Comparative analysis of macular microstructure by spectral-domain optical coherence tomography before and after silicone oil removal

Abstract

Purpose: To document comparative analysis of macular microstructures before and after silicone oil (SO) removal via spectral-domain optical coherence tomography and to assess the retinal changes associated with visual outcome.

Methods: Forty-six eyes that underwent vitrectomy with SO tamponade were included. Ophthalmic examinations were performed before SO removal and at Months 1, 3, and 6 postoperatively including best-corrected visual acuity and spectral-domain optical coherence tomography. The macular microstructures identified by spectral-domain optical coherence tomography were compared before and after SO removal, and tomographic parameters related to visual outcome were analyzed.

Results: Under SO tamponade, spectral-domain optical coherence tomography demonstrated macular tomographic findings: epiretinal membrane in 12 eyes (26.1%), cystoid macular edema in 9 (19.6%), undulated inner retina in 8 (17.4%), and submacular fluid in 4 (8.7%). The mean duration of SO tamponade was significantly longer in eyes with macular changes (6.3 ± 4.6 months) than those without changes (5.2 ± 4.4 months) (P = 0.02). A total of 13 eyes had peeling of epiretinal membrane or internal limiting membrane combined with SO removal. After SO removal, most of microstructural changes were resolved. In the eyes with macular epiretinal membrane or cystoid macular edema, final best-corrected visual acuity was significantly improved compared with baseline (P = 0.017, 0.049), which paralleled the decrease of central foveal thickness. Restoration of photoreceptor layer and external limiting membrane was achieved in 2 (4.9%) and 5 eyes (12.5%), and those with continuous photoreceptor layer or external limiting membrane had the better final best-corrected visual acuity.

Conclusion: Under SO tamponade, macular microstructural changes were identified by spectral-domain optical coherence tomography and were associated with duration of SO tamponade. Most of the microstructural changes were recovered after SO removal, if needed, combined with macular surgery. Anatomic resolution was accompanied by postoperative visual improvement.