Search PubMed⌕ Search

Biomedical subjects

W F Mieler

Publications and source records attributed to W F Mieler.

At least 19 recordsLinked to original sources
PubMed1992

Posterior segment changes in membranoproliferative glomerulonephritis.

Membranoproliferative glomerulonephritis is a renal disorder characterized by proliferation of cells and changes in the basement membrane of the glomerulus. The disease is divided into three subtypes: type I, characterized by the presence of subendothelial electrondense deposits; type II, characterized by deposition of electrondense material of unknown origin in the lamina densa of the glomerular basement membrane; and type III, characterized by lesions having both type I and type II qualities. Specific posterior segment changes have been reported with membranoproliferative glomerulonephritis type II. We examined three patients with membranoproliferative glomerulonephritis type II and two patients with type III disease. All three patients with type II disease had Bruch's membrane and retinal pigment epithelial changes, whereas both patients with type III disease had normal posterior segments.

Adult↗
PubMed1992

Macular phototoxicity caused by fiberoptic endoillumination during pars plana vitrectomy.

Three cases of retinal phototoxicity were caused by light from the endoilluminator used in vitrectomy. Preoperative clinical examination, color photography, and fluorescein angiography in all three cases failed to disclose retinal pigment epithelial changes. Postoperative clinical findings, photographs, and fluorescein angiograms are highly suggestive of the presence of retinal phototoxicity. The characteristics of these lesions and surgical conditions implicate the endoilluminator as the source of photic injury. The macular lesions were noted within one week of the surgical procedure, measured between 2 and 5 disk diameters in size, involved the fovea in two eyes, and resulted in marked decrease in visual acuity in two of three eyes, with persistence in one eye. Initially, whitening of the outer retina was present, but was replaced by pigmentary mottling at the level of the retinal pigment epithelium within a few weeks. Preventive measures to avoid macular phototoxicity associated with vitrectomy are discussed.

Adult↗
PubMed1992

Submacular fibrosis after photocoagulation for diabetic macular edema.

Ten eyes of nine patients developed submacular fibrotic scars without fluorescein angiographic evidence of choroidal neovascularization between two and 11 months (mean, 6.1 months) after argon laser treatment for diabetic macular edema. In four eyes, development of the subretinal scar was associated with visual acuity loss of two, two, four, and eight lines of Snellen visual acuity, respectively, within five to 11 months of laser treatment. At the final follow-up visit, the visual acuity of the eyes with two lines of visual acuity loss had returned to within one line of the initial value, but the visual acuity of the eyes with more severe initial visual acuity loss did not recover notably. In four eyes, fibrous submacular strands extended from macular laser scars, suggesting an iatrogenic role of the laser in inducing this complication.

Aged↗
PubMed1992

Combined phacoemulsification, pars plana vitrectomy, and posterior chamber intraocular lens insertion.

Eighteen eyes with coexisting cataract and vitreoretinal disease underwent combined phacoemulsification, pars plana vitrectomy, and posterior chamber lens implantation. Preoperative vitreoretinal disease included nonclearing vitreous hemorrhage (eight eyes), vitreous hemorrhage and tractional retinal detachment (three eyes), tractional retinal detachment (one eye), epiretinal membranes (three eyes), peripheral uveitis (two eyes), and a retained intraocular metallic foreign body (one eye). Postoperative visual acuity improved in each case; 14 eyes achieved visual acuity between 20/20 and 20/80 during an average postoperative period of 11 months (range, 3 to 39 months). Perioperative complications included an iatrogenic retinal break (one eye) and pupillary block glaucoma (one eye). Four eyes required YAG laser capsulotomy postoperatively. Phacoemulsification did not interfere with corneal clarity, allowed water-tight wound closure during vitrectomy, and preserved the capsular bag, allowing endocapsular fixation of the posterior chamber lens. Combining phacoemulsification, posterior chamber lens implantation, and pars plana vitrectomy allows rapid visual rehabilitation and functional unaided vision in these eyes.

Adult↗
PubMed1992

The lowest effective dose of tissue plasminogen activator for fibrinolysis of postvitrectomy fibrin.

Tissue plasminogen activator (tPA) has been shown to be effective at a dose of 25 micrograms in the treatment of severe postvitrectomy fibrin. However, a recent report based on an animal model indicates that retinal toxicity may occur at doses as low as 25 micrograms. This study uses a low dose (1.5 micrograms to 3 micrograms) of tPA for 34 injections in 26 eyes, and determines the lowest effective dose to be between 1.5 and 3 micrograms. Complete fibrinolysis was achieved in all 28 eyes in which 3 micrograms of tPA was administered within 10 days of vitrectomy, whereas partial fibrinolysis was achieved in eyes treated with 3 micrograms of tPA 27 days and 82 days after vitrectomy. Complete fibrinolysis occurred in only 1 of 4 eyes that receive 1.5 micrograms of tPA. A dose of 3 micrograms of tPA is recommended for treatment of severe fibrin after vitrectomy, as it has a wider margin of safety than do higher doses.

