Diagnosis of Eye Infections
The diagnosis of eye infections typically begins with a clinical examination by an eye care professional. Because eye infections vary widely in severity and cause, it is important to correctly identify the underlying issue to provide effective treatment and prevent complications.
Medical History and Symptom Review
Doctors begin by asking detailed questions about:
When the symptoms started
What kind of discharge is present (watery, thick, coloured)
Whether one or both eyes are affected
Any recent illness, like a cold or sore throat
Use of contact lenses or recent eye injury
History of travel or exposure to contaminated water
These questions help narrow down whether the infection is bacterial, viral, fungal, or parasitic.
Eye Examination
A visual inspection is the first step. Doctors use tools like:
Slit lamp microscope – Allows a close-up view of the cornea, iris, and conjunctiva
Ophthalmoscope – To assess the retina and optic nerve if infection may involve the inner eye
Fluorescein dye test – Highlights damage to the cornea and identifies ulcers or abrasions
Swelling, redness, corneal haze, or discharge help determine the likely cause and site of infection.
Swabs and Cultures
For persistent or severe cases, a sample of eye discharge may be collected:
Bacterial cultures – Help determine the exact strain and antibiotic sensitivity
Viral PCR testing – Detects specific viruses such as adenovirus or herpes
Fungal or parasitic tests, where suspected, are more specialised and may take longer
Swabs are especially useful if the infection doesn’t respond to first-line treatments or recurs frequently.
Additional Investigations
If the infection is severe or vision-threatening:
Ultrasound of the eye may be done if visibility is limited by swelling or opacities
Blood tests could be ordered if a systemic infection or immune deficiency is suspected
Imaging such as CT or MRI may be used in rare cases when orbital cellulitis or internal spread is a concern
Contact Lens Users
If a contact lens-related infection is suspected, the lenses and storage case may also be tested to identify contamination.
Importance of Timely Diagnosis of Eye Infections
Early and accurate diagnosis ensures targeted treatment. Misdiagnosing a viral infection as bacterial (or vice versa) can lead to ineffective therapy, prolonged symptoms, or worse outcomes.
The diagnosis of eye infections is usually straightforward but may require specialised tools or lab tests in more complex cases. Prompt evaluation protects vision and speeds recovery.
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