Detection and characterisation of visual field defects using Saccadic Vector Optokinetic Perimetry in children with brain tumours.

PURPOSE: To determine the ability of Saccadic Vector Optokinetic Perimetry (SVOP) to detect and characterise visual field defects in children with brain tumours using eye-tracking technology, as current techniques for assessment of visual fields in young children can be subjective and lack useful detail. METHODS: Case-series study of children receiving treatment and follow-up for brain tumours at the Royal Hospital for Sick Children in Edinburgh from April 2008 to August 2013. Patients underwent SVOP testing and the results were compared with clinically expected visual field patterns determined by a consensus panel after review of clinical findings, neuroimaging, and where possible other forms of visual field assessment. RESULTS: Sixteen patients participated in this study (mean age of 7.2 years; range 2.9-15 years; 7 male, 9 female). Twelve children (75%) successfully performed SVOP testing. SVOP had a sensitivity of 100% and a specificity of 50% (positive predictive value of 80% and negative predictive value of 100%). In the true positive and true negative SVOP results, the characteristics of the SVOP plots showed agreement with the expected visual field. Six patients were able to perform both SVOP and Goldmann perimetry, these demonstrated similar visual fields in every case. CONCLUSION: SVOP is a highly sensitive test that may prove to be extremely useful for assessing the visual field in young children with brain tumours, as it is able to characterise the central 30° of visual field in greater detail than previously possible with older techniques.

Raised intracranial pressure and retinal haemorrhages in childhood encephalopathies.

AIM: To explore the relationship between raised intracranial pressure (RICP) and retinal haemorrhages in traumatic and non-traumatic childhood encephalopathies. METHOD: A prospective study of 112 children (35 females and 77 males, age range 0.01mo-17y 8.3mo; mean 5y 8.6mo, median 4y 5.6mo) included 57 accidental traumatic brain injuries (ATBIs), 21 inflicted traumatic brain injuries (ITBIs), and 34 non-traumatic encephalopathy cases. Measurements included intracranial pressure (ICP), cerebral perfusion pressure, pressure-time index of ICP, and number, zone, and layer of retinal haemorrhages on retinal imaging. RESULTS: Group I had measured elevated ICP (n=42), Group II had clinical and/or radiological signs of RICP (n=21), and Group III had normal ICP (n=49). In the combined Groups I and II, 38% had retinal haemorrhages. Multiple logistic regression confirmed that the presence of retinal haemorrhages was significantly related to the presence of RICP independent of age and aetiology; however, the occurrence and overall numbers were not significantly related to the specific ICP level. The numbers of intraretinal (nerve-fibre layer and dot blot) retinal haemorrhages were significantly greater in those with RICP. The ITBI population was significantly different from the other combined aetiological categories. INTERPRETATION: The study results indicate a complex RICP/retinal haemorrhage relationship. There was no evidence of existing retinal haemorrhages being exacerbated or new retinal haemorrhages developing during periods of confirmed RICP.

Prediction of inflicted brain injury in infants and children using retinal imaging.

BACKGROUND: Retinal hemorrhages (RHs) occur in inflicted traumatic brain injury (ITBI), accidental traumatic brain injury (ATBI), and some medical conditions, although the reported number, distribution, type, and frequency vary greatly between these different etiologies. We hypothesize that these RH characteristics reliably help to distinguish ITBI from ATBI and nontraumatic etiologies. METHODS: A 6-year prospective observational study using wide-field retinal imaging (RetCam) was conducted within 24 hours of admission to PICU, on serially recruited children with traumatic and nontraumatic encephalopathies. "Definite" and "probable" ITBI cases were confirmed by multiagency child protection case conferences. Image analysis used digital color and grayscale images for retinal "zoning" and "layering" of hemorrhages. RESULTS: Significant differences were found between the mean numbers of hemorrhages in ATBI/ITBI, and ITBI/nontraumatic etiologies for the 3 retinal zones (range, P = .003-.009) and for the dot-blot hemorrhages (range P = .001-.002). The mean numbers of RHs per ITBI patient in the peripapillary, macula, and peripheral zones were 14, 28, and 31 respectively. RHs in ATBI were near the optic disc and more superficial than in ITBI, where hemorrhages involved deeper layers (range, P = .003-.039) and were more peripheral (P = .03). The positive predictive value for ITBI in children <3 years with >25 dot-blot (intraretinal) hemorrhages was 93%. CONCLUSIONS: This prospective study, which included all potential causes of RHs, with objective retinal methodology, has confirmed that a young age and a high dot-blot count are strong predictors of ITBI. This high predictive value may support medicolegal deliberations.

Nystagmus and reduced visual acuity secondary to drug exposure in utero: long-term follow-up.

