Background: Triamcinolone acetonide (TA) has recently been used to treat diabetic macular edema (DME) but its effectiveness is limited.
Cases: Three patients (three eyes) with unresolved diffuse DME who did not respond to a posterior sub-Tenon's injection of TA underwent vitrectomy.
Observations: Intraoperatively, it was found that all of the eyes had a posterior hyaloid face that was adherent to a large area of the posterior pole retina, although this had not been detected by slit-lamp biomicroscopy or optical coherence tomography. After vitrectomy and removal of the posterior hyaloid face, there was a significant reduction in the central macular thickness of all three eyes and an improvement in the visual acuity of the patients.
Conclusions: When TA treatment is not effective for DME, vitrectomy with the complete removal of the posterior hyaloid face, including removal of the internal limiting membrane, should be considered.