Abstract:
PURPOSE:Clonidine and brimonidine, two alpha-2 agonists, have been shown to reduce intraocular pressure (IOP) in patients with glaucoma. Little is known, however, about the exact role of alpha receptors in the control of ocular blood flow in the posterior pole of the eye. Hence, the study was conducted to investigate the effects of topical clonidine versus topical brimonidine on choroidal blood flow and intraocular pressure during squatting. METHODS:This was a randomized, double-masked, controlled, two-way crossover study. Twelve healthy male nonsmoking volunteers, aged between 19 and 35 years were included in the study. Two drops of clonidine or brimonidine were administered in the subjects' study eyes. Continuous measurement using the compact laser Doppler flowmeter was performed during a 6-minute squatting period, to assess choroidal blood flow regulation during an increase in ocular perfusion pressure. RESULTS:Both substances induced a pronounced but comparable (P = 0.8) decrease in IOP. Squatting increased mean arterial pressure (MAP) and ocular perfusion pressure (P < 0.01). This increase was comparable between the clonidine and the brimonidine study day (P = 0.88). Squatting induced an increase in choroidal blood flow that was less pronounced than the increase in ocular perfusion pressure. Compared with baseline the alpha-2 agonists decreased choroidal blood flow during squatting (P = 0.0026) to a comparable degree (P = 0.86). Vascular resistance increased at baseline and during squatting after administration of the alpha-2 agonists (P < 0.01) in both groups to a comparable degree (P = 0.56). CONCLUSIONS:Topical alpha-2 agonists may induce changes in choroidal blood flow, even after a single administration. Long-term studies are needed to study potential effects of brimonidine and clonidine in the clinical setting.
journal_name
Invest Ophthalmol Vis Scijournal_title
Investigative ophthalmology & visual scienceauthors
Weigert G,Resch H,Garhofer G,Fuchsjäger-Mayrl G,Schmetterer Ldoi
10.1167/iovs.07-0178subject
Has Abstractpub_date
2007-09-01 00:00:00pages
4220-5issue
9eissn
0146-0404issn
1552-5783pii
48/9/4220journal_volume
48pub_type
杂志文章,随机对照试验abstract::The relationship of the ocular pressure to the anterior ciliary arterial pressure was studied by measuring the pressure of the anterior ciliary artery using a modified pressure chamber. Of the 40 subjects, 9 were normal, 16 were ocular hypertensive patients, and 15 were primary, open-angle, glaucoma patients. A signif...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1984-08-01 00:00:00
abstract:PURPOSE:The aim of this study was to show the usefulness of three methods for measuring IOP: Goldmann applanation tonometry, rebound tonometry, and Ultra-High-Speed Scheimpflug technology. METHODS:The examined group consisted of 96 patients (192 eyes), including 63 women and 33 men with a mean age of 59.3 ± 19.9 years...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.13-13172
更新日期:2014-02-04 00:00:00
abstract:PURPOSE:The authors investigated how individual differences in macular pigment (MP) density are related to loss of visual sensitivity with age. METHODS:Macular pigment and visual sensitivity of 27 healthy older subjects (aged 60-84 years) were compared with data from 10 younger subjects (aged 24-36 years). Macular pig...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00
abstract:PURPOSE:To study in an infant rat model of retinopathy of prematurity, the rod photoreceptors, which are known to have attenuated photoresponses. METHODS:Rhodopsin was extracted from whole retinas, the thickness of the rod outer segment (ROS) layer was measured, large phagosomes were counted, and the ROS ultrastructur...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract:PURPOSE:Angiotensin II (AII) has been shown to play a role in many vascular diseases. In the study described, the effect of AII on vascular endothelial growth factor (VEGF) expression and related intracellular signaling mechanism was investigated in bovine retinal microcapillary pericytes. METHODS:Cultured bovine reti...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:2000-04-01 00:00:00
abstract:PURPOSE:To investigate the biometric characteristics of eyes with idiopathic central serous chorioretinopathy (CSC). METHODS:Medical records of 52 consecutive patients with unilateral CSC were reviewed. Central serous chorioretinopathy was diagnosed using spectral-domain optical coherence tomography (SD-OCT) and fluor...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.13-13183
更新日期:2014-03-13 00:00:00
