Search PubMed⌕ Search

Biomedical subjects

P Sternberg

Publications and source records attributed to P Sternberg.

At least 91 records · Page 5Linked to original sources
PubMed1989

A donor-age-dependent change in the activity of alpha-mannosidase in human cultured RPE cells.

Six acidic glycosidase activities in cultured human retinal pigment epithelium (RPE) cells from donors of different ages (19 to 80 years) were studied with regard to pH optimum, Km, Vmax and specific activity. For alpha-mannosidase we found significant age-dependent decreases in specific activity and Vmax but not in Km. The other glycosidases and acid phosphatase, lactate dehydrogenase (LDH) and citrate synthase showed no change in these parameters with donor age. The alpha mannosidase activity of older donor cells could be activated almost 2-fold by the addition of zinc. This is the first report of age-dependent change in a human RPE lysosomal enzyme. Since alpha-mannosidase is probably required for the degradation of rhodopsin in the phagolysosomal system of the RPE, decrease in this enzyme activity may lead to accumulation of undigested rod outer segments (ROS) and drusen, both of which are associated with age-related macular degeneration (AMD).

Adult↗
PubMed1989

Vitrectomy when asteroid hyalosis prevents laser photocoagulation.

Asteroid hyalosis is a relatively common disorder of the vitreous that rarely causes visual impairment. However, funduscopic examination and laser photocoagulation can be difficult because of reflections off the asteroid bodies. Although vitrectomy is rarely indicated for impaired visual acuity, we report three cases in which pars plana vitrectomy was necessary to permit required retinal laser photocoagulation. In two patients with proliferative diabetic retinopathy and a third patient with subretinal neovascularization marked asteroid hyalosis precluded photocoagulation by standard techniques.

Aged↗
PubMed1988

Photocoagulation to prevent retinal detachment in acute retinal necrosis.

Retinal detachment (RD) occurs in more than 50% of eyes with acute retinal necrosis (ARN) and is the leading cause of visual loss in this syndrome. In order to decrease the incidence of RD in ARN, the authors treated 12 eyes of 10 patients with prophylactic laser photocoagulation. Retinal detachment occurred in two eyes (17%). Over the same time period, seven eyes with ARN did not receive prophylactic laser treatment, most often because of dense vitreous debris, with a 67% rate of RD. Prophylactic photocoagulation treatment should be considered in the management of patients with ARN.

Acute Disease↗
PubMed1988

Sutureless scleral buckle for retinal detachment with thin sclera.

Retinal detachment surgery can be hazardous in the presence of thin sclera, with increased risk of inadvertent perforation. We designed polymethylmethacrylate belt loops that can be fixed to the sclera with cyanoacrylate tissue adhesive, allowing 360 degrees scleral buckling to be performed without sutures. We report the successful use of this technique in a three-year-old girl with a rhegmatogenous retinal detachment and blue sclerae.

Child, Preschool↗
PubMed1986

Treatment of dislocated posterior chamber intraocular lenses.

We treated five patients with posterior chamber intraocular lenses that were dislocated into the vitreous cavity. Using a pars plana approach, a vitrectomy was performed, and the intraocular lens was grasped with forceps and repositioned behind the iris with the lens loops in the ciliary sulcus. The loops were sutured to the iris in four cases. Visual acuity returned to 20/25, or better, in each case.

Aged↗
PubMed1986

Acute retinal necrosis syndrome following herpes zoster dermatitis.

The acute retinal necrosis (ARN) syndrome has been recently linked to intraocular infection with one or more members of the herpesvirus family. The authors report two cases of ARN following herpes zoster skin eruptions, and one case following ipsilateral facial nerve palsy (Ramsay Hunt syndrome). Evaluation of serial serum antibody titers against cytomegalovirus (CMV), herpes simplex virus (HSV) (types 1 and 2), and varicella zoster (VZ) virus revealed diagnostic changes for VZ virus alone following the retinitis. Immune precipitation of radiolabeled VZ proteins by these sera followed by gel fractionation yielded radioimmune precipitation profiles characteristic of a recent zoster reactivation. These cases further implicate a central role for VZ virus infection in the etiology of the ARN syndrome.

Acute Disease↗
PubMed1986

Respiratory arrest following retrobulbar anesthesia.

Respiratory arrest is a serious complication of retrobulbar anesthesia. We have prospectively followed 3123 retrobulbar injections to determine the incidence of respiratory arrest and identify possible risk factors. Injections contained either 2% or 4% lidocaine with 0.75% bupivacaine (Marcaine) in a 50:50 mixture by volume (total 10 cc.) to which a 1 ml ampule of hyaluronidase (150 NF units) was added. Use of 4% lidocaine gave a significantly higher incidence of respiratory arrest than 2% lidocaine (0.79% vs. 0.09%; P = 0.003, Fisher's exact test). Serum levels of lidocaine and bupivacaine of patients who arrested were not elevated significantly compared to 20 control patients. All levels were well below accepted levels of toxicity. Thus, 4% lidocaine increases the risk of respiratory arrest. These results suggest the mechanism is not direct intravascular or central nervous system injection.

