PubMed Health⌕ Search

Biomedical subjects

A Sugar

Publications and source records attributed to A Sugar.

At least 19 recordsLinked to original sources
PubMed1992

Optisol corneal storage medium.

We compared the safety and efficacy of Optisol (Chiron Ophthalmics, Irvine, California), a new corneal storage medium, with McCarey-Kaufman and Dexsol corneal storage media (Chiron Ophthalmics, Irvine, California) and K-Sol corneal storage medium (Cilco, Huntington, West Virginia). Optisol contains dextran, 2.5% chondroitin sulfate, vitamins, and precursors of adenosine triphosphate (adenosine, inosine, and adenine). In in vitro studies, rabbit and human corneas stored in Optisol were thinner after 12 to 14 days at 4 C than tissue stored in other media. Thymidine uptake showed increased mitotic activity in human corneal endothelial cells cultured in Optisol, compared to Dexsol. Specular microscopic fields showed larger are-as of visibly intact endothelial cells and ultrastructural examination disclosed fewer structural changes in endothelial cells stored in Optisol, compared to tissue stored in Dexsol. In vivo, no clinical signs of epithelial toxicity or histologic evidence of intraocular inflammation were observed in rabbit eyes in which Optisol drops were instilled four times a day for 14 days. Finally, 51 patients undergoing penetrating keratoplasty with tissue stored in Optisol for one to six days (mean, 3.6 days) were enrolled in an uncontrolled, open-label clinical study. The percentage of clear grafts (93%, 41 of 44 patients examined at three months; and 98%, 42 of 43 patients examined at six months) and endothelial cell loss (5.0% and 11.5% at three and six months, respectively) were comparable to data from previous studies that used tissue stored in other short-term and intermediate-term media. The results suggest that Optisol storage preserves corneal endothelial cells for up to two weeks at 4 C, thereby permitting flexibility in the use of donor tissue for corneal transplantation, and that Optisol storage yields thinner tissue, which may allow for more accurate evaluation and more effective surgical manipulation.

Adult↗
PubMed1992

A randomized, prospective, double-masked clinical trial of Optisol vs DexSol corneal storage media.

We compared Optisol and DexSol, two chondroitin-sulfate-based media for corneal storage at 4 degrees C, by transplanting 31 donor cornea pairs (one cornea stored in Optisol and its mate in DexSol for 20 to 134 hours) into 31 pairs of recipients (62 patients). All grafts were clear 1 year after transplantation except for one primary donor failure (Optisol group). Optisol-stored corneas were significantly thinner than DexSol-stored corneas after cardinal suture placement (0.64 mm vs 0.76 mm) and at the end of surgery (0.69 mm vs 0.78 mm); at all points afterward through 1 year the two groups did not differ. The activity of two lysosomal enzymes released into the media during storage, alpha-mannosidase and alpha-glucosidase, was lower in the Optisol group. Epithelial status and all endothelial morphometric parameters, except the figure coefficient at 1 year, did not differ between the two groups before surgery and 3, 6, and 12 months after surgery. Mean endothelial cell loss at 1 year was 15% for the Optisol group and 21% for the DexSol group (P = .22). Thus, Optisol-stored corneas were thinner during surgery than DexSol-stored corneas and there was less lysosomal enzyme activity in the Optisol medium after tissue storage. There were no significant differences in postoperative clinical or endothelial morphometric parameters, however.

Adult↗
PubMed1992

Lag screws in sagittal split osteotomies: should they be removed?

The use of stainless steel lag screws to provide rigid internal fixation for sagittal split osteotomies was first described more than 17 years ago. It was shown that the need for intermaxillary fixation could be eliminated and that lower relapse rates could be produced. However a decade later, removal of the screws was still being advocated. In this study, 48 patients had a total of 259 screws inserted over a 5 year period. Twenty six screws were removed 10 months following insertion. Most of these were removed in the absence of any symptoms although a few were palpable or tender to touch. None of the screws removed were loose nor was there any evidence of infection or corrosion associated with them. The long term consequences of screw retention are discussed and it is suggested that they do not need to be removed routinely.

