Clinical Feature Analysis of Congenital Optic Nerve Abnormalities

Clinical features of strabismus in patients with congenital optic disc anomaly

Purpose

To investigate the clinical features of strabismus in patients with congenital optic disc anomaly and compare and analyze the characteristics of patients who showed changes in the strabismus pattern with those who did not.

Methods

Medical records of the patients who were diagnosed with both strabismus and congenital optic disc anomaly and followed-up for ≥1 year were reviewed retrospectively. Clinical characteristics and ophthalmic features at the initial visit and final follow-up were assessed. Patients with a change in the direction of strabismus or a difference of >10 prism diopters in the deviation angle during the follow-up period were allocated to the changed group. The remaining patients were assigned to the unchanged group. The clinical characteristics of the two groups were compared.

Results

Twenty-eight patients (15 boys) were included (mean age, 39.0 months; range, 5–150 months). Three (10.7%) patients were born preterm and four (14.3%) had other underlying systemic disease. Sixteen (57.1%) patients had exotropia, and 12 (42.9%) had esotropia. Concurrent vertical strabismus was present in three (10.7%) patients. Strabismus features changed in 14 (50.0%, changed group) patients and remained unchanged in 14 (50.0%, unchanged group) patients. Age, sex, and laterality did not differ between groups. Preterm birth history (n = 3) and combined systemic disease (n = 4) were only observed in the changed group (p = 0.111 and p = 0.049, respectively).

Conclusions

Considering the possibility of changes in strabismic features, close monitoring of patients with strabismus combined with congenital disc anomaly is essential, particularly in those with preterm birth history or underlying systemic conditions.

Whole genome sequencing unveils genetic heterogeneity in optic nerve hypoplasia

Optic nerve hypoplasia (ONH) is a congenital malformation with a reduced number of retinal ganglion cell axons in a thin optic nerve. It is a common cause of visual impairment in children and ONH is associated with neurodevelopmental disorders, pituitary hormone deficiencies, and brain malformations. In most cases, the aetiology is unknown, but both environmental factors and genetic causes have been described. This study aimed to identify genetic variants underlying ONH in a well-characterised cohort of individuals with ONH. We performed array comparative genomic hybridization and whole genome sequencing in 29 individuals with ONH. Rare variants were verified by Sanger sequencing and inheritance was assessed in parental samples. We identified 11 rare single nucleotide variants (SNVs) in ten individuals, including a homozygous variant in KIF7 (previously associated with Joubert syndrome), a heterozygous de novo variant in COL4A1 (previously described in an individual with porencephaly), and a homozygous variant in COL4A2. In addition, one individual harboured a heterozygous variant in OPA1 and a heterozygous variant in COL4A1, both were inherited and assessed as variants of unknown clinical significance. Finally, a heterozygous deletion of 341 kb involving exons 7-18 of SOX5 (associated with Lamb-Schaffer syndrome) was identified in one individual. The overall diagnostic yield of pathogenic or likely pathogenic variants in individuals with ONH using whole genome sequencing was 4/29 (14%). Our results show that there is a genetic heterogeneity in ONH and indicate that genetic causes of ONH are not rare. We conclude that genetic testing is valuable in a substantial proportion of the individuals with ONH, especially in cases with non-isolated ONH.

High prevalence of pituitary hormone deficiency in both unilateral and bilateral optic nerve hypoplasia

AIM

This study examined the prevalence of neurological impairment and pituitary hormone deficiency (PHD) in patients with unilateral and bilateral optic nerve hypoplasia (ONH).

METHODS

A population-based cross-sectional cohort study of 65 patients (51% female) with ONH was conducted in Stockholm. Of these were 35 bilateral and 30 unilateral. The patients were below 20 years of age, living in Stockholm in December 2009 and found through database searching. The median age at the analysis of the results in January 2018 was 16.1 years (range 8.1-27.5 years). Neurological assessments and blood sampling were conducted, neuroradiology was reviewed and growth curves were analysed. Diagnoses of PHDs were based on clinical and biochemical evidence of hormone deficiency.

