Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness measurements between healthy and diabetic eyes among Chinese adults.

PURPOSE: To compare intra-retinal layer thickness measurements between eyes with no or mild diabetic retinopathy (DR) and age-matched controls using Spectralis spectral-domain optical coherence tomography (SD-OCT). METHODS: Cross-sectional observational analysis study. High-resolution macular volume scans (30° * 25°) were obtained for 133 type 2 diabetes mellitus (T2DM) patients with no DR, 42 T2DM patients with mild DR and 115 healthy controls. The mean thickness was measured in all 9 Early Treatment Diabetic Retinopathy Study (ETDRS) sectors for 8 separate layers, inner retinal layer (IRL), outer retinal layer (ORL) and total retina (TR), after automated segmentation. The ETDRS grid consisted of three concentric circles of 1-, 3-, and 6-mm diameter. The superior, inferior, temporal, and nasal sectors of the 3- and 6-mm circles were respectively designated as S3, I3, T3, and N3 and S6, I6, T6, and N6. Linear regression analyses were conducted to evaluate the associations between the intra-retinal layer thicknesses, age, diabetes duration, fasting blood glucose and HbA1c. RESULTS: The mean age and duration of T2DM were 61.1 and 13.7 years, respectively. Although no significant differences in the average TR and ORL volumes were observed among the groups, significant differences were found in the volume and sectorial thicknesses of the inner plexiform layer (IPL), outer plexiform layer (OPL) and IRL among the groups. In particular, the thicknesses of the IPL (S3, T3, S6, I6 and T6 sectors) and the IRL (S6 sector) were decreased in the no-DR group compared with the controls (P < 0.05). The thickness of the OPL (S3, N3, S6 and N6 sectors) was thinner in the no-DR group than in mild DR (P < 0.05). The average IPL thickness was significantly negatively correlated with age and the duration of diabetes. CONCLUSION: The assessment of the intra-retinal layer thickness showed a significant decrease in the IPL and IRL thicknesses in Chinese adults with T2DM, even in the absence of visible microvascular signs of DR.

Population-based survey of prevalence, causes, and risk factors for blindness and visual impairment in an aging Chinese metropolitan population.

AIM: To assess the prevalence, causes, and risk factors for blindness and visual impairment among elderly (≥60 years of age) Chinese people in a metropolitan area of Shanghai, China. METHODS: Random cluster sampling was conducted to identify participants among residents ≥60 years of age living in the Xietu Block, Xuhui District, Shanghai, China. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were checked by the Early Treatment Diabetic Retinopathy Study (ETDRS) visual chart. All eligible participants underwent a comprehensive eye examination. Blindness and visual impairment were defined according to World Health Organization (WHO) criteria. RESULTS: A total of 4190 persons (1688 men and 2502 women) participated in the study, and the response rate was 91.1%. Based on PVA, the prevalence of blindness was 1.1% and that of visual impairment was 7.6%. Based on BCVA, the prevalence of blindness and visual impairment decreased to 0.9% and 3.9%, respectively. Older (≥80 years of age) women, with low educational levels and smoking habits, exhibited a significantly greater chance for blindness and visual impairment than did those with high educational levels and no smoking habits (P<0.05). Based on PVA and BCVA, the main causes of blindness were cataract, myopic maculopathy, and age-related macular degeneration (AMD). CONCLUSION: Our findings help to identify the population in need of intervention, to highlight the need for additional eye healthcare services in urban China.

[Integration sites and their characteristic analysis of piggyBac transposon in cattle genome].

As a useful tool for genetic engineering, piggyBac (PB) transposons have been widely used in more than one species of transgenosis or generating mutation studies. At present, the studies about PB transposons in cattle were few. In order to get the PB transposon integration sites and summarize its characteristics in bovine genome, donor plasmid of PB[CMV-EGFP] and helper-dependent plasmid of pcDNA-PBase were constructed and transferred into bovine fibroblasts by Amaxa basic nucleofector kit for primary mammalian fibroblasts. Cell clones stably transfected were obtained after screening by G-418. Genomic DNA of transgenic cells was extracted and the integration sites of PB transposon were detected by genome walking technology. Eight integration sites were obtained in bovine genome, although only 5 sites were mapped on chromosomes 1, 2, 11, and X chromosome. We found that PB transposon was inserted into the "TTAA" location and integrated into the intergenic non-regulatory sites between two genes. Analysis of the composition of the five bases, which was close to the side of the PB integration sites "TTAA", showed that PB 5' tended to be inserted into region rich in GC (62.5%). From the study, we got that transposition occurred in cattle genome by PB transposons and the integration site information acquired from the research will provide theoretical references for bovine study by PB transposon.

Evaluating subconjunctival bleb function after trabeculectomy using slit-lamp optical coherence tomography and ultrasound biomicroscopy.

BACKGROUND: The existing classifications for evaluating glaucoma filtering blebs rely mostly on external bleb characteristics and the postoperative control of intraocular pressure (IOP). Internal bleb structures are not carefully observed. This study aimed to analyze and compare glaucoma filtering bleb morphology using slit-lamp-adapted optical coherence tomography (SL-OCT) and ultrasound biomicroscopy (UBM), and to classify blebs according to results and intraocular pressure. METHODS: We followed 29 eyes of 21 male patients and 40 eyes of 32 female patients who underwent glaucoma filtering surgery in Sixth People's Hospital of Shanghai, between 2002 and 2006. The blebs were imaged using SL-OCT and UBM and classified according to the intrableb morphology and control of IOP after surgery. A Fisher's exact test was used to compare the sensitivity for predicting a functioning bleb differed significantly between SL-OCT and UBM. A Fisher's exact test was also used for morphological analysis of the trabeculectomy blebs based on SL-OCT. RESULTS: In the 69 eyes, there were 45 (65.2%) functioning blebs and 24 (34.8%) non-functioning blebs. We classified the blebs into four categories on the basis of SL-OCT images: diffuse, cystic, encapsulated and flat. Diffuse and cystic blebs were typically functional, whereas the other two types were always non-functional. The sensitivity of SL-OCT for predicting a functioning bleb was 92.7% (38/41 eyes) and specificity of predicting a non-functioning bleb was 83.3% (20/24 eyes). By contrast, sensitivity of UBM was 66.7% (30/45 eyes) and specificity was 75.0% (18/24 eyes). The sensitivity for predicting a functioning bleb differed significantly between the two techniques (P = 0.003). CONCLUSIONS: SL-OCT provides high-axial-resolution images of anterior segment structures. The non-contact approach of SL-OCT enables visualization of intrableb structures at any time after surgery. SL-OCT has greater sensitivity and specificity than UBM in evaluating filtering bleb function. The morphological classification supported the assessment of bleb function and could provide objective data for evaluating the outcome of antiglaucoma surgery or the need for a second procedure.

[Evaluation of photodynamic therapy in idiopathic choroidal neovascularization].

OBJECTIVE: To evaluate the effectiveness of photodynamic therapy (PDT) in the treatment of idiopathic choroidal neovascularization (CNV). METHODS: Sixty-one cases (61 eyes) of CNV were treated with PDT and the fundus appearance, visual acuity, retina thickness as well as the fundus angiographic imaging were observed before and after the therapy. PDT was performed 1.2 times in average and the follow-up period was 6 - 36 months (mean 19 months). RESULTS: At the last follow up, the visual acuity was improved in 41 eyes (67.2%), unchanged in 15 eyes (24.6%) and slightly decreased in 5 eyes (8.2%). Macular hemorrhage and exudation reduced in all cases after PDT. Fundus angiography showed complete closure of CNV in 38 eyes (62.3%), partial closure in 4 eyes (6.6%), incomplete closure in 14 eyes (23.0%) and recurrence in 5 eyes (8.2%). In 6 eyes CNV was complete closed after single PDT with diminish of macular edema and neuronal retinal epithelial detachment. No recurrent CNV was observed during three years' follow-up and the visual acuity remained stable. Our results also demonstrated that the therapeutic effect decreased with patient's age (t = 0.476, P = 0.016). The decrease of visual acuity averaged 0.008 per year. CONCLUSION: Photodynamic therapy is a potential treatment for idiopathic CNV and better outcomes are achieved in younger patients.

[Clinical research of the implantation of phakic anterior chamber intraocular lens for high myopia].

OBJECTIVE: To investigate the efficacy and safety of the implantation of phakic anterior chamber intraocular lens (IOL) for high myopia. METHODS: A consecutive group of 73 eyes in 41 patients with -7.00 to -30.00 diopters (D) of myopia were implanted. RESULTS: All of 73 eyes were implanted successfully and have been followed-up for 3 m (months). The uncorrected visual acuity was from FC/33 cm to 0.2 pre-operatively and 0.1 to 1.0 3 m post-operatively. The best corrected visual acuity (BCVA) was from 0.05 to 1.0 pre-operatively and 0.1 to 1.0 3 m post-operatively. The post-operative BCVA of every eye was not worse than the pre-operative one. The refractive diopters were from -7.00 to -30.00 D pre-operatively and -6.00 to +2.50 D 3 m post-operatively. There were no significant differences between pre- and 3 m post-operative mean corneal astigmatism (t = 1.751, P = 0.082) and mean intraocular pressure (IOP) (t = 1.181, P = 0.240), respectively. The mean counts of endothelial cells was (2 680 +/- 538)/mm(2) pre-operatively and (2 514 +/- 420)/mm(2) 3 m post-operatively. There was no significant difference (t = 1.182, P = 0.242) though it decreased 6.19%. No severe complications occurred. CONCLUSIONS: The implantation of phakic anterior chamber IOL for high myopia is predictable, reversible and controllable with simple manipulation. No severe complication occurred in 3 m post-operatively, and long-time follow-up is still required.

[Application of capsular tension ring in cataract surgery for zonular dialysis].

OBJECTIVE: To evaluate the application of capsular tension ring (CTR) in the cataract surgery for zonular dialysis. METHODS: Eleven cases of partially traumatized zonular dialysis patients were managed with CTR after continuous curvilinear capsulorrhexis (CCC), cataract extraction and posterior chamber intraocular lens (IOL) implantation. RESULTS: The IOLs in all the eyes were basically in the normal position without tilting or obvious decentration. One month postoperatively, the best-corrected visual acuity (BCVA) was 0.4 in 4 eyes, 0.5-0.8 in 5 eyes and over 0.8 in 2 eyes. A side-by-side overlap of both eyelets of the ring happened in 1 eye due to the bigger diameter of CTR, and no other complications were seen except the original complication of cataract surgery. CONCLUSIONS: For the patients of zonular dialysis, the CTR can preserve the integrity of the capsular bag, provide the necessary capsular space while giving a counter-traction, reduce asymmetric capsular forces, stabilize the vitreous base, facilitate phacoemulsification, aspiration of cortex and IOL implantation, prevent the postoperative IOL decentration and allow a quicker visual recovery. The CTR is a useful device that effectively supplements the currently available cataract surgery armamentarium, and develops the application of posterior chamber IOL implantation.