An Enhancement on Convolutional Artificial Intelligent Based Diagnosis for Skin Disease Using Nanotechnology Sensors.

Skin disease is the major health problem around the world. The diagnosis of skin disease remains a challenge to dermatologist profession particularly in the detection, evaluation, and management. Health data are very large and complex due to this processing of data using traditional data processing techniques is very difficult. In this paper, to ease the complexity while processing the inputs, we use multilayered perceptron with backpropagation neural networks (MLP-BPNN). The image is collected from the devices that contain nanotechnology sensors, which is the state-of-art in the proposed model. The nanotechnology sensors sense the skin for its chemical, physical, and biological conditions with better detection specificity, sensitivity, and multiplexing ability to acquire the image for optimal classification. The MLP-BPNN technique is used to envisage the future result of disease type effectively. By using the above MLP-BPNN technique, it is easy to predict the skin diseases such as melanoma, nevus, psoriasis, and seborrheic keratosis.

Performance in the Duke-Elder ophthalmology undergraduate prize examination and future careers in ophthalmology.

AIMS: Cognitive factors (eg, academic achievement) have had a significant role in selecting postgraduate surgical trainees in the past. This project sought to determine the role of a national undergraduate ophthalmology prize examination (Duke-Elder examination) in the selection of postgraduate ophthalmology trainees. This would also serve as a quality assurance exercise for the assessment, in which the ultimate aim is to encourage trainees into ophthalmology. METHODS: A retrospective analysis of the top 20 ranked candidates in the Duke-Elder examination from 1989 to 2005 (except 1995) was carried out to determine which of them subsequently entered the ophthalmic training and General Medical Council Specialist Registers. RESULTS: Out of the top 20 candidates in the exam, 29.5% went into specialist training in ophthalmology. Some appeared in the top 20 more than once, with 56% of them going into ophthalmic training, but they had a similar median time to enter training as those who appeared in the top 20 once. There was no significant evidence to suggest that the overall median ranking scores between the UK medical schools differed (P=0.23; Kruskal-Wallis test). However, there was a marked difference in frequency of top 20 candidates from each medical school, which could not be explained by the size of the medical school alone. CONCLUSION: It is difficult to conclude from these findings the importance that the Duke-Elder examination has in the selection of trainees into ophthalmology. The role of cognitive factors in selection into postgraduate medical/surgical training is discussed, along with the potential academic criteria, which may influence interview scores.

Tacrolimus immunosuppression in high-risk corneal grafts.

BACKGROUND: Unlike the immune privilege enjoyed by low-risk corneal grafts, high-risk corneal grafts experience rejection rates comparable to liver and kidney transplants. Systemic immunosuppression reduces the risk of rejection in high-risk corneal grafts. METHODS: Systemic tacrolimus, a specific T cell inhibitor, was used at a mean daily dose of 2.5 mg to immunosuppress 43 patients undergoing high-risk corneal transplantation. Immunosuppression was continued for a period of 18-24 months after the high-risk corneal graft. RESULTS: During a mean follow-up period of 33.7 months, clarity of the graft was maintained in 65% of patients. Eight patients experienced rejection episodes while on tacrolimus, and this led to graft failure in five patients. CONCLUSION: Tacrolimus is relatively safe and effective in reducing rejection and prolonging graft survival in patients with high-risk keratoplasty compared with other series where similar immunosuppression was not used.

Epithelial proliferative potential of organ cultured corneoscleral rims; implications for allo-limbal transplantation and eye banking.

AIMS: To determine the epithelial proliferative capacity of organ cultured limbal tissue and correlate this with various donor and eye banking factors. METHODS: 24 corneoscleral limbal (CSL) rims left over from penetrating keratoplasty were split in half and set up as in vitro explant cultures. Corneal epithelial proliferative potential (CEPP) was assessed by the number of "cycles" of growth achieved before explants underwent exhaustion and failure to generate an epithelium to subconfluence. The dependence of CEPP on the age of the donor, time of death to enucleation, time of enucleation to organ culture, and time in organ culture in the eye bank was determined. RESULTS: CSL rims were capable of up to four cycles of culture with a wide variation between tissue samples. Of the various factors examined, death to enucleation time was the only statistically significant factor affecting the CEPP (regression coefficient: -0.062 (cycles/hour), CI -0.119 to -0.004, p = 0.037). Time in organ culture had little effect on CEPP. CONCLUSIONS: Preselected organ cultured CSL rims from eye banks may offer a viable alternative tissue source for use in allo-limbal transplantation.

