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. 2015 Dec;5(1):33.
doi: 10.1186/s12348-015-0064-x. Epub 2015 Nov 19.

Three-dimensional spectral domain optical coherence tomography and light microscopy of an intravitreal parasite

Aziz A Khanifar  1 , Michael J Espiritu  2 , Jane S Myung  3 , Grant D Aaker  4 , Audrey N Schuetz  5 , Donald J D'Amico  6 , R V Paul Chan  7   8
Affiliations

Three-dimensional spectral domain optical coherence tomography and light microscopy of an intravitreal parasite

Aziz A Khanifar et al. J Ophthalmic Inflamm Infect. 2015 Dec.

Abstract

Background: Various imaging modalities play a role in diagnosing parasitic infections of the eye. We describe the spectral domain optical coherence tomography (SD-OCT) findings of an intravitreal parasite with subsequent evaluation by light microscopy.

Findings: This is a case report of a 37-year-old Ecuadorian man who presented with uveitic glaucoma and a new floater in his left eye for 1 week's duration. Full ophthalmic examination revealed an intravitreal parasite. Color fundus photography, fluorescein angiography (FA), ocular ultrasonography (US), and SD-OCT were performed. The parasite was removed via 23-gauge pars plana vitrectomy and sent to pathology for evaluation. Color fundus photography and ocular ultrasonography demonstrated an elongated foreign body within the vitreous above the retina. FA demonstrated minimal vascular changes in the vicinity of the parasite. SD-OCT was utilized to visualize the parasite and to create a three-dimensional (3D) image. The parasite was determined to be most consistent with Gnathostoma spp. by morphologic analysis.

Conclusions: This is the first reported case of SD-OCT of an intravitreal parasite with corresponding evaluation by pathology. SD-OCT allows non-invasive, high-resolution visualization and 3D reconstruction of parasitic anatomy which may help establish tomographic criteria for species identification.

Keywords: Gnathostoma; Gnathostomiasis; Ophthalmomyiasis; Optical coherence tomography; Parasitic infection; Retinal imaging.

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Figures

Fig. 1
Fig. 1
a Wide-angle color fundus photograph of the patient’s left eye demonstrating the parasite (white oval) within the vitreous and nasal to the optic disc. b Higher magnification color photograph of the intravitreal parasite
Fig. 2
Fig. 2
Wide-angle fluorescein angiogram demonstrating vascular sheathing (white arrow) in the region where the parasite was initially visualized
Fig. 3
Fig. 3
Ocular ultrasonography demonstrating the parasite (white arrow) within the vitreous. Note that the parasite is not in contact with the retina
Fig. 4
Fig. 4
Spectral domain optical coherence tomography (SD-OCT) images of the parasite demonstrating two concentric circles within the vitreous above the retina. Note that the inner circle is hyper-reflective superiorly (top image) and hypo-reflective inferiorly (bottom image)
Fig. 5
Fig. 5
a Three-dimensional reconstruction of spectral domain optical coherence tomography (SD-OCT) images of the intravitreal parasite. b Additional view of SD-OCT image from different angles
Fig. 6
Fig. 6
Light microscopy photograph of the parasite removed from the patient’s vitreous cavity. The cuticle has been partially removed
Fig. 7
Fig. 7
Higher magnification photograph of the rostral portion of the parasite demonstrating minute cuticular spines encircling the cuticular armature of the head bulb
See this image and copyright information in PMC

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