Purpose
To investigate the changes in the central retinal vessel diameter in bilateral glaucoma suspect patients with unilateral glaucomatous conversion.
Methods
This study included 21 patients who had been diagnosed with bilateral glaucoma suspect initially and showed asymmetric glaucomatous conversion during the follow-up period of more than 3 years. Conversion to glaucoma was determined by development of new retinal nerve fiber layer (RNFL) defects on red-free RNFL photographs or occurrence of a glaucomatous visual defect. Central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured from the fundus photographs taken at baseline and at the time of detection of glaucomatous conversion.
Results
The mean CRAE of the converted eyes was significantly narrower than that of non-converted eyes at baseline (178.40 ± 16.73 μm vs. 188.84 ± 19.97 μm, p=0.003), but no significant inter-eye difference was observed in the mean CRVE (p=0.901). Both the converted (p=0.022) and the non-converted eyes (p= 0.001) showed significant changes in CRAE between the baseline measurements and those taken when glaucomatous conversion was detected. The mean CRAE of the converted eyes was also narrower than that of non-converted eyes at the time of detecting glaucomatous conversion (168.55 ± 20.54 μm vs. 180.59 ± 19.67 μm, p=0.021).
Conclusions
The differences of CRAE between the converted and the non-converted eyes preceded the development of a new RNFL defect on red-free photographs or a glaucomatous visual field defect. These findings suggest that measurement of retinal arteriolar diameter may help us detect the development of glaucoma early.