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R Machemer

Publications and source records attributed to R Machemer.

At least 19 recordsLinked to original sources
PubMed2000

Exudative retinal detachment and retinitis associated with acquired syphilitic uveitis.

PURPOSE: To describe three cases of exudative retinal detachment and focal retinitis associated with acquired syphilitic uveitis. METHODS: Three patients who were referred for evaluation of uveitis were examined. Slit-lamp examination, ophthalmoscopy, B-scan ultrasonography, fundus photography, and fluorescein angiography were performed before and after therapy. RESULTS: Each patient had uveitis with exudative retinal detachment, periphlebitis, and focal retinitis. Laboratory testing (fluorescent treponemal antibody absorption) revealed positive serology for active syphilis in all cases. Human immunodeficiency virus antibody testing was negative in all patients. Retinal detachment resolved in all cases after treatment with intravenous penicillin. Despite resolution of subretinal fluid, visual acuity remained poor in eyes in which the macula was detached. CONCLUSION: Syphilis is a cause of exudative retinal detachment. Antibiotic therapy can lead to retinal reattachment. Early recognition and treatment may prevent severe vision loss.

Adult↗
PubMed1999

Appearance and rapid growth of retinal tumor (reactive astrocytic hyperplasia?).

BACKGROUND: Tumors of the retina are often seen in association with systemic syndromes such as neurofibromatosis, tuberous sclerosis, and von Hippel-Lindau disease. These masses are either astrocytic hamartomas or capillary hemangiomas. Retinal tumors unassociated with other systemic disease have also been reported. METHODS: The ophthalmologic evaluation and clinical course of a 65-year-old woman who developed an epiretinal membrane followed by a vascularized retinal mass in the macular area are described. RESULTS: Appearance and rapid growth of the lesion were documented with fundus photography and fluorescein angiography. The lesion was treated with photocoagulation following growth that threatened the foveal region. Choroidal neovascularization subsequently developed toward the fovea, and visual acuity has remained poor. After 4 years of follow-up no local recurrence or systemic disease possibly related to the tumor has occurred. CONCLUSIONS: This is the first report of documented appearance and rapid growth of a retinal tumor that resembles a reactive astrocytic hyperplasia.

Aged↗
PubMed1997

Adaptation to monocular torsion after macular translocation.

PURPOSE: To document the functional outcome of two patients following successful macular translocation for the treatment of severe subretinal hemorrhage in age-related maculopathy. METHODS: The retina was surgically rotated around the optic nerve with translocation of the fovea either upward or downward to an area of healthy retinal pigment epithelium. In the postoperative period, visual function was carefully studied with emphasis on adaptation to torsion. RESULTS: Visual acuity in one patient improved from 20/200 to 20/80 and the other patient remained at 20/200. Both patients developed horizontal and vertical strabismus with torsion of up to 55 degrees. After a prolonged period of occlusion of the unoperated eye, both patients were subjectively able to adapt to monocular torsion. However, adaptation under binocular conditions did not occur. CONCLUSION: Macular translocation was successful in improving visual acuity in one patient, with no improvement in the second. Both patients had significant ocular torsion and strabismus, but under monocular conditions they were successful in perceptually adapting to the change in the visual environment. Fear of cyclotorsion should not be a deterrent to considering macular translocation as a possible treatment option for severe subretinal macular hemorrhage if the patient is willing to accept monocular vision.

Adaptation, Ocular↗
PubMed1995

Long-term visual results of children after initially successful vitrectomy for stage V retinopathy of prematurity.

