Frizzled 4 regulates ventral blood vessel remodeling in the zebrafish retina.

BACKGROUND: Familial exudative vitreoretinopathy (FEVR) is a rare congenital disorder characterized by a lack of blood vessel growth to the periphery of the retina with secondary fibrovascular proliferation at the vascular-avascular junction. These structurally abnormal vessels cause leakage and hemorrhage, while the fibroproliferative scarring results in retinal dragging, detachment and blindness. Mutations in the FZD4 gene represent one of the most common causes of FEVR. METHODS: A loss of function mutation resulting from a 10-nucleotide insertion into exon 1 of the zebrafish fzd4 gene was generated using transcription activator-like effector nucleases (TALENs). Structural and functional integrity of the retinal vasculature was examined by fluorescent microscopy and optokinetic responses. RESULTS: Zebrafish retinal vasculature is asymmetrically distributed along the dorsoventral axis, with active vascular remodeling on the ventral surface of the retina throughout development. fzd4 mutants exhibit disorganized ventral retinal vasculature with discernable tubular fusion by week 8 of development. Furthermore, fzd4 mutants have impaired optokinetic responses requiring increased illumination. CONCLUSION: We have generated a visually impaired zebrafish FEVR model exhibiting abnormal retinal vasculature. These fish provide a tractable system for studying vascular biology in retinovascular disorders, and demonstrate the feasibility of using zebrafish for evaluating future FEVR genes identified in humans.

Charting the Globe: How Technologies Have Affected Our Understanding of Retinal Findings in Abusive Head Trauma/Shaken Baby Syndrome.

Purpose: Ocular findings such as retinal hemorrhages are common in abusive head trauma (AHT). Binocular indirect ophthalmoscopy has been the standard for assessing the eyes of children who are victims of AHT. However, technological advances have changed our understanding of retinal findings in AHT.Methods: Literature review on AHT - retinal findings, imaging technologies, models of representation, and telemedicine applications.Results: Many studies suggest vitreoretinal traction from repetitive acceleration-deceleration shearing forces during shaking plays an important role in the development of retinal findings in AHT. This is further supported by different imaging modalities [optical coherence tomography (OCT); magnetic resonance imaging (MRI); fluorescein angiography (FA)] and models of representation (animal and mechanical models; finite element analysis).Conclusion: Emerging technologies have augmented our diagnostic abilities, enhanced our understanding regarding the pathophysiology of retinal findings, and strengthened the link between vitreoretinal traction and ocular pathology in AHT. Telemedicine is also starting to play an important role in AHT.

Peripheral Ulcerative Keratitis Secondary to Atypical Hemolytic Uremic Syndrome.

PURPOSE: To report a case of peripheral ulcerative keratitis secondary to atypical hemolytic uremic syndrome. METHODS: We report the case of a 76-year-old man who presented with bilateral aggressive peripheral ulcerative keratitis. Clinical examinations and investigations are reported from the patients' admission. RESULTS: The patient had an extended workup for autoimmune and infectious etiologies that all returned negative. The laboratory work in conjunction with renal biopsy and clinical symptoms were consistent with atypical hemolytic uremic syndrome. The patient was treated with systemic steroids for his peripheral ulcerative keratitis and underlying systemic disease. Corneal glueing and amniotic membrane grafting was also performed. CONCLUSIONS: To our knowledge, we report the first known case of peripheral ulcerative keratitis secondary to atypical hemolytic uremic syndrome. In cases where the standard workup is negative, this diagnosis should be considered because it can have significant systemic morbidity.

Ergonomics in the operating room: it doesn't hurt to think about it, but it may hurt not to!

Ergonomics has gained increasing recognition as an integral component of career longevity in ophthalmology. Residents and fellows may encounter unique ergonomic challenges when learning surgical techniques. A systematic review of the literature, specifically looking for recommendations on optimizing ergonomics in the operating room (OR) and articles that explicitly mentioned suggestions for trainees, was conducted. Of the identified 41 pieces of literature, 31 specifically mentioned ergonomics in the OR, 10 discussed vitreoretinal surgery, 2 mentioned strabismus surgery, and 2 described ergonomics in oculoplastics surgeries. Only 9 of the 41 articles explicitly mentioned either residents or fellows. Based on this review, as well as anecdotal experience, recommendations for residents, fellows, and staff ophthalmologists while working in the OR were compiled. To help offset risk for musculoskeletal injury, recommendations related to relaxation, movement, and maintenance of ergonomic focus are proposed. In addition, methods to optimize ergonomics for the patient, surgeon, surgical bed, foot pedals, surgeon's chair, and the microscope are identified. Trainees may be at particular risk for injury owing to their placement at the surgical bed, and the fact that they may be less likely to get set up ergonomically either owing to a lack of awareness and teaching on the subject, or secondary to perceived time pressures in the OR. Ergonomics should ideally be considered across all domains of life, including in the OR, clinic, and office and at home. The earlier proper positioning is adopted and becomes habitual, the less likely potentially career-threatening musculoskeletal disorders will develop.