RESULTS

Neurological impairments were identified in 47% of the patients and impairments in gross and fine motor function were more prevalent in bilateral ONH (p < 0.001). In addition, 9% had cerebral palsy and 14% had epilepsy. The prevalence of PHD was 29 and 19% had multiple PHD.

CONCLUSION

Children with ONH had a high risk of neurological impairment, especially in bilateral disease. Both unilateral and bilateral ONH signified an increased prevalence of PHD and all these children should be endocrinologically followed up until completed puberty.

Children with optic nerve hypoplasia face a high risk of neurodevelopmental disorders

AIM

Optic nerve hypoplasia (ONH) is a congenital ocular malformation that has been associated with neurodevelopmental disorders, but the prevalence in unilateral disease and less severe visual impairment is unknown. We studied intellectual disability and autism spectrum disorders (ASDs) in patients with ONH.

METHODS

This was a population-based cross-sectional cohort study of 65 patients (33 female) with ONH below 20 years of age, living in Stockholm in December 2009, with data analysed in January 2016. Of these 35 were bilateral and 30 were unilateral. Neurodevelopmental disorders were diagnosed or confirmed by neurological assessments, the Five to Fifteen parent questionnaire and reviewing previous neuropsychological investigations or conducting neuropsychological tests.

RESULTS

Bilateral ONH patients had lower mean full scale intelligence quotient scores than unilateral patients (84.4 and 99.4, respectively, p = 0.049). We assessed intellectual disability in 55 eligible patients, and it was more common in patients with bilateral ONH (18 of 32, 56%) than unilateral ONH (two of 23, 9%, p < 0.001). ASDs were diagnosed in seven of 42 (17%) patients.

CONCLUSION

Children with bilateral ONH had a high risk of neurodevelopmental disorders, especially intellectual disability. The risk was lower in unilateral ONH, but the levels of neurodevelopmental disorders warrant screening of both groups.

Morning glory disc anomaly with an ipsilateral enlargement of the optic nerve pathway

PURPOSE

To report three patients with an unilateral morning glory disc anomaly in association with an ipsilateral mild thickening of the optic nerve.

METHODS

Three children with a morning glory disc anomaly underwent a magnetic resonance imaging (MRI) of the brain. Ophthalmological, genetic and MRI findings at follow-up are reported. A literature search on the association of morning glory anomaly in association with optic nerve glioma is reported.¹ RESULTS: Three children with an unilateral morning glory anomaly and ipsilateral poor visual acuity were found to have an ipsilateral mild optic nerve enlargement on brain MRI. At serial MRI scanning, there was no progression of this finding.

CONCLUSIONS

The morning glory disc anomaly is a rare congenital malformation of the optic disc. It can be associated with central nervous system abnormalities. The association with an optic nerve glioma has been described once before.¹ Our three cases confirm the possible association between a morning glory disc anomaly and an ipsilateral optic nerve enlargement. Serial MRI showed no growth at follow-up. The awareness of this association by the ophthalmologists is important.

Bilateral optic disc pathologies as an accompanying feature of comitant strabismus in children

PURPOSE

To describe and report accompanying bilateral optic disc pathologies in children with comitant strabismus.

METHODS

Twenty-eight patients (16 female, 12 male) aged between 1 and 12 years who had comitant strabismus and bilateral optic disc pathologies were included in the study. Visual acuity, refractive errors, amount of deviation and types of optic disc pathologies were all recorded. Each patient underwent complete neurological and ophthalmological examination.

