Psychophysical characterisation of early functional loss in glaucoma and ocular hypertension.

AIM: The psychophysical evaluation of selective cell loss in early glaucoma and ocular hypertension. METHODS: Contrast sensitivity was measured for the detection of luminance modulated gratings at a range of spatial (0.5, 2, 8 c/deg) and temporal (0, 16 Hz) frequency combinations in three groups of age matched patients (primary open angle glaucoma, ocular hypertension, normal controls; n=16). Stimuli of 5 degrees were presented foveally and at 15 degrees along the nasal horizontal meridian under photopic conditions. RESULTS: Fovea: Compared to the normal group, the thresholds for the glaucoma patients were significantly elevated at all spatial and temporal frequencies (p<0.0001), but this reduction was not significantly different at any particular spatial or temporal frequency (p>0.1). There was no difference in contrast sensitivity between the normals and OHTs (p>0.10). Periphery: The thresholds of the glaucoma patients were elevated compared to the normal controls (p<0.01). The loss of sensitivity was slightly greater at the higher spatial frequencies for both stationary and flickering patterns but this did not reach significance (p=0.09). The contrast sensitivity in normal and OHT groups was not significantly different (p>0.10). CONCLUSIONS: In early glaucoma, the reduction in contrast sensitivity to stimuli which isolate the magnocellular pathway (0.5 c/deg, 16 Hz) was not significantly different compared with the reduction in contrast sensitivity to stimuli that isolate the parvocellular pathway. These findings are not consistent with the hypothesis that the magnocellular pathway is selectively damaged in early glaucoma.

A comparative study to assess the clinical use of Fluorescein Meniscus Time (FMT) with Tear Break up Time (TBUT) and Schirmer's tests (ST) in the diagnosis of dry eyes.

INTRODUCTION: The clinical diagnosis of dry-eye is confirmed by a suitable test of tear production and the technique commonly used today to diagnose dry eye is the Schirmer's test (ST). Although the ST is easy to perform it gives variable results, poor reproducibility and low sensitivity for detecting dry eyes. Another test, the tear break up time (TBUT) is used to assess the stability of tears which if abnormal may also cause symptomatic dry-eye. We present the results of both these tests and a new test, which shows greater sensitivity than the ST in detecting aqueous tear deficiency. The fluorescein meniscus time (FMT) is a new test developed in conjunction with one of the authors (CL) and the Department of Ophthalmology at the University Hospital of Wales. The FMT is a measure of the rate at which a fluorescent tear meniscus is formed using 2% sodium fluorescein, a stopwatch and suitable illumination with a slit lamp. METHOD: An open controlled study in 62 patients and 51 controls was conducted to compare the ability of ST, FMT and TBUT to detect dry-eye in a group of patients diagnosed with rheumatoid arthritis and symptomatic dry eyes for a minimum period of 6 months. A separate control group of 15 subjects was tested on three separate occasions to assess the reproducibility of the FMT test. RESULTS: All three tests showed a statistically significant difference between the patient and control populations; Mann-Whitney P < 0.001. There was a correlation between the right and left eye for all three tests in the control group (ST r(2) = 0.77, FMT r(2) = 0.98, TBUT r(2) = 0.94). This correlation was markedly reduced for FMT and TBUT in the patient population and was in keeping with the symptoms reported as being worse on one side in a proportion of the patients (FMT r(2) = 0.52, TBUT r(2) = 0.54, ST r(2) = 0.75). A correlation with age was also observed for all the three tests in the control group (ST r(2) = 0.74, FMT r(2)= 0.92, TBUT r(2) = 0.51), but not in the patient population (ST r(2) = 0.06, FMT r(2) = 0.18, TBUT r(2) = 0.03). A significant correlation was observed between the ST and FMT in both the control (ST vs FMT r(2) = 0.65) and patient population (ST vs FMT r(2) = 0.44). There was no value greater than 200 seconds for FMT recorded in the control group. Using this value to define an abnormal FMT, 85% of the patients (72% of the eyes tested) had an abnormal result. This was in contrast to 35% of patients (26% of the eyes tested) with abnormal results detected by ST. Using ANOVA and Student's paired t-test, there were no significant differences between the three sets of values recorded serially over 3 months to assess the reproducibility of the FMT. The average standard error of the mean was 2.72% and the average co-efficient of variation 4.07%. CONCLUSION: Our study suggests that the FMT is a more sensitive test with good reproducibility compared to the Schirmer's test. The FMT correlates with the ST and suggests that both tests measure aqueous tear deficiency. The FMT therefore is a better alternative to ST currently being used to test aqueous tear deficiency.

