Structural Changes During Aging

Structural changes
Vitreous body
There is a significant structural change during aging, consisting of a transition from a clear gel in young to a fibrous structure in adults. In old age there is advanced liquefaction with thickening and tortuosity of vitreous fibers, and collapse (syneresis) of vitreous (Fig. 2.3). Postmortem studies80 found syneresis in 70% of subjects in the eighth decade. Syneresis occurs earlier and is more extensive in myopic eyes,81 and is accelerated with inflammation, trauma, and arthro-ophthalmopathies.82

Fig. 2.3 Gross appearance of posterior vitreous detachment in a phakic eye.10
Aging changes at the vitreoretinal interface
The width of the vitreous base posterior to the ora serrata increases with age to over 3.0 mm.35 There is posterior migration of the posterior border of the vitreous base with age, temporally,83 and “lateral aggregation” of the
It may begin more peripherally.76
Epidemiology
The incidence of PVD is 66% between the ages of 66 and 86 years, and 53% after 50 years,87 more common in women.76 By clinical examination, ultrasonography, and monochromatic photography have been standard, but nanotechnologies such as dynamic light scattering,88 are being developed to improve clinical evaluation. In a postmortem study155 of 786 subjects aged >20 years, an upside-down suspension-in-air technique detected a 41% incidence of PVD over 65 years of age. Of 62 aphakic eyes, 94% had partial or complete