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Biomedical subjects

R G Marks

Publications and source records attributed to R G Marks.

At least 73 records · Page 4Linked to original sources
PubMed1987

Drug use in an ambulatory elderly population: a five-year update.

Drug usage was studied in an ambulatory elderly population in Dunedin, Florida. Prescription and nonprescription drug use in these 2834 participants was compared with use during a period five years earlier. The average number of medications increased from 3.2 in 1978-80 to 3.7 in 1983-85. The most commonly prescribed medications in this population were hydrochlorothiazide-triamterene (13.5 percent), digoxin (9.6 percent), and hydrochlorothiazide (8.4 percent). There was a large increase in the use of nutritional supplements in the past five years, with 18.0 percent of these subjects reporting the use of vitamin E and 15.7 percent taking vitamin C. The general philosophy in geriatrics is to use the fewest drugs possible; however, it appears that the elderly are, in fact, receiving an increasing number of medications.

Age Factors↗
PubMed1986

Symptom prevalence in the elderly. An evaluation of age, sex, disease, and medication use.

Prevalence of reported symptoms was studied in 1927 women and 1140 men over 65 years of age in an ambulatory health screening program. Reports of 28 common symptoms were obtained from a standardized questionnaire completed by participants at the time of their fourth annual visit to the program. A comparison was made of the prevalence of specific symptoms by sex, age, disease states, and drug use patterns. The most common symptoms reported by women were nocturia (80.4%), swollen feet or ankles (30.5%), cold feet and/or legs (28.6%), and irregular heartbeat (23.2%), whereas men complained most often of nocturia (79.8%), irregular heartbeat (24.8%), cold feet and/or legs (23.6%), and tinnitus (23.1%). Women reported a mean of 3.99 symptoms compared with 3.22 reported by men (P less than .0001). In women their was a statistically significant association for most symptoms in subjects reporting the use of medication compared with a group who did not use medication. In men the use of medication was less highly correlated with reports of symptoms. Nearly 100% of participants reported having at least one disease state. The number of symptoms reported was strongly related to the number of disease states, and after adjusting for diseases, women reported more symptoms than men. The best predictor of symptom prevalence was the number of disease states followed by the number of drugs used and then age.

Age Factors↗
PubMed1986

Vitamin E effect on symptoms and laboratory values in the elderly.

The effect of vitamin E use on selected medical disorders and laboratory parameters was studied in a large ambulatory elderly population. Information obtained from a standardized questionnaire concerning reports of numerous clinical disorders, such as hypertension, fatigue, and vaginal bleeding, was used to determine whether the use of vitamin E predisposed to those conditions. During a 2-year period, information was available on 369 vitamin E users and 1,861 non-users. No differences were noted in the prevalence of reported clinical disorders between the two groups, except that men using vitamin E complained more often of shortness of breath (p less than .04) and angina (p less than .03). There were no significant differences between vitamin E users and controls in any hematologic parameters studied. After the groups had been adjusted for age and sex differences, only one biochemical parameter, serum glutamic-oxaloacetic transaminase (SGOT) in men, was found to be significantly different in vitamin E users as compared with controls. Use of vitamin E by the participants in this study appeared to have little influence on clinical disorders or hematologic or biochemical parameters.

Aged↗
PubMed1985

Two-year results of radial keratotomy.

This article presents the one- and two-year results of radial keratotomy on the first 386 surgeries performed by one of us (H.S.). Follow-up visits were obtained on 285 (74%) of these eyes. The mean spherical equivalent before surgery was -4.3 diopters, average keratometry was 44.11 D, and 75% of eyes had uncorrected distance acuity of 20/400 or more. Average change in spherical equivalent was 3.5 D at two years. Uncorrected visual acuity was at least 20/40 in 70% of eyes examined at two years, and at least 20/20 in 26%. Refractive, keratometric, and visual results all were stable at 12 months and showed no significant change from one to two years after surgery. Of the patients in this study, 11.9% required second procedures and 8% of surgeries had perforations, but none with negative sequelae. The results of our analysis indicate that radial keratotomy surgery is safe, effective, and with stable results two years after surgery.

Adult↗
PubMed1985

Mortality, morbidity, and cost-accounting related to coronary artery bypass graft surgery in the elderly.

