**8. Post-traumatic infectious endophthalmitis**

Post-traumatic endophthalmitis is an uncommon yet devastating complication of open globe injuries. It has a poorer outcome compared to postoperative endophthalmitis due to concomitant ocular tissue damage, presence of more virulent pathogens, and possibly due delay in diagnosis and treatment.

The reported incidence of infectious endophthalmitis following open globe injuries ranges from 3.1% to 11.9% of open globe injuries in the absence of an intraocular foreign body (IOFB) [47–52]. The incidence increases from 3.8% to 48.1%, in the presence of an IOFB, with higher infection rates with retained IOFBs contaminated with organic matter from a rural setting [53–57].

The following factors are associated with an increased risk of post-traumatic endophthalmitis: intraocular foreign bodies (IOFB) [58–62], violation of the lens capsule [58, 60–62], contamination of the wound [59, 61] and delayed primary repair [58, 61, 63]. Interestingly, the existence of hyphema or iris prolapse was associated with lower rates of endophthalmitis [64].

Recognizing symptoms of post-traumatic endophthalmitis might be challenging due to the presence of injury-induced inflammation and the disruption of ocular structures [65]. Pain and decreased visual acuity often occur with ocular injury with or without infection. Presence of worsening symptoms of photophobia, tearing and pain are suggestive of infectious endophthalmitis. Pain from ocular injury can be distinguished from that of endophthalmitis if it is progressive and out of proportion to the degree of injury [66–70]. Inflammatory signs are almost similar to other types of endophthalmitis (i.e., eyelid edema, chemosis, corneal edema, hypopyon, variable degree of vitritis, etc.), however, purulent discharge from the site of injury is a feature of post-traumatic endophthalmitis. Inflammation that progresses slowly following primary repair may be indicative of fungal endophthalmitis [67, 69].

The broad spectrum of pathogens causing post-traumatic endophthalmitis, with gram-positive cocci the most frequently identified causative organism, followed by Bacillus species, fungi, and mixed infections. In a large cohort of post-traumatic endophthalmitis cases, Long et al. have reported that 38.1% of cases of post-traumatic endophthalmitis were culture-positive, and 3.2% showed mixed infections (gramnegative bacilli and fungi). Culture proven pathogens included gram-positive cocci (41.9%), gram-negative bacilli (29.1%), gram-positive bacilli (12.3%), and fungi (16.8%). In the same reported series, the coagulase-negative staphylococcal (CNS) species S. epidermidis (21.8%) and S. saprophyticus (12.0%) were the predominant pathogens, followed by Bacillus subtilis (8.7%), Pseudomonas aeruginosa (7.8%),

**Figure 4.**

*Post-traumatic endophthalmitis with IOFB. Intraoperatively photos showing densely infiltrated vitreous suggest aggressive organism (4a) and large IOFB being removed with suture snare (yellow arrow) (4b). (Courtesy of Dr. Hemant Trehan).*

and Escherichia coli (6.4%). Delayed repair over 24 hours and metallic injury were significantly associated with a positive culture of CNS. The most frequent fungal species were Aspergillus (33% ), followed by yeast-like fungi (30% ) [51]. In another cohort of post-traumatic endophthalmitis; Clostridium perfringens were isolated in 16.6% of culture-positive cases [71].

To reduce the risk of post-traumatic endophthalmitis, it is widely accepted common practice to immediate initiation of empirical prophylactic systemic antibiotics (either intravenous or oral administration) at initial presentation for all open globe injuries and an injection of intravitreal antibiotics at the time of primary repair for high-risk patients [72–75].

In a meta-analysis report, it has been noted that the incidence of endophthalmitis post open globe injuries has reduced significantly when intravitreal/intracameral antibiotics were used intraoperatively without additional benefit on the final visual outcome [76].

The threshold for vitrectomy in cases of post-traumatic endophthalmitis is low. Vitrectomy should be performed if there is no response to intravitreal antibiotics within 24 hours or if associated with complications like retinal detachment or intraocular foreign body (**Figure 4**)**.**

In general, the visual prognosis of post-traumatic endophthalmitis is worse than that of post-operative endophthalmitis [77, 78]. The virulence of the microorganisms in post-traumatic endophthalmitis, for example, Bacillus cereus carries a very high risk of progressing to a final visual acuity of NLP [79]. A delay in diagnosis and initiation of appropriate therapy is an important risk factor that contributes to poor visual prognosis. Moreover, the presence of an afferent pupillary defect, perforating injury, expelled lens, corneoscleral wound (vs corneal wound), and retinal detachment at the time of ocular injury is associated with a poor visual prognosis even in the absence of endophthalmitis [80].
