Biomedical subjects

William V Good

Publications and source records attributed to William V Good.

28 records · Page 2Linked to original sources

PubMed2004

Conditional knockdown of tubedown-1 in endothelial cells leads to neovascular retinopathy.

PURPOSE: Identification of novel proteins involved in retinal neovascularization may facilitate new and more effective molecular-based treatments for proliferative retinopathy. Tubedown-1 (Tbdn-1) is a novel protein that shows homology to the yeast acetyltransferase subunit NAT1 and copurifies with an acetyltransferase activity. Tbdn-1 is expressed in normal retinal endothelium but is specifically suppressed in retinal endothelial cells from patients with proliferative diabetic retinopathy. The purpose of this study was to investigate the importance of Tbdn-1 expression in retinal blood vessels in vivo. METHODS: A bitransgenic mouse model that enables conditional knockdown of Tbdn-1 specifically in endothelial cells was produced and studied using molecular, histologic, and immunohistochemical techniques and morphometric analysis. RESULTS: Tbdn-1-suppressed mice exhibited retinal and choroidal neovascularization with intra- and preretinal fibrovascular lesions similar to human proliferative retinopathies. Retinal lesions observed in Tbdn-1-suppressed mice increased in severity with prolonged suppression of Tbdn-1. In comparison to normal retina, the retinal lesions displayed alterations in the basement membrane of blood vessels and in the distribution of glial and myofibroblastic cells. Moreover, the pathologic consequences of Tbdn-1 knockdown in endothelium were restricted to the retina and the choroid. CONCLUSIONS: These results indicate that the maintenance of Tbdn-1 expression is important for retinal blood vessel homeostasis and for controlling retinal neovascularization in adults. Restoration of Tbdn-1 protein expression and/or activity may provide a novel approach for treating proliferative retinopathies.

Acetyltransferases↗

PubMed2004

Final results of the Early Treatment for Retinopathy of Prematurity (ETROP) randomized trial.

PURPOSE: To present the final results of the Early Treatment for Retinopathy of Prematurity Study. METHODS: Infants with bilateral high-risk prethreshold retinopathy of prematurity (ROP) (n = 317) had one eye randomized to early retinal ablative treatment and the fellow eye managed conventionally (control eye). In asymmetric cases (n = 84), the eye with high-risk prethreshold ROP was randomized to early or to conventional management. High risk was determined using a model based on the Cryotherapy for Retinopathy of Prematurity natural history cohort. The primary outcome was visual acuity assessed by masked testers using the Teller acuity card procedure. Structural examinations were performed at 6 and 9 months. RESULTS: Grating acuity results showed a reduction in unfavorable visual acuity outcomes with earlier treatment, from 19.8% to 14.3% (P < .005). Unfavorable structural outcomes were reduced from 15.6% to 9.0% (P < .001) at 9 months. Further analysis supported retinal ablative therapy for eyes with type I ROP, defined as zone I, any stage ROP with plus disease; zone I, stage 3 ROP without plus disease; or zone II, stage 2 or 3 with plus disease. The analysis supported a "wait and watch" approach to type II ROP, defined as zone I, stage 1 and 2 without plus disease, or zone II, stage 3 without plus disease. These eyes should be considered for treatment only if they progress to type I ROP or threshold. CONCLUSION: Early treatment of high-risk prethreshold ROP significantly reduced unfavorable outcomes in both primary and secondary (structural) measures.

Cryosurgery↗

PubMed2003

Risk analysis of prethreshold retinopathy of prematurity.

OBJECTIVE: To present a new multifactorial algorithm to integrate important risk factors for unfavorable retinal outcome in eyes that reached prethreshold retinopathy of prematurity (ROP) in the Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. A computerized risk model (RM-ROP2) was developed from this algorithm to identify high-risk prethreshold eyes for enrollment in the Early Treatment for Retinopathy of Prematurity randomized trial. METHODS: Data were analyzed from 613 eyes (1 eye per infant) in the natural history cohort of the Multicenter Trial for Cryotherapy for Retinopathy of Prematurity. These eyes were selected from infants in whom 1 or both eyes progressed to prethreshold ROP. Eyes that progressed to threshold ROP and were randomized to cryotherapy were excluded from this study, but control eyes that reached threshold ROP were included. The course of ROP for 1 prethreshold eye for each infant was tracked until the evaluation of its structural outcome at 3 months' postterm. Tables present structural outcome by selected risk characteristics. A multiple logistic risk model is used to summarize the combined effect of all of these known prognostic risk factors as they relate to structural outcome. RESULTS: Eyes were classified by predicted outcome into 10 risk categories, lowest to highest. Both the observed and predicted outcomes in each category showed an increasingly unfavorable outcome when viewed from lowest to highest risk. Prethreshold ROP eyes were then divided into 2 groups, high-risk, eyes (risk, 0.15-1.0) and low-risk eyes (risk, <0.15). High-risk eyes had an unfavorable outcome of 36% at 3 months' postterm; whereas, only 5% of the low-risk eyes had an unfavorable outcome. CONCLUSION: The model effectively identifies prethreshold ROP eyes that have a relatively high risk and eyes that have a lower risk of an unfavorable structural outcome at 3 months.

Algorithms↗

PubMed2003

Herpes zoster virus sclerokeratitis and anterior uveitis in a child following varicella vaccination.

