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J Roider

Publications and source records attributed to J Roider.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Enucleation as a form of self-aggression--2 case reports and review of the literature].

BACKGROUND: Autoenucleation is the worst form of self-mutilation of the eye. Patients affected are mostly those with psychosis and delusions, but such acts can also happen under the influence of drugs, alcohol, solvents and seldom with organic illnesses. Often, these patients are known to be autoaggressive and suicidal. PATIENTS: We present two psychiatric patients who autoenucleated one eye and injured the other. A 41-year-old patient with known organic epilepsy based on a temporal-lobe-hemangioma and psychosis with delusions autoenucleated his right eye and lacerated the conjunctiva of the other, following imperative voices. A 50-year-old female suffered from a long-standing paranoid schizophrenia and religious delusions, and autoaggressive acts with resulting amaurosis of the right eye and several suicidal attempts had preceded the autoenucleation of the left eye. DISCUSSION: After the completion of the autoaggressive act the patients experience relief, but often the autoaggresive or suicidal impulses persist or recur. A close cooperation between ophthalmologists and psychiatrist in these patients is imperative.

Adult↗
PubMed2000

Origin of retinal pigment epithelium cell damage by pulsed laser irradiance in the nanosecond to microsecond time regimen.

BACKGROUND AND OBJECTIVE: Selective photodamage of the retinal pigment epithelium (RPE) is a new technique to treat a variety of retinal diseases without causing adverse effects to surrounding tissues such as the neural retina including the photoreceptors and the choroid. In this study, the mechanism of cell damage after laser irradiation was investigated. STUDY DESIGN/MATERIALS AND METHODS: Single porcine RPE-melanosomes and RPE cells were irradiated with a Nd:YLF laser (wavelength lambda = 527 nm, adjustable pulse duration tau = 250 nsec-3 microsec) and a Nd:YAG laser (lambda = 532 nm, tau = 8 nsec). Fast flash photography was applied to observe vaporization at melanosomes in suspension. A fluorescence viability assay was used to probe the cells vitality. RESULTS: The threshold radiant exposures for vaporization around individual melanosomes and for ED50 cell damage are similar at 8-nsec pulse duration. Both thresholds increase with pulse duration; however, the ED50 cell damage radiant exposure is 40% lower at 3 microsec. Temperature calculations to model the onset of vaporization around the melanosomes are in good agreement with the experimental results when assuming a surface temperature of 150 degrees C to initiate vaporization and a homogeneous melanosome absorption coefficient of 8,000 cm(-1). Increasing the number of pulses delivered to RPE cells at a repetition rate of 500 Hz, the ED50 value decreases for all pulse durations. However, the behavior does not obey scaling laws such as the N 1/4 equation. CONCLUSION: The origin of RPE cell damage for single pulse irradiation up to pulse durations of 3 microsec can be described by a damage mechanism in which microbubbles around the melanosomes cause a rupture of the cell structure. The threshold radiant exposure for RPE damage decreases with increasing number of pulses applied.

Animals↗
PubMed2000

[Correlation of morphologic changes between optical coherence tomography and topographic angiography in a case of gyrate atrophy].

PURPOSE: To characterize ultrastrructual changes in atrophic disease of the retina, RPE and choroid as seen with gyrate atrophy using two new diagnostic modalities, optical coherence tomography (OCT) and topographic angiography. PATIENT AND METHOD: OCT images were taken in a patient with pericentral choroidal atrophy using a slit-lamp-adapted OCT system. Ophthalmoscopy, conventional and topographic angiographic findings were correlated to the reflectivity changes as seen on OCT. RESULTS: Areas of chorioretinal atrophy correlated with a loss of reflectivity in the RPE-choriocapillaris complex on OCT. Additionally OCT identified a thinning of the nerve fiber layer. Topographic angiography demonstrated an extensive defect, seen as an area of depression, consistent with a loss of choriocapillaris and larger-sized choroidal vessels. In contrast to conventional angiography, central islands were not found to demonstrate structural intensity, while the midperipheral surrounding area was clearly elevated to physiological levels. CONCLUSION: OCT and topographic angiography provide in vivo insight into morphologic changes within neurosensory retina and choroid caused by pericentral choroidal atrophy.

