EW Weekly, April 8, 2016

April 8, 2016
Volume 21 , Number 13

Pfizer, Allergan call off merger deal

Pfizer (New York) and Allergan (Dublin) have mutually agreed to terminate their proposed merger, with financial analysts attributing the failed deal to the U.S. Department of the Treasury's new tax inversion rulings. Allergan's chief executive officer, Brent Saunders, told investors the company had planned for this contingency, and hinted Allergan might be interested in pursuing a deal with Valeant for its Bausch + Lomb (Bedminster, New Jersey) subsidiary.

Panocam LT granted CE mark

A phase 1/2 study evaluating RST-001, a first-in-class gene therapy application of optogenetics for the treatment of retinitis pigmentosa (RP), has dosed its first patient, developer RetroSense Therapeutics (Ann Arbor, Michigan) said in a news release.  European regulators have given the CE mark to the Panocam LT Wide-field Imaging System, a completely wireless hardware and software solution for imaging all newborns, said developer Visunex Medical Systems (Fremont, California). The Panocam is designed to detect a number of external, anterior, and posterior segment vision disorders in premature and newborn babies, and can be used for general ophthalmic imaging and eye disease inspection in children up to 6 years old.

U.S. DoD grants Vision Prosthesis Pilot Study award

The U.S. Department of Defense (DoD) has awarded Joseph F. Rizzo III, MD, grant funding as part of the Vision Prosthesis Pilot Study, a Congressionally directed medical research program. Dr. Rizzo is the director of neuro-ophthalmology at Massachusetts Eye and Ear and the David Glendenning Cogan professor of ophthalmology at Harvard Medical School, and is 1 of 3 investigators to receive funding under the study, the university said. 
In a press release, the U.S. Army Medical Research and Materiel Command commented that the program was developed to "fund projects exploring novel technologies that will contribute to a working visual prosthesis prototype for individuals who have sustained severe macular degeneration and/or traumatic eye injury."
Dr. Rizzo's team is working on the Boston Retinal Implant Project (BRIP); the project members have already developed a wireless and implantable neural prosthesis for use in the retina, but it relies on a functional optic nerve. With this award, they will develop and test a prosthesis to electrically stimulate the lateral geniculate nucleus that will allow signals to skip over the damaged optic nerve and reach visual centers in the brain, the university said.

Acucela will develop optogenetic technology

Acucela (Seattle) plans to develop human rhodopsin-based optogenetic gene therapy for the treatment of retinal degenerative disease, the company said. If approved, this genetic mutation-independent therapy, initially developed by Dr. Jasmina Cehajic-Kapetanovic and Professors Robert Lucas and Paul Bishop at University of Manchester, U.K., will use a viral vector to transduce the ON bipolar cells of the retina with human rhodopsin, a light sensitive protein normally expressed in the rod photoreceptors. Under the control of a cell specific promoter, this technology has been shown to be effective at restoring visual response in a mouse model of retinal degeneration, the company said.
Because of how rhodopsin works, the technology may become a "pan-retinitis pigmentosa" therapy that is mutation-independent, Acucela noted. 

SLET showing promise as a corneal blindness treatment

The simple limbal epithelial transplantation (SLET) may be able to efficiently treat corneal blindness caused by burns. In this technique, stem cells are harvested from the healthy eye of a patient, cut into small pieces and transplanted on the damaged cornea of the affected eye using a biodegradable membrane. Similar to dissolvable sutures, the membrane facilitates the new cells to attach and replace the original scarred surface, according to Virender Sangwan, LV Prasad Eye Institute, Hyderabad, India, and Sheila MacNeil, University of Sheffield, U.K., who developed the technique.
Long-term outcomes of 125 cases (65 adults and 60 children) treated at LV Prasad Eye Institute for limbal stem cell deficiency show an 80% success rate; patients were treated between 2010 and 2014, the group noted.