PURPOSE: To report a case of herpes zoster virus sclerokeratitis with anterior uveitis following vaccination with live attenuated varicella vaccine (Oka strain). DESIGN: Case report. METHODS: The case records of the patient were reviewed retrospectively. Pertinent literature citations were identified using MEDLINE. RESULTS: A 9-year-old boy presented with herpes zoster ophthalmicus 3 years following vaccination with live attenuated varicella vaccine (Oka strain). Examination of the affected eye revealed a moderate follicular response on the palpebral conjunctiva, decreased corneal sensation, mildly elevated intraocular pressure, diffuse anterior scleritis with marginal keratitis, and a moderately severe anterior uveitis. Amplified DNA from fluid taken from the base of a cutaneous vesicle produced wild-type varicella zoster virus (VZV) DNA, not Oka strain. CONCLUSIONS: Herpes zoster virus infection needs to be considered in all patients who present with scleritis, keratitis, or anterior uveitis, regardless of their varicella vaccination status.

Acyclovir↗

PubMed2003

Transient, idiopathic nystagmus in infants.

The aim of this study was to characterize children with transient nystagmus. Eleven children (six males, five females) developed nystagmus in infancy and then experienced regression of the problem, usually within a few months. Mean age at onset was 2.7 months, and mean age at regression was 8.5 months. No etiology could be ascertained in any of the patients, although four children had other eye or vision abnormalities (regressed retinopathy of prematurity, n=1; asymmetric fundus colobomata, n=1; delayed visual maturation, n=2). Results of this study suggest that mechanisms which allow ocular motor stability undergo a period of postnatal maturation, during which nystagmus can occur, but also during which nystagmus may disappear. Not every case of transient nystagmus should be categorized as spasmus nutans. There is a subset of infants and young children who develop transient nystagmus with no other findings and in whom the nystagmus disappears.

Age of Onset↗

PubMed2003

Conscious visual abilities in a patient with early bilateral occipital damage.

A 21-year-old male presented with occipital lobes that were extensively damaged by bilateral infarcts present at birth. The absence of the striate cortex was confirmed with anatomic and functional MRI and high-resolution EEG. His cortical visual impairment was severe, but he retained a remarkable ability to see fast-moving stimuli. Horizontal optokinetic nystagmus could be elicited from either eye. Resolution acuity was close to normal providing the patient was allowed to move his head and eyes. The direction of motion in random-dot patterns could be discriminated with perfect accuracy at speeds above 2 deg/s, and the patient reported that he could 'see' the motion at fast but not at slow speeds. This conscious residual vision for motion is known as Riddoch's phenomenon, but it has never been reported in the complete absence of the striate cortex. Functional neuroimaging revealed activation that was outside the motion-responsive regions of the extrastriate cortex. This case demonstrates remarkable plasticity in the human visual system and may have implications for understanding the functional organization of the motion pathways.

Adult↗

PubMed2002

Dose response to melatonin treatment for disordered sleep rhythm in a blind child.

We assessed the effectiveness and safety of melatonin in normalizing sleep in a 7-year-old blind child with a longstanding sleep/wake cycle disorder, using a double-masked, randomized treatment trial of placebo, a physiological dose (0.14 mg) and a supraphysiological dose (2.2 mg) of melatonin. Sleep onset and sleep offset were erratic and inappropriately early with placebo and low dose melatonin, but improved significantly on high dose melatonin. This report confirms that melatonin may be effective in treatment of disordered sleep rhythm in blind children, and illustrates a protocol that enables dose adjustment for optimal treatment response.

Clinical Trial↗

PubMed2002

Garlic and the strabismus surgeon.

Potential side-effects caused by complementary medicines are often not anticipated. A case is reported of bilateral retro-bulbar haemorrhages with elevated intraocular pressure during strabismus surgery that occurred as a result of odourless garlic tablet ingestion prescribed by a naturopath. A near-catastrophic event was averted with rapid recognition and medical treatment. This is believed to be the first such report of haemorrhaging in ophthalmic surgery induced by garlic. It is concluded that unregulated naturopathic prescribing is potentially dangerous; doctors need to ask specifically about naturopathic potions.

Complementary Therapies↗

PubMed2002

Bilateral congenital corneal keloids and anterior segment mesenchymal dysgenesis in a case of Rubinstein-Taybi syndrome.

PURPOSE: To report the unusual association of bilateral corneal keloids and anterior segment mesenchymal dysgenesis in a child with Rubinstein-Taybi syndrome. METHODS: Case report of a 2-year-old boy. RESULTS: Excision of the epicorneal mass in the right eye was followed by recurrence of the lesion. Multiple penetrating keratoplasties were unsuccessful in reconstructing the anterior segment because of recurrent corneal epithelial breakdown, suggesting limbal stem cell insufficiency. Histopathology and electron microscopy of the excised mass lesion showed features typical of a corneal keloid: thickened keratinized epithelium, absent Bowman's layer, and fibrovascular hyperplasia, with haphazard orientation of the collagen lamellae. Ultrasound biomicroscopy and intraoperative findings suggested a diagnosis of Peter anomaly, but genetic analysis did not show a PAX6 mutation. CONCLUSION: The findings in our patient add to the spectrum of ocular changes described in Rubinstein-Taybi syndrome and confirm earlier reports of poor ocular prognosis in corneal keloids and Rubinstein-Taybi syndrome.

Anterior Eye Segment↗

PubMedDate not supplied

The early treatment for ROP (ETROP) randomized trial: study results and nursing care adaptations.

The Early Treatment for Retinopathy of Prematurity (ETROP) study, funded by the National Eye Institute, has shown that early treatment of high-risk prethreshold retinopathy of prematurity (ROP) improves retinal and visual outcomes at 9 months corrected age. These favorable study results have yielded new guidelines for treatment of infants with ROP This paper reviews the study methodology and results and outlines the neonatal and ophthalmic nursing interventions influenced by this new treatment schedule. Four critical phases, screening/examination, treatment, evaluation, and follow-up, are identified, and key nursing objectives and tasks are discussed.

Aftercare↗