PURPOSE: To assess the effectiveness of vitrectomy for stage V retinopathy of prematurity (ROP) at the authors' institution, 33 patients with ROP who had initially successful total or partial anatomic retinal attachments (51 eyes) were evaluated for visual function and long-term anatomic stability. In addition, this study was an attempt to differentiate levels of visual function in children with very low vision and attendant developmental delays. METHODS: Visual function was assessed before retinal examination by an experienced pediatric vision specialist. The behavioral visual assessment was divided into seven segments with two to five tasks in each segment designed to establish a level of functional vision, ranging from light perception to form identification (and ambulation). The status of the retina was classified by the patient's retinal surgeon. RESULTS: The median follow-up was 61 months, and median age at the time of examination was 68 months. Of 51 eyes treated, form identification was achieved in 5, and all five patients had ambulatory vision. Of 51 eyes, 15 had no light perception, 11 had light perception, 6 could localize light, 10 could follow lights, and 4 were able to detect form. Only one eye in ten children with comparable ROP in each eye underwent surgery, and vision improved in six of ten of the surgical eyes. Redetachment was high, with 35 retinas totally or partially detached and only 13 retinas fully attached 61 months after surgery. CONCLUSION: The visual results are very low and disappointing. Initially successfully attached retinas can detach. There is some evidence that vitrectomized eyes function better than nonvitrectomized eyes. There is also evidence that visual function lower than form identification is useful to these children and that they are able to use their limited vision better than previously though.

Child↗
PubMed1994

Treatment and pathogenesis of traumatic chorioretinal rupture (sclopetaria).

Eight eyes (seven patients) with traumatic chorioretinal rupture (sclopetaria) from severe ocular trauma were examined. All seven patients were referred with diagnoses of retinal detachment, giant retinal tear, or ruptured globe. Instead, all eyes had large, peripheral, full-thickness breaks of the choroid and retina without retinal detachment. Seven of eight eyes were initially managed by observation only; one eye was treated with a scleral buckling procedure. The retina remained attached in all eyes for at least six months. Late retinal detachment (more than one year after initial injury) occurred in two eyes because of retinal breaks at a site distant from the original chorioretinal rupture. Two eyes later developed vitreous hemorrhage associated with posterior vitreous detachment and one of these eyes required vitrectomy to clear the visual axis. The pathogenesis of sclopetaria appears to be mechanical disruption and retraction of tissue rather than acute tissue dissolution. The risk of acute retinal detachment is low. We recommend nonsurgical management for the initial treatment of these patients, with continued observation for complications that may later occur.

Adolescent↗
PubMed1994

The efficacy of silicone oil for complicated retinal detachments in the pediatric population.

OBJECTIVE: To evaluate the efficacy of silicone oil as an intraocular tamponade for complicated retinal detachments in the pediatric population. DESIGN: Case series. SETTING: Referral practice at a major university hospital eye center. PATIENTS: Consecutive referred sample of 48 cases of complicated retinal detachments in children 16 years old or younger. Forty-two percent of the patients had traumatic injuries, and 35 of the eyes had undergone at least one previous retinal surgery. The minimum follow-up was 6 months, with an average follow-up of 23 months. INTERVENTIONS: Pars plana vitrectomy, silicone oil injection, and advanced vitreoretinal surgical techniques. MAIN OUTCOME MEASURES: Successful repair of complicated retinal detachment, improved visual acuity post-operatively, and frequency of complications. RESULTS: The postoperative visual acuity at the last follow-up examination was counting fingers or better in eight (17%) of the 48 cases, and only two eyes saw 20/200 or better. In the 46 eyes in which the retinal status could be determined, 16 retinas (35%) were successfully reattached at last follow-up. Significant complications included corneal opacification (62%) and hypotony (58%). Postoperative glaucoma was not a problem. CONCLUSIONS: In the pediatric population with complicated retinal detachments, silicone oil used for intraocular tamponade has disappointing results due to a low rate of sustained retinal reattachment, poor visual rehabilitation, and a high complication rate.

Adolescent↗
PubMed1994

Growth inhibition of human Tenon's capsule fibroblasts and rabbit dermal fibroblasts with non-carcinogenic N-alkylated anthracyclines.

