Orbital sonography in children

Imaging the pediatric retina: An overview

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

The Development of Ocular Biometric Parameters in Premature Infants without Retinopathy of Prematurity

PURPOSE

The aim of this study was to investigate the developmental tendencies and distribution of ocular biometric parameters in premature infants without retinopathy of prematurity (ROP). Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and vitreous length (VL) were measured, and their relationships with birth weight (BW) and postmenstrual age (PMA) were analyzed during their earliest weeks of life.

METHODS

This cross-sectional cohort study included 633 premature infants. They were divided into nine groups according to their PMA: 32 weeks, 33 weeks, 34 weeks, and onward to 40 weeks. All participants underwent portable slit-lamp examination, RetCam3 and A-scan ultrasound biometry. The following ocular biometric parameters were recorded: AL, ACD, LT and VL. The t-test, one-way analysis of variance, and the multiple regression analysis model were used to analyze the data.

RESULTS

The increases in AL, ACD, LT and VL were 0.14 mm, 0.028 mm, 0.0025 mm and 0.11 mm per week, respectively. AL, ACD, LT and VL were positively correlated with BW (β = 0.000337, 4.234E-5, 2.697E-5, 0.000278, respectively) and PMA (β = 0.142, 0.026, 0.011, 0.103, respectively).

CONCLUSIONS

With maturation, AL and VL increased and ACD deepened, but there was no significant change in LT. The ocular growth parameters were positively correlated with BW and PMA however the correlations were not strong.

Evaluation of Bedside Sonographic Measurement of Optic Nerve Sheath Diameter for Assessment of Raised Intracranial Pressure in Adult Head Trauma Patients

Aim:

The aim was to evaluate the use of bedside sonographic measurement of the optic nerve sheath diameter (ONSD) in the assessment of elevated intracranial pressure in patients with head injury coming to the emergency department (ED).

Methods:

A prospective study of ED patients presenting with a history of acute head injury, an ocular ultrasound was performed for ONSD measurement, followed by a computed tomography (CT) of the brain. Three measurements were taken for each eye, then, the mean binocular ONSD measurement for each patient was obtained to ensure accuracy. A mean bipolar ONSD >5 mm was considered abnormal.

Results:

A total of 175 patients were considered for the study. Of 175 patients, only 56 (32%) had intracranial pathology detected on CT brain with mean ONSD of 5.7 mm (standard deviation [SD]: 0.59). The mean ONSD for 119 (68%) patients, who had normal CT brain, was 4.5 mm (SD: 0.42). The mean ONSD measured for the right eye was 4.86 mm with SD 0.88, and the mean ONSD for the left eye was 4.90 mm with SD 0.85. When comparing ONSD measurement with CT findings of raised intracranial pressure, the ONSD sensitivity was 87.5% (95% confidence interval [CI]: 85%–96%) and specificity was 94.1% (95% CI: 85%–96%), with a positive predictive value of 87.5% and a negative predictive value of 94.1%. The area under the receiver operator characteristic curve obtained was 0.90 (95% CI: 0.85–0.96).

Conclusion:

The study has shown a bedside measurement of ONSD through sonography as an efficient tool to assess elevations in intracranial pressure in head injury patients.

Point-of-Care Ultrasound Diagnosis of Retinoblastoma in the Emergency Department

An 18-month-old girl presented to the emergency department with the chief complaint of squinting. The right eye demonstrated esotropia, heterochromia, and anisocoria. Ocular point-of-care ultrasound facilitated the rapid diagnosis of retinoblastoma, which was confirmed by computed tomography scan and orbital magnetic resonance imaging.

Doppler Ultrasonography of the Central Retinal Vessels in Children With Brain Death

OBJECTIVE

The purpose of this observational study is to explore if bedside Doppler ultrasonography of the central retinal vessels has the potential to become an ancillary study to support the timely diagnosis of brain death in children.

DESIGN

Seventeen-month prospective observational cohort.

SETTING

Forty-four bed pediatric medical and surgical ICU in an academic teaching hospital.

