STEM CELLS REGENERATE HUMAN LENS AFTER CATARACT SURGERY, RESTORING VISION
Researchers at the University of California, San Diego School of Medicine and Shiley Eye Institute, with colleagues in China, have developed a regenerative medicine approach to remove congenital cataracts in infants, permitting remaining stem cells to regrow functional lenses, according to a UC San Diego news release and a study published in Nature.1
The investigators designed a surgical method of cataract removal that relies on the regenerative potential of endogenous stem cells. Unlike other stem cell approaches that involve creating stem cells in the lab and introducing them back into the patient, with potential hurdles such as pathogen transmission and immune rejection, endogenous stem cells are naturally in place at the site of the injury or problem. In the human eye, lens epithelial stem cells (LECs) generate replacement lens cells throughout a person’s life, although production declines with age, the news release said.
Current cataract surgery largely removes LECs within the lens; the lingering cells generate disorganized regrowth in infants and no useful vision. “An ultimate goal of stem cell research is to turn on the regenerative potential of one’s own stem cells for tissue and organ repair and disease therapy,” study author Kang Zhang, MD, PhD, said in the news release.
After confirming the regenerative potential of LECs in animal models, the researchers developed a novel minimally invasive surgery method that preserves the integrity of the lens capsule and that stimulates LECs to grow and form a new lens that can provide vision. “Our method differs conceptually from current practice, as it preserves endogenous LECs and their natural environment maximally, and regenerates lenses with visual function,” the study authors wrote.
In tests in animals with cataracts and a subsequent small human trial, the investigators found that the surgical technique allowed preexisting LECs to regenerate functional lenses. The human trial included 12 infants under the age of 2 years who were treated with the new method and 25 similar infants receiving current standard surgical care; the latter control group experienced a higher incidence of postoperative inflammation, early-onset ocular hypertension, and increased lens clouding.
The investigators reported fewer complications and faster healing among the 12 infants who underwent the new procedure. Further, after 3 months, a clear, regenerated biconvex lens was observed in all of the patients’ eyes.
Dr. Zhang and colleagues are now looking to expand their work to treating age-related cataracts, the news release said. “We believe that our new approach will result in a paradigm shift in cataract surgery and may offer patients a safer and better treatment option in the future,” he said.
1. Lin H, Ouyang H, Zhu J, et al. Lens regeneration using endogenous stem cells with gain of visual function [published online ahead of print March 9, 2016]. Nature. doi:10.1038/nature17181.
Zika Virus-Related Microcephaly Associated With Vision-Threatening Abnormalities
Infants with microcephaly associated with presumed intrauterine Zika virus infection may develop vision-threatening abnormalities, according to a study in JAMA Ophthalmology.1
Bruno de Paula Freitas, MD, of Hospital Geral Roberto Santos, Brazil, and colleagues conducted a study to evaluate the ocular findings in infants with microcephaly associated with presumed intrauterine Zika virus infection. Twenty-nine infants with microcephaly with a presumed diagnosis of congenital Zika virus were recruited through an active search and referrals from other hospitals and health units.
All infants and mothers underwent systemic and ophthalmic examinations from December 1 through December 21, 2015. Anterior segment, retinal, choroidal, and optic nerve abnormalities were documented using a widefield digital imaging system. The differential diagnosis included toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, syphilis, and human immunodeficiency virus, which were ruled out through serologic and clinical examination.
Twenty-three of the 29 mothers (79.3%) reported suspected Zika virus infection signs and symptoms during pregnancy. Among 29 infants (58 eyes), ocular abnormalities were present in 17 eyes (29.3%) of 10 children (34.5%). Bilateral findings were seen in seven of 10 patients presenting with ocular lesions, the most common of which were focal pigment mottling of the retina and chorioretinal atrophy in 11 of the 17 eyes with abnormalities (64.7%), followed by optic nerve abnormalities in eight eyes (47.1%), bilateral iris coloboma in one patient (11.8%), and lens subluxation in one eye (5.9%).
1. de Paula Freitas B, de Oliveira Dias JR, Prazeres J, et al. Ocular findings in infants with microcephaly associated with presumed Zika virus congenital infection in Salvador, Brazil [published online ahead of print February 9, 2016]. JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2016.0267.
