Comparison of optic nerve head analysis in patients with glaucomatous optic neuropathy between the simultaneous stereoscopic photography retinal camera (Kowa nonmyd WX3D) and the confocal scanning laser ophthalmoscope (HRT III)

Abstract

Purpose : To assess the agreement between optic nerve head (ONH) parameters in patients with primary open angle glaucoma using the confocal laser scanning ophthalmoscope Heidelberg Retina Tomograph (HRT III, Heidelberg engineering GmbH, Heidelberg, Germany) and the non-mydriatic stereoscopic retinal camera Kowa nonmyd WX3D (Kowa Company Ldt, Nagoya, Japan).

Methods : 40 eyes of 40 patients with primary open angle glaucoma were investigated according the agreement of morphometric ONH parameters assessed with both devices, HRT III and Kowa nonmyd WX3D. Vertical cup-to-disc-ratio (CDR), cup volume, rim volume, disc area and maximum cup depth were therefore compared retrospectively. Two groups were formed due to vertical cup-to-disc-ratio (CDR) assessed with HRT III as a type of gold standard. 24 eyes were included in the CDR<0.5 group and 16 eyes were included in the CDR≥0.5 group. Agreement between ONH measurements from both devices was analyzed using Bland-Altman plots and corresponding mean differences and limits of agreement (95% CI).

Results : Comparison of overall vertical CDR between HRT III and Kowa WX3D measurements showed a mean difference (limits of agreement) of -0.0587 (-0.3604 to 0.2429). Mean difference in vertical CDR was -0.1400 (-0.3352 to 0.0553) for the CDR<0.5 group and 0.0631 (-0.2138 to 0.3401) for the CDR≥0.5 group. So Kowa WX3D tended to show slightly lower CDR in comparison to HRT III in the CDR<0.5 group and tended to show slightly higher CDR in CDR≥0.5 group.

Conclusions : Kowa nonmyd WX3D and HRT III showed a good agreement between ONH parameters like vertical CDR with regard to mean bias and limits of agreement in patients with glaucomatous optic neuropathy.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.