PATIENTS

All children 0-18 years old who were clinically evaluated for brain death at Children's National Health Systems were enrolled and followed until discharge or death.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients had at least one ophthalmic ultrasound within 30 minutes of each brain death examination. The central retinal artery peak systolic blood flow velocity, resistive index, pulsatility index, and Doppler waveforms were evaluated in each patient. Thirty-five ophthalmic ultrasounds were obtained on 13 patients, 3 months to 15 years old, who each had two clinical examinations consistent with brain death. The average systolic blood pressure during the ultrasound examinations was 102 mm Hg (± 28), diastolic blood pressure 65 mm Hg (± 24), mean arterial pressure 79 mm Hg (± 23), heart rate 133 beats/min (± 27), temperature 36°C (± 0.96), arterial CO2 35 mm Hg (± 9), and end-tidal CO2 23 mm Hg (± 6). For all examinations, the average peak systolic velocity of the central retinal artery was significantly decreased at 4.66 cm/s (± 3.2). Twelve of 13 patients had both resistive indexes greater than or equal to 1, average pulsatility indexes of 3.6 (± 3.5) with transcranial Doppler waveforms consistent with brain death. Waveform analysis of the 35 ultrasound examinations revealed 11% with tall systolic peaks without diastolic flow, 17% with oscillatory flow, 29% showed short systolic spikes, and 23% had no Doppler movement detected. A rippling "tardus-parvus" waveform was present in 20% of examinations.

CONCLUSION

This study supports that the combination of qualitative waveform analysis and quantitative blood flow variables of the central retinal vessels may have the potential to be developed as an ancillary study for supporting the diagnosis of brain death in children.

Usefulness of colour Doppler flow imaging in the management of lacrimal gland lesions

OBJECTIVE

To assess the role of colour Doppler flow imaging (CDFI) in the diagnosis and management of lacrimal fossa lesions.

METHODS

Institutional ethical committee approval was obtained. Fifty-one patients with 62 lacrimal fossa lesions were retrospectively included from 2003-2015. All patients underwent conventional ultrasonography and CDFI, with a qualitative and quantitative analysis of the vascularization. All patients had lacrimal gland surgery. Definitive diagnosis was based on pathological examination.

RESULTS

The study included 47 non-epithelial lesions (NEL) and 15 epithelial lesions (EL), with 24 (39 %) malignant lesions and 38 (61 %) benign lesions. NEL were significantly more likely to present with septa (p < 0.001), hypoechogenicity (p < 0.001), high vascular intensity (p < 0.001), both central and peripheral vascularization (p < 0.001), tree-shape vascularization (p < 0.05) and a low resistance index (RI) (p < 0.0001). EL were significantly more likely to present with the presence of cysts (p < 0.001), and a higher RI. Receiver operating characteristic curves identified a RI value of 0.72 as the best cut-off to differentiate NEL from EL, with a sensitivity and specificity of 100 %.

CONCLUSION

CDFI is a valuable tool in the differential diagnosis of lacrimal fossa lesions. Resistance index measurement enables substantial distinction between EL and NEL, thus providing crucial data for surgical management.

KEY POINTS

• CDFI is a valuable tool in lacrimal fossa lesions. • Resistance Index measurement enables substantial distinction between epithelial and non-epithelial lesions. • Management of patients becomes more appropriate.

US and MRI of pediatric ocular masses with histopathological correlation

We review our experience with unusual ocular pathologies, some mimicking retinoblastoma, that were referred to our institution during the past two decades. After presenting the imaging anatomy of the normal eye, we discuss pertinent clinical and pathological features, and illustrate the US and MRI appearance of retinoblastoma, medulloepithelioma, uveal melanoma, persistent fetal vasculature, Coats disease, corneal dermoid, retinal dysplasia and toxocara granuloma. Features useful in discriminating among these entities are emphasized.

Refractive status and ocular axial length in preterm infants without retinopathy of prematurity with regard to birth weight and gestational age

PURPOSE

To obtain ultrasonographic measurements of ocular axial length (AL) in preterm infants without retinopathy of prematurity (ROP) but with different refractive power in regard to birth weight (BW) and gestational age (GA).

