Sense organs: The eye and the ear, Pathology Flashcards
Astigmatism
Defective curvature of the cornea or lens of the eye
-This causes light rays to be unevenly and not sharply focused on the retina, so that the image is distorted
Hyperopia (hypermetropia)
Farsightedness
myopia
Nearsightedness
Presbyopia
Impairment of vision as a result of old age
Cataract
Clouding of the lens, causing decreased vision
-degenerative eye disease (protein in the lens aggregates and clouds vision) and is often linked to old age but not always
Chalazion
Small, hard, cystic mass (granuloma) on the eyelid
-formed as a result of chronic inflammation of a sebaceous gland along the margin of the eyelid
Diabetic retinopathy
Disease of the retina caused by diabetes mellitus
- retinal effects include microaneurysms, hemorrhages, dilation of retinal veins, and neovascularization in the retina
- Macular edema: occurs as fluid leaks from blood vessels into the retina and vision is blurred
- Exudates (fluid leaking from the blood) appear in the retina as yellow-white spots
Glaucoma
Increased intraocular pressure results in damage to the retina and optic nerve with loss of vision
- Intraocular pressure is elevated because of the inability of aqueous humor to drain from the eye and enter the bloodstream. Normally, aqueous humor is formed by the ciliary body, flows into the anterior chamber, and leaves the eye at the angle where the cornea and the iris meet.
- diagnosed by means of Tonometry
- acute glaucoma: extreme ocular pain, blurred vision, redness of the eye, dilation of the pupil. if untreated can cause blindness
- Chronic glaucoma: may produce no symtoms intially. May experience a gradual loss of peripheral vision, with headaches, blurred vision, and halos around bright lights , or they may experience no symptoms at all
Blepharitis
inflammation of eyelid, causing redness, crusting, and swelling along lid margins
Chalazion
Granuloma formed around an inflamed sebaceous gland
Dacryocystitis
blockage, inflammation, and infection of a nasolacrimal duct and lacrimal sac, causing redness and swelling in the region between the nose and the lower lid
Ectropion
Outward sagging and eversion of the eyelid, leading to improper lacrimation and corneal drying and ulceration
Entropion
Inversion of the eyelid, causing the lashes to rub against the eye; corneal abrasion may result
Hordeolum (stye)
small, superficial white nodule along lid margin due to infection of sebaceous gland
Ptosis
Drooping of upper lid margin from neuromuscular problems or trauma
Xanthelasma
raised yellowish plaque on eyelid caused by lipid disorder
Hordeolum (stye)
Localized, purulent, inflammatory staphylococcal infection of a sebaceous oil producing gland in the eyelid
Macular degeneration
Progressive damage to the macula of the retina
- one of the leading causes of blindeness in the elderly
- severe loss of central vision
- Dry form: marked by atrophy and degeneration of retinal cells and deposits of clumps of extracellular debris, or drusen. No standard treatment
-Wet form: results from development of new (neovascular) and leaky (exudative) blood vessels close to the macula. Treatment.