The effects of aging vitreous on contrast sensitivity function

Area of Science:

• Ophthalmology
• Vision Science
• Gerontology

Background:

• Contrast sensitivity function (CSF) naturally declines with age.
• Previous research suggested macular ganglion cell complex (GCC) thinning as a cause for age-related CSF decline, excluding cataracts.
• Alternative hypotheses linked CSF decline to increased vitreous echodensity and posterior vitreous detachment (PVD).

Purpose of the Study:

• To investigate the relationship between CSF, vitreous echodensity, PVD, and GCC thickness in relation to aging.
• To determine the independent contributions of PVD, vitreous echodensity, and GCC thickness to age-related CSF changes.

Main Methods:

• Evaluated age, CSF (Weber index), vitreous echodensity (quantitative ultrasonography [QUS]), lens status, best-corrected visual acuity (BCVA), and GCC thickness (SD-OCT) in 57 subjects.
• Subjects were categorized into groups with (n=32) and without (n=25) PVD.
• Multivariate linear regression analysis was employed to identify independent predictors of CSF.

Main Results:

• CSF was significantly worse (51.2%) in eyes with PVD compared to those without (P < 0.001).
• Vitreous echodensity was significantly higher (55.8%) in eyes with PVD (P < 0.001).
• PVD status, vitreous echodensity, and age were significant independent predictors of CSF; GCC thickness and BCVA were not.

Conclusions:

• Posterior vitreous detachment (PVD) and increased vitreous echodensity are significant determinants of diminished contrast sensitivity function (CSF), independent of age.
• In the absence of cataracts and GCC thinning, these vitreous changes are likely contributors to age-related decreases in CSF.
• Highlights the role of vitreous integrity in maintaining visual function across the lifespan.