Endophthalmitis

The primary cause of endophthalmitis is the introduction of microorganisms into the internal chambers of the eye. Research published in Ophthalmology (2023) indicates that Gram-positive bacteria, such as Staphylococcus epidermidis and Staphylococcus aureus, are responsible for the majority of post-operative cases. These bacteria often reside on the patient's own skin or eyelids and gain entry during a surgical incision. Pathophysiologically, once these organisms enter the nutrient-rich vitreous, they multiply rapidly, releasing toxins that trigger a massive immune response, leading to tissue necrosis (cell death).

Non-Modifiable Risk Factors

• Age: Older adults are at higher risk due to the higher frequency of cataract surgeries.
• Immune Status: Individuals with compromised immune systems (e.g., due to HIV/AIDS or organ transplant) are more susceptible to endogenous infections.
• Gender: Some studies suggest a slightly higher incidence in males, often linked to a higher rate of ocular trauma.

Modifiable Risk Factors

• Diabetes Management: Poorly controlled blood sugar can impair the immune response and increase the risk of infection after surgery.
• Eyelid Health: Chronic blepharitis (eyelid inflammation) increases the bacterial load near the eye.
• Intravenous Drug Use: A significant risk factor for endogenous endophthalmitis, as bacteria or fungi can be introduced directly into the bloodstream.
• Contact Lens Hygiene: While rare, severe corneal ulcers from poor contact lens care can occasionally penetrate the eye and cause endophthalmitis.

According to the Centers for Disease Control and Prevention (CDC, 2024), patients undergoing intraocular procedures, such as cataract surgery or intravitreal injections for macular degeneration, are in the highest risk category. Additionally, individuals who sustain penetrating eye injuries (e.g., from metallic fragments or organic matter like wood) have a 10% to 30% risk of developing the condition if not treated prophylactically.

Prevention focuses on strict sterile techniques during surgery. The use of povidone-iodine on the ocular surface before surgery is the gold standard for reducing bacterial load. Research suggests that intracameral (into the eye) antibiotic injections at the end of cataract surgery can reduce the risk of endophthalmitis by up to 80% (ASCRS, 2023). Patients are also advised to use prescribed antibiotic drops exactly as directed before and after procedures.

The diagnostic journey begins with a rapid clinical assessment. Because time is critical, ophthalmologists often begin treatment based on clinical suspicion before laboratory results are finalized.

A comprehensive eye exam is performed, including a slit-lamp examination to look for signs of inflammation in the anterior chamber and vitreous. The doctor will check intraocular pressure and assess the patient's ability to see light, shapes, or letters.

• Vitreous Tap and Biopsy: This is the definitive diagnostic tool. A small needle is used to remove a sample of the vitreous fluid, which is then sent for Gram staining, cultures, and PCR (Polymerase Chain Reaction) testing to identify the specific pathogen.
• B-scan Ultrasonography: If the interior of the eye is too cloudy for the doctor to see the retina, an ultrasound is used to check for retinal detachment or dense inflammatory debris in the vitreous.
• Blood Cultures: Performed if endogenous endophthalmitis is suspected to identify the primary source of infection in the body.

Diagnosis is typically based on the presence of 'vitritis' (inflammation of the vitreous) in a patient with a recent history of surgery, trauma, or systemic infection. A positive culture from the vitreous fluid confirms the diagnosis, though 'culture-negative' cases occur in about 30% of clinical endophthalmitis presentations.

Healthcare providers must rule out other conditions, such as:

• TASS (Toxic Anterior Segment Syndrome): A non-infectious inflammatory reaction to surgical instruments or medications.
• Severe Uveitis: Autoimmune inflammation of the eye.
• Intraocular Lymphoma: A type of cancer that can mimic the appearance of infection.
• Retinal Detachment: Which can cause sudden vision loss but typically lacks the intense pain and redness of endophthalmitis.

The primary goals of treatment are to eliminate the infecting organism, control the inflammatory response to prevent tissue damage, and preserve as much vision as possible. Successful treatment is measured by the clearing of the vitreous and the stabilization or improvement of visual acuity.

Per the Endophthalmitis Vitrectomy Study (EVS) guidelines and updated clinical protocols, the standard initial approach involves the immediate injection of broad-spectrum antibiotics directly into the eye (intravitreal injection). This bypasses the blood-ocular barrier, delivering high concentrations of medication where they are needed most. Talk to your healthcare provider about which approach is right for you.

