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Updated: Apr 21, 2026
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Bleb-associated infections after intravitreal injection
Somanus Thoongsuwan1, Har Hiu Dawn Lam, Robert B Bhisitkul
1From the Department of Ophthalmology, University of California San Francisco School of Medicine, San Francisco, California.
Purpose:
The purpose of this study was to describe two cases of bleb-associated infections after intravitreal injection.
Methods:
Case reports of two patients. Case 1: A 41-year-old man with choroidal neovascular membrane received intravitreal injections of ranibizumab. Case 2: A 56-year-old man with cystoid macular edema after retinal detachment surgery received intravitreal triamcinolone acetonide.
Results:
In Case 1, the patient developed a culture-negative blebitis 3 days after intravitreal ranibizumab and was treated with intravitreal, subconjunctival, and oral antibiotics. The infection resolved after 3 weeks, with stable 20/100 vision and preservation of bleb function. In Case 2, a bleb-associated endophthalmitis (positive for Streptococcus pneumoniae) occurred 3 weeks after intravitreal triamcinolone acetonide, requiring repeated intravitreal antibiotics and two vitrectomy procedures to control the infection, with final vision of hand motions.
Conclusion:
Bleb-associated infections can be a complication of intravitreal injection. The potentially severe results of bleb-associated endophthalmitis warrant monitoring in patients with previous trabeculectomy who undergo intravitreal injection therapies.
