| disease | Bacterial Corneal Ulcer |
| alias | Bacterial Corneal Ulcer |
Bacterial corneal ulcer (bacterial corneal ulcer) is a suppurative infection of the cornea caused by pathogens such as Streptococcus pneumoniae, Staphylococcus, Pseudomonas aeruginosa, Neisseria gonorrhoeae, and Moraxella after the corneal epithelium is injured. In recent years, injuries from crops, fingernail scratches, iron filings, and contact lens abrasions have been the main causes. In rural areas, Streptococcus pneumoniae and Pseudomonas aeruginosa during the autumn and summer harvest seasons are the primary pathogens.
bubble_chart Clinical Manifestations
(1) Subjective symptoms
Significant photophobia, acute eye pain, visual impairment, eyelid spasm, tearing, and other irritative symptoms.
(2) Signs
1. Severe ciliary congestion: Abscess in the central part of the cornea, blurred structure, varying degrees of hypopyon in the anterior chamber, appearing yellow or light green.
2. Depending on the bacterial species, the formation of ulcers on the cornea varies: Pseudomonas aeruginosa ulcers are ring-shaped, with highly edematous surrounding cornea appearing ground-glass-like; serpiginous ulcers have gray-yellow progression with undermined edges, while the surrounding cornea remains transparent.
3. Serpiginous ulcers have gray-yellow pus adhering to the surface, while Pseudomonas aeruginosa ulcers have large amounts of yellow-green purulent discharge sticking to the surface.
4. Ulcers progressing deeper cause Descemet's membrane to bulge, and the ulcer may perforate within 2–5 days.
1. Based on clinical manifestations, combined with ulcer formation, reference to disease cause and medical history, a preliminary diagnosis can generally be made.
2. Scraping for bacterial staining and culture helps clarify the diagnosis.Table 12-4-1 Differential Diagnosis of Common Bacterial Corneal Ulcers
| Disease Cause | Clinical Features | Key Diagnostic Points |
| Staphylococcus | History of conjunctivitis, slow disease progression | Initial peripheral superficial ulcer, followed by central polymorphic ulcer, with minimal hypopyon |
| Streptococcus pneumoniae | Acute onset, possible history of corneal trauma, rapid ulcer progression | Central corneal ulcer with serpiginous, undermined advancing edge, grayish-yellow appearance, with hypopyon |
| Pseudomonas aeruginosa | History of trauma or foreign body, rapid ulcer progression, severe pain, marked irritation symptoms | Central ring-shaped ulcer, ground-glass corneal edema, yellowish-green pus on ulcer surface, abundant hypopyon, ulcer perforation within 2–3 days |
| Neisseria gonorrhoeae | Mostly seen in newborns | Conjunctival chemosis, peripheral corneal infiltration, epithelial breakdown spreading to central cornea, sometimes with hypopyon |
bubble_chart Treatment Measures
1. Frequently administer high-concentration, potent antibiotic eye drops every half hour, using sensitive drugs to prepare the eye drops or for subconjunctival injection. Systemic medication is generally not emphasized.
For Pseudomonas aeruginosa, eye drops containing 5u of polymyxin B per ml can be used every 15 to 30 minutes. Once secretions decrease and the condition stabilizes, the frequency of administration can be appropriately reduced. For severe cases, subconjunctival injection can be performed, with 170,000u per dose, once daily. Gentamicin can also be used, with subconjunctival injections of 40,000u per dose, once daily, and eye drop concentration at 1:4000.
For serpiginous ulcers, penicillin, gentamicin, or streptomycin can be selected.2. Appropriately combine debridement, mydriasis, and hot compresses.
3. If the condition cannot be controlled with medication and the ulcer is at risk of perforation, therapeutic lamellar keratoplasty may be considered. For severe cases with hypopyon, unhealthy vitreous, and a tendency toward endophthalmitis, enucleation should be considered.
