Abstract
Purpose :
Macular hole (MH) diameter is commonly measured manually on Spectral Domain Optical Coherence Tomography (OCT) horizontal B-scans. The purpose of this study was to evaluate the feasibility and the interest of MH size measurement on en-face OCT images.
Methods :
Retrospective analysis of 100 consecutive patients operated on for primary MH. Inclusion criteria were eyes for which OCT scans were acquired with Cirrus™5000 HD-OCT (Carl Zeiss Meditec, Dublin, CA) with good quality signal strength. Three segmentations (Internal Limiting Membrane, Horizontal and Retinal Pigment Epithelium) were compared for obtaining the most appropriate en-face image and MH surface area measurements. Surface areas were measured using the Image J software. Calculated diameters issued from the measured surface areas [diameter =2 x √ (surface area / π)] were compared to MH diameters measured on the horizontal B-scans.
Results :
Of the 100 patients, 19 had images on the Cirrus OCT and of sufficient quality for analysis. The mean patient age was 71.9 ± 8 years (range 56-86) and gender ratio was 3M/16F. The “Retinal Pigment Epithelium” segmentation provided the best en face image and was feasible without adjustment in 79% of cases, and in 100% when manually adjusted (cases with a vitreomacular traction). There was no significant difference between horizontal and vertical diameters measured on B-scans (426 ± 139 μm (range 214-705) and 410 ± 153 μm (range 148-647), respectively, p=0.874). Calculated diameters issued from the measured surface areas on en-face OCT images (435 ± 143 μm, range 195-693) was not significantly different from the diameters measured on the horizontal B-scans (p=0.482).
Conclusions :
MH area measurement on en-face OCT images is feasible, allows a reliable estimation of the MH size and eliminates potential bias inherent in the manual measurement on horizontal B-scan raster line. Automation of MH size measurement would be a simple option in clinical practice if integrated software in the OCT device allowed realizing it routinely. Moreover, en-face OCT can be used as a descriptive tool, such as for the presence of retinal pigment epithelium mottling or a concurrent epiretinal membrane.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.