RESULTS

Of the 28 patients, 14 (50.0%) had esotropia and 14 (50.0%) had exotropia. The mean age was 4.18 ± 3.03 years. The mean deviation angle was 35.30 ± 13.26 prism diopters (PD) (20-70 PD). Optic atrophy as being the most common pathology was found in nine (32.1%) patients. Six (21.4%) patients had temporal disc pallor, six (21.4%) patients had optic nerve hypoplasia, and seven (25%) patients had other optic disc anomalies (tilted disc, megalodisc, disc coloboma, peripapillary staphyloma). Optic disc pathologies were found to be isolated in 12 patients. Nine of 13 patients with congenital optic disc pathologies had esotropia, whereas 10 of 15 patients with optic atrophy or optic disc pallor had exotropia.

CONCLUSION

Comitant strabismus in children can be associated with congenital or acquired optic disc pathologies. It is worthy of note that esotropia was more common in patients with congenital optic disc pathologies, whereas exotropia was more frequent in patients with optic atrophy or optic disc pallor. The findings of the present study show that complete ophthalmological examination including fundus evaluation should be carried out in all patients with strabismus even though the cause of ocular misalignment is obvious.

Association of refractive error with optic nerve hypoplasia

PURPOSE

To evaluate the association of refractive error with optic nerve hypoplasia (ONH).

METHODS

A total of 30 ONH subjects were recruited and underwent comprehensive eye exams. Refractive error data from this group was compared to data from a group of 3232 non-ONH subjects from the same facility. Spherical equivalent was calculated to assess refractive error. Multiple logistic regression was used to evaluate the relationship between ONH and refractive error while controlling for age, race, and gender.

RESULTS

The prevalence of hyperopia (≥+1.00 D), myopia (<-0.75 D), and anisometropia (≥1.00 D) was higher in ONH subjects than in controls. ONH subjects were 9.1 times more likely to be hyperopic than emmetropic (OR = 9.1, 95% CI = 2.9-28.4, p < 0.001) and 3.8 times more likely to be myopic than emmetropic (OR = 3.8, 95% CI = 1.2-11.5, p = 0.02). Unilateral ONH subjects were 10.0 times more likely to have anisometropia than controls (OR = 10.0, 95% CI = 3.9-25.6, p < 0.0001). Bilateral ONH subjects were 3.8 times more likely to have anisometropia than controls (OR = 3.8, 95% CI = 1.1-12.7, p = 0.03).

CONCLUSIONS

Optic nerve hypoplasia subjects were more likely than control subjects to exhibit significant refractive errors, particularly hyperopia. Anisometropia tended to be more likely to occur in subjects with unilateral ONH than in bilateral ONH. Based on our findings, we recommend that clinicians perform a comprehensive eye examination on all patients with ONH and prescribe for existing refractive error when visual acuity or general visual function can realistically be improved.

Size of the intracranial optic nerve and optic tract in neonates at term-equivalent age at magnetic resonance imaging

BACKGROUND

The expected MRI-based dimensions of the intracranial optic nerve and optic tract in neonates are unknown.

OBJECTIVE

To evaluate the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age using MRI.

MATERIALS AND METHODS

We retrospectively analyzed brain MRI examinations in 62 infants (28 boys) without intracranial abnormalities. The images were obtained in infants at term-equivalent age with a 1.5-tesla MRI scanner. We measured the widths and heights of the intracranial optic nerve and optic tract and calculated the cross-sectional areas using the formula for an ellipse.

RESULTS

The means ± standard deviation of the width, height and cross-sectional area of the intracranial optic nerve were 2.7 ± 0.2 mm, 1.7 ± 0.2 mm and 3.5 ± 0.5 mm(2), respectively. The width, height and cross-sectional area of the optic tract were 1.5 ± 0.1 mm, 1.6 ± 0.1 mm and 2.0 ± 0.2 mm(2), respectively. Using univariate and multivariate analyses, we found that postmenstrual age showed independent intermediate positive correlations with the width (r = 0.48, P < 0.01) and cross-sectional area (r = 0.40, P < 0.01) of the intracranial optic nerve. The lower bounds of the 95% prediction intervals for the width and cross-sectional area of the intracranial optic nerve were 0.07 × (postmenstrual age in weeks) - 0.46 mm, and 0.17 × (postmenstrual age in weeks) - 4.0 mm(2), respectively.

