Monique S. Roy

The ovine corticotropin-releasing hormone-stimulation test in type I diabetic patients and controls : suggestion of mild chronic hypercortisolism

We examined hypothalamic-pituitary-adrenal (HPA) axis function in insulin-dependent diabetic outpatients (N = 22) and age-, sex-, and weight-matched normal controls (N = 22). The evaluation included measurements of 9:00 AM fasting plasma cortisol and cortisol-binding globulin (CBG) levels, 24-hour urinary free cortisol (UFC) excretion, and plasma corticotropin and cortisol responses to intravenously administered ovine corticotropin-releasing hormone ([CRH] 1 microgram/kg given as a bolus at 8:00 PM). Diabetic patients had significantly elevated 9:00 AM plasma cortisol levels (mean +/- SE, 300.7 +/- 99.3 v 237.3 +/- 99.3 nmol/L, P < .04), higher 24-hour UFC excretion (313.2 +/- 112.6 v 244.2 +/- 69.3 nmol/24 h, P < .02), and greater cortisol responses to CRH infusion (time-integrated values: 49,408.2 +/- 11,289.8 v 40,217.9 +/- 7,228.6 nmol/L.120 min, P < .004; peak cortisol values: 529.7 +/- 107.6 v 438.7 +/- 77.3 nmol/L, P < .002) than controls. UFC excretion values were positively correlated with both 5-year averaged hemoglobin A1c level (P = .03) and total number of insulin units administered per day (P = .03). These results suggest that insulin-dependent diabetic outpatients have mild chronic hypercortisolism, which might influence the control of the disease and play a role in the development of its chronic complications.

Second eye involvement in age-related macular degeneration: A four-year prospective study

Age-related macular degeneration (AMD) usually affects both eyes over time. Among patients with advanced AMD in one eye estimates of the risk to the second eye have been diversely reported. Therefore we examined, over a four year period, the rate of second eye involvement in 41 patients with either exudative or advanced atrophic AMD in one eye, and early macular changes in the second eye with best corrected vision of 20/30 or better. The cumulative risk of developing either exudative AMD or atrophic AMD and 20/80 or less vision in the second eye was 23% at four years. The cumulative risk of losing 10 or more letters on the ETDRS visual acuity chart in the second eye was 35% at four years. These results are discussed in relation to previously reported rates of second eye involvement in AMD.

Color vision and age in a normal North American population

Color vision is known to change with age. We conducted the Farnsworth-Munsell (FM) 100-Hue and the Lanthony Desaturated Panel D-15 (DD-15) tests in 115 normal North American subjects aged 5–81 years to obtain age-specific norms for these procedures. For each test, color discrimination was best between the ages of 20 and 50 years. Both increasing age and the occurrence of lens changes were significantly associated with increasing 100-Hue error scores. Age-specific norms for the 100-Hue test were comparable with those obtained by Verriest in a European population, but such norms for the DD-15 test are problematic. Our data indicate somewhat greater variability in the DD-15 than in the 100-Hue test.

Retinal leakage in retinal vein occlusion: reduction after hyperbaric oxygen.

A 54-year-old woman with a history of bilateral central retinal vein occlusion, probably due to an inflammatory process, developed a hemispheric retinal vein occlusion with cystoid macular edema in her only seeing eye. Five months later, in the absence of improvement in vision and macular edema, she received on two occasions a 2-weekly course of twice daily 100% hyperbaric oxygen. After each course retinal leakage, as assessed by vitreous fluorophotometry, decreased from abnormal to the normal range while visual acuity improved by two lines. The possible implications are discussed.

Excess of depressive symptoms and life events among diabetics

We compared a group of insulin-dependent diabetic outpatients with normal control subjects for their scores on the Beck Depression Inventory (BDI) and for their experience of recent life events. Diabetic patients had significantly higher BDI scores than controls and had experienced significantly more life events during the previous 6 months. These results suggest that psychiatric symptoms and social problems are common among insulin-dependent diabetics. Longitudinal studies of psychiatric disorder among diabetic patients appear to be indicated.

Dysregulation of the hypothalamo-pituitary-adrenal axis and duration of diabetes

We compared insulin-dependent diabetic outpatients with and without retinopathy for plasma indices of hypothalamo-pituitary-adrenal (HPA) axis activity. Diabetic patients with moderate-to-severe retinopathy had significantly higher postdexamethasone plasma levels of adrenocorticotropic hormone than patients with minimal or no retinopathy. However, when duration of diabetes was taken into account this difference was no longer significant. These data suggest that dysregulation of the HPA axis and retinal microvascular complications found in diabetic patients may both be a function of duration of diabetes.

Vision Loss without Amsler Grid Abnormalities in Macular Subretinal Neovascularization

An 87-year-old woman, with known atrophic senile macular degeneration in one eye, had isolated decreased reading ability while Amsler grid testing was normal. This led to the early diagnosis of macular subretinal neovascularization in the other eye. Thus patients at high risk for neovascular macular degeneration should be made aware of possible subtle changes in vision as well as abnormalities in the Amsler grid. Regular visual acuity check and careful biomicroscopic examination of the macula should be part of each follow-up examination.

Saturation Discrimination and the Degree of Diabetic Retinopathy

A blue-yellow deficiency is generally observed when color vision is altered secondary to diabetes. What is not clear, however, is the relationship between the degree of retinopathy and the degree of color deficiency. We have measured spectral saturation discrimination (from 430–680 nm) in normal and diabetic subjects as the first perceptible step from a white reference field (x = 0.45, y = 0.43). We used an optical system which permitted the patient to vary colorimetric purity (at constant luminance) by adjusting a single control knob. Constancy of luminance was assured by preliminary measurement of each patient’s relative luminosity function. All diabetic subjects had normal visual acuity. Diabetic patients without retinopathy showed normal saturation discrimination functions. However, in patients with retinopathy, there was little correlation between losses in saturation discrimination and the degree of retinopathy. That is, a patient having minimal retinopathy, can manifest the same loss in saturation discrimination as a patient having severe background retinopathy.

Lanthony desaturated panel D15 test in sickle cell patients

The Lanthony D15 desaturated test was used to compare color vision in sickle cell patients with 20/20 visual acuity and peripheral lesions of sickle cell retinopathy with normal controls. Sickle cell patients had significantly higher Lanthony error scores and significantly more blue-yellow and mixed color vision defects than controls. Among patients with sickle cell anemia (SS), Lanthony and Farnsworth Munsell 100 Hue test scores were significantly correlated, and both tests showed good agreement in identifying the presence or absence of a color defect. These results suggest that the Lanthony D15 test may be a useful clinical tool to identify blue-yellow color defects, especially because of its brevity and simplicity of administration.

Retroequatorial red retinal lesions in sickle cell anemia

We report 2 patients with sickle cell anemia who showed retroequatorial localized red retinal lesions. In 1 patient these lesions were associated with closure of the retinal precapillary arteriole and capillary bed. In both patients these lesions receded during the course of therapy with a selective arteriolar vasodilator, nifedipine. These observations are discussed in relation to the possible pathogenesis of the retinopathy seen in patients with sickle cell anemia.