eyeball. Think of it as a clear window. To understand a corneal ulcer,
you must first understand how the cornea is constructed.
epithelium. This layer is comprised of many very thin layers of
cells. Below the epithelium is the stroma, and the deepest layer is
Descemetís membrane. Because all of these layers of the cornea are clear,
it is not possible to see them without special stains which colour particular
cells and highlight them when looked at with a microscope.
corneal abrasion. A corneal ulcer is an erosion through the entire epithelium
and stroma to the level of Descemet's membrane, a descemetocele exists.
If Descemet's membrane ruptures, the liquid inside the eyeball leaks out, the
eye collapses and irreparable damage can occur.
trauma. An ulcer may result from blunt trauma, such as a dog rubbing its
eye on the carpet, or due to a laceration, such as a cat scratch. The
second most common cause is chemical burn of the cornea. This may happen
when irritating shampoo gets in the eye.
and other diseases. These may originate in the eye or develop secondary to disease
weakening of the cornea which can be inherited in breeds such as the Boxer),
formation), which occurs in breeds such as the West Highland White Terrier and
diseases of the endocrine system (diabetes mellitus, hyperadrenocorticism, and
hypothyroidism).
Hey there! This is a good read. I will be looking forward to visit your page again and for your other posts as well. Thank you for sharing your thoughts about corneal ulcer. I'm glad to stop by your site and know more about corneal ulcer. Keep it up!
ReplyDeleteViral keratitis causes corneal ulceration. It is caused most commonly by Herpes simplex, Herpes Zoster and Adenoviruses. Also it can be caused by coronaviruses & many other viruses. Herpes virus cause a dendritic ulcer, which can recur and relapse over the lifetime of an individual.
Although corneal epithelium, conjunctival epithelium, and corneal fibroblasts are all capable of producing matrix metalloproteinases, including classical collagenase, abundant evidence indicates that the preeminent source of degradative enzymes which produce corneal stromal destruction in cases of corneal ulceration are delivered to the site of the corneal ulceration by neutrophils. Routine histopathologic studies and ultrastructural studies show that, regardless of the initiating stimulus for corneal ulceration, neutrophils are routinely present, in abundant numbers, and they all exhibit the ultrastructural characteristics of "activated" neutrophils. By contrast, the origin of these neutrophils, similarly, is generally underappreciated: the preocular tear film. The neutrophils have access to the damaged cornea primarily through the tears, and exclusion of the tears from the area of corneal degradation instantly arrests the ulcerative process. This was shown nearly 20 years ago in various experiments employing glued on hard contact lenses and the use of surgical adhesive itself, which provides its benefits to the ulcerating corneal not because of some sort of structural support, but rather because of a mechanical barrier to neutrophils from the preocular tear film. Indeed, histopathologic studies of such glued corneas shows essentially an acellular stroma in the affected stromal regions, whether the problem has been created by alkali burning, infectious keratopathy, an autoimmune process, or thermal burns.
Hi Jackie. Many thanks for your comments and input. Other conditions that affect the cornea include chronic superficial keratitis (pannus),keratoconjunctivitis sicca, Chronic Corneal Erosions, Scleritis/episcleritis, Corneal endothelial dystrophy, Lipid or calcium keratopathy, Punctate keratitis, Corneal neoplasms, Spontaneous chronic corneal epithelial defect (indolent ulcer or recurrent erosion).
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