SUMMARY Prospective studies have suggested that about 108 children with congenital cytomegalovirus (CMV) infection and bilateral sensorineural hearing loss are born each year in England and Wales; this represents about 12% of all children with congenital sensorineural hearing loss. Over a nine year period 1644 children aged between 6 months and 4 years who were attending the Nuffield Hearing and Speech Centre were screened for CMV infection. The prevalence of CMV in the urine of children with sensorineural hearing loss but no immediate family history of deafness was nearly twice that (13%) found in other children with impaired hearing and those with normal hearing (7%). These findings indicate the importance of CMV as a cause of hearing loss.

Hand Eczema-Bettley M R Nr 155Seventeen per cent. of cases were thought to be occupational. In the diagnosis of industrial dermatitis the course of the illness, especially in relation to changes in work, is often of decisive importance.REFERENCES Calnan, C. D., and Wells, G. C. (1956). Brit. med. 7., 1, 12651, . Gross, P. (1959. Ann. Allergy, 17, 745. Heseltine, G. F. (1963). 7. psychosom. Res., 7, 241. Hjorth, N. (1963). Trans. St 7ohn's Hosp. derm. Soc. (Lond.), 49, 99. MacKenna, R. M. B. (1961). Practitioner, 186, 737. Sulzberger, M. B., and Baer, R. L. (1948 The exact nature of the risk of foetal damage following infection is hard to assess except in the case of rubella. This relationship was first noted by Gregg (1941) and later by Swan (1944), who drew attention to malformation of the eyes and hearing-organs after maternal rubella in the first trimester.The detailed prospective studies of Lundstr6m (1952, 1962) in Sweden and Manson et al. (1960) in England provided the necessary data for evaluation of this risk. Apart from a slightly higher incidence of stillbirths and infant deaths, the main effects noted were cataracts, deafness, and congenital heart disease, particularly patent ductus arteriosus, microcephaly, and coexistent mental retardation. These defects, occurring either singly or in combination, are referred to collectively as the rubella syndrome. In Lundstrdm's series 1,146 pregnant women exposed to rubella were studied. The incidence of the rubella syndrome was 11%, 11%, and 8% for each of the first three months respectively, with an overall incidence of 10% for the first trimester. The teratogenic effect of rubella on the human foetus is the reason for studying this otherwise mild infectious disease. The recent discovery, by several groups in North America, that the virus could be grown in cell culture opened up a new approach to the study of rubella and of the mechanism producing foetal damage. The first point studied was the serological status of children with the rubella syndrome. It was shown by Plotkin et al. (1963) that 8 out of 11 such children aged 5 months to 10 years had neutralizing antibody titres to rubella virus-six in high titre, two in titres of 4-and three children had no demonstrable antibody. The question that naturally arose from these findings was whether this antibody represented residual maternal antibody or whether it was actively produced. There seemed to be no reason why maternal antibody should persist for a longer period in rubella than in any other virus disease in which antibody passively transferred across the placenta disappears during the first six months of life. These results suggested, therefore, that antibody had been actively produced and that the foetus exposed to rubellavirus antigen in utero is not rendered immunologically tolerant. These sera were tested for neutralizing antibody by means of the interference-inhibition test in vervet-monkey-kidney cells as described by Parkman et al. (1962). Recently McCarthy et al. (1963) described an alter...

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The ratio of disc to macula/disc diameter is characteristically increased in eyes with optic nerve hypoplasia. We present the largest reported series of patients with a definitive diagnosis of optic nerve hypoplasia for whom this ratio has been determined. Ali measurements were made by an independent masked observer. Our Underdevelopment of one or both optic nerves is a common anomaly.' The aetiology is unknown. Optic nerve hypoplasia (ONH) is a diagnosis which should be considered in any person with poor vision for which there is no immediately apparent explanation. Although the small optic disc of ONH is easily detected in severe cases, more subtle forms of the disorder may present more difficulty. The differential diagnosis includes the apparently small optic nerve head of hypermetropia. Subtle forms of the disorder may be difficult to distinguish from normal appearances. Red-free fundus photography can aid in this differentiation by detecting evidence of nerve fibre layer defects which correspond with that of the pattern of visual field loss.2 However, many cases of ONH do not show such focal defects and are manifest solely as a uniformly thin nerve fibre layer within affected areas, which makes the condition more difficult to define than focal defects.3Franceschetti and Bock4 measured the optic disc diameter by means of focal illumination of the fundus, using contact lens biomicroscopy and a micrometer scale. Estimation of the size of the optic disc by comparing the slit beam width on the Hagg-Streit 900 slit-lamp with the optic disc diameter on contact lens biomicroscopy has also been advocated.5 These relative measurements are useful in comparing the diameter of the optic disc relative to the slit-lamp beam or the scale, because their magnification when projected on the optic disc is assumed to be the same as the magnification of the optic disc, as the slit beam and microscope optics are parfocal and both pass through the optical system of the eye.Other methods which have been described include comparison of the size of the optic disc with the size of the whole area of the fundus as seen in the standard fundus photograph,' measurement with a scale over the frontal lens during indirect ophthalmoscopy,7 direct measurements of the orbital part of the optic nerve by CT scanning,8 A-scan ultrasonography,8 and B-scan ultrasonography.9Variations in the size of the eye with concomitant differences in dioptric power even in emmetropic eyes render absolute measurement of intraocular structures difficult.'0" Interference fringes provide a means of accurate measurement' but necessitate sophisticated equipment and a co-operative patient. The alternative is to make relative measurements from fundus photographs. The apparent size of the optic disc in fundus photographs is influenced by several factors, including the axial length, corneal curvature, and the shape of the fundus,"3 and by refractive errors and optical aberrations, but because all photographed structures are equally influenced by anatomical and re...

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