Analysis of Longitudinal Ellipsoid Zone Features Following Intraoperative OCT-Assisted Macular Hole Repair and the Association with Functional Outcomes from the DISCOVER Study

Abstract

Purpose : Quantitative longitudinal outer retinal features, such as ellipsoid zone (EZ) loss, have not been historically feasible. Recent studies using spectral-domain optical coherence tomography (SD-OCT) have revealed that visual improvement occurs as the EZ is gradually restored following surgical macular hole (MH) closure, but quantitative assessment of these EZ changes has been limited. This study examines eyes from the DISCOVER study that underwent intraoperative optical coherence tomography (iOCT)-assisted MH repair surgery to investigate EZ dynamics and correlations with visual outcomes.

Methods : The DISCOVER study is a large-scale prospective consecutive case-series on the use of microscope-integrated iOCT in ophthalmic surgery. Eyes from the DISCOVER study that underwent MH repair were included in this study. Inclusion criteria included: (1) available preoperative SD-OCT and (2) available post-operative SD-OCT at month 1, 3, 6, and/or 12. Exclusion criteria included: (1) SD-OCT scans of limited quality not sufficient for analysis. Macular cube scans were imported into a novel EZ mapping platform. Multiple parameters were evaluated, including panmacular (e.g., EZ-RPE volume) and central macular [e.g., EZ-RPE central subfield thickness (CST)] features. Segmentation was reviewed by an expert image analyst and corrected for errors. Pearson correlation and multivariate linear regression was used for statistical analysis.

Results : A total of 84 eyes from 81 patients who underwent MH surgery were identified from the DISCOVER study with a mean age of 70.1 years. Multiple EZ-RPE parameters demonstrated significant improvement from baseline to 12 months, including EZ-RPE CST (15.91 µm to 36.3 µm, p<0.0001), EZ-RPE volume (1.15 mm³ to 1.26 mm³, p<0.0001), and EZ attenuation (2.6% to 0.7%, p<0.0001). The EZ-RPE mean CST significantly positively correlated with visual acuity (VA) at all timepoints (p < 0.001).

Conclusions : Functional outcomes in MH surgery repair was strongly correlated with EZ integrity and outer retinal metrics. Central macular EZ parameters were more linked to VA outcomes than panmacular metrics. Additional research is needed to further evaluate the relationship between anatomic features and functional features.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.