Retrobulbar Hemodynamics and Visual Field Progression in Normal Tension Glaucoma: A Long-Term Follow-Up Study

PURPOSE Vascular risk factors are important factors in the pathogenesis of glaucoma. The purpose of this research was to investigate retrobulbar hemodynamics and visual field progression in patients with normal tension glaucoma (NTG). PATIENTS AND METHODS 31 eyes of 16 patients with NTG were included in a retrospective long-term follow-up study. Colour Doppler imaging was performed at baseline to determine various CDI parameters in the different retrobulbar vessels. The rate of visual field progression was determined using the Visual Field Index (VFI) progression rate per year (in %). To be included in the analysis, patients had at least 4 visual field examinations with a follow-up of at least 2 years. RESULTS Mean follow-up was 7.6 ± 4.1 years with an average of 10 ± 5 visual field tests. The mean MD (mean defect) at baseline was -7.61 ± 7.49 dB. The overall VFI progression was -1.14 ± 1.40% per year. A statistical significant correlation between VFI progression and the RI of the NPCA and PSV of the CRA was found. CONCLUSION Long-term visual field progression may be linked to impaired retrobulbar hemodynamics in patients with NTG only to a limited degree. Interpretation of the data for an individual patient seems to be limited due to the variability of parameters.