Abstract
Purpose :
To assess whether smartphone-based optic nerve head (ONH) evaluation is equivalent to conventional digital fundus photography (CFP).
Methods :
50 eyes with glaucoma or suspected to have glaucoma were imaged with CFP (Visucam 500, Carl Zeiss Meditec, Jena, Germany) and smartphone-based fundus photography (SBFP) using the D-Eye adapter (D-EYE S.r.l., Padova, Italy) with a Galaxy S4 (Samsung Electronics, Seoul, South Korea). SBFP was performed both undilated and following dilation. CFP was performed following dilation. Both image modalities were compared in regards to evaluation of vertical cup-to-disc ratio (CDR), ISNT rule, neuroretinal rim pallor (NRP), image quality and completeness of ONH visualization. All images were pseudonymized and graded by two blinded graders. Data were analyzed descriptively.
Results :
CDR measurements on images obtained following dilation highly correlated with measurements on CFP (mean CDR on CFP=0.79, mean CDR on SBFP with dilation=0.76; r=0.76, p<0.0001), whereas CDR was underestimated on images obtained without dilation and correlated less well with CFP (mean CDR on SBFP without dilation=0.70; r=0.54, p=0.0003). Better image quality on smartphone-based fundus photographs was achieved with dilation (median = 4 vs. 3, respectively, on a scale from 0 to 5; p<0.0001). SBFP NRP evaluation on images following dilation showed a stronger correlation with evaluation on CFP (r=0.51 and r=0.30, respectively). ISNT rule evaluation was possible in 72% of images obtained without dilation and on 98% of images following dilation. Complete visualization of the ONH was possible in 46% of images without dilation and on 94% of images with dilation.
Conclusions :
Smartphone-based fundus photography for ONH evaluation is promising, however dilation is necessary to achieve results comparable to optic disc evaluation on CFP. ONH imaging with smartphones without dilation bears for example the risk of underestimating the CDR and hence overlooking a patient at risk for glaucoma.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.