**3. Risk factors**

Multiple factors increase the likelihood of APIE in patients undergoing intraocular surgery. Some intraoperative complications such as posterior capsular rupture with or without vitreous loss, hypotony with aqueous humor filtration, especially in cases of clear corneal wounds and increased manipulation of intraocular tissues, are some factors that may raise the possibility of developing infectious endophthalmitis [3, 4, 11, 12].

The presence of inflammatory-infectious processes on the ocular surface or adnexa, such as conjunctivitis, keratitis, blepharitis, and dacryocystitis also, increases the incidence of endophthalmitis [4]. Additional systemic factors include advanced age [12] and chronic systemic debilitating diseases, such as diabetes mellitus (DM), malignancies, congenital or acquired immunodeficiencies and immunosuppression [3, 4, 12]. Patients with DM represent significant changes in the conjunctival flora, representing an important subgroup of patients who might develop endophthalmitis [3, 4].

APIE risk factors after anti-VEGF intravitreal injections, include not wearing a face mask, not using povidone prior to the injection and speaking while performing the injection [12].

A systematic review and meta-analysis [11] of the risk factors for APIE following cataract surgery, reported that there is a significant association between male gender and APIE. The overall OR for male gender was 1.43 (95% CI 1.29, 1.58). There was a significant association between extra- or intracapsular cataract extraction and APIE (OR 2.19, 95% CI 1.40, 3.42) compared with phacoemulsification. Furthermore, intracameral cefuroxime had a protective effect against APIE compared with topical antibiotics alone (OR 5.48, 95% CI 3.79, 7.92).

Analysis of the included retrospective studies in the meta-analysis showed that posterior capsular rupture was also a significant risk factor of APIE (OR 6.33, 95% CI 4.22, 9.49), and a significant increase in risk of APIE with other intraoperative complications (OR 4.95, 95% CI 2.31, 10.63) was observed, as well.
