Postoperative Endophthalmitis

   Postcataract surgery acute Endophthalmitis

•Onset < 6 weeks of surgery

ØFulminant : within 48 hrs of surgery

                    - severe lid edema, conj. congestion

                    - ring infiltrates on cornea

                    - hypopyon > 1.5 mm

                    - RAPD

                    - yellow fundal  glow

                    - involvement of surgical wound

ØNon fulminant : signs & symptoms less severe

    

Endophthalmitis rates

•0.189% for clear corneal cataract extraction 

•0.074% for scleral incisions and

•0.062% for limbal incisions

 Risk factors:

•Wound abnormalities

•Vitreous loss

•Prolonged surgery

•Diabetes

•Contaminated irrigating solutions

•Most common microorganisms involved

•Fulminant endophthalmitis: gram –ve bacteria ( P. aeruginosa)

•Non fulminant : coagulase –ve staphylococci( S. epidermidis)

The most common symptoms reported in the Endophthalmitis Vitrectomy Study (EVS) were

•blurred vision in 94% of patients

•red eye in 82% of patients

•pain reported by 74% of patients

Signs

•hypopyon in 86% of patients in the EVS

•In 79% of EVS patients, no view of the retinal vessels was possible with indirect ophthalmoscopy

•red reflex was present in only 32% of patients

Ultrasonography is helpful  especially in cases with significant anterior segment media opacity 

•To confirm the presence of vitreous cells,  retinal or choroidal detachment or both, retained lens remnants in the posterior segment

•Findings suggestive of endophthalmitis are -

                         -Dispersed vitreous opacities with vitiris

                         -Chorioretinal thickening

 Management

•Vitreous specimen is obtained by either vitreous needle tap or by vitreous biopsy with a cutting/aspirating probe

•0.2 ml is obtained

Intravitreal therapy for bacteria

•Vancomycin 1.0 mg/0.1 mL

•Cefazoline 2.25 mg/0.1 mL

•Amikacin 400 ug/0.1 mL

•Dexamethasone 400 ug/0.1 ml

For fungi

•Amphotericin B 5 ug/0.1 mL

Voriconazole 1 mg/0.1 ml

•The role of systemic antibiotic therapy had been controversial in postoperative endophthalmitis, but the EVS reported no difference in final visual acuity and media clarity with or without the use of systemic antibiotics for acute postcataract extraction endophthalmitis

•In acute-onset postcataract extraction endophthalmitis, the EVS showed that in the subgroup of patients who had initial light perception, vitrectomy produced a threefold increase in the frequency of achieving 20/40 vision or better, a twofold increased chance of achieving 20/100 vision or better, and a 50% decrease in the frequency of severe visual loss.

Delayed Postoperative Endophthalmitis (> 6 weeks)
Usually manifest several weeks or months after surgery
Less common than acute variety
Organisms isolated are less virulent bacteria and fungus
P acnes,  S epidermidis, Candida parapsilosis

•The clinical picture may be indistinguishable from that of anterior uveitis. Patients may complain of photophobia, blurred vision, and mild pain. Keratic precipitates with anterior chamber and vitreous cells and flare can be seen. A capsular plaque may be seen in cases of P. acnes endophthalmitis

•A new onset inflammation after Nd:YAG laser capsulotomy may suggest infection due to release of previously sequestered low-virulence organisms into the vitreous

•Delayed endophthalmitis caused by P. acnes requires surgery, not only to confirm the diagnosis but also to remove any sequestered infectious material from the posterior capsule with concurrent injection of intravitreous antibiotics, usually vancomycin.

•If this is not successful, complete en bloc removal of the intraocular lens implant and capsular bag is necessary.