Management of Endophthalmitis

Abstract

Infectious endophthalmitis is initially a clinical diagnosis made on the constellation of signs and symptoms discussed before. The commonest test beyond clinical examination by slit lamp and indirect ophthalmoscopy is the ultrasonography.

Frequently Asked Questions

• 1. I had an endophthalmitis which was appropriately managed. Now the media is completely clear, and optic disk does not show gross pallor, but the vision is still very poor on final refraction. What to do?

  A: Assess the fovea on slit lamp biomicroscopy and with an optical coherence tomography. Most such cases which do not improve optimally have a chronic cystoid macular edema. An accompanying fundus fluorescein angiography to assess macular perfusion adds to the information. In an ischemic macular edema, the guarded visual prognosis should be explained. In case the macula is well perfused, intravitreal anti-VEGF or steroids can be attempted with due discussion with the patient about the pros and cons.

• 2. Is there a way to suspect microorganism-specific infection?

  A: There is no foolproof clinical examination modality to identify a specific microorganism in endophthalmitis. Certain clinical features and demographics may suggest a particular organism. Acute post-cataract surgery endophthalmitis is usually caused by coagulase-negative staphylococci. In post-surgical cases following corneal tissue transplants or fulminant host corneal infiltrates, a gram-negative etiology is suspected. Associated nasolacrimal duct blockade often suggests infection with pneumococci. Bacillus species especially Bacillus cereus is a common etiology following open-globe injuries. In a filtering bleb-associated endophthalmitis, the etiology of acute endophthalmitis is coagulase-negative staphylococci, whereas in a delayed presentation, Streptococcus spp. and Haemophilus influenzae are commonly seen. Organisms commonly seen in chronic low-grade endophthalmitis include coagulase-negative staphylococci, Propionibacterium, and fungi. Fungus species especially Candida are the commonest isolates seen in endogenous endophthalmitis especially in immunocompromised and systemically ill patients.

• 3. How long should one wait for a second intervention?

  A: The second intervention is guided by the half-life of the antibiotics injected at the first intervention. The most commonly used empirical antibiotics have a vitreous half-life of about 48 h. Hence a repeat intervention is merited at 48 h. For intravitreal voriconazole, as the half-life is lesser, a repeat intervention is required every 24 h.

• 4. What do we infer when the injected antibiotics are not sensitive to the identified microorganism, but the patient is doing well clinically?

  A: The laboratory reports in endophthalmitis management are a guideline to initiate treatment. The final decision of the treatment is based on the clinical impression. Occasionally, it’s possible that the culture plate has picked up a contaminant preferentially which outgrows the actual organism from the biopsy sample. This could also indicate that the organism from the sample is not virulent. The culture sensitivity report in this case may reflect that of the contaminant and not of the one in the sample. Alternately, there could be the same organism with multiple strains of resistance patterns in the same infection. The culture may have grown the resistant ones preferentially, while the vitreous may be harboring the sensitive ones. So continuation of the same treatment is warranted.

• 5. What do we infer when the injected antibiotics are sensitive to the identified microorganism, but the patient is not doing well clinically?

  A: Similar to the previous situation, a possibility of a contaminant should be kept in mind. This situation would warrant a repeat vitreous sampling preferably along with the cassette fluid. One may also consider changing the laboratory to get a correct yield of organisms. In spite of the above if no suitable culture sensitivity patterns are obtained, change the empirical antibiotic combination. One can consider also taking an expert second opinion and a possibility of a noninfectious masquerade.

• 6. How do I approach a patient for the fellow eye intraocular surgery where the other eye was successfully treated for culture-positive endophthalmitis?

  A: Revisit the history and postinfection surveillance report to identify causative factors if any for the previous endophthalmitis. Take adequate precautions to ensure all protocols are adhered to and the deficiencies are corrected. Before taking up the other eye for surgery, ensure patent sac syringing in both eyes, and allow adequate time interval between surgeries to settle the inflammation in the eye treated for endophthalmitis.