CONCLUSION

We identified the sizes of the intracranial optic nerve and optic tract in neonates at term-equivalent age. The postmenstrual age at MRI independently positively correlated with the sizes.

Morning Glory Syndrome with Carotid and Middle Cerebral Artery Vasculopathy

PURPOSE

To report a case of incidental asymptomatic atypical morning glory syndrome (MGS) with concomitant ipsilateral carotid and middle cerebral dysgenesis.

CASE REPORT

A 6-year-old child was discovered to have incidental findings of MGS, with atypia. All visual functions were normal including vision and stereopsis. Neuroimaging revealed ipsilateral carotid and middle cerebral vascular narrowing without associated collateral vessels or cerebral ischemia commonly seen in Moyamoya disease. Subsequent annual examinations have been stable, without signs of progression.

CONCLUSIONS

This case demonstrates disparity between structural aberrations and final visual and neurological function and reinforces the association between MGS and intracranial vascular disruption. Full ancillary ophthalmic and neuroimaging studies should be performed in all patients with MGS with interval reassessments, even when the patient is asymptomatic and functionally intact.

Morning glory disc anomaly in childhood - a population-based study

PURPOSE

To report prevalence, ocular characteristics and coexisting neurological, behavioural, somatic and neuroradiological abnormalities in children and adolescents with morning glory disc anomaly (MGDA).

METHODS

In a cross-sectional population-based study, 12 patients with MGDA, aged 2-20 years, were identified. All 12 agreed to ophthalmological assessments including visual functions, refraction, fundus photography, optical coherence tomography (OCT) and ocular motor score (OMS). Neurological examinations and behavioural/developmental screening were carried out. Data from previous or new neuroradiological investigations were collected.

RESULTS

The prevalence of MGDA was 2.6/100 000. MGDA was unilateral in 11/12 patients with a best-corrected visual acuity (BCVA) in the MGDA eye ranging from hand motion to 0.65 (median 0.06). Severe microphthalmus prevented unilaterality to be determined in one adolescent. All patients had a binocular BCVA of ≥0.5. OMS showed abnormalities in pupil response, vestibulo-ocular reflex, stereo visual acuity, strabismus and convergence. OCT revealed peripapillary or macular oedema in 5/8 patients and foveal aplasia in 3/8 patients. Three patients had extensive capillary hemangiomas, of which one had PHACES syndrome and one had additional cerebrovascular anomalies and corpus callosum agenesis. Neuroradiology showed craniovascular anomalies in two patients. Neurology was mostly normal. Behavioural/developmental screening showed attention deficit hyperactivity disorder in one patient.

CONCLUSIONS

The prevalence data, previously not reported, of morning glory disc anomaly was 2.6/100 000. Coexisting retinal peripapillary or macular oedema was common, as were cerebral abnormalities and/or cutaneous vascular malformations. The associated findings may not be discovered through routine ophthalmological examination why OCT and neuroimaging are called for.

Congenital anomalies of the optic nerve

Congenital optic nerve head anomalies are a group of structural malformations of the optic nerve head and surrounding tissues, which may cause congenital visual impairment and blindness. Each entity in this group of optic nerve anomalies has individually become more prevalent as our ability to differentiate between them has improved due to better characterization of cases. Access to better medical technology (e.g., neuroimaging and genetic analysis advances in recent years) has helped to expand our knowledge of these abnormalities. However, visual impairment may not be the only problem in these patients, some of these entities will be related to ophthalmologic, neurologic and systemic features that will help the physician to identify and predict possible outcomes in these patients, which sometimes may be life-threatening. Herein we present helpful hints, associations and management (when plausible) for them.

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.

Clinical characteristics and treatment of 22 eyes of morning glory syndrome associated with persistent hyperplastic primary vitreous

PURPOSE

To describe the clinical manifestations and treatment outcomes in a retrospective case series of morning glory syndrome (MGS) associated with persistent hyperplastic primary vitreous (PHPV).

