Pressure Elevation In Patients Research Articles

Analysis of Indicators for Assessing the Risk of Progression from PACS to APAC and the Degree of Intraocular Pressure Elevation in APAC Using AS-OCT.

The aim of this study is to quantify anterior chamber parameters to provide potential risk indicators for evaluating the progression of primary angle-closure suspect (PACS) eyes to acute primary angle closure (APAC) and the degree of intraocular pressure elevation in patients with APAC utilizing anterior segment optical coherence tomography (AS-OCT). Tomey CASIA2 AS-OCT was used to quantitatively measure various anterior chamber parameters, including anterior chamber depth (ACD), anterior chamber volume (ACV), lens thickness (LT), lens vault (LV), iris-trabecular contact index (ITC), iris thickness (IT), iris volume (IV), iris curvature (IC), iris area (IA), and iris thickness (IT), in APAC eyes (30 eyes) and contralateral PACS eyes (30 eyes) of 30 patients. The differences in these parameters between the two groups and their relationship with intraocular pressure were analyzed. Compared to the PACS group, the APAC group exhibited significantly smaller IA and IC, and significantly larger pupil diameter (PD) and ITC (P < 0.05). There were no statistically significant differences in ACV, ACD, ACW, ACA, LV, IV, and IT750/2000 between the two groups. In APAC eyes, multivariable linear regression analysis showed a significant negative correlation between intraocular pressure and IV (β = -1.85; 95% confidence interval: -2.77 to -0.93; P=0.001), while no correlation was found in PACS eyes. In all 60 eyes, LT showed a negative correlation with ACV, ACD, ACA, and nasal IT750, and a positive correlation with LV and nasal IC. AS-OCT has multiple advantages in evaluating various anterior chamber parameters in patients with glaucoma. IA may serve as a predictive indicator of the progression of eyes from PAC or APAC. A significant negative correlation was found between intraocular pressure and IV during APAC attacks. LT can be considered a predictive factor for the occurrence of primary angle-closure disease.

Optical Coherence Tomography Angiography Findings after Acute Intraocular Pressure Elevation in Patients with Diabetes Mellitus versus Healthy Subjects.

Purpose To assess the changes in optic nerve head and macular microvascular networks after acute intraocular pressure (IOP) rise in healthy eyes versus the eyes of diabetic patients.MethodsIn this prospective, interventional, comparative study, 24 eyes of 24 adults including 12 eyes of healthy nondiabetic subjects and 12 eyes with mild or moderate non-proliferative diabetic retinopathy (NPDR) were enrolled. IOP elevation was induced by a suction cup attached to the conjunctiva. IOP and optical coherence tomography angiographic (OCTA) images of the optic disc and macula were obtained before and immediately after the IOP rise.ResultsBaseline and post-suction IOPs were not significantly different between the two groups (all P 0.05). The mean IOP elevation was 13.93 3.41 mmHg among all eyes and was statistically significant as compared to the baseline in both groups (both P 0.05). After IOP elevation, healthy eyes demonstrated a reduction in the vessel density in the whole image deep and superficial capillary plexuses and parafoveal deep capillary plexus (DCP) (all P 0.05). In diabetic retinopathy, foveal vessel density at DCP decreased significantly following IOP rise (P = 0.003). In both groups, inside disc vessel density decreased significantly after IOP rise (both P 0.05), however, no significant change was observed in peripapillary vessel density (both P 0.05).ConclusionAcute rise of IOP may induce different levels of microvascular changes in healthy and diabetic eyes. Optic disc microvasculature originating from the posterior ciliary artery may be more susceptible to IOP elevation than that of retinal microvasculature.

Role of miR-21-5p/FilGAP axis in estradiol alleviating the progression of monocrotaline-induced pulmonary hypertension.

