Abstract
Purpose :
To determine and quantify central and temporal retinal and choroidal vascular abnormalities using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA) in patients with sickle cell disease (SCD).
Methods :
Forty-six eyes of 23 consecutive patients with electrophoretic confirmation of SCD were analyzed. Centrally and temporally centered SD-OCT (Spectralis, Heidelberg Engineering) and OCTA (Avanti RTVue XR; Optovue Inc) were performed. An age and sex-matched control group of healthy patients was also recruited. SD-OCT scanning protocol included 31 B-scans, spaced 240 microns apart and covering a 30° x 25° area. SCD eyes were divided into 2 groups based on the presence of visible macular thinning areas, defined as thinning associated with loss of definition of inner retinal layers on OCT scans and identified as blue patchy areas on retinal thickness color-coded map.
Results :
Nineteen out of 46 eyes (41.3%) were noted to have patchy areas of macular thinning on SD-OCT. In comparison to healthy controls, OCTA in SCD subjects showed foveal avascular zone enlargement in both the superficial (SCP) and the deep (DCP) capillary plexus (p< 0.0001, p=0.0171).
In SCD eyes, vessel density was significantly lower in the DCP (p< 0.0001), both in central and temporal scans. Central SCP and DCP flow area (p= 0.0012, p= 0.0003) and temporal DCP flow area were reduced (p= 0.0255) in SCD patients. In comparison to controls, the flow area in non-patchy eyes was diminished both in SCP and DCP but only in the central scans (p=0.0003, p=0.0004), while the flow area in patchy eyes was reduced only in the DCP both centrally and temporally (p=0.0022, p=0.0073). Choriocapillaris abnormalities were significant in both areas in SCD subjects (p< 0.0001, p= 0.0129).
Conclusions :
In our study, SCD microangiopathy involved both SCP, DCP and choriocapillaris. In comparison to controls, patchy eyes showed deep vascular abnormalities involving both central and temporal macula. Considering that perfusion defects in non-patchy eyes were limited to the central macula, deep temporal retinal hypoperfusion could cause patchy areas of macular thinning that are frequently observed temporal to the fovea in SCD eyes. Possible further studies could correlate SD-OCT retinal segmentation with OCTA findings.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.