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Biomedical subjects

K Lucke

Publications and source records attributed to K Lucke.

At least 19 recordsLinked to original sources
PubMed2002

Clinicopathologic correlation in hemorrhagic age-related macular degeneration.

PURPOSE: To analyze and compare the histopathology of surgically extracted membranes in hemorrhagic age-related macular degeneration (AMD) versus extracted classic, mixed and occult choroidal neovascularization (CNV) in AMD. METHODS: Thirty consecutive membranes, surgically removed in hemorrhagic AMD, were analyzed and compared with consecutive series of 50 classic, 20 mixed and 20 occult membrane specimens in exudative AMD. The specimens were serially sectioned and stained in a stepped fashion with hematoxylin-eosin, Masson trichrome and periodic acid-Schiff stain. RESULTS: Diffuse drusen were observed in all hemorrhagic AMD specimens, fibrovascular tissue was found in 29 of 30 specimens which was located subretinally in 11 specimens and/or in Bruch's membrane in 28 specimens. A hemorrhage was located subretinally in 21 specimens, in the stroma of the fibrovascular tissue in 17 specimens, at the choroidal side of the diffuse drusen adjacent to fibrovascular tissue in 13 specimens and at the choroidal side of the fibrovascular tissue in Bruch's membrane in 8 specimens. Grossly dilated thin-walled vessels were identified in one hemorrhagic AMD case, suggestive of polypoidal choroidal vasculopathy. Scarred tears of the retinal pigment epithelium were identified in two specimens. CONCLUSION: A large spectrum of histo-architectural lesions is recognized in hemorrhagic maculopathy. Hemorrhages do not only characteristically appear in the subretinal space or in the stroma of the neovascular tissue but also at the choroidal side of the diffuse drusen adjacent to the neovascular complex and at the choroidal side of the intra-Bruch's fibrovascular tissue.

Humans↗
PubMed1997

Peripheral visual field loss after vitreous surgery for macular holes.

BACKGROUND: Vitreous surgery for Idiopathic macular holes can result in both anatomic closure of the hole and visual improvement. In some patients even normal visual acuity is achieved. Postoperative visual field loss is a newly recognized complication. This prospective study evaluates the frequency and significance of scotomas after vitrectomy with gas tamponade for stage I-IV macular holes. METHODS: Over a period of 10 months, a consecutive series of 30 patients and 31 eyes with macular holes underwent pre- and postoperative automatic perimetry (Octopus 07, 70 degrees) and macular perimetry (Octopus M1, 24 degrees) to characterize the pattern of visual field defects after vitrectomy with gas tamponade. Success rates were evaluated and complications were analyzed. RESULTS: Anatomic success after one surgical procedure was achieved in 85% of cases, visual improvement in 58%. Some 70.1% of patients had peripheral scotomas postoperatively; some of these were highly symptomatic and others were detected by visual field testing only. The most consistently affected areas were the temporal and lower periphery of the visual field. The central visual field, however, was not disturbed. CONCLUSION: Visual field loss after otherwise successful surgery for macular holes is an unexpectedly frequent and serious complication. The authors discuss various factors that may contribute to the postoperative scotomas. From the localization of the scotomas it seems most likely that they are caused by the persistent pressure of the gas bubble on the peripheral retina. Further investigations are necessary to confirm this hypothesis, and ways must be found to avoid this complication in order to be able to proceed with this otherwise promising new indication group for vitreous surgery.

Aged↗
PubMed1995

[Experimental studies of the risks of endocapsular polymerization of injectable intraocular lenses].

Various experimental lens refilling procedures have been proposed. One of these methods uses endocapsular polymerization of the injected material by light exposure. In this study we wanted to characterize the potential risks of this procedure due to light and temperature hazards. We performed in vitro experiments on enucleated pig eyes and an in vivo study on 15 rabbits. During the polymerization process the highest temperature recorded (45.1 degrees C) was measured at the posterior lens capsule for a few seconds. The measured irradiance (0.065 W/cm2) and the risk of photochemical damage to the retina during 20 s of polymerization was comparable to that caused by 1.5 min of standard coaxial illumination with our operating microscope. In vivo we found no serious inflammatory reactions except for four cases where surgical problems had occurred. No direct retinal damage could be detected histopathologically. In conclusion, we think that lens refilling and endocapsular polymerization are promising techniques. However, refilling materials with better physical properties than those available so far need to be developed.

