Increased erythrocyte aggregation in patients with primary open angle glaucoma

Abstract

Background

The rationale of this study is to determine alterations in blood rheology (erythrocyte aggregation and deformability) and relationship between structural measurements obtained from optical coherence tomography (OCT) in different stages of primary open angle glaucoma (POAG).

Methods

This prospective controlled study comprised 23 POAG patients (glaucoma group) and 23 age‐ and sex‐matched healthy subjects (control group). Elongation index (EI), which is the indicator of erythrocyte deformability and erythrocyte aggregation was measured using an ektacytometer. Optic nerve head (ONH) morphology and peripapillary retinal nerve fibre layer (RNFL) thickness were evaluated using a spectral domain (SD) OCT.

Results

There were no significant differences between the groups regarding the elongation index values (p > 0.05). On the other hand, erythrocyte aggregation amplitude (AMP) and mean corpuscular haemoglobin concentration (MCHC) were significantly higher in the glaucoma group than in the control group (p = 0.015, p = 0.003 respectively). A significant correlation was also found between the elongation index and retinal nerve fibre layer (average and superior) thickness (p < 0.05) in patients with late glaucoma.

Conclusions

In patients with POAG, erythrocyte aggregation appears to be higher. It can be speculated that higher erythrocyte aggregation and deformability may be involved in the pathogenesis of glaucoma by affecting microperfusion of the optic nerve head and retina. Modification of rheological parameters in patients with glaucoma may be considered as an adjuvant future therapy in glaucoma management, whereas further studies in larger groups are needed.

Key words:

• erythrocyte aggregation
• optic nerve head
• optical coherence tomography
• primary open angle glaucoma
• red blood cell deformability

Acknowledgements

The abstract of this study was presented as a poster in the Joint Meeting of the Federation of European Physiological Societies and the Baltic Physiological Societies, Kaunas, Lithuania, August 26‐29, 2015.