The purpose of this study was to document early mortality, perioperative complication rate, duration of hospitalization, and costs related to coronary artery bypass graft (CABG) surgery in the elderly. Arbitrarily, elderly patients were defined by age greater than or equal to 65 years; younger patients were less than or equal to 60 years old. A detailed list of specific perioperative complications was analyzed. Early (30-day) mortality was similar between groups, while 120-day mortality was higher among elderly compared with younger patients (7.6% versus 1.3%; p = 0.05). The number of elderly patients with 1 or more complications was also higher than among the younger patients (62% versus 43%; p = 0.05). When the incidences of atrial arrhythmias and transient psychoses were considered minor complications and excluded from consideration, the incidence of major complications was higher in the elderly: 41 major events among 76 younger surviving patients compared with 89 major complications in 61 older surviving patients (p = 0.001). Time spent in the intensive care unit and the duration of postoperative hospitalization were also greater in the elderly (p = 0.01 and p = 0.001, respectively). Finally, the elderly group incurred greater costs than the younger patients (p = 0.03). The likelihood of increased perioperative morbidity in elderly patients is documented in this study. Also, it appears that the increased frequency of complications in elderly patients is associated with a longer hospital stay and greater financial expense. Consequently, the careful preoperative evaluation of these patients, including cautious patient selection, assumes greater importance. After CABG procedures, the highly symptomatic elderly patient may experience dramatic relief of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1985

Intraocular lens design for the neodymium:YAG laser.

Phacoemulsification was performed on both lenses of 24 rabbits. One eye received a lens implant with a convex-plano optic; the fellow eye received an implant with a convex-concave optic which separated the posterior surface of the implant from the posterior capsule by 0.2 mm, 0.3 mm, or 0.4 mm. A YAG laser capsulotomy was performed on all eyes immediately following surgery and an assessment of both microscopic and macroscopic YAG-induced lens damage was made. The meniscus optics with their capsule-implant separation showed significantly less YAG-induced damage than their convex-plano counterparts without this separation. Increasing the amount of capsule-implant separation beyond 0.2 mm did not enhance the degree of protection from YAG-induced damage.

Animals↗
PubMed1985

Evaluating the predictability of radial keratotomy.

The predictability of radial keratotomy surgery for both the steel and diamond knife cases is evaluated in a long-term prospective study. Over 500 cases are used to build predictability models for both types of knives at 1, 3, 6, and 12 months after surgery. A predictability model is also presented at 24 months after surgery for the steel knife. R2 values range from 54 to 80% for the various models. Over 75% of cases are predicted within 2 D of their obtained result for the steel knife at all time periods and over 78% for diamond knife cases. Each model is also evaluated for how well it predicts future cases.

Age Factors↗
PubMed1985

Antianxiety drugs and central nervous system symptoms in an ambulatory elderly population.

Antianxiety agents' effects on the reported frequency of fainting, dizziness, loss of consciousness, and bone fractures were studied in a large ambulatory elderly population. The frequency of these symptoms in participants using seven different antianxiety drugs and that of a control group were compared. Dizziness and episodes of loss of consciousness and falls were reported more frequently in women using these drugs compared with controls (p less than 0.04 and p less than 0.01, respectively). There was an increase in reported bone fractures (12.1 percent to 9.4 percent) in women using antianxiety agents when compared with controls. All central nervous system symptoms were reported more frequently in participants using these drugs when compared with controls. This study suggests that chronic use of antianxiety agents in elderly patients may result in disabling central nervous system side effects.

Aged↗
PubMed1985

The incidence of rebleeding in traumatic hyphema.

A collaborative, retrospective study of 371 consecutive hyphema patients reveals an overall 3.5% incidence of rebleeding of without the use of antifibrinolytic agents. Numerous factors were reviewed on each patient, including age, sex, race, grade of hyphema, disposition, and the use of topical or systemic medications. Thirty percent of the patients were treated on an outpatient basis. The low incidence of rebleeding, particularly in less severe hyphemas (less than half the anterior chamber volume), does not support the routine use of systemic antifibrinolytics or corticosteroids.

Adolescent↗
PubMed1984

Visual, refractive, and keratometric results of radial keratotomy. One-year follow-up.

Ongoing prospective evaluation of radial keratotomy was conducted on 156 eyes of the first 101 consecutive patients. We did a one-year follow-up and compared previously reported six-month findings. All eyes were examined both six months and one year after surgery. Findings obtained by an independent examiner both before and after surgery correlated highly with findings obtained in the surgeon's office. One year after surgery, mean change in spherical equivalent was +4.7 diopters; overall uncorrected distance acuity was 20/20 in 49% of cases and at least 20/40 in 76% of cases. Fifty-eight percent of eyes were within 1.0 D of emmetropia. Visual results showed slight general improvement between six and 12 months; refractive results were stable, except that excessive overcorrection was found to decrease. In this series, radial keratotomy seemed safe and effective one year after surgery.

Astigmatism↗
PubMed1984

Psychosocial findings in radial keratotomy patients two years after surgery.

In a psychosocial study of patients who participated in an evaluation of the visual, refractive and keratometric results of radial keratotomy, respondents stated that their primary reasons for electing the operation related to anticipated changes in vision. Improving appearance was not reported as a primary reason for seeking radial keratotomy by these patients. When asked two years after surgery if their vision had improved, remained the same, or worsened, 94.3% reported improvement over preoperative vision. About 40% still wear corrective lens, 26% full time and 14% only part of the time. Most patients (84.1%) reported overall satisfaction with the surgical outcome. Patient satisfaction was strongly related to perceived improvement of vision after surgery, and not to patient self-esteem, to changes in appearance or lifestyle brought about by the operation, or to having a particular physician perform the surgery.