BackgroundAberrant expression of microRNAs (miRNAs) has been associated with the pathogenesis of pulmonary hypertension (PH). It is, however, not clear whether miRNAs are involved in estrogen rescue of PH.MethodsFresh plasma samples were prepared from 12 idiopathic pulmonary arterial hypertension (IPAH) patients and 12 healthy controls undergoing right heart catheterization in Shanghai Pulmonary Hospital. From each sample, 5 μg of total RNA was tagged and hybridized on microRNA microarray chips. Monocrotaline‐induced PH (MCT‐PH) male rats were treated with 17β‐estradiol (E2) or vehicle. Subgroups were cotreated with estrogen receptor (ER) antagonist or with antagonist of miRNA.ResultsMany circulating miRNAs, including miR‐21‐5p and miR‐574‐5p, were markedly expressed in patients and of interest in predicting mean pulmonary arterial pressure elevation in patients. The expression of miR‐21‐5p in the lungs was significantly upregulated in MCT‐PH rats compared with the controls. However, miR‐574‐5p showed no difference in the lungs of MCT‐PH rats and controls. miR‐21‐5p was selected for further analysis in rats as E2 strongly regulated it. E2 decreased miR‐21‐5p expression in the lungs of MCT‐PH rats by ERβ. E2 reversed miR‐21‐5p target gene FilGAP downregulation in the lungs of MCT‐PH rats. The abnormal expression of RhoA, ROCK2, Rac1 and c‐Jun in the lungs of MCT‐PH rats was inhibited by E2 and miR‐21‐5p antagonist.ConclusionsmiR‐21‐5p level was remarkably associated with PH severity in patients. Moreover, the miR‐21‐5p/FilGAP signaling pathway modulated the protective effect of E2 on MCT‐PH through ERβ.

Intraocular Pressure in Eyes with Intraocular Lens Dislocation and Pseudoexfoliation Syndrome.

To investigate intraocular pressure in eyes with intraocular lens subluxation and pseudoexfoliation syndrome. In this retrospective study conducted at one eye centre (tazz) in Zurich, Switzerland, we reviewed 85 eyes with intraocular lens subluxation and pseudoexfoliation syndrome. Intraocular lens exchange was carried out by two surgeons between 03/2016 and 12/2019 (45 months). Information on baseline characteristics and diagnosis of glaucoma was recorded. Intraocular pressure and best-corrected visual acuity were analysed preoperatively and at five time points up to 12months after lens exchange. Data on antiglaucomatous medication was collected before surgery and at two different time points after surgery. Postoperative pressure lowering procedures and complications were further analysed. This study includes 85 pseudoexfoliation eyes with intraocular lens subluxation. The mean interval between cataract surgery and lens exchange was 8.9 ± 5.2 years. Intraocular pressure elevation in the event of intraocular lens subluxation was found in 54% (46/85) of eyes. Mean intraocular pressure decreased from 22.9 ± 9.4 mmHg preoperatively to 15.2 ± 3.4 mmHg at follow-up 12 months after lens exchange (p < 0.001). Postoperative topical antiglaucomatous drug requirements were comparable to preoperative levels (p = 0.520). Less systemic acetazolamide was required 12 months postoperatively (p = 0.018). A pressure lowering procedure was required in seven (8%) eyes in the postoperative period due to persistence of high intraocular pressure. Intermittent increase or persistence of high intraocular pressure occurred in 13 (15%) eyes. This study emphasises the connection between acute pressure elevation and intraocular lens subluxation in patients with pseudoexfoliation syndrome. Intraocular pressure decreases after lens exchange and decrease sustains for a postoperative period of 12 months. Postoperative pressure lowering procedures were not required in the majority of eyes. We therefore conclude that intraocular lens exchange is efficient in the management of lens subluxation and pressure elevation in patients with pseudoexfoliation syndrome.

RENAL SODIUM HANDLING ABNORMALITY IN OBSTRUCTIVE SLEEP APNEA-RELATED HYPERTENSION

Objective: Obstructive sleep apnea (OSA) has been much focused as one of underlying factors of resistant hypertension. A substantial number of mechanisms (sympathetic nerve activation, oxidative stress, renin-angiotensin-aldosterone system, systemic inflammation and fluid retention) contributed to OSA-related hypertension, and these factors can lead to resistant hypertension. However, renal sodium handling abnormality in OSA patients with hypertension has not been fully clarified. Design and method: We evaluated the urine sodium excretion before and after continuous positive airway pressure (CPAP) therapy in OSA. 24-h urinary sodium excretion was estimated at baseline and after 6 months of CPAP using the Kawasaki formula, and fractional urinary sodium excretion (FENa) was also calculated in 23 OSA patients with hypertension. Results: In patients with severe OSA, 24 h Na excretion had no significant correlation with AHI, abdominal circumference and plasma aldosterone. After CPAP therapy, systolic blood pressure significantly decreased (P &lt; 0.05), and estimated sodium excretion significantly increased compared to baseline (P &lt; 0.05). The increase in Na excretion was significantly associated with BP reduction by CPAP therapy. Conclusions: These results suggested that urine sodium excretion abnormality contribute to the blood pressure elevation in patients with OSA. Therefore, urine sodium excretion may be a key mechanism in managing OSA-related hypertension.

