Table 2.
Ocular Parameters, Methods of Measurement, and the Impact of Aging
| Anatomical Site | Parameter | Method of Measurement | Age-Related Changes |
|---|---|---|---|
| Cornea | Corneal endothelium | Specular microscopy | Reduced cell count |
| Lens | Lens opacity | Subjective grading systems | Opacification at different sites in the lens (cataract) |
| Pentacam—lens densitometry | |||
| Retina | Retinal nerve fiber layer (RNFL) | Optical coherence tomography | Thinner RNFL |
| Retinal vessel caliber | Semiautomated retinal analysis software | Reduced diameter of arterioles and venules | |
| Retinal ganglion cells and photoreceptors | |||
| Confocal scanning ophthalmoscopy | Reduction in cone photoreceptor density | ||
| Visual function | Visual acuity | Visual acuity chart (ETDRS) | All reduced |
| Contrast sensitivity | Pelli–Robson chart | ||
| Color vision | Farnsworth–Munsell 100 hue test |
Note. ETDRS = Early treatment diabetic retinopathy study.