EYE (CONJUNCTIVA/CORNEAL SCRAPINGS/ORBITAL IMPLANTS/STYE/HORDEOLUM), CULTURE, AEROBIC BACTERIA
Test Code: EYES
To aid in the diagnosis of suspected bacterial conjunctivitis or other external eye infections.
Conjunctivitis can be infectious (viral or bacterial) or non-infectious (allergy). Because of the distinctive clinical presentation of both viral and bacterial conjunctivitis, and the self-limiting nature of these infections, a microbiological diagnosis is usually not necessary. Culture is indicated for patients with severe symptoms, immunocompromised state, with a vulnerable eye (e.g., after a corneal transplant), or poor response to initial therapy. Bacterial conjunctivitis is usually caused by Staphylococcus aureus, Streptococcus pneumonia, S. pyogenes and Haemophilus spp. Other causes include Neisseria gonorrhoeae, N. meningitides (newborn), and Chlamydia trachomatis.
Infection of the eyelids and lacrimal system (e.g., hordeolum [stye], blepharitis, canalicultitis, dacryoadenitis and dacryocystitis) are superficial infections that are generally self-limited, usually caused by Gram-positive bacteria. Clinical diagnosis may be supported by culture, though attributing a pathogenic role to organisms present may be difficult since these often represent normal skin flora. Anaerobic bacteria and fungi are rare causes of canaliculitis, whereas fungal species have occasionally been isolated in cases of dacryocystitis.
For other tests not performed by Shared Health (e.g., chlamydia, viral testing), please refer to the relevant laboratory that performs the testing.
Ocular swabs are evaluated by microscopy and culture (aerobic only). If clinically indicated, request for the detection of unusual or rare pathogens must be clearly stated on the requisition.
The diagnosis and the specific site of collection, e.g., left eye lid swab, must be indicated. Swabs must be taken prior to the application of topical anaesthetics.
Obtain specimen prior to initiation of antimicrobial therapy. If not possible, indicate antimicrobial therapy on ordering requisition.
For clinical suspicion of preseptal and orbital cellulitis, blood cultures are recommended in addition to the culture of open wounds. In addition, sinus aspirate may be submitted for culture in the context of orbital cellulitis. Ocular cultures often fail to yield the infecting organism.
Samples and requisitions must be labeled/completed in accordance with the Shared Health Specimen Acceptance Policy.
Accurate patient identification must be made prior to sample collection. Patient identification should be done in accordance with the site policy.
Patient Preparation Instructions:
1. Sample eye using swab pre-moistened with sterile saline.
2. Roll swab over conjunctiva.
3. Transport immediately to the laboratory.
1 - eSwab - Specimens received in other collection devices will not be processed.
|Specimen Required:||Conjunctival swab, Eye socket swab, Eye lid swab, Stye/hordeolum swab, Lacrimal/sac swab (Adult and Pediatric)|
No organisms isolated after 48 hours (aerobic culture).
For positive specimens, a descriptive report will be provided.
FUNGI, CULTURE, ALL SPECIMEN TYPES EXCLUDING BLOOD (E.G., CORNEAL SCRAPINGS/FLUID/TISSUE/BONE MARROW/GASTRIC WASHINGS)
Specimens must be delivered to the laboratory as soon as possible.
Do not refrigerate eye specimens.
Local: ≤2 hrs, hold at room temperature.
Courier/local storage: ≤24 hrs, hold at room temperature.
Ensure samples that are being sent to a referral laboratory are packaged in accordance with Transport of Dangerous Goods recommendations for diagnostic samples.