    Residual astigmatism after toric IOL implantation can be reduced by appropriate consideration of the posterior corneal astigmatism, according to Olga Reitblat, MD, and colleagues. In their retrospective comparative case series, 5 methods of toric IOL calculation were compared as follows: (1) anterior corneal astigmatism using optical low-coherence reflectometry (OLCR), (2) application of the Baylor nomogram, (3) posterior tomography combined with anterior corneal measurements using vector summation, (4) the Scheimpflug camera's true net power, and (5) total corneal refractive power. The study included 115 eyes of 92 patients. The median simulated residual astigmatism was lower when based on vector summation of anterior and posterior astigmatisms than with calculations based on anterior corneal measurements only, application of the Baylor nomogram, true net power, and total corneal refractive power readings (0.49 D versus 0.70 D, 0.60 D, 0.64 D, and 0.76 D, respectively) (P<.001). The study is published in the Journal of Cataract & Refractive Surgery.
  • One glaucoma surgery does not necessarily mean patients will undergo fellow eye surgery, according to D. Gupta and colleagues. The group conducted a post-hoc analysis of data collected from participants in the Collaborative Initial Glaucoma Treatment Study (CIGTS) who were randomized to and underwent initial trabeculectomy on their study eye, and whose fellow eye was eligible for surgical treatment. The main outcome measure was patient refusal of fellow eye surgery for glaucoma. Of 159 participants who were randomized to and underwent trabeculectomy on their study eye and had a fellow eye that was eligible for surgery, 30 (19%) refused fellow eye surgery. Eligible patients who refused fellow eye trabeculectomy did not differ significantly in visual function or local eye symptoms from those that underwent fellow eye trabeculectomy (all P>0.05). In a multivariable analysis of data, increased fellow eye preoperative intraocular pressure was associated with decreased odds (P=0.0188), study eye hypotony at 3 months postoperative was associated with increased odds (P=0.0125), and argon suture lysis procedures was associated with decreased odds (P=0.0385) of surgery refusal. The study is published online ahead of print in the American Journal of Ophthalmology.
  • Bruch's membrane opening minimum rim width (MRW) is more sensitive than disc margin rim area (DM-RA) and similar to retinal nerve fiber layer (RNFL) thickness for the identification of glaucoma in myopic eyes, according to R. Malik and colleagues. Because ruling out glaucoma in myopic eyes often poses a diagnostic challenge because of atypical optic disc morphology and visual field defects that can mimic glaucoma, the group evaluated whether neuroretinal rim assessment based on Bruch's membrane opening (BMO) rather than conventional optic disc margin (DM)-based assessment or RNFL thickness would yield a higher diagnostic accuracy. In their case controlled, cross-sectional study on myopic patients with glaucoma (n=56) and myopic normal controls (n=74), patients underwent imaging with confocal scanning laser tomography for measurement of DM-RA and with spectral domain optical coherence tomography for quantification of a BMO-based neuroretinal rim parameter, BMO-MRW, and RNFL thickness. Sensitivities at 90% specificity were 30% for DM-RA and 71% for both BMO-MRW and RNFL thickness. The partial area under the curves was higher for the BMO-MRW compared with DM-RA (P<0.001), but similar to RNFL thickness (P>0.5). Sectoral values of BMO-MRW tended to have a higher, but non-significant, partial area under the curves across all sectors compared with RNFL thickness. The study is published online ahead of print in Ophthalmology.

EYEWORLD WEEK Online is edited by Stacy Majewicz and Michelle Dalton.

EyeWorld Week Online (ISSN 1089-0319), a digital publication of the American Society of Cataract and Refractive Surgery and the American Society of Ophthalmic Administrators, is published every Friday, distributed by email, and posted live on Friday.

Medical Editors: Eric Donnenfeld, MD, chief medical editor; Rosa Braga-Mele, MD, cataract editor; Clara Chan, MD, cornea editor; Nathan Radcliffe, MD, glaucoma editor; and Vance Thompson, MD, refractive editor.

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