The latest ophthalmology research – in brief
Phoebe Harkin | | Quick Read
- Statins are commonly prescribed for lowering cholesterol – but new research may signal an alternative use. A recent study by Brigham and Women’s Hospital has found that long-term statin use could strengthen the neuroprotective mechanisms that prevent degeneration of the optic nerve, effectively lowering glaucoma risk. Researchers monitored 136,782 patients – 886 of whom had primary open-angle glaucoma – over a 15-year period. They discovered that participants who used statins for five years or more experienced a 21 percent lower chance of glaucoma than those who had never used statins. Interestingly, every 20 mg/dL increase in cholesterol level was associated with a 7 percent increase in glaucoma risk. “As high cholesterol and statin use have been associated with other neurodegenerative diseases, the interrelationship between cholesterol, glaucoma and these outcomes is also fertile ground for further scientific inquiry,” commented the paper’s lead author, Jae Hee Kang, an Associate Professor of Medicine at Brigham and Women’s Hospital (1).
- Like any optical element, the human lens contains aberrations, which can degrade the images received by the retina and affect the images seen by clinicians during eye examinations. Attempts to compensate for longitudinal chromatic aberrations (LCA) have so far been based on calculations for the “average” eye, but the results are variable. But not for long. Researchers at the University of Washington have found a way to accommodate aberrations. Using a combination of filters, lens distances and multiple color illumination, the team has developed a new customizable imaging system that cancels out a person’s unique chromatic optical aberrations, allowing for a more accurate assessment of vision and eye health. The team incorporated a new optical assembly with conventional adaptive optics instruments to produce individually tailored high-resolution, multiple-wavelength pictures of the smallest cone photoreceptors in the eye, measuring just 2 microns across. The method successfully overcame inconsistencies in previous estimates of the human eye’s native LCA related to depth of focus, monochromatic aberration and wavelength-dependent light interactions with retinal tissue. The team hope the breakthrough will lead to new insights on visual halos, glare and color perception, as well as the effect of aging on the eye.
- A team of University of Pennsylvania engineers has designed the world’s first artificial human eye-on-a-chip – complete with blinking lid. The chip acts as an animal-free drug testing platform, made of a porous, 3D printed scaffold covered in specialized corneal and conjunctival tissue. The lid – a mechanized gelatin slab – spreads artificial tear secretions with each blink. The design was used to study the impact of lubricin, a promising treatment for dry eye disease, on the ocular surface. By comparing the results of three models (a healthy eye, an eye with dry eye, and an eye with dry eye plus lubricin) the team were able to further our understanding of how lubricin works – and show the drug’s promise as a treatment. The eye-on-a-chip method also offered insight on an unexpected subject: the eye itself. During the study, the researchers found that corneal cells become specialized at their particular jobs faster when the artificial eyelid is blinking on top of them, suggesting that mechanical forces contribute significantly to how cells function. Dan Huh, Associate Professor in the Department of Bioengineering, helped design the eye-on-a-chip platform, and is pleased that it has proved its worth: “We are particularly proud of the fact that our work offers a great and rare example of interdisciplinary efforts encompassing a broad spectrum of research activities, from the design and fabrication of novel bioengineering systems to in vitro modeling of complex human disease to drug testing.”
- J Kang et al., “Association of Statin Use and High Serum Cholesterol Levels with Risk of Primary Open-Angle Glaucoma”, JAMA Ophthalmol, 137, 756 (2019). PMID: 31046067.
- X Jiang et al., “Measuring and compensating ocular longitudinal chromatic aberration,” Optica, 6, 8, 981 (2019).
- Penn Today, “Blinking eye-on-a-chip used for disease modeling and drug testing” (2019). Available at: https://bit.ly/2KDxlOC. Accessed August 8, 2019.