PURPOSE: To investigate nystagmus and other visual system abnormalities among children exposed to opiates and benzodiazepines in utero. METHODS: Retrospective case series comprising clinical examination and case note review of 25 children with nystagmus and reduced vision who were exposed to controlled drugs during pregnancy. RESULTS: Twenty-four children were exposed to opiates, of whom 13 were also exposed to diazepam. One child was exposed to diazepam alone. All children had horizontal nystagmus, which was either fine pendular or jerk type. The nystagmus had a latent element in 4 children and 8 adopted a compensatory head posture. Where the time of onset of nystagmus was known, it was always prior to 6 months of age. At least 9 children (36%) had delayed visual maturation. The mean initial logarithm of the minimum angle of resolution binocular best-corrected visual acuity (BCVA) was 0.54 at an average of 22 months of age. Thirteen children were followed up for 6 months or longer and their BCVA improved to 0.4 at an average age of 48 months. The nystagmus was clinically improved in only 5 patients. Electroretinogram testing was normal in the 4 children tested. The only ocular structural abnormality was binocular optic nerve hypoplasia in 2 children. CONCLUSION: Exposure to opiates and benzodiazepines in utero may be associated with permanent nystagmus and reduced visual acuity. This is most likely the result of insult(s) to the central nervous system rather than the eyes.

An inter-observer and intra-observer study of a classification of RetCam images of retinal haemorrhages in children.

BACKGROUND: There is currently no universally accepted classification of childhood retinal haemorrhages. AIM: To measure the inter- and intra-observer agreement of clinical classifications of retinal haemorrhages in children. METHODS: Four examiners (two consultant ophthalmologists and two other clinicians) were shown 142 retinal haemorrhages on 31 RetCam photographs. The retinal haemorrhages were from children with accidental or abusive head injury, or other encephalopathies, and included retinal haemorrhages of different ages. Specified haemorrhages were initially classified by each examiner according to their clinical understanding. Altogether, 26 haemorrhages were re-presented to test intra-observer consistency. Examiners then agreed a common description for each haemorrhage type and five categories were described (vitreous, pre-retinal, nerve fibre layer, intra-retinal/sub-retinal or indeterminate) and the study repeated. RESULTS: There was 'fair agreement' initially (Fleiss' unweighted κ=0.219) and, with the agreed classification, slight improvement (0.356). Intra-observer agreement marginally improved on re-test. The two consultant ophthalmologists showed 'fair' agreement on both occasions (paired κ statistic). The other rater pair improved from 'fair' to 'substantial' agreement with the new classification. CONCLUSIONS: The classification of retinal haemorrhage in children by appearance alone shows only fair agreement between examiners. Clinicians who are not consultant ophthalmologists appear to benefit from the new succinct classification.

An interrater reliability study of a new 'zonal' classification for reporting the location of retinal haemorrhages in childhood for clinical, legal and research purposes.

BACKGROUND/AIMS: To develop and assess a zonal classification of the retina to facilitate description of the location of retinal haemorrhages in children. METHODS: A novel zonal classification of the retina was devised based on the anatomical landmarks of the optic disc and vascular arcades, by reviewing a large number of wide field digital retinal images drawn from our database of children with accidental and non-accidental head injury and other encepthalopathies. Four expert examiners then independently 'located' 142 retinal haemorrhages by zone, from 31 high quality photographs. RESULTS: Cohen's unweighted kappa scores for all possible pairs of the four raters (ie, six pairs) ranged from 0.86 to 0.92, that is 'almost perfect' agreement. Fleiss' kappa for agreement between multiple raters (four) and for multiple categories (three) was 0.8841, that is 'almost perfect' agreement. Cohen's unweighted kappa statistic for intrarater reliability gave an overall concordance that ranged from 'substantial' to 'perfect' agreement. CONCLUSION: This new retinal zone classification and the use of photographs and templates is a very reliable tool for reporting the location of retinal haemorrhages from multiple aetiologies in children, and may be useful for research and medico-legal reports.

Nystagmus secondary to drug exposure in utero.

AIM: To report the occurrence of nystagmus in children exposed to opiates and/or benzodiazepines during pregnancy, and to describe the associated ocular and systemic findings. METHODS: Clinical examination and casenote review of 14 children with nystagmus whose mothers had misused opiates and/or benzodiazepines during pregnancy. RESULTS: Twelve children were exposed to opiates during pregnancy, of whom nine had also been exposed to benzodiazepines. Two children were exposed to benzodiazepines alone. In the primary position, the nystagmus was a fine horizontal pendular type in 10 (71.4%) children and was a fine horizontal jerk nystagmus in the other 4 (28.6%) children. The onset of the nystagmus probably occurred in the first 6 months of life in all cases. The mean binocular best-corrected logarithm of the minimum angle of resolution visual acuity was 0.59 (20/80). Electroretinogram and visual evoked potential examinations were found to be normal in the three children tested. Nine (64.3%) children had developmental delay and at least 7 (50%) had delayed visual maturation. Six children had microcephaly and two had bilateral optic nerve hypoplasia. None of the children had a specific neurological diagnosis or seizure disorder. CONCLUSION: This study strongly supports a teratogenic association between exposure to controlled drugs in utero and infantile nystagmus. Furthermore, the nystagmus and associated clinical features seem to be particularly associated with combined use of opiates and benzodiazepines. Exposure to opiates and/or benzodiazepines during pregnancy should be considered in the differential diagnosis of infantile nystagmus.