Biomedical subjects

R C Ramsay

Publications and source records attributed to R C Ramsay.

29 records · Page 2Linked to original sources

PubMed1980

Histocompatibility antigen frequencies in diabetic retinopathy.

We studied the histocompatibility antigens A and B in 300 insulin-dependent diabetics: 200 had proliferative retinopathy and 100 did not. The two groups were matched for known duration of diabetes and other clinical features. In both groups the frequencies of HLA-B8, HLA-B18, and HLA-B8/HLA-B15 were significantly higher, and those of HLA-B7 and HLA-B12 were significantly lower than in healthy controls. The patients with proliferative retinopathy were significantly less often positive for HLA-B7 (X2 = 10.0; Pc < .03) than patients with nonproliferative retinopathy. When both groups were stratified for age at diagnosis, there were additional differences. HLA-B15 was significantly more frequent in the proliferative retinopathy group with age at diagnosis between 15 and 40 years (nonproliferative retinopathy = 16.4%; proliferative retinopathy = 39.4%; X2 = 7.89, Pc < .03; relative risk = 3.32) and HLA-B7 significantly less frequent (nonproliferative retinopathy = 23.6%; proliferative retinopathy = 5.6%; X2 = 8.0, Pc < .03; relative risk = 0.19). These differences in histocompatibility frequencies between patients with and without proliferative retinopathy indicate a genetic contribution to diabetic retinopathy.

Adolescent↗

PubMed1979

The visual status of diabetic patients after renal transplantation.

To determine the effect of renal transplantation on visual status, we studied 134 eyes of 67 diabetic patients prospectively for one to seven years, with a mean of three years, after surgery. The best-corrected visual acuity and retinopathy status were determined at the time of surgery and annually thereafter. Useful visual acuity (greater than or equal to 6/15 [20/5o]) was present in 49% (66) of the eyes at the time of the baseline examination and in 51% (69) at the final determination. Of the 134 eyes 40% (54) were legally blind (less than or equal to 6/60 [20/200]) before surgery. Sixty-eight percent (91) of the eyes showed no significant visual change during the period of follow-up, 15% (20) showed significant improvement, and 17% (23) deteriorated significantly after surgery. With regard to the retinovitreous findings, 13% (12) of the eyes had non-proliferative retinopathy, 20% (26 had active proliferative retinopathy, and 67% (90) had inactive or involutional retinopathy. The results of this study showed stable or improved visual function in 83% (111) of the eyes after renal transplantation. Transplantation before dialysis becomes necessary may ben an important consideration in an attempt to reduce the high incidence of visual impairment in diabetic patients with renal failure.

Adult↗

PubMed1979

Retinal astrocytoma.

A 41-year-old man had a 6 x 6 x 5-disk diameter amelanotic tumor in the posterior fundus. The clinical and fluorescein angiographic appearance suggested a benign retinal vascular tumor, although amelanotic choroidal melanoma and retinoblastoma were diagnostic possibilities. An incisional 48-hour radioactive phosphorus (32P) uptake test was performed and the result showed an increased uptake over the tumor mass of 100% as compared to the control quadrants. The globe was enucleated and the pathologic diagnosis was isolated astrocytic glioma of the retina with minimal, if any, malignant potential. The highly developed vascular system of the tumor probably contributed to the false-positive test result.

Adult↗

PubMed1979

Ten year experience with renal transplantation in juvenile onset diabetics.

Between 1968 and 1978, 305 juvenile onset diabetic patients with uremia and 462 nondiabetic uremic patients of similar age received primary renal allografts at the University of Minnesota. Two hundred eight of the diabetic patients are alive and 190 have functioning renal grafts three months to ten years after transplantation. Cumulative patient survival rates at two years for diabetic recipients of kidneys from HLA identical siblings, other related and cadaver donors are 90, 73 and 68%, respectively, the corresponding graft functional survival rates are 90, 67 and 55%. For nondiabetic patients receiving kidneys from the same donor categories the corresponding patient survival rates are 97, 86 and 75%, while the graft functional survival rates are 94, 77 and 64%. The differences in patient and graft survival between diabetic and nondiabetic recipients are statistically significant only for the patients receiving grafts from HLA-nonidentical related donors. For all recipients under the age of 30, there are no statistically significant differences in patient and graft survival. Regardless of the age of the patient or the source of the kidney, the survival of diabetic patients treated with transplantation at our institution is better than the use of chronic hemodialysis, alone. Technical complications do not occur more frequently in diabetic transplant recipients. Cardiovascular disease is responsible for most of the late deaths in these diabetic patients. Amputations of digits or extremities have been required in 15% of the diabetic patients. On the positive side, the vision of 88% of these recipients remained stable or had improved visual acuity, and 82% of the diabetic patients were actively rehabilitated after transplantation. Kidney transplantation is the treatment of choice for end-stage renal failure in diabetic patients, just as it is for most uremic patients.

Adult↗

PubMed1978

Ocular perforation following retrobulbar anesthesia for retinal detachment surgery.

We encountered three examples of the perforation of the globe by the retrobulbar needle in a series of 4,000 patients who had undergone retinal reattachment surgery with local anesthesia. The presence of significant myopia was a contributing factor in all three cases. We managed the perforation site through the detached retina with cryopexy and external tamponade, and we treated perforations through the attached retinas either with cryopexy at surgery or photocoagulation postoperatively.

Adult↗

PubMed1978

Ipsilateral subclavian to external carotid and STA-MCA bypasses for retinal ischemia.

The surgical treatment of a patient with retinal ischemia in the left eye and occlusion of the left common and internal carotid and right internal carotid arteries is presented. After demonstration of filling of the left external carotid artery from vertebral collaterals, as saphenous vein graft from the left subclavian to the left external carotid artery was performed prior to a left superficial temporal artery to middle cerebral artery bypass. This case demonstrates the feasibility of revascularization in the presence of occlusion of the ipsilateral common and internal carotid arteries.

Blindness↗

PubMed1977

Involutional diabetic retinopathy.

The end-stage or involutional phase of proliferative diabetic retinopathy may result in stabilization of vision for long periods of time. However, the clinical resemblance to the progressive tapetoretinal degenerations suggests that marked functional impairment of the retina is present in such eyes. We studied 19 eyes with involutional retinopathy to document the status of the retinal function. Studies included fluorescein angiography, visual field examination, dark adaptation testing, color vision testing, electro-oculography and electroretinography (ERG). The results indicated marked functional abnormalities in all eyes. The ERG tracings showed uniformly subnormal responses and delayed implicit times, similar to those of dominantly inherited retinal pigment degeneration, and indicative of a progressive retinal disorder. In two patients, color vision testing showed defects similar to those seen in inherited tritanopia; and in the remaining patients, defects were indicative of an acquired blue-yellow dyschomatopsia.

Adaptation, Ocular↗

PubMed1973