Protein Z Plasma Levels are Not Elevated in Patients with Non-Arteritic
Anterior Ischemic Optic Neuropathy
, *, Taxiarchis L Felekis1, Spiridon Gorezis2, Lefkothea Dova3, Eleni Dokou3, Georgios Vartholomatos2, Miltiadis Aspiotis1, Nikolaos I Kolaitis2
1 University Eye Clinic of Ioannina, Greece
2 Epirus Vision Center, Ioannina, Greece
3 Haematology Laboratory of the University Hospital of Ioannina, Greece
Background: Protein Z is a glycoprotein that acts as a co-factor for the inhibition of activated coagulation factor X. Protein Z circulating in abnormal levels has been associated with increased risk for acute ischemic events. Non-arteritic Anterior Ischemic Optic Neuropathy (N-AION) is caused by acute ischemic infarction of the optic nerve head, supplied by the posterior ciliary arteries.
Objectives: The aim was to investigate whether there is an association between N-AION and plasma protein Z levels.
Patients and Methods: Twenty-six cases of confirmed N-AION and fifty-two controls were included in the study group. Protein Z was estimated in thawed citrate plasma on both N-AION cases and controls by an enzyme immunoassay. The imprecision of the estimation was satisfactory (CV = 4, 6%).
Results: The controls’ protein Z values distributed within a range 340 to 4200 ng/ml (median = 1420, mean = 1673, SD = 1040 ng/ml). Patients’ protein Z values distributed within a range 420 to 3600 ng/ml (median = 1030, mean = 1520, SD = 939 ng/ml). There was no statistical difference between the two distributions (Independent t-test, p=0.529).
Conclusion: In our study, protein Z levels are not implicated in the pathogenesis of non-arteritic anterior ischemic optic neuropathy (N-AION).
Keywords: Protein Z, Non-arteritic anterior ischemic optic neuropathy.
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
* Address correspondence to this author at the University Eye Clinic of
Ioannina, Kosti Palama 1, Anatoli-Ioannina 45500, Greece; Tel: 0030-
2651067689; Fax: 0030-2651022928; E-mail: email@example.com