Optic nerve hypoplasia, encephalopathy, and neurodevelopmental handicap

AFENet: Attention Fusion Enhancement Network for Optic Disc Segmentation of Premature Infants

Retinopathy of prematurity and ischemic brain injury resulting in periventricular white matter damage are the main causes of visual impairment in premature infants. Accurate optic disc (OD) segmentation has important prognostic significance for the auxiliary diagnosis of the above two diseases of premature infants. Because of the complexity and non-uniform illumination and low contrast between background and the target area of the fundus images, the segmentation of OD for infants is challenging and rarely reported in the literature. In this article, to tackle these problems, we propose a novel attention fusion enhancement network (AFENet) for the accurate segmentation of OD in the fundus images of premature infants by fusing adjacent high-level semantic information and multiscale low-level detailed information from different levels based on encoder-decoder network. Specifically, we first design a dual-scale semantic enhancement (DsSE) module between the encoder and the decoder inspired by self-attention mechanism, which can enhance the semantic contextual information for the decoder by reconstructing skip connection. Then, to reduce the semantic gaps between the high-level and low-level features, a multiscale feature fusion (MsFF) module is developed to fuse multiple features of different levels at the top of encoder by using attention mechanism. Finally, the proposed AFENet was evaluated on the fundus images of preterm infants for OD segmentation, which shows that the proposed two modules are both promising. Based on the baseline (Res34UNet), using DsSE or MsFF module alone can increase Dice similarity coefficients by 1.51 and 1.70%, respectively, whereas the integration of the two modules together can increase 2.11%. Compared with other state-of-the-art segmentation methods, the proposed AFENet achieves a high segmentation performance.

The spectrum of brain malformations and disruptions in twins

Twins have an increased risk for congenital malformations and disruptions, including defects in brain morphogenesis. We analyzed data on brain imaging, zygosity, sex, and fetal demise in 56 proband twins and 7 less affected co-twins with abnormal brain imaging and compared them to population-based data and to a literature series. We separated our series into malformations of cortical development (MCD, N = 39), cerebellar malformations without MCD (N = 13), and brain disruptions (N = 11). The MCD group included 37/39 (95%) with polymicrogyria (PMG), 8/39 (21%) with pia-ependymal clefts (schizencephaly), and 15/39 (38%) with periventricular nodular heterotopia (PNH) including 2 with PNH but not PMG. Cerebellar malformations were found in 19 individuals including 13 with a cerebellar malformation only and another 6 with cerebellar malformation and MCD. The pattern varied from diffuse cerebellar hypoplasia to classic Dandy-Walker malformation. Brain disruptions were seen in 11 individuals with hydranencephaly, porencephaly, or white matter loss without cysts. Our series included an expected statistically significant excess of monozygotic (MZ) twin pairs (22/41 MZ, 54%) compared to population data (482/1448 MZ, 33.3%; p = .0110), and an unexpected statistically significant excess of dizygotic (DZ) twins (19/41, 46%) compared to the literature cohort (1/46 DZ, 2%; p < .0001. Recurrent association with twin-twin transfusion syndrome, intrauterine growth retardation, and other prenatal factors support disruption of vascular perfusion as the most likely unifying cause.

Optic Nerve Hypoplasia and Crouzon Syndrome

Crouzon syndrome is the most common cause of syndromic craniosynostosis. The authors present a previously unreported association between Crouzon syndrome and optic nerve hypoplasia. A male infant was transferred to the center for treatment of respiratory distress. He was diagnosed as having dysmorphic features, a membranous choanal stenossi bilaterally, and bilateral optic nerve hypoplasia. Genetic testing confirmed a molecular diagnosis of Crouzon syndrome. He had a complicated course in relation to choanal stenosis management, and was discharged home at 10 weeks of age. Although uncommon in Crouzon syndrome, the association with optic nerve hypoplasia changes the initial work-up and the management of parental expectations. [J Pediatr Ophthalmol Strabismus. 2018;55:e45-e48.].

Optic nerve hypoplasia in children and adolescents; prevalence, ocular characteristics and behavioural problems

PURPOSE

To report prevalence, ocular characteristics and coexisting behavioural problems in children and adolescents with optic nerve hypoplasia (ONH), which is a common cause of visual impairment in children in western countries, often associated with neurological or endocrinological problems and where autism has been reported in severe cases with blindness.

