Biomedical subjects

M Reim

Publications and source records attributed to M Reim.

At least 55 records · Page 3Linked to original sources

PubMed1995

The relationship of macular microcirculation to visual acuity in diabetic patients.

OBJECTIVE: To assess the perifoveal microcirculation in diabetic maculopathy without clinically significant macular edema and its relationship to visual acuity. DESIGN: Prospective analysis. SETTING: A teaching hospital. PATIENTS: Fifteen patients with impaired visual acuity of 20/50 or worse, a diabetic control population with unaffected visual acuity (matched age, gender, retinopathy stage), and 52 healthy controls were enrolled. INTERVENTIONS: Study consisted of video-fluorescein angiography with image analyses and hemoglobin A1c measurements. MAIN OUTCOME MEASURES: Macular capillary blood velocity, capillary density (perifoveal intercapillary area), and foveal avascular zone. RESULTS: The capillary blood velocity was significantly reduced in both diabetic groups (P < .001) when compared with healthy controls, but did not differ significantly among the two diabetic groups. The perifoveal intercapillary area and foveal avascular zone were significantly enlarged in both diabetic groups compared with healthy controls (P < .001). The foveal avascular zone (P < .01) and perifoveal intercapillary area (P = .01) were further enlarged in the diabetics with reduced visual acuity. The visual acuity correlated significantly with foveal avascular zone (R2 = .51) and perifoveal intercapillary area (R2 = .24), indicating an association between enlargement and declined visual acuity. CONCLUSIONS: Capillary blood velocity remained unchanged regardless of presence of visual impairment, whereas foveal avascular zone and perifoveal intercapillary area indicated ischemia. This may help in defining a critical hypoxic threshold for visual loss and identifying the presence of an ischemic diabetic maculopathy.

Adult↗

PubMed1995

Conjunctival tissue examination in severe eye burns: a study with scanning electron microscopy and energy-dispersive X-ray analysis.

BACKGROUND: Long-lasting inflammation is a major problem in treatment after severe eye burns and may find expression in an altered elemental composition of the conjunctiva. Particulate contamination of biological tissue induces such inflammatory processes. In the anterior eye segment, trauma or subsequent therapy may give rise to such contamination. Scanning electron microscopy and energy-dispersive X-ray analysis are able to detect traumatic residues of submicron size and changes of the elemental composition. METHODS: Conjunctival specimens from first-time peridectomy of three healthy and nine severely burnt-eyes were examined with scanning electron microscopy and energy-dispersive X-ray analysis. The samples were prepared as cryo- or paraffin sections, mounted on carbon blocks and coated with evaporated elemental carbon. RESULTS: The samples of healthy conjunctiva showed higher concentrations of Na, P and CI. These elements showed lower concentrations in conjunctival stroma of burnt eyes excised before the 20th day after trauma than in material obtained subsequently. In two burnt conjunctival specimens there was severe traumatic contamination with Ca in Ca(OH)2 and CaO burns, and in one case the traumatic substance was Si, in a peroxide plus silicone spray burn. In the remaining six cases, particulate contamination with Fe, Al, Ni, Zn, Cu, Ti and other substances was present in the burnt conjunctivas, while no contamination was detected in the specimens of healthy conjunctivas. CONCLUSIONS: The origin of the contaminant particles is assumed to be the trauma itself and the subsequent therapy. These investigations stress the importance, for clinical purposes, or early peridectomy and contamination-free therapy.

Burns, Chemical↗

PubMed1995

Macular capillary particle velocities: a blue field and scanning laser comparison.

BACKGROUND: Two different techniques are available for measurement of macular capillary particle velocities. The psychophysical blue field simulation technique gives data on macular leukocyte flow velocities, while the scanning laser technique provides information on capillary blood velocities of hypofluorescent segments in the macular network. Published velocity data differ considerably between the two methods. The current study was undertaken to compare the two measuring techniques in a group of healthy volunteers. METHODS: Thirty-two healthy subjects (12 man, 20 women, mean age 27 years) participated in this study. All subjects underwent entoptic leukocyte visualization by means of blue field simulation followed by fluorescein angiography using scanning laser ophthalmoscopy. RESULTS: The capillary blood velocities measured using the scanning laser technique were significantly higher (P < 0.01) than the flow velocities estimated with the blue field simulation technique (2.68 +/- 0.3 mm/s vs 0.89 +/- 0.2 mm/s). No significant correlation between the flow velocities was found (r = -0.22). CONCLUSION: The differences may be related to different measuring locations and/or measurements of different phenomena. The blue field technique estimates average leukocyte flow in the macular network, whereas the scanning laser technique quantifies the velocity of erythrocyte aggregates in the capillary lumen of the para- and perifoveal network. A combination of both techniques may be helpful in interpreting physiological responsiveness and altered velocity pattern in diseased eyes.