Glaucoma: squaring the psychophysics and neurobiology.

Advances in our understanding of the pathophysiology of retinal ganglion cell death in glaucoma are providing important insights into the functional changes occurring in retinal ganglion cells in the early stages of the disease. These exciting new findings may help us develop psychophysical tests to monitor early retinal ganglion cell damage, possibly before neurons are committed to the process of cell death.

Ocular signs and symptoms and vitamin A status in patients with cystic fibrosis treated with daily vitamin A supplements.

BACKGROUND/AIMS: Patients with cystic fibrosis (CF) may have low plasma vitamin A levels from malabsorption, zinc deficiency, liver disease, or poor compliance with prescribed supplements. In view of the increasing number of adults with CF, many of whom drive cars, it is important to assess vitamin A status. In our centre an attempt has been made to achieve normal levels of fat soluble vitamins by annual estimation of plasma levels and appropriate oral supplementation. This study aimed to determine if this approach prevents vitamin A deficiency and the consequent problems with dark adaptation. METHODS: The study was conducted at the regional adult and paediatric cystic fibrosis unit and the patients were recruited from there. Dark adaptation studies were conducted at the department of ophthalmology, St James's University Hospital. All patients are regularly seen in the outpatient department by a CF specialist dietitian and have a comprehensive annual dietary assessment. 28 patients had the following investigations: serum retinol, plasma zinc, serum retinol binding protein, liver function tests, dark adaptation, contrast sensitivity, and anterior ocular surface status. 25 age and sex matched controls without CF or ocular pathology were also recruited for the dark adaptation study. RESULTS: None of the patients had vitamin A deficiency, the median value of serum retinol being 48 microg/dl, range 31-80 microg/dl (normal range 30-80 microg/dl). Dark adaptation was normal in all cases compared with the control group where the mean value was 3.4 log units of threshold luminance (95% confidence interval 2.4-4.0). None of the test group had a value of threshold luminance 2 SD above the mean value for the control group. Eight patients had reduced contrast sensitivity. The median value for serum zinc was 14.2 micromol/ l, range 13-81 micromol/l (normal range 8-23 micromol/l) and the median value for retinol binding protein was 36 mg/l, range 13-81 mg/l (normal range 35-58 mg/l). There was no correlation between dark adaptation and serum retinol, zinc, or retinol binding protein. Two patients had clinical evidence of dry eye. CONCLUSION: Regular estimates of plasma vitamin A together with appropriate supplementation and expert dietetic review can maintain normal dark adaptation in patients with cystic fibrosis. The occurrence of reduced contrast sensitivity function is well documented but remains an unexplained phenomenon and deserves further study.

Ocular injury with xylene--a report of two cases.

Xylene is a hydrocarbon solvent found in various industrial preparations such as paint and is widely used in pathology laboratories. When inadvertently instilled into the eye significant ocular injury can occur with the potential for blindness. Such injuries to the ocular surface resemble those due to alkali. Ocular surface injury due to xylene has not been reported previously in the literature. We strongly recommend that these injuries be treated as emergencies in a similar way to alkali burns in the Eye department since the chemical mixture of which xylene forms a part may be alkaline. Such an approach is vital in order to save sight.

Corneal perforation and decompensation after automated lamellar keratoplasty for hyperopia.