Adolescent↗
PubMed1992

Favourable outcome of traumatic endophthalmitis with associated retinal breaks or detachment.

Traumatic endophthalmitis in association with retinal breaks or detachments is reported to have uniformly poor visual and anatomic outcomes. We describe two cases of culture-positive traumatic endophthalmitis with retinal breaks or detachment in which the final visual result was 20/70 in one case and 20/40 in the other. Factors that may improve the prognosis in such cases include attention to the possibility of infection, selective use of broad-spectrum antibiotics, prompt surgical intervention and improvement in vitreous surgical techniques. Modification of intravitreal antibiotic regimens may be indicated in eyes in which the vitreous cavity is partially filled with air or gas.

Adolescent↗
PubMed1992

Hemorrhage associated with localization of melanoma margins during radioactive plaque placement.

Accurate placement of a radioactive plaque is essential in brachytherapy of choroidal melanoma. Various localization techniques, including transillumination of anteriorly located tumours and scleral indentation to mark the anterior margin of posteriorly located tumours, have been used in initially placing a plaque over the base of the tumour. Of 40 consecutive patients treated for choroidal melanoma between 1986 and 1990, 8 had posteriorly located tumours, all localized by means of scleral indentation; subretinal hemorrhage occurred in 3 of the 8 during marking of the tumour margins. No hemorrhages occurred in the 32 patients with tumours localized by means of transillumination (p less than 0.01). It is not clear whether the method of marking or the location of the tumour itself contributed to the development of the hemorrhage. Hemorrhage around the base of a tumour may mask the tumour margins, making assessment of the response to therapy difficult. Caution should be used when marking posteriorly located tumours.

Aged↗
PubMed1992

Sclerochoroidal calcification.

We studied 19 patients with sclerochoroidal calcification. The findings were bilateral in 16 patients and unilateral in the remaining three patients. The lesions, which were usually multifocal, had two characteristic appearances, plaque-like and tumorlike. Eleven patients had relatively flat, irregularly shaped, plaque-like, yellow-white lesions located between the arcades and the equator. Eight patients had more elevated tumorlike lesions, ranging up to 6 mm in height. All showed patterns on echography consistent with calcification. The calcification was often documented in both the choroid and sclera; sometimes it appeared only in the choroid, but never only in the sclera. Calcium metabolism appeared to be normal in all but two of the nine patients in whom it was investigated. Idiopathic sclerochoroidal calcification has a characteristic echographic and ophthalmoscopic appearance and may be more common than has been realized.

Aged↗
PubMed1991

Decrease in the risk of bilateral acute retinal necrosis by acyclovir therapy.

We reviewed the course of 54 patients who had unilateral acute retinal necrosis at initial examination. Thirty-one patients were treated with acyclovir, whereas 23 were not. Of the 31 patients treated with acyclovir, 27 (87.1%) had fellow eyes that remained disease-free throughout a median follow-up of 12 months. Of the 23 patients not treated with acyclovir, seven (30.4%) had fellow eyes that remained disease-free throughout a median follow-up of 11 months. Survival analysis indicated that the fellow eyes of the group of patients treated with acyclovir were more likely to remain disease-free than the fellow eyes of the group not treated with acyclovir (P = .0013). Two years after initial onset, the proportion of fellow eyes that remained disease-free was 75.3% for the group treated with acyclovir and 35.1% for the group not treated with acyclovir. These results suggest that acyclovir treatment reduces the risk of involvement of the fellow eye in patients with acute retinal necrosis.

Acyclovir↗
PubMed1991

Penetrating ocular injury from contaminated eating utensils.

Although the rate of infectious endophthalmitis following penetrating ocular injury is generally less than 10%, certain settings may carry a greater risk of infection. One such setting is penetrating injury resulting from eating utensils contaminated with oral flora. We reviewed six of these injuries. Culture-positive bacterial endophthalmitis developed in four of the six eyes; only one of the eyes retained reading visual acuity (greater than 20/50) and two eyes lost light perception. The potential for infection and limited visual outcome in this series warrants aggressive prophylaxis and treatment. The unexpected isolation of Haemophilus influenzae in two of the four infections suggests that broad-spectrum antibiotic treatment should be considered in all such injuries since less common organisms may be encountered.

Adult↗
PubMed1991

Ocular injuries caused by elastic cords.

Five patients with ocular trauma due to elastic cords with attached metal or plastic hooks were evaluated over a 13-month period. Injuries included hyphema, angle recession, lens subluxation, choroidal rupture, vitreous hemorrhage, retinal detachment, and scleral rupture. Two patients suffered penetrating ocular injuries, and three patients had final visual acuities of 20/200 or less. This series emphasizes the potential severity of ocular injury due to these commonly used devices and reiterates a modification in design that might decrease the likelihood of accidental trauma from elastic cords.

