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Subjective Responses (subjective + response)

Distribution by Scientific Domains

Medical Sciences	90%
2 Other Domains	10%

Selected Abstracts

Subjective Response to Alcohol: A Critical Review of the Literature

ALCOHOLISM, Issue 3 2010
Meghan E. Morean
Background:, Subjective response to alcohol (SR), which reflects individual differences in sensitivity to the pharmacological effects of alcohol, may be an important endophenotype in understanding genetic influences on drinking behavior and alcohol use disorders (AUDs). SR predicts alcohol use and problems and has been found to differ by a range of established risk factors for the development of AUDs (e.g., family history of alcoholism). The exact pattern of SR associated with increased risk for alcohol problems, however, remains unclear. The Low Level of Response Model (LLR) suggests that high-risk individuals experience decreased sensitivity to the full range of alcohol effects, while the Differentiator Model (DM) asserts that high risks status is associated with increased sensitivity to alcohol's positive effects but decreased sensitivity to negative effects. Aims:, The current paper (1) reviews two prominent models of subjective response, (2) reviews extant laboratory-based research on subjective response, (3) highlights remaining gaps in our understanding and assessment of subjective response, and (4) encourages collaborative efforts to address these methodological and conceptual concerns. Methods:, This paper reviews studies which employed placebo-controlled and non-placebo-controlled alcohol challenge paradigms to assess a range of alcohol effects including impairment, stimulation, and sedation. Results:, The research literature provides at least partial support for both the LLR and DM models. High-risk individuals have been shown to have a reduced response to alcohol with respect to sedative or impairing effects, particularly on the descending limb of the blood alcohol curve (BAC). There is also evidence that ascending limb stimulant effects are more pronounced or operate differently for high-risk individuals. Discussion:, Despite commendable advances in SR research, important questions remain unanswered. Inconsistent results across studies may be attributable to a combination of an inadequate understanding of the underlying construct and methodological differences across studies (e.g., number and timing of assessments across the BAC, inclusion of a placebo condition). With respect to the underlying construct, existing measures fail to adequately distinguish between cognitive/behavioral impairment and sedation, aspects of which may be perceived positively (e.g., anxiolysis) due to their ability to act as negative reinforcers. Conclusions:, Addressing the concerns raised by the current review will be integral to making meaningful scientific progress in the field of subjective response. [source]

Donepezil in schizophrenia , is it helpful?

ACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2001
An experimental design case study
Objective:,To assess the clinical and cognitive effects of adding donepezil, a reversible acetylcholinesterase inhibitor, to the risperidone treatment of a high functioning stable out-patient with schizophrenia. Method:,Case study using an experimental ABAB design. Assessments were completed objectively by standardized neuropsychological tests and clinical rating scales and subjectively with visual analogue scales. Results:,Strong improvements attributable to donepezil were found for verbal fluency and the patient's subjective response. No adverse changes were noted in psychiatric symptoms or side effects. Conclusion:,Cholinergic enhancement as an adjunctive treatment in schizophrenia should be explored in larger controlled trials. [source]

REVIEW: Human and laboratory rodent low response to alcohol: is better consilience possible?

ADDICTION BIOLOGY, Issue 2 2010
John C. Crabbe
ABSTRACT If people are brought into the laboratory and given alcohol, there are pronounced differences among individuals in many responses to the drug. Some participants in alcohol challenge protocols show a cluster of ,low level of responses to alcohol' determined by observing post-drinking-related changes in subjective, motor and physiological effects at a given dose level. Those individuals characterized as having low level of response (LR) to alcohol have been shown to be at increased risk for a lifetime diagnosis of alcohol dependence (AD), and this relationship between low LR and AD appears to be in part genetic. LR to alcohol is an area where achieving greater consilience between the human and the rodent phenotypes would seem to be highly likely. However, despite extensive data from both human and rodent studies, few attempts have been made to evaluate the human and animal data systematically in order to understand which aspects of LR appear to be most directly comparable across species and thus the most promising for further study. We review four general aspects of LR that could be compared between humans and laboratory animals: (1) behavioral measures of subjective intoxication; (2) body sway; (3) endocrine responses; and (4) stimulant, autonomic and electrophysiological responses. None of these aspects of LR provide completely face-valid direct comparisons across species. Nevertheless, one of the most replicated findings in humans is the low subjective response, but, as it may reflect either aversively valenced and/or positively valenced responses to alcohol as usually assessed, it is unclear which rodent responses are analogous. Stimulated heart rate appears to be consistent in animal and human studies, although at-risk subjects appear to be more rather than less sensitive to alcohol using this measure. The hormone and electrophysiological data offer strong possibilities of understanding the neurobiological mechanisms, but the rodent data in particular are rather sparse and unsystematic. Therefore, we suggest that more effort is still needed to collect data using refined measures designed to be more directly comparable in humans and animals. Additionally, the genetically mediated mechanisms underlying this endophenotype need to be characterized further across species. [source]

