Characteristics of macular microvasculature before and after idiopathic macular hole surgery.

AIM: To evaluate the macular microvasculature before and after surgery for idiopathic macular hole (MH) and the association of preoperative vascular parameters with postoperative recovery of visual acuity and configuration. METHODS: Twenty eyes from 20 patients with idiopathic MH were enrolled. Optical coherence tomography angiography (OCTA) images were obtained before, 2wk, 1, and 3mo after vitrectomy with internal limiting membrane peeling. Preoperative foveal avascular zone (FAZ) area and perimeter and regional vessel density (VD) in both layers were compared according to the 3-month best-corrected visual acuity (BCVA). RESULTS: The BCVA improved from 0.98±0.59 (logMAR, Snellen 20/200) preoperatively to 0.30±0.25 (Snellen 20/40) at 3mo postoperatively. The preoperative deep VD was smaller and the FAZ perimeter was larger in the 3-month BCVA<20/32 group (all P<0.05). A significant reduction was observed in FAZ parameters and all VDs 2wk postoperatively. Except for deep perifoveal VD, all VDs recovered only to their preoperative values. The postoperative FAZ parameters were lower during follow-up. Decreases in preoperative deep VDs were correlated with worse postoperative BCVA (Pearson's r=-0.667 and -0.619, respectively). A larger FAZ perimeter (Spearman's r=-0.524) and a lower deep perifoveal VD preoperatively (Pearson's r=0.486) were associated with lower healing stage. CONCLUSION: The status of the deep vasculature may be an indicator of visual acuity in patients with a closed MH. Except for the deep perifoveal region, VD recovers only to preoperative levels.

Retinal Arteriolar Morphometry Based on Full Width at Half Maximum Analysis of Spectral-Domain Optical Coherence Tomography Images.

OBJECTIVES: In this study, we develop a microdensitometry method using full width at half maximum (FWHM) analysis of the retinal vascular structure in a spectral-domain optical coherence tomography (SD-OCT) image and present the application of this method in the morphometry of arteriolar changes during hypertension. METHODS: Two raters using manual and FWHM methods measured retinal vessel outer and lumen diameters in SD-OCT images. Inter-rater reproducibility was measured using coefficients of variation (CV), intraclass correlation coefficient and a Bland-Altman plot. OCT images from forty-three eyes of 43 hypertensive patients and 40 eyes of 40 controls were analyzed using an FWHM approach; wall thickness, wall cross-sectional area (WCSA) and wall to lumen ratio (WLR) were subsequently calculated. RESULTS: Mean difference in inter-rater agreement ranged from -2.713 to 2.658 µm when using a manual method, and ranged from -0.008 to 0.131 µm when using a FWHM approach. The inter-rater CVs were significantly less for the FWHM approach versus the manual method (P < 0.05). Compared with controls, the wall thickness, WCSA and WLR of retinal arterioles were increased in the hypertensive patients, particular in diabetic hypertensive patients. CONCLUSIONS: The microdensitometry method using a FWHM algorithm markedly improved inter-rater reproducibility of arteriolar morphometric analysis, and SD-OCT may represent a promising noninvasive method for in vivo arteriolar morphometry.

[Efficacy of modified Roux-en-Y gastric bypass in the treatment of non-obese type 2 diabetes mellitus:one year follow-up].

OBJECTIVE: To evaluate the one year effect of modified Roux-en-Y gastric bypass (RYGP) in the treatment of non-obese type 2 diabetes and to investigate the reasonable indications for surgery. METHODS: Totally 72 patients diagnosed as type 2 diabetes underwent RYGP from May 2009 to June 2010. There were 45 male and 27 female patients, with an average age of (47 ± 10) years. Preoperative body mass index (BMI) of the patients was 18.69 to 31.22 kg/m(2), average (26 ± 4) kg/m(2). The follow-up data included fasting plasma glucose (FPG), 2 h plasma glucose after oral glucose challenge (2hPG), weight, BMI and medication usage in 1, 3, 6 and 12 months postoperative; hemoglobin A1c (HbA1c), fasting C-peptide (C-P), fasting serum insulin (Fins) and homeostasis model assessment of insulin resistance index (HOMA-IR) in 6 and 12 months postoperative, respectively. RESULTS: Compared with the preoperative, FPG, 2hPG, weight and BMI in 1, 3, 6 and 12 months after surgery were improved (t = 7.014 to 10.254, P = 0.000), while HbA1c, C-P and HOMA-IR in 6 and 12 months after surgery were improved (t = 1.782 to 7.789, P = 0.000 to 0.103) and there was no significant difference in Fins (P > 0.05). The rates of complete remission in 1, 3, 6 and 12 months after surgery were gradually improved to 22.2%, 27.8%, 36.1% and 60.6%, respectively, and the rate of remission in 1 year was 94.3%. The complete remission of 1 year after surgery was associated with normal C-P, insulin antibody and oral antidiabetic drugs (χ(2) = 11.730, P = 0.003; χ(2) = 7.131, P = 0.028;χ(2) = 6.149, P = 0.046). CONCLUSIONS: Modified RYGP is safely and effectively in the treatment of no-obese type 2 diabetes patients. The function of islet cells is significantly improved after operation. Especially for the patients of whom C-P is normal, insulin antibody is negative before surgery, the rate of complete remission after 1 year is better.

[Selection of sentinel sites for death surveillance, using cluster or unequal probability sampling].

UNLABELLED: To compare the sampling errors from cluster or unequal probability sampling designs and to adopt the unequal probability sampling method to be used for death surveillance. Taking 107 areas from the county level in Shaanxi province as the sampling frame, a set of samples are drawn by equal probability cluster sampling and unequal probability designs methodologies. Sampling error and effect of each design are estimated according to their complex sample plans. Both the sampling errors depend on the sampling plan and the errors of equal probability in stratified cluster sampling appears to be less than simple cluster sampling. The design effects of unequal probability stratified cluster sampling, such as piPS design, are slightly lower than those of equal probability stratified cluster sampling, but the unequal probability stratified cluster sampling can cover a wider scope of monitoring population. CONCLUSIONS: Results from the analysis of sampling data can not be conducted without consideration of the sampling plan when the sampling frame is finite and a given sampling plan and parameters, such as sampling proportion and population weights, are assigned in advance. Unequal probability cluster sampling designs seems to be more appropriate in selecting the national death surveillance sites since more available monitoring data can be obtained and having more weight in estimating the mortality for the whole province or the municipality to be selected.