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A prospective study of 83 eyes in 76 consecutive patients undergoing keratoplasty for keratoconus is presented in which 1% atropine was routinely given at the end of surgery. No case of permanent mydriasis was seen. The syndrome described in the literature of fixed, dilated pupil after the use of atropine in keratoplasty no longer seems to exist and the warning against strong mydriatics appears unwarranted.
OBJECTIVE: Target organ damage (TOD) in chronically treated hypertensives is related to effective blood pressure (BP) control. The aim of this study was to evaluate the prevalence of cardiac and extracardiac TOD in patients with refractory hypertension (RH) compared with well-controlled treated hypertensives (C). METHODS: Fifty-four consecutive patients with RH (57 +/- 10 years), selected according to WHO/ISH guidelines definition, and 51 essential hypertensives (55 +/- 10 years) with satisfactory BP control obtained by association therapy, underwent the following procedures: (1) clinic BP measurement; (2) blood sampling for routine chemistry examinations; (3) 24 h urine collection for microalbuminuria; (4) non-mydriatic retinography; (5) echocardiogram; (6) carotid ultrasonogram. In order to exclude 'office resistance' (defined as clinic BP > 140/90 mmHg and average 24 h BP </= 125/79 mmHg), all patients with RH were subjected to 24-hour ambulatory BP monitoring. RESULTS: Both groups were similar for age, gender, body surface area, smoking habit and duration of hypertension, glucose, creatinine and lipid levels. By definition, clinic BP was significantly higher in RH than C (161 +/- 19/96 +/- 9 versus 127 +/- 6/80 +/- 5 mmHg, respectively, P < 0.01). The increased prevalence of left ventricular hypertrophy (LVH) and carotid intima-media (IM) thickening (40 versus 12%, P < 0.01, according to a non-gender-specific partition value of 125 g/m2; and 36 versus 14%, P < 0.01, according to IM thickness > or =1.0 mm, respectively); a higher prevalence of carotid plaques (65 versus 32%, P < 0.05), a more advanced retinal involvement (grade II and III, 73 and 5% versus 38 and 0%, P < 0.01) and a greater albumin urinary excretion (22 +/- 32 mg/24 h versus 11 +/- 13 mg/24 h, P < 0.01) were found in RH compared to C. CONCLUSIONS: Our study suggests that RH is a clinical condition associated with a high prevalence of TOD at cardiac, macro- and microvascular level and consequently with high absolute cardiovascular risk, which needs a particularly intensive therapeutic approach aimed to normalize BP levels and to induce TOD regression.
Since increased alpha-adrenergic reactivity may participate in the pathophysiology of essential hypertension, methods for accurately assessing in vivo alpha-receptor sensitivity in humans might be useful. The goals of this study were to employ previously used methods, namely pupillometry and local forearm intraarterial infusions, to assess alpha-receptor sensitivity, create an in vivo environment of decreased sympathetic drive (plasma norepinephrine) and increased alpha-receptor number (platelet alpha 2), in which increased alpha-receptor sensitivity to exogenous agonists might occur. Five patients with minimally elevated blood pressure (139 +/- 5/90 +/- 4 mm Hg) while on diuretic monotherapy completed assessment of biochemical and physiologic variables on diuretic alone and again on diuretic and guanadrel. Guanadrel plus diuretic compared with diuretic alone lowered the seated diastolic and standing systolic and diastolic blood pressure. Heart rate was decreased about 10 beats/min. Baseline supine norepinephrine was reduced an average of 40% (from 281 +/- 23 to 168 +/- 16 pg/ml, p = 0.03), and platelet alpha 2-receptors were increased roughly 40% (from 178 +/- 34 to 250 +/- 54 fmol/micrograms, p = 0.07). Despite the expected decrease in sympathetic drive and increase in alpha-receptors (platelet alpha 2), the pupillary mydriatic response to phenylephrine and the forearm vasoconstrictor response to intraarterial norepinephrine were not augmented. The failure to detect increased physiologic responsiveness in the presence of decreased norepinephrine and increased alpha 2-receptor number lends itself to multiple explanations which need to be tested in future research.(ABSTRACT TRUNCATED AT 250 WORDS)
Twenty-three subjects with noninsulin-dependent diabetes mellitus (NIDDM) and 23 age- and sex-matched controls were tested for sympathetic denervation of the iris dilator by comparing the mydriatic effect of the combination of 1% phenylephrine and 1% tropicamide with that of 1% tropicamide alone. Most of the diabetic subjects had no clinical signs of severe diabetic complications. Nine diabetics and two controls showed sympathetic denervation, defined as a 1 mm or greater dilation due the addition of 1% phenylephrine. One of those two controls had a recent history of vascular headache. The diabetics with pupillary neuropathy had higher glycosylated hemoglobin percentages and a history of higher fasting blood sugars (FBS's) than the diabetics with normal pupils. Our results show that pupillary neuropathy can develop in persons with diabetes, often before the other complications of diabetes become manifest.
