Publications

2019

Children born preterm with periventricular leukomalacia (PVL) demonstrate increased difficulties with tasks requiring visuomotor integration. The visuomotor integration network encompasses brain regions within frontal, parietal, and occipital cortices. Because of their proximity to the lateral ventricle the underlying white matter pathways are at a high risk of damage following PVL-related hypoxic-ischemic white matter injury. This study provides an exploratory analysis of the structural and functional connections within the visuomotor integration network, along with an a priori evaluation of the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and frontal aslant tract. For each pathway, tracts within both hemispheres revealed decreased volume and number of reconstructed fibers and an increase in quantitative anisotropy and generalized fractional anisotropy. The connectivity results also indicate that there may be changes to both the structural integrity and functional integration of neural networks involved with visuomotor integration functions in children with PVL.
Bennett C, Bex P, Bauer C, Merabet L. The Assessment of Visual Function and Functional Vision. Semin Pediatr Neurol. 2019;31:30–40.
The complete assessment of vision-related abilities should consider visual function (the performance of components of the visual system) and functional vision (visual task-related ability). Assessment methods are highly dependent upon individual characteristics (eg, the presence and type of visual impairment). Typical visual function tests assess factors such as visual acuity, contrast sensitivity, color, depth, and motion perception. These properties each represent an aspect of visual function and may impact an individual's level of functional vision. The goal of any functional vision assessment should be to measure the visual task-related ability under real-world scenarios. Recent technological advancements such as virtual reality can provide new opportunities to improve traditional vision assessments by providing novel objective and ecologically valid measurements of performance, and allowing for the investigation of their neural basis. In this review, visual function and functional vision evaluation approaches are discussed in the context of traditional and novel acquisition methods.
Kran B, Lawrence L, Mayer L, Heidary G. Cerebral/Cortical Visual Impairment: A Need to Reassess Current Definitions of Visual Impairment and Blindness. Semin Pediatr Neurol. 2019;31:25–29.
Cerebral/cortical visual impairment (CVI) is characterized by higher order visual dysfunction caused by injury to the retrogeniculate visual pathways and brain structures which subserve visual processing. CVI has become the leading cause of significant vision loss in children in developed countries, but continues to be an under-recognized cause of visual disability with respect to services aimed at maximizing visual development. Current criteria which are used to define visual disability rely on measures of visual acuity and visual field. Many children who require specialized vision services do not qualify, because these standard definitions of vision impairment do not account for CVI. In order to appropriately identify patients with CVI and offer the resources which may positively impact functional use of vision, the definition of visual impairment and blindness needs to be modified. This commentary calls for a change in the definition of visual impairment and blindness to acknowledge those persons with brain-based vision impairment.
Saeedi O, Elze T, D’Acunto L, Swamy R, Hegde V, Gupta S, Venjara A, Tsai J, Myers J, Wellik S, De Moraes CG, Pasquale L, Shen L, Boland M. Reply. Ophthalmology. 2019;126(10):e78-e79.
Mazel E, Bailin E, Tietjen M, Palmer P. A Questionnaire Assessing What Teachers of the Visually Impaired Know About Cortical/Cerebral Vision Impairment. Semin Pediatr Neurol. 2019;31:41–47.
Cortical/cerebral visual impairment (CVI) is now the main cause of visual impairment in developed countries, yet it remains poorly understood. Four hundred and ninteen teachers of the visually impaired (TVIs) from across the United States responded to a questionnaire targeted at evaluating the preparedness of TVIs to serve their students with CVI. The TVIs were asked about their background knowledge, their abilities to assess a student with CVI, and their abilities to apply what they know to best help their students. The primary finding was that there is a perceived unmet need for TVIs to receive formal training in CVI during their certification. The results of this survey provide a foundation for future research on CVI knowledge and education among TVIs.