• Glycopeptide Antibiotics: Often the first choice for Gram-positive coverage. They work by inhibiting bacterial cell wall synthesis. These are typically administered via intravitreal injection.
• Cephalosporin Antibiotics: Used to provide broad coverage against Gram-negative bacteria. They also interfere with bacterial cell wall integrity.
• Fluoroquinolone Antibiotics: These may be used as supplemental oral or topical therapy. They work by inhibiting bacterial DNA enzymes, preventing replication.
• Corticosteroids: Once the infection is being addressed by antibiotics, corticosteroids are often used (either via injection or drops) to dampen the immune response and reduce swelling. Common side effects include increased eye pressure.
• Antifungals: Reserved for cases where a fungal pathogen is suspected or confirmed. These work by disrupting the fungal cell membrane.

If the initial injection does not result in improvement within 24–48 hours, a second injection of a different antibiotic class may be administered. In some cases, oral antibiotics with high ocular penetration may be added to the regimen.

• Pars Plana Vitrectomy (PPV): This is a surgical procedure where the infected vitreous gel is physically removed and replaced with a sterile saline solution or silicone oil. This helps remove the bulk of the bacteria and inflammatory toxins. According to clinical guidelines, vitrectomy is often prioritized for patients with very poor initial vision (light perception only).

Patients are typically monitored daily for the first few days. Topical antibiotic and steroid drops may continue for several weeks. Long-term monitoring is essential to watch for complications like secondary glaucoma or retinal scarring.

• Pregnancy: Intravitreal injections are generally preferred over systemic medications to minimize fetal exposure, though the choice of antibiotic must be carefully weighed.
• Elderly: Dose adjustments for systemic medications may be necessary if kidney function is impaired, but intravitreal doses remain standard.

> Important: Talk to your healthcare provider about which approach is right for you.

While diet cannot cure endophthalmitis, supporting the immune system is vital during recovery. Research suggests that a diet rich in antioxidants (Vitamins C, E, and Zinc) can support retinal health. The Age-Related Eye Disease Study (AREDS2, 2023) highlights the importance of lutein and zeaxanthin for protecting ocular tissues from oxidative stress during inflammation.

During the acute recovery phase (usually 2-4 weeks), patients should avoid strenuous exercise, heavy lifting, or bending over, as these activities can increase intraocular pressure and strain surgical incisions. Walking is generally encouraged as soon as the patient feels stable.

Proper rest is crucial for tissue repair. Patients are often advised to sleep with their head slightly elevated (using two pillows) to help reduce ocular swelling. Using a protective eye shield at night is mandatory to prevent accidental rubbing or pressure on the eye.

Vision loss is highly stressful. Evidence-based techniques such as mindfulness-based stress reduction (MBSR) or diaphragmatic breathing can help manage the anxiety associated with frequent procedures and uncertain visual outcomes.

There is no evidence that herbal remedies or acupuncture can treat endophthalmitis. These should never replace conventional medical care. However, some patients find that omega-3 fatty acid supplements help manage dry eye symptoms that often occur after ocular surgery.

• Medication Management: Help the patient keep a strict schedule for eye drops, which may be required every 1-2 hours initially.
• Safety: Remove tripping hazards from the home, as the patient’s depth perception will be severely compromised while one eye is patched or healing.
• Transportation: Ensure the patient has reliable transport to daily or weekly follow-up appointments.

The prognosis for endophthalmitis varies significantly based on the causative organism and the speed of treatment. According to a study in The Lancet (2023), approximately 50% of patients with post-operative endophthalmitis achieve a final visual acuity of 20/40 or better if treated promptly. However, infections caused by virulent organisms like Pseudomonas or Bacillus cereus often have a much poorer prognosis, sometimes resulting in total blindness or the need for eye removal (enucleation).

• Retinal Detachment: The inflammation can cause the retina to pull away from the back of the eye.
• Secondary Glaucoma: Inflammatory debris can block the eye's drainage system, leading to high pressure.
• Phthisis Bulbi: A condition where the eye shrivels and loses function due to severe damage.
• Corneal Scarring: Permanent clouding of the front of the eye.

Ongoing monitoring by a retina specialist is required for at least 6-12 months. This includes regular checks of intraocular pressure and retinal integrity. Relapse is rare but can occur if the initial infection was not fully eradicated.

If permanent vision loss occurs, low-vision rehabilitation can help patients maximize their remaining sight using magnifiers, high-contrast tools, and adaptive technology. Support groups for the visually impaired provide essential emotional and practical resources.

Contact your ophthalmologist immediately if you notice a sudden increase in floaters, flashes of light, a 'curtain' over your vision, or a return of eye pain after the initial recovery period.