The epidemiology of strabismus and cataracts within a pediatric population in Saint Vincent and the Grenadines: an analysis of 201 consecutive cases.

PURPOSE: Childhood cataracts and strabismus are among the most common causes of visual impairment in children worldwide, and prompt diagnosis and correction can significantly reduce disease burden. In certain regions, including the Eastern Caribbean, access to adequate treatment can be limited and epidemiological data scarce. This study aims to analyze the epidemiological data of pediatric strabismus and cataract cases in St. Vincent and the Grenadines. METHODS: The setting of the study is a clinical practice including 201 patients between the age of 0 to 19 who received care with World Pediatric Project (WPP). Factors analyzed include patient age, sex, and type of cataract or strabismus. The findings were compared to publicly available demographic information. RESULTS: The cases were divided into cataract (n=51), strabismus (n=134), and both strabismus and cataract (n=16). Mean ages (years) were 5.96, 5.54, and 4.50, respectively. The most frequent type of cataract and strabismus were congenital (n=25) and esotropia (n=95), respectively. The highest annual cumulative incidence was 31 and 49 cases per 100,000 people for cataracts and strabismus, respectively. CONCLUSION: This study provides regional epidemiological data on pediatric strabismus and cataracts. Further studies can expand the patient population by increasing collaboration with local providers. Ultimately, these findings can offer a basis for which additional epidemiological studies can be performed and help guide public health efforts to prevent visual impairment in St. Vincent and the Grenadines.

Bifocal pineal and suprasellar germinomas with posterior fossa metastases in an adolescent patient.

Central nervous system germ cell tumors are rare lesions that are more frequently seen in the pediatric age group. Intracranial germinomas are a type of these germ cell tumors and commonly arise in the pineal region, suprasellar region, or less frequently at both areas (bifocal). Common features of this tumor depend on the location of the lesion(s) and include Parinaud's syndrome, obstructive hydrocephalus, diabetes insipidus, panhypopituitarism, strabismus, and visual acuity defects. We report a case of bifocal pineal and suprasellar germinoma with posterior fossa metastases in a 15-year-old male patient. The involvement of the third ventricular floor and nonthickened inferior pituitary stalk of the suprasellar lesion suggest that it is a metastasis of a primary pineal lesion rather than a dual-primary. This distinction, with the presence of posterior fossa metastases, favors the use of more aggressive treatment with combination radiation therapy and chemotherapy for a better outcome.

Ophthalmic abnormalities in Wieacker-Wolff syndrome.

Wieacker-Wolff syndrome is an X-linked condition caused by variants of the ZC4H2 gene that results in in utero muscular weakness that manifests clinically as arthrogryposis congenita as well as facial and bulbar weakness. We report the case of a young girl with a de novo pathogenic deletion in the ZC4H2 gene and clinical features consistent with Wieacker-Wolff syndrome. Common eye manifestations of the syndrome reported in the literature include ptosis, strabismus, and oculomotor apraxia. The overall incidence of these manifestations is 56%.

Oculodentodigital Dysplasia: A Case Report and Major Review of the Eye and Ocular Adnexa Features of 295 Reported Cases.

Oculodentodigital dysplasia (ODDD) is a rare genetic disorder associated with a characteristic craniofacial profile with variable dental, limb, eye, and ocular adnexa abnormalities. We performed an extensive literature review to highlight key eye features in patients with ODDD and report a new case of a female patient with a heterozygous missense GJA1 mutation (c.65G>A, p.G22E) and clinical features consistent with the condition. Our patient presented with multiple congenital anomalies including syndactyly, microphthalmia, microcornea, retrognathia, and a small nose with hypoplastic alae and prominent columella; in addition, an omphalocele defect was present, which has not been reported in previous cases. A systematic review of the published cases to date revealed 91 literature reports of 295 individuals with ODDD. There were 73 different GJA1 mutations associated with these cases, of which the most common were the following missense mutations: c.605G>A (p.R202H) (11%), c.389T>C (p.I130T) (10%), and c.119C>T (p.A40V) (10%). Mutations most commonly affect the extracellular-1 and cytoplasmic-1 domains of connexin-43 (gene product of GJA1), predominately manifesting in microphthalmia and microcornea. The syndrome appears with an approximately equal sex ratio. The most common eye features reported among all mutations were microcornea, microphthalmia, short palpebral fissures, and glaucoma.

Shank3-deficient thalamocortical neurons show HCN channelopathy and alterations in intrinsic electrical properties.

KEY POINTS: Shank3 increases the HCN channel surface expression in heterologous expression systems. Shank3Δ13-16 deficiency causes significant reduction in HCN2 expression and Ih current amplitude in thalamocortical (TC) neurons. Shank3Δ13-16 - but not Shank3Δ4-9 -deficient TC neurons share changes in basic electrical properties which are comparable to those of HCN2-/- TC neurons. HCN channelopathy may critically mediate events downstream from Shank3 deficiency. ABSTRACT: SHANK3 is a scaffolding protein that is highly enriched in excitatory synapses. Mutations in the SHANK3 gene have been linked to neuropsychiatric disorders especially the autism spectrum disorders. SHANK3 deficiency is known to cause impairments in synaptic transmission, but its effects on basic neuronal electrical properties that are more localized to the soma and proximal dendrites remain unclear. Here we confirmed that in heterologous expression systems two different mouse Shank3 isoforms, Shank3A and Shank3C, significantly increase the surface expression of the mouse hyperpolarization-activated, cyclic-nucleotide-gated (HCN) channel. In Shank3Δ13-16 knockout mice, which lack exons 13-16 in the Shank3 gene (both Shank3A and Shank3C are removed) and display a severe behavioural phenotype, the expression of HCN2 is reduced to an undetectable level. The thalamocortical (TC) neurons from the ventrobasal (VB) complex of Shank3Δ13-16 mice demonstrate reduced Ih current amplitude and correspondingly increased input resistance, negatively shifted resting membrane potential, and abnormal spike firing in both tonic and burst modes. Impressively, these changes closely resemble those of HCN2-/- TC neurons but not of the TC neurons from Shank3Δ4-9 mice, which lack exons 4-9 in the Shank3 gene (Shank3C still exists) and demonstrate moderate behavioural phenotypes. Additionally, Shank3 deficiency increases the ratio of excitatory/inhibitory balance in VB neurons but has a limited impact on the electrical properties of connected thalamic reticular (RTN) neurons. These results provide new understanding about the role of HCN channelopathy in mediating detrimental effects downstream from Shank3 deficiency.