The efficacy of sirolimus in the treatment of patients with refractory uveitis.

AIMS: To determine the efficacy of sirolimus in the treatment of patients with severe non-infectious uveitis. METHODS: Eight patients with severe non-infectious uveitis were recruited to an open study. Inclusion criteria were limited to patients whose disease was not controlled with at least two or more separate steroid sparing immunosuppressants (either because of unacceptable side effects or ineffectiveness of the drug) or who required regular doses of corticosteroids either as high dose systemic or orbital floor injections in order to control their disease. Intraocular inflammation, visual acuity, symptoms, corticosteroid burden, drug toxicity, and side effects were monitored. RESULTS: Sirolimus therapy was effective in five of the eight patients, all of whom had their dose of corticosteroids reduced or discontinued. Treatment in three patients was considered a failure as it caused intolerable side effects and/or failed to control the uveitis. Side effects were common and were typically gastrointestinal or cutaneous in nature. The severity of symptoms was dose dependent in most cases and occurred at trough blood levels above 25 ng/ml. CONCLUSION: Sirolimus is an effective and potent immunosuppressive treatment in the majority of patients with non-infectious uveitis and can reduce the need for long term supplementary corticosteroid therapy. Further studies are required to establish the long term efficacy and safety of sirolimus alone or in combination with other steroid sparing immunosuppressants.

Limbal epithelial crypts: a novel anatomical structure and a putative limbal stem cell niche.

BACKGROUND/AIMS: There is substantial evidence that mammalian epithelial stem cells are located within well defined niches. Although the corneoscleral limbus is acknowledged as the site of corneal epithelial stem cells no anatomical niche for such cells has yet been described. The authors undertook to re-evaluate the microanatomy of the limbus in order to identify possible sites that may represent a stem cell niche. METHODS: Systematic serial 5-7 microm sections of human corneoscleral segments obtained from cadaver donors, were examined. The sections were stained with haematoxylin and eosin or toludine blue. Sections with specific areas of interest were further examined immunohistologically for the corneal epithelial marker cytokeratin 14 and the "stem cell" marker ABCG2 transporter protein. RESULTS: Distinct anatomical extensions from the peripheral aspect of the limbal palisades were identified. These consist of a solid cord of cells extending peripherally or circumferentially. The cells stained positive for CK14 and ABCG2. CONCLUSIONS: A novel anatomical structure has been identified at the human limbus, which demonstrates characteristics of being a stem cell niche. The authors have termed this structure the limbal epithelial crypt.

The effect of lens design on dysphotopsia in different acrylic IOLs.

PURPOSE: To compare the incidence and severity of all grades of dysphotopsia in three types of acrylic intraocular lenses: the Acrysof MA30 BA and MA60 BM IOLs (Alcon) and the Akreos Fit one-piece IOL (Bausch and Lomb). METHODS: In all 111 patients were prospectively recruited who had undergone uncomplicated cataract surgery in the previous 12 months. Patients were assessed using a combination of a questionnaire and standardised provocation test, and were scored on a grading scale of 0-6 (0 indicating no glare and 6 indicating the most severe symptoms). RESULTS: The overall incidence of dysphotopsia was 77.7%. Patients with absent or mild symptoms (scoring 2 or less on the grading scale) were greater in the group implanted with the Akreos IOLs (49/65 eyes, 75%) as opposed to (44/92 eyes, 48%) of the eyes implanted with Acrysof lenses. Patients with more marked symptoms of glare as judged by scores of 5-6 were uncommon, but more prevalent in the Acrysof lenses (12/92 eyes, 13%) compared to the Akreos lenses (3/65 eyes, 4.6%) respectively. Statistically the Mann-Whitney test showed that there was significantly less dysphotopsia with the Akreos lens when compared to the Acrysof MA30 (P=0.005) and MA60 lenses (P=0.002). CONCLUSION: This study demonstrates that dysphotopsia symptoms are commonly seen in certain brands of Acrylic IOLs. However, differences in design (not only related to the edge) significantly reduce the incidence of moderate and severe grades of dysphotopic symptoms.

