Retinal structural and microvascular abnormalities in retinal dysplasia imaged by OCT and OCT angiography.

OBJECTIVE: To describe the in vivo structural characteristics of multifocal and geographic retinal dysplasia visualized with advanced retinal imaging including confocal scanning laser ophthalmoscopy (cSLO), optical coherence tomography (OCT), en face OCT, and the novel vascular imaging technique OCT angiography (OCTA). DOGS STUDIED AND PROCEDURES: Two dogs were diagnosed with unilateral multifocal or geographic retinal dysplasia and underwent advanced retinal imaging under general anesthesia at the Retinal Disease Studies Facility of the University of Pennsylvania. RESULTS: In both cases, the morphological pattern of the lesions was similar including outer retinal folds that invaginated and formed tubular retinal rosettes, surrounding a central inner retinal thickening (multifocal) or plaque (geographic). The two dogs had multiple vascular anomalies in the lesions such as increased tortuosity, abnormal change of vessel diameter including aneurysms and capillary network disruption. We also identified increased autofluorescence by AF cSLO with short wavelength light source (488 nm and barrier filter at 500 nm), and several areas of photoreceptor loss associated with the lesions. CONCLUSION: The use of OCTA allowed the identification of microvascular abnormalities associated with multifocal and geographic retinal dysplasia in two dogs. To our knowledge, this is the first report where the dye-free OCTA technique is used to study vascular lesions in canine retinas.

Optic nerve colobomas associated with unilateral focal serous retinal detachment in a dog - In-vivo imaging and outcome following laser retinopexy.

PURPOSE: To describe the ophthalmoscopic, in-vivo imaging, fluorescein angiography, and therapeutic photocoagulation outcome in a case of bilateral optic nerve colobomas associated with focal unilateral retinal detachment in a dog. METHODS: Pretraining eye examination of a 1.6-year-old female German shepherd service dog showed a focal juxta-papillary bullous retinal separation in the right eye. In vivo imaging and angiography were performed under general anesthesia using optical coherence tomography. Nonoverlapping diode laser burns were applied through an operating microscope adapter to selected areas along the leading margins of the detachment. RESULTS: The funduscopic examination and in-vivo imaging revealed bilateral optic nerve colobomas associated with a focal bullous detachment in the right eye. Fluorescein angiography showed absence of blood vessel leakage and absence of staining inside of the retinal elevation. Photocoagulation induced immediate changes in retinal layer reflectivity. Three months post-photocoagulation, the retinal detachment had improved and scarring of the burns was visible. One and two years post-procedure, the retinal detachment resolved. CONCLUSIONS: Optical coherence tomography (OCT) imaging provides a detailed analysis of the retinal abnormalities associated with the clinical lesion. Laser retinopexy is a valid therapeutic option to limit the extension of the detachment.

Focal/multifocal and geographic retinal dysplasia in the dog-In vivo retinal microanatomy analyses.

PURPOSE: To examine the in vivo microanatomy of retinal folds and geographic lesions in dogs with acquired or inherited retinal dysplasia. MATERIAL AND METHODS: Thirteen dogs had retinal microanatomy evaluation under general anesthesia using cSLO/sdOCT; two eyes had noninherited multifocal retinal folds, five had inherited multifocal retinal folds (drd1 or drd2), and 10 geographic retinal dysplasia. Retinas from two drd2 carrier dogs were examined by histology and immunohistochemistry (IHC) after in vivo imaging. RESULTS: Retinal folds are the common feature of acquired focal/multifocal or geographic retinal dysplasia, are indistinguishable structurally from those associated with syndromic oculoskeletal dysplasia, and represent outer nuclear layer invaginations and rosettes visible by sdOCT. In dogs heterozygous for oculoskeletal dysplasia, the folds form clusters in a perivascular distribution along superior central vessels. IHC confirmed photoreceptor identity in the retinal folds. The geographic dysplasia plaques are not focally detached, but have inner retinal disorganization and intense autofluorescence in cSLO autofluorescence mode that is mainly limited to the geographic lesion, but is not uniform and in some extends beyond the plaques. CONCLUSION: We propose that the autofluorescent characteristic of the geographic lesions is associated with an inner retinal disruption associated with perivascular or infiltrating macrophages and phagocytosis of cellular debris. As well, we suggest restructuring the examination forms to distinguish the folds that are sporadically distributed from those that have a perivascular distribution as the latter likely represent carriers for drd. In this latter group, DNA testing would be a helpful tool to provide specific breeding advice.

Being in-between: A model of cultural identity negotiation for emerging adult immigrants.

This qualitative study explored the cultural identity negotiation of young adult immigrants. Using a grounded theory research design, 10 semistructured interviews were conducted with emerging adult immigrants (EAI), ages 19-27. Results yielded a substantive model of cultural identity negotiation (MCIN) for EAI and posited that One's Motivation and Sense of Agency to Negotiate Cultural Identity is at the core of how participants navigate their cultural identities. This model included 6 major categories: (a) Family Cultural Rigidity; (b) Connections Specific to Canada; (c) Connection to a Same Cultured Community; (d) Sense of Permanency; (e) Desire to Preserve Culture of Origin; (f) Desire to Fit in to Canadian Culture, as well as 2 overarching factors (Dimension of Time and Dimension of Age), which were found to be influential on participants' cultural identity negotiation. The model also included the identification of 4 approaches to cultural identity negotiation: (a) Blended; (b) Dual; (c) Disconnected; and (d) Intermediate. The MCIN for EAI is discussed in terms of the current literature on cultural identity formation as well as implications for counseling psychology training and practice. Recommendations for further research are also suggested. (PsycINFO Database Record