Adaptation, Psychological↗
PubMed1984

Radial keratotomy: an overview of the Kansas City study.

The first 290 consecutive eyes (192 patients) to undergo radial keratotomy by one surgeon were evaluated prospectively. All had had complete preoperative evaluation and 269 (93%) were examined one or more years after surgery. Preoperatively, all patients except one had worse than 20/100 uncorrected visual acuity, 65% had less than 20/400, and mean spherical equivalent (SE) was -4.8 diopters. One year postoperatively, 40% of the patients had uncorrected visual acuity of 20/20 or better and 83% had 20/40 or better. The mean change in SE after 1 year was 5.0 diopters, and 60% of eyes were within 1 diopter of emmetropia. Keratometric changes paralleled refractive changes, and both appeared stable within 1 to 3 months. Complications were few and most were transient or well-tolerated. One case of presumably viral disciform keratitis occurring 8 months postoperatively had a three Snellen line decrease in best-corrected acuity 1 year postoperatively. Factors affecting refractive outcome were studied using stepwise multiple regression analysis. Size of the optical zone, depth of incision, patient age, patient sex, intraocular pressure, number of incisions, preoperative average keratometry, and corneal diameter were each found to affect clinical outcome significantly.

Adolescent↗
PubMed1984

Central nervous system symptoms of elderly subjects using antihypertensive drugs.

The effects of antihypertensive agents on the frequencies of reported fainting, dizziness, losses of consciousness, and bone fractures were studied in a large, ambulatory elderly population. The frequencies of these symptoms were compared for subjects who used one or more of nine different antihypertensive agents and for subjects who were not using these medications and who served as a control group. Over 40 per cent of the total population were using at least one of the nine drug groups. Women who used antihypertensive medications reported significantly more fainting (P less than 0.001), dizziness (P less than 0.005) and "blacking-out spells" (P less than 0.002) but significantly fewer bone fractures (P less than 0.02) compared with women who were not using such medication in the control group. For men, the use of only one drug group, propranolol, was associated with a significant increase in fainting and dizziness but not blacking-out spells compared with men in the control. These results suggest that elderly persons may be subject to a variety of central nervous system side effects induced by antihypertensive drugs.

Aged↗
PubMed1983

Visual, refractive, and keratometric results of radial keratotomy.

Prospective evaluation of radial keratotomy was conducted on 156 consecutive eyes of 101 patients. Before surgery, mean spherical equivalent (SE) was -5.0 diopters and uncorrected distance acuity was 20/200 or worse in 96% of eyes. All eyes were examined six months after surgery. Overall six-month postoperative distance acuity was 20/20 in 43% and 20/40 or better in 73% of eyes; 51% of eyes were within 1.0 D of emmetropia; mean change in SE was +4.8 D. When preoperative myopia was less than 6.0 D, six-month uncorrected acuity was 20/20 in 53% and 20/40 or better in 84% of eyes; 63% were within 1.0 D of emmetropia. Visual, refractive, and keratometric findings appeared stable at six months. Predictability appeared best when preoperative myopia was less than 6 D. Complications were few, none resulted in reduced best-corrected acuity, and most were transient and/or well tolerated. In this series, radial keratotomy appeared safe short-term. Ongoing evaluation is being conducted to determine long-term safety and efficacy.

Adult↗
PubMed1983

Antacid use in an ambulatory elderly population. A report from Dunedin Program.

Antacid use was studied in a population of 3192 elderly ambulatory subjects. Antacids were used by 18.6% of women and 12.9% of men. Three common antacid products accounted for 63.8% of all antacids used by these subjects. Serum phosphorus concentrations of participants using aluminum antacids were significantly lower than in a nonantacid user control group (P less than 0.02). Total protein and serum calcium concentrations of subjects using aluminum and magnesium combination antacid products were significantly lower than the control group (P less than 0.001 and P less than 0.04). Men using calcium carbonate antacids reported diarrhea significantly more frequently than control subjects.

Age Factors↗
PubMed1983

Haematological and biochemical laboratory values in an ambulatory elderly population: an analysis of the effects of age, sex and drugs.

Haematological and biochemical test results of 2242 ambulatory, elderly subjects in a health screening programme were used to study normal ranges for these values. A large percentage of leucocyte and erythrocyte counts and haemoglobin and haematocrit values were below the reference range of the laboratory performing the tests. Over 25% of erythrocyte counts were below the lower limit of normal, while in men 50% of mean corpuscular haemoglobin values were above the upper limit of normal. A large percentage of serum potassium concentrations were below the lower range of normal, while a high percentage of blood urea nitrogen, creatinine, triglycerides, and lactic dehydrogenase concentrations fell above the upper limit of normal. When subjects using drugs were compared to a nondrug-taking group, significant differences were found in serum potassium, chloride, carbon dioxide, creatinine, uric acid and serum glutamic oxaloacetic transaminase concentrations.

Age Factors↗