abstract::The elastic fiber consists of several components: a central core of alpha-elastin and a microfibrillar sheath containing three components: fibrillin, microfibril-associated glycoprotein, and a 35-kD protein with amine oxidase activity. Elastin is a major component of the elastic fibers of the extracellular matrix (ECM...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract:PURPOSE:Previous sequence analyses of hemidesmosomal BP 180/collagen XVII cDNA from human skin and of a similar chicken corneal cDNA showed some similarities, but major differences as well. The authors examined whether, in one species, the same mRNA is present in cornea and skin. They also studied the developmental exp...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1997-01-01 00:00:00
abstract:Purpose:To assess clinical characteristics, foveal structure, mutation spectrum, and prevalence rate of Åland eye disease (AED)/incomplete congenital stationary night blindness (iCSNB). Methods:A retrospective survey included individuals diagnosed with AED at a national low-vision center from 1980 to 2014. A subset of...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.16-19445
更新日期:2016-12-01 00:00:00
abstract:PURPOSE:To evaluate the histologic effects and clinical outcomes of high-intensity focused ultrasound (HIFU) delivered by miniaturized annular transducers for ciliary body coagulation in an animal study. METHODS:Eighteen eyes of 18 rabbits were insonified with a ring comprising a six-sector transducer, to produce a 12...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.09-5135
更新日期:2010-10-01 00:00:00
abstract::The laser Doppler technique was used to measure alterations in retinal blood flow in human subjects under dark-adapted conditions compared to light-adapted conditions. Retinal blood flow increased 40 to 70% after the transition from light to dark. We show quantitatively that the measured increases in retinal blood flo...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
abstract::Congenic mice of the MRL/Mp strain spontaneously develop an autoimmune connective tissue disease that shares immunologic and histopathologic features with the human disorders systemic lupus erythematosus, rheumatoid arthritis, and systemic vasculitis. The autoimmune disorder in these mice is markedly accelerated by th...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1985-09-01 00:00:00
abstract:PURPOSE:To determine whether ciliary neurotrophic factor (CNTF) or brain-derived neurotrophic factor (BDNF) treatment leads to long-term photoreceptor survival in hereditary retinal degeneration. METHODS:An autosomal dominant feline model of rod-cone dystrophy was used throughout the study with two normal animals. In ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1999-05-01 00:00:00
abstract:PURPOSE:Regulatory CD4+ T cells (T regs) arise in the spleens of mice with anterior chamber-associated immune deviation (ACAID), an eye-derived tolerance evoked by injection of antigen into the ocular anterior chamber (AC). The current study was conducted to investigate the possibility that these T regs express CD25 an...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.05-0110
更新日期:2006-03-01 00:00:00
abstract:PURPOSE:To determine if lens epithelial lines can be established from cryopreserved whole rabbit lenses and from cryopreserved capsule-epithelial preparations (CEPs). METHODS:Lenses or freshly isolated CEPs were cryopreserved and subsequently thawed. Thawed whole lenses were cultured for 48 hours in growth medium and ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1995-02-01 00:00:00
abstract:PURPOSE:To investigate functional interactions between the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and the nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent antioxidant system in cultured human retinal pigment epithelium (RPE) cells. METHODS:Cultured ARPE-19 cells were treated with different concen...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.07-1099
更新日期:2008-04-01 00:00:00
abstract::N-formimidoyl thienamycin (MK-787) is a new beta-lactam with potent activity against both aerobic and anaerobic gram-positive and gram-negative bacteria. Its spectrum and activity suggest it may be useful in treatment of complicated intraocular infections. Its ocular penetration was studied in New Zealand white rabbit...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1983-08-01 00:00:00
abstract:PURPOSE:To examine the temporal summation of a Goldmann III-sized stimulus under the conditions of standard automated perimetry in healthy participants of varying age. METHODS:Twenty-seven healthy individuals of varying age (24-80 years) were tested. Achromatic contrast thresholds were measured for seven 0.48° diamete...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.15-16920
更新日期:2015-10-01 00:00:00
