Diagnostic Capacity and Correlation of Optic Nerve Colorimetry with Structural Parameters in Primary Open-Angle Glaucoma

Abstract

Précis: The discriminant function of glaucoma, obtained by the Laguna ONhE colorimetric program, significantly correlates with the BMO-MRW. Furthermore, the diagnostic capacity was inferior to other structural tests in POAG patients.

Purpose: To evaluate the diagnostic capability for glaucoma and the correlation between peripapillary and macular parameters using spectral domain optical coherence tomography (SD-OCT) and optic nerve head hemoglobin (OHN Hb) levels assessed by the Laguna ONhE® software using colorimetric analysis.

Methods: This cross-sectional study included 112 eyes from 112 primary open-angle glaucoma (POAG) patients and 112 eyes from 112 healthy controls. The peripapillary analysis included standard peripapillary retinal nerve fiber layer (pRNFL), Bruch’s membrane opening-minimum ring width (BMO-MRW), and peripapillary RNFL thickness measured with the Glaucoma Module Premium Edition program (RNFLT). The macular analysis assessed the ganglion cell layer (GCL), inner plexiform layer (IPL), macular RNFL (mRNFL), total retina, ganglion cell complex (GCC), and the GCL-IPL complex. The Laguna ONhE program evaluated ONH Hb levels and the glaucoma discriminant function (GDF). Pearson correlation was used to analyze the relationships between variables, and the area under the curve (AUC) was calculated.

Results: Significant differences in AUC were found between GDF (0.80) and RNFLT global (G) (0.91), BMO-MRW G (0.89), and outer-temporal GCL (0.88). BMO-MRW showed the strongest correlation with the Laguna ONhE parameters (r from 0.271 to 0.682). Additionally, a significant correlation was observed between the temporal-inferior sector of ONH Hb and the inferior macular sector (r=0.40–0.56 for GCL-IPL) (P<0.05 for all).

Conclusions: GDF demonstrated lower diagnostic capacity compared to other structural tests. BMO-MRW showed the strongest correlation with the Laguna ONhE parameters, and a significant relationship was identified between the temporal-inferior sector ONH Hb and the inferior macular region.