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Emily Y Chew

Publications and source records attributed to Emily Y Chew.

27 records · Page 2Linked to original sources
PubMed2004

Von Hippel-Lindau gene deletion and expression of hypoxia-inducible factor and ubiquitin in optic nerve hemangioma.

PURPOSE: Von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome expressed in multiple organs caused by germline alterations of the VHL gene. We have shown VHL deletion in the "stromal" cells of retinal angiomas. The VHL protein-associated complex is a primary ubiquitin ligase for the ubiquitination of hypoxia-inducible factor (HIF). This study examines VHL and ubiquitin expression in optic nerve hemangiomas and juxtapapillary angiomas. METHODS: Using microdissection and polymerase chain reaction, four optic nerve hemangiomas (one also had juxtapapillary angioma) associated with VHL disease were analyzed for loss of heterozygosity in the VHL gene. In addition, expression of HIF and ubiquitin was evaluated in these tumors by immunohistochemistry. RESULTS: All informative optic nerve and juxtapapillary lesions showed loss of heterozygosity in the VHL gene detected in vacuolated "stromal" cells. Both HIF and ubiquitin were highly expressed in the hemangiomas of all four VHL cases. CONCLUSIONS: Like retinal angiomas and other VHL tumor lesions, VHL gene deletion is found in optic nerve hemangiomas and juxtapapillary angiomas. These tumor cells also express HIF and ubiquitin, the protein responsible for the negative regulation of HIF that results in the hypervascularization characteristic of VHL disease.

Adolescent↗
PubMed2003

von Hippel-Lindau disease.

von Hippel-Lindau disease is a heritable multisystem cancer syndrome that is associated with a germline mutation of the VHL tumour suppressor gene on the short arm of chromosome 3. This disorder is not rare (about one in 36000 livebirths) and is inherited as a highly penetrant autosomal dominant trait (ie, with a high individual risk of disease). Affected individuals are at risk of developing various benign and malignant tumours of the central nervous system, kidneys, adrenal glands, pancreas, and reproductive adnexal organs. Because of the complexities associated with management of the various types of tumours in this disease, treatment is multidisciplinary. We present an overview of the clinical aspects, management, and treatment options for von Hippel-Lindau disease.

von Hippel-Lindau Disease↗
PubMed2003

Effects of aldose reductase inhibitors and galactose withdrawal on fluorescein angiographic lesions in galactose-fed dogs.

OBJECTIVE: To assess the effect of aldose reductase inhibitor (ARI) M79175 (2-methyl-6-fluoro-spiro-chroman-4-5'-imidazolidine-2',4'-dione) administration and galactose withdrawal on the progression of retinal changes using fluorescein angiography in galactose-fed dogs. METHODS: Thirty male beagles were randomized into 4 groups. Three dogs were fed a normal control diet containing 30% nonnutritive fiber for 74 months (control group), 11 dogs a 30% galactose diet for 74 months (continuous galactose group), 8 dogs a 30% galactose diet for 36 months followed by replacement with a normal diet for 36 months (galactose withdrawal group), and 8 dogs a 30% galactose diet supplemented with M79175 for 34 months followed by replacement with a normal diet and removal of M79175 treatment for 38 months (ARI-treated galactose withdrawal group). Stereoscopic color fundus photography and fluorescein angiography, performed at baseline and follow-up, were assessed for the clinical development of retinopathy, including the first appearance of hyperfluorescence, varying severity of retinal nonperfusion, and retinal neovascularization. Histopathologic features were examined in selected dogs. RESULTS: All dogs in the 3 groups fed the 30% galactose diet developed areas of hyperfluorescence and nonperfusion. Of these dogs, only those supplemented with the ARI did not develop areas of nonperfusion greater than or equal to half the field and retinal neovascularization. Parametric survival analysis showed significant differences (galactose withdrawal group vs ARI-treated galactose withdrawal group) in the median times to the development of nonperfusion greater than or equal to half the field (P =.003) and retinal neovascularization (P =.03). CONCLUSION: Normalization of glycemic control with galactose withdrawal and ARI treatment may delay the onset and progression of retinal lesions in galactose-fed dogs. Clinical Relevance Perfect glycemic control after a period of poor control does not completely prevent the progression of retinal lesions. Therapy with ARIs may potentially be important in the prevention of retinal lesions associated with diabetic eye disease.

Aldehyde Reductase↗
PubMed2003

National Eye Institute Visual Function Questionnaire in the Age-Related Eye Disease Study (AREDS): AREDS Report No. 10.

OBJECTIVES: To describe the vision-targeted, health-related quality of life, measured with the National Eye Institute Visual Function Questionnaire (NEI-VFQ), in patients with age-related macular degeneration, cataract, or reduced visual acuity; to determine the relationship between the NEI-VFQ subscale scores and clinical measures of visual function; and to assess the internal consistency and reliability of the NEI-VFQ subscales. DESIGN: The 39-item NEI-VFQ was administered at the 5-year clinic visit to 4077 Age-Related Eye Disease Study participants. RESULTS: The subscales of the NEI-VFQ had moderate to high internal consistency (Cronbach's alpha = 0.58-0.91). The NEI-VFQ scores for participants with advanced age-related macular degeneration in 1 or both eyes, severe nuclear opacity, reduced visual acuity, or cataract surgery generally were lower than scores for disease-free participants (P<.001). CONCLUSION: These findings support the use of the NEI-VFQ as a measure of vision-targeted, health-related quality of life among patients with age-related macular degeneration, cataract, or reduced visual acuity.

Aged↗
PubMed2003

Histopathology and regression of retinal hard exudates in diabetic retinopathy after reduction of elevated serum lipid levels.

