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Biomedical subjects

G G W Adams

Publications and source records attributed to G G W Adams.

15 recordsLinked to original sources
PubMed2006

Batten disease: features to facilitate early diagnosis.

AIMS: To ascertain the clinical and electrophysiological features in patients with juvenile neuronal ceroid lipofuscinosis (jNCL/Batten disease) and to identify those features that facilitate early diagnosis. METHODS: Nine patients with jNCL were identified retrospectively and their case notes reviewed. All had undergone an extensive clinical examination, including electrophysiology. Blood and molecular genetic testing confirmed the diagnosis. RESULTS: Age at onset ranged from 4-8 years. At presentation, two of nine patients had normal fundi; only two of nine patients had a bull's eye maculopathy. The electroretinogram (ERG) findings in this series included undetectable rod specific ERGs, an electronegative maximal response, reduced and delayed cone flicker ERGs, reduction in the b:a ratio in the photopic single flash ERG, and an undetectable pattern ERG. Vacuolated lymphocytes on peripheral blood film testing were present in eight of nine patients. Five of eight patients were homozygous for the 1.02 kb deletion on the CLN3 gene on molecular genetic testing; two of eight patients were heterozygous for that deletion. CONCLUSION: jNCL should be considered in children of 10 years and under presenting with visual loss and fundal changes ranging from normal through to pigmentary/atrophic changes or a bull's eye maculopathy. Electrophysiology may suggest jNCL. Although currently untreatable, early diagnosis is important to institute appropriate counselling and support.

Child↗
PubMed2005

Retinal dysfunction and refractive errors: an electrophysiological study of children.

AIMS: To evaluate the relation between refractive error and electrophysiological retinal abnormalities in children referred for investigation of reduced vision. METHODS: The study group comprised 123 consecutive patients referred over a 14 month period from the paediatric service of Moorfields Eye Hospital for electrophysiological investigation of reduced vision. Subjects were divided into five refractive categories according to their spectacle correction: high myopia (< or = -6D), low myopia (>-6D and < or = -0.75D), emmetropia (>-0.75 and <1.5D), low hyperopia (> or = 1.5 and <6D), and high hyperopia (> or = 6D). Patients with a specific diagnosis at the time of electrophysiological testing were excluded. Only the first member of any one family was included if more than one sibling had been tested. All tests were performed to incorporate ISCEV standards, using gold foil corneal electrodes where possible. In younger patients skin electrodes and an abbreviated protocol were employed. RESULTS: The mean age of patients was 7.1 years with an overall incidence of abnormal electrophysiological findings of 29.3%. The incidence of abnormality was higher in high ametropes (13/25, 52%) compared to the other groups (23/98, 23.5%). This difference was statistically significant (chi2 test, p = 0.005). There was also a significant association between high astigmatism (>1.5D) and ERG abnormalities (18/35 with high astigmatism v 20/88 without, chi2 test, p = 0.002). There was no significant variation in frequency of abnormalities between low myopes, emmetropes, and low hyperopes. The rate of abnormalities was very similar in both high myopes (8/15) and high hyperopes (5/10). CONCLUSIONS: High ametropia and astigmatism in children being investigated for poor vision are associated with a higher rate of retinal electrophysiological abnormalities. An increased rate of refractive errors in the presence of retinal pathology is consistent with the hypothesis that the retina is involved in the process of emmetropisation. Electrophysiological testing should be considered in cases of high ametropia in childhood to rule out associated retinal pathology.

Adolescent↗
PubMed2005

Postmortem monocular indirect ophthalmoscopy.

Postmortem monocular indirect ophthalmoscopy permits examination of the posterior fundus and peripheral retina even if there is less than perfect anterior segment media such as postmortem corneal clouding. Light directed through the decedent's pupil from a bright focal light source illuminates the fundus and reflected light from the retina is then projected out of the eye. An aspheric condensing lens positioned in front of the eye focuses the retinal image at the focal plane of the lens. The real inverted, laterally reversed image comprises a wide field of view permitting evaluation of the decedent's fundus for retinal hemorrhages and other lesions.

Forensic Pathology↗
PubMed2004

Pilot study of the systemic effects of three different screening methods used for retinopathy of prematurity.

PURPOSE: This pilot study compared the physiological and behavioural changes in premature infants undergoing three different methods of screening for retinopathy of prematurity (ROP). STUDY DESIGN: Prospective randomized cross-over pilot study. SUBJECTS AND METHODS: Fifteen premature infants requiring screening for ROP were recruited, and physiological and behavioural responses produced by three different methods of screening were compared. The screening methods employed a RetCam 120 and an indirect ophthalmoscope with and without an eyelid speculum. Physiological indices (change in pulse, mean blood pressure and oxygen saturation) and facial responses to pain (brow bulge, eye squeeze, nasolabial fold, mouth opening and the presence of cry) were recorded at five points: before, during and immediately after screening and 10 and 30 min after examination. RESULTS: Screening with the RetCam 120 and the indirect ophthalmoscope with a speculum both caused a greater change in pulse and mean blood pressure and an increase in facial responses to pain during and immediately after screening as compared to the indirect ophthalmoscope without the speculum. RetCam 120 screening caused greater desaturation than the other methods. CONCLUSIONS: Although this was a small sample which limits absolute conclusions, the study showed that screening using a RetCam or a speculum and indirect ophthalmoscope caused more stress to the infant, as indicated by physiological and behavioural changes, than simply screening using an indirect ophthalmoscope without a speculum. These effects should be considered when deciding on the appropriate screening method for examining particularly sick infants.

