Background: At this time little information is available about the relationship between glaucomatous visual field defects and impaired blood flow in the optic nerve head. The purpose of this study was to examine blood flow of the juxtapapillary retina and the rim area of the optic nerve head in primary open-angle glaucoma with a borderline visual defect.
Methods: Juxtapapillary retinal and neuroretinal rim area blood flow was measured by scanning laser Doppler flowmetry (SLDF). The visual field was evaluated by static perimetry (Octopus-G1). The optic nerve head was assessed on 15 degrees color stereo photographs. We examined 116 eyes of 91 patients with POAG with controlled IOP and 66 eyes of 44 healthy individuals. The POAG group was divided into eyes with a mean defect lower than 2 dB (POAG group I) and in eyes with a mean defect equal to or greater than 2 dB (POAG group II). The mean age of POAG group I and POAG group II was 55 +/- 11 years and 57 +/- 10 years, respectively. The mean age of the control group was 45 +/- 15 years. The eyes of POAG group I had an average C/D ratio of 0.71 +/- 0.18 with an average mean defect of the visual field of 0.97 +/- 0.68 dB; the eyes of POAG group II had an average C/D ratio of 0.80 +/- 0.17 with an average mean defect of the visual field of 8.2 +/- 6.0 dB. The intraocular pressure on the day of measurement in POAG group I was 18.2 +/- 3.7 mmHg, in POAG group II 17.6 +/- 4.0 mmHg, and in the control group 15.1 +/- 2.5 mmHg. For statistical analysis, age-matched groups of 32 normal eyes of 32 subjects (mean age 52 +/- 10 years) were compared to 18 glaucomatous eyes of 18 patients (POAG group I, mean age 55 +/- 11 years) and 59 glaucomatous eyes of 59 patients (POAG group II, mean age 55 +/- 10 years).
Results: In the eyes of POAG group I and POAG group II, both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area "flow" POAG group I -65%, POAG group II -66%; juxtapapillary retina "flow" POAG group I -52%, POAG group II -44%. All eyes of the POAG group I (MD < 2 dB) and 56 of 61 eyes of the POAG group II (MD > = 2 dB) showed a retinal perfusion lower than the 90% percentile of normal blood flow. We found no correlation between reduction of juxtapapillary or papillary blood flow and mean defect in POAG eyes.
Conclusion: Glaucomatous eyes with no defects or borderline visual field defects as well as glaucomatous eyes in an advanced disease stage show significantly decreased optic nerve head and juxtapapillary retinal capillary blood flow.