Adult↗
PubMed1991

Echographic diagnosis of anterior hyaloidal fibrovascular proliferation.

High-resolution contact B-scan echographic imaging of the ciliary body and peripheral retina was performed on five eyes with anterior hyaloidal fibrovascular proliferation and media opacity by means of a wide (58 degrees) scanning arc. This technique determined the circumferential and anteroposterior extent of peripheral traction retinal detachment associated with anterior hyaloidal fibrovascular proliferation, which correlated highly with findings at subsequent vitrectomy. Final visual acuity of 20/400 or better was achieved in the two eyes (50%) with more limited peripheral traction detachment. In the presence of media opacity, anterior echographic imaging may allow early detection of traction retinal detachment associated with anterior hyaloidal fibrovascular proliferation and may be useful in characterizing the severity of this condition.

Adult↗
PubMed1991

A technique for facilitated visualization and dissection of the vitreous base, pars plana, and pars plicata.

We describe a technique to facilitate visualization of the vitreous base, pars plana, and pars plicata during vitreous surgery. This technique takes advantage of an externally applied fiberoptic light source coupled with scleral depression to enable direct viewing of the ciliary processes and anterior vitreous base. No special instrumentation or alteration in pars plana vitrectomy techniques is required. We have used this technique to enhance anterior dissection during vitrectomy surgery in the aphakic and pseudophakic eye associated with proliferative vitreoretinopathy, diabetic retinopathy, epithelial down-growth syndromes, and postvitrectomy fibrin formation.

Eye Diseases↗
PubMed1991

Choroidal detachment associated with malignant choroidal tumors.

The association of choroidal detachment with malignant choroidal tumors is not well recognized. The authors' experience with six cases suggests that choroidal detachment may be associated with both metastatic tumors and choroidal melanoma. In two of these cases, the choroidal or retinal detachment was so massive that echography was necessary to detect the underlying tumor. Three patients presented with painful visual loss, and three patients presented with painless visual loss or a visual field defect. In one patient, the correct diagnosis and appropriate treatment of the choroidal metastasis with external radiation relieved the patient's pain and improved visual acuity from 1/200 to 20/35. Metastatic and primary uveal malignant tumors should be added to the list of causes of choroidal detachment and can be excluded only after thorough clinical, and often echographic, examination.

Aged↗
PubMed1991

Outpatient fluid-air exchange for severe postvitrectomy diabetic vitreous hemorrhage. Long-term results and complications.

An alternative treatment to repeat vitrectomy in postvitrectomy diabetic vitreous hemorrhage (PDVH) is outpatient fluid-air exchange, but the long-term visual results of this procedure are not known. Between January 1986 and April 1989, a pars plana air-pump technique was used to perform outpatient fluid-air exchange in 20 eyes of 17 patients (17 phakic eyes) within 8 weeks of onset of PDVH. A mean follow-up interval of 78 weeks was obtained. Preoperative vitreous hemorrhage was severe enough to obscure all fundus detail (17 eyes) or produce erythroclastic glaucoma (three eyes). Initial visual acuity was hand motions or light perception in 19 eyes and improved to a median visual acuity of 20/300 soon after resolution of the intraocular air bubble. Early complications included postoperative fibrin formation (one eye) and early postoperative intraocular pressure elevation (two eyes). Recurrent vitreous hemorrhage required repeated fluid-air exchanges in seven eyes. Long-term complications included worsening of posterior subcapsular cataract (10 of 17 phakic eyes, 59%), for which cataract extraction was required in five eyes (29%). Fluid-air exchange appeared to exacerbate cataract formation, justifying a period of observation for PDVH. However, it appeared to be a low-risk alternative to repeat vitrectomy, allowing rapid visual recovery from severe PDVH.

Adult↗
PubMed1990

Comparison of xenon arc and argon laser photocoagulation in the treatment of choroidal melanomas.

We analyzed the follow-up data in 38 consecutive patients with selected choroidal melanomas that were treated by photocoagulation between 1971 and 1980. Indications for treatment included photographic documentation of tumor growth or an unequivocally positive radioactive phosphorus uptake test, or both. Xenon arc photocoagulation was used in 22 patients (58%) and argon laser was used in 16 patients (42%). At the time of data analysis, the length of follow-up was at least 58 months in all patients. Although all treated tumors were initially eradicated according to ophthalmoscopic and fluorescein angiographic criteria, there was subsequent regrowth in three of the 22 patients (14%) treated with xenon photocoagulation and in ten of the 16 patients (64%) treated with argon laser. The recurrences were observed on an average of 71 months after completion of treatment in the xenon-treated group and on an average of 30 months in the argon-treated group. More treatment sessions were required in the argon laser group to achieve tumor control. Complications of vitreous hemorrhage, cystoid macular edema, and retinal detachment were greater in the xenon photocoagulation group.

Adult↗