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Biomedical subjects

A Remky

Publications and source records attributed to A Remky.

69 records · Page 4Linked to original sources
PubMed1994

Hemodilution therapy in central retinal vein occlusion. One-year results of a prospective randomized study.

Systemic hemorheologic abnormalities may play a part in the pathogenesis of central retinal vein occlusions. A statistically significant elevation of plasma viscosity was found in patients with acute central retinal vein occlusion compared with control patients. Local retinal blood flow parameters including arteriovenous passage time and mean arterial dye bolus velocity were significantly altered in the central retinal vein occlusion patients compared with age-matched controls at baseline examination. We performed a randomized, prospective, single-blind clinical investigation to determine the effect of hemorheological manipulation on the clinical course and retinal blood flow of eyes with central vein occlusion. Hemodilution included plasma expansion with hydroxyethyl-starch, withdrawal of whole blood if the hematocrit was above 42%, and rheologic manipulation with parenteral pentoxifylline. We found a statistically significant improvement in visual acuity at 1 year post-treatment for the treated group compared with the control group (increase of visual acuity of 1.5 lines vs decrease of 1.5 lines). The retinal blood flow parameters were markedly improved soon after the institution of therapy, and this may have contributed to the improvement in visual acuity in the treated group. There was no statistically significant difference between the two groups in the progression to ischemic central vein occlusion.

Aged↗
PubMed1994

Perifoveal microcirculation with non-insulin-dependent diabetes mellitus.

Fluorescein angiograms were performed to evaluate perifoveal capillary blood velocities (v), capillary density (perifoveal intercapillary areas: PIA) and the foveal avascular zone (FAZ) by means of the scanning laser technique (SLO-101 Rodenstock). The angiograms were digitally stored and the data quantified off-line with an image analyzing system (IBAS). In the present study 46 patients with non-insulin-dependent diabetes mellitus (NIDDM) were examined and their data compared with that of 31 healthy volunteers. The perifoveal capillary flow velocity of the NIDDM subjects (v = 2.33 +/- 0.36 mm/s) was significantly (P < 0.01) decreased as compared to healthy subjects (v = 2.86 +/- 0.41 mm/s). The perifoveal intercapillary areas in the foveal avascular zone were significantly increased in patients with NIDDM (PIA = 10029 +/- 3402 microns2; FAZ = 0.415 +/- 0.272 mm2) as compared with healthy subjects (PIA = 3965 +/- 467 microns2; FAZ = 0.221 +/- 0.071 mm2). These data suggest the possibility that a decrease in perifoveal capillary blood velocities in combination with decreased capillary density (enlarged PIA) and an enlargement of the foveal avascular zone may occur in patients with NIDDM. The determination of these parameters could help in monitoring the progress of diabetic retinopathy and diabetic maculopathy.

Adult↗
PubMed1994

[Effect of hemodilution on retinal hemodynamics in retinal branch vein occlusion].

The aim of hemodilution therapy in branch retinal vein occlusion is to lower the hematocrit (HCT) and plasma viscosity and thus to ameliorate perfusion of the affected areas. In this study we compared the influence of hemodilution therapy on the retinal hemodynamics of affected areas with unaffected areas. Thirty patients with branch vein occlusion (duration of symptoms less than 14 days) aged 40-84 years (mean 63 +/- 11 years) were examined. All patients received iso- (HCT > or = 42%) or hypervolemic (HCT < 42%) hemodilution with hydroxyethyl-starch (MW 200,000/0.5 10%, HAES-steril) for 10 days. Retinal hemodynamics were quantified by means of video fluorescein angiography assessing arteriovenous passage time (AVP) of the affected and unaffected branches. Hemodilution resulted in a significant decrease in hematocrit, plasma viscosity and erythrocyte aggregation. The arteriovenous passage time of the affected area improved significantly (before therapy 4.91 +/- 2.2 s, after therapy 3.9 +/- 1.6 s). The unaffected branch showed no significant change in the arteriovenous passage time (1.85 +/- 0.7 s before and 1.79 +/- 0.7 s after therapy). The decrease in AVP in the affected branch indicates ameliorated perfusion in the affected branch area without changing the retinal hemodynamics in unaffected areas.

Adult↗
PubMed1994

Indocyanine green video angiography in patients with age-related maculopathy-related retinal pigment epithelial detachments.

