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S A Arshinoff

Publications and source records attributed to S A Arshinoff.

15 recordsLinked to original sources
PubMed1999

Phaco slice and separate.

Phaco slice and separate retains the advantages of the chopping techniques of Nagahara, Koch, and Fukasaku but replaces chopping or snapping with slicing across the center of the phaco-tip-stabilized nucleus using a Nagahara chopper and then repositioning the chopper to optimally separate the divided lens halves. As the lens is rotated in the capsular bag, small pieces of the nuclear pie are sliced off, separated, emulsified, and aspirated. Emulsification and aspiration can alternatively be left until most or all the slices have been made. This technique works with a broader range of lens densities than other chopping techniques and uses no sculpting and very little phaco time. The phaco time required for this technique is relatively independent of nuclear density compared with a sculpting technique.

Capsulorhexis↗
PubMed1999

Dispersive-cohesive viscoelastic soft shell technique.

Based on their physical properties, ophthalmic viscoelastic agents can be divided into 2 groups: higher-viscosity cohesive and lower-viscosity dispersive. Higher-viscosity cohesive agents are best at creating and preserving space, while lower-viscosity dispersive agents are retained better in the anterior chamber and are capable of partitioning spaces. The viscoelastic soft shell technique maximizes the advantages and minimizes the disadvantages of both groups by using dispersive and cohesive agents together in sequence based on the desired surgical goal.

Anterior Chamber↗
PubMed1998

New method to measure the retention of viscoelastic agents on a rabbit corneal endothelial cell line after irrigation and aspiration.

PURPOSE: To quantify the surface retention of several ophthalmic viscoelastic agents following irrigation and aspiration (I/A) using a new in vitro method. SETTING: Alcon Laboratories, Inc., Fort Worth, Texas, USA. METHODS: A rabbit corneal endothelial cell line was cultured to confluency in 24-well plates, and the cells were labeled quantitatively with internalized neutral red dye. Five ophthalmic viscoelastic agents were applied to cover the monolayer of cells: sodium hyaluronate (Healon, Provisc, and Amvisc Plus), Formulation A (a dispersive, nonproteinaceous, synthetic polymer), and sodium chondroitin sulfate, sodium hyaluronate (Viscoat). Irrigation and aspiration (with fluid turbulence similar to that encountered in phacoemulsification surgery) were performed on each well for 3 minutes, using 120 mL of balanced salt solution with bicarbonate. dextrose, and glutathione (BSS Plus). The cells were treated with an acidified ethanol solution to extract the dye from the cells left without a viscoelastic cover. The extracted dye was measured by spectrophotometry and compared with the total dye recovered from control cells. RESULTS: The retention value, which represented the percentage of cells with viscoelastic retained on the surface, was calculated as follows: Healon, 7; Provisc, 16; Amvisc Plus, 17; Formulation A, 55; Viscoat, 90. On a nonadsorptive, non-cell surface, the retention values of the five viscoelastics were significantly less than those on cells. CONCLUSION: The results of this experimental model suggest that cohesive viscoelastics are readily removed from the cells, while dispersive viscoelastics are highly retained. In addition, mutual surface interaction (electrical charge and other properties) plays a significant role in determining the retention of viscoelastics on the corneal endothelial cell surface following I/A.

Animals↗
PubMed1998

Quantitative method to determine the cohesion of viscoelastic agents by dynamic aspiration.

PURPOSE: To quantitatively determine the cohesion of ophthalmic viscoelastic agents using an in vitro method based on dynamic aspiration kinetics. SETTING: Alcon Laboratories, Inc., Fort Worth, Texas, USA. METHOD: Five viscoelastic agents were tested: Healon GV (sodium hyaluronate 1.4%); Provisc (sodium hyaluronate 1.0%); Healon (sodium hyaluronate 1.0%); Amvisc Plus (sodium hyaluronate 1.6%); Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%). Samples were placed into a tared polypropylene container using a positive displacement pipette. Calibrated vacuum was applied for 2 seconds to a polypropylene tip (inner diameter 0.5 mm) lowered into the viscoelastic sample. The quantity of viscoelastic agent remaining in the container after aspiration was determined gravimetrically. The procedure was repeated at various vacuum levels between 100 and 700 mm Hg. The percentage of viscoelastic agent aspirated was plotted against vacuum pressure. The slopes of these curves indicate the relative cohesion of the viscoelastic sample. RESULTS: The cohesion-dispersion indices (percentage viscoelastic agent aspirated/100 mm Hg) were Healon GV (72.3) > Provisc (46.0) > Healon (31.2) = Amvisc Plus (21.4) > Viscoat (3.4). CONCLUSION: The method provided a quantitative basis for the clinical classification of viscoelastic materials as cohesive or dispersive. The aspiration kinetics profile (curve shape), maximum rate of removal, and vacuum levels at which the bolus removal of the viscoelastic agent started (break point) were useful in characterizing the viscoelastic agents. Because the results agree with the clinical impression of cohesion/dispersion, this method may be used to predict the surgical performance of viscoelastic agents.

