Purpose:
Animal models play an important role for the development of new medicine for retinal diseases. Accurate non-invasive, safe high volume modalities for in vivo evaluation of the morphologic changes of the retina is essential for understanding the disease mechanisms and for monitoring onset, progression, and response to therapies for effective translation cross-over to human trials.We describe a novel method of non-invasive, fast, high volume, safe and reversible anesthesia for live retinal imaging using a commercially adapted high-resolution spectral domain ocular coherence tomography (Heidelberg Spectralis) system that was simply modified and adapted for invivo confocal laser ophthalmoscopy.
Methods:
Wild type aged(16 months) matched mice (n=5) were rapidly anesthetized using an induction chamber to which gaseous isofluorane was administered in a controlled chamber. Animals was transferred onto a special mount and each retina was individually imaged through a handcrafted rigid contact lens inserted anterior the cornea, while deep general anesthesia was maintained through a specially adapted nose cone with oxygen administration (20%). These animals were re-examination repeatedly with imaging performed including red free, Infra-red, autofluorescence spectrum with spectral domain OCT.
Results:
All animals were imaged safely under reversible anesthesia (mean time of 10 minutes per animal including anesthesia) with high quality images in central and peripheral fields with no morbidity. Significant focal areas of autofluorescence (n=3) and peripheral retinal thinning (n=40 as measured by SD OCT in aged animals was detected.
Conclusions:
We have demonstrated a method using high volume, rapidly reversible general anesthesia utilizing a handcrafted customized contact lens for prolonged imaging. Using a commercialized high resolution Spectral Domain OCT system, we have shown that older animals show retinal OCT measured thinning at the periphery with focal autofluorescence,typical of degenerating retina.
Keywords: retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: non-clinical