Kay Ellen Frank

Glycation of Skin Collagen in Type I Diabetes Mellitus: Correlation With Long-Term Complications

Nonenzymatic glycosylation (glycation) of collagen was measured by boronate affinity chromatography in skin biopsies from 41 type I diabetics with mean duration of diabetes of 25 yr (range 20–40 yr) and from 25 age-matched controls. Mean level of Amadori products was significantly increased in diabetic [7.85 ± 1.78 (SD) nmol/mg collagen] versus control subjects [3.34 ± 1.06 (SD) nmol/mg collagen, P < .001] but did not correlate with age, diabetes duration, or severity of retinopathy, nephropathy, arterial stiffness, and joint stiffness. Similarly, mean collagen content per biopsies was 42% increased in diabetic versus control subjects (P < .001) but did not correlate with age, diabetes duration, or severity of complications. A weak but positive correlation between glycohemoglobin level and glycation of skin collagen was observed. These results indicate that Amadori products cannot explain by themselves the pathogenesis of diabetic complications unless individual tissue response to glycation is different in subjects with and without complication. They do not exclude a role for the late stages of the Maillard reaction, nonenzymatic browning, in the formation of some of these complications.

Age-related normalization of the browning rate of collagen in diabetic subjects without retinopathy.

The age-related changes in collagen-linked fluorescence (browning) were investigated in skin from subjects with long-standing type I diabetes. Overall browning rates were 2.4 times higher in diabetics than in controls (P less than 0.02) and slope intercept accurately reflected the mean age of onset of diabetes (11.6 vs. 11.2 yr), suggesting that the browning process has the attributes of a biological clock. Browning rates were not different in controls and diabetics without retinopathy (P greater than 0.05) but were 2.4 (P less than 0.05) and 2.7 (P less than 0.01) times increased in the presence of background and proliferative retinopathy, respectively. Compared with subjects with retinopathy, individual browning rates since onset of diabetes decreased with advancing age in subjects free of retinopathy (P less than 0.001). Extrapolation revealed that they would become identical to that of nondiabetic subjects by the age of 66.4 yr. These results suggest the presence of a mechanism that controls the browning rate of collagen in diabetics who do not develop retinopathy.

Subretinal Neovascularization Following Rubella Retinopathy

A 17-year-old girl and an 11-year-old girl with rubella retinopathy had decreased vision in one eye secondary to subretinal neovascularization and hemorrhage. In both cases a disciform scar with permanent decrease in central vision resulted.

Quantitative Vitreous Fluorophotometry in Insulin-treated Cystic Fibrosis Patients

A series of 22 patients with cystic fibrosis (CF) of similar clinical severity (9 with normal carbohydrate tolerance and 13 with insulin-treated fasting hyperglycemia) was examined with quantitative vitreous fluorophotometry. All of the CF patients studied had normal fundi on ophthalmoscopy, fundus photographs, and fluorescein angiography. Mean vitreous fluorescein concentration in the CF patients whose hyperglycemia was treated with insulin (11.79 ng/ml) was significantly higher than in CF patients with normal carbohydrate tolerance (6.98 ng/ml, P < 0.005). Thus, CF patients with fasting hyperglycemia demonstrate a breakdown of the bloodretinal barrier. When CF patients with fasting hyperglycemia were compared with age- and sex-matched type I diabetics, there was no significant difference in mean vitreous fluorescein accumulation. Thus, breakdown of the blood-retinal barrier, one of the earliest detectable functional abnormalities that may be associated with the microangiopathy of diabetes mellitus, also occurs with equal frequency and severity in the diabetes secondary to pancreatic fibrosis associated with CF.

Relative Frequency of Ultrasound Diagnoses in Patients Referred for Ophthalmic Ultrasound

An ultrasound diagnostic coding system was developed that permitted entry of diagnoses into a programmable calculator, thus permitting rapid information retrieval of patients with a specific diagnosis or diagnoses as well as the number of patients with a specific diagnosis. Cataract, vitreous opacity, trauma, choroidal disease, and retinal detachment were the most common diagnoses made. Only 7.2% of the patients had a normal ultrasound, indicating that ultrasound examination is a test probably underutilized by ophthalmologists.

Ultrasonic Findings in Diabetic Vitreoretinopathy

The purpose of this study is to demonstrate by serial ultrasonography the course of the vitreoretinal disease of diabetes, to determine what information may be obtained from ultrasonic evaluation and whether ultrasonic examination can predict remissions or exacerbations. The ultimate goals are to evaluate ultrasonography as a method for determining the advisability of vitrectomy in these eyes and to determine the role of ultrasound in the planning and execution of the vitrectomy procedure.

Posterior Ocular Curvature by B Scan Ultrasonography

Analysis of the posterior curvature of the eye on B sector scan ultrasonography is an important parameter in the evaluation of normal and abnormal ocular conditions. In the normal eye, as sound waves pass through the crystalline lens they are refracted producing a well known artifactual change in its posterior curvature making it appear more concave and anteriorly displaced. The magnitude of this refractive effect is greatest as the distance from the crystalline lens increases and thus it is best studied in myopic eyes in which the axial length is greater.