METHODS

This is a population-based cross-sectional study of patients <20 years of age who had been diagnosed with ONH and lived in the county of Stockholm in December 2009. Ophthalmological assessments including fundus photographs with optic disc analyses were made. A questionnaire was used to screen for behaviour and development.

RESULTS

The prevalence of ONH in all living children <18 years of age in Stockholm was 17.3/100 000 with a prevalence of visual impairment (<0.3) of 3.9/100 000. In total, 66 patients, median age 9.3 years (0.6-19.4), 36 with bilateral and 30 with unilateral ONH, were included in the current study; 53 were re-examined clinically, group A, and 13 agreed to retrospective analyses of existing medical records, group B. Analyses of the optic discs were made in fundus photographs from 53 patients comparing a semi-automated (Retinal Size Tool) and a manual method (Zeki). There was a strong curvilinear correlation (r(S)  = -0.91 p < 0.0001 for both eyes). Behavioural problems were more common (p < 0.05) in bilateral ONH.

CONCLUSION

Optic nerve hypoplasia is a common ocular malformation with a prevalence of 17.3/100 000 children and adolescents <18 years of age in Stockholm. Unilateral ONH seems as common as bilateral.

Evaluation of optic nerve development in preterm and term infants using handheld spectral-domain optical coherence tomography

PURPOSE

To evaluate effects of prematurity on early optic nerve (ON) development and the usefulness of ON parameters as indicators of central nervous system (CNS) development and pathology.

DESIGN

Prospective, cross-sectional, longitudinal study.

PARTICIPANTS

Forty-four preterm infants undergoing retinopathy of prematurity (ROP) screening and 52 term infants.

METHODS

We analyzed ON from portable handheld spectral-domain optical coherence tomography (SD-OCT) images (Bioptigen, Inc, Research Triangle Park, NC) of 44 preterm and 52 term infants. The highest-quality ON scan from either eye was selected for quantitative analysis. Longitudinal analysis was performed at 31-36 weeks and 37-42 weeks postmenstrual age (PMA). Preterm ON parameters also were assessed for correlation with indicators of cognitive, language, and motor development and CNS pathology.

MAIN OUTCOME MEASURES

Vertical cup diameter (vCD), vertical disc diameter (vDD), vertical cup-to-disc ratio (vCDR), cup depth, and indicators of neurocognitive development and CNS pathology.

RESULTS

At 37-42 weeks PMA, preterm infants had larger vCD and vCDR than term infants (908 vs. 700 μm [P<0.001] and 0.68 vs. 0.53 μm [P<0.001], respectively), whereas cup depth and vDD were not significantly different. Longitudinal changes (n = 26 preterm eyes; mean interval, 4.7 weeks) in vDD and in vCDR were an increase of 74 μm (P = 0.008) and decrease of 0.05 (P = 0.015), respectively. In preterm infants (n = 44), periventricular leukomalacia was associated with larger vCD (1084 vs. 828 μm; P = 0.005) and vCDR (0.85 vs. 0.63; P<0.001), posthemorrhagic hydrocephalus was associated with shallower cup (331 vs. 456 μm; P = 0.030), and clinical magnetic resonance imaging was associated with larger vCDR (0.73 vs. 0.64; P = 0.023). In 23 preterm infants with Bayley Scales of Infant Development scores, larger vCDR was associated with lower cognitive scores (P = 0.049).

CONCLUSIONS

This is the first analysis of ON parameters in premature infants using SD-OCT. It demonstrated that by age of term birth, vCD and vCDR are larger in preterm infants who were screened for ROP than in term infants. In this prospective pilot study, ON parameters in these preterm infants associate weakly with CNS pathology and future cognitive development. Future prospective studies with larger numbers are necessary before further conclusions can be made.

Congenital abnormalities of the optic nerve: from gene mutation to clinical expression

Optic nerve malformations are common causes of congenital blindness and are recognized with increasing prevalence. The importance of identifying these malformations lies not only in determining the cause and level of visual impairment, but also in looking for associated treatable or life threatening systemic conditions. A number of genetic mutations have been identified in the development of optic disc anomalies, such as ones in PAX2 or PAX6. Recent advances in genetic testing like array comparative genomic hybridization allow the detection of microdeletions that were previously difficult or impossible to identify.

