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1.
Med Image Anal ; 11(6): 526-39, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17584520

RESUMEN

This paper presents a robust algorithm for calibration and system registration of endoscopic imaging devices. The system registration allows us to map accurately each point in the world coordinate system into the endoscope image and vice versa to obtain the world line of sight for each image pixel. The key point of our system is a robust linear algorithm based on singular value decomposition (SVD) for estimating simultaneously two unknown coordinate transformations. We show that our algorithm is superior in terms of robustness and computing efficiency to iterative procedures based on Levenberg-Marquardt optimization or on quaternion approaches. The algorithm does not require the calibration pattern to be tracked. Experimental results and simulations verify the robustness and usefulness of our approach. They give an accuracy of less than 0.7 mm and a success rate >99%. We apply the calibrated endoscope to the neurosurgical relevant case of red out, where in spite of the complete loss of vision the surgeon gets visual aids in the endoscope image at the actual position, allowing him/her to manoeuvre a coagulation fibre into the right position. Finally, we outline how our registration algorithm can be used also for standard registration applications (establish the mapping between two sets of points). We propose our algorithm as a linear, non-iterative algorithm also for projective transformations and for 2D-3D-mappings. Thus, it can be seen as a generalization of the well-known Umeyama registration algorithm.


Asunto(s)
Algoritmos , Endoscopios , Procesamiento de Imagen Asistido por Computador/métodos , Animales , Calibración , Diseño de Equipo , Imagenología Tridimensional , Ratas , Estadística como Asunto
2.
Br J Ophthalmol ; 80(1): 58-62, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8664235

RESUMEN

AIMS: The efficacy of endoscopic endonasal orbital decompression in dysthyroid orbitopathy was analysed. METHODS: In 21 consecutive cases of bilateral operation short term (10 (SD 6) days after operation) and long term (156 (12) days after operation) results were recorded. RESULTS: Short term results showed that vision of the more affected eye improved from a mean of 0.35 to 0.59; vision improved in all but one eye which remained unchanged. In the fellow eyes mean visual acuity improved from 0.6 to 0.7; three of these eyes showed a decrease. Mean proptosis returned from 23.0 mm to 20.0 mm. As to motility the mean abductive capacity decreased from 5.5 mm to 4.0 mm of monocular excursion, whereas adduction increased from 7.5 mm to 8.5 mm. Upgaze and downgaze did not show any major change. The mean angle of horizontal squint shifted from 7.5 degrees of convergence to 15.5 degrees while no significant vertical or cyclorotational deviation was induced. These immediate postoperative results proved to be stable for the period of long term follow up with only slight changes. No significant bleeding or specific otorhinolaryngological complication without resolve occurred intraoperatively or perioperatively. CONCLUSION: This method is believed to be superior to non-endoscopic techniques because it avoids external scars and antral pain. With regard to the relief of intraorbital pressure, the technique gives good results for visual acuity improvement, but in proptosis reduction the method is not as efficient as external or combined procedures. There seems to be no difference when compared with other approaches in induction of horizontal squint. The method has a protective long term effect against the recurrence of compressive optic neuropathy.


Asunto(s)
Enfermedades Orbitales/cirugía , Enfermedades de la Tiroides/complicaciones , Adulto , Anciano , Endoscopía , Exoftalmia/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Orbitales/etiología , Enfermedades Orbitales/fisiopatología , Resultado del Tratamiento , Agudeza Visual
3.
Br J Ophthalmol ; 87(5): 599-603, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12714403

RESUMEN

AIM: To prospectively assess the efficacy and complications of viscocanalostomy with a reticulated hyaluronic acid implant (VSRHAI) versus standard viscocanalostomy in patients with medically uncontrolled open angle glaucoma. METHODS: A consecutive series of 40 patients (40 eyes) with uncontrolled open angle glaucoma underwent non-penetrating antiglaucomatous surgery. After the excision of the deep scleral flap they were randomly assigned to either a standard viscocanalostomy or additional implantation of a reticulated hyaluronic acid implant. Follow up visits were over a period of 12 months after surgery. RESULTS: The mean preoperative intraocular pressure (IOP) was 26.5 (SD 6.1) mm Hg for all patients enrolled. The mean IOP was 8.1 (SD 5.6) mm Hg 1 day after surgery for the viscocanalostomy group (p<0.001) and 12.0 (SD 5.2) mm Hg for the VSRHAI group (p<0.001). The postoperative IOP difference between the two groups was statistically significant (p = 0.03). The success rate, defined as an IOP lower than 22 mm Hg without medication, was 40% in both groups at 12 months postoperatively (p = 0.90). The number of postoperative complications was equally low for both groups. CONCLUSIONS: Both surgical procedures, viscocanalostomy and VSRHAI, provide comparable success rates over a 1 year follow up period. The specific intraoperative and postoperative complications of non-penetrating surgery were seen in our series, although the overall rate of postoperative complications proved equally low for both techniques.


