Macular thickness assessment in patients with primary open-angle glaucoma and its correlation with central visual field

Abstract

Background Glaucoma is a multifactorial chronic optic neuropathy characterized by typical optic nerve morphological changes and alterations of the visual field (VF). Delayed detection and treatment of glaucoma might result in irreversible blindness. Structural damage precedes the functional damage. Objective The objective of this study was to correlate between macular thickness (MT) affection and central VF changes in patients with primary open-angle glaucoma (POAG). Patients and methods This is a prospective cross-sectional observational study that included 51 eyes diagnosed with POAG. They were evaluated by spectral domain optical coherence tomography, which was compared with several VF parameters, including mean deviation and loss variance. Results A significant correlation was found between VF parameters and decrease in MT (mean deviation: r=−0.506; P=0.000, loss variance: r=−0.492; P=0.000). There was also a significant correlation between thinning of the superior temporal and inferior temporal retinal nerve fiber layer and the decrease of the superior and inferior MT, correspondingly (P<0.001). Conclusion Measurements of the retinal thickness in the macula may be an additional tool for early detection of structural changes and its correlation with functional defects. Measuring the MT by spectral domain optical coherence tomography and using VF 10-2 degrees should be a standard technique in evaluation and follow-up of patients with primary open-angle glaucoma, although the VF is a time-consuming technique.

Keywords

• macula
• primary open-angle glaucoma
• optical coherence tomography
• retinal nerve fiber layer
• visual field