Keratitis

Template:DiseaseDisorder infobox Template:Search infobox Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohamed Moubarak, M.D. [2], Faizan Sheraz, M.D. [3]

Overview

Keratitis is a condition in which the eye's cornea is inflamed. Superficial keratitis involves the superficial layers of the cornea. After healing, this form of keratitis does not generally leave a scar. Deep keratitis involves the deeper layers of the cornea, leaving a scar upon healing that impairs vision if on or near the visual axis. Keratitis has multiple causes, one of which is an infection of a present or previous herpes simplex virus secondary to an upper respiratory infection, involving cold sores. Symptoms of keratitis include red eyes, sensitivity to light, and uncomfortable eyes. In the later stages of more severe cases, there can be strong pain, loss of vision, blurry vision, and pus. Microbial keratitis should be managed as bacterial keratitis until proven otherwise. Steroids are indicated in the management of keratitis to reduce inflammation that may damage the eye.

Classification

Superficial keratitis involves the superficial layers of the cornea. After healing, this form of keratitis does not generally leave a scar.

Deep keratitis involves deeper layers of the cornea, leaving a scar upon healing that impairs vision if on or near the visual axis.

Pathophysiology

Keratitis has multiple causes, one of which is an infection of a present or previous herpes simplex virus secondary to an upper respiratory infection, involving cold sores.

Pathogens

• Amoebic keratitis. Amoebic infection of the cornea is the most serious corneal infection, usually affecting soft contact lens wearers. It is usually caused by Acanthamoeba. On May 25, 2007, the CDC issued a health advisory due to increased risk of Acanthamoeba keratitis (AK)infection associated with use of Advanced Medical Optics (AMO) Complete Moisture Plus Multi-Purpose eye solution. See CDC Advisory
• Bacterial keratitis. Bacterial infection of the cornea can follow from an injury or from wearing contact lenses. The bacteriums usually involved are Staphylococcus aureus and for contact lens wearers Pseudomonas aeruginosa.
• Fungal keratitis (cf. Fusarium, causing recent incidences of keratitis through the possible vector of Bausch & Lomb ReNu with MoistureLoc contact lens solution)
• Viral keratitis

• Herpes simplex keratitis. Viral infection of the cornea is often caused by the herpes simplex virus which frequently leaves what is called a 'dendritic ulcer'.
• Herpes zoster keratitis

Other

• Exposure keratitis
• Photokeratitis - keratitis due to intense ultraviolet radiation exposure (e.g. snow blindness or welder's arc eye.)
• Ulcerative keratitis
• Contact lens acute red eye (CLARE) - a non-ulcerative sterile keratitis associated with colonization of Gram-negative bacteria on contact lenses
• Severe allergic response may lead to corneal inflammation and ulceration (i.e. vernal keratoconjunctivitis).[4]
• Drug Induced - Afatinib, Cyclopentolate, Diclofenac (ophthalmic), Doxorubicin Hydrochloride, Emedastine Difumarate, Moxifloxacin ophthalmic, Naphazoline , Nitisinone, Panitumumab, Pramipexole

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Causes by Organ System

Cardiovascular	No underlying causes
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	No underlying causes
Ear Nose Throat	No underlying causes
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	No underlying causes
Genetic	No underlying causes
Hematologic	No underlying causes
Iatrogenic	No underlying causes
Infectious Disease	No underlying causes
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	No underlying causes
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	No underlying causes
Oncologic	No underlying causes
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	No underlying causes
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	No underlying causes
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	No underlying causes

Symptoms

The symptoms are often very similar to those of conjunctivitis, an inflammation of the conjunctiva, and photophobia. The eye turns very red and there may be sensitivity to light, and the eye may feel uncomfortable. In the later stages of more severe cases, there can be strong pain, loss of vision/blurriness, and pus may form.

Diagnosis

Effective diagnosis is important in detecting this condition and subsequent treatment as keratitis is sometimes mistaken for an allergic conjunctivitis.

Treatment

• Treatment depends on the cause of the keratitis.
• Microbial keratitis should be managed as bacterial keratitis until proven otherwise.
• Steroids are indicated in the management of keratitis to reduce inflammation that may damage the eye.

Antimicrobial regimens

Bacterial Keratitis

• 1. Causative pathogens

• Pseudomonas aeruginosa
• Staphylococcus epidermidis
• Staphylococcus aureus
• Streptococcus pneumoniae
• Serratia spp.
• Hemophilus spp.
• Moraxella spp.
• Neisseria gonorrhea
• Corynebacterium diphtheriae
• Listeria spp.
• Shigella spp.
• Nocardia spp.
• Mycobacterium spp.

