ARVO in Focus: Carbon Cornea and More
The latest research from Translational Vision Science & Technology
Geoffrey Potjewyd | | 3 min read | News
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Carbon-infused materials may no longer be immediately associated with the frames of high-performance sports cars and bike frames – at least in ophthalmology. Researchers have incorporated carbon nanostructures – made from single-walled carbon nanotubes and graphene – into the corneal stroma to improve the physical properties of the tissue (1). This feat of nanoengineering looks directly applicable to keratoconus but could pave the way for future applications in ocular tissue reinforcement.
ROCK the boat
Dogs with primary corneal endothelial degeneration (PCED) can not only get their condition treated but also take us one step closer to trials in human participants. The topical drug, called ripasudil, was well tolerated and had a therapeutic benefit in 62 percent of the dogs (2). Unfortunately, the condition progressed in the other 38 percent, but the authors note that the rate of progression was still slower than for historical controls. Ripasudil is a Rho-associated kinase (ROCK) inhibitor currently used in Japan for the treatment of ocular hypertension and glaucoma. ROCK inhibitors have been used in lab tissue models to promote corneal endothelial cell proliferation and adhesion, and are also promising treatment for Fuchs’ endothelial corneal dystrophy.
There is a historical precedent for controversy when characterizing the bands of the retina – and specifically, the origin of band 2. Researchers have found supporting evidence that i) band 2 of the retina partially overlaps with the ellipsoid (because of the photoreceptor inner segment length) and ii) the inner ellipsoid must also be within band 2, as suggested by prior quantitative measurements (3). The association of band 2b with rods and 2a with cones, which the researchers suggested, would explain certain findings showing that rods and cones form part of band 2. The images were taken using the latest technical advancements in visible light OCT, and the results provide extra relevance to the interpretation of clinical NIR OCT. In the future, these anatomical analyses may contribute to the understanding of certain retinal diseases.
Retinal prostheses are becoming increasingly technologically advanced. One important factor for the success and safety of these prostheses is the electrode to retina (ER) distance. But how consistent are the measurements of ER between different sites and even different people? Fortunately, it has been established that there is a high level of accuracy in ER measurements across locations and professionals (4). Pragmatically, this news means that patients with retinal prostheses will not have to fear their ophthalmologist going on holiday – or moving across (or out of) the country!
The anatomical variations in effective lens position require compensation in the IOL power formula to counteract systematic bias. Such changes in formula could result in a different IOL power. The consequences of lens variation mainly concern eyes that are receiving high power IOLs, and the effect on corneal power is minimal (5).
- J Silvestre et al., Transl Vis Sci Technol, 11, 1 (2022). PMID: 36048013.
- SR Michalak et al., Transl Vis Sci Technol, 11, 2 (2022). PMID: 36048012.
- VJ Srinivasan et al., Transl Vis Sci Technol, 11, 3 (2022). PMID: 36053140.
- CJ Abbott et al., Transl Vis Sci Technol, 11, 4 (2022). PMID: 36066322.
- D Gatinel et al., Transl Vis Sci Technol, 11, 5 (2022). PMID: 36069859.