Endophthalmitis

Overview

Endophthalmitis is a severe, sight-threatening infection that affects the interior of the eye, specifically involving the vitreous cavity and sometimes the anterior chamber. This condition represents an ophthalmologic emergency that requires immediate diagnosis and treatment to preserve vision. The infection causes inflammation of the intraocular fluids and tissues, leading to rapid destruction of retinal architecture and potentially irreversible vision loss if not treated promptly. Despite advances in treatment, endophthalmitis remains one of the most devastating complications in ophthalmology, with visual outcomes often being poor even with aggressive intervention.

The condition can be classified into two main categories: exogenous (from external sources) and endogenous (from internal sources). Exogenous endophthalmitis, which accounts for the majority of cases, typically occurs following eye surgery, penetrating eye trauma, or extension from corneal infections. Post-operative endophthalmitis is the most common form, occurring in approximately 0.05-0.3% of cataract surgeries, though the incidence varies with the type of procedure. Endogenous endophthalmitis, though less common (2-8% of cases), results from hematogenous spread of organisms from distant infection sites and often indicates serious systemic illness.

The pathophysiology of endophthalmitis involves rapid bacterial or fungal multiplication within the normally sterile intraocular environment, triggering an intense inflammatory response. This inflammation, while aimed at controlling infection, paradoxically contributes to retinal damage through the release of inflammatory mediators, toxins, and enzymes. The unique anatomy of the eye, with its blood-ocular barriers and lack of lymphatic drainage, makes it particularly vulnerable to infection while also limiting the penetration of systemic antibiotics. The prognosis depends on multiple factors including the virulence of the causative organism, the time to treatment initiation, and the patient's immune status, with some cases resulting in complete vision loss despite optimal treatment.

Symptoms

The symptoms of endophthalmitis typically develop rapidly and progressively worsen without treatment. The presentation can vary depending on the causative organism and route of infection.

Primary Ocular Symptoms

Additional Eye Symptoms

• Hypopyon (pus in anterior chamber)
• Vitreal haze or opacity
• Photophobia (light sensitivity)
• Excessive tearing
• Eye irritation and foreign body sensation
• Discharge from the eye
• Floaters or flashes of light

Clinical Signs (Observable by Physician)

• Corneal edema and haziness
• Fibrin in anterior chamber
• Posterior synechiae
• Absent red reflex
• Vitreous cells and debris
• Retinal infiltrates or abscesses
• Chemosis (conjunctival swelling)

Systemic Symptoms

Particularly in endogenous cases:

• Fever and chills
• General malaise
• Signs of systemic infection
• Urinary symptoms (if urinary tract infection source)
• Headache
• Nausea

Time Course of Symptoms

Acute Post-operative (Days to 1 week)

• Rapid onset after surgery
• Severe pain and vision loss
• Marked inflammation
• Usually bacterial cause

Delayed Post-operative (Weeks to months)

• Gradual onset
• Less severe pain
• Chronic inflammation
• Often low-virulence organisms

Post-traumatic (Hours to days)

• Very rapid progression
• May have retained foreign body
• Associated with wound abnormalities

Severity Indicators

• Pain out of proportion to findings
• Rapid visual deterioration
• Dense vitreal opacification
• Large hypopyon
• Corneal infiltration
• Proptosis (eye bulging)

Causes

Endophthalmitis can result from various sources of infection, with different organisms predominating based on the route of infection.

Exogenous Endophthalmitis

Post-operative Causes

• Cataract surgery: Most common surgical cause
• Intravitreal injections: Anti-VEGF therapy, steroids
• Glaucoma surgery: Filtering blebs
• Vitrectomy: Pars plana procedures
• Keratoplasty: Corneal transplantation
• Refractive surgery: LASIK complications (rare)

Post-traumatic Causes

• Penetrating eye injuries
• Intraocular foreign bodies
• Rupture globe injuries
• Contaminated wounds
• Delayed wound closure

Keratitis-related

• Corneal ulcer perforation
• Fungal keratitis extension
• Contact lens-related infections
• Herpetic keratitis complications

Endogenous Endophthalmitis

Systemic Sources

• Bacteremia/Septicemia: From any source
• Endocarditis: Bacterial vegetation
• Urinary tract infections: Especially in diabetics
• Skin/soft tissue infections: Cellulitis, abscesses
• Gastrointestinal sources: Liver abscesses
• Meningitis: CNS infections

Common Causative Organisms

Bacterial

• Gram-positive:
  • Staphylococcus epidermidis (most common post-op)
  • Staphylococcus aureus
  • Streptococcus species
  • Enterococcus species
  • Propionibacterium acnes (chronic)
• Gram-negative:
  • Pseudomonas aeruginosa
  • Klebsiella species
  • Escherichia coli
  • Serratia marcescens

Fungal

• Candida species (most common fungal)
• Aspergillus species
• Fusarium species
• Cryptococcus (in immunocompromised)