Asunto(s)
Implantes de Drenaje de Glaucoma , Glaucoma de Ángulo Abierto/cirugía , Ácido Hialurónico/administración & dosificación , Anciano , Femenino , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Cuidados Posoperatorios/métodos , Complicaciones Posoperatorias/etiología , Estudios Prospectivos , Factores de Riesgo , Esclerostomía/métodos , Resultado del Tratamiento
4.
Br J Ophthalmol ; 86(9): 997-1001, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12185126

RESUMEN

AIMS: To examine whether the early postoperative morphology at the site of sclerectomy, as visualised by ultrasound biomicroscopy (UBM), is an indicator of the mechanisms that lower intraocular pressure (IOP) and/or predictors of the long term outcome of viscocanalostomy. METHODS: 15 eyes of 14 patients with medically uncontrolled open angle glaucoma and no history of surgery underwent viscocanalostomy according to Stegmann's technique. Ultrasound biomicroscopy was performed during the first month after surgery. The following parameters were assessed: dimensions of the intrascleral "lake," presence of a filtering bleb, presence of a subconjunctival cavity or a suprachoroidal hypoechoic area, and the thickness of the residual trabeculocorneal membrane. A complete ophthalmological examination was performed the day before and the day after surgery. Follow up visits were scheduled 1 week, 4 weeks, 6 months, and 12 months after surgery. RESULTS: At 1 year successful control of IOP (<20 mm Hg) was achieved without further manipulation or medication in six of 15 eyes. The size of the intrascleral "lake" (average 0.62 mm(3)) did not correlate with later IOP; however, a visible route under the scleral flap and accidental perforation of the trabeculocorneal membrane were associated with long term lowering of IOP. Normal thickness of the trabeculocorneal membrane (0.10-0.15 mm) was indicative of IOP control with and without medication. When UBM showed an early collapse of the intrascleral cavity, control of IOP was not achieved. Other UBM findings did not predict long term function. CONCLUSION: In accordance with previous studies, the authors found that UBM examination is a useful method to evaluate outflow mechanisms after glaucoma surgery. This study shows that UBM imaging of external filtration during the early postoperative period can be used to predict the success of viscocanalostomy. However, to establish conclusively what parameters of UBM predict successful viscocanalostomy a larger number of patients must be studied.


Asunto(s)
Glaucoma de Ángulo Abierto/cirugía , Adulto , Femenino , Glaucoma de Ángulo Abierto/diagnóstico por imagen , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Estudios Retrospectivos , Esclerótica/diagnóstico por imagen , Factores de Tiempo , Malla Trabecular , Resultado del Tratamiento , Ultrasonografía
5.
J Neurosurg ; 93(2): 342-50, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10930024

RESUMEN

In this neuroendoscopic study the authors tested the newly developed "red-out module" of their visual navigation system that enables the neurosurgeon to achieve hemostasis if total visualization is lost due to hemorrhage ("red out") within the visual field. An optical position measurement system connected to the endoscope guarantees that digitized endoscopic images are coupled with the accurate endoscopic position. Computerized images are simultaneously stored with their respective position data, and this creates a virtual anatomical landscape. The system was tested in in vivo bleeding conditions in a rat model. Artificial endoscopic cavities were created in the inguinal, pelvic, and jugular regions in rats to imitate the conditions of the human ventricular system. Two experimental settings were tested: Technique I, in which a computer landmark has been previously determined at the point where the vessel will be lesioned; and Technique II, in which a landmark has been previously set in the surrounding area of the vessel. Immediately after hemorrhage obscures the visual field (red out), the computer automatically displays the virtual images on a separate monitor. The previously set landmarks and the graphic overlay of the coagulation fiber enable the surgeon to navigate within the operative field based on the virtual images and to perform coagulation at the site of the lesion. A total of 175 vessels were coagulated: 43 arteries and 132 veins. In using Technique I, 130 (90.9%) of 143 vessels and in using Technique II, 26 (81.2%) of 32 arteries were successfully coagulated. The authors' data revealed that virtual image guidance has the potential to be a helpful tool in neuroendoscopy.


