Measurement and Reproducibility of Preserved Ellipsoid Zone Area and Preserved RPE Area in a Cohort of Eyes with Choroideremia.
Hariri AH., Velaga SB., Girach A., Ip MS., Le PV., Lam BL., Fischer MD., Sankila EM., Pennesi M., Holz FG., MacLaren RE., Birch DG., Hoyng CB., MacDonald IM., Black GC., Tsang SH., Bressler NM., Larsen M., Gorin MB., Webster AR., Sadda SR., For Natural History of the Progression of Choroideremia (NIGHT) Study Group None.
PURPOSE: To identify valid and reproducible methods for quantifying anatomical outcome measures for eyes with choroideremia (CHM) in clinical trials. DESIGN: Reliability analysis study. METHODS: In this multicenter study, patients with confirmed genetic diagnosis of CHM were enrolled. All cases underwent spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) imaging. Two graders independently delineated boundaries of preserved autofluorescence (PAF) and preserved ellipsoid zone (EZ) on FAF and OCT images respectively. The results of the two independent gradings of both FAF and OCT images were compared to assess the reproducibility of the grading methods. RESULTS: A total of 148 eyes from 75 cases were included. In 21% of eyes, PAF and in 43% of eyes preserved EZ had extended beyond the images captured area. After excluding these eyes and low quality images, 114 FAF and 77 OCT images were graded. The mean PAF area from two independent gradings were 3.720 ± 3.340 and 3.692 ± 3.253 mm2 respectively. Intraclass correlation coefficient (ICC) for these gradings was 0.996. The mean preserved EZ area from two independent gradings were 2.746 ± 2.319 and 2.858 ± 2.446 mm2 respectively. ICC for these gradings was 0.991. CONCLUSIONS: Quantifying preserved RPE and EZ areas on FAF and OCT images, respectively, in CHM patients is highly reproducible. These variables would be potential anatomical outcome measures for CHM clinical trials and could be studied and tracked longitudinally in choroideremia.