Adult↗

PubMed1995

Explorative study of interleukin levels in the human cornea.

BACKGROUND: The presence of interleukins has been demonstrated in the cornea and other ocular tissues. Although pathogenic mechanisms are unknown, interleukins seem to be involved in inflammatory disorders of the cornea. The present study was undertaken to analyse concentrations of interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) in human corneas with various clinical diagnoses. METHODS: Immediately after keratoplasty 127 explanted human corneas with various corneal diseases were snap frozen and cryosections were prepared for histological examination. Furthermore, the protein content was measured according to the method of Bradford and the concentration of IL-1 beta and IL-6 were determined using a specific immunosorbent test (ELISA). RESULTS: It was found that IL-1 beta and IL-6 level were clearly higher in corneas with ulcerations and distinct inflammatory signs. Lower levels of both interleukins were found in corneas with a weak expression of inflammatory signs. CONCLUSIONS: Keratitis, keratoconus with inflammatory signs, and ulcerating processes showed higher interleukin levels than corneas with non-inflammatory disorders like scar formation, corneal dystrophy and keratoconus. The results could show that, depending on the clinical diagnosis, the inflammatory status of the cornea may be evaluated by the interleukin levels determined in the corneal tissue.

Cornea↗

PubMed1995

Poor prognosis of severe chemical and thermal eye burns: the need for adequate emergency care and primary prevention.

The epidemiology and wound healing following medical and surgical treatment of 101 patients with 131 severely burnt eyes due to chemical or thermal agents have been analyzed. Most of the accidents occurred at work (72.3%); the majority of the burns were chemical (84.2%), of which 79.8% were caused by alkalis. The long average duration of treatment on ward (5.2 +/- 4.1 months) and the high number of surgical interventions (8.0 +/- 8.0) indicate the difficulties in treatment and the delayed recovery of the affected eyes. Despite improved possibilities of immuno-suppression after keratoplasty (cyclosporin A) and new methods of surgery (Tenon plasty), the possibilities of an optical rehabilitation are still limited. A visual acuity of 6/60 or better was achieved in 39 eyes (32.2%). Immediate irrigation was reported in 56.1% of accidents at the place of work and in 42.8% of accidents sustained at home. There was a significant difference with respect to the extent of damage, the treatment on ward and the number of surgical interventions. The visual prognosis for eyes which received immediate irrigation was significantly improved. Eye protection was not used in any of the 101 cases. Spread of information is necessary for adequate emergency care for eye burns as well as for permanent employment of protective glasses in high-risk occupations.

Adolescent↗

PubMed1995

[Therapeutic hydrophilic bandage lenses after perforating keratoplasty in severe eye chemical burns].

BACKGROUND: The prognosis of penetrating keratoplasty after severe eye burns is uncertain. Beside of immune reactions the outcome is determined by surface problems. PATIENTS AND METHODS: Between July 1991 and October 1993 in 15 patients (16 eyes) with grade IV eye burns penetrating keratoplasties with large diameters (11-16 mm) were carried out. Cultured corneas were used with an intact epithelium. In 9 eyes hydrophilic bandage lenses (Geaflex 70, Fa. Wöhlk, Kiel) were applied initially, in the remainder 7 eyes within 7 days postoperatively. RESULTS: The lens radius best suited was found out by trial, because corneal topography was not possible for many weeks. In 12 (75%) eyes the lens had to be fitted steep, with a radius from < or = 8.7. A change in lens radius during the healing course was rare. The frequent use of artificial tear drops was important, because many eyes showed clinical manifestations of dry eye syndrome. Complications during soft contact lens wearing were rare. In 5 eyes microbiological examination was positive, but successfully treated. Under the protection of soft contact lenses 9 eyes maintained an intact epithelium. In the remainder eyes severe vascularisation with large persistent epithelial defects occurred mostly as a consequence of immune reactions. These keratoplasties developed on growth of inflammatory pannus or progressive ulceration. The average of the follow-up time was 22 months. CONCLUSION: The use of large diameter keratoplasties in combination with hydrophilic bandage lenses proved to be successful to maintain the integrity of the epithelium in these high-risk keratoplasties. The prognosis of these transplants is, however, determined by immune reactions.

