Primary Pars Plana Vitrectomy Practices May Increase Acute Endophthalmitis Rate

The incidence rate of acute endophthalmitis following 23-gauge primary pars plana vitrectomy (PPV) is 0.18%, according to a study published in the International Journal of Retina and Vitreous. This finding indicates a higher rate than previous research identified, according to the study authors.

The researchers retrospectively reviewed 6474 patients who underwent PPV between September 2011 and March 2017 at Khatam-Al-Anbia tertiary eye hospital in Iran. The study identified 12 patients (8 women, 4 men; mean age, 54.08±12.95 years) who developed acute post-vitrectomy endophthalmitis (APVE). Of those, 9 patients had a diabetes diagnosis and 1 had a hypertension diagnosis.

Indications for surgeries among the cases of endophthalmitis include diabetic retinopathy (8 cases), rhegmatogenous retinal detachment (2 cases), epiretinal membrane (1 case), and nonclearing vitreous hemorrhage due to central retinal vein occlusion (1 case). A tamponade agent was used in 5 cases (3 cases with silicone oil and 2 cases with gas).

Previous studies reported an incidence of acute endophthalmitis after PPV between 0.02% and 0.14%. The practice of reusing disposable vitrectomy devices in the center where the study was conducted may explain the increased incidence, according to the researchers. Immune system dysfunction is another factor claimed to increase the risk of infection among the patients with diabetes.

Although silicone oil is sometimes used to prevent endophthalmitis, the agent was used in 3 of the patients in this study who were diagnosed with endophthalmitis.

The hospital implements recommended measures to reduce the incidence of endophthalmitis, such as the application of 10% povidone-iodine, wound suturing, and postoperative subconjunctival and topical antibiotics.

“Evaluation of the patients’ vision in this study indicates a significant decrease (P =.002) following the incidence of APVE. The mean ±SD of visual acuity was 2.48±0.35 logMAR unit at the last follow-up visit (1 year after the incidence of APVE). This finding is consistent with the results of previous studies. It seems that APVE is acute and occurs shortly after vitrectomy, which often means that despite immediate and aggressive treatment, visual results are poor,” the researchers explain.

The limitations of this study include its retrospective nature and inability to assess the duration of the surgeries, a potentially important factor.