Bilateral Laser Refractive Surgery Most Frequent in Young UK Women
In the United Kingdom, bilateral laser refractive surgery may be most frequent among young and active women with higher incomes, according to a study published in the Journal of Cataract and Refractive Surgery.1
Phillippa M. Cumberland, MSc, of University College London, and colleagues conducted a cross-sectional epidemiologic study to evaluate the frequency and distribution of laser refractive surgery in the United Kingdom by sociodemographic factors and outcomes of social participation and well-being. Data were collected on sociodemographic factors and medical history; self-reporting on eyes and vision included reason for wearing optical correction, history of eye diseases, and treatment received, including laser refractive surgery. Mean spherical equivalent was used to categorize individuals as myopic or hyperopic.
Between 2009 and 2010, 117,281 patients recruited by UK Biobank underwent ophthalmic assessment including autorefraction. Of those with refractive error within a range eligible for laser refractive surgery (n = 60,352), 1,892 (3.1%) reported having bilateral refractive surgery and 549 (0.9%) unilateral surgery. Frequency of bilateral surgery decreased with increasing age and was higher in women. Frequency did not vary with educational attainment or accommodation status but increased with income among working adults. Participation in social activities was more common among those who underwent surgery. Other eye conditions were reported by 28% of those reporting refractive surgery compared with 11% of those eligible for treatment but not reporting surgery.
1. Cumberland PM, Chianca A, Rahi JF; for the UK Biobank Eyes & Vision Consortium. Laser refractive surgery in the UK Biobank study. J Cataract Refract Surg. 2015;41(11):2466-2475.
Smart Vision Labs Receives CE Mark for SVOne Autorefractors
Smart Vision Labs has received the CE Mark for the the SVOne handheld Hartmann-Shack wavefront aberrometer, according to a company news release. SVOne accurately measures objective refractive error in children and adults and, in clinical studies, has been shown to be as accurate as legacy desktop autorefractor units, the news release said.
Teva Receives Approval for Allergan Generics Acquisition
Teva Pharmaceutical Industries received regulatory approval from the European Commission for its acquisition of Allergan’s global generics business, according to a news release.
Teva has agreed to the divestment of certain overlapping molecules in 24 European countries, other than the United Kingdom, Ireland, and Iceland. In the United Kingdom and Ireland, Teva will divest a majority of the current Allergan generic business. As required by the European Commission, the divested business will be capable of manufacturing and marketing generic medicines. The remainder of the Allergan generics UK/Ireland business will be integrated with Teva’s operations in line with the global transaction. In Iceland, Teva will divest its generic business and retain the Allergan generics business.
EMA Launches PRIME Scheme for Priority Medicines
The European Medicines Agency (EMA) launched the Priority Medicines (PRIME) scheme to strengthen support for medicines that target unmet clinical needs, according to a news release. The PRIME scheme focuses on medicines that may offer a major therapeutic advantage over existing treatments or may benefit patients with no treatment options. These medicines are considered priority medicines in the European Union.
Through PRIME, the EMA offers early, proactive, and enhanced support to medicine developers to optimize the generation of robust data on a medicine’s benefits and risks and enable accelerated assessment of medicine applications. PRIME aims to strengthen clinical trial designs to facilitate the generation of high-quality data for the evaluation of an application for marketing authorization. Early dialogue and scientific advice also ensure that patients participating in trials are likely to provide the necessary data for an application for marketing authorization and make the best use of limited resources.
For a medicine to be accepted for PRIME, its potential to benefit patients with unmet clinical needs must be shown based on early clinical data. Once a candidate medicine has been selected for PRIME, the EMA will do the following:
- Appoint a rapporteur from its Committee for Medicinal Products for Human Use or from the Committee on Advanced Therapies to provide continuous support and help build knowledge ahead of a marketing authorization;
- Organize a meeting with the rapporteur and a multidisciplinary group of experts from relevant EMA scientific committees and working parties and provide guidance of the overall development plan and regulatory strategy;
- Assign a dedicated EMA contact point;
- Provide scientific advice at key development milestones, involving additional stakeholders such as health technology assessment bodies, to facilitate access to the medicine; and
- Confirm potential for accelerated assessment at the time of an application for marketing authorization.
PRIME is open to all companies on the basis of preliminary clinical evidence. Micro, small, and medium-sized enterprises and applicants from the academic sector can apply earlier on the basis of compelling nonclinical data and tolerability data from initial clinical trials, the news release said. n
– Compiled by Steve Daily, Executive Editor, News;
and Callan Navitsky, Senior Editor
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