Adolescent↗

PubMed1995

[Bilateral posterior ischemic optic neuritis in an adolescent with diabetes mellitus with decompensated blood glucose homeostasis].

BACKGROUND: Diabetogenic loss of visual acuity is very rare in juvenile onset diabetics. PATIENT: A 14-year-old adolescent with type-I diabetes mellitus since 7 years is reported. She experienced an episode of ketoacidotic diabetic coma after one year of very bad glycemic control. Even two weeks before onset of the diabetic coma her visual acuity decreased to 8/200 in both eyes. The perimetry revealed central and paracentral socotomas, the examination of the fundi showed only some microaneurysms and a normal optic disc. Electrophysiological results (normal ERG and EOG, pathologic pattern-VECP) proved irreversible damage of optic nerve or optic tract. RESULTS: Neuritis of optic nerve may not be existent but ischemic damage: the pattern-VECP showed no reproducible answers and the flash-VECP showed normal latency and borderline normal amplitude. There were no pathological findings in neurological and serological tests (like CT, NMR, EEG, cerebrospinal fluid, auto-antibodies or parasites). In the two years after visual loss the visual acuity increased only slightly to 13/200 in the right eye and 20/200 in the left. The optic disc showed temporal pallor in both eyes as sign of descending atrophy of the optic nerve. CONCLUSIONS: The clinical signs in this unusual case of diabetes mellitus point towards the diagnosis of a posterior ischemic optic neuropathy in both eyes caused by the extremely bad diabetic condition.

Adolescent↗

PubMed1995

[Effect of donor illness on endothelial cell number of human corneas].

BACKGROUND: In most clinical centers donor material can not be obtained in necessary amounts. Therefore corneas from long-suffering donors have to be accepted, too. It was the aim of this study to demonstrate the influence of the cause of death on the endothelial cell density of fresh human corneas. MATERIAL AND METHODS: The endothelial cell count of 81 donor corneas was determined after preparation of the corneo-scleral disc. For all donors the premortal history was evaluated concerning the cause of death and therapy. In this manner donors were divided into five groups: sudden death, carcinoma, septicemia, renal insufficiency and diabetes mellitus. RESULTS: There were no significant differences in endothelial cell count between these five groups. Even chemotherapy and radiatio of the donor had no influence on the cell density. CONCLUSION: It may be concluded, that clear corneas have a sufficient endothelial cell density and that the cause of death has no influence on this parameter. Therefore also corneas from donors with long-standing diseases may be accepted for transplantation.

Adult↗

PubMed1995

[Retinal hemodynamics in patients with hyperviscosity syndrome].

BACKGROUND: The hyperviscosity syndrome (e.g. plasmacytoma, cryoglobulinaemia and Waldenström's macroglobulinaemia) leads through the polymerisation of macro-molecules to an increased blood viscosity. This may result in microcirculatory disturbances in various organs. In the retina the hyperviscosity produces a pattern of retinal changes including dot and blot hemorrhages, retinal and optic nerve head edema and increased diameters of the veins. In the present study we quantified the retinal hemodynamic in patients with hyperviscosity syndrome. PATIENTS AND METHODS: Fifteen patients aged between 35 and 72 years were included in the study. Ten presented with Waldenström's macroglobulinaemia, two with cryoglobulinaemia and three with plasmacytoma. All patients underwent video fluorescein angiographic studies. The arteriovenous passage time (AVP) representing the retinal microcirculation and the arm retina time (ART) were quantified from the angiograms. In addition, hematocrit (Hct) and the plasma viscosity (ETA) were measured. RESULTS: The AVP was significantly prolonged in patients with hyperviscosity syndrome in comparison to healthy volunteers (AVP: 2.6 +/- 1.5 s vs. 1.6 +/- 0.4 s; p < 0.05). The ART showed no significant differences. Plasma viscosity was doubled in the patients as compared with reference values (ETA: 2.54 +/- 2.23 mPas vs. 1.24 +/- 0.08 mPas; p < 0.01). CONCLUSIONS: The simultaneous rising of plasmaviscosity and arteriovenous passage time suggests that the increase of plasmaviscosity causes retinal circulatory disturbance. All this may result in the typical fundus changes in patients with hyperviscosity syndrome.