Bleb fibrosis after glaucoma filtering surgery and proliferative vitreoretinopathy after retinal detachment surgery are complications caused by proliferation of fibroblasts or fibroblastlike cells. The anthracycline daunomycin (DNM) has been used for treatment of those proliferative processes in humans. However, complications such as conjunctival necrosis and corneal or scleral ulcerations have been reported after administration of DNM to glaucoma patients. Intravitreal administration of DNM in rabbit eyes resulted in morphological and functional retinal damage. DNM also has the undesired general effect of carcinogenicity. N-Alkylation of the aminosugar moiety of DNM results in reduction or loss of carcinogenicity. We evaluated the inhibitory effect of the new non-carcinogenic N-alkylated analogues aclacinomycin A (ACA), N,N-dimethyladriamycin (AD280), and N-trifluoroacetyladriamycin-14-O-hemiadipate (AD143) on the growth of cultured human Tenon's capsule fibroblasts and rabbit dermal fibroblasts. Using DNM as a positive control, we conducted proliferation assays that demonstrated that ACA and AD280 inhibited fibroblast growth as effectively as DNM. AD143 was less efficacious. The magnitude of cellular growth inhibition was concentration dependent for all drugs tested. Extension of exposure times resulted in increased rates of cell death. Our in vitro studies suggest that further evaluation of ACA and AD280 should be carried out in animal models of ocular proliferative disorders.

Animals↗
PubMed1994

Edward W.D. Norton.

Explore the source record for details and available documents.

History, 20th Century↗
PubMed1993

N,N-dimethyladriamycin for treatment of experimental proliferative vitreoretinopathy: efficacy and toxicity on the rabbit retina.

N,N-Dimethyladriamycin (Me-2-ADM) derives from adriamycin (doxorubicin) by N-methylation of its aminosugar moiety. In contrast to the parent agent, Me-2-ADM lacks mutagenicity and carcinogenicity. To evaluate its suitability for treatment of proliferative vitreoretinopathy (PVR), we studied the ability of Me-2-ADM to prevent traction retinal detachment in a model of PVR in rabbits. The model was created by intravitreal injection of 25,000 homologous dermal fibroblasts after vitreous gas compression. Two days after fibroblast injection, 5, 10 or 30 nmol Me-2-ADM was administered into the vitreous cavity. The control group received sham injections. All control eyes developed traction retinal detachments. Administration of 5 nmol Me-2-ADM slightly reduced the rate of retinal detachments to 90%. No retinal detachments occurred in the group treated with 10 nmol Me-2-ADM while 11% of eyes treated with 30 nmol Me-2-ADM developed retinal detachments. At day 28 of the study, light microscopic examination of retinas treated with 30 nmol Me-2-ADM revealed severe retinal damage while no such damage was present in eyes treated with 10 nmol. To exclude early retinal damage, 10 nmol Me-2-ADM were injected into eyes that had undergone vitreous gas compression but no fibroblast injection. On day 3, 7, and 14 after drug administration, ERGs were recorded simultaneously from drug treated and sham treated (contralateral) eyes. Light microscopy and transmission electron microscopy (TEM) were performed. Only transient ERG changes were observed at day 7, which recovered by day 14. All morphological findings in drug exposed eyes were in the range of normal when compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Late traction detachment in retinopathy of prematurity or ROP-like cases.

Five cases of traction retinal detachment occurring later in life as a sequel of cicatricial retinopathy of prematurity or showing the clinical picture of retinopathy of prematurity are reported. They presented with taut membranes in vitreous cavity, causing traction retinal detachment, and often showed preretinal membranes. These membranes were collagen-rich and contained cells with glial characteristics. They seemed to be continuously produced on the surface of the retina from which they detached sometimes in multiple generations. It is likely that chronic exudation from vascular abnormalities is a stimulus for this proliferation. These cases are very similar to other vitreoretinal proliferations in association with vascular abnormalities (Coats' and von Hippel disease, exudative vitreoretinopathy).

Adult↗