Association of AGTR1 (rs5186), VDR (rs2228570) genes polymorphism with blood pressure elevation in patients with essential arterial hypertension.

Essential arterial hypertension (EAH) is a polygenic disease due to environmental, genetic, and epigenomic factors. The study aimed to establish the association of single nucleotide polymorphism (SNP) of AGTR1 (rs5186) and VDR (rs2228570) genes with the blood pressure (BP) elevation in EAH patients. 100 EAH subjects with hypertensive-mediated organ damaging (2nd stage), moderate, high, or very high cardiovascular risk were recruited into the case-control study. There were 70.83% females and 29.17% males, mean age 57.86±7.81 y.o. The control group included 60 healthy individuals of relevant age and gender distribution. Estimation of AGTR1 (rs5186) and VDR (rs2228570) gene polymorphism was performed by Real-Time Polymerase Chain Reaction. In EAH patients, the AGTR1 gene (rs5186) mutation occurs with a frequency of 2.78% in the absence of such among healthy individuals. The VDR (rs2228570) gene mutation occurs with a frequency of 23% cases. The C-allele carriers’ (AGTR1 gene) numbers with 2nd and 3rd BP values degree dominate over AA-genotype patients by 25.32% (χ2=4.52; p=0.033). VDR gene (rs2228570) polymorphic variants do not link to BP elevation values. Thus, the C-allele of the AGTR1 gene (rs5186) is associated with BP elevation in hypertensive patients. BP values do not depend on VDR gene (rs2228570) polymorphic variants.

Blood pressure response to detrusor pressure elevation in patients with a reflex urinary bladder after a cervical or high thoracic spinal cord injury

In 12 patients with a reflex urinary bladder after a cervical or high thoracic spinal cord injury, blood pressure was measured every 30 s during cystometry. Four consecutive cystometries were performed by means of suprapubical catheters and 50 ml/min filling rate. The aim was to improve the methodological basis for cystometrical studies of paroxysmal hypertension and its treatment. In each cystometry there was an elevation of the systolic (20-60 mmHg) and the diastolic (15-55 mmHg) blood pressure. The maximum blood pressure always occurred during the emptying phase and always in close relation to the peak of the detrusor pressure. The amplitude of the blood pressure response varied intraindividually, but did not change in any particular direction during the series of cystometries. Thus, a cystometrical method which stimulates the detrusor in a physiological way is sufficient to give the typical uninhibited blood pressure reaction in most patients with a reflex bladder and a spinal reflex vasomotor function after a high level spinal cord injury. The blood pressure reaction obtained with this method is probably representative for the daily reaction during physiological reflex emptying of the bladder. To describe the maximum blood pressure reaction, it has to be measured during a well defined emptying phase and close to the occurrence of the maximum detrusor pressure. Since repetition of cystometry did not change the blood pressure response, this cystometrical method is useful for evaluation of pharmacological intervention.

Effect of different lens status on intraocular pressure elevation in patients treated with anti-vascular endothelial growth factor injections

To assess the effect of lens status on sustained intraocular pressure (IOP) elevation in patients treated intravitreally with anti-vascular endothelial growth factor (VEGF) agents. Data were retrospectively collected for all patients treated with intravitreal injections of anti-VEGF medication at a tertiary medical center in July 2015. Findings were analyzed by lens status during 6 months' follow-up. The main outcome measure was a sustained increase in IOP (≥21 mm Hg or change of ≥6 mm Hg from baseline on ≥2 consecutive visits, or addition of a new IOP-lowering medication during follow-up). A total of 119 eyes of 100 patients met the study criteria: 40 phakic, 40 pseudophakic, and 39 pseudophakic after Nd:YAG capsulotomy. The rate of sustained IOP elevation was significantly higher in the post-capsulotomy group (23.1%) than in the phakic/pseudophakic groups (8.1%; P=0.032), with no statistically significant differences among the 3 groups in mean number of injections, either total (P=0.82) or by type of anti-VEGF mediation (bevacizumab: P=0.19; ranibizumab: P=0.13), or mean follow-up time (P=0.70). Nd:YAG capsulotomy appears to be a risk factor for sustained IOP elevation in patients receiving intravitreal anti-VEGF injections. This finding has important implications given the growing use of anti-VEGF treatment and the irreversible effects of elevated IOP.