Prenatal determinants of optic nerve hypoplasia: review of suggested correlates and future focus

Optic nerve hypoplasia (ONH), a congenital malformation characterized by an underdeveloped optic nerve, is a seemingly epidemic cause of childhood blindness and visual impairment with associated lifelong morbidity. Although the prenatal determinants of ONH are unknown, early case reports have led to a longstanding speculation that risky health behaviors (e.g., prenatal use of recreational drugs, alcohol) are a likely culprit. There has yet to be a systematic review of the epidemiology of ONH to assess the common prenatal features that may help focus research efforts in the identification of likely prenatal correlates. A review of the past 50 years of epidemiologic research was conducted to examine the prenatal features linked with ONH and provide direction for future research. There are select prominent prenatal features associated with ONH: young maternal age and primiparity. Commonly implicated prenatal exposures (recreational or pharmaceutical drugs, viral infection, etc.) were rare or uncommon in large cohort studies of ONH and therefore unlikely to be major contributors to ONH. Familial cases and gene mutations are rare. The preponderance of young mothers and primiparity among cases of ONH is striking, although the significance is unclear. Recent research suggests a potential role for prenatal nutrition, weight gain, and factors of deprivation. With the rapidly increasing prevalence of ONH, future research should focus on investigating the relevance of young maternal age and primiparity and exploring the recently suggested etiologic correlates in epidemic clusters of ONH.

Optic nerve hypoplasia syndrome: a review of the epidemiology and clinical associations

OPINION STATEMENT

BACKGROUND

Optic nerve hypoplasia (ONH) has developed into a leading cause of congenital blindness. The frequently associated features of hypopituitarism and absent septum pellucidum were felt to have embryonic linkage as "septo-optic dysplasia" or "de Morsier's syndrome." More recent studies have suggested these associations are independent of one another. This review provides an assessment of the historical and recent evidence linking neuroradiologic, endocrinologic and developmental morbidity in patients with ONH. The prenatal risk factors, heritability, and genetic mutations associated with ONH are described.

RESULTS

Recognition of the critical association of ONH with hypopituitarism should be attributed to William Hoyt, not Georges de Morsier. De Morsier never described a case of ONH or recognized its association with hypopituitarism or missing septum pellucidum. Hypopituitarism is caused by hypothalamic dysfunction. This, and other more recently identified associations with ONH, such as developmental delay and autism, are independent of septum pellucidum development. Other common neuroradiographic associations such as corpus callosum hypoplasia, gyrus dysplasia, and cortical heterotopia may have prognostic significance. The predominant prenatal risk factors for ONH are primiparity and young maternal age. Presumed risk factors such as prenatal exposure to drugs and alcohol are not supported by scrutiny of the literature. Heritability and identified gene mutations in cases of ONH are rare.

CONCLUSION

Children with ONH require monitoring for many systemic, developmental, and even life-threatening problems independent of the severity of ONH and presence of brain malformations including abnormalities of the septum pellucidum. "Septo-optic dysplasia" and "de Morsier's syndrome" are historically inaccurate and clinically misleading terms.

Reappraisal of the optic nerve hypoplasia syndrome

BACKGROUND

Optic nerve hypoplasia (ONH) has been described as an increasingly prevalent cause of congenital blindness. Its association with hypopituitarism and absent septum pellucidum has been recognized for more than 40 years as "septo-optic dysplasia" or "de Morsier syndrome." More recent studies have suggested that these associations are independent of one another. This review was designed to assess the historical and recent evidence for associations of neuroradiologic, endocrinologic, and developmental problems in patients with ONH.

EVIDENCE ACQUISITION

Historical and contemporary literature review.

RESULTS

The medical literature does not support the notion that Georges de Morsier ever described a case of ONH or recognized its association with hypopituitarism or missing septum pellucidum. Recognition of the critical association of ONH with hypopituitarism should be attributed to William Hoyt. Hypopituitarism and other more recently identified associations with ONH, such as developmental delay, hypothalamic dysfunction, and autism, are independent of septum pellucidum development. Other common neuroradiographic associations, such as corpus callosum hypoplasia, gyrus dysplasia, and cortical heterotopia, may have prognostic significance.

