Jul 11. [Epub ahead of print]
Borsook D, Rosenthal P.
Center for Pain and the Brain, McLean Hospital, Massachusetts General Hospital, and Children's Hospital of Boston, Harvard Medical School, Boston, MA, USA.

Wednesday, July 13, 2011

Abstract: Extended cyclosporine delivery by silicone-hydrogel contact lenses

Extended cyclosporine delivery by silicone-hydrogel contact lenses.

Cyclosporine A (CyA) is effective in treating chronic dry eyes and contact lens mediated dry eyes. CyA is delivered through eye drops of an oil-in-water emulsion, which has a small residence time in the eyes, leading to low bioavailability. Here we explore delivery of CyA from contact lenses to provide controlled and extended drug delivery with an increased bioavailability due to enhanced ocular residence time. Loading and release profiles of CyA from commercial contact lenses are presented to show that increase 1-DAY ACUVUE® releases CyA for about a day and extended wear silicone hydrogel (SiH) lenses release CyA for about 2-weeks. The longer duration from SiH lenses compared to the 1-DAY ACUVUE®lens is due to larger partition coefficients in the gel. A novel approach is presented for increasing release duration from the SiH lenses to the desired 1-month through incorporation of Vitamin E. The results show that Vitamin E loaded lenses can provide CyA release within the therapeutic window for a period of about a month. This pilot study demonstrates the promising potential of delivering CyA from contact lens for treatment of chromic dry eyes and contact lens mediated dry eyes.

J Control Release. 2011 Jul 2. [Epub ahead of print]
Peng CC, Chauhan A.

Tuesday, July 12, 2011

Device news: Lipiflow gets FDA approval

Morrisville company gets clearance to sell dry eye product

MORRISVILLE, N.C. — A Morrisville-based company has gotten clearance from the U.S. Food and Drug Administration to market and sell a technology used to help people with dry eyes.

TearScience announced Monday that it has received FDA clearance for its LipiFlow Thermal Pulsation System, which is designed for the treatment of meibomian gland dysfunction (MGD), also known as evaporative dry eye.

The clearance enables the privately-held medical device company to market and sell the system to eye care physicians in the U.S.

LipiFlow will be available immediately, but on a limited basis in the U.S. through the end of 2011.

LipiFlow removes meibomian gland obstructions by applying directed energy to a patient’s eyelid during a 12-minute in-office treatment. MGD may well be the leading cause of dry eye disease throughout the world.

“At last, physicians will have the necessary tools they need to break the cycle of frustration for many dry eye patients,” said Dr. Alan Carlson, chief of the corneal, external disease, and refractive surgery service at the Duke Eye Center in Durham. “Now, with FDA clearance to market the LipiFlow, TearScience provides a new, innovative alternative treatment that delivers effective relief for many patients who desperately need it.”

Of the more than 100 million dry eye sufferers worldwide, approximately 65 percent have evaporative dry eye.

Common symptoms of the disease include eye irritation, dryness, redness, tiredness and visual disturbances. TearScience’s integrated, in-office system addresses a root cause of evaporative dry eye, the obstructed glands.

TearScience gained FDA clearance by demonstrating the safety and effectiveness of LipiFlow through a U.S.-based, nine-center randomized controlled clinical trial for the treatment of evaporative dry eye.

The FDA has approved 20 new drugs so far this year, just one short of the total for all of 2010, according to a top agency official last week. The pace likely puts the FDA on track to approve more new types of drugs in 2011 than the previous few years.

TearScience’s technology, however, does not fall into this list.

FDA's drug approval figures released on Thursday involve only drugs or biologics – which are made from living cells – that are considered new types of products. They don't include approvals granted for new formulations, systems, or new uses of existing drugs as well as vaccines.

“The LipiFlow system is a very unique, very exciting system,” said Dr. Stephen Lane, of Associated Eye Care of Stillwater, Minn.

TearScience will sell its LipiFlow and LipiView Ocular Surface Interferometer devices as a system for eye care practices.

Tim Willis, chief executive officer and co-founder of TearScience, said Monday marks an important day for ophthalmologists in the U.S.

“This is a paradigm shift in addressing the root cause of the disease and not just the symptoms,” Willis said. “Today, the patients win."

Abstract: Eye Platelet Rich Plasma (E-PRP)

The Role of "Eye Platelet Rich Plasma" (E-Prp) for Wound Healing in Ophthalmology.

Blood derived products have demonstrated their capacity to enhance healing and stimulate the regeneration of different tissues and this enhancing effect is attributed to the growth factors and bioactive proteins that are synthesized and present in blood. Eye platelet rich plasma (E-PRP) provides higher concentration of essential growth factors and cell adhesion molecules by concentrating platelets in a small volume of plasma as compared with autologous serum, the latter being used widely in ophthalmology for epithelial wound healing of the cornea for the last two decades. These growth factors and cell adhesion molecules have a major role in wound healing and enhance the physiological process at the site of the injury/surgery via eye drops or clot. E-PRP has been used more recently, and has achieved successful outcomes in peer-review articles in the treatment of dormant ulcers (epithelial defects of the cornea that fail to heal), moderate to severe dry eye syndrome, ocular surface syndrome post Laser In Situ Keratomileusis (LASIK), and for surface reconstruction after corneal perforation associated with amniotic membrane transplantation. Preparation of E-PRP in the two available formulations, eyedrops and clot, is inexpensive and easy although it requires following strict sterility conditions using sterile and disposable materials and operating inside a laminar flow hood. No serious adverse effects have been described with the use of these products, and it is generally well tolerated. In summary, Platelet enriched plasma in the form obtained in ophthalmology, E-PRP, is a reliable and effective therapeutic tool to enhance epithelial wound healing in ocular surface disease.

Curr Pharm Biotechnol. 2011 Jul 8. [Epub ahead of print]
AliĆ³ JL, Arnalich-Montiel F, Rodriguez AE.
Source
Department of Cornea and Refractive Surgery, VISSUM Corporation, Madrid, Spain. arnalich@hotmail.com.