| Summary: | Albinism is an uncommon genetic condition characterised by hypopigmentation of the hair, skin and eyes; and is associated with reduced vision, nystagmus and high refractive errors. Currently there is discrepancy in the literature in terms of the most prevalent form of refractive error in albinism. This thesis investigates refractive development in children with albinism. As nystagmus is a common feature of albinism, a group of children with Idiopathic Infantile Nystagmus (IIN) were also recruited in order to examine the effects of nystagmus on vision and refractive error. The Northern Ireland Nystagmus and Albinism (NINA) Study began in Autumn 2008 and concluded in Winter 2011. A series of retrospective, cross-sectional, prospective and imaging studies combined to explore refractive error and visual function in 105 participants (albinism n=73, IIN n=32) aged 4.5 months to 47 years. The findings were compared to published data on visually normal children and adults. The data demonstrated the following: • The most prevalent form of refractive error in albinism is hypermetropia. • High magnitudes of with- the-rule astigmatism are commonly found in albinism. • The emmetropisation process is impaired in albinism; infantile spherical and astigmatic refractive errors tend not to decrease with increasing age. • The degree of foveal hypoplasia demonstrated in albinism is related to visual acuity; poor acuity being associated with more severe hypoplasia. • The diagnoses of several individuals recruited with IIN were re-explored subsequent to their participation.
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