An alpha-adrenergic blocking drug, dapiprazole, is now marketed in eyedrop form. Dapiprazole is being promoted as an agent suitable for reversing the diagnostic mydriasis produced by tropicamide or tropicamide and phenylephrine. The mechanism of action of dapiprazole is thought to be the same as that of moxisylyte (thymoxamine). The human pharmacokinetics for these drugs are reviewed and compared to pilocarpine. Published data indicate that either dapiprazole (0.5%) or moxisylyte (0.5%) enhance recovery from the mydriasis produced by tropicamide, phenylephrine, or their combination. However, because the published studies differ substantially in the doses of these mydriatics or in the miotics actually used, it is not possible to make any firm recommendations on how many drops of these new miotics should be instilled.
This study tested the hypothesis that the Type A behavior pattern and its components are associated with increased activity of the sympathetic nervous system. To do this, we employed two new markers of sympathetic tone--pupil size and platelet catecholamine content. Thirty-three healthy males were blindly rated for Type A behavior and verbal stylistic components by Structured Interview. Adrenergic tone to the pupils was assessed from pupil diameter recorded by infrared television pupillometry, and pupil alpha-adrenergic sensitivity was estimated from mydriatic response to ophthalmic phenylephrine. Platelet epinephrine and norepinephrine contents were assayed because these levels are associated with chronic, long-term circulating catecholamine levels. The results showed Type As had consistently larger pupil diameters than Type Bs (p = 0.03, 0.03, and 0.01). There was no difference in pupillary response to phenylephrine instillation between groups. Platelet epinephrine content was greater in Type A subjects (chi 2 = 4.25, p less than 0.04, t = 1.6, p = 0.06). Only the component of explosiveness was modestly associated with resting pupil size, and no components significantly predicted platelet catecholamines. We conclude that the results of these two new markers of autonomic activity, namely, pupil size and platelet epinephrine, suggest that Type A behavior is characterized by increased sympathetic nervous system tone although we cannot rule out the possibility of decreased activity of the parasympathetic nervous system.
The ophthalmologist performing cataract surgery today has a wide variety of options in terms of both surgical technique and available surgical adjuncts, which can greatly enhance the results of cataract surgery. Surgical adjuncts used both preoperatively and intraoperatively include mydriatics, pupil maintainers, oculopressor devices, viscoelastics, and intraocular irrigating solutions. Cataract surgical techniques continue to evolve, and phacoemulsification continues to increase in popularity. Hydrodissection and related techniques have become an important part of all types of extracapsular cataract surgery. In this article, we review cataract surgical techniques and the use of surgical adjuncts with an emphasis on the recent literature. Modifying surgical techniques to incorporate new developments and thus enhance results remains a distinct challenge to the ophthalmic surgeon.
This review of recent articles on ocular toxicology concentrates on undesirable effects on the eye induced by systemically used xenobiotics. These effects include the corticosteroid-induced glaucoma and cataracts (especially in children), chloroquine-induced heart block and retinopathy, its possible protection by platelet aggregating factor antagonists, oculopathy after intracarotid chemotherapy with nitrosyl-urea or cisplatin, ketoconazole-induced papilledema, cytarabine-induced photophobia, ethambutol HCl-induced visual deficits, psychotherapeutic-agent overdose-induced ocular bobbing, amiodarone-induced cataracts, and imipramine HCl-induced angle-closure glaucoma. Also reviewed are the role of hormone levels in diabetic retinopathy, the therapeutic use of clonidine for perioperative intraocular pressure spikes, the increase in ocular blood flow by pentoxifylline, and decrease by nicotine, the potential for the reduction in drop size of mydriatic medications, a theory for sulfonamide-induced myopia, and guidelines for animal models of ocular toxicity. No drug achieves ultimate efficacy or ultimate safety. Thus, the decision to employ a given therapy involves a physician's evaluation of its therapeutic index, the ratio between efficacy and toxicity.