Adult↗

PubMed1995

Macular microcirculation in cystoid maculopathy of diabetic patients.

BACKGROUND: In patients with diabetic macular oedema and central cysts ischaemia of the retina appears to be an important contributing factor in the pathogenesis of cysts. This study was performed to further elucidate the role of the inner retinal microcirculation in diabetic cystoid macular oedema (CMO). METHODS: Video fluorescein angiography allows visualisation of the macular microvasculature and measurements of the capillary blood velocity (CBV), foveal avascular zone (FAZ), and perifoveal intercapillary area (PIA, characterising capillary density). RESULTS: Twenty three diabetic subjects with CMO, matched diabetic patients without macular oedema (n = 23), and healthy subjects (n = 23) were included. CBV, PIA, and FAZ did not differ significantly among diabetic groups regardless of presence of cystoid changes. CBV was significantly reduced (p < 0.0001) and PIA was more than doubled in both diabetic groups (p < 0.0001) when compared with healthy subjects. Furthermore, FAZ showed a nearly doubled size in diabetic patients without macular oedema (p < 0.01) and a less pronounced enlargement (by 29%) in diabetics with CMO (p < 0.05). CONCLUSION: The results indicate that the retinal microcirculation in diabetic patients is markedly altered when compared with healthy subjects, regardless of CMO presence. In CMO patients the microcirculatory changes are similar to those of diabetic patients without macular oedema. Thus inner retinal perfusion does not contribute to tissue ischaemia leading to cystoid formations in diabetic maculopathy.

Adult↗

PubMed1995

Digital imaging of central serous retinopathy using infrared illumination.

When used with an infrared laser, scanning laser technology allows imaging of subretinal structures. In the indirect mode (scattered light), drusen, subretinal edema, and other changes in the retinal pigment epithelial complex can easily be visualized as pseudoprominent structures. This study was undertaken to determine the role of infrared imaging in central serous retinopathy. A total of 22 patients affected by acute central serous retinopathy were recruited for the study. All patients underwent fluorescein angiography (488 nm) and infrared imaging (788 nm) using a scanning laser ophthalmoscope (SLO 101; Rodenstock). The confocal mode was used for the fluorescein angiography, but the indirect mode was applied for infrared imaging. In all patients, serous detachment could be visualized by infrared imaging as pseudoprominent, oval-shaped structures. The size was at least one disk diameter and correspondend very well to the clinical appearance. In all patients, late-phase (20 min) fluorescein studies revealed the typical focal leakage with progressive hyperfluorescence. In six patients (27%) the extent of the serous detachment could be seen in a slightly hyperfluorescent rim. Digital image analysis showed that the extent of the serous detachment in the fluorescein angiogram was similar to the size of the thickened structures in the infrared image (r2 = 0.94). This initial study suggests that noninvasive infrared imaging can be a very useful indicator of serous detachment. Further studies regarding the influence of medical or laser treatment must be carried out to prove the clinical relevance.

Acute Disease↗

PubMed1995

Retinal hemodynamics in patients with chronic open-angle glaucoma.