Acrylates↗
PubMed1995

Vitreoretinal surgery in advanced Coat's disease.

Massive subretinal exudates as well as vitreal traction often induce complicated retinal detachments in patients with advanced Coats' disease. If left untreated, most patients experience secondary glaucoma by rubeosis and phthisis bulbi in addition to irreversible visual loss. We report on the surgical procedures used and results obtained in three patients aged between 21 and 28 years with combined exudative and traction-induced detachment. In all cases, extensive but unsuccessful retinal coagulation had been performed. The surgical intervention was done by application of an encircling buckle followed by vitrectomy and removal of preretinal membranes and subretinal lipid exudates via retinectomies. Particular attention was paid to the intensive endodiathermy of retinal teleangiectasies during surgery. Surgery was concluded by siliconeoil tamponade. Postoperatively, progressive resorption of remaining exudates and teleangiectatic vessels could be observed. All patients demonstrated stable functional and anatomic results at the last follow-up examination performed at 13 months to 6 years after surgery. A stabilization of the anatomic and functional situation can be achieved even in advanced cases of Coats'-induced traction retinal detachment by vitreoretinal surgery.

Adult↗
PubMed1995

[Endotamponade with silicon oil in severe proliferative retinopathy with attached retina].

Silicone oil as endotamponade in cases with attached retina is only indicated in a few very selected cases. These are cases with a high risk of intravitreal hemorrhage and a need for quick visual rehabilitation. We examined 23 patients, who had undergone pars plana vitrectomy and silicone oil filling. All patients were diabetics with proliferative retinopathy and recurrent intravitreal hemorrhage. In 14 cases it was the only eye; 11 eyes previously had a vitrectomy. We analyzed these cases for visual acuity, rubeosis, bleeding tendency, reproliferations, cataract development and glaucoma. The follow-up time was 32 months. In 22 of 23 eyes quick visual rehabilitation was achieved, and the patients had at least ambulatory vision within the first week. In one case poor visual acuity was due to exudative maculopathy. No relevant bleeding occurred. In 14 of 16 phacic patients we observed a cataract. Seven patients developed glaucoma, which was due to neovascularization in 5 cases. It was successfully treated in all cases and no visual loss occurred. In 5 cases we observed a peripheral traction retinal detachment, in one case a traction retinal detachment at the posterior pole. In selected cases silicone oil can prevent recurrent intravitreal hemorrhage, allowing rapid visual recovery. Considering the complications, the silicone oil should be removed as soon as possible.

Diabetic Retinopathy↗
PubMed1994

Lens refilling and endocapsular polymerization of an injectable intraocular lens: in vitro and in vivo study of potential risks and benefits.

Endocapsular cataract removal and injection of a liquid artificial lens has several advantages, including restitution of accommodation, small corneoscleral incision, a more physiological position of the intraocular lens, and a reduced rate of secondary opacification. Our technique consists of bimanual phacofragmentation followed by injection of a fluid monomeric material that can be polymerized inside the capsular bag by short light exposure. Our study assessed the potential risks of the technique (e.g., heat damage to ocular tissue, light damage to the retina) and investigated the technique in vivo. We performed in vitro experiments on porcine cadaver eyes and an in vivo study on 15 rabbits. After a clinical follow-up of at least 12 weeks, the eyes were investigated histopathologically. During the polymerization process, the highest temperature measured at the posterior lens capsule was 45.1 degrees Celsius for a few seconds. The measured irradiance (0.065 watts per cm2) and the risk of photochemical damage to the retina during 20 seconds of polymerization were comparable to that caused by 1.5 minutes of standard coaxial illumination with the operating microscope. In vivo there were no serious inflammatory reactions except in four cases in which there had been intraoperative problems. The rate of secondary opacification appeared less than in conventional intraocular lens implantation in rabbits, especially when the capsule refilled completely. Retinal damage could not be detected histopathologically. In conclusion, refilling techniques may be successful once appropriate refilling materials become available.

