Corneal ulceration

Levinson, R.A., Patterson, C.A. and Pfister, R.R. (1976). Ascorbic acid prevents corneal ulceration and perforation following experimental alkali burns. Invest. Ophthalmol. 15, 986-992. 

Pfister, R.R., Haddox, J.L. and Lank, K.M. (1988). Citrate or ascorbate/citrate treatment of established corneal ulcers in the alkali injured rabbit eye. Invest. Ophthalmol. Vis. Sci. 29, 1110-1115. 

Blunt trauma to eye Macular edema Retinal detachment Sudden congestive proptosis (bulging of eye forward) Corneal ulcer Corneal abrasion... 

Treat acute bacterial conjunctivitis with broad-spectrum antibiotics. Although the condition is usually self-limiting, antibiotic treatment decreases the spread of disease to other people and prevents extraocular infection. Additionally, treatment may help decrease the risk of corneal ulceration or other complications that affect sight. Finally, treatment speeds recovery.14... 

Bacterial keratitis is a broad term for a bacterial infection of the cornea. This includes corneal ulcers and corneal abscesses. The cornea in a healthy eye has natural resistance to infection, making bacterial keratitis rare. However, many factors predispose a patient to bacterial infection by compromising the defense mechanisms of the eye (Table 60-5).19... 

If a patient presents with visual loss, moderate or severe pain, corneal ulceration, or a lack of response to therapy, refer the patient to an ophthalmologist for prompt evaluation... 

Exposure of rats to 800 ppm for 15 minutes was fatal, but nearly all survived when exposed for 13 minutes. There was severe inflammation of all exposed mucosal surfaces, resulting in lacrimation, corneal ulceration, and burning of exposed areas of skin. In another study, exposure of rats to 480 ppm for 40 minutes or to 96ppm for 3.7 hours was fatal in the latter group, effects were pulmonary edema and marked irritation of the bronchial mucosa. Chronic exposure of dogs and rats to about Ippm, 6 hours/day for up to 6 months caused severe pulmonary irritation and some deaths. ... 

Exposure for a short period of time to mist or diffused spray may cause stinging of the eyes and lacrimation. Splashes of the liquid in the eyes may cause severe damage including ulceration of the cornea there may be a delayed appearance of damage to the eyes, and corneal ulceration has, on rare occasions, appeared even a week or more after exposure. ... 

Infections Treatment of superficial ocular infections involving the conjunctiva or cornea (eg, conjunctivitis, keratitis, keratoconjunctivitis, corneal ulcers, blepharitis, blepharoconjunctivitis, acute meibomianitis, dacryocystitis) caused by strains of microorganisms susceptible to antibiotics. 

Instill 1 drop onto the cornea of the affected eye(s) every 2 hours while awake for a maximum daily dosage of 9 drops until the corneal ulcer has completely... 

Vitamin A deficiency can result from insufficient dietary intake, from malabsorption and it has been recognized that also malfunction of RAR-receptors can lead to symptoms of vitamin A deficiency. These symptoms include skin lesions, night blindness, corneal ulcerations and conjunctivitis and poor bone remodeling. Vitamin A deficiency associated with malnutrition is wide spread in large parts of the world and may be fatal in infants and young children suffering from kwashiorkor or marasmus. 

Infections of the external eye (the eyelids and conjunctiva or cornea) conjunctivitis, keratitis, corneal ulcer are distinguished from intra-ocular infections. The latter include infection of the vitreous (endoph-talmitis), uveitis and retinitis. Orbital and periorbital infections are often due to complications of sinusitis. 

In developing countries, trachoma caused by Chlamydia trachomatis is a recalcitrant form of chronic conjunctivitis that can cause scarring. Endophtalmitis is more frequently seen due to neglected corneal ulceration caused by trauma. 

L B. Supplement with vitamin A. Vitamin A deficiency symptoms include night blindness that can lead to corneal ulceration. This deficiency can occur in patients with impaired liver storage or fat malabsorption. Dairy products, such as milk, are a good source of vitamin A. (3-Carotene, a vitamin A precursor, is found in pigmented vegetables, such as carrots. When a deficiency is diagnosed, it is appropriate to treat the patient with a supplement rather than to rely on increased consumption of vitamin A-rich foods. A patient with pancreatic disease and malabsorption syndrome will need parenteral supplementation. 

Treatment of corneal ulcers, conjunctivitis and other superficial infections of the eye, pro-phylaxis after injuries to the eye/removal of foreign bodies, adjunctive therapy for trachoma and inclusion conjunctivitis Ophthalmic Solution l-Sdropstolowerconjunc-tival sac q2-3h. Seborrheic dermatitis, seborrheic sicca (dandruff), secondary bacterial skin infections Topical Ointment Apply small amount in lower conjunctival sac 1 -4 times/day and at bedtime. 

Superficial eye infections, including blepharitis, conjunctivitis, keratitis, and corneal ulcers Ophthalmic Ointment Usual dosage, apply a thin strip to conjunctiva q8-I2h (q3-4h for severe infections). Ophthalmic Solution Usual dosage, 1-2 drops in affected eye q4h (2 drops/hrfor severe infections). 

