Biometry of the cornea and anterior chamber in chinese eyes: an anterior segment optical coherence tomography study.

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.

Use of EyeCam for imaging the anterior chamber angle.

Purpose: To compare EyeCam (Clarity Medical Systems, Pleasanton, CA) imaging with gonioscopy for detecting angle closure.

Methods: In this prospective, hospital-based study, subjects underwent gonioscopy by a single observer and EyeCam imaging by a different operator. EyeCam images were graded by two masked observers.

Diurnal intraocular pressure fluctuation and associated risk factors in eyes with angle closure.

Objective: To investigate diurnal intraocular pressure (IOP) fluctuation in eyes with angle closure in comparison with normal subjects and to look for associated risk factors for IOP fluctuation.

Design: Prospective, cross-sectional study.

Participants: Ninety-eight eyes of 98 Asian subjects with angle closure (consisting of 32 primary angle-closure suspects [PACS], 34 subjects with primary angle closure [PAC], and 32 subjects with primary angle-closure glaucoma [PACG]) and 21 eyes of 21 normal control subjects.

Haemorrhagic pigment epithelial detachment as a predictive feature of polypoidal choroidal vasculopathy in a Chinese population.

Purpose: To determine the frequency of haemorrhagic pigment epithelial detachment (PED) among patients presenting with either polypoidal choroidal vasculopathy (PCV) or choroidal neovascularization (CNV) and calculate the degree to which the presence of a haemorrhagic PED can be used to predict the diagnosis of PCV.

Methods: A retrospective review of 290 eyes of 253 patients presenting to the Singapore National Eye Centre with serosanguineous maculopathy. Patients underwent ophthalmologic examination including digital colour fundus photography and stereoscopic fluorescein angiography and indocyanine green angiography (ICGA).

Tailoring the morphology of carbon nanotube arrays: from spinnable forests to undulating foams.

Directly spinning carbon nanotube (CNT) fibers from vertically aligned CNT arrays is a promising way for the application of CNTs in the field of high-performance materials. However, most of the reported CNT arrays are not spinnable. In this work, by controlling catalyst pretreatment conditions, we demonstrate that the degree of spinnability of CNTs is closely related to the morphology of CNT arrays.

Comparison of outcomes of lamellar keratoplasty and penetrating keratoplasty in keratoconus.

Purpose: To compare outcomes after penetrating keratoplasty (PK) and two techniques of deep anterior lamellar keratoplasty (DALK) in patients with keratoconus.

Design: Retrospective cohort study.

Methods: One hundred and twenty-five corneal transplantations comprising 100 PK and 25 DALK procedures for keratoconus at the Singapore National Eye Centre from April 1992 through December 2006 were included.

Diagnosis of tuberculous uveitis: clinical application of an interferon-gamma release assay.

Purpose: To determine the role of the QuantiFERON-TB Gold In-Tube (QFT) (Cellestis Inc., Carnegie, Australia) assay in the diagnosis of tuberculosis (TB) uveitis.

Design: Retrospective cohort study.

Comparison of Visante and slit-lamp anterior segment optical coherence tomography in imaging the anterior chamber angle.

Aims: To compare the diagnostic performance of two anterior segment optical coherence tomography (AS-OCT) devices in assessing the anterior chamber angle (ACA).

Methods: Visante-OCT and slit-lamp-OCT (SL-OCT) were performed on 101 patients by a single operator. The AS-OCT images were processed by customised 'dewarping' software and assessed by two glaucoma specialists masked to clinical findings.

Anomalous circular polarization of photoluminescence spectra of individual CdSe nanocrystals in an applied magnetic field.

We study the low-temperature magnetophotoluminescence from individual CdSe nanocrystals. Nanocrystals having a small "bright" exciton fine structure splitting (Delta_{XY}<0.5 meV) exhibit a conventional left and right circularly polarized Zeeman photoluminescence doublet in applied magnetic fields.

'Giant' multishell CdSe nanocrystal quantum dots with suppressed blinking: Novel fluorescent probes for real-time detection of single-molecule events.

We reported for the first time that key nanocrystal quantum dot (NQD) optical properties-quantum yield, photobleaching and blinking-can be rendered independent of NQD surface chemistry and environment by growth of a very thick, defect-free inorganic shell (Chen, et al. J. Am.

Outcomes of therapeutic deep lamellar keratoplasty and penetrating keratoplasty for advanced infectious keratitis: a comparative study.

Purpose: To compare the therapeutic success, visual outcomes, complications, and graft survival rates of therapeutic deep anterior lamellar keratoplasty (TDALK) and therapeutic penetrating keratoplasty (TPK) for advanced infectious keratitis.

Design: Retrospective, comparative study.

Participants: One hundred twenty-three patients (126 eyes) with medically uncontrolled infectious keratitis of bacterial, fungal, or acanthamoeba etiologies who underwent TDALK (n = 26) or TPK (n = 100 eyes; 80 nonperforated ulcers; 20 perforated ulcers; mean follow-up in TDALK, 12.

The singapore 5-Fluorouracil trabeculectomy study: effects on intraocular pressure control and disease progression at 3 years.

Purpose: To report 3-year results of a randomized, controlled trial comparing the use of a single application of 5-fluorouracil (5-FU) with placebo in trabeculectomy surgery.

Design: Prospective, randomized, double-blinded treatment trial.

Participants: Two hundred forty-three Asian patients with primary open-angle or primary angle-closure glaucoma undergoing primary trabeculectomy.

Variation of angle parameters in asians: an anterior segment optical coherence tomography study in a population of singapore malays.

