Peripapillary Blood Flow And β-Zone Parapapillary Atrophy in Primary Open-Angle Glaucoma

Abstract

 

Purpose:

 

To Evaluate peripapillary blood flow in patients with Primary Open-Angle Glaucoma (POAG) with and without β-Zone parapapillary atrophy (PPA) using the Retinal Functional Imager (RFI).

 

Methods:

 

Patients diagnosed with POAG as well as normal control subjects were prospectively imaged with the RFI. Arterial and venous blood flow velocities in the peripapillary area were evaluated in 73 eyes of 44 patients. Patients were divided into two groups based on the presence or absence of β-Zone PPA. β-Zone PPA was defined as a central zone of atrophy bordering the scleral ring characterized by retinal transparency with visible sclera and chorioretinal vessels. In order to normalize the severity of β-Zone PPA, patients were categorized into groups based on the size of PPA as a percentage of total disc area. Retinal nerve fiber layer (RNFL) thickness was measured using spectral domain optical coherence tomography (OCT). An ANOVA test was used for statistical analysis.

 

Results:

 

The difference in average arterial and venous blood flow was not statistically significant between eyes with and without PPA (p= 0.68 and 0.65 respectively). Although there was a small increase in arterial and venous blood velocity as β-Zone PPA increased (Graph 1), this difference was not statistically significant (p=.88, p=.47). POAG patients with PPA had significantly thinner peripapillary RNLF than those without PPA (p=0.002).

 

Conclusions:

 

Although the RNFL was thinner in patients with PPA, there was no significant difference in velocities among POAG patients with or without β-Zone PPA. While β-Zone PPA has been suggested as an indicator for a faster progression of glaucoma, we did not find an association between β-Zone PPA and retinal perfusion. There was a small increase in arterial and venous velocity as β-Zone PPA increased.  

 

Keywords: blood supply • optic disc • imaging/image analysis: non-clinical