Method: In this retrospective study, we reviewed the medical records of all cases of endophthalmitis occurring in patients from 2016 to 2022. A detailed medical and ocular history, age, gender, documentation of medications, days to the presentation of symptoms, best corrected visual acuity (BCVA), anterior and posterior segment examinations, intraocular pressure (IOP), humor aqueous, and vitreous culture results, and length of follow-up were collected from the patient?s charts. We analyzed the differences between culture-positive eyes and culture-negative eyes.

Results: 18 cases of acute endophthalmitis were identified. Post-intravitreal injection endophthalmitis was the most common type with a rate of 50%. Culture positivity was detected in 10 (55.5%) patient samples. Signs and symptoms such as pain, lid swelling, redness, hypopyon, anterior chamber fibrin reaction, and vitreous haze were more in the culture-positive group, but there was no significant difference between the two groups (p>0.05). The increase in BCVA in the culture-negative group was significantly higher than in the culture-positive group (p=0.025). Postoperative complications were distinctly more in culture-positive patients.

Conclusion: Culture positivity affects negatively both visual and anatomical results after immediate PPV in patients with endophthalmitis. Eyes with low BCVA are more likely to be culture positive. Keywords : Endophthalmitis, pars plana vitrectomy, culture-positivity