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[Contamination of intraocular fluid in pars plana vitrectomy]
Unlabelled:
Endophthalmitis after pars plana vitrectomy is rare, with an incidence of 0.05-0.14%. The aim of this study was to evaluate the microbiological situation during pars plana vitrectomy and to ascertain what organisms and how many enter the eye during the operation.
Patients And Methods:
Twenty-five consecutive subjects undergoing primary pars plana vitrectomy were included in the study. Patients were excluded if they had evidence of local or systemic infections or had undergone antibiotic therapy within 3 weeks before surgery. A standard three-port pars plana vitrectomy was performed on each patient. Preoperative smears of the conjunctiva and intraoperative aspirates of the vitreous were taken immediately after sclerotomy, and aspirates of the intraocular fluid at the conclusion of operation.
Results:
We obtained preoperative smears from the conjunctival sac of all patients, and found that 19 patients (76%) had positive cultures, with coagulase-negative staphylococci as the most commonly isolated organisms, (n = 14; 56%). Vitreous--aspirated immediately after sclerotomy--was sterile in 68% (n = 17). In 32% (n = 8) contamination occurred, the microorganisms isolated being coagulase-negative staphylococci (20%) and Staphylococcus aureus (12%). Five of the samples (20%) of intraocular fluid from the vitreous cavity--aspirated before wound closure--were contaminated, coagulase-negative staphylococci (8%) and Staphylococcus aureus (12%) again being found in culture. In no case did postoperative endophthalmitis develop.
Conclusions:
This study demonstrates that bacteria enter the eye during pars plana vitrectomy and that there is a change in the contaminating bacterial species during operation. Even if bacteria remain in the eye after pars plana vitrectomy, postoperative endopthalamitis does not necessarily develop.
Insights
Bacteria can enter the eye during pars plana vitrectomy (PPV), but postoperative endophthalmitis is rare. This study evaluated microbial contamination during PPV, finding that while bacteria are present, they don't always lead to infection.
Area of Science:
- Ophthalmology
- Microbiology
- Surgical Infections
Context:
- Pars plana vitrectomy is a common surgical procedure for various retinal conditions.
- Endophthalmitis is a rare but serious complication following intraocular surgery, with an incidence of 0.05-0.14% after pars plana vitrectomy.
- Understanding microbial contamination during surgery is crucial for preventing postoperative infections.
Purpose:
- To evaluate the microbiological environment during pars plana vitrectomy.
- To identify specific organisms and quantify their entry into the eye during the procedure.
- To assess the correlation between intraoperative contamination and the development of postoperative endophthalmitis.
Summary:
- Preoperative conjunctival cultures showed 76% bacterial colonization, predominantly coagulase-negative staphylococci.
- Intraoperative vitreous aspirates revealed contamination in 32% of cases (coagulase-negative staphylococci and Staphylococcus aureus).
- Intraocular fluid samples before wound closure showed contamination in 20% of cases, with similar organisms identified. No cases of postoperative endophthalmitis occurred.
Impact:
- Demonstrates that bacterial entry into the eye is a common occurrence during pars plana vitrectomy.
- Highlights a shift in contaminating bacterial species during the surgical procedure.
- Suggests that the presence of bacteria in the eye post-vitrectomy does not invariably result in endophthalmitis.