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Abstract
26 patients were recruited following acute unilateral damage to the postgeniculate visual pathway (onset 12–50 years prior to testing) together with age and sex matched controls. Peripapillary retinal nerve fibre layer (RNFL) thickness was measured with optical coherence tomography on a single occasion. (2) 7 of the 26 patients and a further 4 patients with incomplete hemianopia were recruited within 5 months of the injury (range 5–177 days). In this group the RNFL thickness was measured serially for at least 43 days (range 43–876 days) to study the rate of change.
Results (1) There is a negative correlation between the RNFL thickness and time since onset of injury (n=26; R2=0.2; p=0.03). This equates to a reduction in RNFL thickness of 0.42 μm/year (cf 0.2 μm/year in normal ageing). (2) In 3/7 patients with hemianopia the RNFL thickness began to decrease within 3 months of the acute event and there is a trend to decline further over a year. In patients with homonymous quadrantanopia or scotoma no change in the RNFL thickness has been detected. We have shown previously that retrograde trans-synaptic degeneration can be detected using OCT1. The time course of this can be followed and may be useful as a model of trans-synaptic retrograde degeneration in the human brain.