Animals↗
PubMed1994

[Clinical heterogeneity of non-Hodgkin's lymphoma of the eye with extraocular manifestations].

Primary, ocular Non-Hodgkin lymphoma is a multicentric disease. The prognosis is mostly determined by involvement of the central nervous system and/or visceral organs. Since ocular symptoms often precede accompanying manifestations and since the eye is easily accessible to diagnostic measures, the ophthalmological diagnosis is essential for early detection and treatment of this complex disease, which has a poor prognosis. To illustrate the extraordinary heterogeneity of the clinical symptoms, four case reports have been selected which demonstrate various ocular symptoms and extraocular localizations. The ophthalmological variability ranges from typical uveitis to retinitis and vasculitis with varying symptoms during the progression of the disease. Completely different extraocular features were induced by long-standing, local infiltrates within basal ganglia, a diffuse infiltration of the brain leading to an acute increase in intracranial pressure, a peripheral tumour within the spinal channel or massive infiltrates of liver, lung and kidneys. Lack of pathognomonic features, high clinical variability and the limited value of imaging techniques and histopathological measures often lead to serious delays in diagnosis.

Aged↗
PubMed1993

[Silicone oil in surgery of complicated retinal detachment].

Silicone oil has established itself as an internal tamponade in the treatment of complicated retinal detachments. The most common indications are PVR, advanced proliferative diabetic retinopathy, giant tears and severe trauma to the posterior segment of the eye. Other rarer indications have meanwhile been added. By its use success rates can be achieved that were thought impossible only ten years ago. Serious complications such as secondary glaucoma and keratopathy, much dreaded in the early years of its use, are better understood and are generally not considered contraindications anymore. Secondary glaucoma occurs in about 20% of eyes, has a wide variety of causes and is rarely attributable to the silicone oil itself, provided purified and highly viscous oil is used. The development of keratopathies has been greatly reduced by the introduction of the Andoiridectomy and this complication is now largely confined to eyes with severe trauma, hypotony or aniridia. Toxic effects of silicone oil have so far not been convincingly demonstrated. Whereas similar results can be obtained by the use of long-acting intraocular gases in milder cases of the conditions described, silicone oil tamponade has proved to be an effective treatment in the more advanced forms of complicated retinal detachments.

Diabetic Retinopathy↗
PubMed1992

Acute onset of rubeosis iridis after diabetic vitrectomy can indicate peripheral traction retinal detachment.

Acute onset or exacerbation of rubeosis iridis associated with peripheral retinal detachment after vitrectomy represents a rare but serious complication of advanced diabetic retinopathy that indicates a poor prognosis. The clinical features, surgical procedures, and anatomical and functional results for a series of 13 eyes presenting with this complication are reported. In addition to rubeosis iridis and peripheral retinal detachment, anterior hyaloidal fibrovascular proliferation (APH) was also present in 10 eyes. All eyes had undergone one or more previous vitrectomies for diabetic complications such as nonclearing vitreous hemorrhage and traction retinal detachment. Treatment modalities for iris neovascularization and peripheral retinal detachment included reattachment procedures with an encircling band, peripheral membrane peeling, and, if necessary, peripheral retinectomy. Peripheral coagulation therapy was performed in all eyes. Eight eyes received an intraocular silicone-oil tamponade. Early results (4 weeks post-surgery) showed regression or stabilization of rubeosis iridis in all eyes. Later results (mean, 9 months post-surgery) revealed nine eyes with stabilized anterior ocular neovascularization and reattachment of the retina. Four eyes were anatomic failures due to recurrent rubeosis iridis/AHP or traction retinal detachment, and three of them also developed ocular hypotony. None of the eyes has thus far been lost as a result of neovascular glaucoma or painful phthisis. Ambulatory vision was retained in ten eyes, but function was limited to a low level as a result of the underlying ischemic disease. Immediate reattachment surgery in combination with anterior/peripheral coagulation therapy was shown to be an effective measure for controlling iris neovascular activity in eyes afflicted with acute anterior ocular neovascularization.

