Plasma, aqueous and vitreous homocysteine levels in proliferative diabetic retinopathy
- Chern Pin Lim1,
- Angela Voon Pei Loo1,
- Keat Ween Khaw1,
- Pavai Sthaneshwar2,
- Tsung Fei Khang3,
- Mohd Hassan1,
- Visvaraja Subrayan1
- 1Department of Ophthalmology, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
- 2Department of Pathology, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
- 3Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
- Correspondence to Dr Visvaraja Subrayan, Department of Ophthalmology, University of Malaya Medical Centre, Lembah Pantai, 59100 Kuala Lumpur, Malaysia;
Contributors We assure that all authors included in this paper fulfil the criteria of authorship. In addition there is no one else who fulfils the criteria that has not been included as an author. The following are each author's contribution to this manuscript: (1) CPL: design of study, data acquisition including collecting and processing blood, aqueous and vitreous samples, drafting article, final approval of manuscript (2) AVPL: design of study, data acquisition including performing the vitrectomies and sample collection, revising article, final approval of manuscript (3) KWK: analysis of data, drafting article, final approval of manuscript (4) PS: design of study, data acquisition, performed measurements and analysis of homocysteine levels, revising article, final approval of manuscript (5) TFK: analysis of data including statistical analysis, drafting article, final approval of manuscript (6) MH: design of study, securing grant, revising article, final approval of manuscript (7) VS: design of study, revising article and final approval of manuscript.
- Accepted 29 January 2012
- Published Online First 21 February 2012
Background/Aims To compare homocysteine (Hcy) concentration in the blood plasma, vitreous and aqueous of eyes with proliferative diabetic retinopathy (PDR) against control, 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 during 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 control. 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).
Conclusion The geometric mean of Hcy concentration in the blood plasma, vitreous and aqueous of the PDR group was significantly higher than control. The Hcy levels in the blood plasma and vitreous were also significantly associated in both groups. However, the blood plasma and aqueous were significantly associated only in the PDR group.
- diabetic retinopathy
- lens and zonules
- experimental and laboratory
- clinical trial
Funding This work was supported by University of Malaya Research Grant (Grant number: UMRG/RG180/10HTM).
Competing interests None.
Ethics approval The ethics approval was provided by Medical Ethics Board of the University of Malaya Medical Centre (Reference number: 756.6).
Provenance and peer review Not commissioned; externally peer reviewed.