Adhesiveness↗
PubMed1998

Prospective, randomized trial comparing Micro Visc Plus and Healon GV in routine phacoemulsification.

PURPOSE: To compare the safety and efficacy of two sodium hyaluronate viscoelastics--MicroVisc Plus and Healon GV--in routine phacoemulsification and evaluate whether these more viscous and cohesive agents offer benefits compared to viscoelastics of standard viscosity and cohesion. SETTING: York Finch Eye Associates and York Finch General Hospital, Toronto, Canada. METHODS: An unmasked, randomized, prospective clinical trial of 100 eyes of 100 patients having routine phacoemulsification with intraocular lens implantation was conducted comparing the safety and efficacy of MicroVisc Plus with those of Healon GV. Preoperative and 6 hour, 1 and 5 days, and 1 and 6 month postoperative assessments included acuity, corneal thickness, intraocular pressure, and surgeon assessment of the task-facilitating efficacy of the viscoelastics. Results were compared with those of a similar trial of MicroVisc and Healon. RESULTS: There were no statistically significant differences between the two treatment groups at any follow-up. The surgeon judged the two viscoelastics to be equivalent, although somewhat different in facilitating surgery. There was significantly less transient postoperative corneal thickening in the Healon GV/MicroVisc Plus group than in the Healon/MicroVisc group. CONCLUSIONS: Healon GV and MicroVisc Plus were safe and provided equal outcomes based on the parameters assessed. MicroVisc Plus' higher zero-shear viscosity caused it to behave slightly differently than Healon GV during surgery. More viscous, cohesive viscoelastics may increase surgical safety.

Adult↗
PubMed1997

Prospective, randomized trial of Microvisc and Healon in routine phacoemulsification.

PURPOSE: To compare the safety and efficacy of the new sodium hyaluronate viscoelastic, Microvisc, with those of Healon in routine phacoemulsification. SETTING: York Finch Eye Associates and York Finch General Hospital, Toronto, Ontario, Canada. METHODS: An unmasked, prospective, randomized clinical trial of 100 eyes in 100 patients having routine phacoemulsification and intraocular lens implantation was conducted to compare the safety and efficacy of Microvisc with those of Healon. Visual acuity, corneal thickness, and intraocular pressure were assessed preoperatively and at 6 hours, 1 and 5 days, and 1 and 6 months postoperatively. RESULTS: There were no statistically significant differences between the two treatment groups at any follow-up CONCLUSION: Based on the parameters assessed, both viscoelastic products were safe and provided comparable outcomes.

Adult↗
PubMed1997

HsS versus a balanced salt solution as a corneal wetting agent during routine cataract extraction and lens implantation.

PURPOSE: To evaluate HsS (elastoviscous hylan surgical shield, 0.45%) as an alternative to repeated corneal irrigation with a balanced salt solution during cataract surgery. SETTING: York Finch General Hospital, Toronto, Ontario (Center A), and Centre Hospitalier de St. Laurent, St. Laurent, Quebec (Center B), Canada. METHODS: This dual-center, randomized, prospective clinical trial comprised 60 patients (40 at Center A; 20 at Center B) who had routine small incision cataract surgery (Center A, endolenticular phacoemulsification; Center B, Khoury manual phacofragmentation) with in-the-bag implantation of a posterior chamber intraocular lens. The corneal irrigating fluid was randomly assigned to be HsS or a balanced salt solution. The frequency of required applications, duration of efficacy of each application, and assessment of corneal moisture, clarity, transparency, and reflection in the HsS and balanced salt solution groups were recorded and compared. RESULTS: Mean frequency of applications was 13.9 per procedure in the balanced salt solution group and 1.3 per procedure in the HsS group (P = .0001). Mean duration of effectiveness per application was 23.4 minutes for HsS and 2.0 minutes for balanced salt solution (P = .0001). No significant differences in safety or effect on corneal health were observed between the two solutions. CONCLUSION: The HsS was significantly more effective than a balanced salt solution in maintaining corneal moisture, clarity, and transparency. The use of HsS may be a safer, more effective option in ophthalmic surgery because it minimizes the obstructed visualization of the surgical field caused by frequent corneal irrigation and loss of surgeon concentration.

Acetates↗
PubMed1996

Pharmacotherapy of photorefractive keratectomy.

PURPOSE: To compare the pharmacotherapeutic practices of high-volume photorefractive keratectomy (PRK) surgeons with suggested practices gleaned from the current literature. SETTING: York Finch Eye Associates, Toronto, Canada. METHODS: Seventy-five ophthalmic surgeons believed by the authors to do a high-volume of PRKs were surveyed over the summer of 1994 about their pharmacotherapeutic practices. The results were compared with suggested practices extracted from a review of the current literature. RESULTS: Relatively consistent approaches to the management of post-PRK pain and prevention of acute post-PRK subepithelial infiltrative keratitis were reported. The administration of topical steroids after PRK was almost universally employed. Post-PRK analgesia was most commonly achieved with nonsteroidal anti-inflammatory drugs (NSAIDs) and a soft contact lens, but surgeons were not convinced of the benefits of long-term NSAID administration to control myopic regression and haze. There seemed to be no agreed-on solution to the infrequent problems of severe haze and regression and steroid-induced elevated intraocular pressure after PRK; however, many useful suggestions for the management of these problems were proposed. CONCLUSION: In general, high-volume PRK surgeons use topical steroids, NSAIDs, and a soft contact lens in the immediate postoperative period, although they are uncertain about the long-term effectiveness of NSAIDs in controlling regression and haze.

