Purpose:
To assess the microarchitectural changes of macular hole (MH) anatomy following surgical manipulations with intraoperative optical coherence tomography (iOCT) and an automated segmentation algorithm.
Methods:
A consecutive case series of ten eyes with full-thickness MH were analyzed with iOCT at multiple points during surgical repair. All eyes underwent vitrectomy and peeling of the internal limiting membrane (ILM). Pre-peel and post-peel iOCT images were obtained with a microscope-mounted spectral domain OCT device. An automated software algorithm was developed to segment the boundaries of the MH in consecutive B-scans allowing for high resolution measurements of numerous dimensions of the MH architecture. A three-dimensional representation of the MH was generated from the composite segmentation (Figure 1).
Results:
Ten of 10 eyes were successfully imaged with iOCT at numerous time points and analyzed utilizing the segmentation algorithm. Following ILM peeling, there was a significant increase in mean MH volume (0.18 vs 0.14 mm3, p<0.005) and base diameter (1334 vs 1073 microns, p<0.02). There was a trend towards increased MH height (504 vs 462 microns, p=0.09) and decreased apical diameter (540 vs 647 microns, p=0.06). Additionally, there was a significant reduction in the apical/basal diameter ratio following ILM peeling (0.62 to 0.37, p<0.005).
Conclusions:
MH anatomy undergoes significant changes during surgical repair. Assessment with iOCT suggests significant increase in MH volume and basal diameter following peeling of the ILM. Automated segmentation of MH is feasible with resulting volumetric measurements. This high-resolution three-dimensional measurement system combined with iOCT may help to identify MH features that impact surgical outcomes and management.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • macular holes • vitreoretinal surgery