Predictive Factors of Intracranial Pressure Elevation in Patients with Severe Acute Subdural Hematoma

Elevated intracranial pressure(ICP)can cause secondary brain injury after severe traumatic brain injury(TBI), and ICP is the key factor that determines the outcome. Therefore, prediction of elevation of ICP during the course of the injury would allow for more effective care of patients with severe TBI. In this study, we investigated predictive factors for elevation of ICP in patients with severe acute subdural hematoma(ASDH). Twenty patients with severe isolated ASDH were admitted to our hospital between January 2009 and April 2016. The patients were divided into two groups with a maximum ICP of ≥20mmHg(elevated ICP group)and <20mmHg(normal ICP group). Age, mechanism of injury, Glasgow Coma Scale score on admission, initial head computed tomography findings, vital signs, serological and blood gas examinations, initial ICP, and clinical outcome were evaluated. The elevated ICP group had significantly higher initial ICP(5.0±3.1 vs. 30±22.4mmHg, p<0.01), arterial oxygen pressure(151.2±68.3 vs. 314.2±197.1mmHg, p<0.05), and activated partial thromboplastin time(APTT;28.17±3.1 vs. 35.96±8.0, p<0.05)at admission, and significantly lower fibrinogen level(273.3±65.1 vs. 188.1±82.4mg/dL, p<0.05)and favorable outcome rate(p<0.01). Our results show that high initial ICP, APTT, and arterial oxygen and low fibrinogen levels are associated with ICP elevation in patients with severe ASDH. These factors might be useful for the indication of therapeutic methods such as decompressive craniectomy.

Development and Testing of a Mobile Phone App for Risk Estimation of Gas Volume Expansion and Intraocular Pressure Elevation in Patients With Intravitreous Gas or Air Tamponade: Interobserver Assessment Study

BackgroundPars plana vitrectomy (PPV) with intravitreous tamponade of gas or air has been widely used for a series of vitreoretinal diseases. It is estimated that 100,000 patients per year undergo PPV globally, and half of them were subsequently tamponaded with gas or air. According to Boyle’s law (P1V1=P2V2), patients with an intravitreous remnant of gas or air will be under high risk of intraocular pressure (IOP) elevation and subsequent vision loss owing to the expanded intravitreous gas or air when traveling post operation to a place with a significantly higher altitude. We always explain to patients why postoperative travel is potentially risky. Emergency cases of elevated IOP caused by postoperative traveling would sometimes come to surgeons. However, there have been few disease education or reference tools for both the surgeons and patients to have better communication.ObjectiveThe aim of this study was to introduce and evaluate a mobile phone app developed by surgeons (the authors) for preliminary risk estimation of volume expansion and IOP elevation in patients with intravitreous gas or air when traveling to a place of higher altitude.MethodsThe app was developed on the iOS and Android operating systems. Boyle’s law (P1V1=P2V2) was the theoretical basis of the app. Intravitreous gas or air volume and altitude values were independent factors to deduce the risk report. Consecutive patients underwent vitrectomy, and those with an intravitreous remnant of gas or air were recruited. The surgeons judged the vertical height of the fluid/gas interface through the dilated pupil; the patients were instructed to judge it according to their visual field when looking straight ahead and line it out on a chart included in the app. Finally, all the patients were required to fill a Likert scale–based questionnaire with 2 main items to evaluate the participants’ user experience and attitudes toward the app.ResultsA total of 50 patients were included (30 males and 20 females). All patients could independently operate the app to complete the test. The median heights of the fluid/gas interface independently judged by the surgeon and patients were 40% (range: 10%-75%) and 41% (range: 9%-78%), respectively (P=.63). The median altitude of the participants’ destinations was 150.0 m (range: 0-3490 m). The Bland-Altman analysis revealed a good agreement between the surgeons’ and patients’ judgments (bias of −0.3%), with 95% limits of agreement of −5.8% to 5.3%. Overall, the Likert scale revealed a positive attitude from the patients toward the app.ConclusionsThe app is reliable for patients to have preliminary risk estimation of intravitreous gas or air volume expansion and IOP elevation if travel to a place of higher altitude is planned. The surgeons could also use it as a platform for better disease communication.