External ocular infections due to methicillin-resistant Staphylococcus aureus (MRSA).

PURPOSE: To determine the prevalence and clinical characteristics of external ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA) in an ophthalmic hospital in the UK. METHODS: A retrospective analysis of the case notes of patients who had culture proven external ocular Staphylococcal infections during a 44-month period was undertaken. RESULTS: There were a total of 548 external eye infections caused by Staphylococcus aureus. Of these, 17 (3%) were MRSA positive. The most common presentation was conjunctivitis seen in six patients. All MRSA isolates were sensitive to chloramphenicol. Ofloxacin resistance was observed in all isolates from patients over the age of 50 years. All patients had an underlying history of either an ocular surface disease, malignancy, or a debilitating medical illness. CONCLUSIONS: MRSA is as yet an infrequent cause of external ocular infections. Patients typically have underlying ocular risk factors and/or are medically debilitated. Different strains infect young and old age groups with characteristic antimicrobial sensitivity. This study highlights the need for more work to establish the role of MRSA commensals and ocular infections.

Epithelial cell characteristics of cultured human limbal explants.

AIM: To determine the immunohistochemical characteristics of putative corneal epithelial stem cells remaining on limbal explants maintained in culture. METHODS: Human limbal explant cultures were generated from 25 residual corneoscleral donor rims following penetrating keratoplasty. Serial sections of these explants were studied using immunohistochemical techniques with a panel of antibodies, on day 0 and 1, 2, and 3 weeks. RESULTS: The number of epithelial cells expressing cytokeratin 19 and vimentin increased with duration in culture, while the number of cells expressing cytokeratin 3 decreased. Connexin 43 expression was lost by 1 week in culture. p63 was expressed by cells that had migrated around the explant and the number of p63 positive cells decreased with longer duration in culture. The explants were initially negative for Ki67, but the epithelial cells were positive at 1 week, and expression of Ki67 was progressively lost with increasing duration in culture. The initial uniform staining of the epithelium for epidermal growth factor receptor and alpha enolase remained unchanged at 3 weeks. CONCLUSIONS: There is an expansion of less differentiated (cytokeratin 3 negative and CK19/vimentin positive) epithelial cells on corneoscleral explants maintained in culture for 3 weeks. The pattern of expression of p63 noted in this study does not support the suggestion that it is a marker of limbal stem cells. The decline in p63 and Ki67 expression among the epithelial cells of the cultured explant button implies that as the epithelial sheet outgrowing from the explant button reaches confluence, the proliferative status of the cells remaining on the explant button declines. These findings are of clinical relevance as explants of limbal tissue are used in limbal stem cell transplantation. There is no information available to date on the fate of epithelial cells on such explants. This study provides some insight into this and suggests that an expansion of the stem cell pool or its progeny may occur in limbal explants.

Stem cell differentiation and the effects of deficiency.

Stem cells have several unique attributes, the key features being their potency and plasticity. They have the ability to give rise to multiple cell lineages and to transdifferentiate into totally different cell type(s) when relocated to a novel stem cell niche. Most self-renewing tissues are served by stem cells. At the ocular surface, the corneo-scleral limbus is believed to provide the niche for corneal epithelial stem cells. A large body of circumstantial evidence, both clinical and basic, supports this view. However, specific identification of limbal stem cells has proved elusive. Cytokeratin markers, vimentin, epidermal growth factor receptors, p63, and others have been used to identify epithelial cell populations at the limbus, which could harbour putative stem cells. In contrast, none of the known haematopoietic stem cell markers namely, CD34 and CD133, stain any specific subset of corneal or limbal epithelial cells. Singly or collectively, none of these markers point to any unique cell(s) that could be regarded as stem cells, supporting the notion that the corneal epithelium is served by 'committed progenitors' rather than by stem cells. Disease or destruction of the corneo-scleral limbus is associated with consequential events that eventually lead to visual impairment or blindness. Conjunctivalisation and vascularisation of the corneal surface and persistent or recurring epithelial defects are hallmarks of limbal deficiency.