Unsuspected periventricular leukomalacia in children with strabismus: a case series

Prevalence of the Infantile Strabismus Complex in Premature Children With and Without Periventricular Leukomalacia

PURPOSE

To determine whether rates of strabismus and associated visuomotor deficits differed among children with different severities of periventricular leukomalacia (PVL).

DESIGN

Retrospective, case-control study.

METHODS

Brain magnetic resonance images (MRI) obtained from 98 children aged ≥2 years were analyzed using a standardized scoring system: 67 of 98 had PVL (mean GA 31 weeks) and 31 of 98 did not have PVL (mean GA 29 weeks). Severity of PVL was scored as degree of damage to the posterior optic radiations and the splenium of the corpus callosum on MRI. Ophthalmologic examination data were collated to assess the prevalence of visuomotor deficits and the relationship to PVL severity (grades 1-3, mild to severe).

RESULTS

Infantile strabismus was documented in 61% of children with mild, 74% with moderate, and 88% with severe PVL (esotropia: exotropia ratio 3.5:1). Associated ocular motor deficits also increased systematically with PVL severity: latent ("fusion maldevelopment") nystagmus (20%, 47%, and 40%, respectively), dissociated vertical deviation (13%, 28%, and 30%), and nasotemporal pursuit/optokinetic nystagmus asymmetry (23%, 38%, and 54%). Additionally, the prevalence of retrograde optic neuropathy increased with PVL severity (5%, 26%, and 38%). The prevalence of each of these signs was substantially lower in children who had no PVL.

CONCLUSIONS

Children who suffer PVL are likely to develop the deficits of the infantile strabismus complex. The deficits tend to increase systematically as a function of PVL severity. These findings provide evidence that infantile strabismus is linked to perinatal damage to cerebral vergence and gaze pathways.

Clinical Spectrum of Ocular and Visual Dysfunction in Children with Periventricular Leukomalacia: A Need for an Interdisciplinary Approach

The study aimed to evaluate the ocular motility and visual and optic disc abnormalities in children diagnosed with periventricular leukomalacia (PVL). A retrospective analysis was performed on 51 consecutive children who had ophthalmic symptoms and were diagnosed with PVL by using magnetic resonance imaging. The patients were assessed for visual function, strabismus, cycloplegic refraction, fundus examination, and if appropriate, spectral-domain optical coherence tomography and visual field testing were applied. The primary outcome measures were the prevalence and visual and ocular motility dysfunctions. Mean age was 5.72 ± 2.6 years (range = 1–12), median birth weight was 2,740 g (range = 1,240–3,460), and median gestational age was 34 weeks (range = 28–38). In total, 21 patients (39.6%) had neurological deficit, 11 (21.5%) had intellectual disability, and 19 (37.2%) had no neurological symptom. In the spherical equivalent refractive error and cylinder power analysis, 10 patients had ≥3.0 D myopia, 15 had ≥3.0 D hyperopia, and eight had ≥2.50 D astigmatism. Thirteen (25.4%) children had a best-corrected visual acuity between 20/40 and 20/20 for Snellen card, while 9 (17.6%) had strabismic amblyopia and 6 (11.7%) had anisometropic amblyopia. Manifest strabismus was present in 35 patients (68.6%); of whom 12 had esotropia (23.5%), 16 had exotropia (31.3%) and 6 had vertical deviation (11.7%). Manifest or latent nystagmus was detected in 14 patients (27.4%). In 28 patients (54.9%), there was optic nerve abnormality. Two patients had hypoplastic disc, 14 had optic disc pallor, 7 had large cupping, and 5 had total optic atrophy. Six subjects underwent reliable visual field (VF) examinations, and all six had abnormal VFs, with inferior fields being most affected. Ocular motility disorders, optic nerve abnormalities, VF defects, and low visual acuity are common findings in this cohort of PVL patients and maybe the only presenting signs of the disease. The recognition of the visual disabilities and implementation of early rehabilitation may have a significant benefit in these children.

Periventricular leukomalacia: an ophthalmic perspective

Periventricular leukomalacia (PVL) is a common magnetic resonance imaging (MRI) finding in cases of hypoxic ischemic encephalopathy. PVL, in MRI, is identified by the increased signal intensity of periventricular white matter on T2-weighted sequences which is more conspicuous in the posterior cortex. It occurs because of perinatal damage to the cerebral cortex. This insult is in the form of hypoxia, metabolic insults, prematurity, seizures, or infection. Periventricular area is most prone to damage owing to its immaturity and vascular supply. PVL is proven to affect vision in children. Depending on the area and cause of affection, PVL is associated with variable ophthalmic manifestations. It is known that visual function is closely linked to the overall neurodevelopment of a child. A multidisciplinary approach is required to promote the growth and development of these children, and in the midst of multiple disabilities, visual function should not be overlooked. A comprehensive knowledge of the ophthalmological presentation in the developing world can aid us in an early and accurate diagnosis and in intervention for better therapeutic recovery and rehabilitation of these children.