Kruszka P, Hu T, Hong S, Signer R, Cogné B, Isidor B, Mazzola S, Giltay J, Gassen K, England E, Pais L, Ockeloen C, Sanchez-Lara P, Kinning E, Adams D, Treat K, Torres-Martinez W, Bedeschi M, Iascone M, Blaney S, Bell O, Tan T, Delrue MA, Jurgens J, Barry B, Engle E, Savage S, Fleischer N, Martinez-Agosto J, Boycott K, Zackai E, Muenke M. Phenotype delineation of ZNF462 related syndrome. Am J Med Genet A. 2019;179(10):2075–2082.
Zinc finger protein 462 (ZNF462) is a relatively newly discovered vertebrate specific protein with known critical roles in embryonic development in animal models. Two case reports and a case series study have described the phenotype of 10 individuals with ZNF462 loss of function variants. Herein, we present 14 new individuals with loss of function variants to the previous studies to delineate the syndrome of loss of function in ZNF462. Collectively, these 24 individuals present with recurring phenotypes that define a multiple congenital anomaly syndrome. Most have some form of developmental delay (79%) and a minority has autism spectrum disorder (33%). Characteristic facial features include ptosis (83%), down slanting palpebral fissures (58%), exaggerated Cupid's bow/wide philtrum (54%), and arched eyebrows (50%). Metopic ridging or craniosynostosis was found in a third of study participants and feeding problems in half. Other phenotype characteristics include dysgenesis of the corpus callosum in 25% of individuals, hypotonia in half, and structural heart defects in 21%. Using facial analysis technology, a computer algorithm applying deep learning was able to accurately differentiate individuals with ZNF462 loss of function variants from individuals with Noonan syndrome and healthy controls. In summary, we describe a multiple congenital anomaly syndrome associated with haploinsufficiency of ZNF462 that has distinct clinical characteristics and facial features.
Ross A, Bengani L, Tulsan R, Maidana D, Salvador-Culla B, Kobashi H, Kolovou P, Zhai H, Taghizadeh K, Kuang L, Mehta M, Vavvas D, Kohane D, Ciolino J. Topical sustained drug delivery to the retina with a drug-eluting contact lens. Biomaterials. 2019;217:119285.
Intravitreal injections and implants are used to deliver drugs to the retina because therapeutic levels of these medications cannot be provided by topical administration (i.e. eye drops). In order to reach the retina, a topically applied drug encounters tear dilution, reflex blinking, and rapid fluid drainage that collectively reduce the drug's residence time on the ocular surface. Residing under the tears, the cornea is the primary gateway into the eye for many topical ophthalmic drugs. We hypothesized that a drug-eluting contact lens that rests on the cornea would therefore be well-suited for delivering drugs to the eye including the retina. We developed a contact lens based dexamethasone delivery system (Dex-DS) that achieved sustained drug delivery to the retina at therapeutic levels. Dex-DS consists of a dexamethasone-polymer film encapsulated inside a contact lens. Rabbits wearing Dex-DS achieved retinal drug concentrations that were 200 times greater than those from intensive (hourly) dexamethasone drops. Conversely, Dex-DS demonstrated lower systemic (blood serum) dexamethasone concentrations. In an efficacy study in rabbits, Dex-DS successfully inhibited retinal vascular leakage induced by intravitreal injection of vascular endothelial growth factor (VEGF). Dex-DS was found to be safe in a four-week repeated dose biocompatibility study in healthy rabbits.
VanderVeen D, Cataltepe S. Anti-vascular endothelial growth factor intravitreal therapy for retinopathy of prematurity. Semin Perinatol. 2019;43(6):375–380.
Retinopathy of prematurity treatment modalities have expanded over the years, from cryotherapy to laser therapy and now, anti-vascular endothelial factor (VEGF) therapy by intravitreal injection. Use of anti-VEGF treatment varies regionally and depends on multiple factors including severity and progression of ROP, availability of alternative treatments, experience of the local ophthalmologists, medical status of the infant, and expectations for long-term follow-up. While the advantages and disadvantages of anti-VEGF intravitreal treatment on the eye are relatively well-described, few studies provide information about potential long-term systemic effects of this treatment, which is known to transiently reduce systemic VEGF concentrations.