Ultrasound biomicroscopy study of vitreous incarceration subsequent to intravitreal injections

Abstract

ObjectiveTo study the existence of vitreous incarceration by ultrasound biomicroscopy (UBM) at the pars plana after direct intravitreal injection of triamcinolone acetonide ± bevacizumab without anterior chamber paracentesis. DesignInterventional case series. ParticipantsPatients undergoing intravitreal injection of triamcinolone acetonide with or without intravitreal bevacizumab. MethodsIn 21 eyes, the existence of vitreous incarceration at the pars plana site of intravitreal injection of 0.05 mL of drug was studied by UBM (50 MHz probe of the VUmax, Sonomed, NY), the day after surgery, by 1 technician. The reason for injection was diabetic retinopathy in 12 (57.1%) eyes; age-related macular degeneration in 6 (28.6%) eyes; branch retinal vein occlusion in 2 (9.5%) eyes; and choroiditis in 1 eye (4.8%). In 1 eye, only triamcinolone acetonide was injected, and in the other eyes, bevacizumab mixed with triamcinolone acetonide was injected. ResultsWe studied 21 eyes in 13 patients. Of the subjects, 61.5% were male. The mean age of the patients was 62.2 years. On the day after intravitreal injection of the drug, vitreous incarceration into the pars plana site was detected by UBM in 42.9% of the eyes. ConclusionVitreous incarceration exists after intravitreal injection of drug, but its clinical importance is still unknown. Further long-term prospective studies are recommended.