Purpose: To assess variations in angle parameters using anterior segment optical coherence tomography (AS-OCT) and to investigate demographic, ocular and systemic associations of angle width.

Methods: This was a substudy of a population based, cross-sectional survey of 3280 (78.7% response rate) Malay people aged 40 to 80 years in Singapore.

Increased SPARC expression in primary angle closure glaucoma iris.

Purpose: SPARC (secreted protein, acidic, and rich in cysteine) is involved in extracellular matrix (ECM) organization. The purpose of this study was to evaluate the expression of SPARC in iris tissue from primary angle closure glaucoma (PACG) eyes.

Methods: Iris tissue was obtained from peripheral iridectomies performed during trabeculectomy surgery in nine PACG and 16 primary open-angle glaucoma (POAG) eyes at the Singapore National Eye Centre.

Direct observation of dark excitons in individual carbon nanotubes: inhomogeneity in the exchange splitting.

We report the direct observation of spin-singlet dark excitons in individual single-walled carbon nanotubes through low-temperature micro-magneto-photoluminescence spectroscopy. A magnetic field (B) applied along the tube axis brightened the dark state, leading to the emergence of a new emission peak. The peak rapidly grew in intensity with increasing B at the expense of the originally dominated bright exciton peak and became dominant at B>3 T.

Time-resolved photoluminescence of type-II Ga(As)Sb/GaAs quantum dots embedded in an InGaAs quantum well.

Optical properties and carrier dynamics in type-II Ga(As)Sb/GaAs quantum dots (QDs) embedded in an InGaAs quantum well (QW) are reported. A large blueshift of the photoluminescence (PL) peak is observed with increased excitation densities. This blueshift is due to the Coulomb interaction between physically separated electrons and holes characteristic of the type-II band alignment, along with a band-filling effect of electrons in the QW.

"Giant" multishell CdSe nanocrystal quantum dots with suppressed blinking.

Semiconductor nanocrystal quantum dots (NQDs) comprise an important class of inorganic fluorophores for applications from optoelectronics to biology. Unfortunately, to date, NQD optical properties (e.g.

Penetrating keratoplasty in Asian eyes: the Singapore Corneal Transplant Study.

Purpose: The Singapore Corneal Transplant Study (SCTS) is a 16-year prospective study of 2100 consecutive corneal transplants performed between January 1991 and November 2006 in patients from Southeast Asia at a single tertiary center. The indications, complications, long-term survival rates, and risk factors for graft failure of penetrating keratoplasty (PK) performed in Asian eyes are reported.

Design: Prospective cohort study.

Assessment criteria for compliance with oral hygiene: application of ROC analysis.

Purpose: Diabetes is an established risk factor for periodontal disease. Management of periodontal disease is highly dependent upon effective oral hygiene. Assessment of plaque and gingivitis has been commonly used and arbitrarily set in clinical practice to evaluate patients' adherence with oral hygiene recommendations.

Single carbon nanotubes probed by photoluminescence excitation spectroscopy: the role of phonon-assisted transitions.

We study light absorption mechanisms in semiconducting carbon nanotubes using low-temperature, single-nanotube photoluminescence excitation spectroscopy. In addition to purely electronic transitions, we observe several strong phonon-assisted bands due to excitation of one or more phonon modes together with the first electronic state. In contrast with a small width of emission lines (sub-meV to a few meV), most of the photoluminescence excitation features have significant linewidths of tens of meV.

Structure of excited-state transitions of individual semiconductor nanocrystals probed by photoluminescence excitation spectroscopy.

We perform for the first time photoluminescence excitation (PLE) studies of individual nanocrystals (NCs) that reveal the structure of excited-state transitions not obscured by ensemble averaging. Single-NC PLE spectra strongly deviate from a traditional idealized picture of sharp, quasiatomic resonances. We detect only a few relatively narrow transitions (3-4 meV) at the band edge, while at higher spectral energies, we observe a broad structureless feature separated from the band-edge peaks by a >50 meV "minigap.

Low temperature emission spectra of individual single-walled carbon nanotubes: multiplicity of subspecies within single-species nanotube ensembles.

Low-temperature photoluminescence (PL) studies of individual semiconducting single-walled carbon nanotubes reveal ultranarrow peaks (down to 0.25 meV linewidths) that exhibit blinking and spectral wandering. Multiple peaks appear within bands previously assigned to nanotubes of certain chiralities, indicating the existence of numerous subspecies within single-chirality specimens.

Effect of zero- to one-dimensional transformation on multiparticle Auger recombination in semiconductor quantum rods.

We study the effect of the zero- to one-dimensional (1D) transformation on multiparticle Auger recombination using a series of elongated semiconductor nanocrystals (quantum rods). We observe a transition from the three- to two-particle recombination process as the nanocrystal aspect ratio is increased. This transition indicates that in the 1D confinement limit, Auger decay is dominated by Coulomb interactions between 1D excitons that recombine in a bimolecular fashion.

Interplay of Rabi oscillations and quantum interference in semiconductor quantum dots.

We investigated the manifestation of Rabi oscillation in the coherent dynamics of excitons in self-assembled semiconductor quantum dots. The Rabi oscillation phenomenon was directly observed as a function of the input pulse area. Furthermore, by performing wave packet interferometry in the nonlinear excitation regime, we discover a new type of quantum interference phenomenon, resulting from the interplay between Rabi oscillation and quantum interference.

National oral health survey Zimbabwe 1995: periodontal conditions.

Ten years after completion of the first national oral health survey, a second national oral health survey was carried out in 1995. Application of a multi-stage sampling procedure resulted in 3,709 persons being examined. WHO's oral health assessment form and CPITN index was used.