Abstract
Purpose :
To evaluate microcirculation of the central retina in sickle cell retinopathy (SCR) patients with Optical Coherence Tomography Angiography (OCTA), and to assess the possible correlation between the degree of central retinal capillary nonperfusion and the stage of the peripheral SCR.
Methods :
This is a retrospective study of OCTA image in patients with SCR. Clinical data including age, sex, visual acuity, associated systemic vascular disease, type of SCR, stage of peripheral SCR and history of peripheral laser were obtained. Split Spectrum Amplitude Decorrelation Angiography (SSADA) based OCTA images were analyzed with AngioAnalytical software. Areas of flow and non-flow, and vessel density were calculated in the central 6x6mm square of retina.
Results :
27 eyes of 15 patients were included in this study. There were 8 males and 8 females. Mean age was 38 (23 to 67). Mean visual acuity was 20/25 (20/15 to 20/60). SS disease was found in 10 patients, SC in 4 patients, and Sickle cell-beta thalassemia in 1 patient. Stage 3 was found in 14 eyes, and 11 of 14 stage 3 eyes had history of previous laser photocoagulation. Severe capillary non-perfusion (CNP) was found in 2 eyes with non-flow area greater than 10 mm^2 in the central retina in the superficial retinal slab (SRS). Mean vessel density was 40.9% at SRS and 40.7% at deep retinal slab (DRS). 4 eyes had moderate CNP with non-flow area between 5 to 10mm^2 in the SRS. Mean vessel density was 44.0% at SRS and 49.3% at DRS. 21 eyes had mild CNP with non-flow area smaller than 5mm^2 in both retinal slabs. Mean vessel density was 53.1% at SRS and 54.2% respectively at DRS.
Conclusions :
Every eye in this study showed some degree of CNP in the central retina. There were 2 eyes imaged from a sickle cell-beta thalassemia patient that showed significant CNP [10.343 mm^2 in 1 eye (severe CNP) and 9.793 mm^2 in 1 eye (moderate CNP)]. Other than this patient the degree of central retinal CNP was not correlated to the type of SCR or the stage of peripheral SCR. Most of the CNP occurred at the parafoveal area, predominantly on the temporal side. OCTA is a powerful new technology to assess the otherwise undetectable microvascular change of the central retina in SCR patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.