In vivo quantification of human aqueous veins by enhanced depth imaging optical coherence tomography and optical coherence tomography angiography images.

AIM: To investigate the aqueous vein in vivo by using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA). METHODS: In this cross-sectional comparative study, 30 healthy participants were enrolled. Images of the aqueous and conjunctival veins were captured by EDI-OCT and OCTA before and after water loading. The area, height, width, location depth and blood flow of the aqueous vein and conjunctival vein were measured by Image J software. RESULTS: In the static state, the area of the aqueous vein was 8166.7±3272.7 µm2, which was smaller than that of the conjunctival vein (13 690±7457 µm2, P<0.001). The mean blood flow density of the aqueous vein was 35.3%±12.6%, which was significantly less than that of the conjunctival vein (51.5%±10.6%, P<0.001). After water loading, the area of the aqueous vein decreased significantly from 8725.8±779.4 µm2 (baseline) to 7005.2±566.2 µm2 at 45min but rose to 7863.0±703.2 µm2 at 60min (P=0.032). The blood flow density of the aqueous vein decreased significantly from 41.2%±4.5% (baseline) to 35.4%±3.2% at 30min but returned to 45.6%±3.6% at 60min (P=0.021). CONCLUSION: The structure and blood flow density of the aqueous vein can be effectively evaluated by OCT and OCTA. These may become biological indicators to evaluate aqueous vein changes and aqueous outflow resistance under different interventions in glaucoma patients.

Numerical simulation of the flow of aqueous humor in the Schlemm's canal.

Schlemm's canal (SC) is a ring structure responsible for maintaining fluid homeostasis in the anterior chamber of the eye by draining aqueous humor (AH) from the trabecular meshwork (TM) into the collecting channel (CC). Obstruction of the AH flow in this conventional pathway leads to an elevation of intraocular pressure in glaucoma, which is internationally recognized as the most common cause of blindness. Although there are obvious morphological differences between patients and healthy individuals, the AH drainage capacity of SC with specific parameters is difficult to quantitatively evaluate due to the limitations of analyses or experimental technologies. In this paper, the AH flow dynamic features under various SC morphological parameters are studied by numerical simulations of 3D models. The axis length of the SC cross-section and the level of openness are chosen as the main morphological factors according to the clinical data. The flow features, including the velocity, streamline and wall shear stress, are analyzed. This study aimed not only to explore the feasibility of 3D numerical modeling in evaluating the SC drainage capacity, but also to reveal the relationship between SC morphological parameters and the dynamic features of AH drainage.

Association between prenatal exposure to ambient particulate matter and risk of hypospadias in offspring: A systematic review and meta-analysis.

BACKGROUND: Epidemiological studies on whether prenatal exposure to PM2.5, PM2.5-10, and PM10 increases the risk of hypospadias are limited and the results are inconsistent. OBJECTIVES: We conducted this systematic review and meta-analysis to evaluate these associations. METHODS: Relevant studies were identified by searching the PubMed and Embase databases up to the end of February 2020. Observational studies that investigated the relationships between prenatal exposure to PM10, PM2.5, and PM2.5-10 and the risk of hypospadias in offspring were eligible for the review. The risk of bias was evaluated using the Newcastle-Ottawa scale. Random-effects models were used to estimate pooled relative risks (RRs) and 95% confidence intervals (CIs) for the associations. RESULTS: Nine studies (two cohort and seven case-control studies) with a total of 2806 hypospadias cases were included. Eight studies were at low risk of bias and only one study was at high risk of bias. Five studies reported the association between per interquartile range increase in PM2.5 exposure within the first trimester and the risk of hypospadias. The pooled RR was 1.17 (95% CI: 1.00, 1.36). Two studies reported the per interquartile range increase in PM2.5 exposure during 1 month before pregnancy associated with the risk of hypospadias, with a pooled RR of 1.25 (95% CI: 1.03, 1.51). No association was observed between PM2.5-10 and PM10 exposure during pregnancy and the risk of hypospadias in offspring. CONCLUSION: This study suggested a modest association between prenatal PM2.5 exposure during 1 month before pregnancy or within the first trimester and the risk of hypospadias in offspring. Further large-scale cohort studies are required to verify this association.

