**2. Acute postoperative infectious endophthalmitis**

The onset of acute postoperative infectious endophthalmitis (APIE) onset is within 6 weeks from the intraocular procedure [3]. It has a typical presentation of severe ocular pain and reduction in vision. In addition; eyelid edema is observed in around one-third of the patients. The conjunctiva is congested and corneal edema is commonly present. Intraocular inflammatory signs (cells, fibrin, and hypopyon) are the main findings and these involve both anterior chamber (AC) and the vitreous cavity. The red reflex is usually absent in the affected eye. Hypopyon and fibrinous reaction in the AC are typical features of APIE. B-scan ultrasound, usually, reveals vitreous hyperechoic opacities due to vitritis (**Figure 1**).

The APIE can be also subclassified into early (within 7 days after surgery) or late (8 days to 6 weeks after surgery) [16]. The early type is usually caused by gram-negative bacteria and usually has worse visual acuity at presentation and carries a poor visual prognosis. However, the late type is usually caused by gram-positive bacteria (frequently coagulase-negative staphylococci) and the presenting visual acuity is usually better than the early type with better visual prognosis.

Early diagnosis and prompt intervention of APIE are crucial. The guidelines from Endophthalmitis Vitrectomy Study (EVS) are usually adopted to treat patients with APIE based on the visual acuity on presentation. If the affected eye has a visual acuity of hand motion or better than a tapping-injection procedure is recommended. Pars plana vitrectomy with vitreous specimen collection and intravitreal injection of antibiotics, is recommended for an eye with visual acuity of light perception or worse. According to EVS, tapping of the vitreous yields more positive microbial results than taping from the anterior chamber. Intravitreal injection of antibiotics should cover both gram-positive and gram-negative bacteria. The most common intravitreal antibiotics being used are vancomycin (1 gm/0.1 ml) and ceftazidime (2.25 mg/0.1 ml).

## **Figure 1.**

*Acute postoperative (phaco +PCIOL) endophthalmitis secondary to Serratia marcescens. Anterior segment photo of the right eye shows diffuse lid edema, diffuse and severe conjunctival chemosis, diffuse corneal cloudiness, organized hypopyon, iris details not visualized (1a) and B-scan shows diffuse vitreous hyperechoic opacities and attached retina (1b).*

Amikacin (0.4 mg/0.1 ml) can be used as an alternative for ceftazidime. The visual prognosis for an eye with APIE is promising after early and appropriate intervention. After 9–12 months of follow-up of treated eyes; 53% of eyes had visual acuity of 6/12 or better and only 11% had worse than 6/240 [3].
