Flashes, floaters, and retinal detachment

Patients presenting to the family physician and ophthalmologist often have complaints of flashes and floaters. These symptoms may be benign or they may be associated with serious conditions such as a retinal tear or retinal detachment. Recognizing the importance of these symptoms would allow prompt referral to the ophthalmologist for a detailed ocular examination. Today, more than 95% of retinal detachments can be successfully treated, although more than one procedure may be required. Prevention or early diagnosis is important because the rate of successful repair is higher and the visual results are better if the retinal detachment spares the macula, the part of the retina responsible for fine, central vision. Through successful treatment, patients will be able to enjoy a better quality of life and maintain their abilities to read, work, drive, and care for themselves.published_or_final_versio

Chloroquine-induced bull's eye maculopathy

We report the case of a 51-year-old woman who presented with bilateral progressive deterioration in vision after taking chloroquine for severe rheumatoid arthritis for 10 years. She was found to have a bull's eye pattern of depigmentation in the macula of both eyes. Despite cessation of chloroquine, her vision did not improve. The clinical presentation of chloroquine retinopathy is discussed, along with the importance of scheduled eye examination for individuals taking chloroquine or hydroxychloroquine.published_or_final_versio

Enucleation of painful blind eye for refractory intraocular lymphoma after dose-limiting chemotherapy and radiotherapy

published_or_final_versionSpringer Open Choice, 25 May 201

Rhein Induced Apoptosis through the Endoplasmic Reticulum Stress, Caspase- and Mitochondria-dependent Pathways in SCC-4 Human Tongue Squamous Cancer Cells

[[abstract]]Rhein, an anthraquinone compound, can be found in the rhizome of rhubarb, a traditional Chinese medicine herb showing antitumor activity. In this study, it was observed that rhein induced S-phase arrest through the inhibition of p53, cyclin A and E and it induced apoptosis through the endoplasmic reticulum stress by the production of reactive oxygen species (ROS) and Ca2+ release, mitochondrial dysfunction, and caspase-8, -9 and -3 activation in human tongue cancer cell line (SCC-4). The most efficient induction of apoptosis was observed at 30 mu M for 24 h. Mechanistic analysis demonstrated that rhein induced changes in the ratio of Bax/Bcl-2 based on the decrease of Bcl-2 levels, the loss of mitochondrial membrane potential, cytochrome c release from the mitochondria and the activation of caspase-9 and -3. The data demonstrated that rhein induces apoptosis in SCC-4 cells via caspase, ROS and mitochondrial death pathways

Simultaneous spectral domain OCT and fundus autofluorescence imaging of the macula and microperimetric correspondence after successful repair of rhegmatogenous retinal detachment

Background/aims: To evaluate the ultrastructural changes in the macula after successful repair of rhegmatogenous retinal detachment (RRD) using simultaneous spectral domain optical coherence tomography (sdOCT) and fundus autofluorescence (FAF) imaging and to perform functional correlations with microperimetry. Methods: Simultaneous sdOCT and FAF imaging were performed using a combined sdOCT-confocal scanning laser ophthalmoscope (cSLO) system. Microperimetry was performed in a subgroup of these patients. Results: 17 patients with macular-on RRD and 20 with macular-off RRD were recruited. sdOCT images revealed disruption of the external limiting membrane, inner segment/outer segment junction or the Verhoeff membrane in 16 eyes (43.2%). The presence of any or more of these disruptions was significantly associated with a poor postoperative best-corrected visual acuity (BCVA) (p<0.001). Patients with abnormal FAF were also associated with poor postoperative BCVA (p<0.001). However, there was a generally poor correspondence between the localisation of ultrastructural abnormalities as detected by sdOCT and FAF changes. Areas of decreased microperimetric sensitivity corresponded well with the ultrastructural changes and abnormal FAF. Conclusions: FAF changes may lag behind ultrastructural changes in the OCT, some of which may reverse with the passage of time. The present study demonstrates the ultrastructural changes assessed with simultaneous FAF and sdOCT and their relation with visual outcome.published_or_final_versio

