Recommended Examination and Workup for Post-Surgical Ocular Infection
A thorough ocular examination with microbiological sampling must be performed immediately in patients with recent ocular surgical history and symptoms suggestive of infection to prevent vision loss and potentially devastating complications.
Initial Assessment
History
- Obtain detailed information about:
- Ocular symptoms (pain, redness, discharge, blurred vision, photophobia) and their duration 1
- Recent ocular surgical procedure (type, timing, complications)
- Contact lens history if applicable 1
- Previous ocular conditions (prior infections, dry eye, herpes simplex/zoster) 1
- Systemic medical conditions affecting immune status 1
- Current medications (topical and systemic) 1
- Medication allergies 1
Visual Acuity
- Measure and document baseline visual acuity with current correction 1
- Compare with pre-surgical visual acuity if available
External Examination
- Assess general appearance of the patient 1
- Evaluate eyelids and eyelid closure 1
- Note conjunctival injection and chemosis 1
- Examine nasolacrimal apparatus 1
Detailed Ocular Examination
Slit-Lamp Biomicroscopy
- Eyelids: inflammation, ulceration, abnormalities 1
- Conjunctiva: discharge, inflammation, morphologic alterations 1
- Cornea: epithelial defects, stromal infiltrates, edema, ulceration 1
- Anterior chamber: cell, flare, hypopyon, fibrin 1
- Iris: inflammation, surgical alterations 1
- Lens/IOL: position, inflammation 1
- Vitreous: cells, inflammation 1
Fluorescein Staining
- Apply to identify epithelial defects and assess wound integrity 1
- Differentiate epithelial staining from pooling in areas of corneal thinning 1
Intraocular Pressure
- Measure using applanation tonometry if safe (may defer if severe infection suspected) 1
Fundus Examination
- Examine posterior segment if media clarity permits 1
- Assess for vitreous cells, retinal involvement 1
Microbiological Workup
Corneal Cultures (for suspected bacterial keratitis)
- Obtain cultures before initiating antimicrobial therapy when possible
- Scrape the leading edge and base of the ulcer using a sterile blade
- Inoculate directly onto:
- Blood agar
- Chocolate agar
- Sabouraud agar
- Thioglycolate broth
- Slides for Gram stain and other stains as indicated
Anterior Chamber Tap (for suspected endophthalmitis)
- Collect aqueous sample using sterile technique
- Send for Gram stain and culture
Vitreous Tap/Biopsy (for suspected endophthalmitis)
- Obtain vitreous sample via pars plana approach
- Send for immediate Gram stain and culture
Additional Testing
Imaging
- B-scan ultrasonography if posterior segment cannot be visualized
- Consider CT scan if orbital involvement is suspected
Laboratory Tests
- Consider systemic workup if endogenous infection suspected:
- Complete blood count
- Blood cultures
- Inflammatory markers (ESR, CRP)
Common Pitfalls and Caveats
Delayed diagnosis: Post-surgical infections can progress rapidly; never delay examination and treatment of a suspected infection.
Inadequate sampling: Cultures should be obtained before initiating antimicrobial therapy whenever possible. Insufficient material may lead to false-negative results.
Misdiagnosis: Differentiate infectious from sterile inflammatory processes. Sterile inflammation typically appears earlier after surgery than infection.
Incomplete examination: Always examine the surgical wound carefully for leakage or dehiscence, which can be entry points for infection.
Overlooking contact lens history: Even in post-surgical patients, continued contact lens wear can be a risk factor for infection.
Failure to consider resistant organisms: Post-surgical infections may involve resistant pathogens, particularly MRSA or other multidrug-resistant organisms.
By following this systematic approach to examination and workup, you can rapidly diagnose and initiate appropriate treatment for post-surgical ocular infections, potentially saving the patient's vision and preventing devastating complications.