Reticular peripheral cystoid degeneration is similar to TPCD with the exception that the cystoid spaces are in the nerve fiber layer. choroidal vascular changes, and Bruch’s membrane thickens. Retinal vessels become hyalinized and there is a loss of rods before cones in the macula. RPE morphometric changes occur with aging. The vitreous becomes liquefied and there is a loss of vitreous compartmentalization. The sclera becomes rigid and may become calcified. The optic nerve exhibits structural changes with age. == Conclusions. == There are numerous anatomic age-related changes in the human eye. Current areas of investigation related to these changes include adaptive optics scanning laser ophthalmoscopy imaging of the RPE mosaic in the context of aging, and drug delivery devices that overcome age-related alterations to retinal and macular perfusion. Keywords:aging, anatomy, pathology == Introduction == Numerous anatomic changes occur in the eye with age. These changes generally include loss and attenuation of cells, such as the corneal endothelium and RPE; degenerative processes, such as vitreous liquefaction; and accumulations of materials, such as drusen. There are research opportunities to image the effects of aging, thus, predicting diseases that are characterized by abnormal or premature aging as well as understanding the effects of aging on therapeutic drug delivery to arrest ocular disease. == Cornea == As the eye ages, the cornea flattens.1The thickness of Bowman’s layer, 8 to 10 m, remains constant throughout life. There is a tendency for calcific deposition at the periphery of Bowman’s layer with aging. Arcus senilis, a deposition of lipid near the limbus, also may occur with aging. The stromal keratocyte density appears higher in children than adults. Arcus senilis appears in the peripheral cornea with aging in some patients.2The thickness of Descemet’s membrane increases with aging.3There is a LysoPC (14:0/0:0) decrease in corneal endothelial cell density that occurs with aging.4The most precipitous decrease in cell density occurs in the first five years of life. In general, the corneal endothelial cell density decreases from approximately 5000 cells/mm2at birth to 3000 cells/mm2in older age. There is a direct correlation between histologic corneal endothelial cell number and specular microscopic endothelial cell density.5The corneal endothelial cell density is not uniform, with an increased endothelial cell density in the paracentral and peripheral regions of the cornea, which declines with age at a rate of between 0.2% and 0.6% per year.6There is some evidence that endothelial stem cells are present in a regenerative zone near Schwalbe’s line which give rise to a paracentral storage zone of cells.6,7 == Trabecular Meshwork == With age, the trabecular meshwork changes histologically from a long, wedge shape to a shorter, more rhomboidal form.8The trabeculae become progressively thickened and ultrastructural examination shows a change in the appearance of extracellular materials.8The cellularity of the trabecular meshwork decreases with age.9,10A progressive decrease in trabecular endothelial cellularity (58%) and LysoPC (14:0/0:0) absolute cell number (47%) was documented in newborns to persons aged 81 years.9This change parallels the decrease in corneal endothelial cell density and corresponds with senescence of cultured trabecular meshwork cells. 11Aqueous outflow spaces in the trabecular meshwork also decreases with age, which may account for an increase in intraocular pressure.10This is thought to be due to an accumulation of extracellular sulfated proteoglycans with accompanying changes in collagen/microfibril architecture.1214Additionally, there is an age-related reduction of giant vacuoles and intracellular pores in Schlemm’s canal.15All of these changes may result in a decrease in aqueous outflow facility. == Ciliary Body == With advancing age, the stroma of the ciliary processes becomes collagenized, the processes appear to become less vascularized, and they also appear shorter and more blunt.16The cellularity of the ciliary body appears to diminish with age16and the ciliary body smooth muscle bundles undergo age-related changes in morphology suggestive of an antero-inwards displacement of the muscle mass.17Occasionally, age-related hyperplasia of the ciliary body nonpigmented epithelium occurs and forms a Fuchs adenoma. This is a benign lesion that may CD244 occur as an incidental finding in eye bank eyes, although occasionally it clinically mimics a malignant neoplasm.18 == Lens LysoPC (14:0/0:0) == The shape of the crystalline lens in histologic sections changes with age. In infants, the lens assumes a reniform configuration, whereas in adults, it is more oval.16,19The lens increases in weight from approximately 90 mg at birth to 150 mg at age 20 years, 190 mg at age 40 years, and 240 mg at age 80 years.20Cataracts are associated with aging and are manifest with color changes in.