Ex vivo analysis of ultraviolet radiation transmission through ocular media and retina in select species.
Level 5 - mechanism / opinion, no new human data
Ex vivo laboratory tissue study on animal and human enucleated eyes.
PubMed 37356536 · doi:10.1016/j.exer.2023.109550
What was done
Spectrophotometry was used to measure ultraviolet (UV; 200–400 nm) and visible (up to 800 nm) radiation transmission through intact ocular media (cornea, aqueous humor, lens, vitreous humor) and retina in 54 enucleated globes from cats (n = 6), dogs (n = 18), pigs (n = 10), rabbits (n = 6), horses (n = 10), and humans (n = 4). A 5–10 mm circular window of sclera and choroid was surgically removed from the posterior pole while preserving the retina in all species except horses. Glass coverslips were placed on rabbit and horse preparations to address tissue fragility.
What was found
The abstract reports relative cross-species comparisons without specific numerical percentages: cat and dog globes permitted the highest proportion of UV radiation transmission, whereas pig and human globes permitted the least. Rabbit and horse eyes demonstrated low levels of UV transmission.
Why it matters
Demonstrating interspecies variations in ocular UV transmission clarifies differences in retinal UV exposure, informing comparative visual ecology and safety standards for working, service, and companion animals.
Limits
The abstract reports purely qualitative/relative comparisons without exact transmission percentages or variance metrics. Sample sizes were small, particularly for humans (n = 4), cats (n = 6), and rabbits (n = 6). Methodological inconsistencies were present across species, including the removal of the retina in horses and the addition of glass coverslips in horses and rabbits. Post-mortem tissue changes ex vivo may differ from in vivo optical properties.
Cited by
- supports The human cornea and lens block short wavelengths of light such as UV radiation from penetrating deep into the eye.