Predisposing Factors, Ophthalmic Manifestations, and Radiological Findings in Children With Cerebral Visual Impairment

PURPOSE

To describe predisposing factors, ophthalmic manifestations, and magnetic resonance imaging (MRI) findings in children with cerebral visual impairment.

METHODS

A retrospective cross-sectional analysis of patients younger than 16 years with neuroradiological and clinical evidence of retrogeniculate visual pathway pathology was performed. Detailed histories, ophthalmic examinations, and MRI findings were compiled and analyzed.

RESULTS

Of the 88 cases included in the study, the median age was 32 months (range: 1 to 180 months). Ante-natal history and preterm delivery was positive in 25.0% and 37.5% of patients, respectively. A simple myopic astigmatism was the most common refractive error. Accommodative anomalies were noted in 6 children.

CONCLUSIONS

The demographic trends found in the study were similar to those of developed nations, but the frequency of the predisposing factors varied. A comprehensive knowledge of cerebral visual impairment in the developing world can aid an earlier diagnosis, appropriate management, and the development of better rehabilitation teams. [J Pediatr Ophthalmol Strabismus. 2019;56(5):313-318.].

Genome-Wide Association Study Identifies a Susceptibility Locus for Comitant Esotropia and Suggests a Parent-of-Origin Effect

Purpose

To identify genetic variants conferring susceptibility to esotropia. Esotropia is the most common form of comitant strabismus, has its highest incidence in European ancestry populations, and is believed to be inherited as a complex trait.

Methods

White European American discovery cohorts with nonaccommodative (826 cases and 2991 controls) or accommodative (224 cases and 749 controls) esotropia were investigated. White European Australian and United Kingdom cohorts with nonaccommodative (689 cases and 1448 controls) or accommodative (66 cases and 264 controls) esotropia were tested for replication. We performed a genome-wide case-control association study using a mixed linear additive model. Meta-analyses of discovery and replication cohorts were then conducted.

Results

A significant association with nonaccommodative esotropia was discovered (odds ratio [OR] = 1.41, P = 2.84 × 10-09) and replicated (OR = 1.23, P = 0.01) at rs2244352 [T] located within intron 1 of the WRB (tryptophan rich basic protein) gene on chromosome 21 (meta-analysis OR = 1.33, P = 9.58 × 10-11). This single nucleotide polymorphism (SNP) is differentially methylated, and there is a statistically significant skew toward paternal inheritance in the discovery cohort. Meta-analysis of the accommodative discovery and replication cohorts identified an association with rs912759 [T] (OR = 0.59, P = 1.89 × 10-08), an intergenic SNP on chromosome 1p31.1.

Conclusions

This is the first genome-wide association study (GWAS) to identify significant associations in esotropia and suggests a parent-of-origin effect. Additional cohorts will permit replication and extension of these findings. Future studies of rs2244352 and WRB should provide insight into pathophysiological mechanisms underlying comitant strabismus.

Visuospatial skills, ocular alignment, and magnetic resonance imaging findings in very low birth weight adolescents

PURPOSE

To describe ocular alignment and stereoacuity in adolescents with very low birth weight (VLBW) in comparison with a matched control group and to investigate associations with white matter damage of immaturity (WMDI) and visuospatial skills in the VLBW group.

METHODS

Fifty-nine 15-year-old VLBW subjects and 55 age- and sex-matched controls with normal birth weight underwent examination, including measurement of ocular alignment using cover test and Maddox rod and cycloplegic refraction. Stereoacuity was assessed with the TNO test, best-corrected visual acuity with a Konstantin Moutakis letter chart, and visuospatial skills with the performance tests, defined as performance intelligence quotient (IQ), in the Wechsler Intelligence Scale for Children (WISC-III). All VLBW subjects underwent magnetic resonance imaging of the brain.

RESULTS

Ocular misalignment was significantly more common in the VLBW group than in the control group (22% compared with 4%; p = 0.004). Exophoria, subnormal stereoacuity, and subnormal performance IQ were significantly more common in the VLBW group than in the control group (p = 0.006, p = 0.011, and p = 0.015, respectively). Ocular misalignment was associated with WMDI (p = 0.035) and subnormal performance IQ (p = 0.020). Of the VLBW subjects with ocular misalignment, 69% had WMDI and/or subnormal performance IQ.

CONCLUSIONS

The VLBW adolescents had more visuospatial problems, lower stereoacuity, and more ocular misalignment than the control subjects. Ocular misalignment was associated with visuospatial deficiencies and/or WMDI in the VLBW group and was a better predictor for visuospatial deficits than WMDI.