Herpes simplex virus ocular infections-. Ophthalmic 1 drop onto cornea q2h while awake. Maximum 9 drops/day. Continue until corneal ulcer has completely reepithe-lialized then, 1 drop q4h while awake (minimum 5 drops/day) for an additional 7 days. 

Its garlicky odor, faint at first, Is soon imperceptible. Exposure to H does not cause Immediate discomfort rather, the onset of effects Is delayed and insidious. Troops have been known to remain In contaminated areas until their eyes, skin, and respiratory organs were affected. Exposure of skin produces erythema, then blisters that are painful and slow to heal. Such eye Injuries as conjunctivitis, keratitis, and corneal ulcers cause temporary or permanent blindness. The respiratory effects of H Include rhinitis, laryngitis, bronchitis, and, In severe cases, destruction of mucous membranes. The bone marrow and digestive system are affected by systemic administration of H. The multiple effects of this Insidious agent make It among the most potent used on the battlefield. 

The acute pathologic effects of H on the eye include edematous clouding of the cornea and necrosis of corneal stroma. About 5 h later, infiltration by segmented leukocytes is noted at the sclero-comeal junction and in the corneal stroma. Healing usually occurs in several weeks, but the Injury may result in persistent or recurrent corneal ulceration and blindness. 

Of the long-term complications of wartime exposure to mustard gas, perhaps the best documented and one of the most serious is recurring corneal ulcers, with eventual opacification and blindness. No exact figures are available for predicting the eventual development of such long-term corneal lesions, but it has been reported that a Ct of 100 mg min/m will cause acute blindness for 24-48 h.20 Permanent blindness typically occurred about 14 yr... 

Owens and Punte3 tested CS solutions in rabbits and monkeys by dropping 0.2 ml of 1% CS in dipropylene glycol into one eye of each rabbit or monkey, the other eye serving as a control. Six animals were used in each test. Conjunctival redness and swelling lasted for 1-3 d. The experiment was repeated, but with applications of 0.2 and 0.05 ml on 5 successive days. The 0.2-ml applications produced conjunctivitis, iritis, severe chemosis, and corneal ulceration. The 0.05-ml applications resulted in conjunctivitis, moderate chemosis, and iritis. These conditions had all cleared 7-10 d after the last dose. Rabbits and monkeys had qualitatively similar symptoms, but they were less severe in the monkeys. 

In other acute-duration studies, groups of 4 male albino ChR-CD rats were exposed to 30 ppm HDI for 4 hours daily for 10 days over a 2-week period. A slit-shaped opacity of the cornea (clinically interpreted to be a corneal ulcer) of one eye was reported in one rat that died after exposure had ended (Haskell Laboratory 1961). In another study, male rats (strain not specified) were exposed for 6 hours to an unknown air concentration of HDI. The investigators estimated that 0.4% of the HDI in a bubbler was potentially evaporated, but total air flow through the chamber was not measured, so that it is not possible to precisely calculate the air concentration of HDI inhaled by the test animals. Animals were observed for behavioral changes for 10 days after exposure. All animals survived exposure and the 10-day observation period. The authors concluded that HDI was mildly toxic. The fumes were moderately irritating to the conjunctiva of the eye soon after the start of exposure (Mobay Corporation 1966). 

Local or topical administration of amphotericin has been used with success. Mycotic corneal ulcers and keratitis can be cured with topical drops as well as by direct subconjunctival injection. Fungal arthritis has been treated with adjunctive local injection directly into the joint. Candiduria responds to bladder irrigation with amphotericin B, and this route has been shown to produce no significant systemic toxicity. 

Fig. 7.8 Inferior corneal ulceration displayed by fluorescein with, opposite, a conjunctival ischemia also marked nasally...

Transcorneal iontophoresis of antibiotics for the treatment of corneal ulcers offers a potentially effective method of management. Numerous studies have demonstrated successful penetration of antibiotics into the anterior chamber after iontophoretic treatment, compared with topically eyedrop instillation of the drug [42,58,59,66,67], The efficacy of the treatment was investigated in rabbit eyes after intrastromal injection of Pseudomonas. Gentamicin, tobramycin, and ciprofloxacin iontophoresis resulted in significantly fewer bacterial colonies in the cornea compared with frequent eyedrops instillation [68-71],... 

Ethylmorphine hydrochloride (Dionine ) resembles codeine more closely in its action than it does morphine. It is used primarily as a chemotic to produce vasodilatation and edema of the conjunctiva in corneal ulcer and other inflammatory conditions of the eye. For this purpose, it is instilled topically as a 1 to 5% solution in the eye. It has also been used as an antitussive in doses of 15 mg. 

Corneal Ulcers-Keratitis Pseudomonas aeruginosa Killed 5 ppm... 

Toxicity Dimethylamine induces adverse effects such as irritation to skin and lungs. Repeated exposure to the chemical has caused corneal injury in experimental guinea pigs and rabbits. Studies of Hollinger and Rowe,34 Coon et al.,35 and others36 revealed inflammatory changes in the lungs, ulcerative rhinitis, nasal turbinates, and corneal ulceration in laboratory rabbits and nonhuman primates. 

X3A Corneal ulceration/keratomalacia Formation of holes on the cornea (involving less than a third of corneal surface)... 

X3B Corneal ulceration keratomalacia Cornea becomes cloudy and soft (involving a third or more of the corneal area)... 

---