Relationship between the cardiac response to acute intoxication and alcohol-induced subjective effects throughout the blood alcohol concentration curve

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2007
Caroline Brunelle
Abstract Rationale There is evidence to suggest that individual differences in the subjective response to alcohol exist and exaggerated cardiac response to alcohol has been suggested to be a marker of increased sensitivity to the stimulant properties of alcohol. Objectives The present investigation examines the relationship between cardiac reactivity to alcohol measured on the ascending limb of the Blood Alcohol Concentration (BAC) curve and the subjective stimulant and sedative effects of alcohol throughout the BAC curve. Methods The stimulant and sedative effects of alcohol anticipatory to alcohol and during the ascending and descending limbs of the BAC curve were evaluated using the Biphasic Alcohol Effects Scale in 39 male social drinkers. Results Cardiac response to ethanol measured on the ascending limb of the BAC curve was positively correlated with intoxicated stimulant effects at numerous time points during the ascending and descending limbs of the BAC curve (ps,<,0.01). No associations were found between cardiac change following alcohol and alcohol-related sedative effects at any time point. Conclusions Objective and subjective reports of stimulation post-alcohol ingestion may increase risk for problematic drinking. Copyright © 2007 John Wiley & Sons, Ltd. [source]

ALDH2 genotype-associated differences in the acute effects of alcohol on P300, psychomotor performance, and subjective response in healthy young Korean men: a double-blind placebo-controlled crossover study

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 3 2006
Hee-Young Shin
Abstract Background This study investigated the acute effects of alcohol on neurophysiological and psychomotor functions and the subjective response in healthy young Korean men according to the mitochondrial aldehyde dehydrogenase (ALDH2) genotype. Method A total of 24 males, half with ALDH2*1/*1 (active form) and the rest with ALDH2*1/*2 (inactive form), were selected through genotyping. In a double-blind placebo-controlled crossover design, each subject consumed either a 0.5,g/kg dose of alcohol or a placebo on two separate occasions, 1 week apart. The blood alcohol concentrations (BACs), P300 of event-related potential, psychomotor performance, and perceived feelings were assessed. Results Although the BACs were similar between the two groups, the effects of alcohol on P300 were greater overall in subjects with ALDH2*1/*2 than in subjects with ALDH2*1/*1. Psychomotor performance was more impaired after alcohol ingestion in subjects with ALDH2*1/*2 than in subjects with ALDH2*1/*1. The subjective response after alcohol ingestion was more negative in subjects with ALDH2*1/*2, compared to subjects with ALDH2*1/*1. Conclusions These results suggest that the ALDH2 polymorphism is an important factor in determining the effects of alcohol on various psychobehavioral functions. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Subjective Response to Alcohol: A Critical Review of the Literature

3D In-Vivo Optical Skin Imaging for Topographical Quantitative Assessment of Non-Ablative Laser Technology

