Keratitis

Disease Description (Causes and Symptoms)

• Definition: A condition in which the cornea (the transparent front tissue of the eye) becomes inflamed, ranging from mild superficial inflammation to corneal ulceration (involving the stroma) and perforation.
• Main causes
  • Infectious: Bacteria (e.g., Staphylococcus, Pseudomonas — high risk in contact lens-related cases), viruses (e.g., herpes simplex virus [HSV]), fungi (e.g., Fusarium, Aspergillus), etc.
  • Noninfectious: Improper contact lens use, trauma, exposure to medications or chemicals, exposure keratitis (inadequate eyelid closure), neurotrophic keratitis (loss of corneal sensation), autoimmune diseases, etc.
• Pathophysiology: Pathogens or injury cause inflammation and cellular damage in the corneal epithelium and stroma; in severe cases, this can progress to ulceration, stromal opacity, neovascularization, perforation, and intraocular infection (endophthalmitis).
• Main symptoms: Eye pain or stinging, foreign-body sensation, tearing, redness (conjunctival injection), photophobia (light sensitivity), decreased vision, and blurred vision. Emergency evaluation is needed if there is acute, progressive pain or worsening vision.

Treatment Methods (Standard Treatment · Precautions · Lifestyle Management)

• General principles
  • Rapidly differentiate whether the condition is infectious and begin antibacterial, antiviral, or antifungal treatment according to the cause.
  • If bacterial keratitis is suspected, begin immediate topical antibiotic treatment (under the direction of an ophthalmologist); in severe cases, hospitalization and intensive eye-drop treatment may be required.
  • If fungal keratitis is suspected, use antifungal eye drops (e.g., natamycin is recommended as an empiric first-line treatment) and undergo long-term treatment.
  • Viral (HSV) keratitis: For superficial epithelial lesions, use topical antivirals (e.g., trifluridine, ganciclovir gel, etc.); for stromal or recurrent lesions, oral acyclovir may be considered in combination.
• Medication treatment (follow the doctor's prescription)
  • Topical antibiotics: Use broad-spectrum fluoroquinolones or fortified antibiotics according to the causative pathogen.
  • Antifungals: Topical natamycin or voriconazole; systemic antifungals may be used in combination when necessary.
  • Antivirals: Topical antivirals and, depending on the severity of the disease, oral antivirals.
  • Anti-inflammatory treatment (steroids): Use only after the infection is controlled and strictly according to an ophthalmologist's instructions. (Steroids can worsen the disease when it is infectious.)
• Nonmedication and surgical treatment
  • Artificial tears, eye ointment, and therapeutic contact lenses (for pain relief and promotion of epithelial healing), as well as eye protection (eye patch).
  • In cases of severe ulceration, perforation, or significant opacity affecting vision, therapeutic keratoplasty (emergency, lamellar, or penetrating keratoplasty) may be considered.
  • Conjunctival flap transplantation, collagen (AM) transplantation, suturing, and other suture procedures may be performed when necessary.
• Lifestyle management and precautions
  • Stop wearing contact lenses immediately (do not continue wearing them based on your own judgment); bring the lenses and case to the examination.
  • Do not self-treat (including using nonprescription steroid eye drops).
  • Immediate emergency care is needed if pain or vision worsens during treatment, purulent discharge occurs, or severe photophobia increases.
  • Patients with diabetes, immunosuppression, or a history of ophthalmic surgery have an increased risk of complications — prompt evaluation is recommended.

Pre-Outpatient Visit Checklist (What to Bring · Useful Information for the Visit)

• What to bring
  • A list of currently used medications (including eye drops) and a history of allergies (including medication and eye-drop allergies).
  • If you use contact lenses: The lenses, lens case, the time of last use, and wearing habits (such as whether they are worn while sleeping).
  • Recent ophthalmic examination results, if available, and records of previous ophthalmic surgery or eye trauma.
  • The time symptoms began and their course (when they started, factors that worsen or improve them), and photographs (if possible, take photos in advance with a smartphone).
  • Systemic diseases (diabetes, immunosuppressive treatment, steroid use, etc.).
• Things to do before the visit
  • If symptoms are severe, go immediately to an emergency room or ophthalmology clinic.
  • When making an outpatient appointment, inform the clinic in advance about the acuity of the symptoms (whether there is severe pain or decreased vision).
• Example of an explanation to give the doctor
  • “When did the symptoms begin recently, and how have they progressed?”
  • “Do you use contact lenses, and what are your wearing habits (such as wearing them at night)?”

Examples of General Questions to Ask the Doctor

• What are the main side effects of this medication (eye drops/oral medication)? What should I do if side effects occur?
• How long is the expected treatment period, and what is the expected degree of vision recovery?
• When can I resume daily activities (driving, working, and wearing contact lenses)?
• Are there any measures I should take to prevent recurrence?
• Which medications, eye drops, or activities should I avoid during treatment (e.g., prohibiting steroid eye drops)?

Examples of Disease-Specific Questions

• Patients suspected of having a contact lens-related condition:
  • “Do I need to stop wearing contact lenses right now? Should I bring the lenses and case to the examination?”
• Patients suspected of or diagnosed with herpes (HSV):
  • “Do I need to take long-term (preventive) antiviral medication to prevent recurrence? If so, for how long?”

(When necessary, prescriptions, examinations, and whether emergency care is needed will be determined based on the diagnosis of an ophthalmology specialist.)