Yvette Marie B. Santiago

Dr. Yvette Marie Santiago completed her clinical fellowship in Ophthalmic Plastic Surgery at Massachusetts Eye and Ear, Harvard Medical School in 2011. She is currently an active consultant at St. Luke’s Medical Center Eye Institute-Quezon City, Philippines, and a Clinical Assistant Professor at St. Luke’s College of Medicine.



Raymond Nelson C. Regalado

Dr. Raymond Nelson C. Regalado finished his clinical and surgical fellowship in External Disease and Cornea at the Philippine General Hospital in 2014. He is currently an associate active consultant at the St. Luke’s Medical Center Eye Institute, Philippines.


Endophthalmitis, one of the most dreaded ocular complications, is defined as an inflammatory condition of the inner contents of the globe affecting the aqueous and the vitreous (Fig. 8.1). This condition is typically caused by infection with bacteria or fungi.


Fig. 8.1


Infectious endophthalmitis may be classified according to inciting event, chronicity, etiologic agent, and source of infection as summarized in Table 8.1.

Table 8.1
Classification of infectious endophthalmitis



Inciting event

(a) Postsurgical endophthalmitis: occurs after ocular surgery (e.g., post-cataract surgery, post-vitrectomy, post-intravitreal injection, filter-bleb associated)

(b) Post-traumatic endophthalmitis


(a) Acute

(b) Subacute

(c) Chronic

Etiologic agent

(a) Bacterial

(b) Fungal

Source of infection

(a) Exogenous

(b) Endogenous

Postsurgical endophthalmitis occurs after ocular surgery (e.g., post-cataract surgery, post-vitrectomy, post-intravitreal injection, filter-bleb associated), while post-traumatic endophthalmitis occurs after open-globe injury or trauma with or without intraocular foreign body (IOFB).

Sources of infection for exogenous endophthalmitis are the skin flora or other external contaminants. Endogenous endophthalmitis, on the other hand, is seen in immunocompromised individuals and those with underlying systemic infection.


Open-globe injury has about a tenfold higher rate of infection compared to intraocular surgery. Among infectious endophthalmitis, post-traumatic endophthalmitis comprises up to 31 % of cases. Several reviews have reported higher rates of infection with vegetable or organic IOFB than metallic ones [1]. However, a report from the National Eye Trauma System (NETS) Registry did not see significant difference among various types of IOFB [2]. The number of reported endophthalmitis has decreased through the years with the development of more effective antibiotics and improved prophylactic management.

Postsurgical Endophthalmitis

Risk Factors

Risk of postsurgical endophthalmitis can be due to factors inherent in the patient, surgical technique, and postoperative course as enumerated in Table 8.2 [3].

Table 8.2
Risk factors of infectious endophthalmitis

Postsurgical endophthalmitis

Patient factors:

 (a) Conjunctival and periocular flora

 (b) Pre-existing periocular infections

 (c) Systemic infection

 (d) Diabetes and other immunocompromised states

Surgical factors:

 (a) Bacterial contamination of the aqueous during surgery

 (b) IOL material

 (c) Incision type

 (d) Prolonged and complicated surgery

Postoperative factors:

 (a) Vitreous wick

 (b) Wound leaks

 (c) Infected wound edges

Post-traumatic endophthalmitis

 (a) Retained intraocular foreign body

 (b) Delayed primary wound closure of more than 24 h

 (c) Lens rupture

 (d) Rural setting

Among factors inherent to the patient, pre-existing periocular infections such as bacterial blepharitis and dacryocystitis can increase the risk of aqueous contamination during surgery.

Bacterial contamination of the aqueous may also occur from improperly sterilized instruments, contaminated surgical field and fluids, and use of intraocular lenses (IOLs) with polypropylene haptics and silicone implants. IOLs made from the aforementioned materials have a higher risk of bacterial adherence compared to polymethyl methacrylate and acrylic hydrophobic IOLs [46].

Clear corneal incision, likewise, increases the risk two- to threefold more than corneoscleral incision (0.13 %) [7]. Prolonged and complicated surgery with posterior capsular rent and/or vitreous loss may increase risk of aqueous bacterial contamination. Postoperative factors that increase likelihood of endophthalmitis are due to wound abnormalities such as vitreous wick, wound leaks, and infected wound edges (Fig. 8.2).


