NCOG-15. A PILOT STUDY ON RETINAL FEATURES AND COGNITIVE FUNCTION IN PATIENTS WITH LOW GRADE GLIOMAS

Abstract

Abstract BACKGROUND Retinal structure and vascular changes are used as biomarkers for preclinical Alzheimer disease. We conducted a cohort study to evaluate the feasibility of obtaining these data in patients with low-grade gliomas (LGGs) who completed chemoradiation therapy with and without self or family reported cognitive concerns. METHODS Optical coherence tomography (OCT) and angiography (OCTA, OptoVue, Inc.) images were obtained from 6 LGG patients and 2 healthy controls using 4.5 x 4.5 mm peripapillary and 6x6 mm macular scan patterns. We measured OCTA parameters including radial peripapillary capillary density for the peri-optic disc region, whole macular density, and foveal avascular zone (FAZ). RESULTS We analyzed two eyes of two control subjects, an LGG patient with normal cognition, and 5 LGG patients with cognitive impairment (mean age 45 years, range of 3 months to 10 years after chemoradiation). Both controls had normal eye exams. Average retinal nerve fiber layer thickness was thinner in patients with and without cognitive dysfunction (104 um and 106 um, respectively) than controls (123 um). A similar pattern was seen in macula thickness (283 um and 290 um vs. 325 um). The average peripapillary vessel densities were lower in patients with and without cognitive dysfunction (47.7% and 48.3%, respectively) than controls (51.9%). The whole macular vessel densities were similar in three groups (46.7 %, 48.0%, and 48.0 %). Average FAZs were larger in patients with cognitive dysfunction (0.254 mm2) than the patient with normal cognition (0.204 mm2) and controls (0.226 mm2). CONCLUSIONS Retinal architecture and microvascular changes measured by OCT/OCTA is feasible in LGG patients after chemoradiation. A larger prospective study is needed to investigate the role of OCT/OCTA in detecting peripapillary and perifoveal changes in brain tumor patients with treatment-associated cognitive dysfunction.