1. Eight volunteers received in randomized order two 30 microliters drops of either 1% w/v cyclopentolate hydrochloride or a corresponding amount of cyclopentolate polygalacturonate in saline or in acetate buffer in one eye. Cyclopentolate concentrations in plasma were measured by a radioreceptor assay. 2. Peak plasma drug concentrations of about 3 ng ml-1 occurred within 30 min after all formulations. Occasionally, a second concentration peak in plasma, probably reflecting drug absorption from the gastrointestinal tract, was seen after 2 h. The mean elimination half-life of cyclopentolate was 111 min when all subjects and formulations were considered together. There were no statistically significant differences between the formulations with respect to the time-course of plasma drug concentration. 3. The maximal mydriatic effect was reached within about 15 min and was maintained for several hours, often being 1/3 of its peak value after 30 h. Similarly, an intense cycloplegic response was achieved within a few minutes, the peak changes in the near-point of vision being 9 to 10 dioptres. The cycloplegic response was more intense after one of the polygalacturonate complexes, especially at later time points.
The mydriatic response to eyedrops of the anticholinergic drug tropicamide at very low concentration (0.01%) was studied in subjects with Alzheimer's disease (AD, n = 10) and multi-infarct dementia (MID, n = 10). There was no significant difference in pupillary response between the two groups. The test is unlikely to be useful in differentiating different types of dementia.
OBJECTIVES: The aim of our study was to analyse, in a wide group of essential hypertensive patients without diabetes mellitus, the influence of metabolic syndrome (MS) (defined according to the criteria laid down in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults) on markers of preclinical cardiac, renal and retinal damage. DESIGN: Cross-sectional study. SETTING: Outpatient hypertension clinic. SUBJECTS AND METHODS: A total of 353 young and middle-aged hypertensives, free from cardiovascular and renal diseases (and 37% of whom had MS), underwent echocardiographic examination, microalbuminuria determination and non-mydriatic retinography. RESULTS: When compared with subjects without MS, hypertensive patients with MS exhibited more elevated left ventricular (LV) mass (either normalized by body surface area or by height elevated by a power of 2.7), higher myocardial relative wall thickness, albumin excretion rate (AER) and a greater prevalence of LV hypertrophy (57.7% vs. 25.1%; P < 0.00001), of microalbuminuria (36.2% vs. 19.3%; P = 0.002) and of hypertensive retinopathy (87.7% vs. 48.4%; P < 0.00001). These results held even after correction for age, 24-h blood pressures, duration of hypertension, previous antihypertensive therapy, and gender distribution. The independent relationships between LV mass and MS, and between AER and MS, were confirmed in multivariate regression models including MS together with its individual components. CONCLUSIONS: MS may amplify hypertension-related cardiac and renal changes, over and above the potential contribution of each single component of this syndrome. As these markers of target organ damage are well-known predictors of cardiovascular events, our results may partly explain the enhanced cardiovascular risk associated with MS.
A 4.5 year old boy with cerebral palsy presented with seizures associated with facial flushing and tachycardia following the instillation of 1% cyclopentolate, a commonly used mydriatic in paediatric practice. He had no prior history of convulsions. This case demonstrates the uncommon, though serious, atropine-like side effect of cyclopentolate eyedrops (Cyclogyl, Alcon) in usual dosage in a brain damaged child without an epileptic focus.
Symptoms that persist after operations for angle-closure glaucoma arise from different causes. In the presence of open peripheral iridectomies miotics may be beneficial or may close angles; wide pupil dilatation by phenylephrine used to diminish posterior synechiae may close angles; cycloplegic mydriatics will close some angles and open others. Unexpected bizarre reactions to eye drops may occur. Persistent chronic glaucoma will be more common after laser iridotomy than after correctly assessed filtering operations. The importance of gonioscopy in diagnosis and management is emphasised.
PURPOSE: To highlight the association of uveitis with the use of rifabutin. METHODS: Retrospective study of two patients with acute anterior uveitis. RESULTS: Both patients were receiving rifabutin for treatment of atypical Mycobacterium infection associated with AIDS when they developed unilateral acute anterior uveitis and arthritis. The inflammation resolved and vision improved with introduction of topical corticosteroids, mydriatics and cessation of rifabutin treatment. CONCLUSION: Use of rifabutin with clarithromycin may precipitate acute uveitis in patients with AIDS being treated for systemic Mycobacterium avium complex infection. Uveitis produced by rifabutin may be analogous to Herxeimer reaction as seen in syphilis. Clarithromycin and fluconazole elevate levels of rifabutin due to inhibition of metabolism through cytochrome p-450 pathway. The differential diagnosis includes Reiter's syndrome, syphilis causing uveitis, metastatic endophthalmitis, and direct HIV-related uveitis.
