Ulcerative keratitis

Severe acute and chronic allergic and inflammatory processes, keratitis, allergic corneal marginal ulcers, herpes zoster of the eye, iritis, iridocyclitis, chorioretinitis, diffuse posterior uveitis, optic neuritis, sympathetic ophthalmia, anterior segment inflammation... 

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... 

Gram-negative rods Tobramycin 3-14 mg/mL or Gentamicin 3-14 mg/mL or Ceftazidime SO mg/mL or Fluoroquinolones 3 mg/mL Less severe keratitis may use less frequent dosing Antibiotics may be alternated each hour for ulcers and contact lens... 

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. 

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. 

Only solutions of lipophilic antibiotics are able to cross the external barrier of the cornea (drops) and the internal blood-retina barrier (systemic administration) to yield sufficient concentrations in the internal eye (vitreous). Keratitis and ulceration of the cornea can be treated by frequent administration of highly concentrated (fortified) antibiotic drops. In endophtalmitis, emergency vitreous aspirate and in-travitreal and subconjunctival injection of antibiotic solutions with a long half-life is the cornerstone of treatment. These solutions should be prepared by the hospital pharmacy. Empiric topical treatment of minor external eye infections consists of antibiotic containing gels or ointments. 

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). 

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. 

Mann 3 examined the records of 84 men described as suffering from "delayed mustard gas keratitis." This group had been treated at the Contact Lenses Clinic at Moorfields, England. The eye injuries were described as "typical mustard gas scars with corneal degeneration." Mann found a low incidence of onset of trouble in the early postwar years, with a sharp rise in 1931 and peaks in 1934 and 1937 (Figure 4-1). Most, 19-23 yr old when gassed, were about 33-37 when the eye trouble peaked. The onset of symptoms was commonly provoked by minor eye injuries and followed by ulcers that tended to recur spontaneously and cause steady diminution in visual acuity. These men were all fitted with contact lenses. About half were able to wear them with improved vision the others varied from partial success to total failure. Even those helped most, however, suffered slow deterioration of visual acuity. 

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. 

Bacterial keratitis is one of the most frequent ophthalmic infections. In a meta-analysis of publications from 1950 to 2000, the use of a topical glucocorticoid before the diagnosis of bacterial keratitis significantly predisposed to ulcerative keratitis in eyes with preexisting corneal disease (OR = 2.63 95% Cl = 1.41, 4.91). Previous glucocorticoid use significantly increased the risk of antibiotic failure or other infectious complications (OR = 3.75 95% Cl = 2.52, 5.58). The use of glucocorticoids with an antibiotic for the treatment of bacterial keratitis did not increase the risk of complications, but neither did it improve the outcome of treatment. 

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

Gastroenteritis Multiple petechiae Anaphylactic syndrome Congestion, liver, spleen, lung Hemorrhage, pancreas Ulcerative colitis Keratitis, chronic Conjunctivitis, lymphocytic... 

In addition to opacification, additional comeal effects from particulate CN exposure include possible penetration of the comeal stroma, severe scarring and ulceration, and deficits in the comeal reflex (Blain, 2003 Scott, 1995). Penetration of the comeal stroma may lead to stromal edema and later vascularization, resulting in further ocular complications. These may include pseudopterygium, infective keratitis, symblepharon, trophic keratopathy, cataracts. 

Topical itraconazole appears effective in treating superficial, less severe fungal ulcers. Itraconazole may be less effective than natamycin for treating Fusarium keratitis. 

In its mild form ocular surfece disease (OSD) may cause intermittent patient discomfort with symptoms of burning, itching, and blurring of vision. At its most severe the condition may precipitate secondary keratitis and conjunctivitis, corneal ulceration and scarring, and permanent vision loss. Up to one-fourth of all adults in the United States are affected by OSD. Fortunately, in most the condition is mild to moderate, and with proper diagnosis and treatment these patients can maintain comfortable clear vision and good ocular health. 

Both conditions can cause a wide range of symptoms, the most common a foreign body sensation and a red irritated eye. Severe or debilitating symptomatology is a result of corneal surface damage, including corneal abrasion and superficial punctate keratitis. Corneal hypoesthesia with subsequent neurotrophic ulceration is also possible. 

Messmer EM, Foster CS.Vasculitic peripheral ulcerative keratitis. Surv Ophthalmol 1999 43 379-396. 

Long-term use of prophylactic antibiotics has been associated with an increased risk of ulcerative keratitis in patients with bullous keratopathy. This may simply be secondary to a relatively increased use of prophylactic antibiotics in these patients who are more susceptible to developing infectious keratitis, or it is also possible that there is an increased risk of developing colonization with antibiotic-resistant bacteria. To diminish this possibility, prophylactic antibiotics should only be used when epithelial breaks are present.Topical corticosteroid use is also a strong risk fector for the development of ulcerative keratitis and should be avoided. 

Band keratopathy was first described in 1848 and is a chronic degenerative condition characterized by the deposition of calcium carbonate salts in the superficial corneal layers, most frequently in the interpalpebral area. Although there are many reported cases of idiopathic band keratopathy, some of which seem to have a hereditary component, the most common causes are associated with chronic ocular inflammation and systemic conditions resulting in altered calcium metabolism. Band keratopathy is typically seen in eyes with chronic uveitis, severe superficial keratitis, corneal ulcers, chemical burns, interstitial keratitis (IK), trachoma, phthisis bulbi, and prolonged glaucoma. The chronic anterior uveitis of juvenile idiopathic arthritis is frequently associated with band keratopathy, with one study reporting its development in 66% of patients with juvenile idiopathic arthritis. 

It is important to differentiate between true infection of the corneal tissue and CIE (Table 26-4). The examiner must look for signs of bacterial corneal ulcers such as discharge or anterior chamber reaction and evaluate the patient s history for risk fectors known to be associated with bacterial keratitis.These risk fectors include extended wear of contact lenses, contaminated ophthalmic solutions, poor personal hygiene, diabetes melhtus, recent... 

The fluoroquinolones have advantages over combined fortified antibiotic therapy. They are considered by many to be an excellent choice for initial treatment of non-sight-threatening ulcerative keratitis. They are readily available as commercially prepared medications that do not need to be fortified to be effective. As a result, there is less chance of contamination and less epithelial toxicity compared with fortified drops. Their wide spectrum of activity allows the patient to use only one medication, and, when compared with fiartified antibiotics, they cause less discomfort upon instillation and are also less expensive.These attributes may increase patient compliance. 

Ciprofloxacin, which is available in an aqueous 0.3% ophthalmic solution and an ointment farm, has a broad spectrum of action. Ciprofloxacin has been shown to be at least as successful in treating corneal ulceration as fortified antibiotics however, as mentioned earlier, there appears to be an increasing number of resistant strains since its introduction. The usual dosage of ciprofloxacin solution for the treatment of bacterial ulcers is two drops every 15 minutes for 6 hours, then two drops every 30 minutes for 18 hours, followed by two drops every hour for 24 hours. Ciprofloxacin is then used every 4 hours for the next 12 days. Ciprofloxacin ointment also is effective in the treatment of bacterial keratitis. It is applied every 1 to 2 hours in the first 2 days and then every 4 hours for the next 12 days. 

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