Post Diabetic Vitrectomy Taut ILM Syndrome: A Cause of Diffuse Diabetic Macular with Clinical-pathological Correlation

Abstract

Purpose: : To report a unique entity entitled Post Diabetic Vitrectomy Taut ILM Syndrome with clinical-pathological correlation as a cause of diffuse macula edema following diabetic vitrectomy unresponsive to laser, corticosteroids, and anti-VEGF therapy.

Methods: : Clinical-pathological cases.

Results: : Two patients were referred for unresponsive diffuse diabetic macular edema following pars plana vitrectomy with removal of the posterior hyaloid. A taut internal limiting membrane was noted to extend over the fovea in both eyes. Internal limiting membrane removal was performed with rapid resolution of the macula edema and improvement in visual acuity. Improvement persisted for over one year with restoration of the normal foveal contour by ocular coherence tomography. Histopathology revealed a segment of internal limiting membrane with a monolayer of cells on the inner surface. Immunostaining of the cells revealed GFAP positive (glial cells) in both eyes and CAM 5.2 positive (RPE cells) in one eye with smooth muscle actin immunoreactivity consistant with myofibroblastic differentiation. No residual cortical vitreous was identified.

Conclusions: : A taut internal limiting membrane can cause diffuse diabetic macular edema following vitrectomy. When present its removal can decrease retinal edema, restore normal foveal contour and improve visual acuity. Tangential tractional forces by contractile glial and retinal pigment epithelial cells propagated across the fovea via the internal limiting membrane appear to be the etiology.

Keywords: diabetic retinopathy • vitreoretinal surgery • pathology: human