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.
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.
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.
Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that play a critical role in transmitting signals from cell-surface molecules to intracellular protein effectors. Key PI3Ks include PI3Kα, PI3Kβ, and PI3Kδ, which are regulated by receptors. The signaling pathway comprising the PI3Ks, along with a Ser/Thr kinase (AKT), a proto-oncogene product (mouse double minute (MDM)2), and a tumor suppressor protein (p53), plays an essential role in experimental proliferative vitreoretinopathy (PVR), which is a fibrotic blinding eye disorder. However, which PI3K isoforms are involved in PVR is unknown. A major characteristic of PVR is the formation of epi (or sub)-retinal membranes that consist of extracellular matrix and cells, including retinal pigment epithelium (RPE) cells, glial cells, and macrophages. RPE cells are considered key players in PVR pathogenesis. Using immunoblotting and immunofluorescence analyses, we herein provide the evidence that PI3Kδ is highly expressed in human RPEs when it is primarily expressed in leukocytes. We also found that PI3Kδ inactivation through two approaches, CRISPR/Cas9-mediated depletion and a PI3Kδ-specific inhibitor (idelalisib), not only blocks vitreous-induced activation of AKT and MDM2 but also abrogates a vitreous-stimulated decrease in p53. Furthermore, we demonstrate that PI3Kδ inactivation prevents vitreous-induced proliferation, migration, and contraction of human RPEs. These results suggest that PI3Kδ may represent a potential therapeutic target for RPE-related eye diseases, including PVR.
Importance: Gun violence represents a substantial public health issue, and firearm-related injuries rank second among the causes of injury-related deaths in children aged 0 to 17 years in the United States. Ocular trauma from firearm-related injuries can lead to devastating vision loss, but little is known to date about the specific demographics and characteristics of such injuries in children. Objective: To evaluate the epidemiologic pattern of pediatric firearm-related ocular injuries. Design, Setting, and Participants: This retrospective analysis used deidentified data from the National Trauma Data Bank, the largest national registry of hospitalized trauma cases in the United States. The firearm-related ocular injuries (n = 1972) of pediatric patients (defined as those younger than 21 years) hospitalized between January 1, 2008, and December 31, 2014, were analyzed. Statistical analyses were conducted from July 15, 2017, to June 15, 2019. Exposure: Firearm-related ocular trauma. Main Outcomes and Measures: Pediatric patients with firearm-related ocular injuries were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes and external causes of injury codes. Patient demographics (age, sex, and race/ethnicity), type of ocular injury, injury intent, geographic location, length of hospital admission, health insurance status, disposition at discharge, Injury Severity Score (ISS), and Glasgow Coma Scale (GCS) score were collected. Results: A total of 8715 firearm-related ocular injuries were identified. Of these injuries, 1972 (22.6%) occurred in pediatric patients, most of whom were male (1678 [85.1%]) and adolescents (1037 [52.6%]), with a mean (SD) age of 15.2 (5) years. Common locations of injury were home (761 [38.6%]) and street (490 [24.8%]). Mean (SD) hospital length of stay was 7.6 (12) days, ISS was 16 (13.1), and GCS score was 11 (5.1). The most common types of firearm-related ocular injuries were open wound of the eyeball (820 [41.6%]) and ocular adnexa (502 [25.5%]), orbital injuries or fractures (591 [30.0%]), and contusion of the eye or adnexa (417 [21.1%]). Patients aged 0 to 3 years had greater odds of unintentional injuries (odds ratio [OR], 4.41; 95% CI, 2.51-7.75; P < .001) and injuries occurring at home (OR, 5.39; 95% CI, 2.81-10.38; P < .001), and those aged 19 to 21 years had greater odds of assault injuries (OR, 2.17; 95% CI, 1.77-2.66; P < .001) and injuries occurring on the street (OR, 1.61; 95% CI, 1.3-1.98; P < .001). Black patients had the greatest odds of having injuries with assault intention (OR, 4.53; 95% CI, 3.68-5.59; P < .001), and white patients had the greatest likelihood for self-inflicted injury (OR, 7.1; 95% CI, 5.92-9.51; P < .001). Traumatic brain injury resulted mostly from self-inflicted trauma (OR, 5.99; 95% CI, 4.16-8.63; P < .001), as did visual pathway injuries (OR, 2.86; 95% CI, 1.95-4.20; P < .001). The inpatient mortality rate was 12.2%. Conclusions and Relevance: This study found that pediatric firearm-related ocular injuries from 2008 through 2014 were predominantly sight-threatening and associated with traumatic brain injury. If the possible risk factors, including sex, age, race/ethnicity, and injury intention, can be confirmed for 2015 through 2019, these findings may be useful in developing strategies to prevent pediatric firearm-related ocular injuries.
The cornea and its adnexa pose a unique situation of a tightly defined set of requirements for its function. This includes: transparency, perfect built to obtain appropriate refractive power, protective barrier from microbial invaders. Moreso, the cornea also endures extreme external physical conditions (temperature, high and low humidity, winds and alike). All these functions are maintained while preserving a constant state of homogenous wetting. Toward that end the cornea is equipped with an elaborated network of sensory neural network. While enabling the blinking reflex and maintaining the physiological steady state of wetting, this neural network also makes the cornea prone to the discomfort that with or without associated changes seen on medical examination. ISOPT Clinical 2018 discussion touched upon this hypercomplex situation, addressing the role of inflammation and its resulting discomfort in dry eye conditions. The discussion also engulfed the emerging neuropathic pain syndrome that is recently gaining more attention. Another related topic was the utilization of autologous serum tears and its ability to provide amelioration to desperate patients. Finally, the panel discussed the issue of treating corneal infection, including when and how to utilize steroids in the course of therapy. We assume the reader will find interest in this discussion that directly addresses issues seen day in and day out in our busy clinics.
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.
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.