Choroid↗
PubMed2000

[Dislocation of artificial lenses into the vitreous body. Long-term follow-up of 6 patients].

BACKGROUND: Dislocation of an artificial intraocular lens (IOL) into the vitreous is a rare complication in cataract surgery. The removal of the IOL from the vitreous can be associated with various difficulties. As vitreal surgery in Latvia has been developed only during the last two years, patients with IOL dislocation prior to that time were only observed. The aim this study was the long-term observation of this patients. PATIENTS AND METHODS: 6 patients with dislocated IOLs in the vitreous were observed over various periods of time: 1 patient for 6 years, 2 patients for 3 years, 2 patients for 2 years and in 1 patient for 1 year. A second IOL was implanted into the anterior chamber in two cases. RESULTS: In all cases the retina remained attached. Intraocular pressure was below 20 mmHg. Visual acuity was 0.4 (20/28) and 0.5 (20/40) in the two cases with secondary anterior chamber IOL. In the other cases visual rehabilitation was achieved with spectacles or contact lenses. Visual acuity was 0.7 (20/28) in one patient, 0.4 (20/50) in two patients and 0.1 (20/200) in one patient. CONCLUSION: Dislocated artificial intraocular lenses can remain in the vitreous for a long time without serious complications, if no vitreal surgery is possible.

Adult↗
PubMed2000

[Complications after external retinal surgery in pseudophakic retinal detachment--are scleral buckling operations still current?].

BACKGROUND: After conventional buckling procedures for pseudophakic retinal detachment the primary reattachment rate is 60 to 90% according to literature. Primary vitrectomy may be advantageous in these cases. The purpose of this study was to investigate the spectrum and role of potential side effects like anisometropia and diplopia, to find arguments for or against primary vitrectomy. Also risk factors for pseudophakic retinal detachment were analyzed in our study group, because they may be different from former studies, which were mostly undertake at the time of ec cataract extraction. PATIENTS AND METHODS: The data from 115 patients (120 eyes) with pseudophakic retinal detachment, who undergone buckling procedure between 1991 and 1996 were retrospectively reviewed. We analyzed the retinal reattachment rate, choroidal detachment, postoperative visual acuity, refraction, occurrence of diplopia, anisometropia and metamorphopsia. RESULTS: The primary retinal reattachment rate was 83.3%. There was a retinal redetachment rate of 16.7%. The primary PVR-rate was 4.2%. After the first reoperation an reattachment rate of 91.6% could be achieved, after the second one an overall rate of 95%. A choroidal detachment occurred in 29.2%. Postoperatively (26.5 months +/- 17.2) we found a cellophane maculopathy in 26.5% with consecutive metamorphopsia in 12.1%. 13 patients (15.9%) complained about diplopia, which had to be corrected by operation in 2 cases and prismatic glasses in 4 cases. Anisometropia could be deserved in 16.4%. The buckling procedures caused refractive changes of -1.80 dpt +/- 1.78 after an encircling band and +0.38 dpt +/- 1.01 after a plombage (average -1.05 +/- 1.86). 20% of patients treated with an encircling band developed anisometropia and only 8.3% of patients with a plombage. Postoperatively the visual acuity raised significantly from 0.3 to 0.6 (median). Best visual recovery could be observed in patients, who underwent only one operation. CONCLUSIONS: The primary retinal reattachment rate in pseudophakic retinal redetachment after conventional buckling procedures in our patients are comparable to those in the literature. In spite of phacoemulsification the risk-factors for pseudophakic retinal detachment has not changed. A considerable number of patients complained about postoperative complications like anisometropia and diplopia, which could be avoided by primary vitrectomy. To compare anatomic and functional results of both procedures a randomized prospective study should be undertaken.

Adult↗
PubMed2000

[Clinical results of intravitreal administration of tissue-type plasminogen activator (tPA) and gas for removal of subretinal hemorrhage in senile macular degeneration].

