What is conjunctival Keratinization?
Keratinization of the tarsal conjunctiva in an eye with adequate tears occurs following a number of conditions, including irritation and sensitivity to topical medications, Stevens-Johnson syndrome, radiation to the lid, and occasionally from unknown causes.
What causes conjunctival folds?
In most instances, conjunctivochalasis is believed to be triggered by the natural age-related thinning and stretching of the conjunctiva, which is the mucous membrane that covers the front of the eye and lines the inside of the eyelid.
What is limbal dermoid?
Limbal dermoids are benign congenital tumors that contain choristomatous tissue (tissue not found normally at that site). They appear most frequently at the inferior temporal quadrant of the corneal limbus. However, they may occasionally present entirely within the cornea or may be confined to the conjunctiva.
What is a conjunctival dermoid?
Dermoid cysts are the most common orbital tumor of childhood and are seen as a painless, superotemporal mass that frequently erodes adjacent bone. In contrast, conjunctival dermoid cysts are believed to result from embryonic sequestration of conjunctiva.
Does vitamin A deficiency cause Keratinization?
More severe deficiency results in corneal keratinization, ulceration, and necrosis. Vitamin A is necessary for normal differentiation of nonsquamous epithelium; keratinization is a direct consequence of its deficiency.
What is Keratinisation skin?
Keratinization, also termed as cornification, is a process of cytodifferentiation which the keratinocytes undergo when proceeding from their post germinative state (stratum basale) to finally differentiated, hardened cell filled with protein, constituting a structurally and functionally distinct keratin containing …
How common is conjunctivochalasis?
Conjunctivochalasis, an age-dependent, bilateral condition of redundant conjunctiva, is seen in over 98 percent of individuals over the age of 60.
Can dry eyes cause subconjunctival hemorrhage?
Dry eye symptoms, in conjunction with recurrent subconjunctival hemorrhages should prompt one to consider conjunctivochalasis as a potential cause. Furthermore, rather than disregarding the condition as a normal aging change, it is important to recognize that surgery may alleviate symptoms and provide long term relief.
What is a Dermolipoma?
A common form of congenital dermoids: tumor-like lesions that are present at birth and may or may not enlarge over time. Composed of normal elements which are not normally found at the site of development.
What happens to the hair during the keratinization process?
The hair dies, shrinks, becomes finer and usually becomes lighter in color, but remains attached to its follicle while the bulb is dormant. At the end of this rest period, the hair is pushed out of the scalp by the new hair shaft growing in and beginning its own hair cycle.
How does shrinkage of the conjunctiva cause symblepharon formation?
Further, shrinkage of the conjunctiva leads to shallowing of the canthal recesses, loss of canthal structures, forniceal foreshortening, and symblepharon formation ( Figure 1 ).
What does it mean when keratinocytes differentiate into corneocytes?
Keratinization. Keratinization is defined as cytoplasmic events that take place in keratinocytes that move through the different layers of the epidermis to finally differentiate into corneocytes.
Which is the most common cause of cicatrizing conjunctivitis?
Since then, a number of medications have been reported to cause cicatrizing conjunctivitis. The vast majority are topical glaucoma medications. The most commonly implicated drugs are epinephrine, echothiophate iodide, pilocarpine, idoxuridine, and timolol.