DERMATOLOGIC SURGERY, Issue 3 2002
Paul M. Friedman MD
background. A new method for treating facial rhytides and acne scars with nonablative laser and light source techniques has recently been introduced. Given the inherent limitations of photographic and clinical evaluation to assess subtle changes in rhytides and surface topography, a new noninvasive objective assessment is required to accurately assess the outcomes of these procedures. objective. The purpose of this study was to measure and objectively quantify facial skin using a novel, noninvasive, In-vivo method for assessing three-dimensional topography. This device was used to quantify the efficacy of five treatment sessions with the 1064 nm QS Nd:YAG laser for rhytides and acne scarring, for up to six months following laser treatment. methods. Two subjects undergoing facial rejuvenation procedures were analyzed before and after therapy using a 30-mm, three-dimensional microtopography imaging system (PRIMOS, GFM, Teltow, Germany). The imaging system projects light on to a specific surface of the skin using a Digital Micromirror Device (DMDÔ Texas Instruments, Irving, TX) and records the image with a CCD camera. Skin Surface microtopography is reconstructed using temporal phase shift algorithms to generate three-dimensional images. Measurements were taken at baseline, at various times during the treatment protocol, and then at three and six-month follow-up visits. Silicone skin replicas (FLEXICO, Herts, England) were also made before and after the laser treatment protocol for comparison to In-vivo acquisition. results. Skin roughness decreased by 11% from baseline after three treatment sessions in the wrinkles subject, while a 26% improvement of skin roughness was recorded by 3D In-vivo assessment six months following the fifth treatment session. The subject with acne scarring demonstrated a 33% decrease in roughness analysis after three treatment sessions by 3D In-vivo assessment. A 61% improvement in surface topography was recorded 3-months following the fifth treatment session, which was maintained at the 6-month follow-up. conclusion. Three-dimensional In-vivo optical skin imaging provided a rapid and quantitative assessment of surface topography and facial fine lines following multiple treatment sessions with a 1064-nm QS Nd:YAG laser, correlating with clinical and subjective responses. This imaging technique provided objective verification and technical understanding of nonablative laser technology. Wrinkle depth and skin roughness decreased at the three and six-month follow-up evaluations by 3D In-vivo assessment, indicating ongoing dermal collagen remodeling after the laser treatment protocol. Future applications may include comparison of nonablative laser technology, optimization of treatment regimens, and objective evaluation of other aesthetic procedures performed by dermatologists. [source]

Domiciliary application of CryoCuff in severe haemophilia: qualitative questionnaire and clinical audit

HAEMOPHILIA, Issue 4 2008
A. I. D'YOUNG
Abstract., The acute management of haemophilic bleeding episodesin the home setting is based on the concept of immediate factor replacement therapy and the PRICE regime , an acronym representing the concepts of Protection, Rest, Ice, Compression and Elevation [1,2]. Integral to this regime is the application of cold therapy, and yet little is known regarding the safe periods of application, or the relative safety of cryotherapy devices such as the CryoCuffÔ when used in the home setting by patients suffering from severe haemophilia and related bleeding disorders. This study examines the subjective patient response to the application of the CryoCuffÔ device in the home setting in terms of the effect on pain, joint swelling and the return to ,pre-bleed status' of the knee, ankle or elbow in patients with severe haemophilia A/B or type III von Willebrand's disease (VWD) immediately following haemarthrosis, and any potential adverse effects related to the device or recommended duration of application as stated in the PRICE guideline (Fig. 1). Twelve patients, either with severe haemophilia A/B or with VWD were recruited and asked to use the CryoCuffÔ device as part of the PRICE regime immediately following the onset of knee-, ankle- or elbow bleeds for the next one year. Each subject was then sent a qualitative questionnaire to determine subjective responses to the device. All patients reported that the application protocol was easy to follow, they were able to apply the device as per the PRICE regime and they were able to tolerate it for the recommended period. Whereas, all the patients felt that the device had a significant impact on alleviation of pain and return to pre-bleed status, 78% of the patients felt that the device led to a significant reduction in swelling around the affected joint. There was no conclusive evidence that the device resulted in any reduction in the amount of factor used to treat the acute bleeding episode, however, no patients reported any perceived delay in achieving haemostasis or required extra factor replacement therapy consequent to the usage of the device. No other adverse effects were reported by participants in this study. Figure 1. ,The qualitative participant questionnaire, given following 1 year of unsupervised use in the home setting immediately following the onset of the symptoms of haemarthroses. [source]

Marginal mandibular nerve injury during neck dissection and its impact on patient perception of appearance

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 5 2009
FRACDS(OMS), FRCS(OMFS), Martin D. Batstone MPhil(Surg)
Abstract Background. Neck dissection to remove cervical lymph nodes is common practice in head and neck cancer management. The marginal mandibular nerve may be injured during neck dissection, particularly of level 1. The rate of injury to this nerve is underreported in the literature and its impact on patients is not well defined. Methods. An observational study was undertaken on patients who had undergone neck dissection over a 5-year period. The patients were examined for weakness and given a questionnaire related their perception of their appearance and their function. Results. Sixty-six patients were identified who had undergone 85 neck dissections. The rate of House Brackmann injury was 18% when analyzed by patient and 23% by neck. There were moderate correlations between observed injury and subjective responses to questions relating to ability to smile and weakness of the lower lip. Discussion. The rate of smile asymmetry following neck dissection is relatively high; however, severe injuries to the marginal mandibular nerve are uncommon. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source]

Stress reactivity: biological and subjective responses to the cold pressor and Trier Social stressors,