Risk Factors for Infection

Surgical Factors

• Complicated surgery
• Prolonged surgical time
• Posterior capsule rupture
• Vitreous loss
• Wound leak
• Contaminated instruments

Patient Factors

• Diabetes mellitus
• Immunosuppression
• Chronic blepharitis
• Nasolacrimal duct obstruction
• Contact lens wear
• Active systemic infection

Risk Factors

Multiple factors can increase the risk of developing endophthalmitis:

Surgical Risk Factors

• Type of surgery: Complex procedures higher risk
• Clear corneal incisions: Without sutures
• Secondary IOL implantation: Increased manipulation
• Combined procedures: Multiple surgeries
• Reoperation: Within short time frame
• Surgeon experience: Learning curve factors

Patient-Related Factors

• Advanced age (>85 years)
• Male gender (slight increase)
• Diabetes mellitus
• Immunocompromised state
• Chronic ocular surface disease
• Previous ocular surgery
• Rural residence (delayed access to care)

Ocular Conditions

• Blepharitis or meibomian gland dysfunction
• Conjunctivitis
• Lacrimal system infection
• Corneal disease
• Eyelid abnormalities
• Dry eye syndrome

Systemic Conditions

• Active systemic infection
• Intravenous drug use
• Chronic renal failure
• Liver disease
• Malignancy
• HIV/AIDS
• Organ transplantation

Environmental Factors

• Contaminated surgical equipment
• Break in sterile technique
• Contaminated eye drops
• Poor operating room ventilation
• Outbreak situations

Trauma-Related Risks

• Dirty wound contamination
• Retained foreign body
• Delayed presentation
• Agricultural injuries
• Soil contamination
• Inadequate initial treatment

Diagnosis

Rapid and accurate diagnosis of endophthalmitis is crucial for preserving vision. Clinical suspicion based on symptoms and signs must be confirmed with appropriate testing.

Clinical Examination

Essential Components

• Visual acuity: Often severely reduced
• Slit lamp examination: Anterior segment evaluation
• Intraocular pressure: May be elevated or reduced
• Pupillary reactions: Often sluggish
• Fundoscopy: If media permits

Key Clinical Findings

• Lid edema and erythema
• Conjunctival injection and chemosis
• Corneal edema
• Anterior chamber cells and flare
• Hypopyon (layered pus)
• Fibrin formation
• Vitreal haze or opacity
• Absent or poor red reflex

Diagnostic Procedures

Vitreous Sampling

• Vitreous tap: Needle aspiration (0.1-0.2 mL)
• Vitreous biopsy: During vitrectomy
• Performed before antibiotic injection
• Sent for culture and sensitivity
• Gram stain for immediate information

Anterior Chamber Tap

• Aqueous humor sampling
• May be less diagnostic than vitreous
• Easier to perform
• Used when vitreous tap not possible

Laboratory Testing

Microbiological Studies

• Gram stain: Immediate results
• Bacterial cultures: Blood and chocolate agar
• Fungal cultures: Sabouraud dextrose agar
• Antibiotic sensitivity testing: Guide therapy
• PCR testing: For culture-negative cases

Systemic Workup (Endogenous)

• Blood cultures
• Urine culture
• Chest X-ray
• Echocardiography (if endocarditis suspected)
• Abdominal imaging

Imaging Studies

B-scan Ultrasonography

• Assess posterior segment when view obscured
• Detect vitreous opacities
• Rule out retinal detachment
• Identify foreign bodies
• Monitor treatment response

Optical Coherence Tomography (OCT)

• If media clarity permits
• Assess macular involvement
• Monitor structural changes
• Document treatment response

Differential Diagnosis

• Toxic anterior segment syndrome (TASS): Sterile inflammation
• Retained lens material: Post-surgery
• Severe uveitis: Non-infectious
• Sympathetic ophthalmia: Bilateral granulomatous
• Phacoanaphylactic uveitis: Lens protein reaction
• Malignancy: Masquerade syndrome

Diagnostic Challenges

• Culture-negative cases (25-50%)
• Prior antibiotic use
• Fastidious organisms
• Small sample volumes
• Delayed presentation
• Chronic low-grade infections

Treatment Options

Endophthalmitis requires immediate and aggressive treatment. The approach combines intravitreal antibiotics, possible surgical intervention, and supportive care.