Management of Blood Pressure After Acute Ischemic Stroke.

The present manuscript examines the significance of blood pressure elevation in patients with acute ischemic stroke, the physiologic principles worthy of consideration during its treatment, and the recent empirical evidence that should guide management protocols. It also provides a sound and practical approach to treatment along the time continuum, with particular relevance to reperfusion strategies. The existing evidence shows that both insufficient and excessive blood pressures are detrimental to the outcome of patients with acute ischemic stroke. This "U-shaped" relation, however, relates to measurements at the time of presentation, and clinical studies lack detail and specificity relative to differential measurements along the time continuum, particularly prior to and following reperfusion. Extrapolating from recent series, it is possible to construct treatment protocols balanced for effectiveness and safety. The management of blood pressure after acute ischemic stroke is an important, complex, and challenging aspect of care, requiring a thorough understanding of cerebrovascular physiology. Along the time continuum, the therapeutic priorities start with the preservation of penumbral tissue prior to reperfusion and then follow with the limitation of the damaging effects of excessive blood pressure readings after reperfusion, optimizing the chances of improved outcomes.

Клиническое значение повышения внутрибрюшного давления у пациентов с тяжелым острым панкреатитом

Клиническое значение повышения внутрибрюшного давления у пациентов с тяжелым острым панкреатитом

Pre-Existing Antihypertensive Treatment Predicts Early Increase in Blood Pressure during Bevacizumab Therapy: The Prospective AVALUE Cohort Study

Background: Antiangiogenic therapy is routinely used in a variety of cancer entities. Hypertension is the most common side effect of all currently available antiangiogenic treatments. Patients and Methods: In this prospective observational clinical trial, we investigated risk factors for blood pressure elevation in patients exposed to an antiangiogenic agent and explored the correlation between hypertension and the duration of antiangiogenic treatment. Results: In 169 patients, pre-existing antihypertensive medication was the most prominent risk factor associated with increased blood pressure during therapy. Between visits 1 and 3, the median systolic blood pressure increased by 10.85 mmHg in patients with pre-existing hypertension receiving antihypertensive medication while it increased by only 2.69 mmHg in patients without hypertension. The median increase in diastolic pressure was 7.28 versus 0.11 mmHg in patients with versus without pre-existing hypertension. Increases in blood pressure occurred early (within 6 weeks of starting therapy). In spite of this significant increase in the blood pressure, no major bleeding events or other related complications were observed during antiangiogenic therapy. Conclusions: Pre-existing hypertension and treatment with antihypertensive medication correlated with a more pronounced increase in blood pressure. Thus, intensified antihypertensive therapy might be warranted early during bevacizumab therapy in patients already receiving antihypertensive treatment.

Blood pressure elevation in patients assisted in an emergency unit: cross-sectional study

Aims: To characterize hypertensive patients seen in an emergency unit for high blood pressure and to identify factors associated with the occurrence of moderate or severe hypertension. Method: This is a descriptive cross-sectional study conducted with 80 individuals. Data were collected in November 2013 by means of interviews with the application of a semi-structured questionnaire. Results: The following results were associated with moderate or severe hypertension: failure to attend the hypertensive group activities, alcohol consumption, lack of leisure activities and excessive salt consumption. Discussion: When nurses are able to recognize the factors that can influence uncontrolled blood pressure, they can more effectively stimulate the systematic outpatient care for hypertensive patients and the change in these patients’ lifestyle. Conclusion: Life habits associated with moderate or severe hypertension are modifiable according to the implementation of health education for professionals and self-care understanding by the users considered hypertensive.