Adult↗
PubMed1985

Results of conventional vitreous surgery for proliferative vitreoretinopathy.

During a five-year period (1978 through 1982), we used conventional vitreous surgery techniques to treat patients who had recurrent retinal detachment as the result of proliferative vitreoretinopathy. At a six-month follow-up, 24 (33%) of 72 patients achieved total retinal reattachment; 14 patients regained ambulatory vision (5/200 or better) after one operation. Only 12 patients were reoperated on; four achieved retinal reattachment. Anatomic success correlated with a lesser grade of proliferative vitreoretinopathy and an absence of detectable retinal breaks. Creation of iatrogenic retinal tears and broad scleral buckling and an extended interval between the initial detachment and vitreous surgery did not improve the prognosis.

Eye Diseases↗
PubMed1985

The effect of silicone oil on the cornea.

Intraocular silicone oil tamponade is being used with increasing frequency as an adjunct to conventional vitrectomy techniques in the treatment of proliferative vitreoretinopathy. When used in patients with aphakia, corneal decompensation is a common long-term complication. In this study, we evaluated the clinical and morphologic changes that occurred in the corneas of 14 rabbits and seven cats when the anterior chamber was filled with silicone oil. Within six days, wide-field specular microscopy showed a 40% reduction in endothelial density in the area of the silicone oil bubble in both groups. Progressive stromal thinning occurred in the rabbit cornea, with gradual development of a retrocorneal membrane at the junction of silicone-endothelial cell contact. In contrast, persistent stromal edema, peripheral vascularization, irregular plaques on the endothelium, and eventual epithelial ulceration and corneal thinning occurred in cat eyes.

Animals↗
PubMed1984

Subretinal proliferation.

Subretinal proliferation is often present but less often identified as a component of proliferative vitreoretinopathy. Subretinal membranes form from retinal pigment epithelial cells and retinal glial cells that migrate into the subretinal space of eyes with long-standing retinal detachments. The membranes grow as sheets but break up into bands as the cells contract, with the stronger parts remaining intact.

Adolescent↗
PubMed1984

Multivariate analysis of prognostic factors in penetrating ocular injuries.

We used a multivariate statistical analysis to identify factors predicting visual outcome in 281 eyes that underwent primary repair of a penetrating ocular injury. Visual acuity of 20/800 or better on initial examination was the most important factor, with these eyes 28 times more likely to have a final visual acuity of 20/800 or better than eyes with initial visual acuities worse than 20/800. The effect of other factors differed depending on the initial visual acuity. In patients with initial visual acuities of 20/800 or better, youth (less than or equal to 18 years) was a significant predictor of final visual acuities of 20/50 or better. In patients with initial visual acuities worse than 20/800, a laceration limited to the cornea was the best predictor of good visual outcome. Absence of an expelled or subluxed lens and lacerations limited to a location anterior to the rectus muscle insertions were also important predictors of good visual outcome. When an intraocular foreign body was present these factors were no longer significant and older age (greater than 18 years) was the most important predictor of good visual outcome.

Adolescent↗
PubMed1984

Evaluation of vitrectomy in penetrating ocular trauma. A case-control study.

A case-control retrospective evaluation of vitrectomy in penetrating ocular trauma was performed by matching 89 eyes, managed with vitrectomy, with 89 similar eyes that did not undergo vitrectomy. The cases were matched according to factors previously shown to correlate with the visual outcome, including the following: (1) type of trauma; (2) length and posterior extent of the laceration; (3) type and degree of lens involvement; and (4) type and location of any intraocular foreign body. The groups differed in the distribution of initial visual acuity, which was worse in the vitrectomy group. When the final visual results were compared, no statistical advantage from vitrectomy was found. However, beneficial trends were demonstrated in air rifle and double-penetrating injuries, as well as in other severe injuries in which initial visual acuity was worse than 5/200.

Adolescent↗
PubMed1984

Controlled aspiration of subretinal fluid in the diagnosis of carcinoma metastatic to the choroid.

Carcinoma metastatic to the choroid was diagnosed in three patients by cytopathologic examination of subretinal fluid. The specimen was obtained using a scleral depressor modified to allow controlled aspiration of subretinal fluid through a sharp, angled, 30-gauge needle. This new method provides a useful tool for accurate diagnosis of carcinoma metastatic to the choroid in cases where the diagnosis is in question.

Adenocarcinoma↗