Recently it has been demonstrated that retinal hemodynamics are disturbed in patients with chronic open-angle glaucoma. As the underlying cause a reduction in perfusion pressure due to increased intraocular pressure (IOP) and deficiencies of retinal autoregulation has been discussed. The present study was undertaken to clarify the influence of filtering surgery on retinal hemodynamics in patients with chronic open-angle glaucoma. A total of 17 patients with chronic open-angle glaucoma aged between 37 and 86 years were included in this prospective study. All patients underwent digital fluorescein angiography before and 10 days after fistulating procedures. From the angiograms the arteriovenous passage time (AVP) and arterial mean dye-bolus velocity (MDV) were quantified by means of digital picture analysis. At baseline the AVP was significantly prolonged in the patients as compared with reference values (AVP, 2.5 +/- 0.8 versus 1.6 +/- 0.4 s; P < 0.01). After the fistulating procedure (IOP: before, 29 +/- 5 mmHg; after, 16 +/- 4 mmHg) the AVP was significantly reduced as compared with baseline values (AVP, 2.5 +/- 0.8 versus 2.0 +/- 0.4 s; P < 0.05), whereas the MDV showed only a slight increase (MDV, 5.70 +/- 0.89 versus 5.99 +/- 0.92 mm/s; P > 0.05). This study confirms a disturbance of retinal hemodynamics in patients with chronic open-angle glaucoma. The significant reduction in AVP observed after lowering of the IOP by fistulating procedures demonstrates the positive influence of IOP reduction on the retinal circulation. The improvement in retinal circulation may prevent the occurrence of further glaucomatous damage after fistulating procedures.

Adult↗

PubMed1995

Microperimetry in patients with central serous retinopathy.

In patients with acute central serous retinopathy (CSR), evaluation of visual acuity alone may not represent visual function. In patients with acute CSR, visual function may be disturbed by localized scotomas, distortion, and waviness. For the assessment of localized light sensitivity and stability of fixation, patients with CSR were evaluated by fundus perimetry with a scanning laser ophthalmoscope (SLO 101, Rodenstock Instruments). In all, 21 patients with acute CSR and 19 healthy volunteers were included in the study. Diagnosis of CSR was established by ophthalmoscopy and digital video fluorescein angiography. All patients and volunteers underwent static suprathreshold perimetry with the SLO. Light sensitivity was quantified by presenting stimuli with different light intensities (intensity, 0-27.9 dB above background; size, Goldmann III; wavelength, 633 nm) using an automatic staircase strategy. Stimuli were presented with simultaneous real-time monitoring of the retina. Fixation stability was quantified by measuring the area encompassing 75% of all points of fixation. Light sensitivity was 18-20 dB in affected areas, whereas in healthy eyes and outside the affected area, values of 22-24 dB were obtained. Fixation stability was significantly decreased in the affected eye as compared with normal eyes (33 +/- 12 versus 21 +/- 4 min of arc; P < 0.01). Static perimetry with an SLO is a useful technique for the assessment of localized light sensitivity and fixation stability in patients with macular disease. This technique could provide helpful information in the management of CSR.

Acute Disease↗

PubMed1995

[Tenon-plasty and early keratoplasty in severe chemical eye burns].

In severe eye burns with destruction of extensive areas of the conjunctiva and epibulbar tissue, Tenon plasty has proved to be successful. Because the epithelium fails to cover the denuded stroma, the corneal surface must be protected by an artificial epithelium. If necrolysis occurs, a tectonic keratoplasty must be performed early. The clinical courses of 12 patients with 14 very severely burned eyes are reported. In addition to Tenon plasty, early penetrating keratoplasies with large diameters 10-16 mm were performed up to 3 months after the accident. The follow-up time was between 6 and 34 months (mean 15.1 months). In five cases the Tenon tissue showed marked inflammation, and the keratoplasties developed large, persistent epithelial defects and had to be covered by conjunctiva. In the other cases it was possible to preserve a healthy epithelial layer by applying soft contact lenses. In 79% of the cases an endothelial graft rejection was observed. In about 50% the transplants were lost. Early keratoplasties are mainly for tectonic repair in severely burned eyes. Optical rehabilitation was achieved in only a few cases.

Adult↗

PubMed1995

[Long-term results of Tenon-plasty in treatment of severe chemical eye burns].

From November 1986 to December 1993, 50 patients with 62 very severe eye burns were treated with Tenon plasty. Forty-one eyes showed widespread scleral ischemia, while 21 eyes had developed corneoscleral ulcerations. Surgery was done 3-126 days after the injury. A total of 210 quadrants was treated with Tenon plasty. Epithelization of the Tenon sheets was complete within 21 days in 79% and in all eyes up to 51 days. In all eyes corneoscleral ulcerations could be prevented or healed. In 48% isolated symblepharon formation or severe scarring of the fornices developed within 3 months after Tenon plasty. In these cases restoration of the conjunctiva was achieved by transplantation of autologous conjunctiva or nasal and buccal mucosa. Spontaneous epithelization of the burned cornea was achieved in 25.8%. In 36 eyes penetrating keratoplasty was performed. Sixteen (44.5%) grafts failed due to surface problems, while 12 (33.3%) grafts failed because of an endothelial immune reaction. Tenon plasty proved to be successful in preventing early necrolysis of the anterior eye segment in very severe eye burns. However, the prognosis for penetrating keratoplasty in these eyes is limited due to surface problems and immune reactions.

