Outcomes of congenital and infantile cataract in the United Kingdom
Congenital cataract is a rare disorder but is a priority of Vision 2020, the international programme for the elimination of avoidable blindness, reflecting its treatment potential and the consequences for the child and family if left untreated. As the aetiology of congenital cataract is unknown in the majority of cases with only a minority being preventable, informing secondary and tertiary approaches to prevent visual impairment is currently essential. The quality of life of children with congenital cataract has not previously been reported. This study was a unique opportunity to engage parents and children in the assessment of their quality of life, an important outcome. Equally, data are limited on the impact of amblyopia treatment on the psychological wellbeing of the child with congenital cataract and their families. The British Congenital Cataract Study (BCCS) cohort comprises a nationally representative group of children who at the time of the present study, have been under management for at least 6 years after diagnosis. 61% of children with bilateral cataracts achieved an acuity of at least 6/18: commonly considered the vision level at which children can be educated at mainstream schools with minimum extra help. The worst median visual acuity (6/48) was recorded in the cataractous eyes of children with unilateral cataract who underwent surgery, suggesting that despite intervention in these children, the outcome is still poor. Concordance with occlusion is the most important predictor of visual acuity of children with unilateral cataracts. Earlier surgery and concordance with occlusion are associated with better visual acuity and poorer acuity was associated with the presence of a severe cataract and other medical conditions in children with bilateral cataracts. The incidence of postoperative open angle glaucoma was 5.25 cases/100 eyes operated/year. Early age at detection is the most important factor associated with the development of glaucoma after congenital cataract surgery. The majority of parents found occlusion difficult and almost a third thought their child's behaviour had worsened. Furthermore, a third of the parents thought that the relationship with their child had worsened as a result of occlusion. Despite this, no association was found between occlusion concordance and the child's or parental experience of occlusion and the majority of parents never worried the patches were harmful. The quality of life scores of children with congenital cataract in the present study were comparable to those reported by children with childhood cancers and rheumatological disorders. This study's findings should inform future parents of children with congenital cataract especially those with unilateral cataract and have implications for resource allocation in terms of schooling and additional help. The findings also emphasise the importance of early detection to enable early surgery and the importance of occlusion to prevent amblyopia. Identification of underlying causes of difficulties with occlusion may initiate changing emphasis on the management of children with congenital cataract. Postoperative open angle glaucoma may be the price of successful screening programmes to ensure early detection and treatment of congenital cataract to mitigate against amblyopia. Further work is required to delineate precisely the optimal timing of surgery to balance the benefits of early intervention with potential risks. The finding that the quality of life of children with congenital cataract is comparable with more debilitating and life threatening disorders is unexpected and has implications for ophthalmologists regarding how they view the impact of congenital cataract on the HRQOL of these children.