Analgesics↗
PubMed1981

Hyperornithinaemia and gyrate atrophy of the retina: improvement of vision during treatment with a low-arginine diet.

A 15-year-old patient with hyperornithinaemia (0.6--1.2 mmol/l) and gyrate atrophy of the retina was given a low-arginine diet to reduce plasma ornithine to a concentration (0.15--0.25 mmol/l) near the normal range. After five weeks of treatment, there was improvement in the visual function of one eye which had been severely impaired without improvement for 3 years. This improved visual function was maintained until compliance with the diet deteriorated at eight months, after which visual function regressed towards pretreatment status. Overrestriction of dietary arginine produced hyperammonaemia, indicating that arginine is an essential aminoacid in ornithine transaminase deficiency. These results suggest that reduction of plasma ornithine may reverse a metabolic neuroretinopathy in this disease, and offer hope that progression of the retinal atrophy can be arrested as well.

Adolescent↗
PubMed1981

Amino acids in retinitis pigmentosa.

A survey of fasting whole blood amino acids in 65 patients with various subtypes of retinitis pigmentosa performed. Eight X-linked recessive patients showed decreased taurine and aspartate. Nineteen autosomal recessive patients, and to lesser extent 10 autosomal dominant patients, showed reduced levels of whole blood threonine and histidine. Branched-chain amino acids and arginine were present in increased amounts in 2 patients with Laurence-Moon-Bardet-Biedl syndrome. These findings in LMBB patients are probably related in part to their obesity and emphasise that appropriate controls are required, and other factors (including age) known to affect amino acid levels must be accounted for. The biochemical implications of our findings are not yet apparent.

Adult↗
PubMed1980

Treatment of gyrate atrophy of the choroid and retina with low arginine diet.

In gyrate atrophy the blood ornithine is grossly elevated, due to deficiency of ornithine ketoacid transaminase, which converts ornithine towards glutamic acid. Two patients with gyrate atrophy have been treated with a low arginine diet and their blood ornithine levels have been reduced to near normal. At this level hyperammonemia may result from overtreatment, but this can be quickly cleared by a small dose of arginine. There has also been some improvement in vision, but no clearing of the gyrate areas. Future care with this regimen seems possible and improvements in handling of these patients are likely.

Adolescent↗
PubMed1979

Amino-acid metabolism and liver ultrastructure in hyperornithinemia with gyrate atrophy of the choroid and retina.

Three patients with the rare hyperornithinemia with gyrate atrophy of the choroid and retina (HOGA) syndrome were studied to elucidate the metabolic derangement and its pathologic concomitants. Tenfold elevations of blood ornithine levels, decreases in lysine levels, and hitherto unreported decreases in blood glutamate and glutamine concentration were observed. The output of ornithine from muscle kidney and splanchnic beds was curtailed or reversed after intravenous glucose. Levels of ornithine in venous blood declined after oral glucose, and rose after intravenous arginine. Increased amounts of 3-amino-2-piperidone were found in the urine, but these did not increase after the arginine-induced increase in ornithine levels. Liver biopsies in two patients revealed a marked alteration in mitochondrial ultrastructure. These studies extend the knowledge of the metabolic and pathologic derangements in HOGA. These findings are consistent with a disorder of ornithine-ketoacid transaminase, but such a disorder might not account for all the observations.

Adult↗
PubMed1978

Hyperornithinemia and gyrate atrophy of the choroid and retina.

The diagnosis of hyperornithinemia and gyrate atrophy (HOGA) depends upon the presence of five characteristic features: (1) typical chorioretinal lesions, (2) high myopia, (3) cataracts, (4) hyperornithinemia, and (5) autosomal recessive inheritance. We have seen three patients and described four new findings: (1) decreased whole blood glutamic acid, (2) low normal intelligence, (3) hepatic mitochondrial changes, and (4) urinary excretion of ornithine methyl ester. Investigations of amino acid metabolism in vivo are consistent with the presence of a defect in ornithine keto-acid transaminase.

Adult↗
PubMed1977

Infection and pheochromocytoma.

A urinary tract infection with possible septicemia and endocarditis developed in a 36-year-old man. The illness was complicated by pulmonary embolism, thrombocytopenia, hematemesis, hepatic dysfunction, paralytic ileus and accelerated hypertension. The latter finding suggested pheochromocytoma. Treatment with antibiotics and phenoxybenzamine hydrochloride was associated with notable clinical improvement. A chromaffin cell tumor was surgically removed above the lift kidney. Conclusively, a pheochromocytoma may mimic and be present in association with infection.

Adrenal Gland Neoplasms↗