Face↗
PubMed2004

Ocular coloboma and high myopia with Hirschsprung disease associated with a novel ZFHX1B missense mutation and trisomy 21.

Syndromic Hirschsprung disease has been associated with mutations in ZFHX1B, a Smad-interacting transcriptional repressor protein. Tissue in situ hybridization has demonstrated strong expression of ZFHX1B in the developing eye, suggesting that some mutations in this gene may cause visual loss. However, none of the reported mutations have been associated with an ocular phenotype. We describe a patient with Down syndrome and Hirschsprung disease with high myopia and ocular coloboma affecting the iris and retina. In addition to trisomy 21, a novel, de novo heterozygous A to G transition in exon 8 of the ZFHX1B gene was identified, which results in a R953G amino acid substitution. This abnormality was not seen in a screen of 200 chromosomes from ethnically matched, normal controls. The arginine residue at position 953 is an extremely conserved amino acid throughout evolution. This is the first report associating Hirschsprung disease and severe eye defects with a specific genetic mutation and is the first report of a mutation in ZFHX1B causing a developmental ocular anomaly.

Abnormalities, Multiple↗
PubMed2003

Dural haemorrhage in non-traumatic infant deaths: does it explain the bleeding in 'shaken baby syndrome'?

A histological review of dura mater taken from a post-mortem series of 50 paediatric cases aged up to 5 months revealed fresh bleeding in the dura in 36/50, the bleeding ranging from small perivascular haemorrhages to extensive haemorrhage which had ruptured onto the surface of the dura. Severe hypoxia had been documented clinically in 27 of the 36 cases (75%). In a similar review of three infants presenting with classical 'shaken baby syndrome', intradural haemorrhage was also found, in addition to subdural bleeding, and we believe that our findings may have relevance to the pathogenesis of some infantile subdural haemorrhage. Recent work has shown that, in a proportion of infants with fatal head injury, there is little traumatic brain damage and that the significant finding is craniocervical injury, which causes respiratory abnormalities, severe global hypoxia and brain swelling, with raised intracranial pressure. We propose that, in such infants, a combination of severe hypoxia, brain swelling and raised central venous pressure causes blood to leak from intracranial veins into the subdural space, and that the cause of the subdural bleeding in some cases of infant head injury is therefore not traumatic rupture of bridging veins, but a phenomenon of immaturity. Hypoxia with brain swelling would also account for retinal haemorrhages, and so provide a unified hypothesis for the clinical and neuropathological findings in cases of infant head injury, without impact or considerable force being necessary.

Diagnosis, Differential↗
PubMed2002

Contact lenses in the management of high anisometropic amblyopia.

UNLABELLED: Poster at College Congress, Birmingham 2001. Oral presentation at European Strabismus Association, Florence 2001. PURPOSE: Anisometropia of more than one dioptre during the sensitive visual period may cause amblyopia. Its management requires refractive correction, and occlusion. Compliance with treatment is critical if visual improvement is to obtained. High anisometropia, poor initial acuity and mixed strabismic/anisometropia amblyopia are predictive factors for a poor outcome. We evaluated contact lens use in the management of high anisometropic amblyopia. METHODS: Retrospective analysis of anisometropic amblyopia managed in a paediatric contact lens clinic (July 1996-July 2000), after standard amblyopia therapy of spectacles and occlusion therapy had been tried. Presenting age, acuity and refraction, duration of lens wear and occlusion, and final visual outcomes were noted. RESULTS: Seven children (four male, three female) presented at age 3.5-6 years (mean 4.5). Six had myopic anisometropia 6.0-18.4 dioptres (mean 10.4 dioptres) and one 6.75 dioptres hypermetropic anisometropia. The initial corrected acuities of the amblyopic eyes were 6/18 to 1/60. Five patients used contact lenses with a range from 5 months to 4 years. Final acuities were 6/12-1/60. Two myopes with 6 dioptres anisometropia improved three to four Snellen lines, one with 8.8 dioptres improved one line. Three with >10 dioptres anisometropia did not improve. The hypermetropic patient improved part of one Snellen line. CONCLUSIONS: High anisometropic amblyopia is challenging to treat. In our study contact lenses improved visual acuity in myopic anisometropia of up to 9 dioptres.

Amblyopia↗
PubMedDate not supplied

Violence is not necessary to produce subdural and retinal haemorrhage: a reply to Punt et al.

In this article we reply to the recent critique by Punt et al. in Pediatric Rehabilitation. Our hypothesis about the pathogenesis of intracranial bleeding in infants has three important implications. First, in the case of an infant with a swollen brain, subdural and retinal haemorrhage but no objective evidence of trauma, the findings by themselves are not certain evidence of abuse; second, violence is not necessary to produce subdural and retinal haemorrhage; and lastly, non-traumatic events producing apnoea with a catastrophic rise in intracranial pressure could produce a clinical picture identical to that seen in trauma.

Brain Hemorrhage, Traumatic↗