[Prevalence of simple obesity and its high-risk factors in preschool children in Fuzhou, China].

OBJECTIVE: To investigate the prevalence of simple obesity and its risk factors in preschool children in Fuzhou, China. METHODS: The physical examination data of 14 kindergartens in Fuzhou, China were collected by stratified cluster random sampling. The detection rate of simple obesity was calculated. The children with normal body weight were selected as the control group by 1:1 case-control method. The risk factors for childhood simple obesity were investigated by self-made questionnaire and multivariate logistic regression analysis. RESULTS: A total of 5 767 children aged 3-6 years were enrolled in this study. A total of 289 (5.01%) children with simple obesity were screened out, including 153 with mild obesity and 136 with moderate to severe obesity. The prevalence rate of simple obesity gradually increased with the age of children. The multivariate logistic regression analysis showed that the following factors were independent risk factors for simple obesity: preference for fried food (OR=4.789, P<0.05), caregivers' over-concern about diet (OR=4.620, P<0.05), eating before sleep (OR=4.006, P<0.05), eating fast (OR=3.221, P<0.05), preference for sweets (OR=2.282, P<0.05), high birth weight (OR=2.202, P<0.05), overweight or obesity in father (OR=2.074, P<0.05), overweight or obesity in mother (OR=2.047, P<0.05), more than 1.2 times the food intake at the same age (OR=2.013, P<0.05), watching TV (OR=1.665, P<0.05), and lack of exercise (OR=1.463, P<0.05). CONCLUSIONS: The prevalence rate of simple obesity is 5.01% in preschool children in Fuzhou, China. The development of simple obesity is multifactorial. It is suggested that doctors, parents, and teachers should strengthen health education for preschool children, help them develop good living and eating habits, and encourage them to take more exercise, in order to reduce the development of simple obesity.

[Efficacy of clonidine transdermal patch in treatment of moderate to severe tic disorders in children].

OBJECTIVE: To investigate the difference in the efficacy between clonidine transdermal patch and haloperidol tablets in the treatment of moderate to severe tic disorders in children. METHODS: A total of 134 children with moderate to severe tic disorders were randomly divided into clonidine group (n=70) and haloperidol group (n=64). The clonidine and haloperidol groups were treated with clonidine transdermal patch and haloperidol tablets respectively, and the treatment lasted for 8 weeks in both groups. The Yale Global Tic Severity Scale (YGTSS) was used to evaluate the conditions of the children before and after treatment, and the adverse events during the treatment were recorded. RESULTS: The haloperidol group had a significantly better treatment outcome than the clonidine group after one week of treatment (P<0.05); the treatment outcome showed no significant difference between the two groups after 3, 5, and 8 weeks of treatment (P>0.05). The clonidine group had significantly less reductions in the motor tics, vocal tics, and function impairment scores and total score of YGTSS than the haloperidol group after one week of treatment (P<0.05); there were no significant differences in YGTSS score reductions between the two groups after 3, 5, and 8 weeks of treatment (P>0.05). The clonidine group had a significantly lower overall incidence of adverse events than the haloperidol group (8% vs 37%; P<0.01). CONCLUSIONS: Clonidine transdermal patch and haloperidol are both effective in the treatment of moderate to severe tic disorders in children. The clonidine transdermal patch, despite slow action, has comparable efficacy and fewer adverse effects compared with haloperidol.

Choroidal area assessment in various fundus sectors of patients at different stages of primary open-angle glaucoma by using enhanced depth imaging optical coherence tomography.

