Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Novel discovery could help to improve success of corneal transplants

Novel discovery could help to improve success of corneal transplants

A team of eye specialists at The University of Nottingham has made another novel discovery that could help to improve the success of corneal transplants for patients whose sight has been affected by disease.

The research, published in the October edition of the American Journal of Ophthalmology, has shed light on a characteristic of a thin membrane called the Descemets membrane which can cause difficulties for surgeons performing the intricate Descemets membrane transplant procedure.

The study was led by Harminder Dua, Professor of Ophthalmology, and colleagues in the University’s Division of Clinical Neuroscience – the same team which was the first to discover a new layer of the cornea Pre-Descemets layer, also known as the Dua’s layer.

Professor Dua said: “This work has demonstrated a clear structural uniqueness of the pre-Descemets layer (Dua’s layer) and has also answered a puzzling surgical question on the reason why the Descemets membrane rolls in one direction, when peeled off the donor eye. This understanding will pave the way to develop strategies to unroll it during transplantation, with minimal damage to the cells it supports.”

The Descemet membrane, named after the French doctor who discovered it in the late 18th century, is found between the pre-Descemets layer (Dua’s layer) and the endothelial layer in the back of the cornea, which is responsible for pumping out excess fluid and keeping the cornea dehydrated enough to maintain clear vision.

In some diseases such as Fuchs Dystrophy or following cataract surgery, the endothelial cells and Descemet membrane are damaged, causing the cornea to become waterlogged and the vision to become clouded. Over time, the vision deteriorates and, if left untreated, can lead to loss of sight.

To cure this problem, patients may be offered one of several types of corneal transplant in which all or different parts of the damaged cornea are removed and replaced with healthy tissue from a donor.

In Descemet membrane endothelial keratoplasty (DMEK), the damaged Descemet membrane is scraped away and replaced with a donated Descemet membrane. When the membrane is separated from other layers of the cornea to prepare it for transplant it curls into a cigar-shaped roll which makes it easier to insert into the cornea via a small incision but once in place is extremely tricky to unfurl. During the manipulation of the rolled tissue, sensitive endothelial cells which coat the outside of the membrane may become damaged, reducing the success of the transplant.

In Pre-Descemet endothelial keratoplasty (PDEK), the Descemet membrane is transplanted while attached to another layer, the pre-Descemet layer – also known as Dua’s layer after it was discovered by Professor Harminder Dua in 2013 and recently endorsed as the Dua-Fine layer by the American Association of Ocular Oncologists and Pathologists. It has been found that while there is still a roll, it is not as pronounced because the pre-Descemets or Dua’s layer stabilises the Descemet layer acting as a kind of splint.

Ophthalmologists have long observed that the Descemet membrane will only roll in one direction, leaving the endothelial cells on the outside of the curl, but have been puzzled about why this occurs.

The Nottingham research has revealed for the first time that the direction of the roll is governed by the content and distribution of elastin – elastic-like fibres within the membrane.

Using 31 corneal discs earmarked for research purposes through the National Health Service’s Manchester Eye Bank, they measured the elastin content the Descemet membrane, the pre-Descemet membrane, the stroma and other sites of the cornea.

They also looked at whether treating the Descemet membrane with an enzyme that digests elastin had any effect on the rolling up of the tissue and whether removing endothelial cells had any impact on this behaviour.

The found that the pre-Descemet layer had the highest elastin content of all the tissues studied but that the elastin was evenly distributed across the tissue.

However, when they came to study the Descemet membrane they found that the elastin was concentrated in a band across its front which was causing the membrane to roll up.

The study also found that the removal of the endothelial cells from the membrane made no difference to the direction of rolling proving that it was the elastin and not the cells that were responsible for the characteristic unidirectional rolling.

Treating the Descemet membrane with the enzyme reversed the rolling effect and was associated with the degradation or disappearance of elastin in the membrane.

The results are significant as it shows that enzymes could potentially be used to weaken the rolling of the tissue, making it much easier for surgeons to successfully implant it into the cornea while reducing the potential damage to the endothelial cells which are so important in helping to regulate the fluid content of the cornea.

The latest research can be found online via the website of the American Journal of Ophthalmology.

Source:

https://www.nottingham.ac.uk/news/pressreleases/2018/october/eye-discovery-to-pave-way-for-more-successful-corneal-transplants.aspx

Tagged with:

About author

Related Articles