Abstract
Purpose :
To evaluate the measurement of the hypotenuse of the vertical optic nerve head cupping (HVOC) with the enhanced depth imaging (EDI) mode of the spectral domain optic coherence tomography (SD-OCT) as a novel structural parameter for glaucoma diagnosis.
Methods :
We conducted a prospective, transversal study with patients diagnosed with glaucoma and controls. Patients underwent SD-OCT evaluating the mean retinal nerve fiber layer thickness (RNFL) and the HVOC, which one leg of the triangle represented the depth and the other the length of the cupping. Patients also underwent color pictures and standard automated perimetry (SAP). The evaluation was performed in 156 eyes (83 patients) that were divided in 3 groups: 1-MD<-7DB, 2-MD>-7DB and 3-patients without glaucoma. The evaluation using the receiver operating characteristic (ROC) curve excluded eyes with the vertical diameter of the optic nerve >2.0 and <1.5.
Results :
The mean SD-OCT RNFL values were: group 1 (56 eyes): 62.5µm, group 2 (74 eyes) 83.8µm and group 3 (34 eyes) 98.7µm (p<0.0001 and r=-0.66). The means of the MD were: group 1: -16.72 DB, group 2: -2.70 DB and group 3: -1.49 DB( p<0.001 and r=-0.81). The correlation of the SD-OCT RNFL and the SAP was statistically significant (p<0.0001 e r=0.681). The correlation between the HVOC and the MD was Spearman rho= -.465 e Pearson= -.511, and with the RNFL was Spearman rho= -.624, Pearson =-.634 (n=120). The areas under the curve (AUC) of the ROC curve evaluating the HVOC were: for MD< -3DB as positives cases= 0.755 (0.664-0.845), MD < -6DB= 0,77 (0.678-0.862) and MD < -12DB= 0.798 (0.705-0.890). The ROC curves of the RNFL were compared with the HVOC using DeLong test and there was no statistically significant difference. For positive cases determined as MD< -12DB they had a borderline difference (p=0.06).
Conclusions :
In our study, we found a structural-functional correlation of the HVOC with the MD of the SAP as well as with the RNFL. The AUC of the ROC curves of HOVC were comparable with those of the RNFL. The HOVC has a potential to be used as an additional optic nerve head parameter of the multimodal structural evaluation of glaucoma.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.