METHODS

The medical records of 85 eyes/74 patients referred for ophthalmology consultation diagnosed as MGS in our clinic were reviewed retrospectively. All patients underwent thorough ophthalmological examinations. 22 eyes of 19 patients diagnosed as having MGS associated with PHPV were included, accounting for 25.88% of all the MGS eyes. Clinical manifestations and management of these patients were documented.

RESULTS

15 patients (78.95%) were younger than 1 year old at the first diagnosis. Six eyes were associated with microphthalmia. 19 of 22 eyes (86.36%) had complications, including cataract (10 eyes), secondary glaucoma (8 eyes), corneal leucoma or oedema (8 eyes), retinal detachment (8 eyes), strabismus (3 eyes) and nystagmus (2 eyes). Treatment methods varied depending on the severity of the complications. Nine eyes with secondary glaucoma or cataract got lensectomy; three eyes underwent combined vitrectomy and lensectomy. Eight patients underwent cranial MRI/MR angiography or CT examination. Widened cerebral fissures of bilateral temporal lobes, abnormal dilated branch of middle cerebral artery in the left hemisphere and abnormal signal in the grey matter of frontal and occipital lobes were revealed respectively in three patients.

CONCLUSIONS

Our study revealed the coexistence of PHPV in a significant percentage of patients with MGS, suggesting a potential common genetic link. Compared with MGS and PHPV alone, the combination of the two conditions manifested with higher incidence and more severe complications in younger patients. Close follow-up was recommended. Lensectomy and vitrectomy were beneficial in the management of the complications.

A case of amblyopia with contralateral optic nerve hypoplasia

We describe an unusual case of unilateral optic nerve hypoplasia (ONH) in a patient with contralateral anisometropic/strabismic amblyopia. A seven-year-old boy presented with visual acuities of 6/12 R and 6/18 L and eccentric fixation in the left eye. Cycloplegic retinoscopy was R +1.50/-0.50 × 180 and L +5.25 DS. Funduscopy revealed optic nerve hypoplasia of the right eye. The patient fixated with his better-seeing right eye, despite the optic nerve hypoplasia. His reduced vision may be attributed to optic nerve hypoplasia in the right eye and amblyopia in the left. Although optic nerve hypoplasia can occur with ipsilateral amblyopia, we believe this is the first reported case of unilateral optic nerve hypoplasia in the fellow eye of an amblyopic patient.

Macular thinning associated with unilateral optic nerve hypoplasia

The authors present the case of an 8-year-old boy with a long-term diagnosis of unilateral optic nerve hypoplasia (ONH) of unknown cause in the right eye. Spectral-domain optical coherence tomography (SD-OCT) of the central macula was consistent with hypoplasia greatest in the inner retinal layers, but also involving the outer retinal layers when compared with the unaffected contralateral eye. Although ONH is commonly associated with hypoplasia of the nerve fiber and ganglion cell layers, it can also be associated with hypoplasia of other layers in the inner and outer retina, including the outer nuclear and photoreceptor inner/outer segment layers, as evidenced by SD-OCT.

Superior segmental optic nerve hypoplasia: The topless disc syndrome

BACKGROUND

Optic nerve hypoplasia is a well-known congenital maldevelopment presenting with an abnormally small optic nerve head occupying the central aspect of a normally sized chorioscleral canal. Characteristically, the optic nerve head is surrounded by scleral anlage with a "double ring sign." Less commonly appreciated, however, is the fact that optic nerve hypoplasia may be sectorial rather than total and involving only the superior aspect of the optic disc with corresponding inferior visual field loss.

CASE REPORT

A 51-year-old woman presented with a previous diagnosis of idiopathic optic atrophy superiorly in the left eye. Detailed observation revealed that the disc was not atrophic superiorly but actually hypoplastic, and the patient received a conclusive diagnosis of superior segmental optic nerve hypoplasia.

