Comparison of functional and morphological diagnostics in glaucoma patients and healthy subjects

To evaluate the diagnostic value of microperimetry (MP), blue-on-yellow perimetry (B/YP), confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph, HRT, III) and optical coherence tomography (OCT) in discriminating eyes with early glaucoma from healthy subjects.

Prospective examination of 22 eyes of subjects with early primary open-angle glaucoma and 24 eyes of healthy control subjects. After a complete ophthalmological examination, B/YP, MP, OCT and HRT III were determined. Morphological and functional parameters were analysed.

Mean sensitivity threshold values obtained with B/YP and MP did not show significant differences between glaucoma patients and the control group (p = 0.321 and p = 0.281). Retinal nerve fibre layer (RNFL) thickness was significantly decreased in patients with glaucoma with both HRT III and OCT (p = 0.018 and p < 0.001).

While B/YP and MP had no ability to discriminate between subjects with early glaucoma and healthy subjects, RNFL thickness measured with HRT III and OCT showed a significant difference. In early primary open-angle glaucoma, morphological changes like RNFL thickness seem to occur prior to functional defects in the visual field.