Keep an eye on ophthalmology
Some major recent discoveries
For this month of May, time to focus on a new area to set our sights. Let’s look at all the stuff coming out on eyes.
We’ll start with the brain's waste disposal system, the glymphatics; it clears out toxic amyloid beta proteins that have been associated with the development of Alzheimer's disease.
Recently, researchers report using retinal scans to see these deposits in early stages of the pathology. To see how it disposes this waste, lab mice were injected in their eyes with fluorescently labelled amyloid beta proteins, which were then traced, showing shuttling through the optic nerve. Hours later, fluorescent proteins were found carried all the way into neck lymph nodes.
Now on to gene therapy, or more likely anti-gene therapy: the antisense oligonucleotide called sepofarsen. This short RNA molecule works by increasing normal CEP290 protein levels in the photo receptors after uptake from an intraorbital injection. It was tested in patients diagnosed with Leber congenital amaurosis —an eye disorder that primarily affects the retina—who have a CEP290 mutation.
After a single injection of sepofarsen, more than a dozen measurements of visual function and retinal structure showed large improvements supporting a biological effect from the treatment. A key finding from the case was that this biological effect was relatively slow in uptake. The researchers saw vision improvement after one month, but the patient's vision reached a peak effect after month two. Most striking, the improvements remained when tested over 15 months after the first and only injection. -Nature Medicine (2021).
And for strabismus and amblyopia, there’s a real cool new finding. Med school dogma teaches that ‘lazy eye’ loses the ability to see depth. But it was never actually tested objectively. Finally, scientists tested subjects with strabismus with pictoral images, for their relative depth perception abilities using linear cues of perspective. They were just as able as unimpaired subjects with normal binocular vision. So, actually, they still can see the world in full 3D, despite the focal misalignment.
May your world, too, be further expanded in all dimensions, with these short reports of hot picks in biotech.
REFERENCES
Retina scans could help identify Alzheimer’s https://www.news-medical.net/news/20170822/Retina-scans-could-help-identify-Alzheimers.aspx
An ocular glymphatic clearance system removes β-amyloid from the rodent eye https://stm.sciencemag.org/content/12/536/eaaw3210
Durable vision improvement after a single treatment with antisense oligonucleotide sepofarsen: a case report, Nature Medicine (2021). https://www.nature.com/articles/s41591-021-01297-7
Common eyesight myth about strabismus demystified (2021, January) https://medicalxpress.com/news/2021-01-common-eyesight-myth-strabismus-demystified.html
Giedre Zlatkute et al. Unimpaired perception of relative depth from perspective cues in strabismus, Royal Society Open Science (2020). https://royalsocietypublishing.org/doi/10.1098/rsos.200955
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Ming-fai Fong et al, Correction of amblyopia in cats and mice after the critical period, eLife (2021). DOI: 10.7554/eLife.70023 https://elifesciences.org/articles/70023