Abstract
Purpose :
The nature of hyperreflective foci (HRF) found on spectral domain optical coherence tomography (SD-OCT) remains uncertain. In a retrospective study, SD-OCT was utilized in conjunction with optical coherence tomography angiography (OCTA) to demonstrate the relationship between retinal vascular alterations and retinal HRF in patients with nonproliferative diabetic retinopathy (NPDR) with and without macular edema.
Methods :
A retrospective review of 30 eyes diagnosed with NPDR from 15 patients was performed, evaluating SD-OCT and OCTA (AngioPlex, Zeiss Meditec, Inc., Dublin, California) for features of HRF.
Results :
30 eyes with NPDR were examined clinically and with SD-OCT as well as OCTA. Of the 30 eyes, 24 (81%) had best corrected visual acuity of 20/40 or better. When evaluating the degree of NPDR (n=30 eyes), 6(20%) had mild NPDR, 5(17%) had moderate NPDR and 19(63%) had severe NPDR. 8(27%) had macular edema. 24(83%) had HRF present on SD-OCT. All HRF were located within the inner retinal layers on SD-OCT. Of the 24 eyes with HRF on SD-OCT, 18(75%) were found to have HRF located in close proximity to retinal vasculature in an area of decreased capillary density on corresponding OCTA analysis. Areas of decreased capillary density were more prominent in the deep capillary plexus than in the superficial capillary plexus but were present in both regions. 7(88%) of the 8 eyes with macular edema had HRF present on SD-OCT. Of the 7 eyes with macular edema also found to have HRF, 2(29%) had HRF in close proximity to retinal vasculature in areas of decreased capillary density. In contrast, of the 17 eyes without macular edema found to have HRF, 16(94%) had HRF in close proximity to retinal vasculature in areas of decreased capillary density.
Conclusions :
HRF on SD-OCT are frequently found in close proximity to retinal vessels in areas of decreased capillary density detected by OCTA, especially at the level of the deep capillary plexus. This finding suggests that the early vascular compromise in diabetic retina contributes to HRF formation. Therefore, it is conceivable to conclude that, in addition to the inflammatory pathogenesis previously proposed, local retinal ischemia is a contributing factor to the process of HRF development in diabetic retinopathy.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.