Abstract
Purpose :
To evaluate the diagnostic accuracy of retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) analysis and optic nerve head (ONH) measurements using spectral-domain optical coherence tomography (SD-OCT) compared to its internal normative database.
Methods :
In this prospective cross-sectional study, patients with glaucoma or suspected glaucoma and healthy subjects were tested on Cirrus SD-OCT. Sensitivity and specificity at the 1% and 5% levels outside the normative values were calculated for the 31 parameters given by the Cirrus OCT chart on RNFL, ONH and GCC analysis.
Results :
A total of 120 randomly chosen eyes of 120 subjects were included (40 healthy eyes, 40 eyes with glaucoma and 40 eyes with suspected glaucoma). To detect the glaucomatous eyes, sensitivity ranged from 2 to 80% at the 1% level and from 15 to 82.5% at the 5% level, with rather low negative predictive values (from 48.6 to 81.4% at the 1% level). GCC parameters showed better intrinsic values than RNFL or ONH parameters (best parameter, minimal ganglion cell layer (GCL) thickness; Se = 80% at the 1% level). Specificity ranged from 86 to 100% at the 1% level and from 81 to 97% at the 5% level, with rather high positive predictive values (66.7–100%).
For detecting the suspected glaucomatous eyes, sensitivity values ranged from 0 to 42% at the 1% level and from 8 to 57% at the 5% level. RNFL parameters had higher intrinsic values than GCC and ONH parameters (best parameters, RNFL symmetry; Se = 42.9% at the 1% level). Specificity ranged from 86.1 to 100% at the 1% level and from 80.5 to 97.3% at the 5% level. Overall, the sensitivity and specificity of the global parameters were higher than those of the regional parameters.
Conclusions :
For glaucoma diagnosis, continuous analysis should be preferred instead of comparisons to normative values both at the 1% and 5% levels. The sensitivity of the comparisons to the normative database is rather low, indicating that an OCT presented as normal on the chart (reprint in green) does not exclude glaucoma. In contract, the specificity of the comparisons to the normative database is rather high, indicating that an OCT presented as abnormal on the chart (reprint in yellow or red) indicates a high probability of glaucoma.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.