Jonathan Crowston, Vicki Chrysostomou,Nicole Van Bergen, Eamonn Fahy, Ian Trounce

Purpose:
Age-related prevalence and incidence ofglaucoma rises almost exponentially with increasingage. The reasons for this are currently not clear. Toaddress the potential that the ageing optic nervebecomes increasingly vulnerable to injury induced byglaucoma risk factors such as IOP elevation, we devel-oped an optic nerve stress to determine whetherageing alters RGC recovery after injury and whetherthis recovery is amenable to intervention.

Methods:
A short term optic nerve injury, thatinduces selective loss of inner retinal function, wasdeveloped in anaesthetised mice of varying ages. Innerretinal function was measured using components ofthe full field ERG in light or dark-adapted eyes.. Wethen assessed the impact of diet restriction and exerciseon optic nerve recovery after injury.

Results:
Older mice displayed impaired recovery ofinner retinal function following an acute IOP injurythat per-se induces little cell death. Improved recoverywas seen in 12-month old mice subject to either diet-restriction or exercise. Improved functional outcomeswere strongly associated with reduced oxidative stressand limited microglial activation and proliferation.Both diet restriction and exercise significantly im-proved inner retinal function and reduced microglialactivation after injury.

Conclusion:
Old mice have impaired functionalrecovery after IOP injury. RGC functional recovery isstimulated by diet restriction and exercise indicatingthat the negative impacts of ageing are amenable tointervention.