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Biomedical subjects

Alexander J Brucker

Publications and source records attributed to Alexander J Brucker.

14 recordsLinked to original sources
PubMed2005

Coats' disease diagnosed in adulthood.

PURPOSE: To investigate the manifestations and clinical course of Coats' disease diagnosed in adulthood and to describe the characteristics of patients who develop it. DESIGN: Retrospective observational case series. PARTICIPANTS: Thirteen eyes of 13 patients with Coats' disease diagnosed after age 35 years. METHODS: All patients examined in the authors' referral practices for Coats' disease diagnosed after the age of 35 years were identified. Patients with a history of radiation exposure, intraocular inflammation, retinal vascular occlusion, or Coats' response were excluded. A review of their historical, clinical, and fluorescein angiographic features and demographics was performed. RESULTS: There were 13 patients with a mean age at diagnosis of 50 years (range, 36-79) and a mean follow-up of 5.8 years (range, 0-17). These patients manifested many findings typical of Coats' disease, including the unilateral nature of the disease (13/13 patients), male predominance (12/13), vascular telangiectasis, lipid exudation, macular edema, and areas of capillary nonperfusion with adjacent webs of filigreelike capillaries. Disease was limited to < or =6 clock hours in 10 of 13 patients (76.9%), did not generally involve the retinal vasculature anterior to the equator, and showed limited potential to expand during the follow-up period. A localized hemorrhage was noted in 10 of 13 patients (76.9%), almost always near larger aneurysmal dilatations. Limited exudative detachment of the retina was seen in 4 eyes, 3 of which responded to localized laser photocoagulation. One patient had subretinal fluid seen on ocular coherence tomography that did not require treatment. On average, patients lost 2.1 lines of visual acuity during the follow-up period; 6 patients had a decline in vision, 2 patients had improved vision, and 3 patients had stable vision. No patient had end-stage findings of Coats' disease, such as iris neovascularization or total exudative detachment. CONCLUSIONS: Coats' disease can first be diagnosed in adulthood with retinal vascular abnormalities similar to those seen in younger patients. There are a number of important differences in disease manifestation in adults, including limited area of involvement, slower apparent progression of disease, and hemorrhage near larger vascular dilatations.

Adult↗
PubMed2004

Mutations in ABCA4 result in accumulation of lipofuscin before slowing of the retinoid cycle: a reappraisal of the human disease sequence.

Mutations in ABCA4, which encodes a photoreceptor specific ATP-binding cassette transporter (ABCR), cause autosomal recessive forms of human blindness due to retinal degeneration (RD) including Stargardt disease. The exact disease sequence leading to photoreceptor and vision loss in ABCA4-RD is not known. Extrapolation from murine and in vitro studies predicts that two of the earliest pathophysiological features resulting from disturbed ABCR function in man would be slowed kinetics of the retinoid cycle and accelerated deposition of lipofuscin in the retinal pigment epithelium (RPE). To determine the human pathogenetic sequence, we studied surrogate measures of retinoid cycle kinetics, lipofuscin accumulation, and rod and cone photoreceptor and RPE loss in ABCA4-RD patients with a wide spectrum of disease severities. There were different extents of photoreceptor/RPE loss and lipofuscin accumulation in different regions of the retina. Slowing of retinoid cycle kinetics was not present in all patients; when present, it was not homogeneous across the retina; and the extent of slowing correlated well with the degree of degeneration. The orderly relationship between these phenotypic features permitted the development of a model of disease sequence in ABCA4-RD. The model predicted lipofuscin accumulation as a key and early component of the disease expression in man, as in mice. In man, however, abnormal slowing of the rod and cone retinoid cycle occurs at later stages of the disease sequence. Knowledge of the human ABCA4 disease sequence will be critical for defining rates of progression, selecting appropriate patients and retinal locations for future therapy, and choosing appropriate treatment outcomes.

ATP-Binding Cassette Transporters↗
PubMed2004

Foveolar choroidal hemodynamics in proliferative diabetic retinopathy.

PURPOSE: We studied the choroidal circulation in patients with proliferative diabetic retinopathy (PDR) to assess whether choroidal hemodynamic abnormalities may exist in PDR. METHODS: Eighteen eyes of 18 patients with PDR and high-risk characteristics for visual loss were included in this study. Mean duration of diabetes was 20 +/- 9 years (mean +/- SD), hemoglobin A1c was 8.9 +/- 2.3%, and blood glucose at the time of blood flow measurement was 188 +/- 90 mg/dl. Choroidal circulatory parameters obtained in these patients were compared to those of 35 eyes of 35 age and blood pressure matched, healthy controls using a Wilcoxon rank sum test. Laser Doppler flowmetry (Oculix) was used to calculate relative choroidal blood velocity (Chvel), volume (Chvol), and flow (Chflow) in the center of the foveola. RESULTS: No significant differences in average age, mean blood pressure (BPm), or perfusion pressure (PP) were observed between diabetic patients and control subjects. In diabetic patients, Chvol was 0.29 +/- 0.08 (mean +/- 1 SD) arbitrary units (AU); this value was 15% lower than that of control subjects, 0.34 +/- 0.10 AU (p = 0.04). In contrast, average Chvel was not significantly different between subjects with PDR (0.39 +/- 0.07 AU) and control subjects (0.41 +/- 0.07 AU). The average Chflow in subjects with PDR (9.4 +/- 2.9 AU) was 27% lower than that of control subjects (12.8 +/- 4.2 AU; p = 0.003). No significant correlation was detected between the circulatory measurements and age, BPm, or PP. There was a statistically significant negative correlation between duration of diabetes and Chvel (R = -0.55; p = 0.03). CONCLUSIONS: Our results suggest that Chvol and Chflow are significantly reduced in patients with PDR.