Previous studies have stressed the benefit of laser photocoagulation for patients with age-related macular degeneration (AMD) and well-defined subretinal neovascularization (SRN). However, such lesions account for only 30% of cases with exudative age-related maculopathy. Especially in patients with retinal pigment epithelial detachment (PED), SRN is usually occult. This study was performed to reveal the role of digital indocyanine green (ICG) video angiography in the diagnosis of SRN in patients with PED. A total of 34 patients with AMD-associated retinal PED participated in the current study and underwent fluorescein and ICG angiography using scanning laser ophthalmoscopy. In these patients fluorescein angiography revealed no distinct SRN, whereas in 21 eyes (62%) ICG angiography showed well-demarcated choroidal neovascularization. The present study demonstrates that SRN can be detected in more than 50% of patients with PED by means of ICG video angiography. Therefore, ICG video angiography improves the detection of SRN in patients with AMD-associated PED.

Aged↗
PubMed1994

[Anticardiolipin antibodies in vascular occlusions of the eye].

Elevated levels of anticardiolipin antibodies (ACA) have recently been found to be associated with occlusive diseases such as myocardial or cerebral infarction or venous thrombosis. In a prospective study anticardiolipin antibodies (both IgG and IgM) were measured by ELISA in 140 patients with acute vascular occlusions of the eye. Patients with clinical evidence for lupus erythematodes, HIV infection or elevated concentrations of antinuclear antibodies (IIFT with HEp-2 as antigen, LD Diagnostika, Heiden, FRG) were excluded. Elevated concentrations of IgG-ACA and IgM-ACA were found in 9% of the cases, with no correlation with the type of ocular vascular occlusion (retinal artery occlusion, retinal vein occlusion, anterior ischemic optic neuropathy). These results indicate that the anticardiolipin syndrome with elevated concentration of anticardiolipin antibodies may also have a causal role in some patients with occlusive eye diseases, whereas in most patients the concentrations were within normal ranges.

Adult↗
PubMed1994

[Follow-up of arteriosclerosis-induced anterior ischemic optic neuropathy].

In 22 patients with acute arteriosclerotic anterior ischemic optic neuropathy (AION), examinations were conducted before the start of therapy and between 1 and 3 years later. In the acute stage of the disease the patients were treated with hemodilution for 10 days. The visual acuity improved from 0.2 to 0.4 (median). Compared with the visual acuity before therapy, at the follow-up 1-3 years later visual acuity had improved by 3 lines or more in 11 patients, remained stationary in 9 patients (+/- 1 line), and worsened in 2 patients by 3 lines or more. The visual fields (Goldmann) improved in 8 patients, did not change in 10 patients and worsened in 4 patients. After 1-3 years, 14 patients (64%) showed a sectorial pallor and 8 patients (36%) a diffuse pallor of the optic disc. Videofluorescein angiography revealed hypofluorescent discs in all patients. No difference in arm-retina time (ART) was found between the acute phase (13.0 +/- 3.3 s) and the examination 1-3 years later (13.1 +/- 2.2 s). ART was within normal limits in all patients. The arteriovenous passage time (AVP) dropped significantly, from 2.36 (+/- 0.81) s in the acute phase to 1.91 (+/- 0.56) s 1-3 years later. However, the AVP still did not fall to normal levels (1.45 +/- 0.40 s). Slowed retinal hemodynamics (AVP) with normal ART at the same time suggests a disturbance in microcirculation still present 1-3 years after the acute phase of AION. The rheological parameters (hematocrit, plasma viscosity, erythrocyte aggregation index) did not show any change between examinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Retinal hemodynamics in patients with arterial hypertension].

Arterial hypertension is a risk factor for the development of retinal, cerebral and renal microangiopathy. Therefore, a prospective study was started to investigate the progression of retinal microangiopathy in hypertensive patients. Initially, 254 patients were examined in a cross-sectional study. Following an ophthalmological examination, retinal hemodynamics were quantified by means of video-fluorescence angiography. Moreover, blood fluidity (hematocrit, plasma viscosity and erythrocyte aggregation) was analyzed. The severity of the retinal changes was defined according to the Neubauer classification. One hundred (40%) patients showed retinal changes corresponding to stage I; 133 (52%) were classified as stage II. Hypertensive retinopathy (stage III and IV) was encountered in 20 (8%) patients. Arm-retina time was significant prolonged among the hypertensive patients compared with a control group. Arteriovenous passage time showed no significant differences between hypertensive patients and reference values. Plasma viscosity was significantly increased in hypertensive patients and showed a significant increase with progression of the retinal changes. Hematocrit and erythrocyte aggregation were normal among the patients studied. The present findings show an alteration in blood fluidity among hypertensive patients, whereas retinal microcirculation showed no significant disturbances. Follow-up studies are planned to assess the development of retinal microcirculatory changes among hypertensive patients.

Adult↗
PubMedDate not supplied

[Retinal vessels before and after photocoagulation in diabetic retinopathy. Determining the diameter using digitized color fundus slides].

