Semi-Automated Optical Coherence Tomography in Clinical Practice

Background: OCT has become a useful tool in research and clinical practice for evaluating MS patients with and without optic neuritis. Prior OCT scanners require technicians with considerable training and experience. The Optovue iScan is a small, portable, semi-automated OCT scanner, which provides verbal patient instructions with minimal training and consistent acquisition. 

Objectives: To evaluate retinal thicknesses using a portable OCT scanner and correlations with Pelli-Robson contrast charts.

Methods: The Optovue iScan was utilized to obtain retina map scans from 76 subjects with MS during their routine clinic visit. Subject demographics, disease history, optic neuritis history, and Pelli-Robson Contrast Scores were obtained. The iScan was used to obtain thicknesses and volumes of the foveal, parafoveal, and perifoveal layers of the retina.  Differences in eyes with and without a reported history of optic neuritis in retinal quadrant thickness and volume were evaluated using Independent T tests.  Correlations between scores on the Pelli Robson, volumes and thicknesses were performed.  

Results: Inner Retinal Thickness (Inner Limiting Membrane to outer limit of Inner Plexiform Layer) was decreased for eyes with a history of prior optic neuritis (hxON) for all quadrants (t =.437, p = .001), perifovea and parafovea. Inner Retinal Volumes were reduced for eyes with hxON for the parafovea, perifovea, but not the central fovea. Pelli-Robson Scores were moderately correlated with Inner Retinal Thicknesses across all quadrants (ρ = 0.328).

Conclusions: Semi-automated OCT is a valuable tool for evaluating inner retinal thicknesses in an MS population, and can be readily utilized in a busy clinical practice. Semi-automated OCT is sensitive to detect differences between eyes with and without a history of optic neuritis.