abstract:PURPOSE:To reconstruct the role played by vascular endothelium in the elevation of circulating von Willebrand factor (vWf) in diabetic patients with microangiopathy and, specifically, to determine whether storage and synthesis of vWf is altered in diabetic retinal vessels. METHODS:Trypsin digests were prepared from re...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1994-02-01 00:00:00
abstract:PURPOSE:A great deal of information about functionally significant domains of a protein may be obtained by comparison of primary sequences of gene homologues over a broad phylogenetic base. This study was designed to identify evolutionarily conserved domains of the photoreceptor disc membrane protein peripherin/rds by ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.02-1152
更新日期:2003-06-01 00:00:00
abstract:PURPOSE:Protein kinases C (PKCs) are key cell-signaling mediators in retinal physiology and pathophysiology. The cellular localization of PKC isoforms is important in defining their activity and specificity; the present study investigated the modulatory potential of the proinflammatory mediator platelet-activating fact...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.05-0290
更新日期:2006-01-01 00:00:00
abstract:PURPOSE:To investigate the molecular basis of hereditary lattice corneal dystrophy (LCD) type IIIA associated with corneal amyloid deposits afflicting several members of a four-generation family. METHODS:Histologic, immunohistochemical and biochemical studies were performed on corneal tissue samples obtained after per...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.04-1319
更新日期:2005-04-01 00:00:00
abstract:PURPOSE:Retinal ganglion cell (RGC) degeneration is an important cause of visual impairment and can be modeled by optic nerve transection, which causes the death of 90% of RGCs within 14 days postaxotomy. We performed a proteomic study to identify and quantify proteins in the rat retina after optic nerve transection. O...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.11-8350
更新日期:2012-06-26 00:00:00
abstract:PURPOSE:Vaccinia virus keratitis leading to blindness is a severe complication of smallpox vaccination. The clinical manifestations of vaccinia virus keratitis are similar to those of herpes simplex virus keratitis, a well-studied immunopathologic disease. Vaccinia virus keratitis is likely to involve an immunopatholog...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.09-5107
更新日期:2010-09-01 00:00:00
abstract::Upper eyelid movements were recorded in nine human subjects by mounting a miniature coil of wire directly on the eyelid and subjecting the search coil to a vertically directed alternating magnetic field. The metrics of blinks and lid movements accompanying saccades were described by "main sequence" relationships, link...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
abstract::Experiments were performed with a model of focal, thermal-induced ulceration to test the clinical impression that vascularization prevents ulceration of the corneal stroma. Slow-release polymers containing a vasoproliferase agent (tumor angiogenesis factor) were placed in corneal pockets 2 mm central to the limbus of ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1980-04-01 00:00:00
abstract:PURPOSE:Photodynamic therapy (PDT) and the administration of compounds acting against vascular endothelial growth factor (anti-VEGF) are approved for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). Experimental evidence that the combined use of both treatment opt...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.06-1224
更新日期:2007-04-01 00:00:00
abstract:PURPOSE:We showed previously that single nucleotide polymorphism (SNP) rs662702 in PAX6 may be located in a microRNA-328 binding site that causes susceptibility to high myopia. Our study was done to elucidate the role of PAX6 and its relationship with microRNA-328 in myopia. METHODS:A luciferase assay was used to conf...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.11-9272
更新日期:2012-05-31 00:00:00
abstract:PURPOSE:The purpose of this study was to evaluate the performance of optical coherence tomography angiography (OCTA) in visualizing laser-induced choroidal neovascularization (CNV) in the rodent retina. METHODS:Choroidal neovascularization was induced via laser photocoagulation in 2 male Brown Norway rats and 2 male C...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.15-18946
更新日期:2016-07-01 00:00:00
abstract:PURPOSE:To determine global mRNA expression levels in corneal and conjunctival epithelia and identify transcripts that exhibit preferential tissue expression. METHODS:cDNA samples derived from human conjunctival and corneal epithelia were hybridized in three independent experiments to a commercial oligonucleotide arra...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.06-0998
更新日期:2007-05-01 00:00:00