Purpose:
To describe retinal surface imaging by Spectral Domain Optical coherence Tomography (SD-OCT) after Epiretinal Membrane (ERM) with Internal Limiting Membrane (ILM) peeling.
Methods:
A retrospective cohort study of 43 eyes of 42 patients (70,6 ± 8,9 years) operated for ERM from January 2009 to May 2011 was conducted. Pars plana vitrectomy was combined with ERM removal and brilliant blue G assisted ILM peeling in all eyes. All patients were operated by the same surgeon. Best corrected visual acuity (BCVA), blue light images and SD-OCT (Spectralis HRA + OCT, Heidelberg Engineer, Heidelberg, Germany) of the macular region were performed before and 6 months after surgery to determine the post surgical OCT pattern of the inner retinal surface.
Results:
Log MAR BCVA, significantly improved after surgery (0,46 ± 0,23 vs. 0,19 ± 0,18, p<0.001). In 43 eyes (100%) we observed a new pattern in which the Retinal Nerve Fiber Layer (RNFL) and sometimes the Ganglion Cell Layer (GCL) lost the normal profile and became wavy; we called this feature "Inner Retinal Waves" (IRWs). IRWs were only present in the temporal macular area. In 22 eyes (51%) we also observed the thinning of the temporal macula. Blue light images were taken in 14 eyes (32,5%), 2 of which (14,3%) presented Dissociated Optic Nerve Fiber Layer (DONFL).
Conclusions:
Inner Retinal Waves (IRWs) were presented in all cases after ERM surgery with ILM peeling. We think the IRWs represent a loss of RNFL and GCL similar to what has been described in DONFL. In the subgroup of patients who had evidence of DONFL by blue light images, SD-OCT scans through the DONFL area demonstrated deep waves. In conclusion SD-OCT scan may be more sensitive than blue light photographs in detecting post ILM peeling alteration of the inner retinal surface.
Keywords: retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical