Zhongshan, China
Zhongshan, China

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How A.C.,Singapore Eye Research Institute | Baskaran M.,Singapore Eye Research Institute | Kumar R.S.,Singapore Eye Research Institute | He M.,Zhongshan Ophthalmic Center | And 8 more authors.
Ophthalmology | Year: 2012

Purpose: Novel anterior segment optical coherence tomography (ASOCT) parameters associated with angle closure include anterior chamber area (ACA), anterior chamber volume (ACV), anterior chamber width (ACW), lens vault (LV), iris thickness (IT), iris area (I-area), and iris curvature (I-curv). We aimed to investigate changes in these parameters after laser peripheral iridotomy (LPI) in a cohort of primary angle-closure suspects (PACS). Design: Prospective observational study. Participants and Controls: A total of 176 PACS aged <50 years who underwent LPI in 1 eye. Methods: We analyzed ASOCT images (Visante, Carl Zeiss Meditec, Dublin, CA) from all subjects using customized software before and 1 week after LPI. Multivariate linear regression analysis was performed for predictors of percentage change in mean angle opening distance (AOD750). Main Outcome Measures: Change in ASOCT parameters after LPI. Results: The mean age of participants was 63±7.3 years. The majority of subjects were Chinese (95.5%) and women (76.7%). Mean angle width (modified Shaffer grade) changed from 0.68±0.54 at baseline to 1.76±0.69 after LPI (P<0.001) with a corresponding increase in mean AOD500 (0.12 vs. 0.19 mm, P<0.001), trabecular iris surface area (TISA500, 0.06 vs. 0.08 mm 2, P<0.001), and angle recess area (ARA, 0.13 vs. 0.17 mm 2, P<0.001). Mean ACA (15.0 vs. 16.0 mm 2, P<0.001) and ACV (91.6 vs. 103.0 mm 3, P<0.001) increased significantly after LPI, but there was no change in ACW, anterior chamber depth (ACD), or LV. Mean I-curv was reduced (0.375 vs. 0.18 mm, P<0.001) after LPI, but there was no significant change in IT or I-area. After multivariate analysis, mean LV (β = 0.286, P = 0.001), mean IT at 2000 μm (IT2000, β = 0.172, P = 0.034), and intraocular pressure (β = 0.159, P = 0.042) at baseline were found to be associated with ΔAOD750. Conclusions: This study confirms that LPI results in a significant increase in the angle width in PACS. The ACA and ACV increased after LPI, but there was no change in ACD, ACW, LV, IT, or I-area. The increase in ACA/ACV was mainly due to decreased I-curv after LPI. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology.

Yuen L.H.,11 Third Hospital Avenue | He M.,Zhongshan Ophthalmic Center | Aung T.,11 Third Hospital Avenue | Htoon H.M.,Singapore Eye Research Institute | And 3 more authors.
Investigative Ophthalmology and Visual Science | Year: 2010

Purpose. To investigate the normative data of corneal and anterior segment biometric parameters and their associations in Chinese adults, for use in preoperative assessment for corneal and anterior segment surgery. Methods. This cross-sectional, population-based study included 750 subjects aged ≥50 years. The subjects underwent an ophthalmic examination including imaging with anterior segment optical coherence tomography (AS-OCT). Dimensions were subsequently measured with the Zhongshan Assessment Program (ZAP). Also measured was posterior corneal arc length (PCAL), a novel parameter defined as the arc distance between scleral spurs on the posterior border of the cornea. Correlations with age, sex, height, weight, body mass index (BMI), refractive sphere and cylinder, and intraocular pressure were also measured. Results. The subjects' mean age was 63.3 ± 7.9 years and 349 (46.5%) were men. Corneal parameters (mean ± SD) included PCAL (12.924 ± 0.544 mm), anterior chamber depth (ACD; 2.684 ± 0.309 mm), central corneal thickness (562.39 ± 31.85 fjim), anterior chamber curvature (7.35 ± 0.37 mm), and posterior corneal curvature (6.65 ± 0.34 mm). A moderate correlation was observed between PCAL and ACD (R = 0.55, P < 0.001) and a poor correlation between PCAL and age, height, weight, and BMI. Multivariate analysis showed a significant association between PCAL and ACD, ACC, PCC, and cylinder (P < 0.05).Conclusions. In this Chinese population, PCAL was found to correlate moderately with ACD. The data may be useful for corneal and anterior segment procedures such as Descemet's stripping automated endothelial keratoplasty (DSAEK). © Association for Research in Vision and Ophthalmology.

Narayanaswamy A.,Singapore Eye Research Institute | Sakata L.M.,Federal University of Paraná | He M.-G.,Zhongshan Ophthalmic Center | Friedman D.S.,Wilmer Eye Institute | And 6 more authors.
Archives of Ophthalmology | Year: 2010

Objective: To assess the diagnostic performance of angle measurements from anterior segment optical coherence tomography (AS-OCT) images for identifying eyes with narrow angles. Methods: We conducted a community-based cross-sectional study of individuals 50 years or older who had phakic eyes and who underwent AS-OCT imaging in the dark by a single operator and gonioscopy by an ophthalmologist masked to AS-OCT findings. An eye was considered to have narrow angles if the posterior pigmented trabecular meshwork was not visible for at least 180° on gonioscopy. Horizontal AS-OCT images were analyzed for the following measurements using customized software: angle opening distance (AOD) at 250, 500, and 750 μm from the scleral spur; trabecular-iris space area (TISA) at 500 and 750 μm; and angle recess area (ARA) at 750 μm. Areas under the receiver operating characteristic curves (AUCs) were generated for AOD, TISA, and ARA to assess the performance of these measurements in detecting eyes with narrow angles. Results: Of 2047 individuals examined, 582 were excluded mostly because of poor image quality or inability to locate the scleral spur. Of the remaining 1465 participants, 315 (21.5%) had narrow angles on gonioscopy. Mean (SD) age was 62.7 (7.7) years, 54.1% were women, and 90.0% were Chinese. The AUCs were highest for AOD750 in the nasal (0.90 [95% confidence interval, 0.89-0.92]) and temporal (0.91 [0.90-0.93]) quadrants. Conclusions: The AOD750 is the most useful angle measurement for identifying individuals with gonioscopic narrow angles in gradable AS-OCT images. Poor definition of the scleral spur precludes quantitative analysis in approximately 25% of AS-OCT images. ©2010 American Medical Association. All rights reserved.

News Article | March 16, 2016
Site: www.nature.com

All animal studies were performed with the approval of the Institutional Animal Care Committees of Sun Yat-sen University, the University of California San Diego, West China Hospital, and the University of Texas Southwestern Medical Center. The eyeball was enucleated from a one-month-old New Zealand white rabbit and washed with PBS (containing antibiotics) three times. After the cornea and iris were removed, a small cut was made in the posterior capsule of the lens; the capsule with attached epithelium was removed and cut into 1 × 1 mm2 pieces. The pieces of epithelium were cultured in minimum essential media supplemented with 20% FBS, NEAA, and 50 μg ml−1 gentamicin. A 17-week-old human fetal eyeball was purchased from Advanced Bioscience Resources, Inc. (San Francisco, California). Post-mortem human eyes were obtained from San Diego Eye Bank. The human LECs were cultured according to the same methods as above. For in vitro differentiation, LECs were cultured on Matrigel-coated six-well plates or eight-well chambers. Lentoid body was formed after 21 days in minimum essential media supplemented with NEAA, 1% FBS, 100 ng ml−1 FGF2, and 5 μg ml−1 insulin. Images of lentoid tissue were obtained using a Leica M205FA stereo microscope. Membrane-tomato/membrane-green (mTmG)-targeted ROSAmTmG mice were purchased from the Jackson Laboratory (Bar Harbour, ME; stock no. 7576) and maintained as homozygotes. P0-3.9-GFPcre mice expressing an eGFP–Cre recombinase fusion protein under the control of the Pax6 lens ectoderm enhancer and the Pax6 P0 promoter26 were maintained in a FVB/N background. Lineage-tracing experiments were performed by crossing the homozygous ROSAmTmG reporter mouse strain with the P0-3.9-GFPcre deleter strain. Eyes were dissected at P1, P14, and P30 and fixed overnight in 4% formaldehyde. Tissues were then incubated in 10% sucrose and embedded in OCT for cryo-sectioning. Frozen sections were washed in PBS and imaged on a Zeiss Axio Imager fluorescence microscope. Bmi1fl/fl mice were generated as previously described27. Nestin-cre mice28 were obtained from the Jackson Laboratory. For BrdU pulses, mice were injected with 100 mg kg−1 BrdU (Sigma) dissolved in PBS, then maintained on drinking water that contained 1 mg ml−1 BrdU until sacrifice. For gene expression studies, lenses of Pax6P0-3.9-GFPcre mice were dissected under a dissecting microscope. Lens capsular bag was opened from the posterior surface by making three crisscross incisions. The capsular bag was opens and lens material extruded. GFP-positive LECs in the mid-anterior capsular area were separated mechanically from GFP-negative LECs in the remaining capsular areas under a fluorescence microscope. RNA was isolated using RNeasy Mini Kit (Qiagen). To image cataracts, mice were anaesthetized with Avertin, and one drop of 1% Mydriacyl (Alcon) was administered per eye. Eyes were immediately visualized in vivo using a light microscope. For histology, mice were perfused with heparinized saline followed by 4% paraformaldehyde (PFA) in PBS. Dissected eyes were fixed in 4% PFA overnight, embedded in paraffin, and sectioned by the UT Southwestern Molecular Pathology core facility. For BrdU staining, slides were deparaffinized, and subjected to heat-mediated antigen retrieval (in 10 mM sodium citrate, pH 6.0). Slides were stained with primary mouse anti-BrdU (Caltag, MD5000, 1:200) overnight at 4 °C. Slides were subsequently stained with Alexa Fluor 555-conjugated goat anti-mouse IgG1 secondary antibody (Life Technologies, 1:500) and 1 mg ml−1 DAPI (1:500) for 1 h at room temperature. The number of BrdU-labelled cells was divided by the total number of DAPI+ cells in a single layer of LECs. Lentiviral shRNA targeting the human BMI1 gene (NCBI Reference Sequence: NM_005180.8) was purchased from Origene (TL314462), ShRNA targeting sequences were as follow: 5′-AATGCCATATTGGTATATGACATAACAGG-3′ and 5′-GTAAGAATCAGATGGCATTATGCTTGTTG-3′. Two shRNAs were used separately, and a non-effective 29-mer scrambled shRNA was used as a control. Lentiviral shRNA particles were prepared using shRNA lentiviral packaging kit (Origene, TR30022). Viruses were harvested at 48 h and 72 h post-transfection. LECs were cultured on Matrigel-coated 3.5-mm dishes with lentoid formation medium for 30 days. Cells were washed twice with ice-cold PBS, and lysed in RIPA lysis buffer with PMSF. Protein concentration was determined by BCA protein assay kit. Thirty micrograms of total protein lysate was loaded onto 10% SDS–PAGE gel and then transferred to a PVDF membrane (Millipore) at 70 V for 2 h. The membrane was probed with the following primary antibody at 4 °C overnight: anti-αA-crystallin (sc-22389, Santa Cruz), anti-β-crystallin (sc-48335, Santa Cruz), anti-γ-crystallin (sc-22415, Santa Cruz) and anti-β-actin (sc-47778, Santa Cruz), and then incubated with HRP-conjugated anti-rabbit, anti-mouse, or anti-goat secondary antibody for 1 h at room temperature. The immunodetection was visualized using a blot imaging system (Fluor Chem Q, Protein Simple) with ECL buffer (Millipore). New Zealand white rabbits (n = 29, four rabbits died from systemic infections unrelated to surgery. The remaining 25 rabbits were used to assess regeneration), and long-tailed macaques (Macaca fascicularis) monkeys (n = 6) underwent minimally invasive capsulorhexis surgery. Only the left eye of each animal was used for experiments. Slit-lamp biomicroscopy and photography were performed at different time points to monitor lens regeneration. Rabbits were euthanized at day 1, day 7, and one month after surgery, and the treated eyes were enucleated. The lenses were harvested for histologic analysis using haematoxylin and eosin staining. For the macaques, enucleation of the treated eye was performed 4 months post-surgery and the lenses were harvested for the same histologic examinations. The eyes were fixed, paraffin-embedded, and sectioned at 5 μm through the cornea, pupil, and optic nerve with the lens in situ. RNA was isolated from rabbit LECs, mature lens fibre cells and LECs in P0-3.9-GFPcre mice using an RNeasy Mini Kit (Qiagen) and subjected to on-column DNase digestion. cDNA was synthesized using a Superscript III reverse transcriptase kit according to the manufacturer’s instructions (Invitrogen). Quantitative PCR was performed via 40 cycle amplification using gene-specific primers (Supplementary Table 1) and Power SYBR Green PCR Master Mix on a 7500 Real-Time PCR System (Applied Biosystems). Measurements were performed in triplicate and normalized to endogenous GAPDH levels. The relative fold change in expression was calculated using the ΔΔC method (C values <30). Rabbit LECs were fixed in 4% PFA for 20 min, then permeabilized with 0.3% Triton X-100-PBS for 10 min and blocked in PBS solution containing 5% BSA, followed by an overnight incubation in primary antibodies at 4 °C. After three washes in PBS, cells were incubated with secondary antibody for 1 h in room temperature. Cell nuclei were counterstained with DAPI. The following antibodies were used: goat anti-Sox2 polyclonal antibody (Santa Cruz), rabbit anti-PAX6 polyclonal antibody (PRB-278P, Covance), mouse anti-Bmi1 antibody (ab14389, Abcam), and mouse anti-Ki67 monoclonal antibody (550609, BD Sciences). The secondary antibodies, Alexa Fluor 488- or 568-conjugated anti-mouse or anti-rabbit IgG (Invitrogen), were used at a dilution of 1:500. Images were obtained using an Olympus FV1000 confocal microscope. We used BrdU labelling to identify and quantify proliferating LECs from human cadaver eyes. Whole-mount human lens capsules were pulsed with BrdU and then stained with an antibody against BrdU to determine the distribution and density of proliferating LECs. In brief, within 12–24 h after death, lenses from post-mortem donor eyes were obtained from the Eye Bank of Zhongshan Ophthalmic Center in Guangzhou, China. Twelve lenses in total from six donors were used for the experiment. A small puncture injury was made on the anterior surface of a post-mortem human lens using a 30-gauge needle. The lenses were cultured at 37 °C in Dulbecco modified Eagle medium (DMEM) supplemented with 10% FBS in a humidified incubator with 5% CO . The contralateral lens from the same donor was treated under the same conditions but did not receive a puncture injury and was used as a control. To label the proliferating LECs, both groups of lenses were incubated in 100 μg ml−1 BrdU (Sigma-Aldrich) 24 h after the puncture injury. The lens was then removed from the capsular bag, and the lens capsules were fixed in 4% formaldehyde and subjected to BrdU staining using a standard immunohistochemistry protocol according to the manufacturer’s instructions (CST, Boston, Massachusetts). Images were taken using a Carl Zeiss microscope (Jena, Germany). This study was approved by the institutional review board of the Zhongshan Ophthalmic Center (ZOC). Informed written consent was obtained from the parents or guardians of the infants before enrolment, and the tenets of the Declaration of Helsinki were followed throughout the study. The study was conducted in accordance with an international guideline and protocol for visual function measurements in paediatric cataract surgery and a protocol of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH) and had an independent data and safety monitoring board of ZOC-CCPMOH. The current standard-of-care treatment for paediatric cataract involves removal of the cataractous lens through a relatively large opening using anterior continuous curvilinear capsulorhexis (ACCC, about 6 mm in diameter, Extended Data Fig. 1), followed by cataract extraction and artificial lens implantation or placement of postoperative aphakic eyeglasses/contact lens in paediatric cataract patients younger than two years. Some patients underwent additional posterior continuous curvilinear capsulorhexis (PCCC) and anterior vitrectomy. We established a new capsulorhexis surgery method to facilitate lens regeneration (Fig. 3a). First, we decreased the size of the capsulorhexis opening to 1.0–1.5 mm in diameter. This results in a minimal wound of about 1.2 mm2 in area, which is only about 4.3% the size of the wound created by the current method. Second, we moved the location of the capsulorhexis to the peripheral area of the lens instead of the central area. A 0.9 mm phacoemulsification probe was used to remove the lens contents and/or cortical opacities. These changes provide significant advantages. First, it considerably reduces the size of the injury, which resulted in a lower incidence of inflammation and much faster healing. Second, it moves the wound scar away from the central visual axis to the periphery, leading to improved visual axis transparency. Third, it preserves a nearly intact transparent lens capsule and layer of LECs, which have regenerative potential and are critically required for the regeneration of a natural lens. The clinical trial is an open label, randomized controlled trial in a study population of paediatric cataract patients (age: 0–2 years). Except the trial participants, all other parties (care providers, outcome assessors) were blinded to treatment allocation. A clinical trial consort flowchart is listed in the Extended Data Fig. 8a. Paediatric patients were enrolled accordingly inclusion and exclusion criteria below (ClinicalTrials.gov identifier: NCT01844258). Inclusion criteria were the following: infants were ≤24 months old, and diagnosed with bilateral uncomplicated congenital cataract with an intact non-fibrotic capsular bag. Exclusion criteria included preoperative intraocular pressure (IOP) >21 mm Hg, premature birth, family history of ocular disease, ocular trauma, or other abnormalities, such as microcornea, persistent hyperplastic primary vitreous, rubella, or Lowe syndrome. In total, twelve paediatric cataract patients (24 eyes) received the new minimally invasive lens surgery (Table 1). Twenty-five paediatric cataract patients (50 eyes in total) were enrolled as the control group to receive the current standard surgical treatment (Extended Data Fig. 8a). Bilateral eye surgeries of the same patient were conducted during the same operation session. We defined the incidence of corneal oedema as a >5% increase in central corneal thickness one week post-surgery, and the incidence of severe anterior chamber inflammation as a Flare value >10 evaluated by Pentacam system (OCULUS, Germany) and Laser flare meter (KOWA FM-600, Japan). Early-onset ocular hypertension was identified as IOP >21 mm Hg by Tonopen (Reichert, Seefeld, Germany) within one month after surgery. Macular oedema was identified by fundus OCT (iVue, Optovue, Germany) as an increase in central macular thickness >10% one week post-surgery. When indicated, VAO, defined by visual decline and the degree to which the fundus was obscured, was treated with YAG laser capsulotomy at follow-up. Compared to infants operated on using our new surgical technique, infants who received the traditional technique had a higher incidence of anterior chamber inflammation one week after surgery, early-onset ocular hypertension, and increased VAO (Table 1). However, in the group treated with our new method, a transparent regenerated biconvex lens was found in 100% of eyes three months after surgery, while no regenerated biconvex lenses formed in the group treated with the standard technique. In addition, 100% of the capsular openings healed within one month after surgery in the experimental group, but no capsular openings healed in the control group. Testing equipment included a set of Teller Acuity Cards (Vistech Consultants, Dayton, Ohio). The set of cards consists of 15 cards with gratings ranging in spatial frequency from 0.32 to 38 cycles per cm, in half-octave steps, and one blank grey card. A 4-mm peephole in each card allows the tester to view the child’s face through the card during testing. Test distance was kept constant by use of an aid to measure the distance from the child’s eyes to the card throughout testing. For 38 cm, the aid was the distance measured from the tester’s elbow to a specific knuckle on the tester’s hand, and for 55 cm, the aid was the length (55 cm) of the Teller Acuity Card. Testers were instructed to hold the cards without wrapping their fingers around the front side of the card, as this may attract the child’s attention. Testers presented the cards directly in front of the child and observed the child either over the top of the card or through the peephole in the card. During each acuity test, a masked visual acuity examiner was aware that the gratings were arranged in order from lower to higher spatial frequencies in half-octave steps, but were masked to the absolute spatial frequency of the grating on each card. The subset of spatial frequencies used for each test was selected according to a pseudorandom order from among three possible subsets of spatial frequencies for the subject’s age group. All three subsets for each age group included spatial frequencies known to be well above the threshold for that age group. To keep the visual acuity examiner masked to the absolute spatial frequency, the visual acuity examiner was not permitted to look at the front of the card to confirm the location of the grating. Instead, the visual acuity examiner asked an assistant to confirm the location of the grating on the card, after the visual acuity examiner had shown a card to the subject enough times to assess whether or not the subject could detect the grating. A clinical examiner was masked to the acuity results and the assigned patient group. Acuity was scored as the spatial frequency of the finest grating and was converted to log values before data analysis. We used a handheld auto-refractometer (PlusoptiX A09, OptiMed, Sydney, Australia) to evaluate the function of the regenerated lenses according to the manufacturer’s methods. Descriptive statistics was provided for the primary and secondary endpoints measured by intervention groups at each time point. Mean and standard deviation was reported for continuous variables and count and percentage is reported for categorical variables. To assess whether the primary outcome, decimal acuity, was significantly improved within each group, we performed the pre-post comparison between decimal acuity measured at baseline and study endpoint using paired t-tests. Normality of the data was checked and non-parametric alternatives, Wilcoxon signed-rank test is considered if the assumption was severely violated. To evaluate whether the mean response profiles in two groups were similar, we used the linear mixed-effect model taking account for the within-subjects correlation. The baseline decimal acuity was not adjusted by the model due to the homogeneity of this measurement as shown in the summary statistics. As the standard-of-care approach requires laser surgery at 3 months while the novel treatment does not, we fit two models using before and after laser surgery data, separately, to demonstrate the superiority of the novel approach. In each model, the outcome is the decimal acuity measured at four time points: baseline, 1 week, 3 months (before or after laser surgery) and 6 months; time (baseline as the reference level), treatment assignment and their interaction are the fixed effects; and patient is the random effect. Significant associations are identified using likelihood ratio test (LRT) by comparing models with and without a fixed effect. A linear mixed-effect model is fit again by dropping out the insignificant fixed effect until the final model is selected. A contrast test is performed when necessary. For the secondary aim, we compared the proportions of each condition of complications between two groups. We assumed the occurrence of complications for eyes from the same patient were independent. The mean difference and its 95% confidence interval was reported. A two-proportion z-test was used with the nonparametric χ2 test as alternative if the normality assumption was violated. All tests were two-sided and a P value less than 0.05 is considered to be statistically significant. Accommodative response was measured by an open-field autorefractor (SRW-5001K; Shin-Nippon, Tokyo, Japan), which allows targets to be viewed at any distance. The paediatric patients were positioned for autorefractor measurement with assistance from their parents. The patients were guided to fixate binocularly at a near target (33 cm, 5 × 5 array of smiley faces of N10 size) and a far target (3 m, 5 × 5 array of smiley faces of N10 size) by a trained and certified investigator or study coordinator. The measurements from non-cycloplegic autorefraction were performed three times at each target distance by the same trained and certified investigator throughout the study, in order to maintain accuracy and consistency throughout the trial. Measurements were taken in the same quiet environment with consistent room illumination to diminish the influence of distracting factors and to maintain subjects’ concentration. The spherical equivalent refractive value (SER) was recorded for each measurement and the mean value was calculated for evaluation of an accommodative response. The value of accommodative response was the difference between SER values for the near and the far target. We also used dynamic retinoscopy to measure the infants’ accommodation29, 30, 31. In brief, we recorded a lens dioptre value using retinoscopy when a patient was guided to fixate on a target 3 m away. Then another lens dioptre value was recorded when the target was moved closer, at a distance of 33 cm from the eyes. The difference between these two measurements was used to evaluate lens accommodative power.

Liu R.,Zhongshan Ophthalmic Center | Li J.,Zhongshan Ophthalmic Center | Li Z.,Zhongshan Ophthalmic Center | Yu S.,Zhongshan Ophthalmic Center | And 5 more authors.
Retina | Year: 2016

Purpose: To investigate the sensitivity and specificity of spectral domain optical coherence tomography in distinguishing polypoidal choroidal vasculopathy (PCV) from typical neovascular age-related macular degeneration (nAMD). Methods: One hundred and eighty-eight eyes in 156 patients with active PCV or typical nAMD were enrolled prospectively. Three spectral domain optical coherence tomography manifestations, pigment epithelium detachment, double-layer sign, and thumb-like polyps were estimated in all the eyes. A diagnostic test to differentiate PCV from nAMD based on spectral domain optical coherence tomography was performed. Furthermore, the sensitivity and specificity was validated in a retrospective series of patients. Results: Pigment epithelium detachment, double-layer sign, and thumb-like polyps were more common in PCV eyes than in nAMD eyes. When the cutoff point was set as at least 2 positive signs out of 3 in the diagnostic test, the sensitivity was 89.4% and specificity was 85.3%. The results of the validation test further confirmed the strategy, with satisfying sensitivity (87.5%) and specificity (86.2%). Conclusion: Spectral domain optical coherence tomography is sensitive and specific in distinguishing PCV from nAMD. From these results, the presence of at least two out three signs (pigment epithelium detachment, double-layer sign, and thumb-like polyps) indicates a positive test and is therefore suggested to be the screening strategy for PCV.

Tan X.,Nanjing Medical University | Tan X.,Zhongshan Ophthalmic Center | Tan X.,Jiangsu Institute of Nuclear Medicine | Tan X.,University of Sydney
Eye (London, England) | Year: 2014

PURPOSE: To determine the levels of Th17-associated cytokines, particularly interleukin (IL)-17 and IL-22 in tears of patients with dry eye syndrome.METHODS: Tear samples were collected from 20 healthy volunteers, 20 dry eye (DE) patients with non-Sjögren's syndrome (NSSDE) and 20 DE patients with Sjögren's syndrome (SSDE). Symptom questionnaire was self-administered and multiple dry eye disease (DED)-related clinical tests were performed. The levels of IL-17 and IL-22 in tears were measured by enzyme-linked immunosorbent assay.RESULTS: The levels of IL-17 and IL-22 were significantly increased in tears of DE patients compared with those of controls and also higher in SSDE patients compared with those of NSSDE patients (P<0.05). Moreover, the levels of IL-17 and IL-22 were positively correlated with questionnaire score and keratopathy score but negatively correlated with tear film break-up time and Schirmer I test in both NSSDE and SSDE patients (P<0.05).CONCLUSIONS: The levels of IL-17 and IL-22 in tears were significantly increased in DE patients, which were associated with the disease severity. Therefore, Th17 cell-associated cytokines, particularly IL-17 and IL-22, may have important roles in the immunopathogenesis of the DED.

Li J.,Zhongshan Ophthalmic Center | Hess R.F.,McGill University | Chan L.Y.L.,Zhongshan Ophthalmic Center | Chan L.Y.L.,Hong Kong Polytechnic University | And 4 more authors.
Optometry and Vision Science | Year: 2013

PURPOSE: We have recently described a rapid technique for measuring suppression using a dichoptic signal/noise task. Here, we report a modification of this technique that allows for accurate measurements to be made in amblyopic patients with high levels of anisometropia. This was necessary because aniseikonic image size differences between the two eyes can provide a cue for signal/noise segregation and, therefore, influence suppression measurement in these patients. METHODS: Suppression was measured using our original technique and with a modified technique whereby the size of the signal and noise elements was randomized across the stimulus to eliminate size differences as a cue for task performance. Eleven patients with anisometropic amblyopia, five with more than 5 diopters (D) spherical equivalent difference (SED), six with less than 5 D SED between the eyes, and 10 control observers completed suppression measurements using both techniques. RESULTS: Suppression measurements in controls and patients with less than 5 D SED were constant across the two techniques; however, patients with more than 5 D SED showed significantly stronger suppression on the modified technique with randomized element size. Measurements made with the modified technique correlated with the loss of visual acuity in the amblyopic eye and were in good agreement with previous reports using detailed psychophysical measurements. CONCLUSIONS: The signal/noise technique for measuring suppression can be applied to patients with high levels of anisometropia and aniseikonia if element size is randomized. In addition, deeper suppression is associated with a greater loss of visual acuity in patients with anisometropic amblyopia. Copyright © 2013 American Academy of Optometry.

Chen Y.,Ophthalmic Research Institute | Lan W.,Ophthalmic Research Institute | Lan W.,Zhongshan Ophthalmic Center | Schaeffel F.,Ophthalmic Research Institute
Vision Research | Year: 2015

When the eye is covered with a filter that transmits light below 480. nm and a blue field is observed on a computer screen that is modulated in brightness at about 1. Hz, the fovea is perceived as small irregular dark spot. It was proposed that the "foveal blue scotoma" results from the lack of S-cones in the foveal center. The foveal blue scotoma is highly variable among subjects. Possible factors responsible for the variability include differences in S-cone distribution, in foveal shape, and in macular pigment distribution. Nine young adult subjects were instructed to draw their foveal blue scotomas on a clear foil that was attached in front of the computer screen. The geometry of their foveal pit was measured in OCT images in two dimensions. Macular pigment distribution was measured in fundus camera images. Finally, blue scotomas were compared with Maxwell's spot which was visualized with a dichroic filter and is commonly assumed to reflect the macular pigment distribution. The diameters of the foveal blue scotomas varied from 15.8 to 76.4. arcmin in the right eyes and 15.5 to 84.7. arcmin in the left and were highly correlated in both eyes. It was found that the steeper the foveal slopes and the narrower the foveal pit, the larger the foveal blue scotoma. There was no correlation between foveal blue scotoma and macular pigment distribution or Maxwell's spot. The results are therefore in line with the assumption that the foveal blue scotoma is a consequence of the lack of S-cones in the foveal center. Unlike the foveal blue scotoma, Maxwell's spot is based on macular pigment as previously proposed. © 2014 Elsevier B.V.

Chu X.K.,U.S. National Institutes of Health | Meyerle C.B.,U.S. National Institutes of Health | Liang X.,Zhongshan Ophthalmic Center | Chew E.Y.,U.S. National Institutes of Health | And 2 more authors.
Age | Year: 2014

The contribution of DNA damage to the pathogenesis of age-related macular degeneration (AMD) has been reported. Recently, a genomewide association study detected the association of a single-nucleotide polymorphism (SNP) in RAD51B (rs8017304 A>G) with AMD. RAD51B is involved in recombinational repair of DNA double-strand breaks. We analyzed RAD51B influence on AMD using two cohorts from Caucasian and Han Chinese populations. The Caucasian set replicated the rs8017304 A>G association and revealed two novel AMD-associated SNPs in RAD51B, rs17105278 T>C and rs4902566 C>T. Under the dominant model, these two SNPs exhibit highly significant disease risk. SNP-SNP interaction analysis on rs17105278 T>C and rs4902566 C>T homozygous demonstrated a synergistic effect on AMD risk, reaching an odds ratio multifold higher than well-established AMD susceptibility loci in genes such as CFH, HTRA1, and ARMS2. Functional study revealed lower RAD51B mRNA expression in cultured primary human fetal retinal pigment epithelium (hfRPE) carrying rs17105278 T>C variants than in hfRPE carrying rs17105278 wild type. We concluded that the risk of developing AMD exhibits dose dependency as well as an epistatic combined effect in rs17105278 T>C and rs4902566 C>T carriers and that the elevated risk for rs17105278 T>C carriers may be due to decreased transcription of RAD51B. This study further confirms the role of DNA damage/DNA repair in AMD pathogenesis. © 2014 American Aging Association.

Zhongshan Ophthalmic Center | Date: 2012-03-29

A transformable bed for examinations in pediatric ophthalmology, especially suitable for the use of general anesthesia when conducting eye examinations, is provided. The bed may include a fixed bed board, a movable bed board, a movable seat, a movable support, a securing strap, and a main frame. The bed may be fixedly connected to the top of the main frame, the movable bed board may be rotationally connected to the top of the main frame, and the movable seat may be rotationally connected to the top of the main frame. The securing strap may be disposed on the movable bed board, in which one end of the movable support may be removably connected to the movable bed board, and another end may be removably connected to the main frame. The transformable bed may function both as an anesthesia bed and a handcart, and may be quickly switched therebetween.

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