METHODS

Refraction was measured after cycloplegia (at 6 months of life) in 350 eyes of 180 preterm (non-astigmatic) infants without ROP. Subjects were grouped according to the refractive error: A [above -6.0 dioptres (D)]; B (-3.1 to -6.0 D); C (0 to -3.0 D); D (0.1 to +3.0 D); E (+3.1 to +6.0 D); F (above +6.0 D). The AL measurement was performed by ocular A-scan ultrasound biometry (10 MHz probe).

RESULTS

The longest AL was found in group B (20.62 mm) compared to group D and E (19.35, 19.28 mm; P< or =0.01) and group F and A (19.63, 19.39 mm; P< or =0.05). Only regressive correction for BW was statistically significant. Correlations between AL and BW (Rs=0.23) or GA (Rs=0.17) were found only in group E.

CONCLUSIONS

AL of myopic eyes was significantly longer. In general, hyperopia was positively correlated with BW, whereas correlation between myopia and BW or GA was not found.

Bedside sonographic measurement of optic nerve sheath diameter as a predictor of increased intracranial pressure in children

STUDY OBJECTIVE

We investigate the test performance of emergency physician-performed sonographic measurement of optic nerve sheath diameter for diagnosis of increased intracranial pressure.

METHODS

Children between the ages of 0 and 18 years with suspected increased intracranial pressure were prospectively recruited from the emergency department and ICU of an urban, tertiary-level, freestanding pediatric facility. Pediatric emergency physicians with goal-directed training in ophthalmic sonography measured optic nerve sheath diameter. Images were recorded and subsequently reviewed by a pediatric ophthalmologist and an ophthalmic sonographer, both of whom were blind to the patient's clinical condition. Measurements obtained by the ophthalmic sonographer were considered the criterion standard. An optic nerve sheath diameter greater than 4.0 mm in subjects younger than 1 year and greater than 4.5 mm in older children was considered abnormal. The diagnosis of increased intracranial pressure was based on results of cranial imaging or direct measurement of intracranial pressure.

RESULTS

Sixty-four patients were recruited, of whom 24 (37%) had a confirmed diagnosis of increased intracranial pressure. The sensitivity of optic nerve sheath diameter as a screening test for increased intracranial pressure was 83% (95% confidence interval [CI] 0.60 to 0.94); specificity was 38% (95% CI 0.23 to 0.54); positive likelihood ratio was 1.32 (95% CI 0.97 to 1.79) and negative likelihood ratio was 0.46 (95% CI 0.18 to 1.23). There was fair to good interobserver agreement between the pediatric emergency physician and ophthalmic sonographer (kappa 0.52) and pediatric ophthalmologist (kappa 0.64).

CONCLUSION

The sensitivity and specificity of bedside sonographic measurement of optic nerve sheath diameter is inadequate to aid medical decisionmaking in children with suspected increased intracranial pressure. Pediatric emergency physicians with focused training by a pediatric ophthalmologist familiar with ophthalmic sonography can measure optic nerve sheath diameter accurately.

Blood flow velocities are reduced in the optic nerve of children with elevated intracranial pressure

The authors previously used spectral Doppler imaging to determine optic nerve blood flow velocities in normal children. In the current study, we measured central retinal artery and central retinal vein blood flow velocities by spectral Doppler imaging in 38 healthy children and 18 children with elevated intracranial pressure between ages 4 and 17. We found central retinal artery systolic blood flow velocity was significantly reduced in children with elevated increased intracranial pressure; ANOVA P = .01 (normal children 8.9 cm/s [SD 1.1] versus children with elevated intracranial pressure 7.5 cm/s [SD 1.3]). Central retinal vein maximal blood flow velocity was also significantly reduced in children with elevated intracranial pressure; ANOVA P < .02 (normal children 4.2 cm/s [SD 0.9] versus children with elevated intracranial pressure 3.6 cm/s [SD 0.7]). Spectral Doppler imaging is a noninvasive test well tolerated in children that identifies blood flow velocity changes in elevated intracranial pressure.

