B-scan ultrasonography and optical coherence tomography (OCT) in epiretinal macular membranes: pre- and post-operative evaluation

Purpose: This study was designed to evaluate B-scan ultrasonography and opt ical coherence tomography in the pre- and post-operative morphologic evalua tion of idiopathic epiretinal macular membranes. Methods: Fifteen eyes were examined using B-scan ultrasonography and optica l coherence tomography before and after surgical excision of the epiretinal macular membranes. Results: Ultrasonography prior to surgery allowed an excellent evaluation o f both the peripheral and the posterior vitreous and showed the membrane. T he thickening of the retina and the retinal folds were equally visualised b y either method. An improved observation of the macular oedema was obtained by the optical coherence tomography as well as the type of membrane adhesi on. After surgery, both methods were able to detect membrane remnants. A be tter vizualisation of retinal thickness and cystoid macular oedema was obta ined by optical coherence tomography rather than ultrasonography. Serous su b-foveal retinal detachment was only revealed by optical coherence tomograp hy. Discussion: Ultrasonography is indispensable in case of media opacity or of optical inaccessibility of the posterior pole. Moreover, it allows an exce llent global analysis of the anterior and posterior vitreous, which is very useful for the surgeon. The membrane is always showed by ultrasonography, but not always by optical coherence tomography in case of diffuse adherence . Both methods can detect the membrane and a cystoid macular edema. However , retinal analysis with the optical coherence tomography is more precise. I t can even detect cysts of the macular oedema or serous sub-foveal retinal detachment. Conclusion: B-scan ultrasonography and optical coherence tomogr aphy give complementary information in pre- and post-operative examination of epiretinal macular membranes.