Hemodynamic and pathophysiological characteristics of intradialytic blood pressure elevation in patients with end-stage renal disease

An increase in systolic blood pressure (SBP) after hemodialysis (intradialytic-HTN) is associated with adverse outcomes in patients on regular hemodialysis. However, the hemodynamic and Doppler echocardiographic characteristics of intradialytic-HTN and its impact on clinical outcomes are unclear. A retrospective analysis of 84 patients (45 men, 70±9 years) stratified into three groups on the basis of SBP response from pre- to post-hemodialysis: GHTN (intradialytic-HTN, SBP increase 10 mm Hg), GDROP<15 mm Hg (SBP drop <15 mm Hg), and GDROP15 mm Hg (SBP drop 15 mm Hg). Hemodynamic and echocardiographic assessments were performed pre- and post-hemodialysis, and patients were followed for 41±17 months. GHTN had higher blood glucose and lower baseline SBP, serum potassium and total cholesterol. Cardiothoracic ratio was smaller, and peak early diastolic mitral annular velocity (E') was lower in GHTN. During hemodialysis, SBP and diastolic blood pressure increased only in GHTN. After hemodialysis, left ventricular (LV) filling pressure (E/E' ratio) decreased only in GDROP15 mm Hg, resulting in a higher E/E' ratio in GHTN than GDROP15 mm Hg. Multivariate logistic regression analysis revealed a positive correlation between blood glucose and intradialytic-HTN, whereas cardiothoracic ratio, pre-hemodialysis SBP and the change in E/E' ratio with hemodialysis were negatively related to intradialytic-HTN. During follow-up, GHTN had more cardiovascular deaths than GDROP15 mm Hg (P=0.03). Multivariate Cox regression analysis showed that lower serum potassium and previous coronary artery disease, but not intradialytic-HTN, were associated with cardiovascular deaths. A higher LV afterload and elevated filling pressures after hemodialysis, indicative of increased cardiovascular stiffening and impaired diastolic filling, may contribute in part to an increased cardiovascular burden in patients with intradialytic-HTN.

Hypoglycemia-Induced Blood Pressure Elevation in Patients With Diabetes

Hypoglycemia-Induced Blood Pressure Elevation in Patients With Diabetes

Frequency Of Glaucoma In Children With Vernal Conjunctivitis Using Steroids

OBJECTIVE: To determine the frequency of glaucoma in children with vernal conjunctivitis using topical steroids, referred to a tertiary eye care centre. DESIGN: Descriptive case series. SETTING: This study was carried out at department of Ophthalmology, Liaquat University Eye Hospital Hyderabad, Sindh - Pakistan, from July 2002 to December 2004 (Thirty months). PATIENTS AND METHODS: A total of 200 patients with chronic allergic conjunctivitis using topical steroids (Betamethasone, Dexamethasone, Prednisolone) for more than six months were examined. A thorough examination including visual acuity, Goldmann applanation tonometry, Schiot’z tonometry, Gonioscopy, slit lamp examination and dilated Ophthalmoscopy were performed. RESULTS: Out of 200 patients examined, fifteen (7.5%) were found having raised intraocular pressure (secondary glaucoma) due to prolonged use of topical steroids. The rise of intraocular pressure was bilateral in three patients (1.5%), and unilateral in twelve patients (6.0%). The topical steroids were discontinued. One patient with vernal conjunctivitis using topical steroids since more than two years developed left optic disc pallor with constriction of visual field, and posterior sub capsular cataract. The intraocular pressure was not controlled by ocular hypotensive agents, and glaucoma filtration surgery was advised. CONCLUSION: This study identifies the risk of intraocular pressure elevation in patients with allergic conjunctivitis, using topical steroids for longer periods. Long term use of topical and systemic steroids produces secondary open angle glaucoma similar to chronic simple glaucoma. We can conclude that Dexamethasone and Prednisolone are possible risk factors for producing glaucoma.

Effect of Apraclonidine Versus Dorzolamide on Intraocular Pressure After Phacoemulsification

To investigate the efficacy of 1% apraclonidine hydrochloride and 2% dorzolamide hydrochloride in controlling postoperative intraocular pressure elevation in patients undergoing phacoemulsification. A prospective, randomized, double-blind, placebo-controlled study was conducted. Seventy-five patients were randomized to receive either 1% apraclonidine hydrochloride, 2% dorzolamide hydrochloride, or artificial tears immediately after uncomplicated phacoemulsification. Intraocular pressure was measured by Goldmann applanation tonometer 1 to 3 hours preoperatively and 24 hours and 5 days postoperatively. Mean intraocular pressure measured at 24 hours and 5 days after surgery was not significantly different between groups. None of the patients had an elevated intraocular pressure of 30 mm Hg or higher. No marked difference was observed in patient age, preoperative intraocular pressure, mean ultrasound time, degree of nuclear hardness, and amount of postoperative intraocular inflammation between groups. Uneventful phacoemulsification involving meticulous cortical and viscoelastic removal does not cause a significant increase in intraocular pressure 24 hours following surgery.