CONCLUSIONS

Children with ONH need to be monitored for many systemic, developmental, and even life-threatening problems independent of the status of the septum pellucidum. "Septo-optic dysplasia" and "de Morsier syndrome" are historically inaccurate and clinically misleading terms that should be abandoned.

Septo-optic dysplasia

Septo-optic dysplasia (SOD), also referred to as de Morsier syndrome, is a rare congenital condition, characterized by two of the classic triad features: midline brain abnormalities, optic nerve hypoplasia (ONH) and pituitary endocrine dysfunction. We report 5 children with SOD, originally referred to be evaluated due to short stature, who also presented bilateral optic nerve hypoplasia, nystagmus and development delay. In 4 of the patients, we identified neuroimaging abnormalities of the hypothalamo-pituitary axis such as anterior pituitary hypoplasia (3/5), ectopic posterior pituitary (4/5), thin or absent stalk (3/5) and empty sella (1/5). We also encountered diverse pituitary deficiencies: growth hormone (3/5), adrenocorticotropic hormone (3/5), thyroid-stimulating hormone (2/5) and antidiuretic hormone (1/5). Only one child presented intact pituitary function and anatomy. Although rare, SOD is an important cause of congenital hypopituitarism and it should be considered in children with optic nerve hypoplasia or midline brain abnormalities for early diagnosis and treatment.

Optic nerve hypoplasia in North America: a re-appraisal of perinatal risk factors

PURPOSE

The purpose of this study is to describe and clarify the birth and prenatal characteristics of a large cohort of children with optic nerve hypoplasia.

METHODS

This is a descriptive report of 204 patients aged

RESULTS

Birth characteristics were unremarkable for birthweight and gestation, but significant for increased frequency of caesarean delivery and fetal and neonatal complications. Young maternal age and primaparity were dominating maternal features. Preterm labour, gestational vaginal bleeding, low maternal weight gain and weight loss during pregnancy were prevalent.

CONCLUSIONS

These findings confirm young maternal age and primaparity as associated risk factors, challenge many other suggested factors such as alcohol and drug abuse, and introduce potentially significant prenatal characteristics such as maternal weight loss and early gestational vaginal bleeding as aetiological correlates.

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Key Words

• aetiology
• de morsier syndrome
• optic nerve hypoplasia
• perinatal
• prenatal
• septo-optic dysplasia

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MESH Headings

• Birth Weight
• Child, Preschool
• Eye Abnormalities/epidemiology
• Female
• Gestational Age
• Humans
• Infant
• Infant, Newborn
• Infant, Premature
• Male
• Maternal Age
• North America/epidemiology
• Optic Nerve/abnormalities
• Parity
• Pregnancy
• Prospective Studies
• Registries/statistics & numerical data
• Risk Factors
• Sweden/epidemiology

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Grants

• M01 RR000043-44 NCRR NIH HHS
• UL1 RR031986 NCRR NIH HHS
• M01 RR00043 NCRR NIH HHS
• UL1 RR031986-01 NCRR NIH HHS
• M01 RR000043 NCRR NIH HHS

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Affiliation(s)

Pamela Garcia-Filion The Vision Center at Childrens Hospital Los Angeles, and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA.
Cassandra Fink
Mitchell E Geffner
Mark Borchert

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Neuroradiographic, endocrinologic, and ophthalmic correlates of adverse developmental outcomes in children with optic nerve hypoplasia: a prospective study

BACKGROUND

Developmental delay has been reported to occur with optic nerve hypoplasia, a leading cause of pediatric blindness, but has not been systematically examined for its prevalence and correlation with associated pathologies of optic nerve hypoplasia.

OBJECTIVE

The purpose of this study was to determine the developmental outcomes of children with optic nerve hypoplasia and the correlation of development with neuroradiographic, endocrinologic, and ophthalmic findings.

METHODS

We conducted a prospective analysis of 73 subjects diagnosed with optic nerve hypoplasia at <36 months of age for developmental outcomes at 5 years of age. Subjects underwent neuroradiographic imaging, endocrinologic testing and examination, and ophthalmologic examination; developmental outcomes were assessed by using the Battelle Developmental Inventory.