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2006
Aimee L. McRae
Abstract The cold pressor test (CPT) and Trier Social Stress Test (TSST) have been shown to reliably increase HPA activity; however, little research has compared responses to these stressors. In this study, biological (plasma cortisol and ACTH levels) and subjective (e.g., stress and mood) responses were compared in 31 subjects administered both the CPT and TSST. Subjects were diagnosed with alcohol dependence and post-traumatic stress disorder (PTSD) (n,=,11), alcohol dependence without PTSD (n,=,10), PTSD without alcohol use disorder (n,=,4), and neither PTSD nor alcohol use disorder (n,=,6). All subjects completed both the CPT and TSST. In all groups, the TSST elicited higher levels of ACTH and cortisol than the CPT, and the response time course differed between tasks. The TSST also produced lower mood ratings than the CPT. A comparison of all diagnosed groups with normal controls revealed group differences in ACTH responding for the CPT but not the TSST. The results suggest that the TSST results in a greater HPA response than the CPT; however, the CPT may have utility in diagnostically heterogeneous patients. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Effects of Stress and Alcohol on Subjective State in Humans

ALCOHOLISM, Issue 6 2002
Anna H. V. Söderpalm
Background: There is increasing evidence that stress and hypothalamic-pituitary-adrenal axis activation interact with drugs of abuse and influence drug-taking behaviors. Both studies with laboratory animals and survey data with alcohol users suggest that acute or chronic stressful events increase alcohol intake. One mechanism for the increase in alcohol intake may be that stress alters the subjective effects produced by the drug in ways that enhance the reinforcing properties of alcohol. Therefore, in this study we determined whether an acute social stressor alters subjective responses to ethanol in humans. The stressor was a modified version of the Trier Social Stress Test, an arithmetic task that increases cortisol levels. Methods: Twenty male volunteers participated in two laboratory sessions, in which they performed the Trier Social Stress Test on one session and no task on the other session, immediately before consuming a beverage that contained ethanol (0.8 g/kg in juice) or placebo (juice alone). Eleven subjects received ethanol on both sessions, and nine subjects received placebo on both sessions. Primary dependent measures were self-report questionnaires of mood states. Salivary levels of cortisol were obtained to confirm the effectiveness of the stress procedure. Results: Stress alone produced stimulant-like subjective effects. In the group who received ethanol, stress increased sedative-like effects and decreased stimulant-like effects. Conclusions: At this relatively high dose of ethanol, stress increased sedative effects of alcohol and did not increase desire for more alcohol. It is possible that in some individuals, the increased sedative effects after stress may increase the likelihood of consuming more alcohol. The effects of stress on consumption at this, or lower, doses of alcohol remain to be determined. [source]

Individual Differences in Responses to Ethanol and d-Amphetamine: A Within-Subject Study

ALCOHOLISM, Issue 4 2001
Louis Holdstock
Background: In some individuals, ethanol (EtOH) produces marked stimulant-like subjective effects resembling those of stimulant drugs, like d-amphetamine (AMP). In this study, we examined the neurochemical basis of these individual differences by examining the same subjects' responses to both EtOH and AMP. A positive correlation between subjects' responses to the two drugs may suggest that AMP and EtOH produce their stimulant-like subjective effects by a shared mechanism. Methods: Twenty-seven volunteers (17 male, 10 female), aged 21,35, received beverages or capsules containing EtOH 0.8 g/kg, AMP 10 or 20 mg, or placebo on four separate sessions in random order and under double-blind conditions. Various self-reported and objective drug effects were measured, including measures sensitive to subjective and cognitive stimulant-like effects. Results: EtOH and AMP produced their prototypical subjective and behavioral effects, including increased ratings of stimulant-like subjective effects, increased heart rate and blood pressure, and improved vigilance performance after AMP and increased ratings of sedative-like subjective effects, increased heart rate and blood pressure, and impaired vigilance performance after EtOH. Consistent with previous reports, there was substantial intersubject variability in subjective responses to EtOH: some subjects reported primarily stimulant-like effects, whereas others reported primarily sedative-like effects. To examine the relationship between these responses to EtOH and subjects' responses to AMP, correlations were examined between effects of EtOH and AMP. For all subjects together, there was a significant positive correlation between responses to EtOH and 20 mg AMP on the ARCI A scale (a measure of stimulant-like subjective effects;r= 0.41, p < 0.05). Among only those subjects who reported primarily stimulant-like effects from EtOH, the correlation between EtOH and AMP was 0.64 (p < 0.05). Conclusions: Subjects who experience pronounced stimulant-like effects from EtOH also report greater stimulant effects from AMP, suggesting that these effects may be mediated through similar mechanisms. These correlations between the drugs' effects were not observed on other measures, such as DSST or vigilance task performance or heart rate. This may indicate that these other effects are mediated by separate mechanisms. The study illustrates a novel approach to studying the neurochemical basis of drug effects. [source]

