PubMed Health⌕ Search

Biomedical subjects

R Varma

Publications and source records attributed to R Varma.

At least 55 records · Page 3Linked to original sources
PubMed1988

Variability in digital analysis of optic disc topography.

We determined the magnitude of variability in optic disc topographical parameters on digital analysis of the optic disc using the IS 2000. The variability introduced by the system, the observer, the observer and patient, and by clinically different types of discs was assessed in the measurement of the vertical cup-to-disc ratio, horizontal cup-to-disc ratio, cup area-to-disc area, cup volume, neuroretinal rim area, and neuroretinal rim area-to-disc area. The system itself accounted for no variability. The variability introduced by one observer for the parameters ranged from 1% to 7%, and by one observer and patient from 1% to 28%. The variation among five observers ranged from 1% to 55%. Direct image acquisition (using video cameras) gave results that were no different from those obtained by digitizing the slides. Contrast-enhancement techniques did not decrease observer variability. A change in the flash intensity level at which optic disc images were acquired from 94.5 to 15.0 Watt-seconds introduced a variability of 3% to 21%. These results are less variable than those obtained on clinical observation and comparable to those of the Rodenstock image analyzer in evaluating these aspects of optic disc topography.

Adult↗
PubMed1988

Surgical therapy of chronic glaucoma in aphakia and pseudophakia.

Most glaucoma surgical procedures are less successful in aphakic or pseudophakic eyes. The authors reviewed 91 consecutive initial glaucoma procedures in aphakic patients from 1979 to 1986 to determine successful outcomes and complications. Success was defined as an intraocular pressure (IOP) of at least 30% below the preoperative value and less than 21 mmHg, less than 2 lines of Snellen acuity loss, and no further surgical intervention. At 9 months, success rates were: trabeculectomy, 4 of 15 patients; cyclodialysis, 3 of 20 patients; neodymium:YAG (Nd:YAG) cyclophotocoagulation, 1 of 8 patients; cyclocryotherapy, 9 of 22 patients; anterior chamber tube shunt (Schocket procedure), 3 of 6 patients; and argon laser trabeculoplasty, 2 of 20 patients. Severe complications included phthisis bulbi in 11% of cyclocryotherapy and severe visual loss in 20% with cyclodialysis and 14% with cyclocryotherapy. Results confirm the difficulty of surgical therapy in these patients.

Aged↗
PubMed1988

The PAR IS 2000: a new system for retinal digital image analysis.

We describe the PAR IS 2000, a new system of digital image analysis of the optic disc. The system uses a simultaneous stereoscopic camera and a video camera to acquire images directly from the optic disc and from optic disc photographs, respectively. The image data are stored on an optical laser disk capable of handling large amounts of data (4000 monochrome images/disk). These images can be analyzed using a modified digital interactive mapping program to generate stereometric parameters, contour maps, section profiles, pallor maps, depth maps, and three-dimensional topographic plots of the retina. A skeletonizing program permits determination and measurement of shifts in the position of retinal vessels. The system's wide range of capabilities may be helpful in improving patient care and ophthalmic research.

Computers↗
PubMed1987

Positional changes in the vasculature of the optic disk in glaucoma.

We analyzed 34 sets of optic disk photographs from 19 patients with glaucoma who had been followed up for ten years to evaluate changes in the position of the vasculature of the optic disks over time. Each photograph was analyzed by an image analyzer's edge-defining program for optic disk analysis and by three experienced clinicians. Image analysis of the blood vessels in 16 optic disks showed positional centrifugal shifts. The clinicians consistently noted changes in the appearance of seven optic disks. The difference between the results obtained using the image analyzer and those obtained by clinical observation was significant (P less than .05).

Adult↗
PubMed1986

Vitamin C in the human aqueous humor and cataracts.

Blood, aqueous humor and cataracts obtained from an Indian population were analyzed for ascorbic acid content. While the concentrations of ascorbic acid in the blood and cataracts were similar in patients with cortical and nuclear cataracts, the level of this nutrient was lower in the aqueous humor of patients with cortical cataracts. This suggests a sluggish transport of ascorbate from the blood to the aqueous humor in the latter group. It is possible that this lower level of ascorbate might be one of the factors participating in cataractogenesis. The lower aqueous ascorbate in the group with the cortical cataracts could not be accounted for by any dietary deficiency of this nutrient. Hence, it appears metabolically related.

Age Factors↗
PubMed1983

Beta-glucuronidase in sera of patients with epileptic seizure activity, diabetes and some other disease states.

As compared to controls and epileptics with controlled seizures, serum beta-glucuronidase enzyme is elevated significantly in epileptics with uncontrolled seizures. The enzyme begins to rise just before the seizure, remains elevated during, and for some time after the seizure and then begins to decline, unless another seizure follows the first seizure. The enzyme is not elevated in controlled diabetes patients without any secondary complications. But the enzyme is also elevated in other pathological conditions which involve increased connective tissue catabolism. However, the enzyme is elevated constantly and all the time in these conditions, in contrast with its elevation in uncontrolled epilepsy only close to the seizures.

Brain↗
PubMed1983

Serum glycoconjugates in children with schizophrenia and conduct and adjustment disorders.

The serum glycoproteins represented by the individual protein-bound carbohydrate components and glycosaminoglycans represented by the hexuronic acid contents were determined in the sera of black and Caucasian normal children and children with diagnoses of schizophrenia, conduct disorder, and adjustment disorder. There were no race-related or sex-related differences in glycoproteins and glycosaminoglycans in the sera of normal children. Although the serum glycosaminogltents were determined in the sera of black and Caucasian normal children and children with diagnoses of schizophrenia, conduct disorder, and adjustment disorder. There were no race-related or sex-related differences in glycoproteins and glycosaminoglycans in the sera of normal children. Although the serum glycosaminogltents were determined in the sera of black and Caucasian normal children and children with diagnoses of schizophrenia, conduct disorder, and adjustment disorder. There were no race-related or sex-related differences in glycoproteins and glycosaminoglycans in the sera of normal children. Although the serum glycosaminoglycans were significantly elevated in children with a diagnosis of schizophrenia, the levels were in normal range in children with conduct and adjustment disorders. All of the protein-bound carbohydrates were elevated in schizophrenic children. However, only arabinose and galactosamine were significantly elevated in children with a diagnosis of conduct disorder, while only galactosamine was elevated in children with adjustment disorder. The presence of arabinose in serum glycoprotein was confirmed by chemical ionization-mass spectrometry. The possible causes of the differential elevation of the glycoconjugates in psychiatric disorders in relation to the effect of stress and environment are discussed.

Adjustment Disorders↗
PubMed1983

The protein-bound carbohydrates of seromucoid from normal human serum.

The neutral sugars and hexosamines in the seromucoid fraction of normal human serum were identified and determined simultaneously by gas-liquid chromatography of their aldononitrile acetates. Besides the sialic acid, normal seromucoid contained fucose, arabinose, mannose, glucose, galactose, glucosamine and galactosamine. The presence of arabinose and glucose, not previously reported in seromucoid, as well as the other known carbohydrate components determined by GLC were confirmed from their fragmentation patterns in the electron impact mass spectra and chemical ionization spectra.

Adult↗