Fig. 8.2
Slit lamp photo of endophthalmitis showing hypopyon, anterior chamber cells, and conjunctival injection

Clinical Features

Acute postsurgical endophthalmitis may present with progressive eye pain, conjunctival congestion, and decreased visual acuity. Examination would show anterior chamber inflammatory cells with fibrin formation, hypopyon (Fig. 8.3), vitreous cells, and fibrin [8].


Fig. 8.3
Endophthalmitis after complicated cataract surgery, with vitreous wick on the corneal incision

Chronic post-cataract surgery endophthalmitis presents as a milder disease that causes loss of vision and mild eye pain. Presenting signs include cells in the anterior chamber, hypopyon, and a plaque on the posterior chamber capsule. Mild vitritis is also sometimes present.

Intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) into the vitreous cavity carries a small risk of postinjection endophthalmitis. Symptoms occur within 1–6 days after injection with around 80 % presenting with hypopyon [9].

A particular kind of postoperative endophthalmitis is filter-bleb-associated endophthalmitis. It is one of the long-term complications of trabeculectomy that has major implications for visual loss. It occurs as a sequela to blebitis. Presenting signs and symptoms are similar to other forms of infectious endophthalmitis, in addition to mucopurulent material seen in the filtering bleb [10] (Fig. 8.4).


Fig. 8.4
Filter-bleb-associated endophthalmitis with blebitis

Microbiologic Isolates

The most common pathogen in postsurgical endophthalmitis is coagulase-negative Staphylococcus. The Early Vitrectomy Study (EVS) examined cases of post-cataract surgery endophthalmitis and found that infection caused by more virulent strains such as gram-negative organisms and gram-positive organisms other than coagulase-negative Staphylococcus presented within 2 days of surgery and with worse symptoms [11].

Chronic post-cataract endophthalmitis is caused by Propionibacterium acne.


The principal step in treating postsurgical endophthalmitis is with intravitreal injection of antibiotics (Table 8.3). The intravitreal antibiotics of choice are vancomycin (1 mg) for gram-positive coverage and amikacin (0.4 mg) or ceftazidime (2.25 mg) for gram-negative strains. A single dose is usually sufficient to control infection. Poor or none response to treatment may be due to infection with virulent organisms, like Streptococci sp. and Pseudomonas, and resistant organisms. In cases of poor clinical response, a second intravitreal injection is recommended after 48 h. Since repeated injections of these antibiotics suggest increased risk of retinal toxicity, this practice is not recommended unless necessary.

Table 8.3
Suggested antibiotic treatment regimens for bacterial endophthalmitis

Route of administration

Medication and suggested dose


Fortified antibiotics: vancomycin 50 mg/mL and cefazolin 50 mg/mL alternating q1–4H

Gatifloxacin 0.5 % or moxifloxacin 0.5 % q1–2H


Vancomycin 50 mg/mL, 1 mg/dose

Amikacin 0.4 mg or ceftazidime 2.25 mg


Vancomycin 5 mg and

Ceftazidime 100 mg or amikacin 25 mg


Cefuroxime 1 mg or

Moxifloxacin 0.5 % 0.1 mL


Vancomycin 1.0 g IV q 12 hand

Ceftazidime 1–2 g IV q 8 h

Ciprofloxacin 750 mg PO q 12 h or ofloxacin 400 mg PO q 12 h

Prednisone 1 mg/kg/day PO

Vitrectomy helps to restore media clarity faster, obtain a better sample for culture, and remove bacterial toxins and inflammatory cells. The EVS remains to be the most extensive prospective trial that studied several aspects in management of post-cataract endophthalmitis. In their study to compare the benefit of performing vitrectomy over vitreous tap alone, they found that there was no apparent benefit to doing vitrectomy in patients with hand motion vision or better [12]. Still, vitrectomy is preferred by some surgeons in patients with severe visual loss or rapidly deteriorating vision and those where virulent bacteria has been isolated.

Fortified antibiotic eyedrops and/or fourth-generation fluoroquinolones may also be given, adjunctively, every 1–4 h as topical treatment. Subconjunctival antibiotics, likewise, may be injected to decrease bacterial load in aqueous although this is less often applied (Table 8.3).

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Oct 16, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Endophthalmitis

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