Description: Looking for online definition of degeneration in the Medical Dictionary? degeneration explanation free. What is degeneration? Meaning of degeneration medical term. What does degeneration mean?
Deterioration of tissue or organ resulting in reduced efficiency. Examples. degeneration of the cornea; degeneration of the retina. See corneal dystrophy .
paving-stone degeneration Discrete, yellowish round areas of retinal thinning and depigmentation located near the ora serrata. The underlying choroid may be seen. It is a benign degeneration occurring with advancing age. Syn. cobblestone degeneration; peripheral chorioretinal degeneration.
pellucid marginal degeneration A rare condition characterized by bilateral, slowly progressive thinning and protrusion of the inferior peripheral cornea. The involved area is clear (hence the word pellucid), but the condition may be complicated by hydrops and the central cornea typically develops against the rule astigmatism. Treatment usually consists of gas permeable scleral lenses, but keratoplasty may be necessary. See corneal ectasia ; hydrops ; keratoconus .
peripheral cystoid degeneration A degenerative process in the peripheral retina that occurs almost universally in the elderly. It consists of numerous, discrete cystic spaces in the outer plexiform or inner nuclear layer presenting a frothy appearance. The degeneration starts at the ora serrata and slowly progresses to the peripheral retina. If the cysts should join together, degenerative retinoschisis develops. It is not usually associated with retinal tears. The condition does not require any treatment.
Salzmann's nodular degeneration A degenerative condition characterized by bluish-white, elevated nodules on the surface of the cornea. It may occur in people previously affected by trachoma, phlyctenular keratitis, vernal keratitis or keratoconjunctivitis sicca. Most cases are asymptomatic, but if the nodules impair vision, keratoplasty may be necessary.
tapetoretinal degeneration A hereditary degeneration affecting the photoreceptors of the retina or the pigment epithelium layer. Some authors also include the choroid. Syn. tapetoretinopathy. See choroideremia ; retinitis pigmentosa .
deterioration; change from a higher to a lower form, especially change of tissue to a lower or less functionally active form. When there is chemical change of the tissue itself it is true degeneration; when the change consists in the deposit of abnormal matter in the tissues, it is infiltration. See also wallerian degeneration. Zenker's necrosis .