BACKGROUND: Subretinal hemorrhage in age related macular degeneration (AMD) usually causes acute visual loss and is associated with poor visual prognosis. In order to prevent retinal damage and to perform laser treatment of the underlying choroidal neovascularization (CNV) the subretinal hemorrhage has to be removed from the macular region. This could be achieved by intravitreal injection of tissue plasminogen activator (tPA) and gas. PATIENTS AND METHODS: In 8 consecutive patients, suffering from a massive macular hemorrhage (duration of visual problems: mean 9 days), tissue plasminogen activator (tPA) (40 micrograms in 400 microliters BSS) and SF6-gas (0.75 ml) was transsclerally injected into the vitreous cavity to achieve liquification and displacement of the hemorrhage. RESULTS: In all patients liquification and displacement of the hemorrhage out of the macular region was achieved during follow up. During the first week after operation a significant increase of visual acuity was noticed in all patients, however ophthalmoscopically there was just little reduction of the hemorrhage in the foveolar area. After successful removal of the blood the choroidal neovascularization was treated successfully by laser coagulation in one patient. No laser treatment was performed in the other patients because of the subfoveal location of the neovascularisation or because of disciform scar. Visual acuity increased 4 lines after surgery. In one case the procedure was complicated by a persistent vitreous hemorrhage and vitrectomy had to be performed in another patient due to an endophthalmitis. CONCLUSION: Intravitreal injection of tPA assisted gas displacement of subretinal hemorrhage due to AMD leads to a significant increase of visual acuity during the first week after operation. Although a nearly complete removal of the hemorrhage out of the macular area could be achieved, it was difficult to differentiate this from the spontaneous course. Laser photocoagulation could be performed in only few cases.

Aged↗
PubMed2000

Subthreshold (retinal pigment epithelium) photocoagulation in macular diseases: a pilot study.

BACKGROUND: Subthreshold (retinal pigment epithelium) photocoagulation is a new photocoagulation method, which treats the retinal pigment epithelium (RPE) and avoids damage to the neural retina. The initial results in this prospective pilot study on various macular diseases are presented. METHODS: 12 patients with diabetic maculopathy (group I), 10 with soft drusen (group II), and four with central serous retinopathy (CSR) (group III) were treated and followed up for 1 year. Treatment was achieved using a train of repetitive short laser pulses (1.7 micros) of a green Nd:YLF laser (parameters: 527 nm, 100 and 500 pulses, repetition rate: 500 Hz, spot size: 160 microm, energies: 70-100 microJ). Laser energy was based on the visibility of test lesions on fluorescein angiography (50-130 microJ). Patients were examined at various times by ophthalmoscopy, fluorescein and ICG angiography, and infrared imaging. RESULTS: After 6 months hard exudates disappeared in six out of nine patients in group I and leakage disappeared in six out of 12 diabetic patients. In group II drusen were less in seven out of 10 patients. In group III serous detachment disappeared in three out of four cases. Visual acuity was stable in all cases. None of the laser lesions was clinically visible immediately. After 1 day most lesions were visible as yellowish RPE depigmentation. After 3 months some of the lesions were visible as hyperpigmented areas but most were not. Fluorescein angiography showed leakage only in the first week. Infrared imaging showed that most lesions can be visualised in groups I and II after a period longer than 1 week as hyperreflective areas. CONCLUSION: This study showed that subthreshold (RPE) photocoagulation is effective in some cases of diabetic maculopathy, drusens, and in CSR. Visibility of laser burns is not always necessary in the treatment of macular diseases presented here. Infrared imaging is an effective and non-invasive way of visualising subthreshold (RPE) laser burns.

Aged↗
PubMed1999

Retinal sparing by selective retinal pigment epithelial photocoagulation.