To compare the choroidal area in different eye fundus sectors of subjects with normal eyes, early-stage primary open-angle glaucoma (POAG) eyes, and 10° tubular visual field POAG eyes using enhanced depth imaging optical coherence tomography.Twenty-five normal, 25 early-stage POAG, and 25 ten-degree tubular visual field POAG eyes were recruited. Enhanced depth imaging optical coherence tomography was used to measure the choroidal area in different fundus sectors (fovea; 10° superior, inferior, temporal, and 24° superior, inferior, temporal, nasal to the fovea) and the peripapillary sector.There were neither significant differences in the choroidal area at any of the 8 measured fundus sectors, nor significant differences in the percentage change between the choroidal area of the fovea and other 7 measured fundus sectors among the 3 groups (all P > 0.05). For the total peripapillary choroidal area, no significant difference was found among the 3 groups (P > 0.05); however, the temporal peripapillary choroidal area of 10° tubular visual field POAG eyes was significantly thicker than that of normal eyes (4,46,213 ±â€Š1,16,267 vs 3,74,164 ±â€Š1,21,658 µm; P = 0.048).Our study showed that there was no significant difference in the choroidal area of the 8 measured fundus sectors among normal, early-stage POAG, and 10° tubular visual field POAG eyes, suggesting that there might be no blood redistribution from the peripheral choroid to the subfoveal choroid. However, the thicker temporal peripapillary choroidal area might play a role in the central visual acuity protection in patients with POAG.

Anterior segment changes after pharmacologic mydriasis using Pentacam and optical coherence tomography in angle closure suspects.

AIM: To compare the dynamic changes of anterior segment parameters especially iris morphology induced by pharmacologic mydriasis between angle closure suspects and normal controls. METHODS: The study group comprised 19 eyes of 19 angle closure suspects and 19 eyes of 19 age- and sex-matched normal open-angle eyes. Pentacam and optical coherence tomography measurements before and 30min after instillation of compound tropicamide eye drop were performed and compared. Biometric evaluations of iris tomography and anterior chamber angle were estimated by a customized image-processing software. RESULTS: Baseline axial length, iris cross sectional area and volume did not differ significantly between angle closure suspects and normal controls. Angle closure suspects had smaller pupil size, narrower anterior segment dimension and axial length, thinner iris with greater curve in comparison with normal controls. Pharmacologic mydriasis led to significant increments in iris thickness at 750 µm, anterior chamber depth and volume, whereas significant decrements in iris curve, cross sectional area and volume in both groups. Angle opening distance at 500 µm was increased significantly in normal controls (from 0.465±0.115 mm to 0.539±0.167 mm, P=0.009), but not in angle closure suspects (from 0.125±0.100 mm to 0.145±0.131 mm, P=0.326). Iris volume change per millimeter of pupil dilation (ΔIV/ΔPD) decreased significantly less in angle closure suspects than normal controls (-2.47±1.33 mm(2) vs -3.63±1.58 mm(2), P=0.019). Linear regression analysis showed that the change of angle opening distance at 500 µm was associated most with the change of central anterior chamber depth (ß=0.841, P=0.002) and ΔIV/ΔPD (ß=0.028, P=0.002), followed by gender (ß=0.062, P=0.032). CONCLUSION: Smaller iris volume decrement per millimeter of pupil dilation is related significantly with the less anterior angle opening in angle closure suspects after pharmacologic mydriasis. Dynamic iris change may be as a prospective indicator of iris compressibility and angle closure glaucoma.

Autologous sclera-muscle flaps technique in evisceration with hydroxyapatite implantation.

AIM: To provide superior cosmetic results and reduce complications, unlike traditional evisceration coupled with implant insertion technique and its modifications, we have developed a novel and simple technique for anophthalmic patients. METHODS: All patients who underwent the scleral-muscle flaps procedure in evisceration with the placement of hydroxyapatite implant were included in the study. Main outcome measures were complications such as exposure, infection, chemosis, conjunctival inclusion cysts, granulomas. Meanwhile, implant motility was indirectly measured and the results were collected and analyzed. RESULTS: A total of twenty-eight patients were enrolled in the study. Eighteen were men (64.29%) and ten were women (35.71%). Ages ranged from 18 to 65y (mean age, 32 years old). Mean follow-up was 12.32mo (range, 9-16mo). All patients received a hydroxyapatite implant. The average diameter of the implant was 19.29±1.36 mm (range, 18-22 mm). Minor complications occurred in 3 patients, and a major complication was observed in 1 patient. Mean motility were 11.04±1.45 mm horizontally (range, 7-14 mm) and 8.57±1.50 mm vertically (range, 5-12 mm). CONCLUSION: The sclera-muscle flaps technique in evisceration with hydroxyapatite implantation is simple and practical that eases the surgical procedure, enables a proper size hydroxyapatite implantation, distinctively reduces complications and provides superior surgery results, especially the motility of the implant.