RESULTS

At 5 years of age, developmental delay was present in 71% of subjects with optic nerve hypoplasia. Of patients with unilateral (18%) and bilateral optic nerve hypoplasia, 39% and 78%, respectively, experienced developmental delay. Corpus callosum hypoplasia and hypothyroidism were significantly associated with poor outcome in all of the developmental domains and an increased risk of delay. Absence of the septum pellucidum was not associated with adverse development. Six subjects had neither a neuroradiographic nor an endocrinologic abnormality, and of those, 4 were developmentally delayed.

CONCLUSIONS

These prospective data confirm the significant association of developmental delay with optic nerve hypoplasia and identify corpus callosum hypoplasia and hypothyroidism as strong correlates. A diagnosis of optic nerve hypoplasia warrants neuroradiographic and endocrinologic testing for risk factors of delay and developmental assessments for early intervention planning.

[Optic nerve hypoplasia associated to ectopic neurohypophysis]

Hypoplasia of the optic nerve is a rare congenital anomaly of unknown etiology that is a frequent cause of blindness in children. It can present in isolation or associated to other malformations of the central nervous system. Magnetic resonance is the technique of choice for the study of this condition; it enables both the hypoplasia of the nerve and the possible associated malformations to be demonstrated. We present a case of optic nerve hypoplasia associated to ectopic neurohypophysis.

RetCam image analysis of optic disc morphology in premature infants and its relation to ischaemic brain injury

AIMS

To assess optic disc characteristics in premature infants with and without ischaemic brain injury and to evaluate the role of optic disc morphology in dating the injury.

METHODS

RetCam fundal images, cranial ultrasounds and magnetic resonance imaging (MRI) of 109 premature infants were analysed. The study cohort was divided into subgroups depending on the presence or absence of periventricular leucomalacia (PVL) and intraventricular haemorrhage (IVH). The control group consisted of infants with normal neuroimaging at term and 2 years of age. Using the image analysis software of the RetCam, optic disc diameter (ODD), optic disc area (ODA), and optic cup area (OCA) were measured at 33-34 weeks gestational age. As serial cranial ultrasonography had been performed, it was possible to date the brain injury in those infants with periventricular white matter (PVWM) damage.

RESULTS

Although there was a trend towards reducing ODD, ODA, and OCA with increasing severity of IVH, only the IVH 4 group differed significantly from the controls for these parameters (p = 0.002, p = 0.02, and p = 0.04, respectively). 44.4% of infants with grade 4 IVH had small discs. Only one patient had a large cup in a normal sized disc; this patient had IVH 4. In patients with PVWM damage, the median time of insult was 27 weeks in those with small discs and 28 weeks in those with normal discs. This difference was not significant (p = 0.23).

CONCLUSIONS

Premature infants with IVH 4 have an increased incidence of optic nerve hypoplasia. We found no association between disc morphology and timing of brain injury.

Combined trabeculotomy and trabeculectomy in advanced primary developmental glaucoma with corneal diameter of 14 mm or more

PURPOSE

To report the safety and efficacy of combined trabeculotomy and trabeculectomy (CTT) in advanced primary developmental glaucoma with corneal diameter 14 mm or more.

PATIENTS AND METHODS

A total of 74 (121 eyes) consecutive patients aged 3 days-100 months (median, 10 months) with advanced developmental glaucoma were included. Primary CTT was performed by a single surgeon at a tertiary eye care centre in India over a 13-year period. The main outcome measures were changes in and final levels of intraocular pressure (IOP), corneal clarity, visual acuity, and refractive status.

RESULTS

Mean preoperative IOP was 29.4+/-7.6 mmHg (range, 10-56 mmHg) and mean postoperative IOP was 15.5+/-6.6 mmHg (range, 6-38 mmHg) (P<0.0001) with percentage reduction of 44.5+/-27.1. Kaplan-Meier survival analysis revealed 3-, 6-, 9-, 12-, 24-, 48-, and 72-month success rates of 86.5, 80.5, 78.1, 75.5, 71.1, and 60.5%, respectively. Majority (80.5%) of the patients were myopes with mean spherical equivalent of 5.8+/-4.5D (range, 0.75-22.0D). Using various age-appropriate testing procedures, at the final follow-up visit, 14 patients (41.2%) had age-appropriate normal visual acuity and 20 patients (58.8%) had subnormal visual acuity. Best-spectacle-corrected visual acuity of > or =20/60 was achieved in seven patients (26.9%). There were no sight-threatening intraoperative and postoperative complications.