Acute Disease↗
PubMed1992

A method of lens extraction for the injection of liquid intraocular lenses.

A method for the injection of liquid intraocular lenses into the capsular bag would offer many benefits in the treatment of cataracts. The corneoscleral incision could be made even smaller, the lens diaphragm would be conserved more physiologically, and a method of therapy for presbyopia might eventually be possible. As a prerequisite, a method of endocapsular lens removal is needed. We have developed such a method for our experiments on the injection of liquid intraocular lenses in the enucleated pig eye. We use a bimanual technique through two opposing 1-mm corneoscleral incisions and two openings measuring 1 mm in diameter in the peripheral anterior capsule. By using curved needles and suction tips, we could remove the capsular contents completely. The injected material was polymerized in situ by exposure to blue light and resulted in an optically clear cast of the lens capsule of surprisingly good optical quality.

Animals↗
PubMed1992

Light-induced endocapsular polymerization of injectable lens refilling materials.

The use of advanced phacoemulsification techniques enables the surgeon to remove opacified lens material while preserving a nearly complete capsular bag. For this reason, several groups are presently working on lens refilling techniques. We have developed a method for the injection of a liquid monomer into the lens capsule. The material can be polymerized by exposure to cold light (wavelength, 400-500 nm) within the capsular bag. Using cell-culture experiments, we selected an optically clear material that has cytotoxic properties when placed in direct contact with cells but does not release cytotoxic substances into the surrounding medium. We have shown that reflux of the liquid monomer into the anterior chamber can be avoided by using a material that can be polymerized within the capsule. Initial experiments in rabbits indicate that the technique can be used without inducing a significant postoperative inflammatory response or leading to morphological changes in the cornea or the retina.

Animals↗
PubMed1992

[Removal of silicone oil in treatment of so-called emulsification glaucoma].

We investigated whether emulsification glaucoma after silicone oil implantation can be influenced positively by removal of the oil. In 16 of 264 patients successfully operated upon with purified silicone oil 5000 cps, we found a glaucoma refractory to medical therapy and probably caused by emulsification. We removed the silicone oil from these eyes and followed them up for a period of 6 months (12.5 +/- 7.3 months). In 12 of the 16 eyes, the intraocular pressures were normalized after silicone oil removal with or without antiglaucomatous therapy. Four eyes showed raised intraocular pressures in spite of silicone oil removal. These could, however, be largely explained by neovascularization or chronic inflammation with increasing anterior synechia formation. In eyes with possible emulsification glaucoma, early and thorough removal of the silicone oil is therefore recommended since this can result in normalization of intraocular pressures in a large percentage of cases.

Glaucoma↗
PubMed1991

[Fluorescein angiography findings after retinotomy and retinectomy].

Drainage-retinotomies and relaxing retinectomies are helpful techniques in extreme vitreoretinal surgery. They have become established as a surgical instrument, but their possible pathophysiologic effects on the retina, pigment epithelium and choroid have not been investigated as yet. 30 Patients with retinotomies or retinectomies after vitrectomy with silicone oil filling for advanced proliferative vitreoretinopathy were studied angiographically. Fluorescein angiographic findings revealed 1. a predominant effect of endophotocoagulation in the area of the retinotomy/retinectomy with occlusion of the choriocapillaris and hyperpigmentation and window effects of the retinal pigment epithelium, but sometimes there was a localized traction effect with retinal and choroidal folds, 2. that retinal perfusion is unaffected in untreated and coagulated areas without evidence for a breakdown of the blood-retina-barrier or retinal ischemia, 3. an intact blood-retinal-barrier in areas of uncovered retinal pigment epithelium, 4. no evidence for significant reproliferations in the areas of retinotomies and retinectomies, 5. choroidal neovascular membranes which may occur postoperatively at the retinotomy site probably as a complication for intraoperative injury of Bruch's membrane, 6. a cystoid macular edema, an optic atrophy, pigment-fallout, depigmented tracks and choroidal folds as unspecific findings post retinal detachment surgery. The angiographic data support the clinical impression, that retinotomies and retinectomies performed in otherwise untreatable cases cause no significant damage in the attached retina.

