title: Retinal development in albinism: a prospective study using optical coherence tomography in infants and young children.
abstract: BACKGROUND
  Retinal development normally involves migration of the inner retinal layers away from the fovea, migration of the cone photoreceptors into the fovea, and elongation of the photoreceptors over time. This process is arrested prematurely in albinism. However, because retinal development continues at least until the age of 4 years, when development arrests in albinism is uncertain. In this study we outlined the time course of retinal development in children with albinism.
  
  
  METHODS
  We studied 44 children with a diagnosis of albinism and 223 control participants. All participants were aged between 0 and 6 years. We obtained 219 mixed cross-sectional and longitudinal optical coherence tomography examinations in the albinism group and compared them with 558 control examinations. Retinal layer segmentation was performed with ImageJ software. Generalised linear mixed regression modelling was used to analyse group differences in retinal development.
  
  
  RESULTS
  In the albinism group, inner retinal layer migration from the fovea was delayed and arrested prematurely, resulting in a significantly thicker central macular thickness than in the control group (p<0·0001). Whereas the central macular thickness increased with age in the control group, in the albinism group it initially decreased with age as a result of continuing regression of the inner retinal layers (p=0·041). The perifoveal retinal thickness was significantly decreased in albinism from a reduction of both inner (p<0·0001) and outer (p<0·0001) retinal layer thicknesses. There was evidence that the photoreceptor layers across the fovea were elongating in albinism, albeit at a reduced rate, compared with the control group. This difference was most apparent for the foveal photoreceptor inner segment (p=0·001).
  
  
  CONCLUSIONS
  Our findings show that perturbations exist in several aspects of retinal development including the migration and differentiation of the neuronal cells within the retina. We showed continuing regression of the inner retinal layers and elongation of the photoreceptor layers suggesting residual plasticity of the developing albino retina. This finding is important because treatment at the earliest stages of the condition might normalise retinal development and optimise vision.
  
  
  BACKGROUND
  UK Medical Research Council (grant number MR/J004189/1), Ulverscroft Foundation, National Eye Research Centre, Nystagmus Network UK.
authors: Department of Ophthalmology, University of Leicester, Leicester, UK. Electronic address: hl146@leicester.ac.uk.
authors: Helena
authors: H
authors: Lee
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Ravi
authors: R
authors: Purohit
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Viral
authors: V
authors: Sheth
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Eleni
authors: E
authors: Papageorgiou
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Gail
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authors: Maconachie
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Rebecca J
authors: RJ
authors: McLean
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Aarti
authors: A
authors: Patel
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Anastasia
authors: A
authors: Pilat
authors: Department of Ophthalmology, Leicester Royal Infirmary, Leicester, UK.
authors: Samira
authors: S
authors: Anwar
authors: Department of Ophthalmology, Leicester Royal Infirmary, Leicester, UK.
authors: Nagini
authors: N
authors: Sarvanathan
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Frank A
authors: FA
authors: Proudlock
authors: Department of Ophthalmology, University of Leicester, Leicester, UK.
authors: Irene
authors: I
authors: Gottlob