PURPOSE: To determine baseline eye care utilization by older Victorians in order to assess change in 2 years after an eye health promotion campaign. METHODS: A letter of invitation to participate was sent to all people aged 70-79 years in randomly selected Melbourne postcode areas. A questionnaire was designed to allow gathering of eye health-related information. Eye exams included autorefraction, frequency doubling technology and non-mydriatic fundus photography. Results were compared with the Melbourne Vision Impairment Project . RESULTS: A total of 1695 people with a mean age of 74 years were recruited. The overall proportion with visual impairment was 8% (134/1695), of which 27% (36/134) was due to non-refractive causes. Only 31% (11/36) of visually impaired people knew about low-vision services, of whom 20% (7/36) had used them. Of all people with diabetes, only 52% (96/184) had a dilated eye exam within the recommended 2 years (Melbourne Vision Impairment Project 44%). CONCLUSIONS: Compliance rates with recommendations for 2-yearly eye exams for people with diabetes have not improved since the last major eye health study in Victoria 10 years ago. The same is true for the rate of undiagnosed glaucoma, suggesting that messages about eye examinations need to be promoted for older people at high risk of vision loss, for example, those with diabetes and at risk of vision loss from glaucoma.
The relative cost and cost-effectiveness of different methods of screening diabetic patients for sight-threatening retinopathy are assessed. The resource costs per screening visit, both to the health service and to patients, of ophthalmoscopic examination by primary screeners including general practitioners, hospital physicians, and ophthalmic opticians are estimated together with those of a similar screening test by ophthalmological clinical assistants. The total resource cost per screen of screening using non-mydriatic photography is also estimated. Using estimates of sensitivity, specificity, and prevalence generated in the screening of 3318 diabetic patients in three UK centres, the relative cost-effectiveness of screening methods is estimated in terms of their cost per true positive case detected. On the assumption that a patient makes a special trip for eye screening, the cost per true positive case detected for primary screeners ranges from 633 pounds for a GP-screened group in one centre to 1079 pounds for another GP-screened group in a second centre; the cost per true positive case detected of photography ranges from 497 pounds for a camera that is taken to general practices in one centre to 1546 pounds for a hospital-based camera. Relative cost-effectiveness changes if, in some contexts, the screening can take place without requiring an additional patient visit, and is strongly related to the relative sensitivity of the screening methods and to the prior probability (prevalence or incidence) of retinopathy in the diabetic population.
The Health Technology Board Scotland (HTBS) have issued recommendations for eye screening in patients with diabetes. These are based on evidence-based clinical studies. Evidence-based studies do not answer all the practical issues, and some conclusions have thus been extrapolated from the known evidence base. Other factors such as patient issues, organizational issues and cost effectiveness have also been incorporated into the recommendations. HTBS recommend single-field digital retinal photography. Retinal photography best addresses the issues of adequate sensitivity and accountable quality assurance. Non-mydriatic photography is recommended, followed by immediate use of dilating eye drops if it is unsuccessful, followed by slit-lamp examination if both of these approaches fail. An independent grading scheme has been established, which is similar to the 'Global', and compatible with the National Screening Committee (NSC) grading scheme. The rationale for these recommendations, and debate behind some of the decisions, is laid out in this article.
The study examines to what degree the output of the Canon Auto-ref R1 infra-red (IR) optometer is affected by variations in pupil size for both static measurement of refractive error and for continuous recording of accommodation when switched to its modified mode of operation. In the normal static mode of operation the measurement of refractive state simply depends on the position of the peak photodetector output for each of three meridians: it does not depend on signal amplitude and hence pupil size. However, in continuous mode the actual output of a single photodiode is measured and the measurement is susceptible to changes in pupil size that occur within the area of the exit pupil utilized by the instrument. Using static and dynamic recording on model and human eyes the study shows that a 10% reduction in output signal relative to the maximum output level (for a constant stimulus) occurs for pupil sizes of 3.9 mm. The relatively small exit pupil has important advantages with regard to the use of mydriatic drugs and task-induced changes in pupil diameter.