Abstract
Purpose:
To assess functional and microstructural changes of photoreceptors after oral steroid treatment in patients with acute zonal occult outer retinopathy (AZOOR) by using microperimetry (MP) and spectral-domain optical coherence tomography (SD-OCT).
Methods:
In this prospective interventional study, 4 eyes of 4 patients with AZOOR were included. All patients started oral corticosteroid therapy (prednisolone) from 40mg per day. MP and SD-OCT were performed before and 2, 4, and 10 weeks after the initial treatment. Horizontal and vertical line scans through the fovea were obtained at an angle of 30°, followed by volume scans (13 horizontal B-scans). A freely available image-processing program (ImageJ, US National Institutes of Health, Bethesda, MD USA) was used to quantify the extent of disruptions of the photoreceptor inner segment (IS) ellipsoid. Disruption of IS ellipsoid border was defined as the line on the greyscale image along which IS ellipsoid reflectivity diminished by 2 standard deviations compared to the IS ellipsoid reflectivity in the unaffected retina.
Results:
Before treatment, the mean retinal sensitivity was 12.0 ± 1.3 dB, and retinal sensitivity below 5 dB or 10 dB was seen in 8.8 ± 1.8 points and 16.8 ± 3.4 points, respectively. The mean area without IS ellipsoid was 16501.5 ± 14967.5 pixels. The mean retinal sensitivity was 12.6 ± 5.8 dB at the intact IS ellipsoid locations and 4.4 ± 5.2 dB at locations of disruption (P <0.001). Two weeks after the initial treatment, the mean retinal sensitivity improved significantly (15.0 ± 0.9 dB, P=0.009), and the mean points with retinal sensitivity below 5 dB or 10 dB decreased to 0.8 ± 0.5 points and 3.5 ± 1.6 points, respectively. (P=0.003 and 0.004, respectively) Ten weeks after the initial treatment, the mean retinal sensitivity was 15.6± 2.2 dB, and the area without IS ellipsoid disappeared.
Conclusions:
This study demonstrated the relationship between microstructural abnormalities in the retina and retinal sensitivity using SD-OCT and MP. In this series, oral steroid treatment was effective to improve both photoreceptor abnormalities and retinal sensitivity in eyes with AZOOR. The combination of the MP and SD-OCT can be helpful in evaluating treatment responses.
Keywords: 688 retina •
550 imaging/image analysis: clinical •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)