CONCLUSION

CTT is safe and effective in patients with advanced primary developmental glaucoma. It offers good IOP control with a low complication rate, with about one-third of patients achieving a visual acuity of 20/60 or better.

Congenital disorders of the optic nerve: excavations and hypoplasia

The principal congenital abnormalities of the optic disc that can significantly impair visual function are excavation of the optic disc and optic nerve hypoplasia. The excavated optic disc abnormalities comprise optic disc coloboma, morning glory syndrome, and peripapillary staphyloma. Optic nerve hypoplasia manifests as a small optic nerve, which may or may not be accompanied by a peripapillary ring (the double ring sign). In addition, the optic disc cupping, which occurs as a sequel to some cases of periventricular leucomalacia, can arguably be classified as a type of optic nerve hypoplasia. All of these conditions can be unilateral or bilateral and can impair visual function mildly or severely. It is essential that children with poor vision due to any of these conditions are managed by treating refractive errors, giving occlusion therapy in selected cases, and optimising the conditions at home and at school in an attempt to ensure that impaired vision does not impede development or education.

Septo-optic dysplasia, subglottic stenosis and skeletal abnormalities: a case report

We report a girl with septo-optic dysplasia in association with subglottic stenosis, sagittal craniosynostosis, osteoporosis and dental anomalies. It is uncommon for patients with septo-optic dysplasia to have multiple, extra-cranial malformations. A number of differential diagnoses were considered in this case, including Cole-Carpenter syndrome, Pfeiffer syndrome and osteoglophonic dwarfism. However, none can account for all the abnormalities seen. We therefore believe that this is a previously unreported, but highly distinctive, phenotype.

Optic nerve hypoplasia: Risk factors and epidemiology

OBJECTIVES

To study the epidemiology of optic nerve hypoplasia.

DESIGN AND METHODS

Children with optic nerve hypoplasia and visual impairment were identified through the Swedish Register of Visually Impaired Children. Pre- and perinatal characteristics were obtained from the Medical Birth Registry and by scrutinizing pregnancy and delivery records. Clinical characteristics of children with optic nerve hypoplasia are described. The following risk factors were studied: maternal age, parity, maternal smoking, gestational duration, birth weight, delivery method, Apgar score, maternal disease during pregnancy, drugs used in early pregnancy.

RESULTS

Young maternal age, first parity, maternal smoking, preterm birth and factors associated with preterm birth were risk factors for optic nerve hypoplasia. There was an indicated association with the use of fertility drugs and antidepressant drugs.

CONCLUSIONS

Optic nerve hypoplasia is apparently associated not only with other anomolies, notably of the central nervous system, but also with signs of general disturbance in fetal development.

Familial orofaciodigital syndrome type I revealed by ultrasound prenatal diagnosis of porencephaly

Porencephaly is a rare central nervous system (CNS) abnormality that can be caused by an intraparenchymal destructive process or a developmental defect. Here we report on a prenatal ultrasound diagnosis of complex CNS abnormalities including agenesis of the corpus callosum, agenesis of the cerebellar vermis, bilateral hydrocephaly, and bilateral porencephaly in fetus at 33 weeks' gestation. The diagnosis of familial orofaciodigital syndrome type I (OFD I) was raised after fetal autopsy, clinical examination of the family, and the X-linked dominant inheritance pattern. This is the fourth report of porencephaly in association with OFD I. We discuss the difficulties in genetic counselling since OFD I shows variable expressivity of the phenotypic features. Furthermore, we emphasize the importance of a detailed ultrasound examination after a prenatal diagnosis of porencephaly.

Optic nerve morphology may reveal adverse events during prenatal and perinatal life--digital image analysis

OBJECTIVE

To evaluate optic nerve morphology in children with various conditions caused by adverse events during prenatal and/or perinatal life and to investigate whether optic nerve morphology can reveal brain lesions associated with these conditions, as well as provide insight into the etiology and timing of the prenatal and perinatal damage.