We describe a case of corneal perforation and decompensation after automated lamellar keratoplasty (ALK) in a middle-aged hyperopic man who had had unsuccessful holmium laser thermokeratoplasty. The corneal decompensation responded to gluing and application of a bandage contact lens but despite treatment, the corneal flap remained precariously poised with a localized area of thinning that is predisposed to future perforation and decompensation. This case highlights the potential for serious complications and subsequent visual morbidity after ALK.

Psychiatric disorders in two general hospitals: a survey of prevalence and treatment by nonpsychiatrist physicians.

This study reports an opinion survey of 211 nonpsychiatrist physicians in two general hospitals who estimated that 16.1% of their patients have psychiatric disorders and that they spent 13.8% of their time in treating the psychiatric components of their patients' illnesses. Physicians indicated that anxiety and psychosomatic and depressive illness were the most frequent psychiatric disorders and that one-third of them would personally treat such disorders without referral to psychiatric consultation. The findings also suggest that adequate undergraduate psychiatric education was associated with increased recognition of psychiatric disorders and more preference for their personal treatment. In addition, it provides a possible explanation for the discrepancy between the high prevalence of psychiatric disorders in general hospital patients and the low referral rate to psychiatric consultation.

Patterns of psychiatric consultations in Kuwait general hospitals.

Two hundred and nineteen consecutive referrals to psychiatric consultation services from all general hospitals in Kuwait over a 3-month period were studied and compared with a control group of 100 patients who were not referred for psychiatric consultation. The two groups differed significantly in age, sex, marital status, employment, and past psychiatric treatment. Inpatients were more often referred than outpatients with an overall low referral rate of 0.3%. The department of general medicine referred 74.4% of patients in contrast to 11.4% referred by the department of general surgery. The most common reason for referral was for assessment of a suicide attempt in the inpatient group, and the absence of organic cause for patients' physical symptoms in the outpatient group. Acute situational disturbance that resulted in a suicide attempt was the most common psychiatric diagnosis (26%), followed by depressive illness (19.5%) and organic psychotic disorders (8.2%). Our findings are similar to those reported in the literature, and the present study suggests a national underutilization of psychiatric consultation services in general hospitals.

Screening for alcoholism among alcohol users in a traditional Arab Muslim society.

The Short Michigan Alcoholism Screening Test (S-MAST) was applied to 140 alcohol users in the traditional Muslim society of Kuwait. One hundred were confirmed alcoholics and 40 were self-disclosed social drinkers in the community. The questionnaire significantly discriminated between the groups. Its sensitivity level was 100% and its specificity 82.5%. Although all except one of the S-MAST items elicited significant differences between the groups in question, it appears that the particular sociocultural conditions of the setting may influence the validity of some of them.

Schizophrenia in ICD-10: a field trial of suggested diagnostic guidelines.

A tenth version of the International Classification of Diseases (ICD-10) is currently being prepared by the World Health Organization, who called for field trials of suggested guidelines. A field trial of the guidelines for the diagnosis of schizophrenia is presented. There is a consistency with ICD-9-based diagnosis. Schneider's First-Rank Symptoms (FRS) acquire special importance in the suggested guidelines, but caution is necessary in detecting these symptoms in cultures in which socioculturally shared beliefs bear a resemblance to FRS.

Prospective study of alcoholism treatment in Kuwait: a 5-year follow-up report.

The outcome of a 5-year prospective follow-up study of 100 patients treated in the Kuwait Hospital for alcohol-related problems is reported using two parameters computed from weighted follow-up variables, i.e., Offset Score measuring patients' initial follow-up status and Direction of Slope summarizing consequent follow-up scores. Nineteen patients had died representing 14 times the age-corrected national rate. Univariate and multivariate analyses of outcome measures against prefollow-up patients' characteristics revealed that variables indicating heavy alcohol use independent of each other predicted negative outcome and mortality. The tendency of the group score distribution towards normalization uninfluenced by treatment is demonstrated. The pertinence of these findings to the medical profession in Kuwait is stressed.