Abstract
Purpose :
Detecting glaucoma in community screenings has been largely limited due to the lack of an efficacious method. We hypothesize that a portable spectral domain optical coherence tomography (SD-OCT) operated by non-professional photographers on undilated eyes can serve as a sensitive and specific screening tool to detect glaucoma.
Methods :
Given the low prevalence of glaucoma in a screening population, we conducted this prospective study in the clinic and recruited 112 adult individuals: 54 patients diagnosed with primary open angle glaucoma and 58 control subjects. Non-professional photographers captured images on undilated eyes using the Optovue iVue SD-OCT, a compact device that we could make readily portable. Three scans were collected per eye: retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and 3D optic nerve head (3D ONH). For statistical analysis, the more abnormal OCT parameter of the two eyes was selected, and these parameters were treated as categorical variables in predicting glaucoma. Positive predictive value (PPV) and negative predictive value (NPV) for each OCT parameter were calculated based on a high prevalence of glaucoma of 4%.
Results :
The following parameters exhibited high sensitivity and specificity (95% exact confidence interval or CI): GCC total thickness 76% (62-87) and 86% (74-94), RNFL average thickness 89% (77-96) and 83% (70-92), RNFL average superior hemisphere thickness 85% (72-93) and 87% (74-94), RNFL average inferior hemisphere thickness 87% (75-95) and 88% (77-96), and cup to disc vertical ratio 72% (58-83) and 94% (84-99). The PPV and NPV (95% CI) for these parameters were: GCC total thickness 18% (6-24) and 99% (96-100), RNFL average thickness 18% (7-20) and 99% (97-100), RNFL average superior hemisphere thickness 21% (8-25) and 99% (97-100), RNFL average inferior hemisphere thickness 23% (9-27) and 99% (97-100), and cup to disc vertical ratio 33% (10-45) and 99% (97-100).
Conclusions :
The Optovue iVue SD-OCT is a device that can be made portable and used by non-professional photographers on undilated eyes. The scanned images generate quantitative parameters that can predict glaucoma with relatively high sensitivity and specificity. These findings implicate the promising utility of the Optovue iVue SD-OCT in community screenings as an improved method to reliably and effectively identify individuals with glaucoma.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.