MRI of the fetal eyes: morphologic and biometric assessment for abnormal development with ultrasonographic and clinicopathologic correlation

BACKGROUND

Currently ocular biometric measurements are defined by US and are measured from the orbital walls. These bony landmarks cannot be seen by MRI, and therefore these measurements cannot be directly applied.

OBJECTIVE

To define measurements of normal growth of the fetal eyes using MRI.

MATERIALS AND METHODS

Transorbital views were analyzed in 198 fetal MR examinations. The ocular diameter (OD) and interocular and binocular distances (IOD and BOD) were measured and were plotted against gestational age. Fetuses with abnormalities affecting the eyes were evaluated separately.

RESULTS

Of 198 scans, 146 had suitable images, 35 of which were abnormal. Normal growth of BOD, IOD and OD were determined, and compared with the respective already established US data.

CONCLUSION

Normal growth charts were derived from a cohort of 111 normal fetuses. Because the margins of the vitreous are inside the bony orbit, at the same gestational age measurements of the BOD and OD are always less than the corresponding measurements by US, and those of the IOD are always more. Normal growth charts for MRI can now be used to support suspected diagnoses of orbital and ocular pathologies and the syndromes that give rise to them, and many examples are demonstrated.

Sonography of the eye

OBJECTIVE

The purpose of this study is to show how sonography can reveal pathology of the eye and to highlight its usefulness as a simple and cost-effective tool in investigating eye symptoms.

CONCLUSION

The cystic nature of the eye, its superficial location, and high-frequency transducers make it possible to clearly show normal anatomy and pathology such as tumors, retinal detachment, vitreous hemorrhage, foreign bodies, and vascular malformations. Sonography is useful as a treatment follow-up technique because it has no adverse effects. Sonography is well tolerated by patients and relatively easy to perform for those familiar with real-time sonography.

Three dimensional ultrasound of retinoblastoma: initial experience

AIM

To use 3D ultrasonography (3DUS) for the diagnosis of retinoblastoma.

METHODS

Five eyes of three children with retinoblastoma were evaluated using a commercially available computerised 3DUS system. Interactive sectioning of the stored and reconstructed 3D volumes were performed. 3DUS and histopathological findings were correlated after enucleation.

RESULTS

3DUS examination revealed characteristics consistent with retinoblastoma: endophytic mass, retinal detachment, intratumoural calcifications, and secondary orbital shadowing. Unlike 2D imaging, 3DUS allowed for analysis of the acquired and stored volumes. Rotation and sectioning of this volume allowed the discovery of new oblique and coronal views. For example, calcium related orbital shadows were seen as 3D volumes and (coronal) cross sections of the optic nerve were evaluated for evidence of intraneural invasion by retinoblastoma.

CONCLUSION

This is the first reported series of patients examined with 3DUS imaging for retinoblastoma. This technique allowed for new oblique and coronal views of the tumour and optic nerve. The ability to retrospectively analyse the (scanned and stored) ocular volume facilitated patient care, teaching, tumour-volume analysis, and telemedicine.

Axial growth of the fetal eye and evaluation of the hyaloid artery: in utero ultrasonographic study

The aims of this prospective, cross-sectional study were to report axial ocular growth during human gestation, to determine the presence of the hyaloid artery (HA) and its blood flow, and to provide a timetable for HA regression. The study group comprised 231 low-risk singleton pregnancies between 14 and 38 weeks' gestation. Ocular axial length (OAL), anterior chamber depth (ACD) and posterior chamber depth (PCD) were measured using high-resolution ultrasound. The growth of these eye segments in correlation with gestational age (GA) was established. The presence of the HA and its regression were determined. By using power Doppler, ultrasound blood flow within the HA was estimated. HA regression is a gradual process that is not evident before 18 weeks' gestation. In all fetuses beyond 29 weeks' gestation, no HA could be detected (P<0.001). Blood flow within the HA was documented only until the 16th week of gestation. The correlation coefficients, r=0.924, 0.784 and 0.929, for OAL, ACD and PCD, respectively, were found to be highly statistically significant (P<0.0001). The present data offer normative measurements of the fetal axial eye lengths, timetable for HA regression and flow cessation.