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ARVO HIGHLIGHTS

Over 11,000 delegates gathered in Florida for the 2014 Meeting of the Association for Research in Vision and Ophthalmology.

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Progress in gene therapy for retinal disease

Researchers from Oxford University reported promising clinical results in a gene therapy trial of choroideraemia. Six patients received gene therapy via an adeno-associated viral vector. Six months after surgery, visual acuity improved by two lines and four lines in two patients in whose visual acuity was less than 20/30 at baseline, which was sustained at one year. Visual acuity returned to within one line of baseline in the other four patients. Despite undergoing foveal detachment, there was improvement in retinal sensitivity in the treated eyes compared to the control eyes one year after gene therapy. Improvements in retinal sensitivity correlated to the total dose of vector administered. Treated eyes did show some mild progression of cataract, but showed no significant retinal thinning. The researchers believe these results show the potential of gene replacement therapy when applied before the onset of foveal thinning, and validate the concept of subretinal gene delivery.

In a separate study, US researchers reported promising animal data of gene therapy to stop the progression of RPGR gene-associated retinitis pigmentosa. An AAV-mediated gene transfer of RPGR 1-ORF15 cDNA delivered at early, mid and late stages produced stable and long-term photoreceptor rescue for up to 90 weeks.

 

Urine test for RP gene

A urine test for genes associated with retinitis pigmentosa (RP) would be a boon for clinicians and their patients. Investigators at Bascom Palmer Eye Institute, University of Miami, determined that urinary dolichol profiles identified in patients with autosomal recessive RP might serve as quantitative biomarkers for dehydrodolichol diphosphate synthase, a key enzyme in dolichol biosynthesis. A study of patients including those with autosomal recessive RP, carriers of the DHDDS gene, and controls indicated that urine and serum testing could reliably determine if the gene was the disease causing form. They conclude that the test could be readily adapted for clinical use.

 

New nystagmus treatment

A new class of drugs could make a big difference in the treatment of nystagmus.

The discovery was entirely serendipitous. A patient with nystagmus reported seeing better after accidentally spraying a nerve agent in his right eye. US researchers report that applying various concentrations of the agent in a canine model of the disease produced significant decreases in the nystagmus symptoms, along with reduced intraocular pressure.

 

AMD treat and extend

One of the great debates among retina specialists is which anti-VEGF regime benefits patients the most. US and European researchers used a “treat and extend” approach, in which the frequency of office visits and injections were tailored to each patient’s individual response to therapy. They followed 185 patients over a three-and-a-half-year period. Using this approach, the average number of visits and injections was reduced from 12 to 8.3 times per year.

They observed that, contrary to previous clinical trial findings, monthly injections to counteract age-related macular degeneration (AMD) may not be necessary in all patients. Follow-up analyses showed better long-term outcomes in patients with Type I neovascularisation, who appeared less likely to develop geographic atrophy.

 

New reversible glue

An innovative thermoresponsive reversible adhesive offers a promising new technique for treating ocular trauma in the emergency setting. When pNIPAM )Poly(N-isopropylacrylamide), is applied to the eye, it warms up, sealing the wound while the patient is transported. Once at the hospital, surgeons would need only apply a cold saline solution to the eye, after which the glue can be removed easily with minimal discomfort.

 

New direction in glaucoma

An observation that pressure from the fluid surrounding the brain plays a role in maintaining proper eye function could open a new direction for treating glaucoma. Australian researchers presented research based on a rat model indicating that elevating intracranial pressure can counterbalance elevated pressure in the eye, preventing the optic nerve from bending backward. Rats with higher fluid pressure from the brain maintained their ability to respond to light better than rats with lower pressure. They note that these findings give a potential clue as to why some patients with normal intraocular pressure go on to develop glaucoma, while others with elevated intraocular pressure do not.

 

Making stem cells from eyes, eyes from stem cells

Two groups report the development of methods to convert non-embryonic stem cells into eye cells that could further research in ophthalmological regenerative medicine. One group of researchers described a technique for using induced pluripotent stem cells derived from human Tenon’s capsule fibroblasts to express retinal progenitor cell-related genes with the capacity to directly differentiate into retinal neurons in vitro. A second group describe a method of introducing stem cells to adding human insulin-like growth factor to human embryonic stem cells and induced pluripotent stem cells, and then forming three-dimensional retinal tissue.

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