Serum 6-Beta-Naltrexol Levels Are Related to Alcohol Responses in Heavy Drinkers

ALCOHOLISM, Issue 9 2000
Mary E. McCaul
Background: There is strong evidence for the role of the endogenous opioid system in alcohol reinforcement and consumption; however, recent human laboratory studies and clinical trials have reported mixed effects of naltrexone (a nonselective opioid antagonist) on alcohol-related behaviors. This paper reports a secondary data analysis of a human laboratory study that examines the relationship between serum levels of 6-beta-naltrexol, the major, biologically active metabolite of naltrexone, and subjective effects of alcohol. Methods: The study used a within-subjects design to examine the effects of naltrexone (0, 50, and 100 mg/day) on subjective responses to alcohol (none, moderate, and high dose) in heavy drinkers (n= 23). Each subject received three doses of naltrexone in random order; each naltrexone dose was administered over an 8 day period on an inpatient unit, with a 1 week outpatient washout between doses. After stabilization at each of the naltrexone doses, subjects participated in three alcohol challenge sessions (none, moderate, and high dose) in random order; thus, each subject participated in a total of nine alcohol administration sessions. Results: Doubling the naltrexone dose (50 vs. 100 mg/day) doubled the mean serum 6-beta-naltrexol levels. At each naltrexone dose, there was a 4-fold range in 6-beta-naltrexol levels across subjects. Before alcohol administration, higher 6-beta-naltrexol levels were associated with higher ratings of sedation. After high-dose alcohol administration, higher 6-beta-naltrexol levels were associated with significantly lower ratings of liking and best effects. Conclusions: These findings provide further evidence of the involvement of the opioid system in the modulation of alcohol effects and suggest that serum 6-beta-naltrexol concentrations may be important in predicting therapeutic response to naltrexone. [source]

Trauma history characteristics and subsequent PTSD symptoms in motor vehicle accident victims,

JOURNAL OF TRAUMATIC STRESS, Issue 4 2008
Leah Irish
The present study examined the relationship between trauma history characteristics (number and type of traumas, age at first trauma, and subjective responses to prior traumas) and the development of posttraumatic stress disorder (PTSD) symptoms following a motor vehicle accident (MVA). One hundred eighty-eight adult MVA victims provided information about prior traumatization and were evaluated for PTSD symptoms 6 weeks and one year following the MVA. Results indicated that after controlling for demographics and depression, prior trauma history characteristics accounted for a small, but significant amount of the variance in PTSD symptoms. Distress from prior trauma and number of types of prior traumas were the most meaningful trauma history predictors. Results encourage further evaluation of trauma history as a multifaceted construct. [source]

Ganzfeld changes in short wavelength automated perimetry

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2002
S. Sukumar
Purpose:, The change in perception of background illumination known as Ganzfeld changes occurs while performing perimetry test. It occurs under higher background illumination and whilst covering the non-tested eye with a black patch. We investigated the occurrence of Ganzfeld changes in Short Wavelength Automated Perimetry (SWAP) and assessed the performance while covering the non-tested eye with a standard black patch and with a translucent occluder. Methods:, Twenty-eight volunteers of age 22 ± 3 years participated in the study. A custom made 16-point test was used to analyse the sensitivity with a standard black patch and with the translucent occluder. The number and duration of Ganzfeld changes in each condition were detected by subjective responses. The visual comfort of the subjects under each patching condition was assessed using a comfort scale (0,5) and subject's preference. Results:, Ganzfeld changes occurred when a standard black patch was used and appears to influence the ability to see the test targets. With a standard black patch 5 Ganzfeld changes were observed per minute and it varied between 2 and 8 s. The duration and occurrence increased towards the end of the test. Using a translucent occluder almost eliminates the occurrence of Ganzfeld changes and improved the sensitivity (p = 0.001). Of the 28 subjects, 22 preferred translucent occluder to black patch. Conclusion:, Use of a translucent spectacle occluder over the non-tested eye significantly reduces the Ganzfeld changes and improves the performance in SWAP. [source]

The ChromaGen contact lens system: colour vision test results and subjective responses

