**5. Endophthalmitis Post Pars Plana Vitrectomy (PPV)**

Endophthalmitis post-PPV is relatively rare. The incidence has decreased from 0.3– 0.14% to 0.0180.076% with improvement in VR instrumentations and techniques [27].

There are several reported predisposing factors under this entity; insufficient wound closure, hypotony from a sclerotomy leak, and vitreous incarceration at a sclerotomy site, are some risk factors as it allows migration of microorganisms into the vitreous cavity from the ocular surface [28–30].

Patients may present with symptoms and signs similar to endophthalmitis following cataract surgery in particular hypopyon and dense vitritis (**Figure 3**).

Vitreous samples should be obtained if endophthalmitis is suspected. A combination of broad-spectrum intravitreal antibiotics is injected intravitreally.

Multiple studies have reported several bacteria under such entity which include coagulase-negative staphylococci, Pseudomonas species, Propionibacterium, enterococci, and Bacillus species. However, coagulase-negative staphylococci are the most common organism [31].

## **Figure 3.**

*Intraoperative photos of post PPV endophthalmitis. Intraoperatively photos showing dense vitritis suggestive of aggressive inflammation (3a) and clear vitreous after silicone oil removal (3b). (Courtesy of Dr. Hemant Trehan).*

EVS did not enroll patients with post-PPV endophthalmitis, therefore, the results do not directly apply to the management of such entity. Nevertheless, certain principles apply.

On average, about 70% of all samples across studies have shown positive microbiology cultures. In a large multicenter study, Cohen et al. reported16 culture-positive cases out of 18 cases (89%) of endophthalmitis post-vitrectomy [32].

Despite treatment, the visual outcome varies. As described by Park et al., a significant proportion of cases have poor visual outcomes, with vision ranging from 20/200 to no light perception [33]. However, some cases achieved 20/40 vision [34, 35].
