Abstract
Purpose :
To characterize postnatal retinal development in infants and young children with albinism using hand-held spectral domain optical coherence tomography (HH-SDOCT)
Methods :
We obtained 181 mixed cross-sectional and longitudinal optical coherence tomograms from 44 children with a diagnosis of albinism and compared them with 297 tomograms obtained from 148 race-matched controls. The mean postnatal age at the time of examination was 37.8 months (range 0.9 - 83.6) for the albinism group and 37.7 months (range 0 - 83.3) for the control group. Retinal layer segmentation was performed manually using ImageJ. Fractional polynomial modelling was used to analyse the differences in development of retinal layers with age between the albinism and control groups.
Results :
Normal retinal development is nonlinear, continues until adolescence and involves migration of the inner retinal layers (IRLs) away from the central fovea, migration of the cone photoreceptors into the central fovea and elongation of the outer retinal layers (ORLs) over time. In comparison to controls, IRL migration from the fovea is delayed and arrests prematurely in albinism, resulting in a significantly thicker central macular thickness (p<0.0001). In contrast, the parafoveal (1000µm from the central fovea) and perifoveal (2000µm from the central fovea) retinal thicknesses were significantly decreased in albinism in comparison to controls (p<0.0001). There is evidence of ongoing foveal ORL elongation in albinism, although reduced in amplitude in comparison to controls as a result of significant reductions in the degree of elongation of the photoreceptor inner (IS) and outer segments (OS) (p<0.0001). Interestingly, the parafoveal OS measurements were significantly increased in albinism in comparison to controls (p<0.0001). The retinal pigment epithelium (RPE) increases in thickness more slowly resulting in a uniform decrease in RPE thickness across all measured retinal locations in albinism (p< 0.0001).
Conclusions :
We have demonstrated that retinal development is not arrested in children with albinism, but is ongoing albeit at a reduced rate and magnitude in comparison to controls. Potentially treatment during this crucial period of residual plasticity may promote normal retinal development and optimise visual function.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.