Dorzolamide Influences the Autoregulation of Major Retinal Vessels Caused by Artificial Intraocular Pressure Elevation in Patients with POAG: A Clinical Study

Purpose: The study investigated whether dorzolamide influences the autoregulatory behavior of major retinal arterioles in glaucoma patients via a moderate perfusion pressure reduction. Methods: The study included one eye each of 12 untreated patients with a primary open-angle glaucoma (POAG) (age 60.8 ± 8.3, IOP 22.3 ± 6.5 mmHg). Changes in the diameter of a retinal artery segment before (120 s), during (100 s), and after (380 s) artificial IOP elevation to 38 mmHg for 100 s were recorded continuously by means of a Retinal Vessel Analyzer. The measurement was repeated after 4-week treatment with dorzolamide eye drops t.i.d. Results: Ocular perfusion pressure (mmHg) was reduced by the intraocular pressure (IOP) elevation from 58 (± 10) to 41 (± 11) in the pretreatment examination and from 60 (± 8) to 40 (± 8) posttreatment (differences between the examinations n.s.). Before IOP elevation, the arterial diameter was found to be +1.7 ± 3.5% greater in the posttreated eyes than in the pretreated eyes (p < 0.02). During IOP elevation, the arterial diameter decreased by −1.8% ± 3.8 in the pretreated eyes, whereas dilatation by +1.4% ± 2.5 was observed in the posttreated eyes (p = 0.02). At the end of the observation period following IOP elevation, the vessel diameter in the pretreated eyes had increased by +1.8% ± 4.2, whereas in the posttreated eyes it had decreased by −1.7% ± 3.0. On average, dorzolamide reduced IOP by −5.6 mmHg (p = 0.001). Conclusions: The arterial diameter dilatation during IOP elevation in dorzolamide-treated eyes could be an accelerated counter-regulation on the induced elevated IOP and could constitute an additional therapeutic effect.

Molecular Clock Mechanisms and Circadian Rhythms Intrinsic to the Heart

Circadian rhythms are the external expression of an internal clock mechanism that measures daily time.1 Periodic environmental cues entrain or set the circadian clocks. The daily light-dark cycle represents the most dominant and potent entraining stimulus in mammals. An entrained clock coordinates physiological events to the 24-hour day. Normally, cardiovascular or hemodynamic parameters, such as heart rate and blood pressure, exhibit variations consistent with circadian rhythm. Additionally, several types of acute pathological cardiac events exhibit circadian or at least diurnal rhythm patterns. Specifically, the incidences of acute myocardial infarction, myocardial ischemia, out-of-hospital cardiac arrest, ventricular tachycardia, postmyocardial infarction, and sudden death in heart failure all vary according to the time of day.2–5 Also, diurnal rhythms can influence degree and form of cardiac hypertrophy and remodeling.6,7 For instance, the degree of nocturnal blood pressure elevation in patients with systemic hypertension correlates with the severity and concentricity of left ventricular hypertrophy.8,9 Investigators postulate that these circadian or diurnal variations depend on centrally mediated autonomic or neurohumoral activation. However, peak incidence for some acute events, such as sudden death, does not temporally correspond to the circadian sympathetic activation. Thus, alternative inputs or mechanisms for these rhythm patterns have been postulated. Regardless of the input, the intrinsic clock mechanism must respond and regulate some of the circadian rhythms within the heart itself. The intrinsic response elements for the putative external circadian inputs had not until recently been identified or characterized in the heart.10,11 Circadian rhythms are controlled by a transcriptional feedback system fluctuating as a function of the light-dark cycle. Molecular control of a circadian clock mechanism has been described in detail in the fruit fly.12 Similarities between the core clock mechanisms in fruit flies and mice occur with both exhibiting interlocking positive and negative transcriptional and translational …