OBJECTIVE: To investigate whether photocoagulation of the retinal pigment epithelium is possible with sparing of the photoreceptors. METHODS: Mild laser effects of a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) were applied to 17 patients. To establish the necessary energy, test exposures were performed to the lower macula (laser variables: 1.7 microseconds, 100 and 500 pulses applied in a train at 500 Hz, 20-130 microJ, 160 microm). Of 179 test lesions, 73 were followed up at various time intervals up to 1 year by performing microperimetry directly on top of the laser lesions. RESULTS: All of the test lesions were at the threshold of retinal pigment epithelial disruption, and none of the laser effects were visible by ophthalmoscopy during photocoagulation; they were detectable only by fluorescein angiography. After exposure with 500 pulses, retinal defects were detected in up to 73% of the patients (100 microJ) after the first day. Most of these defects were no longer detectable after 3 months. After exposure with 100 pulses, no defects could be detected with 70 and 100 microJ after 1 day. The absence of microscotomas in the follow-up period suggests that retinal damage was minimal or, if it occurred, was functionally repaired. CONCLUSION: By choosing proper energy and number of pulses, it is possible to produce retinal pigment epithelial effects with no subsequent retinal damage detectable by microperimetry.

Adult↗
PubMed1999

Variability of RPE reaction in two cases after selective RPE laser effects in prophylactic treatment of drusen.

BACKGROUND: The value of prophylactic photocoagulation of soft drusen is unclear. Photocoagulation is usually performed by a continuous wave laser. METHODS: We report the cases of two patients with age-related macular degeneration with soft drusen who were treated by selective retinal pigment epithelium (RPE) photocoagulation of a pulsed Nd:YLF (527 nm) laser. Laser parameters were: wavelength 527 nm, number of pulses in a train 500, pulse duration 1.7 microseconds, energy per pulse 70 microJ, spot size 160 microns, repetition rate 500 Hz. RESULTS: Dosimetry performed individually showed that in both patients laser photocoagulation was performed at the threshold of RPE disruption. None of the laser effects was visible during photocoagulation. They were detectable only by fluorescein angiography. Despite identical photocoagulation parameters the RPE reaction was completely different. In the first patient RPE hyperpigmentation was notable at most photocoagulation sites and the drusen had disappeared after 6 months. In the second patient the laser effects were not visible after 6 months by biomicroscopy and the drusen stayed unchanged. CONCLUSION: These findings could reflect different repair mechanisms of the RPE after alteration and could represent a sign of a different viable stage in the life of RPE cells. Close attention should be paid to this phenomenon in the various drusen studies currently under way.

Fluorescein Angiography↗
PubMed1999

Treatment of traumatic cyclodialysis with vitrectomy, cryotherapy, and gas endotamponade.

An aphakic patient with severe chronic hypotony had an alternative treatment of a traumatic cyclodialysis cleft: a 3-port pars plana vitrectomy, cryotherapy of the cleft, and fluid-gas exchange with subsequent supine positioning. The therapeutic principle was mechanical apposition of the detached ciliary muscle to the scleral spur by the gas bubble and scar induction by cryotherapy. Intraocular pressure increased to within normal ranges, and visual acuity improved over a 15 month follow-up.

Air↗
PubMed1999

[Epidemiology of open globe injuries].

BACKGROUND: Severe open globe injuries are frequent emergencies in an ophthalmologic clinic and required immediate operation. The extent of these injuries is various depending on the mechanism of the injury and involvement of ocular tissue. In many cases a full visual rehabilitation can be achieved but in a lot of cases blindness results. To prevent such severe eye injuries it is important to judge the leading injury mechanisms. For this we collected our data about open globe injuries. PATIENTS AND METHODS: Retrospectively we collected the data from 103 consecutive patients in the year 1996 and 1997, presenting with an open globe eye injury followed by operation. The data contained personal patients data, information about mechanism of injury, visual acuity, operation and rehabilitation. Statistical analysis was performed using binomimal-test and t-test for paired and unpaired samples (p < 0.05). RESULTS: 85.4% were male. Most of the injuries happened at home (38%) and at the working place (31%). Assaultive injuries happened in 6.8%. 35% of all patients were craftmen (mechanics, electricians, or the locksmith were preferred). Pensioners were affected in 14.6% of all cases followed by small children (7.8%) and school children (7.8%). In 50% of all cases metal and glass were responsible for the trauma, explosions were noticed in 8.7%. An intraocular foreign body was found in 37.9%. In 62% of all cases no second operation was necessary. An enucleation during the follow-up was performed in 2 cases. CONCLUSION: At least a third of all severe eye injuries would have been preventable. Concerning the non-preventable injuries accidents at home and in children were predominating. The rate of the open globe injuries was 2.32 in 100.000 people, which is about the same like in US-American studies. Most of the injuries happened at home because of carelessness and would have been avoidable. The rate of injuries at the working place is significantly higher than in the USA but there were significantly more gun-shot-injuries or offensive accidents abroad. The rate of accidents at home and in traffic were the same. We think that public campaigns and prevention strategies can help to reduce the potential risk of severe eye injuries.

