Xiu-Fen Yang

Relationship of retinal vascular calibre and diabetic retinopathy in Chinese patients with type 2 diabetes mellitus: the Desheng Diabetic Eye Study

Aims To describe the relationship of retinal arteriolar and venular calibre with diabetic retinopathy (DR) and related risk factors, including glucose levels and other biomarkers in a Chinese population with type 2 diabetes mellitus (T2DM). Methods A cross-sectional study. Patients with T2DM were recruited from a local community in urban Beijing. Seven fields 30° colour fundus photographs were taken and examined for the presence and severity of DR using a standardised grading system. Retinal vascular calibres were measured and expressed as average central retinal arteriolar and venular equivalent using a computer-based program. Results A total of 1340 patients with T2DM were included for analysis. Of these, 472 (35.22%) had DR. Wider retinal venular calibre, but not arteriolar calibre, was associated with increasing glucose and glycosylated haemoglobin A1c levels (p<0.006) and dyslipidaemia (p for trend <0.05). After adjusting for possible covariates, the higher quartile of retinal venular calibre was associated with higher prevalence of any DR (OR 2, 95% CI 1.36 to 2.95). Venular calibre increased from 224.33 μm in those without retinopathy to 231.21 μm in those with mild, 241.01 μm in those with moderate and 235.65 μm in those with severe retinopathy (p for trend <0.001). Arteriolar calibre was not associated with DR. Conclusions In the current study, wider venular calibre, but not arteriolar calibre, was shown to be associated with development and increased severity of DR independently from other risk factors in a Chinese diabetic population.

Association of C(-106)T Polymorphism in Aldose Reductase Gene with Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes Mellitus

OBJECTIVE To identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM). METHODS From November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed. RESULTS A total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09). CONCLUSIONS Microalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.

C-reactive protein and diabetic retinopathy in Chinese patients with type 2 diabetes mellitus

AIM To investigate the relationship between C-reactive protein (CRP) and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM). METHODS Community-based observational cohort study. There were 1131 participants recruited from November 2009 to September 2011 in Desheng community in urban Beijing. Patients diagnosed T2DM were recruited and underwent a standardized evaluation consisting of a questionnaire, ocular and anthropometric examinations and laboratory investigation. The presence and severity of DR were assessed by seven fields 30° color fundus photographs. Subjects were then classified into groups with no DR, any DR, or vision-threatening DR. CRP was analyzed from serum of study subjects. RESULTS A total of 1007 patients with T2DM were included for analysis, including 408 (40.5%) men and 599 (59.5%) women. The median CRP level was 1.5 mg/L for women and 1.1 mg/L for men (P=0.004, OR 0.37, 95% CI 0.18-0.74). After adjusting for possible covariates, higher levels of CRP were associated with lower prevalence of any DR (P=0.02, OR 0.55, 95% CI 0.35-0.89), but not associated with vision-threatening DR (P=0.62, OR 0.78, 95% CI 0.28-2.14). After stratification by sex, the inverse association between CRP and DR was found to be statistically significant in men (P=0.006, OR 0.35, 95% CI 0.16-0.73), but not in women (P=0.58, OR 0.88, 95% CI 0.29-1.16). CONCLUSION The data drawn from a Chinese population with T2DM suggest that increasing CRP levels may be inversely associated with development of DR.

The diurnal variation pattern of choroidal thickness in macular region of young healthy female individuals using spectral domain optical coherence tomography.

AIM To investigate the pattern of diurnal variations of choroidal thickness of macular region of healthyindividuals. METHODS A prospective study of 32 healthy female subjects was conducted. Each subject underwent 1) a questionnaire on daily schedule, 2) the Pittsburgh Sleep Quality Index questionnaire (PSQI), and 3) ocular examinations including an eye dominance test, fundus photography, and sequential optical coherence tomography (OCT) imaging, on two separate days at five fixed 3h time intervals. Choroidal thickness was measured by two masked graders. RESULTS A significant diurnal variation of choriodal thickness at fovea (P<0.001), at 500 µm nasal (P<0.001), temporal to fovea (P=0.01) or 1500 µm nasal to fovea (P=0.001) was observed. The median choroidal thickness peaked at 11:00 at fovea (P=0.01), at 500 µm nasal (P=0.009) and temporal (P=0.03) to fovea. The median amplitude of foveal choroidal thickness was 20.5 µm (13, 31) and 20.0 µm (12.5, 28.2) for the first and second series of measurements, respectively. The greater amplitude of foveal choroidal thickness was associated with thickner initial foveal choroidal thickness [0.05 (0.03, 0.08), P=0.01], dominant eye [10.51 (4.02, 14.60), P=0.04] in the multivariate linear regression. CONCLUSION Our data show a significant diurnal variation of the choroidal thickness at fovea, at 500 µm nasal and temporal to fovea and 1500 µm nasal to fovea. Thicker initial foveal choroidal thickness and being dominant eye may influence the amplitude of foveal choroidal thickness.

Measurement of macular pigment optical density among healthy Chinese people and patients with early-stage age-related macular degeneration

AIM To measure the macular pigment optical density (MPOD) in healthy Chinese people and patients with early age-related macular degeneration (AMD). METHODS Cross-sectional population based study. Demographic and lifestyle characteristics were ascertained by questionnaire. A food frequency questionnaire was completed for all participants. Participants underwent general physical and ophthalmic examinations and MPOD was measured by heterochromatic flicker photometry. Foveal architecture was measured by optical coherence tomography. RESULTS MPOD of 225 participants (122 healthy and 103 early AMD) was 0.48±0.18. Patients with early AMD (0.52±0.19) tended to have higher MPOD levels than healthy people (0.47±0.17), but the difference was not statistically significant (P=0.06). Participants with carrot or corn oil intake every week tended to have higher levels of MPOD (P=0.002 and 0.008 respectively) while those with corn intake had relatively lower level of MPOD (P=0.01). MPOD increased with the center foveal thickness (P=0.01). CONCLUSION Our findings show that there is no statistically significant association between MPOD and early AMD in the studied population. MPOD is related to center foveal thickness and diets would influence MPOD levels.

Association of glutathione S-transferase pi isoform single-nucleotide polymorphisms with exudative age-related macular degeneration in a Chinese population.

Purpose: To investigate the association between single-nucleotide polymorphisms in the pi isoform of glutathione S-transferase (GSTP1) gene and the risk of exudative age-related macular degeneration (AMD) in a Chinese case–control cohort. Methods: A total of 131 Chinese patients with exudative AMD and 138 control individuals were recruited. Genomic DNA was extracted from venous blood leukocytes. Two common nonsynonymous single-nucleotide polymorphisms in GSTP1 (rs1695 and rs1138272) were genotyped by polymerase chain reaction followed by allele-specific restriction enzyme digestion and direct sequencing. Results: Significant association with exudative AMD was detected for single-nucleotide polymorphism, rs1695 (P = 0.019). The risk G allele frequencies were 21.8% in AMD patients and 12.7% in control subjects (P = 0.007). Compared with the wild-type AA genotype, odds ratio for the risk of AMD was 1.91 (95% confidence interval, 1.09–3.35) for the heterozygous AG genotype and 2.52 (95% confidence interval, 0.6–10.61) for the homozygous GG genotype. In contrast, rs1138272 was not associated with exudative AMD (P = 1.00). The risk G allele frequencies of rs1138272 were 0.4% in AMD patients and 0.4% in control subjects (P = 1.00). Conclusion: Our data suggest that the GSTP1 variant rs1695 moderately increases the risk of exudative AMD. The variant rs1138272 was rare and was not associated with exudative AMD in this Chinese cohort.