Prospective evaluation of optical coherence tomography for disease detection in the Casey mobile eye clinic

Abstract

This study was designed to evaluate iVue Spectral-domain optical coherence tomography (SD-OCT) effectiveness in screening for eye disease compared to clinical examination. Subjects were recruited from the Casey Eye Community Outreach Program Mobile Clinic during its routinely scheduled outreach clinics to indigent, underserved populations throughout Oregon. Macular optical coherence tomography interpretation and automated optical coherence tomography analysis were compared to the clinical examination, with specific attention to findings indicative of retinal abnormalities, risks for glaucoma, and narrow angles. As a result, a total of 114 subjects were included in this study. In diabetics, optical coherence tomography and clinical exam were in fair agreement (kappa = 0.39), with 22% of eyes having abnormal findings on macular optical coherence tomography and 26% of eyes having diabetic retinopathy or diabetic macular edema on fundus exam. In non-diabetics, optical coherence tomography and clinical exam were in fair agreement (kappa = 0.28), with 11% of eyes having abnormal findings on macular optical coherence tomography and 9% on fundus exam. Using optical coherence tomography ganglion cell complex and retinal nerve fiber layer analysis, 18% of eyes were found to be glaucoma suspects, whereas clinical exam of cup-to-disc ratio detected 8% and intraocular pressure 5%. Agreements between optical coherence tomography and other methods were poor (kappa < 0.11) for glaucoma suspect. Anterior segment optical coherence tomography of the angle found 8% of eyes to have occludable angles, whereas slit lamp and gonioscopy found 5% of eyes to have narrow angles, with moderate agreement (kappa = 0.57). In summary, optical coherence tomography detected additional retinal abnormalities, glaucoma suspects, and narrow angles compared to clinical exam alone and may serve as a useful adjunct to the clinical exam in screening for eye disease in a low-risk, medically underserved, ethnically diverse population.