Abstract
Purpose: :
To measure the area and volume of pigment epithelium detachments (PEDs) in eyes with age-related macular degeneration (AMD) using spectral domain optical coherence tomography imaging (SDOCT) and a novel quantitative algorithm.
Methods: :
Patients with AMD-related PEDs were enrolled in this study. Five separate SDOCT scans were performed on each eye, using a Cirrus HD-OCT instrument (Carl Zeiss Meditec, Dublin, CA). Each scan consisted of 40,000 uniformly spaced A-scans organized as a 200 X 200 A-scan array and covered a retinal area of 6x6 mm encompassing the entire PED. A novel, fully automated, algorithm was used to quantitatively assess PED area and volume. Test-retest standard deviations of PED area and volume measurements were calculated for each eye. The same method was applied to assess the change in PED area and volume measurements after anti-VEGF therapy in a subset of patients.
Results: :
Sixty three eyes from 58 patients were included in the repeatability study. The algorithm created PED maps that permitted both qualitative and quantitative assessment of PED area and volume. Both the qualitative appearance and the quantitative measurements of PED area and volume were highly reproducible over the 5 different datasets. The intraclass correlation coefficient (ICC) was above 0.99 for both area and volume measurements for the entire dataset. Thirty one eyes underwent anti-VEGF therapy, and the effect of treatment on PED measurements was assessed. After anti-VEGF intravitreal injections, the mean PED area changed from 6.22 mm2 to 5.53 mm2 (p=0.078) and PED volume changed from 1.17 mm3 to 0.74 mm3 (p=0.04).
Conclusions: :
A novel algorithm for the qualitative and quantitative assessment of PEDs following SDOCT imaging was shown to be highly reproducible. The ability to measure PED volume reliably may represent a new quantitative parameter that may prove useful when following the natural history of these lesions and when assessing the response of these lesions to anti-VEGF therapy.
Keywords: imaging/image analysis: clinical • age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)