Spectral Optical Coherence Tomography in Diseases Affecting the Macula: Monitoring Morphological Changes Over Time

Abstract

Purpose: : To evaluate the capability of high-speed high-resolution spectral optical coherence tomography (SOCT) technology to monitor morphological changes over time in patients with choroidal and retinal diseases.

Methods: : This was a retrospective study involving patients with choroidal and retinal diseases imaged with SOCT between November 2007 and September 2008 at a single center in Brazil. Patients presenting at least three SOCT evaluations utilizing the volume (49 B-scans [lines] density, "high-resolution" mode, and automatic real time [ART] mean module set at 25 images) scanning protocol for covering a fundus area of 20ºx20º and the built-in eye-tracking software tool for automatic follow-up evaluations, which were consecutively performed in a time interval greater than 1 week, were eligible for the study. Positioning artifacts between SOCT evaluations were checked for each exam, and those presenting adequate alignment of the central B-scan as well as of others four B-scans (2 located superiorly and 2 located inferiorly within the macula) were included in study.

Results: : One hundred forty-five eyes of 108 patients with central serous chorioretinopathy, early and late age-related maculopathy, epiretinal membranes, macular edema associated with vascular diseases and diabetic retinopathy, retinal dystrophies, were eligible for the study. Seven (4.83%) eyes were excluded from the study (incomplete volume scanning session during any follow-up evaluation in 5 eyes, and misalignment of the scanning area in 2 eyes). In the 138 eyes included in the study, the fundus area scanned at follow-up evaluations corresponded precisely with that imaged at baseline. This alignment enabled the identification of presumably real, occasionally subtle and clinically underappreciated, morphological macular changes at the level of the vitreoretinal interface, neurosensory retina, and retinal pigment epithelium during follow-up.

Conclusions: : The use of a customized high-resolution high-density scanning protocol and built-in software tools for follow-up evaluations enabled precise correspondence of the fundus area imaged with SOCT at baseline with the area imaged at subsequent consecutive follow-up visits in 95.17% of the patients with diseases affecting the macula.

Keywords: imaging/image analysis: clinical • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)