Drainage↗
PubMed1991

[Visual outcome after silicon oil surgery].

The question as to whether silicone oil is toxic to the retina has not been resolved to this day. We have attempted to find evidence of retinal toxicity by studying the development of visual acuity in eyes operated on with silicone oil. We selected these eyes from a cohort of about 500 that had attached retina, no glaucoma and no keratopathy. The average visual acuity increased continuously over 2 years if all extraretinal factors influencing visual acuity are excluded. Although in eyes from which silicone oil had been removed visual function developed better than in those in which it remained indefinitely, this could not be attributed to a toxic effect of silicone oil, since the difference was apparent even while eyes in both cohorts where still filled with oil. The difference is more probably a result of patient selection. In individual cases in which silicone oil was not removed for up to 8 years the visual acuity remained stable. An analysis of the patients with loss of vision despite attached retinas yielded causes that were essentially specific to the underlying disease. We found no clinical evidence suggestive of a toxic effect of silicone oil.

Follow-Up Studies↗
PubMed1991

[Pars plana capsule resection for therapy of ocular hypotension syndrome caused by capsule shrinkage with ciliary body detachment].

A rare complication of extracapsular cataract extraction is hypotony due to capsular shrinkage, with consequent ciliary body detachment. A classic hypotony syndrome with progressive loss of visual acuity was observed in two patients, one with extracapsular aphakia and one with extracapsular pseudophakia. Each presented with a fibrotic, shrunken capsular bag and a secondary cataract. As the contraction forces appeared to derive predominantly from the periphery of a circumferentially fibrotic capsular bag, the lens capsule was operatively removed. A pars plana approach was used to access the equatorial capsular ring and visualize the ciliary body processes. The intraocular lens appeared to be stable and remained in situ. Postoperative elevation of intraocular pressure occurred, with improvement of hypotony symptoms, especially in the fundus. Visual acuity also improved, but was limited due to secondary cystoid edema.

Adult↗
PubMed1990

[Secondary glaucoma after silicone oil surgery].

In spite of advances in surgical technique and the development of purified silicone oils, secondary glaucoma still develops in 10-20% of cases following silicone oil surgery. In the first part of this study it is shown by life-table analysis that factors such as early lens removal, inferior iridectomy, early silicone removal or the use of purified silicone oil have little or no influence on the development of glaucoma. In the second part an attempt is made to pinpoint possible causes of secondary glaucoma by re-examining all cases in which elevated intraocular pressure developed some time after silicone oil surgery. It was found that a multitude of factors (e.g., inflammation, angle-block, anterior peripheral synechiae and emulsification) were involved in the pathogenesis of temporary or persistent secondary glaucomas. In most cases pre-existing pathology was found to be responsible rather than the silicone oil itself. The majority of the cases in which the silicone oil caused secondary glaucoma by emulsification responded well to medication alone or removal of the silicone oil.

Aphakia↗
PubMed1990

[Results after retinotomy and retinectomy in the treatment of complicated retinal detachment].

Of 241 cases operated with pars-plana vitrectomy and silicone oil filling for complicated retinal detachment we performed retinotomies for drainage of subretinal fluid or removal of subretinal strands in 48 cases (20%) and retinectomies for relief of traction in 80 cases (33%). We found no negative influence of these retinotomies and retinectomies on the anatomic or functional outcome in our major indication groups--PVR, PDR and perforating injury. With increasing size of the retinectomy the anatomic success rate fell from 100% in cases with a 90 degrees retinectomy to 76% with a retinectomy larger than 270 degrees. In 21 out of 80 cases traction relief was insufficient so that we had to enlarge the retinectomy. 17 of these 21 cases could then be attached permanently.

Diabetic Retinopathy↗