METHODS AND PATIENTS

A digital image analysis technique was used to analyze fundus photographs. One hundred healthy Swedish individuals of various ages from childhood to adolescence constituted a reference group. The following patient groups were chosen to represent various clinical conditions affecting the newborn or fetus at different stages of development: children born preterm (N = 39), children with fetal alcohol syndrome (FAS [N = 16]), children with periventricular leukomalacia (PVL [N = 17]), and children with septo-optic dysplasia (SOD [N = 6]).

RESULTS

Preterm children without known brain lesions demonstrated normal optic disk morphology but abnormal retinal vascular pattern; children born preterm with an acquired brain lesion late in gestation (PVL) demonstrated normal disk size with enlarged cups in addition to the abnormal vascular pattern. Children with prenatal alcohol exposure (FAS) had a subnormal optic disk area with increased tortuosity of both arteries and veins, whereas children born at term with an early acquired brain lesion (SOD) had a markedly reduced optic disk area with isolated tortuosity of the retinal veins.

CONCLUSIONS

Evaluation of optic nerve morphology, by digital image analysis, demonstrated that differences in ocular fundus morphology were correlated with differences in etiology and timing of the adverse event occurring in prenatal and perinatal life. In addition, digital image analysis may be a helpful tool for understanding variations in optic nerve and retinal vessel morphology and their relationship with central nervous pathology.

The clinical and morphologic spectrum of optic nerve hypoplasia

PURPOSE

The purpose of this study was to characterize the clinical and morphologic spectrum of all children referred for optic nerve hypoplasia to a tertiary referral hospital in Sweden during a 9-year period.

SUBJECTS AND METHODS

A retrospective review was undertaken of the charts of 117 children (age range, 0.25-16 years), treated at the Children's Hospital, Göteberg between 1988 and 1996, after the diagnosis of optic nerve hypoplasia. Ocular fundus morphologic condition was evaluated by digital image analysis of fundus photographs in 50 children, and neuroimaging was performed in 57 children.

RESULTS

Of the 117 children with optic nerve hypoplasia, 66 (56%) were boys and 51 (44%) were girls. Preterm birth occurred in 24 (20%), and 14 (12%) were born small for gestational age. Additional diagnoses, such as fetal alcohol syndrome, septo-optic dysplasia, perinatal adverse events, and neuropsychiatric disorders, were made in 88%; 7% had unilateral optic nerve hypoplasia. Most of the children had small optic disc, cup, and neuroretinal rim areas, as well as retinal vascular abnormalities; 75% were visually impaired, and a high incidence of nystagmus and strabismus was found among these children.

CONCLUSION

This study indicates that optic nerve hypoplasia has a wide clinical and morphologic spectrum and is associated with a broad range of disorders of the central nervous system. It is suggested that differences in the etiology and timing of the lesion as well as associated lesions may explain this spectrum of optic nerve hypoplasia in children.

Neuroimaging in children with congenital disorders of the peripheral visual system

The study investigates the neurological substrate in children with congenital disorders of the peripheral visual system (CDPVS), i.e. disorders of the anterior visual pathways and the globe. The design is retrospective; brain MRI and/or CT scans were traced and reviewed for 79 of 254 children with CDPVS on our database. The neuroradiological findings were considered in the context of degree of visual impairment (profound [PVI] and severe [SVI]), developmental outcome (setback and non-setback), and mode of imaging (MRI and CT). Scans were abnormal in 40 of 79 (51%) children; 23 of 40 (58%) had more than one lesion; and in some children lesions not previously reported were found. The number of abnormalities per child was significantly higher in the PVI than the SVI group (P<0.05); the level of significance varied according to the method of scanning (MRI, P<0.001; CT, ns). Seven children were known to have had developmental setback; significantly more brain abnormalities per child were found in the group with setbacks than in the group without (P<0.001). Eighty-six percent (24 of 28) of MRI compared with 38% (22 of 58) of CT scans were abnormal. MRI detected more lesions per child than CT (P< 0.001). Thus, a significant amount of brain pathology occurs in children with CDPVS. The number of lesions varies directly with degree of visual impairment and both correlate with developmental outcome. As brain pathology will be only one of many factors influencing developmental progress in visually impaired children, prospective multifactorial studies of the CDPVS population, which include MRI studies of the neurological substrate, will be required to clarify the latter.