BACKGROUND: Retinal vessel diameter is an important parameter in blood flow analysis. Despite modern digital image technology, most clinical studies investigate diameters subjectively using projected fundus slides or negatives. In the present study we used a technique to examine vessel diameters by digital image analysis of color fundus slides. We investigated in a retrospective manner diameter changes in twenty diabetic patients before and after panretinal laser coagulation. MATERIAL AND METHODS: Color fundus slides were digitized by a new high resolution scanning device. The resulting images consisted in three channels (red, green, blue). Since vessel contrast was the highest in the green channel, we assessed grey value profiles perpendicular to the vessels in the green channel. Diameters were measured at the half-height of the profile. RESULTS: After panretinal laser coagulation, average venous diameter was decreased, whereas arterial diameter remained unchanged. There was no significant relation between the diameter change and the number of laser burns or the presence of neovascularization. CONCLUSIONS: Splitting digitized images into color planes enables objective measurements of retinal diameters in conventional color slides.

Adult↗
PubMedDate not supplied

[Fluorescence angiography of the anterior eye segment in severe eye chemical burns].

BACKGROUND: Severe eye burns usually result in extensive necrosis of the conjunctiva and subconjunctival tissue. To reduce the reactive inflammatory response excision of the necrotic tissue is necessary. PATIENTS AND METHOD: Between August 1990 and December 1994 fluorescein angiograms of the anterior eye segment were performed in 13 (17 eyes) patients with most severe eye burns. The angiographies were carried out 1-4 days after the accident. Conventional photo angiography was performed using a fundus camera (NF 505-AF Nikon). RESULTS: The angiograms revealed characteristic patterns that provided exact information on the perfusion of burned conjunctival and underlying tissue. It was particularly useful in the detection of clinically not recognisable subconjunctival ischemia. In addition, perfusion of the episcleral vessels and the extent of scleral ischemia could be quantified. According to the angiographic findings subtile excision of the necrotic tissue was performed and vascularized tissue was preserved. CONCLUSION: Anterior segment angiography is a valuable method in assessing the extent of necrosis of the conjunctiva and underlying tissue and in determining scleral ischemia. It provides a basis for deciding the extent of surgical debridement of necrotic tissue in the acute phase of the burn. The quantification of limbal and scleral ischemia may give useful information for early plastic-reconstructive procedures.

Adult↗
PubMedDate not supplied

[Digital fluorescein angiography in follow-up of the clinical course in therapy of patients with central vein occlusion and cystoid macular edema].

BACKGROUND: Fluorescein angiography with a scanning laser ophthalmoscope allows the quantification of morphologic and dynamic changes in the retina. In two patients with central retinal vein occlusion we monitored the progression of the cystoid macular edema (CME) and changes of microcirculation with a follow up of 4 to 6 months. MATERIALS AND METHODS: Two patients with central retinal vein occlusion and CME were examined by means of digital fluorescein angiography. Arteriovenous passage times and macular capillary blood velocities in combination with quantifications of the macular angioarchitecture and the extent of the CME were evaluated. RESULTS: Hemodilution therapy improved retinal circulation, whereas macular circulation and the severity of the CME remained unchanged. With persisting CME oral acetazolamid therapy was initiated. Oral Acetazolamide led to resorption of the cystoid edema in tandem with improved macular circulation. The capillary density was altered but remained unchanged over time. CONCLUSIONS: By means of digital analysis of fluorescein angiograms a detailed monitoring and retinal and macular dynamics, macular morphology is possible. In these two cases CME improved after Acetazolamide and moreover retinal circulation returned to normal conditions.

Acetazolamide↗
PubMedDate not supplied

Levocabastine eye drops do not affect accommodative capacity in volunteers and intraocular pressure in glaucoma patients.

Levocabastine is a potent and highly selective H1-receptor antagonist specifically developed for the topical treatment of allergic conjunctivitis. This study assessed the effects of levocabastine eye drops on accommodative capacity in 20 healthy volunteers and on parameters influencing glaucoma in 12 glaucoma patients. A single dose of levocabastine (0.5 mg/ml) did not influence accommodative capacity, pupil diameter, or intraocular pressure (IOP) in volunteers. Similarly, levocabastine (0.5 mg/ml, one drop in each eye twice daily) for two weeks was well tolerated by patients with glaucoma. Measurement of IOP, iridocorneal angle, depth of the anterior chamber, visual acuity and near-point in these patients provided no evidence of exacerbation of glaucoma or interactions with concurrent antiglaucoma medication. Application site reactions (local irritation and ocular pain) were the only adverse effects, with an incidence comparable to placebo-treated controls. In conclusion, ocular levocabastine appears to be well tolerated, with no apparent effects on accommodative capacity or glaucoma.

Accommodation, Ocular↗