Visual Prognosis of Eyes Recovering From Macular Hole Surgery Through Automated Quantitative Analysis of Spectral-Domain Optical Coherence Tomography (SD-OCT) Scans.

Understanding the healing process after surgery for closure of macular holes (MHs) may provide insight into maximizing surgical success and predicting visual acuity (VA) outcomes. Spectral-domain optical coherence tomography (SD-OCT) is a widely used noninvasive, medical imaging technique to provide in vivo high resolution, cross-sectional three-dimensional images of the retina,1–5 allowing ophthalmologists to identify and quantify macular abnormalities in various vitreoretinal diseases such as MHs,6 providing valuable information before7 and after MH surgery,8 or to even assist intraoperatively.9,10 Advances in SD-OCT instrumentation and image analysis methods have led to the development of numerous automated intraretinal segmentation methods, both in commercial systems11 or by research groups,12–20 and tools to quantify macular disease progression.21 However, analysis of postoperative SD-OCT data in MH patients has not moved significantly beyond the manual annotation of defects in a single two-dimensional horizontal-scan through the foveal center.22 This manual assessment has two fundamental issues: The largest width of a defect may lie in an oblique axis,6 making measurements in horizontal-scans unreliable, and the lack of standardized measuring criteria adds an element of subjectivity when judging margins,22 leading to potential ambiguity. These issues may be the cause of ambiguity between previous reports studying the association of the integrity of the photoreceptor ellipsoid zone (EZ) band or the external limiting membrane (ELM)22–30 with VA in surgically anatomically closed MHs. While some studies demonstrated statistically significant correlation of VA with the diameter and area of EZ band defects,22–26 others reported no such correlation and gave more importance to defects involving the ELM.27–29 Another study did not find correlation of VA with either EZ band or ELM defects at times later than 6 months after surgery, but instead found correlation with the cone outer segment tips (COST) line.30 Findings predicting potential restoration of VA in surgically closed MHs have also not been sufficiently clarified. A study showed that a higher diameter of EZ band defects measured at 3 months after surgery was associated with poorer VA at 12 months,31 while others found such association not to be significant, but found that less extensive ELM defects measured shortly after surgery may indicate a higher chance of vision restoration at 626 or 12 months.28 Defects in the inner retinal layers, such as the nerve fiber layer (NFL), the ganglion cell complex (GCL), or the inner plexiform layer (IPL), mainly occurring in the temporal region, have also been reported and associated to lower visual function.32 Postsurgical inner retina defects, mainly caused by inner limiting membrane (ILM) peeling during the surgical procedure33 or by dye toxicity during intraoperative staining32,34 can be observed in SD-OCT images as localized dips in the ILM boundary translating in isolated regions of inner retina (IR) thinning23,28,34,35 with higher incidence in the supero-temporal region.36 However, such chronically persisting defects33 have not correlated with VA23,28 and an association with poorer vision recovery has also not been observed.28 This lack of association may be due to the limitations mentioned previously. Topographic measurements of postoperative defects in SD-OCT-derived en face images have been shown to be more reliable, with greater correlation with VA than when measured in cross-sectional images,22 and a robust automated method would eliminate subjective judgment. We have developed automated methods to quantify defects in the EZ band and the inner retina by extracting a set of image features related to defect topographic extent and location. We examined the correlation of these imaging features with VA in postoperative MH longitudinal SD-OCT scans, eliminating any subjective judgment and ambiguities derived from making measurements manually in cross-sectional scans.