QUANTIFICATION OF INTRARETINAL HARD EXUDATES IN EYES WITH DIABETIC RETINOPATHY BY OPTICAL COHERENCE TOMOGRAPHY
To evaluate the reproducibility of intraretinal hard exudate (HE) quantification from spectral domain optical coherence tomography (SD-OCT) images of eyes with diabetic retinopathy (DR).Methods:
Cases with diabetic macular edema were enrolled. The area of HE obtained by B-scan segmentation was compared with the area obtained by en face segmentation.Results:
The mean ± SD for the HE area was 1.78 ± 1.37 mm2 with B-scan segmentation and 0.72 ± 0.82 mm2 with the automated en face analysis tool; the absolute difference was 1.01 ± 0.64 mm2. There was excellent correlation in total HE area between the two methods (r = 0.95, P < 0.0001). The HE volume was 0.06 ± 0.07 mm2. The correlation between HE volume and en face HE area was high (r = 0.95, P < 0.001). Intergrader reproducibility yielded excellent agreement with an intraclass correlation coefficient value of 0.99 (95% CI 0.994–0.999) for the en face approach and 0.99 (95% CI 0.977–0.997) for manual segmentation.Conclusion:
Quantification of HE in eyes with diabetic retinopathy can be performed reliably using en face segmentation and, though the en face results are consistently lower, correlates well with HE measurements obtained by exhaustive segmentation of all B-scans in dense volume optical coherence tomography (OCT).