Adult↗
PubMed2004

Intravitreal injection of vascular endothelial growth factor small interfering RNA inhibits growth and leakage in a nonhuman primate, laser-induced model of choroidal neovascularization.

PURPOSE: To determine the safety and efficacy of small interfering RNA (siRNA) directed against vascular endothelial growth factor (VEGF) in a nonhuman primate model of laser-induced choroidal neovascularization (CNV). METHODS: Each animal received laser rupture of Bruch's membrane to induce CNV in both eyes. Each animal was then randomized to receive 0.05 mL of either vehicle alone or VEGF siRNA at 70 microg, 150 microg, or 350 microg in both eyes by intravitreal injection. Eyes were monitored weekly by ophthalmic examination, color photography, and fluorescein angiography for 36 days after laser injury. Electroretinograms were measured at baseline and at 5 weeks after laser. CNV on fluorescein angiograms were measured for area and graded for clinically significant leakage in a standardized, randomized, and double-masked fashion on days 15, 22, 29, and 36 after laser. RESULTS: VEGF siRNA did not cause any change in electroretinographic, hemorrhage, inflammation, or clinical signs of toxicity. A single administration of VEGF siRNA significantly inhibited growth of CNV and attenuated angiographic leakage in a dose-dependent manner. CONCLUSION: Intravitreal injection of VEGF siRNA is capable of inhibiting the growth and vascular permeability of laser-induced CNV in a nonhuman primate in a dose-dependent manner. This study demonstrates preclinical proof of a principle that supports proceeding to clinical studies of VEGF siRNA in patients with exudative age-related macular degeneration.

Animals↗
PubMed2004

Evolving guidelines for intravitreous injections.

Intravitreous (i.v.t.) injection is increasingly being incorporated into the management of ocular diseases. While only fomivirsen sodium (Vitravene) is currently approved by the Food and Drug Administration as an i.v.t. injection, the number of approved i.v.t. injections indications is anticipated to grow on the basis of promising results from ongoing clinical studies. Despite the potential benefits that may be derived from intraocular injections of different agents, no guidelines have been published previously for i.v.t. injection. The purpose of this document is to identify specific strategies for the delivery of i.v.t. injection that may reduce risks and improve outcomes. Consensus was sought among a panel of investigators, surgeons experienced with this technique, and industry representatives. Objective evidence was sought for all guidelines, but consensus was accepted where evidence remains incomplete. In the absence of either evidence or consensus, the current manuscript identifies outstanding issues in need of further investigation. It is anticipated that more complete guidelines will evolve over time, potentially altering some of the guidelines included here, based on new applications of i.v.t. injection, additional clinical experience, and results of clinical trials.

Humans↗
PubMed2003

Foveal spot: a report of thirteen patients.

PURPOSE: To describe the natural history of a series of patients with a small foveal or juxtafoveal red lesion. METHODS: Retrospective chart review of 13 patients with a small foveal or juxtafoveal red spot. Long-term follow-up examination was obtained in seven patients. RESULTS: Thirteen patients with a mean age of 34.6 years are reported. Initial visual complaints ranged from no complaints to mild blurring and central distortion of vision. None of the patients had a history of sun gazing or known macular disease. Eleven of the 13 patients had best-corrected visual acuities in the involved eye that were better than 20/30. The lesions were bilateral in five patients and unilateral in eight. When performed, optical coherence tomography and fluorescein angiography were unremarkable. Follow-up was obtained in seven patients (mean, 58 months), and visual acuity remained stable in all affected eyes. In all patients, the lesions remained stable without expansion or alteration of the foveal appearance over the course of follow-up. CONCLUSIONS: This report identifies a foveal or juxtafoveal, irregular, apparently intraretinal, red lesion of unclear cause. Long-term follow-up of these patients has demonstrated stable visual acuity and lesion appearance.

Adolescent↗
PubMed2002

The detection of a relative afferent pupillary defect.

PURPOSE: To describe a simple technique that detects a subtle relative afferent pupillary defect. DESIGN: Observational report. METHODS: With the patient seated at a slit lamp and the slit illumination turned off, a transilluminator light is swung back and forth between the eyes. The examiner observes the direct pupil light response and the consensual light response under slit-lamp magnification. CONCLUSION: Using slit-lamp magnification, the examiner may observe small amplitudes of pupillary movement in the evaluation of a relative afferent pupillary defect.

Diagnostic Techniques, Ophthalmological↗
PubMedDate not supplied

Neovascular age-related macular degeneration: roundtable.

Several recent developments may provide an opportunity to improve outcome in individuals who develop neovascular age-related maculopathy (age-related macular degeneration [ARMD]). Concurrent with progress in isolating clinically relevant subtypes of neovascular ARMD, several therapies have been introduced that show promise for halting progression of this disorder. However, data from controlled clinical trials to test the relative efficacy of different management strategies across these subtypes of disease presentation remain limited. In addition, strategies to control ARMD may evolve quickly as more is learned about how specific molecular events, such as cell-mediated inflammation and angiogenesis, contribute to disease expression. A roundtable of investigators was convened to discuss and summarize recent progress in the treatment of ARMD. Case studies were then presented to provide an opportunity for experts to reveal their specific thought processes in the approach to neovascular ARMD based on their own interpretation of current clinical data and empirical experience.

Adult↗