Adolescent↗
PubMed1992

Intercellular adhesion molecule-1 (ICAM-1) and HLA-DR antigens in herpes keratitis.

PURPOSE: Intercellular adhesion molecule-1 (ICAM-1) is a cell surface glycoprotein that binds leukocyte function antigen-1 receptor on leukocytes, thereby regulating leukocyte trafficking and function at sites of inflammation. Recently, the authors demonstrated ICAM-1 in human corneas exposed to proinflammatory cytokines, but ICAM-1 has not been reported in corneal disease. In this study, the presence of ICAM-1 in human disciform herpes simplex virus (HSV) keratitis is investigated. METHODS: Immunohistochemistry was performed for ICAM-1 on 4 keratoplasty specimens from patients with corneal scarring due to disciform HSV keratitis and 1 corneoscleral biopsy of a patient with active HSV keratoscleritis using specific, characterized monoclonal antibody to ICAM-1. Negative immunohistochemical controls included monoclonal antibodies to other vascular endothelial adhesion molecules or mouse serum. RESULTS: All 5 specimens demonstrated intense ICAM-1 immunoreactivity of keratinocytes, stromal keratocytes, and endothelial cells, predominantly in regions of leukocytic infiltration. Diffuse, intense HLA-DR positivity was detected throughout the corneas. The specimens failed to react with control antibodies. CONCLUSION: These results are the first to demonstrate ICAM-1 in human corneal disease and suggest important roles for ICAM-1 and HLA-DR co-expression in generating immune responses in HSV keratitis. Increased ICAM-1 expression in regions of leukocytic infiltration may regulate leukocyte-corneal cell binding, thereby promoting immune responses and damage by activated leukocytes.

Adult↗
PubMed1992

Secondary localized amyloidosis in interstitial keratitis. Clinicopathologic findings.

Cases of secondary localized corneal amyloidosis have been described in various corneal and ocular inflammations but are believed to occur uncommonly. The authors examined histopathologic specimens from 33 consecutive patients with interstitial keratitis who underwent penetrating keratoplasty for visual rehabilitation. In 11 cases (33%), multiple fusiform deposits of amyloid were identified and confirmed in middle and deep corneal stroma using histochemical staining. Characteristic electron microscopic findings were present in two cases. These results indicate that secondary localized corneal amyloidosis occurs frequently in interstitial keratitis and displays a distinct pattern of deposition.

Aged↗
PubMed1992

Toxoplasma encephalitis in patients with the acquired immunodeficiency syndrome.

Among 504 cases of AIDS diagnosed between 1983 and 1990, there were 86 patients (17%) with toxoplasma encephalitis (TE). All were symptomatic at the time of diagnosis. General signs such as fever, neck stiffness, or headache were present in 87.2%, and 75.6% had focal signs. The primary means of diagnosis was computerized tomographic scanning, revealing 169 lesions of which 80% were immediately contrast-enhancing. All patients had IgG antibodies against Toxoplasma gondii either before (74 of 75 evaluable patients) or at the time of diagnosis of TE (73 of 75). Elevated antibody titers were present in 44% of evaluable patients, compared to 11% of patients with AIDS and other opportunistic infections. Initial treatment was pyrimethamine plus sulfonamides in 65 patients, and pyrimethamine plus clindamycin in 12 patients, with other combinations or no treatment accounting for the remainder. Life-table analysis of the time to discontinuation of treatment because of suspected side effects suggested that sulfadiazine was significantly more toxic, with 48% of patients experiencing an interruption in treatment after 30 days, than pyrimethamine (12%) or clindamycin (24%). The 30-day mortality rate was 12%, and median survival was 310 days after diagnosis, 530 in patients treated with zidovudine and 190 days in those not so treated. Of 82 evaluable patients, 16 relapsed once and 4 of these more than once. The risk of relapse was 27% 1 year after diagnosis of a first episode of TE.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Implantation of Kelman-style, open-loop anterior chamber lenses during keratoplasty for aphakic and pseudophakic bullous keratopathy. A comparison with iris-sutured posterior chamber lenses.

