Abstract
Purpose:
To investigate the effect of a prostaglandin (PG) analogue on optic nerve head (ONH) blood flow in eyes with preperimetric (PPG) glaucoma over a 12-month treatment period.
Methods:
In this prospective multicenter study, all patients were treated with a topical prostaglandin (PG) analogue. Diagnosis was performed by glaucoma specialists between August 2012 and April 2014. We collected general ophthalmological examination data, and obtained a range of ONH blood flow data with laser speckle flowgraphy (LSFG) in 136 eyes of 136 PPG patients (mean 53.8 ± 14.3 years old) treated with Tafulprost for up to 1 year. Changes in ONH mean blur rate (MBR), a parameter of LSFG that represents relative blood flow, before and 90-120 minutes after the treatment were determined upon enrollment. We defined the patients in the upper quartiles of percentage changes in MBR as high-responders (HRs: 31 eyes) and patients in the lower quartile as low-responders (LRs: 30 eyes). Finally, we compared the prospectively collected follow-up data between the two groups.
Results:
There were significantly greater changes in ONH MBR in the HRs than in the LRs both at 4 months and 12 months after the start of treatment (4 months: HRs 5.13 ± 7.87%, LRs -1.52 ± 7.60%, p < 0.001; 12 months: HRs 9.50 ± 6.58%, LRs -2.69 ± 7.95%, p < 0.001). There were no significant differences in intraocular pressure, mean arterial blood pressure, or ocular perfusion pressure between the two study groups. In all patients, the ONH MBR in the pre-instillation period was negatively correlated with changes in ONH MBR at both 4 months and 12 months after the start of treatment (4 months: r = -0.22, p = 0.02; 12 months: r = -0.41, p < 0.001).
Conclusions:
HRs in PPG patients showed a steady increase in ONH blood flow over a twelve-month period after the start of PG analogue treatment. Furthermore, our results suggested that patients with lower initial ONH blood flow had a higher possibility to increase ONH blood flow through treatment.