Introduction/Background Atypical feeding behaviours and eating restrictions are prevalent in up to 89% of children with autism spectrum disorder (ASD). Known as avoidant/restrictive food intake disorder (ARFID), children with ASD often limit their intake to specific textures, colours and appearance. This results in a highly limited diet which can lead to significant nutritional deficiencies as highlighted by NICE in their 2021 update for ASD management.

Vitamin A, an essential micronutrient, is required for the maintenance of vision (particularly in low light), integrity and function of all mucosal and epithelial tissue, growth and development and a promotional and regulatory role within the immune system. It can only be sourced within our food, derived from fruit, vegetables and animal sources which are often lacking in the diet of those with ASD. Deficiency of vitamin A can have life altering consequences. Ocular symptoms, known as xerophthalmia, span conditions such as night blindness, conjunctival xerosis and bitot’s spots are characteristic of vitamin A deficiency, to in its most severe form, rare and irreversible blindness as a result of corneal ulceration, scarring and necrosis.

Aim Through the presentation of two paediatric case studies, IM a 13 y/o female and KB an 11y/o male, we aim to highlight the risk of vitamin A deficiency in children with autism leading to irreversible loss of sight.

Subjects and Methods A retrospective review of the case notes was undertaken for IM and KB. Both children had autism and were diagnosed with irreversible visual changes secondary to severe vitamin A deficiency. Their journey from clinical presentation to diagnosis and management of their vitamin A deficiency is explored. Pervasive challenges and pertinent aspects are drawn out to raise awareness and aid future practice.

Results Both children had severely restricted diets containing no fruit or vegetables, consisting mainly of processed carbohydrates despite parents best efforts. IM presented to hospital following a collapse at home and was retrospectively found to have a 6–8 week history of deterioration in vision with a vitamin A level of 0.2 (normal range 0.8 – 2.2). KB had a rapid deterioration in vision and presented due to a change in behaviour. His vitamin A level was <0.1 and was attributed to dietary restriction. Both children found any hospital visit, particularly examination and investigations, highly distressing which created difficult barriers for their parents seeking medical attention.

Summary The nutritional challenges in children with ASD and ARFID are widely acknowledged. So too are the practical difficulties in monitoring and investigation for potential deficiencies in these patients. Nevertheless, the life altering implication of irreversible blindness caused by severe vitamin A deficiency warrants greater consideration in children with autism and hopefully preventable in future.

Conclusion All children with restricted diets and autism, even if not formally diagnosed, should undergo nutritional assessment in the community and those considered at risk warrant nutritional bloods for early diagnosis and timely intervention.