CONCLUSIONS

It must be appreciated that optic nerve hypoplasia can also affect solely the superior aspect of the disc with subsequent functional deficits. It is important to differentiate this syndrome from true optic atrophy to ensure proper management.

The clinical characteristics and imaging findings of morning glory syndrome

To investigate the features of CT, ultrasonography and fundus fluorescein angiography (FFA) of morning glory syndrome, the data on CT, A/B-scan ultrasonography and fundus fluorescein angiography (FFA) were retrospectively analyzed in 8 cases of morning glory syndrome (MGS). Among those cases, 6 were examined with CT, 4 with FFA and 8 with A/B-scan ultrasonography. Results showed that the characteristics of CT, A/B-scan ultrasonography and FFA in MGS included: (1) The attachment spot of optic nerve became thin and vitreous body protruded to the posterior wall of eyeball with a spherical shape on CT image; (2) in the early period of FFA, hypofluorescence appeared on the optic, the abnormal arteriae and veins around the optic papilla were displayed clearly and in the late period, optic disc was stained with fluorescein; (3) on B-scan ultrasonogram, the vitreous cavity extended to the posterior pole and optic papilla, and projected to the basal part of muscle cones and thus the posterior part of vitreous cavity looked like an upside-down bottleneck. Sometimes the echogenic band of retinal detachment could also be seen. On A-scan ultrasonogram, both vitreous cavity and bottleneck showed no ultrasonic echoes and presented a base line without any evident wave crest. It is concluded that CT, A /B-scan ultrasonography and FFA could show the imageological features of MGS from different aspects, which helps clinicians to differentiate it from other diseases such as optic disc coloboma. CT and A /B-scan ultrasonography, in particular, are considered to be reliable imageological methods for the accurate diagnosis of MGS and are superior to the traditional techniques.

Update on the morning glory disc anomaly

The morning glory disc anomaly has distinctive clinical characteristics and is important to diagnose correctly so that associated central nervous system and vascular abnormalities are promptly identified and treated. This review covers the ophthalmic findings, clinical features, and histopathologic findings in patients with this rare developmental abnormality. The most common systemic associations are described and reviewed.

[Rehabilitation on functional amblyopia in Morning Glory Syndrome]

INTRODUCTION

Morning Glory syndrome, characterized by an enlarged dysplasic optic disc with glial tissue, is one of the congenital anomalies of the optic nerve. This syndrome is rare, prevalent in the girls, and generally unilateral. It can be revealed with nystagmus, strabismus, or amblyopia.

OBSERVATION

We report the clinical observation of a 2.5-year-old girl, referred for the diagnosis of Morning Glory syndrome in the left eye with severe amblyopia (1/10 Rossano 1/20) and esotropia. This syndrome has associated central nervous system anomalies with a basal encephalocele. Treated with functional amblyopia therapy, visual acuity was 7/10 Rossano 1/2 after 1 year.

DISCUSSION

Rehabilitation on functional amblyopia in organic optic nerve anomalies is essential. A child with a Morning Glory syndrome, detected during the period of sensory maturation, must be treated with occlusion therapy, followed by maintenance treatment. This part of the treatment can prevent deep amblyopia. Moreover, regular ophthalmologic follow-up to detect complications of retinal detachment and multidisciplinary follow-up to detect a cytogenetic disease, CHARGE syndrome, or association with endocrine and central nervous system anomalies are necessary.

CONCLUSION

The author recommends occlusion therapy for children with Morning Glory syndrome or other organic asymmetric optic nerve anomalies, during the period of amblyopia reversibility. Most patients' vision improves after treatment. This case is an illustration.

Developmental abnormalities of the optic nerve and chiasm

Developmental anomalies of the optic nerve are an important and growing cause of lifelong visual handicap and they are often associated with systemic abnormalities. This review focuses on the ocular and systemic aspects of developmental anomalies arising from defects of fetal fissure closure and retinal ganglion cell development, and covers some other optic-disc anomalies that have systemic significance.