PURPOSE: To describe a regression of retinal hard exudates in 2 patients with diabetic maculopathy, and to report immunohistologic findings reflecting lipid deposition in the retina. DESIGN: Two interventional case reports. METHODS: Two patients with exudative diabetic maculopathy were treated to normalize serum lipids. Histologic examination and immunohistochemistry of each patient's eyes were performed to assess the localization of apolipoprotein B and cholesteryl ester, both of which are principal components of low-density lipoprotein. RESULTS: Both patients showed a dramatic regression of retinal hard exudates after correction of dyslipidemia. Histopathology revealed diffuse lipids and cholesteryl ester in the retina. Apolipoprotein B and macrophages were colocalized in the perivascular space. CONCLUSIONS: The regression of hard exudates was most likely due to the aggressive lipid lowering in both patients. The novel histopathologic findings of hard exudate and diabetic maculopathy are similar to the pathologic changes observed in larger atherosclerotic lesions, except that they occur in the intraretinal perivascular space.

Adult↗
PubMed2003

The long-term effects of laser photocoagulation treatment in patients with diabetic retinopathy: the early treatment diabetic retinopathy follow-up study.

OBJECTIVES: To evaluate the long-term natural history and effects of laser photocoagulation treatment in patients with diabetic retinopathy. DESIGN: Follow-up study of the 214 surviving patients enrolled originally at the Johns Hopkins Clinical Center for the Early Treatment Diabetic Retinopathy Study (ETDRS), which was a clinical trial designed to evaluate the role of laser photocoagulation and aspirin treatment in patients with diabetic retinopathy. METHODS: Early Treatment Diabetic Retinopathy Study patients enrolled in the Johns Hopkins Clinical Center had complete eye examinations, including best-corrected visual acuity measurements, fundus photographs, and medical questionnaires throughout the 7-year study. They had the same examinations at the final long-term follow-up visit at the National Eye Institute, National Institutes of Health, 13 to 19.5 years after the initial laser photocoagulation (median, 16.7 years). MAIN OUTCOME MEASURES: The major outcomes were mortality and the rates of moderate and severe vision loss. The secondary outcomes were progression of diabetic retinopathy and need for other eye surgery. RESULTS: Of the 214 patients who were alive at the end of the original ETDRS in 1989, 130 (61%) were deceased at the time of the re-examination. Of the 84 who were alive, 71 (85%) were examined at their long-term follow-up visit at the National Institutes of Health. At the long-term follow-up examination, 42% had visual acuity of 20/20 or better, and 84% had visual acuity of 20/40 or better in the better eye. Compared with baseline, 20% of patients had moderate vision loss (loss of 3 lines or more vision) in the better eye at follow-up. Only one patient had visual acuity of 20/200 bilaterally. He had visual acuity loss secondary to age-related macular degeneration. No patient had severe vision loss (worse than 5/200). All the initially untreated eyes of patients who had severe nonproliferative diabetic retinopathy or worse by the time of the ETDRS closeout visit of the original study received scatter photocoagulation treatment. Focal photocoagulation was performed in 43% bilaterally and 22% unilaterally. Cataract surgery was performed in 31% of the patients, vitrectomy in 17%, and glaucoma surgery in one patient. CONCLUSIONS: As previously reported, the mortality rate of patients with diabetic retinopathy is much higher than that of the general population. For those who survived, aggressive follow-up, with treatment when indicated, seems to be associated with maintenance of good long-term visual acuity for most patients. The need for laser scatter photocoagulation with long-term follow-up seems to be high.

Adult↗
PubMed2003

Epidemiology of diabetic retinopathy.

Diabetic retinopathy is associated with a number of systemic risk factors, namely hyperglycaemia, elevated blood pressure and dyslipidaemia. Patients with diabetes should be vigorously treated for these modifiable risk factors to prevent the development and progression of diabetic retinopathy.

Anemia↗
PubMed2002

Infantile cataract in the collaborative perinatal project: prevalence and risk factors.

OBJECTIVES: To estimate the prevalence of 4 categories of infantile cataract in subjects surviving the neonatal period in a US cohort, and to investigate risk factors for isolated infantile cataract. DESIGN: Prospective study of 55 908 pregnancies enrolled in the Collaborative Perinatal Project from 1959 to 1965 at 12 university medical centers. METHODS: We gathered data on demographic, lifestyle, and prenatal and perinatal obstetrical and postnatal factors using a standardized protocol. Pediatricians and neurologists examined infants at birth, 4 months, 1 year, and 7 years. We used exact logistic regression methods to compare putative risk factors in infants with isolated cataract with those in infants with no history of cataract. OUTCOME MEASURES: Infantile cataract as diagnosed using a standardized dilated ophthalmic examination. RESULTS: Infantile cataract occurred in 13.6 per 10 000 infants (95% confidence interval [CI], 10.7-17.1). Isolated infantile cataract occurred 3.8 times as often among infants born at weights at or below 2500 g than among those born at or above 2500 g (95% CI, 1.5-8.6; P<.001), after controlling for a set of covariates; we observed similar results for bilateral isolated cataract (odds ratio = 4.4; 95% CI, 1.2-13.9). No risk factor identified in bivariate analyses was independently associated with the odds of developing isolated unilateral infantile cataract. CONCLUSIONS: Infantile cataract is a rare disorder occurring during childhood. Prevalence estimates reported here are within the limits of those from large-cohort studies in economically developed nations. Infants born at weights at or below 2500 g have a 3- to 4-fold increased odds of developing infantile cataract.

Adult↗