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2001
Helen A. Swarbrick
Summary The ChromaGen lens system is designed to enhance colour perception in colour vision deficiency (CVD). To investigate its efficacy, 14 CVD subjects were prescribed ChromaGen contact lenses. Colour vision tests (Ishihara, Farnsworth Munsell D-15, Farnsworth Lantern) were administered at baseline, lens dispensing, and after a 2-week lens-wearing trial during which subjective responses were recorded daily using visual analogue scales. ChromaGen lenses significantly reduced Ishihara error rates(p<0.001; ANOVA), particularly for deutan subjects. There was also a significant reduction in errors(p<0.005) on the D-15 test. Conversely, lens wear had no significant effect on Farnsworth Lantern test performance. Subjectively, subjects reported enhanced colour perception, but poor vision in dim light. Judgement of distance and motion were only slightly affected. We conclude that ChromaGen lenses may enhance subjective colour experience and assist in certain colour-related tasks, but are not indicated as an aid for CVD in occupations with colour vision-related restrictions. [source]

2141: Fitting of challenging corneas with a special design of rigid gas permeable (RGP) lens

ACTA OPHTHALMOLOGICA, Issue 2010
W ABOU SAMRA
Purpose To study the safety and efficacy of a new design of RGP lens namely Rose K irregular cornea (IC) in management of corneas with high degree of irregular astigmatism. Methods The study was made in 66 eyes of 40 patients with irregular astigmatism. The selection criterion was to obtain a sample population with irregular astigmatism that was unlikely to be corrected with spectacles or conventional contact lens. A complete ophthalmologic exploration which included topography was made. All eyes were fitted with Rose K IC after measuring precisely lens parameters according to a special trial set of this design.Refraction, visual acuity before and after fitting,maximum wearing time, contact lens related problems and patient satisfaction were analyzed. Results The studied eyes included eyes with high degree of irregular astigmatism due to keratoconus in 42 eyes (63.6%),corneal injuries in 6 eyes (9.1%), PMD in 12 eyes (18.2%), and post Lasik ectasia in 6 eyes (9.1%). After fitting of the eyes with the RGP lens, there was a significant improvement in the visual acuity (VA)in all fitted eyes. The mean VA improved from 0.16±0.25 to 0.85± 0.13(p<0.001).Study of spherical and astigmatic errors showed also a highly significant improvement. The mean spherical error was -4.6 ± 2.4 and improved to 0.50 ± 0.20 after final fitting (p<0.001). The mean astigmatic error of studied eyes was -6.2 ± 2.3 while after fitting was -0.75±0.32(p<0.001).Statistical analysis of the subjective responses indicated a strong acceptance of the lens by all subjects. Conclusion Rose K IC proved to be effective in correcting high degree of corneal astigmatism caused by a variable number of challenging corneal conditions with high visual performance and good patient comfortability. [source]

Clinical application of the multifocal visual evoked potential

CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 3 2004
David P. Crewther PhD
Background: Measures of visual function thresholds such as visual acuity and visual fields are generally dependent on subjective responses and assume maintenance of fixation, attention and motivation. In the young, elderly, cognitively impaired or malingering populations, such measures may be inaccurate or difficult to obtain. The Visual Evoked Response Imaging System (VERIS) has been claimed to give more objective topographic recordings of retinal and cortical function. This paper aims to explore the adequacy of this technique in four unusual, unrelated, clinically difficult cases. Methods: Multifocal visual evoked potentials (mfVEPs) recorded on the VERIS System 3.01 are used to assess visual function in four cases with contradictory clinical findings or unreliable subjective responses. Results: Patient 1 had sustained a head injury and had normal ocular and pupil examination but light perception in the right eye and 6/5 acuity in the left. Multifocal VEPs showed a marked depression of the right visual field with little macular response. Patient 2 had sustained a head injury, had a left field hemianopia, possible macular sparing and loss of much of the right field, reduced but variable visual acuities, good near vision and normal ocular fundi. Multifocal VEPs showed a severe depression in both visual fields (L more than R) with little macular response. Patient 3 had a left optic nerve meningioma and experienced great difficulty with visual field assessment. mfVEPs showed a bilateral depression in the superior field particularly the left field, with a larger deficit in the left eye. Patient 4 had unexplained visual acuity and peripheral field deficits. mfVEP results were inconclusive in this case. Discussion: Where there is difficulty performing traditional techniques or conflicting clinical findings, mfVEPs may provide additional objective information to aid in the assessment of patients. [source]