Cornea trauma

Evaluation reveals an edematous, thickened, usually hazy cornea with bullae (Figure 26-12). Some areas of the cornea stain with NaFl due to ruptures of the bullae. Focal involvement of the cornea is possible, especially if there has been local disruption such as birth trauma or foreign body injury. 

Approximately 42% to 64% of RCEs occur after superficial trauma to the cornea. Fingernail injuries are reported to be the most common cause of traumatic RCE. Other causes of traumatic RCE include injuries from paper, cardboard, vegetative material, contact lenses, foreign body removal, and trauma to the epithelium during LASIK. 

Modified from Arffa RC. Corneal trauma. In Grayson s diseases of the cornea, ed. 4. St. Louis, MO Mosby, 1S>97 685-708. 

A wide range of substances that are toxic to the cornea may produce epithelial insult known as toxic keratitis. This terminology is generally reserved for mild superficial corneal irritation after contact with a harmful substance. Solutions foreign to the eye that commonly cause toxic keratitis include shampoos, lotions, and chlorinated pool water. Toxic corneal reactions have been reported from tonometer tips contaminated with 70% isopropyl alcohol or hydrogen peroxide that was not fully removed after disinfection of the probe. Irreversible corneal scarring has resulted from inadvertent ocular contamination with chlorhexidine gluconate, a skin cleanser used preop-eratively. The mistaken use of nonophthalmic products for eyedrops may result in various forms of corneal trauma. 

We paid particular attention to the study of physiological and therapeutic effects of silatranes and silocanes on one of the thinnest and most complicated varieties of cormective tissue — cornea. Silatranes effect on cornea was studied after mechanical trauma, and after alkaline and acidic bums. We also studied the effect of silocanes in healing tests with wounds and bums. 

In animals of the control and experimental groups after eye treatment with 0.5% dicain solution, a mechanical trauma in the central part of the cornea was produced by a trepan. Wound depth achieved was half of the corneal thickness diameter was 4 mm. 

Animals of the control group received physiological salt solution according to the same scheme. Histological studies of cornea were carried out on the next, fifth, tenth, twenty-fifth, and sixtieth days after trauma. Treatment of sections was conducted by conventional histological methods. 

A feature of the traumatized rabbit cornea after receiving CMS was the intact state of the back epithelium even offsite to the wound defect. Intervals between collagen fiber fascicles of the active substance of the cornea in the trauma zone were considerably marked, in spite of the chemosis. In the fi-ontal epithelium at the lips of the side walls, intensive cell growth was observed. Among the keracyte (fibroblasts) in the area of trauma and in the adjacent zone, particularly, cells in mitosis were observed more often than in the control ones. 

The feature of traumatized animal cornea treated by CMS was almost normal recovery of most of the peripheral zone structure, which demonstrated the intensification of regeneration processes. Anisomorphy of epithelial regenerate was evidently expressed in the vertical state its surface was smooth. Collagenic fibers and their fascicles were arranged in order cornea itself was without chemosis. Newly formed tissue structure of central trauma sites was less differentiated than that of peripheral ones. In this case, epithelium and regenerated cornea itself (in comparison to control) had a more regulated stmcture. 

Obtained data demonstrate that dropping 0.8% aqueous CMS solution (pH 5.5 - 6.0) into eyes afler corneal trauma intensifies inflammatory reaction and activates early processes of elimination of necrotic tissue at the point of trauma. CMS provides limitation of pathological process development in the cornea, and everywhere stimulates processes of wound epithelization. Its use ensures histo-characteristics of the epithelium layer, and arranges orderly fibers of the corneal substance itself. This provokes full comeal recovery and prevents leukoma. 

Inflammation of the cornea is keratitis. There is severe pain with a watery discharge and photophobia. Redness is concentrated in the centre of the eye. It may result from trauma, long-term use of steroid eye drops or use of soft contact lenses. 

Cornea Disease, trauma Epithelial e-PTEE, PMMA, PVA Repair, replacement Elasticity, refractive properties, transparency, curvature [14]... 

Topically applied ophthalmic drugs are used for their local effects (see Chapter 63) requiring absorption of the drug through the cornea corneal infection or trauma thus may result in more rapid absorption. Ophthalmic delivery systems that provide prolonged duration of action (e.g., suspensions and ointments) are useful, as are ocular inserts providing continuous delivery of drug. 

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