The clinical, neuroradiographic, and endocrinologic profile of patients with bilateral optic nerve hypoplasia

PURPOSE

The purpose of the study was to expand on ophthalmologic and endocrinologic data and report the neuroimaging findings of 35 patients with bilateral optic nerve hypoplasia (BONH).

METHODS

A retrospective chart review of 35 children with BONH was conducted. Data on visual acuity, refractive error, and presence of nystagmus and strabismus were collected. Twenty-six children underwent full-endocrinologic evaluation and magnetic resonance imaging or computed tomography scanning.

RESULTS

The male:female ratio was 2:1. Ten percent of eyes had visual acuity of 20/60 or better, whereas 34% had no light perception. Eighty-six percent of eyes had acuity less than 20/200, and 80% of patients were legally blind. Most patients (86%) had nystagmus or strabismus or both. Forty-six percent had absence of the septum pellucidum and corpus callosum on neuroimaging. Twenty-seven percent of patients had endocrinologic abnormalities, with growth hormone deficiency being the most common. Panhypopituitarism occurred in 11.5% of children.

CONCLUSIONS

Although the visual prognosis of children with BONH generally is poor, 10% of such patients have excellent acuity. In contrast to previous reports, endocrine abnormalities were seen in only one quarter of patients, and the full-blown deMorsier syndrome (septo-optic dysplasia with panhypopituitarism) was seen in only 11.5% of patients with BONH.

Causes of blindness and severe visual impairment in children in Chile

Three hundred and eighteen of 421 children (76 per cent) registered in Chile's 10 schools for the blind were examined. 84 per cent of these had severe visual loss (severe visual impairment or blindness), which was attributable to hereditary factors in 29.6 per cent, intra-uterine factors in 8.2 per cent, perinatal factors in 22.5 per cent and childhood factors in 11.2 per cent. The aetiology could not be determined in 28.5 per cent. Retinopathy of prematurity (ROP) accounted for 17.6 per cent of all children with severe visual loss; analysis of data by age-group suggested that ROP is becoming an increasingly important cause of blindness. It is estimated that one-half of the children with severe visual loss in Chile have avoidable causes of blindness. The findings are discussed in the light of possible control strategies.

Electrophysiologic alterations in patients with optic nerve hypoplasia

The clinical and electrophysiologic data (electroretinograms and visual evoked potentials) were studied in 45 patients with optic nerve hypoplasia. The patients were divided into three fairly distinct groups on the basis of their electrophysiologic alterations. Group 1 consisted of 13 patients with almost extinguished visual evoked potentials and with mild electroretinographic alterations. These were the cases that are traditionally recognized as optic nerve hypoplasia. The serious visual impairment in these cases was accompanied by various developmental ophthalmologic and nonophthalmologic abnormalities. Group 2 included 26 patients without any significant visual evoked potential or electroretinographic alterations, but with overt funduscopic signs of optic nerve hypoplasia. These patients were consistently suffering from strabismus and/or amblyopia. The visual functions based on visual evoked potential and electroretinographic recordings could be fairly normal apart from a pathologic ophthalmoscopic picture characteristic of optic nerve hypoplasia. Group 3 included six patients with abnormal albeit well-recordable visual evoked potentials and subnormal or negative-type electroretinograms that suggested an accompanying retinal disease. This finding seems to prove that a subset of patients with optic nerve hypoplasia with nystagmus may have a primary retinal abnormality. Our study provides further evidence that optic nerve hypoplasia is not a uniform disease entity.

Follow-up study on premature infants with and without retinopathy of prematurity

The ocular complications in population of 131 premature infants, with and without retinopathy of prematurity (ROP) are reported. An increased incidence of strabismus (20% with ROP and 25% without ROP) and myopia (27.5% with ROP and 8.8% without ROP) was shown. Significant visual loss occurred in 10.7% overall, increasing to 35% with stage 3 disease and 100% with stage 4. With the increased survival rate of premature infants, the relevance to future management of this expanding group of young people is considered.