Accommodation is the ability to view objects at close range. Presbyopia is the age related loss in accommodative amplitude and may be related to another aging disease – glaucoma, the onset of which parallels the age-related loss in the function of the accommodative apparatus. The Kaufman lab has uncovered stunning new information relevant to the accommodative mechanism, the pathophysiology of presbyopia and its relationship to glaucoma.
The central vitreous moves backward during the accommodative response and the ciliary muscle places accommodative tension on the optic nerve region via the choroid; suggesting an increase in pressure toward and an increase in tension on the optic nerve region. We hypothesize that these accommodative pressure and tension spikes may increase with age, which may cause damage to the ontic nerve region and may lead to optic disc cupping often seen in glaucoma patients.
During the accommodative response the posterior attachments of the ciliary muscle to the choroid pull the entire choroid and the retina forward by about 1 mm at the ora serrata (Croft et al., 2014) and 0.1 mm at the optic nerve head (Croft et al., 2014); exerting tensional forces on the elastic fiber ring and the lamina, and thereby on the optic nerve.