Emergency Management

Immediate Actions

• Urgent ophthalmology consultation
• Pain management
• Dilating drops (cycloplegia)
• Avoid any delays in treatment
• NPO if surgery anticipated

Intravitreal Antibiotics

Standard Empiric Therapy

• Vancomycin: 1mg/0.1mL (gram-positive coverage)
• Ceftazidime: 2.25mg/0.1mL (gram-negative coverage)
• Alternative: Amikacin 0.4mg/0.1mL
• Given immediately after vitreous tap
• May require repeat injections

Antifungal Therapy

• Amphotericin B: 5-10μg/0.1mL
• Voriconazole: 100μg/0.1mL
• Used when fungal infection suspected
• Consider in delayed onset cases

Surgical Treatment

Pars Plana Vitrectomy

Indications:

• Visual acuity light perception or worse
• Severe vitritis obscuring view
• No improvement after initial treatment
• Retained lens material
• Foreign body removal needed

Benefits:

• Removes infected vitreous
• Reduces bacterial/toxin load
• Better antibiotic distribution
• Allows retinal evaluation
• Obtains better specimens

Systemic Treatment

Systemic Antibiotics

• Limited penetration into vitreous
• Used as adjunct therapy
• Essential for endogenous cases
• Based on culture results when available
• IV administration preferred initially

Corticosteroids

• Intravitreal: Dexamethasone 0.4mg/0.1mL
• Systemic: Oral prednisone
• Controversial timing
• May reduce inflammation
• Avoid in fungal infections

Topical Therapy

• Fortified antibiotics: Vancomycin, tobramycin
• Corticosteroids: After infection control
• Cycloplegics: Atropine, cyclopentolate
• IOP-lowering drugs: If elevated pressure

Treatment Monitoring

• Daily evaluation initially
• Visual acuity assessment
• Clinical response to treatment
• B-scan if no view
• Repeat cultures if no improvement
• Consider repeat intravitreal injection

Specific Organism Treatment

Streptococcus

• Often aggressive course
• Early vitrectomy beneficial
• Good vancomycin sensitivity

Propionibacterium acnes

• Chronic presentation
• May require IOL removal
• Capsular bag removal
• Prolonged treatment course

Fungal

• Poor prognosis
• Vitrectomy often required
• Prolonged antifungal therapy
• Consider oral voriconazole

Complications Management

• Retinal detachment: Surgical repair
• Hypotony: Temporary or permanent
• Phthisis bulbi: End-stage disease
• Sympathetic ophthalmia: Monitor fellow eye
• Enucleation: Blind painful eye

Prevention

Prevention of endophthalmitis focuses on minimizing infection risk during procedures and managing predisposing factors.

Surgical Prevention

Preoperative Measures

• Povidone-iodine 5%: Conjunctival sac irrigation
• Treat blepharitis before surgery
• Lid hygiene optimization
• Prophylactic topical antibiotics (controversial)
• Draping of lashes and lid margins
• Minimize talking during surgery

Intraoperative Techniques

• Proper wound construction
• Maintain closed system
• Minimize surgical time
• Careful tissue handling
• Sterile technique maintenance
• Intracameral antibiotics (cefuroxime)

Postoperative Care

• Topical antibiotic drops
• Patient education on hygiene
• Avoid eye rubbing
• Prompt follow-up
• Early detection of complications

Injection Technique

• Povidone-iodine preparation
• Sterile lid speculum use
• Avoid needle contact with lashes
• Post-injection antibiotics
• Monitor for complications

Trauma Prevention

• Protective eyewear use
• Workplace safety measures
• Sports eye protection
• Prompt treatment of injuries
• Prophylactic antibiotics for high-risk wounds

Managing Risk Factors

• Optimize diabetes control
• Treat ocular surface disease
• Address immunosuppression
• Manage systemic infections
• Regular eye examinations

Environmental Controls

• Operating room air quality
• Instrument sterilization protocols
• Single-use items when possible
• Proper storage of medications
• Regular equipment maintenance

Patient Education

• Recognize warning symptoms
• Importance of follow-up
• Proper drop instillation
• Hand hygiene
• When to seek urgent care

When to See a Doctor

Endophthalmitis is an ophthalmic emergency requiring immediate medical attention. Any delay can result in permanent vision loss.

Seek IMMEDIATE Emergency Care

• Severe eye pain, especially after eye surgery or injury
• Rapid vision loss or sudden blindness
• Eye pain with decreased vision
• Pus or discharge from recent surgical site
• Severe light sensitivity with eye pain
• Eye swelling with fever
• Any concerning symptoms after eye injection

Post-Surgical Warning Signs

After any eye surgery, immediately report:

• Increasing pain instead of improving
• Vision getting worse, not better
• New floaters or flashes
• Increasing redness
• Any discharge from eye
• Swelling around eye
• Nausea or vomiting with eye symptoms

High-Risk Situations

• Recent cataract surgery (within 6 weeks)
• Recent intravitreal injection
• Eye trauma with open wound
• Foreign body in eye
• Severe eye infection not improving
• Systemic infection with eye symptoms

Do NOT Delay

• Do not wait for morning if symptoms at night
• Do not assume it will improve
• Do not try home remedies
• Do not delay even if recently seen
• Better to be evaluated unnecessarily than lose vision

What to Tell Emergency Staff

• Recent eye surgery or procedure
• Time since surgery/injury
• Current symptoms and progression
• Medications being used
• Any systemic illness
• Previous eye conditions

Follow-up Care

After treatment, maintain close follow-up:

• Daily visits initially
• Strict compliance with medications
• Report any worsening immediately
• Long-term monitoring for complications
• Vision rehabilitation if needed

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Frequently Asked Questions