Table 1.
Summary of experiments.
Fig 1.
Gross morphological changes in four-week-old C57BL/6J corneas after exposure to ketamine/xylazine.
Optical coherence tomography (OCT) of the anterior segment (A-C) and slit-lamp images (D-F) of mice injected with ketamine/xylazine show a range of mild (middle column) to severe (right column) corneal damage. In the OCT images, note the presence of corneal opacities between the stromal and epithelial layers. Naïve C57BL/6J mice (no prior injection with ketamine/xylazine; left column) have healthy, clear corneas and are free of opacity.
Fig 2.
Histological changes in four-week-old C57BL/6J corneas after exposure to ketamine/xylazine.
Glutaraldehyde-fixed, plastic-embedded sections stained with toluidine blue at low (A-C) and high (D-F) magnification. Naïve C57BL/6J corneas (left column) showed normal epithelial cell and stromal morphologies. Corneas with mild damage (middle column) and severe damage (right column) showed deposition of a crystalline substance between the epithelial and stromal layers. There was a loss of cellularity of the basal and wing epithelial cells and flattening of the stromal lamellae compared to corneas of naïve mice. Scale bars: A-C, 50 μm; D-F, 10 μm.
Fig 3.
Calcium deposition of damaged corneas.
Paraffin-embedded sections were stained with von Kossa. Calcium deposition is indicated by the brown staining at the interface of the epithelial and stromal layers. Scale bar, 20 μm.
Fig 4.
Rescue of ketamine/xylazine-induced corneal damage by yohimbine.
OCT (A) and slit-lamp (B) images show mice that were injected with yohimbine as a post-anesthesia follow-up are clear from opacity. The corneal epithelial cell layers and the stromal lamellae (C, D) look normal in yohimbine-injected mice. Scale bars: C, 50 μm; D, 10 μm.
Fig 5.
Body temperature loss during ketamine/xylazine anesthesia of 3-week-old (filled circles) versus 3-month-old (open squares) C57BLKS/J mice.
Immediately upon anesthesia, mice were placed on the OCT platform for 2.5 minutes and then given indirect heat for the remainder of the experiment. There is no significant difference (P > 0.05 at all time points, unpaired t-tests) in body temperature loss between young (small) and adult (large) mice (n = 3 mice per group). Error bars are standard deviation.