Intellectually disabled adults have an high incidence of visual problems and they are often unable to communicate their visual difficulties. At Lennox Castle and Waverley Park Hospitals, vision care is through referral by medical and nursing staff to designated optometrists and ophthalmologists. This practice has provided a good service when visual difficulties are noticed. The vision care requirements of all residents had not been comprehensively assessed and a new interdisciplinary procedure developed at Waverley Park Hospital had drawn attention to the fact that only 11% had been offered vision assessment within the previous 5 years. In this study, 63 residents without specific referral received a comprehensive visual and medical assessment. The residents ranged from age 20 to 85 years and included the full range of disabilities. Objective assessments, ophthalmoscopy and retinoscopy were generally successful for all levels of disability. Visual acuity and visual fields were tested using methods suitable for nonverbal subjects. Success rates for these subjects were generally good, except in the profoundly disabled group where less than 30% were able to respond. A high prevalence of visual impairment, refractive error, squint and other ocular conditions was found. Visual impairment was most common in the severe and profoundly disabled groups because of optic nerve or cortical dysfunction. New spectacles were recommended for 23 residents (seven others had adequate correction). Nine residents were referred for ophthalmologic consultation, mainly for cataract. Three required monitoring for visual conditions. Thirty-one residents (49%) required no immediate action beyond documentation of the visual status. This study has shown a high prevalence of visual difficulties which were not previously detected. Routine biennial vision assessment of all residents is recommended to allow timely intervention to correct vision problems, and also to provide the necessary information about vision to plan appropriate programmes of activity.

This paper investigates gender differences in the peak latency and amplitude of the P1 component of the pattern-reversal visual evoked potential (pattern-reversal VEP) recorded in healthy term infants. Pattern-reversal VEPs in response to a series of high contrast black and white checks (check widths 120', 60', 30', 24', 12', 6') were recorded in 50 infants (20 males, 30 females) at 50 weeks post-conceptional age (PCA) and in 49 infants (22 males, 27 females) at 66 weeks PCA. Peak latency of the major component, P1, was considerably shorter in female compared with male infants. Differences in head circumference do not entirely account for the gender differences in peak latency reported here. A gender difference in P1 amplitude was not detected. These findings stress the importance of considering gender norms as well as age-matched norms when utilizing the pattern-reversal VEP in clinical investigations. Studies including a wider range of ages are clearly necessary in order to establish whether the earlier peak latencies in female infants represents a difference in the onset or rate of visual maturation

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This paper investigates the prognostic value of flash visual evoked potentials (VEPs) recorded in preterm infants at birth and at term age with respect to severe neurological outcome. Flash VEPs were recorded in 81 preterm infants at birth (i.e. <35 weeks' gestation) and repeated in 56 of these infants at term age. The preterm infants were assigned to either a healthy or at-risk subgroup based on clinical birth factors. Normal ranges of flash-VEP latencies, amplitudes, and number of components present were obtained from the subgroup of healthy preterm infants and from 68 term infants tested postnatally. The flash-VEP results of the entire preterm group were compared with the normal ranges and any abnormalities noted. Seven preterm infants in the at-risk group died, six of whom had abnormal flash VEPs before term age. Of the five infants from the at-risk group diagnosed with cerebral palsy (CP), three had abnormal flash VEPs before term age. Thus the sensitivity and specificity of the flash VEP with respect to survival was 86% and 89% respectively, and with respect to the development of CP was 60% and 92%. The abnormal features of the flash VEP associated with adverse outcomes comprised a delayed N3 component before term age and the absence of a positive component (P2) at term age.