Abstract
Purpose: :
To compare homocysteine (Hcy) concentration in the blood plasma, vitreous and aqueous of eyes of patients with proliferative diabetic retinopathy (PDR) against those in a control group, and to investigate associations between Hcy concentration in blood plasma with that of aqueous and vitreous in these two groups.
Methods: :
Blood plasma, aqueous and vitreous samples were collected at the time of combined cataract and pars plana vitrectomy from 20 eyes with PDR and 21 eyes of patients without diabetes mellitus. Hcy concentration in the samples was determined by chemiluminescent microparticle immunoassay.
Results: :
The mean Hcy concentration (± standard deviation) of blood plasma, vitreous and aqueous were 13.7± 2.2 µmol/l, 3.4±0.7 µmol/l and 1.6±0.3 µmol/l respectively in the PDR group; in the control group, they were 10.4±1.1 µmol/l, 2.6±0.9 µmol/l and 1.2±0.2 µmol/l, respectively. The estimated geometric mean of Hcy concentration of all three variables in the PDR group was about 30% higher than those in the control group. In the PDR group, Hcy concentration between the blood plasma and vitreous was significantly associated (ρ=0.71; p-value < 0.001), as was that between the blood plasma and aqueous (ρ=0.68; p-value < 0.001). In the control group, only Hcy concentration in the blood plasma and vitreous was significantly associated (ρ=0.66; p-value = 0.001); that between the plasma and aqueous was not (ρ=0.24; p-value = 0.30).
Conclusions: :
Patients with PDR had significantly higher Hcy concentration in blood plasma, vitreous and aqueous compared to those in the control group. The Hcy levels in blood plasma and vitreous were significantly associated in both groups. However, Hcy levels in blood plasma and aqueous were significantly associated only in the PDR group and not in the control group.
Keywords: diabetic retinopathy • vitreous • aqueous