Infectious endophthalmitis is a rare yet severe complication of intraocular surgery, trauma and systemic illness. It’s unlikely that a patient will contract the disease more than once in their lifetime, but when it does occur, it’s important to understand the risk factors and etiology for recurrent endophthalmitis. An analysis of these rare, repeat cases showed that recurrent endophthalmitis was most often seen following intravitreal injections.

Patients who were diagnosed with and treated for endophthalmitis at least twice were included in this retrospective, single-center, consecutive case series. Those who received multiple treatments for the same episode were excluded.

The researchers identified 535 charts, of which 12 patients met inclusion criteria. The median age at initial presentation was 72.5 years, and one-third of the patients were male. Eight of the 12 patients had recurrent endophthalmitis in the same eye, and four had separate episodes in different eyes. The average time between episodes was 604 days (range: 90 to 2,366 days), and average follow-up from the second episode was 492 days (range: 119 to 1,185 days).

Recent intravitreal injections, followed by surgery-associated incidences, were the most common etiologies. Coagulase-negative Staphylococcus was the most commonly identified pathogen (41.6% positive) cultured from the 24 episodes of endophthalmitis.

The researchers say that final visual outcome worsened after each successive episode of endophthalmitis. Additionally, they note that “the cumulative number of intravitreal injections may be an independent risk factor for recurrent post-injection endophthalmitis.”