Development of a Chinese version of the National Eye Institute Visual Function Questionnaire (CHI-VFQ-25) as a tool to study patients with eye diseases in Hong Kong

Background: To develop a Chinese version of the National Eye Institute Visual Function Questionnaire (CHI-VFQ-25) and to test its reliability and validity in a group of patients with eye diseases in Hong Kong. Methods: The National Eye Institute Visual Function Questionnaire (NEI-VFQ) was translated into Chinese. Patients were recruited from Hong Kong, and their demographic data and visual acuity were documented. Psychometric properties of the CHI-VFQ-25, including internal consistency, test-retest reliability, item-scale correlations and construct validity were tested. Results: 250 patients were recruited. The mean age of the patients was 66.04 (SD 14.00). 46% of them were male. The non-response rate and the floor and ceiling numbers of the CHI-VFQ-25 were calculated. The internal consistency was high in most subscales (except the general health and driving subscales), with Cronbach α ranging from 0.72-0.90. The test-retest reliability was excellent (intraclass correlation coefficient >0.90). Patients with worse visual acuity had significantly lower scores on the CHI-VFQ-25 supporting construct validity. Conclusion: The CHI-VFQ-25 is a reliable and valid tool for assessing the visual functions of Chinese patients with eye diseases in Hong Kong. Some questions had high non-response rates and should be substituted by the available alternatives.published_or_final_versio

Digital evidence search kit

With the rapid development of electronic commerce and Internet technology, cyber crimes have become more and more common. There is a great need for automated software systems that can assist law enforcement agencies in cyber crime evidence collection. This paper describes a cyber crime evidence collection tool called DESK (Digital Evidence Search Kit), which is the product of several years of cumulative efforts of our Center together with the Hong Kong Police Force and several other law enforcement agencies of the Hong Kong Special Administrative Region. We will use DESK to illustrate some of the desirable features of an effective cyber crime evidence collection tool. © 2005 IEEE.published_or_final_versio

Bandit Models of Human Behavior: Reward Processing in Mental Disorders

Drawing an inspiration from behavioral studies of human decision making, we propose here a general parametric framework for multi-armed bandit problem, which extends the standard Thompson Sampling approach to incorporate reward processing biases associated with several neurological and psychiatric conditions, including Parkinson's and Alzheimer's diseases, attention-deficit/hyperactivity disorder (ADHD), addiction, and chronic pain. We demonstrate empirically that the proposed parametric approach can often outperform the baseline Thompson Sampling on a variety of datasets. Moreover, from the behavioral modeling perspective, our parametric framework can be viewed as a first step towards a unifying computational model capturing reward processing abnormalities across multiple mental conditions.Comment: Conference on Artificial General Intelligence, AGI-1

Anode modification of polyfluorene-based polymer light-emitting devices

A glycerol-modified poly(3,4-ethylene dioxythiophene) (PEDOT): poly(styrene sulfonate) (PSS) layer was used as an anode buffer layer in polymer light-emitting devices using poly(9,9-dioctylfluorene) (F8) as the emitter. Devices with a configuration of indium tin oxide/PEDOT:PSS (with or without glycerol)/F8/CsF/Al were fabricated. It was found that the glycerol-modified device showed a much larger current density than the unmodified device. At an operating voltage of 6 V, the glycerol-modified device showed a luminance of 1300Cd/m 2 and a current efficiency of 1.7 Cd/A compared to the corresponding values of 500Cd/m 2 and 1.3 Cd/A in the unmodified device. Analysis by ultraviolet spectroscopy suggests that the two devices have the same energy level structure and the performance improvement should not be due to change in the PEDOT/polymer interface. It was further found that incorporating a suitable amount of glycerol into the PEDOT:PSS layer can increase its conductivity by six times. This leads to a better balance in the hole and electron currents and thus improved device efficiency. © 2002 American Institute of Physics.published_or_final_versio