Adolescent↗

PubMed1995

[Foreign body reaction after lens implantation. Correlation between visual acuity and density of giant cells].

In the early postoperative stage giant cells often appear on IOLs. Independent of this, a foreign-body reaction may start about 3 months after surgery from posterior synechia. Foreign-body reaction occur more frequently in diabetic patients or patients with glaucoma. In a prospective trial, we examined the surface of the IOLs from 115 patients with diabetes or glaucoma using specular microscopy. We compared the maximal density of the cells to visual acuity. One week and 1 month after surgery, the maximal density of giant cells was between 0 und 20/mm2; vision (median) was independent of the giant cell density in all groups between 20/25 and 20/30. Three months after surgery, the maximal density of giant cells was between 0 und 35/mm2; vision (median) was 20/25 in patients with no giant cells or cell densities up to 15/mm2. Seven patients had cell densities between 16 and 35/mm2; visual acuity (median) was 20/125. The difference was significance was (P < or = 0.05). Six months and 1 year later after surgery, the maximal density of giant cells was between 0 and 41/mm2; the vision (median) in patients with giant cell densities up to 15/mm2 was between 20/20 and 20/25. In five examinations the cell densities were found to be in the range of 16 to 40/mm2; visual acuity (median) was 20/80 in these cases. The difference is not significant (P < or = 0.05). A foreign-body reaction with more than 15 giant cells/mm2 is a rare complication of cataract surgery with lens implantation. Three months after surgery, this complication correlates with poor vision.

Aged↗

PubMed1995

Quantification of cystoid changes in diabetic maculopathy.

PURPOSE: In patients with diabetic macular edema and cysts, quantification of the extent of the cystoid formation has been difficult. This study was performed to introduce reliable measurements of cysts, the quantification of the extent, and its relation to visual acuity. METHODS: Fluorescein angiography generated with a scanning laser ophthalmoscope provided detailed recognition not only of the foveal microvasculature, but also of well-demarcated cystoid formations in the early phases. The sampling area included the central 2.5 degrees of the fovea. Using digital image analysis, two independent observers estimated the area covered by cysts, the number of cysts, and the foveal avascular zone (FAZ). RESULTS: Twenty-three subjects with diabetes and macular cysts were enrolled in the current study. The mean area of the cysts was 0.315 +/- 0.241 mm2 (0.05 mm2 to 0.9 mm2), and the number of cysts ranged from 1 to 7. Both parameters, area of cysts (r2 = 0.61), and number of cysts (r2 = 0.48) showed a significant correlation with visual acuity (P < 0.01), whereas FAZ (0.08 to 0.58 mm2) showed no significant correlation with visual acuity. CONCLUSIONS: Fluorescein angiography allows a reproducible quantification of the extent of macular cysts. The relation of visual acuity to the number of cysts and to the area covered by the cystoid formation is highly significant. Thus, both these measures can provide an objective criterion for the estimation of visual prognosis and an outcome for evaluation therapy techniques.

Adult↗

PubMed1995

Remarks on the vitality of the human cornea after organ culture.

The purpose of this study was to obtain further information on the viability of organ-cultured human cornea. We thus used a specific staining method for succinate dehydrogenase (SDH), which is located in the membrane system of vital mitochondria. We examined fresh and long-term-cultured human corneas. After an initial incubation period in dextran-free culture medium, corneas were stored in a medium containing dextran. With respect to different appearances of the SDH staining, minimal essential medium without dextran seems to have a positive effect on the condition of epithelial cells. After renewal of the medium, keratocytes showed a brief improvement followed by a delayed deterioration, while the endothelial cells were severely damaged. However, best results for all three cell types were observed on the fourth day in a medium containing dextran. We therefore conclude that these corneas were best suited for transplantation.

Adolescent↗