• 2. Empiric antimicrobial therapy

• Preferred regimen (1): Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14
• Preferred regimen (2): Ofloxacin 0.3% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (3): Levofloxacin 1.5% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (4): Moxifloxacin 0.5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (5): Gatifloxacin 0.3% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (6): Cefazolin 5% q30min to q1h on day 1 then q2h on day 2 then q4h on days 3-14 AND Tobramycin 5% ophthalmic ointment q1h on day 1 then q2h on day 2 then q4h on days 3-14 OR Gentamicin 1.5% ophthalmic ointment q30min to q1h on day 1 then q1h on day 2 then q4h on days 3-14)
• Alternative regimen (1), unresponsive keratitis: Vancomycin 5% q30 min on day 1 then q2h on day 2 then q4h on days 3-14 AND Amikacin 5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Alternative regimen (2): Erythromycin 0.5% ophthalmic ointment qhs for 1 week AND (Amikacin 5% AND/OR Vancomycin 5% q30 min on day 1 then q2h on day 2 then q4h on days 3-14)
• Note (1) : Subconjunctival antibiotics may be helpful where there is imminent scleral spread or perforation or in cases where adherence to the treatment regimen is questionable.
• Note (2) : Systemic therapy is necessary for suspected gonococcal infection.

• 3. Pathogen-directed antimicrobial therapy

• 3.1 Non-streptococcal gram-positive bacteria

• Preferred regimen (1): Moxifloxacin 0.5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (2): Gatifloxacin 0.3% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (3): Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14
• Preferred regimen (4): Ofloxacin 0.3% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (5): Levofloxacin 1.5% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (6): Cefazolin 5% q30min to q1h on day 1 then q1h on day 2 then q4h on days 3-14 AND Tobramycin 5% ophthalmic ointment q1h on day 1 then q2h on day 2 then q4h on days 3-14

• 3.2 Streptococcus pneumoniae

• Preferred regimen (1): Moxifloxacin 0.5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (2): Gatifloxacin 0.3% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (3): Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14
• Preferred regimen (4): Ofloxacin 0.3% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (5): Levofloxacin 1.5% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (6): Cefazolin 5% q30min to q1h on day 1 then q1h on day 2 then q4h on days 3-14 AND Tobramycin 5% ophthalmic ointment q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Alternative regimen (unresponsive keratitis): Vancomycin 5% q30 min on day 1 then q2h on day 2 then q4h on days 3-14 AND Amikacin 5% q1h on day 1 then q2h on day 2 then q4h on days 3-14

• 3.3 Nocardia spp.

• Preferred regimen (1): Vancomycin 5% q30 min on day 1 then q2h on day 2 then q4h on days 3-14 AND Amikacin 5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (2): Erythromycin 0.5% ophthalmic ointment qhs for 1 week AND (Amikacin 5% AND/OR Vancomycin 5% q30 min on day 1 then q2h on day 2 then q4h on days 3-14)

• 3.4 Gram-negative bacteria

• Preferred regimen (1): Moxifloxacin 0.5% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (2): Gatifloxacin 0.3% q1h on day 1 then q2h on day 2 then q4h on days 3-14
• Preferred regimen (3): Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14
• Preferred regimen (4): Ofloxacin 0.3% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (5): Levofloxacin 1.5% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (6): Cefazolin 5% q30min to q1h on day 1 then q1h on day 2 then q4h on days 3-14 AND Tobramycin 5% ophthalmic ointment q1h on day 1 then q2h on day 2 then q4h on days 3-14

• 3.5 Anaerobes

• Preferred regimen (1): Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14
• Preferred regimen (2): Ofloxacin 0.3% ophthalmic ointment q2h for 2-3 weeks
• Preferred regimen (3): Levofloxacin 1.5% ophthalmic ointment q2h for 2-3 weeks

Fungal (mycotic) Keratitis

• 1. Causative Pathogens.

• Candida spp.
• Fusarium spp.
• Aspergillus spp.
• Curvularia spp.

