Purpose
Developing a non-invasive measure of posterior segment ocular inflammation may provide a new way to assess disease activity and treatment response. We developed an algorithm to measure vitreous hyper-reflective foci (VHRF) from standard 3D OCT images in an unbiased manner. This algorithm was applied to OCT scans from patients with uveitis, diabetes, and diabetic macular edema to determine whether VHRF score may serve as a non-invasive measure of inflammation.
Methods
We retrospectively analyzed the OCT scans from 117 patients that were seen at the University of Michigan. Patients with established uveitis of varying vitreous cell grade were compared to controls. Additionally, patients with DME, and diabetics without signs of retinopathy were compared to controls. An algorithm was developed which enhanced the vitreous imaging from OCT, performed automated quantification of VHRF, and calculated a VHRF score representing foci per vitreous volume for each scan (Figure 1). This score was compared between control eyes, and eyes with uveitis and diabetic retinopathy.
Results
VHRF scores increased with higher clinically graded degree of uveitis (p=0.029), suggesting VHRF is associated with inflammation. Further, VHRF scores were increased in patients with DME compared to control patients (p=0.012) and to patients with diabetes without retinopathy (p=0.005). Vitreoretinal separation appeared to combine with DME to further increase VHRF score.
Conclusions
VHRF scores may be obtained from OCT images that include the vitreous, and may provide a rapid and non-invasive clinical correlate for ocular inflammation. Higher VHRF scores in patients with uveitis and DME warrant further population based and longitudinal studies to help determine the value of VHRF score in initiating therapeutic intervention and monitoring of treatment response.