The clinical and specular microscopic results of 40 cases (39 patients) of penetrating keratoplasty during which a Kelman-style anterior chamber intraocular lens was implanted were reviewed retrospectively. Thirty-one pseudophakic eyes received an intraocular lens exchange and nine aphakic eyes received a secondary intraocular lens. Postoperative follow-up averaged 24.5 months (range, 3 to 51 months). At 1, 2, and 3 years after keratoplasty, 39.3%, 63.2%, and 63.6% of eyes, respectively, had visual acuities of 20/40 or better. Ninety-five percent of the grafts remained clear. Causes of poor postoperative visual acuity included cystoid macular edema (32.5%), new glaucoma (22.5%), and age-related macular degeneration (10.0%). Other causes were endothelial rejection leading to graft failure, corneal ulceration, and retinal detachment. Corneal endothelial cell loss by specular microscopy was 11.5% at 1 years, 21.3% at 2 years, and 25.0% at 3 years. These results were compared with cell loss associated with iris-sutured posterior chamber lenses in penetrating keratoplasty. Visual outcomes and complication rates were similar between these two methods; however, the endothelial attrition at 1 and 2 years for the sutured posterior chamber lens was greater than that of the Kelman anterior chamber lens.

Adult↗
PubMed1979

The ocular manifestations and functional effects of occupational argyrosis.

Thirty employees of an industrial plant involved in the manufacture of silver nitrate and silver oxide underwent ophthalmologic evaluation in an effort to evaluate the frequency and extent of ocular argyrosis. The most frequently noted ocular abnormality was pigmentation of the conjunctiva, present in 20 workers; corneal pigmentation occurred in 15 workers. A direct relationship existed between the levels of pigmentation and duration of employment. Ocular pigmentation was seen more frequently than cutaneous pigmentation. Ten workers noted decreased night vision, but electrophysiologic and psychophysiologic studies of seven of these ten workers demonstrated no functional deficits.

Adult↗
PubMed1979

Time analysis of corneal endothelial cell density after cataract extraction.

Serial endothelial photographs were taken preoperatively and postoperatively in 200 eyes; 111 eyes contained a Rayner iris clip lens, 54 eyes contained a Fyodorov Sputnik lens, and 35 eyes had no lens. Central endothelial cell density was changed in all instances, with counts in implanted eyes declining 25 to 30%, and in nonimplanted eyes 10 to 15%. In both instances, the decline essentially ceased at about three months. The cause of the greater decline in implanted eyes appeared to be mechanical and subsequent cell loss after the 90-day period was virtually equal for the two groups. Methods that may be used to alter the difference in cell density occurring with implantation are best analyzed by using the 90-day period data for comparison.

Animals↗
PubMed1979

Binkhorst Lecture (Part 1). Experimental cataract surgery.

The use of intraocular lenses in cataract surgery leads to a greater corneal complication rate than surgical treatment without such devices. It has been assumed that the predominant reason for this is surgical trauma at the time of lens insertion. A laboratory study to verify and analyze this difference has been carried out, the cat being used as an experimental model. This first report evaluates the effect of the usual steps of cataract extraction on the density of corneal endothelial cells.

Animals↗
PubMed1977

Epithelial downgrowth following penetrating keratoplasty in the aphake.

Four of approximately 1,500 patients receiving corneal grafts developed epithelial downgrowth following penetrating keratoplasty. All were aphakic prior to grafting and had complicated postoperative courses. Epithelial proliferation over the iris and endothelium was demonstrated in three cases at the time of a repeat keratoplasty. While rare, this complication may occur more frequently than has been previously recognized.

Aged↗