• 2. Empiric antimicrobial therapy

• Preferred regimen (1): Natamycin 5% ophthalmic suspension q30min to q1h for 2-3 weeks
• Preferred regimen (2): Fluconazole 1% ophthalmic suspension q1h for 2-3 weeks
• Preferred regimen (3): Natamycin 5% ophthalmic suspension q30min to q1h for 2-3 weeks AND Fluconazole 1% ophthalmic suspension q1h for 2-3 weeks
• Alternative regimen (1), unresponsive: Amphotericin B 0.15-0.25% prepared in distilled water q15min-q30min on day 1-2 then q1h to q2h for 2-3 weeks
• Alternative regimen (2), unresponsive: Natamycin 5% ophthalmic suspension q30min to q1h for 2-3 weeks AND Amphotericin B 0.15-0.25% prepared in distilled water q15min-q30min on day 1-2 then q1h to q2h for 2-3 weeks

• 3. Special considerations

• Immunocompromised status, spreading ulcer, impending perforation, true perforation

• Preferred regimen (1): Natamycin 5% ophthalmic suspension q30min to q1h for 2-3 weeks AND Fluconazole 1% ophthalmic suspension q1h for 2-3 weeks AND (Ketoconazole IV 200-400 mg q12h for 2-3 weeks OR Fluconazole IV 200 mg q12h for 2-3 weeks
• Preferred regimen (2): Natamycin 5% ophthalmic suspension q30min to q1h for 2-3 weeks AND Amphotericin B 0.15-0.25% prepared in distilled water q15min-q30min on day 1-2 then q1h to q2h for 2-3 weeks AND (Ketoconazole IV 200-400 mg q12h for 2-3 weeks OR Fluconazole IV 200 mg q12h for 2-3 weeks
• Note: Bacterial superinfection must be treated using Ciprofloxacin 0.3% ophthalmic ointment q15min for 6 hours then q30min for the remainder of day 1 then q1h on day 2, then q4h on days 3-14 OR (Cefazolin 5% q30min to q1h on day 1 then q1h on day 2 then q4h on days 3-14 AND Tobramycin 5% ophthalmic ointment q1h on day 1 then q2h on day 2 then q4h on days 3-14)

Protozoal Keratitis

• 1. Causative pathogens

• Acanthamoeba spp.
• Microsporidia spp.

• 2. Empiric antimicrobial therapy

• Preferred regimen (1): Polyhexamethylene biguanide 0.02% ophthalmic ointment q1h for 1-2 weeks AND Chlorhexidine 0.02% ophthalmic ointment q1h for 1-2 weeks AND/OR (Propamidine 0.1% ophthalmic ointment q1h for 1-2 weeks OR Hexamidine 0.1% ophthalmic ointment q1h for 2 days then q1h for another 3 days)
• Preferred regimen (2): Propamidine 0.1% ophthalmic ointment q1h for 1-2 weeks AND Polyhexamethylene biguanide 0.02% ophthalmic ointment q1h for 1-2 weeks
• Preferred regimen (4): Propamidine ophthalmic ointment q1h for 1-2 weeks AND Chlorhexidine ophthalmic ointment q1h for 1-2 weeks
• Preferred regimen (4): Polyhexamethylene biguanide 0.02% ophthalmic ointment q1h for 1-2 weeks AND Hexamidine 0.1% ophthalmic ointment q1h for 2 days then q1h for another 3 days

Viral Keratitis

• 1. Causative pathogens

• Herpes simplex virus (HSV)

• 2. Empiric antimicrobial therapy

• Preferred regimen (1): Acyclovir 3% ophthalmic ointment q5h for 2-3 weeks AND Homatropine 2% ophthalmic solution bid for 2-3 weeks
• Preferred regimen (2): Idoxuridine 0.1% ophthalmic solution q1h in daytime and 0.5% ophthalmic ointment qhs for 1 week then 0.1% ophthalmic solution q2h in daytime and 0.5% ophthalmic ointment qhs for 2-3 weeks AND Homatropine 2% ophthalmic solution bid for 2-3 weeks

Contraindicated medications

Epithelial herpes simplex keratitis is considered an absolute contraindication to the use of the following medications:

• Fluorometholone
• Loteprednol
• Rimexolone
• Suprofen

Related Chapters

• List of eye diseases and disorders
• List of systemic diseases with ocular manifestations
• Thygeson's superficial punctate keratopathy
• Chronic superficial keratitis, or pannus, for the disease in dogs

External Links

• Facts About the Cornea and Corneal Disease The National Eye Institute (NEI)
• Filimentary keratitis

Template:WikiDoc Sources