Accidents, Home↗
PubMed1999

Macular injury by a military range finder.

OBJECTIVE: The authors report the clinical findings of a civilian patient who unintentionally looked into the laser beam of a military range finder. Detailed information on the range finder is given. The objective is to illustrate the potential danger of such devices and to give detailed information on the device, the clinical findings associated with exposure, and the laser-tissue interaction mechanism. METHODS: The patient was examined with fluorescein angiography, indocyanine green angiography, microperimetry, and optical coherence tomography, both in the acute stage (2 hours) and 4 weeks later. Fluorescein angiography was performed again 4 months later. A total of 100 mg prednisone tapered over 9 days was prescribed. Additionally, 50 microg tissue plasminogen activator (TPA) and 0.5 mL pure C2F6 were injected in the vitreous. RESULTS: In the acute phase, hemorrhage was located beneath the retina, primarily beneath the retinal pigment epithelium. Retinal defects as seen initially over the subretinal blood were reduced after 4 weeks, but a retinal defect ranging from the lasered site toward the fovea remained. Visual acuity slightly increased from 20/100 to 20/63 after 4 weeks. Indocyanine green angiography showed a large hypofluorescent spot in the macula. Four months after the accident, a classic choroidal neovascularization developed, originating from the lasered site. The technical parameters of the range finder were: Nd:YAG laser (1,064 nm), pulse duration 10 ns, beam divergence 1.5 mrad, energy 10 mJ. CONCLUSION: A range finder can produce severe macular injury. The primary laser-tissue interaction mechanism seems to be explosive disruption of choroidal tissue. Intravitreal injection of TPA and C2F6 did not show a clear benefit to such laser lesions. A late complication can be secondary choroidal neovascularization.

Adult↗
PubMed1999

Laser treatment of retinal diseases by subthreshold laser effects.

The retinal pigment epithelium (RPE) may play an important role in the therapeutic effect of laser photocoagulation. This suggests a benefit from targeting the RPE instead of the sensory retina. Calculating the actual temperature profile after laser photocoagulation, it can be shown that pulse durations have to be in the order of microseconds (micros) to spare the retina from damage. This is consistent with histological findings after laser exposure with repetitive, 5 micros Nd:YLF laser pulses (527 nm). Therapeutic effects have been shown in patients with diabetic macular edema, drusen, and central serous retinopathy.

Animals↗
PubMed1998

Bubble formation as primary interaction mechanism in retinal laser exposure with 200-ns laser pulses.

BACKGROUND AND OBJECTIVE: Retinal laser photocoagulation is generally performed by laser pulses of a few hundred milliseconds. The tissue interaction mechanism is a pure thermal interaction mechanism. As pulse duration gets shorter, different, non-thermal interaction mechanisms start to appear. The time domain for a change of tissue interaction mechanism seems to be in the ns and micros range. The goal of this study was to characterize the tissue interaction mechanism with 200-ns laser pulses, which approximate the thermal relaxation time of single melanin granules. MATERIALS AND METHODS: The retinas of 19 eyes of 10 rabbits were irradiated by 10 and 500 repetitive laser pulses (wavelength, 532 nm; repetition rate, 500 Hz; pulse duration, 200 ns; per pulse energy, 0-120 microJ; retinal spot size, 100 microm). The effects were evaluated by fluorescein angiography, ophthalmoscopy and by theoretical thermal calculations. Light microscopy and transmission electron microscopy were additionally performed on lesions irradiated by 500 pulses. RESULTS: Single pulse threshold energies for angiographic visibility were 3.5 microJ (10 pulses) and 2.1 microJ (500 pulses), for ophthalmoscopic visibility 9.0 microJ (10 pulses) vs. 8.6 microJ (500 pulses). At energy levels above ophthalmoscopic visibility macroscopically visible bubble formation inside the retina could be observed. This occurred at energy levels of 35 microJ (10 pulses) vs. 17 microJ (500 pulses). Microscopic evaluation of lesions irradiated with 500 pulses and energies at the angiographic threshold showed a damage primarily to the RPE. Additional outer segment damage of the photoreceptors could be found. A gap between damaged RPE cells and the outer segments could be repeatedly found as well as damaged RPE cells, which were detached from intact Bruch's membrane. Temperature calculation shows that temperatures above 100 degrees C may exist around single melanin granules. CONCLUSION: The studies suggest that RPE damage may occur by bubble formation around single melanin granules.

