Spectral domain optical coherence tomography imaging of spectacular ecdysis in the royal python (Python regius).
OBJECTIVE
To describe using spectral domain optical coherence tomography (SD-OCT), digital slit-lamp biomicroscopy, and external photography, changes in the ophidian cuticle, spectacle, and cornea during ecdysis.


METHODS
Four normal royal pythons (Python regius).


METHODS
Snakes were assessed once daily throughout a complete shed cycle using nasal, axial, and temporal SD-OCT images, digital slit-lamp biomicroscopy, and external photography.


RESULTS
Spectral domain optical coherence tomography (SD-OCT) images reliably showed the spectacular cuticle and stroma, subcuticular space (SCS), cornea, anterior chamber, iris, and Schlemm's canal. When visible, the subspectacular space (SSS) was more distended peripherally than axially. Ocular surface changes throughout ecdysis were relatively conserved among snakes at all three regions imaged. From baseline (7 days following completion of a full cycle), the spectacle gradually thickened before separating into superficial cuticular and deep, hyper-reflective stromal components, thereby creating the SCS. During spectacular separation, the stroma regained original reflectivity, and multiple hyper-reflective foci (likely fragments from the cuticular-stromal interface) were noted within the SCS. The cornea was relatively unchanged in character or thickness throughout all stages of ecdysis. Slit-lamp images did not permit observation of these changes.


CONCLUSIONS
Spectral domain optical coherence tomography (SD-OCT) provided excellent high-resolution images of the snake anterior segment, and especially the cuticle, spectacle, and cornea of manually restrained normal snakes at all stages of ecdysis and warrants investigation in snakes with anterior segment disease. The peripheral spectacle may be the preferred entry point for diagnostic or therapeutic injections into the SSS and for initiating spectacular surgery.
Departments of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
Charlotte A
CA
Tusler
David J
DJ
Maggs
Philip H
PH
Kass
Joanne R
JR
Paul-Murphy
Ivan R
IR
Schwab
Christopher J
CJ
Murphy
D000818:Animals; D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D017821:Boidae / Q000033:anatomy & histology*; D018978:Molting / Q000502:physiology*; D066167:Slit Lamp / Q000662:veterinary*; D041623:Tomography, Optical Coherence / Q000662:veterinary*
cornea; cuticle; ophidia; snake; spectacle; subspectacular space