May 2019

NEWS

News in brief


Healthy Vision Month

May is Healthy Vision Month, sponsored by the National Eye Institute (NEI). Getting an eye exam is the first and most important suggestion that the NEI makes as part of Healthy Vision Month. Other tips ophthalmologists could give patients to encourage eye health include knowing their family eye history, protecting their eyes during work and play activities, giving eyes a rest after staring at a screen or books for long periods of time, wearing sunglasses, eating healthy foods, maintaining a healthy weight, and exercising.

Protein in vitreous could provide early biomarker test for Alzheimer’s

Scientists analyzed vitreous of 80 ocular surgery patients for proteins associated with Alzheimer’s disease, correlating them with lower cognition and suggesting that it could be a source for early disease testing.1 Levels of amyloid-ß and tau proteins in the fluid were measured and linear regression analysis tested the association between these levels and the Mini-Mental State Exam and serum apolipoprotein E allele status. Low levels of these proteins were associated with lower cognitive scores, according to the research. “These findings could help us build an accessible and minimally invasive test to determine Alzheimer’s disease risk, especially among patients with eye disease,” Lauren Wright, MD, said in a press release statement. “We noted that some of the participants who had low levels of protein biomarkers in their eye fluid already had signs of mild to moderate dementia based on their cognitive scores.” Further study is needed to compare the biomarkers that might be present in the vitreous to neurological testing.

Long-lived patterns in eye cells observed

Researchers at the National Eye Institute were able to track retinal epithelial cell patterns in healthy patients and those with retinal disease.2 Johnny Tam, PhD, said in a press release statement that studying these cells in clinic is “like looking into a black box.” This proof-of-concept study using fluorescent dye and adaptive optics, he continued, shows that clinicians can study the “unique fingerprint of the RPE, and […] monitor the tissue over time.” The researchers also designed software that recognizes RPE patterns and changes that might occur over different imaging sessions. Healthy volunteers had little change in their RPE, while a patient with Bietti crystalline dystrophy had larger, less organized RPE cells that showed major changes in the mosaic pattern over time. Dr. Tam said this imaging technique can show what is happening in this hard-to-image tissue over time.

Calcium does not increase AMD risk

While foods rich in calcium are thought to be part of a healthy diet, a study published in 2015 suggested that high levels of calcium could increase risk for age-related macular degeneration.3 More recent research by scientists at the National Eye Institute, however, suggests the opposite.4 Eating calcium or taking supplements does not increase risk for AMD; it could, in fact, have a protective effect. “Although the findings suggest that high calcium intake may be protective, the jury is still out on whether people should alter their calcium intake to prevent the onset or progression of AMD,” Emily Chew, MD, said in a press release statement. “These latest findings provide no evidence that there is a need to change the management of calcium intake for individuals who are already taking calcium for other medical indications.”

Novel hydrogel contact lens could prevent corneal melt

Corneal melts due to uncontrolled production of matrix metalloproteinases by a person’s own immune cells could be treated with a new hydrogel developed by researchers at the University of New Hampshire.5 The hydrogel deactivates these enzymes by removing zinc ions, a news release from the university explained. “Most of the current MMP inhibitors used to treat this condition work by binding to the zinc ions within the MMPs,” Kyung Jae Jeong, PhD, said in a press release statement. “However, once injected into the body, the MMP inhibitors travel through the blood stream and entire body and can cause severe side effects because they are binding with and deactivating the zinc ions in other tissue. Our hydrogel works entirely differently because it is localized, just in the eye, and deactivates MMPs by eliminating the zinc ions from the cornea. And since it would be a contact lens, if there were any issues, the patient would simply remove it.”

Light-activated adhesive gel could repair injuries without surgery

Researchers at Massachusetts Eye and Ear developed an adhesive, light-activated gel that seals corneal cuts or ulcers and encourages tissue regeneration, potentially reducing the need for surgical repair or even corneal transplantations.6 The bioadhesive, called GelCORE (gel for corneal regeneration), is naturally derived, made from a modified gelatin and “photoinitiators,” which the research paper says “can be photocrosslinked after a short-time exposure to visible light.” The hydrogel is meant to mimic corneal properties in terms of stiffness and biocompatibility. The gel has been used in rabbits so far, showing effective sealing, stromal regeneration, and re-epithelialization. “Our hope is that this biomaterial could fill in a major gap in technology available to treat corneal injuries,” Reza Dana, MD, said in a press release statement. “We set out to create a material that is clear, strongly adhesive, and permits the cornea to not only close the defect, but also to regenerate. We wanted this material to allow the cells of the cornea to mesh with the adhesive and to regenerate over time to mimic something as close to the native cornea as possible.”

Antioxidant-rich foods could lower risk of age-related cataracts

Foods high in antioxidants could lower one’s risk of age-related cataracts, according to a report.7 These foods include citrus fruits, carrots, tomatoes, and dark green vegetables. “Age-related cataracts are the leading cause of visual impairment among the elderly throughout the world, with unoperated cataracts contributing to 35 percent of all blindness,” Ming Li, PhD, said in a press release statement. “Although cataract extraction surgery is an effective method to restore vision, it will have cost society more than $5.7 billion by 2020.”

References

1. Wright LM, et al. Association of cognitive function with amyloid-ß and tau proteins in the vitreous humor. J Alzheimers Dis. 2019. Epub ahead of print.
2. Jung H, et al. Longitudinal adaptive optics fluorescence microscopy reveals cellular
mosaicism in patients. JCI Insight. 2019;4. Ecollection.
3. Kakigi CL, et al. Self-reported calcium supplementation and age-related macular degeneration. JAMA Ophthalmol. 2015;133:746–54.
4. Tisdale A, et al. The association of calcium intake with incident age-related macular degeneration Age-Related Eye Disease Study (AREDS). JAMA Ophthalmol. 2019. Epub ahead of print.
5. Lopez C, et al. Matrix metalloproteinase-deactivating contact lens for corneal melting. ACS Biomater Sci Eng. 2019;5:1195–99.
6. Shirzaei Sani E, et al. Sutureless repair of corneal injuries using naturally derived bioadhesive hydrogels. Sci Adv. 2019;5:eaav1281.
7. Jiang H, et al. Dietary vitamin and carotenoid intake and risk of age-related cataract. Am J Clin Nutr. 2019;109:43–54.
 

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