Animals↗
PubMed1998

Therapeutic range of repetitive nanosecond laser exposures in selective RPE photocoagulation.

BACKGROUND: The aim of this study was to investigate whether selective damage the RPE while sparing the adjacent photoreceptors is possible with repetitive 200-ns pulses of Nd:YAG laser (532 nm) and what potential side effects can be expected with higher pulse energies. METHODS: We irradiated the retinas of 19 eyes of 10 chinchilla rabbits with 500 pulses from a Nd:YAG laser, each 200 ns in duration, at a repetition rate of 500 Hz (158 microns, 0-120 microJ). Threshold curves for different effects were established. Representative lesions were investigated by light and transmission electron microscopy. RESULTS: It was possible to produce lesions, which were only visible by fluorescein angiography. The ED50 threshold energy per pulse for visibility by fluorescein angiography was 2.1 microJ per pulse, for visibility by ophthalmoscopy 8.6 microJ. Bubble formation, an uncommon phenomenon in retinal photocoagulation, occurred at energies of 15-25 microJ. Hemorrhage occurred at surprisingly high energy levels of more than 100 microJ. Histology performed on lesions visible only by angiography showed damage primarily to the RPE and outer segments, with very little damage to some inner segments dependent on the energy used. CONCLUSIONS: Selective RPE damage is possible with repetitive 200-ns laser pulses and appropriate energy; however, the collateral damage to the adjacent retina is more pronounced than with repetitive microsecond laser pulses. There is no risk of hemorrhage of retinal photocoagulation with the repetitive 200-ns laser pulses at low energy levels which would be used clinically.

Animals↗
PubMed1998

Corneal shape changes after pars plana vitrectomy.

BACKGROUND: The purpose of this prospective, controlled, clinical study was to investigate corneal shape changes due to pars plana vitrectomy (PPV) in patients with potential visual improvement postoperatively. METHODS: A total of 36 consecutive patients undergoing conventional PPV combined with or without macular surgery were studied. Sequential determinations of the corneal curvature by manual keratometry and corneal topography were performed preoperatively, during the first postoperative week, at 4 weeks and after 2-8 months (mean 4 months). RESULTS: The mean surgically induced keratometric astigmatism was 2.92 +/- 1.98 diopters (D) (P < 0.0001) during the first postoperative week. After 4 weeks and 4 months the values decreased to 1.01 +/- 0.97 D and 0.67 +/- 0.43 D, respectively. Videokeratographic analysis confirmed significant curvature changes, with corneal steepening (P < 0.008) which corresponded to the superonasal and temporal semimeridian, and flattening (P < 0.008) along the inferior and inferonasal semimeridians. Corneal changes persisted in some cases for several weeks, partly in an asymmetric and irregular configuration. Shifts in axis to against-the-rule and oblique meridians were noted postoperatively with redistribution within preoperative values in 53% of the cases at 4 weeks after surgery. Subgroup analysis revealed that suture diameter, as well as the use of gas endotamponade, influenced the induced astigmatism. CONCLUSION: A substantial increase of the corneal astigmatism and distinct shape changes can occur after PPV in the immediate postoperative period. Consecutive stabilization at preoperative values was observed after several weeks. The time course of the corneal curvature alterations should be considered in the postoperative management to detect refractive causes of inadequate visual acuity.

Adult↗