The adult zebrafish retina: In vivo optical sectioning with Confocal Scanning Laser Ophthalmoscopy and Spectral-Domain Optical Coherence Tomography

Abstract

Non-invasive imaging is an invaluable diagnostic tool in ophthalmology. Two imaging devices, the scanning laser ophthalmoscope (SLO) and spectral domain optical coherence tomography (SDOCT), emerged from the clinical realm to provide research scientists with a real-time view of ocular morphology in living animals. We utilized these two independent imaging modalities in a complementary manner to perform in vivo optical sectioning of the adult zebrafish retina. Due to the very high optical power of the zebrafish lens, the confocal depth of field is narrow, allowing for detailed en face views of specific retinal layers, including the cone mosaic. Moreover, we demonstrate that both native reflectance, as well as fluorescent features observed by SLO, can be combined with axial in-depth information obtained by SDOCT. These imaging approaches can be used to screen for ocular phenotypes and monitor retinal pathology in a non-invasive manner.

Neurodegeneration, Neuroprotection and Regeneration in the Zebrafish Retina

“…SD-OCT devices used to image rodent retinas have been further adapted to study the zebrafish retina in high resolution. Due to the small size and optical properties of the zebrafish eye, en face images of the photoreceptor matrix can be produced at a single-cell resolution that is not possible with rodent and human eyes [ 125 , 126 ]. Quantification and tracking of individual cones is highly reproducible using this approach [ 127 ].…”

Implantable anti-angiogenic scaffolds for treatment of neovascular ocular pathologies

“…The model is useful for the evaluation of a variety of ocular therapeutics [117][118][119][120][121][122][123][124][125]. Notably, the laserinduced retinal disease model shares the following similarities to the pathologic burden in humans: (a) rapid neovascularization of the retina and (b) development of inflammation and retinal edema.…”

“…Notably, the laserinduced retinal disease model shares the following similarities to the pathologic burden in humans: (a) rapid neovascularization of the retina and (b) development of inflammation and retinal edema. Following laser treatment, the rats can receive an intravitreal injection of a therapeutic into the vitreous humor via the pars plana immediately following confirmation of retinal neovascularization and retinal edema by confocal scanning laser ophthalmoscopy (cSLO) and SD-OCT. [121,126] Prior to starting anti-angiogenic treatment with the injectable formulations, it is important to monitor the onset and progression of clinical symptoms of disease progression. Fundoscopy, fluorescein angiography, and SD-OCT may be used to image neovascularization induced in the posterior segment [121,122,[126][127][128][129][130][131][132][133][134][135][136][137][138].…”

Interspecies Variation of Outer Retina and Choriocapillaris Imaged With Optical Coherence Tomography

“…Less frequently used species include nonhuman primates, [25][26][27] rabbits, [28][29][30][31] pigs, 32,33 minipigs, 34 guinea pigs, 35 dogs, cats, [36][37][38] tree shrews, 39 gerbils, 40 and ground squirrels. 41 Frogs [42][43][44] and zebrafish 45,46 are the more commonly used nonmammalian species. Despite the common use of various animal species in preclinical ophthalmic research involving OCT, no consensus exists regarding the nomenclature of the outer retinal bands (ORBs) distinguishable on OCT in different species.…”