Asunto(s)
Endoscopía/métodos , Procesamiento de Imagen Asistido por Computador , Hemorragias Intracraneales/diagnóstico por imagen , Procedimientos Neuroquirúrgicos/métodos , Interfaz Usuario-Computador , Animales , Modelos Animales de Enfermedad , Femenino , Hemostasis , Masculino , Radiografía , Ratas , Ratas Wistar
6.
J Cataract Refract Surg ; 21(5): 556-61, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7473120

RESUMEN

Multifocal intraocular lenses (MIOLs) have been designed to provide better uncorrected near visual acuity than monofocal IOLs. However, the increase in depth of focus is combined with a significant decrease in contrast sensitivity and glare. We implanted a new zonal-progressive MIOL (AMO Array) in 31 eyes of 25 patients whose mean age was 60.8 +/- 13.5 years. At 12.1 +/- 2.4 months postoperatively, the uncorrected visual acuity averaged 0.56 +/- 0.09 (20/32) for distance and 0.54 +/- 0.12 (20/40) for near focus. Seventy-five percent of patients achieved a best corrected distance visual acuity of > or = 0.9 (20/22). With distance correction only, mean near visual acuity was 0.72 +/- 0.17 (20/25). Best corrected near acuity reached 0.89 +/- 0.11 (20/22), requiring an additional near add of +1.0 to +2.0 diopters (D). We observed an age-dependent difference in the depth of focus. In younger patients (46 +/- 6 years), the pseudoaccommodation range was 6.25 D; acuity attained was > or = 0.4 (20/50). In older patients (71 +/- 7 years), visual acuity at the near focus was substantially reduced (two lines). Regan contrast sensitivity was lower for MIOL patients at all contrast levels, but the difference was statistically significant only at very low contrast (11%). Contrast sensitivity and glare were dependent on the patient's age but did not change with the amount of postoperative astigmatism. Younger patients were very satisfied with the results of MIOL implantation, and the small loss of contrast sensitivity was counterbalanced by the advantage of improved depth of focus and uncorrected near visual acuity.


Asunto(s)
Astigmatismo/etiología , Lentes Intraoculares , Acomodación Ocular , Factores de Edad , Anciano , Sensibilidad de Contraste , Humanos , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Prospectivos , Diseño de Prótesis , Agudeza Visual
7.
J Cataract Refract Surg ; 22 Suppl 1: 788-93, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-9279673

RESUMEN

PURPOSE: To compare the anti-inflammatory effect of diclofenac sodium 0.1% ophthalmic solution, flurbiprofen 0.03% ophthalmic solution, and indomethacin 1.0%. SETTING: Department of Ophthalmology, University of Köln, and Bundesknappschaftskrankenhaus, Sulzbach, Germany. METHODS: One hundred seventeen patients enrolled in this prospective, randomized, double-masked, and parallel-group study had phacoemulsification and intraocular lens implantation and received one of the three solutions. Preoperatively at day 1 and postoperatively at day 4 or 5 and day 12, 13, or 14, they were examined by slitlamp, applanation tonometry, and laser flare meter. RESULTS: Anterior chamber flare reduction from baseline was significantly greater in the diclofenac group than in the flurbiprofen group (P = .022). Patients in the diclofenac group had significantly less burning and stinging than those in the flurbiprofen and indomethacin groups at postoperative days 4-5 and 12-14 (P = .001). CONCLUSION: Diclofenac sodium appeared to be more potent than flurbiprofen in controlling intraocular inflammation after cataract surgery and appeared to be locally tolerated better than flurbiprofen and indomethacin.


Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Diclofenaco/administración & dosificación , Endoftalmitis/prevención & control , Flurbiprofeno/administración & dosificación , Indometacina/administración & dosificación , Complicaciones Posoperatorias/prevención & control , Administración Tópica , Adulto , Antiinflamatorios no Esteroideos/efectos adversos , Diclofenaco/efectos adversos , Método Doble Ciego , Endoftalmitis/etiología , Endoftalmitis/patología , Femenino , Flurbiprofeno/efectos adversos , Estudios de Seguimiento , Humanos , Indometacina/efectos adversos , Lentes Intraoculares/efectos adversos , Masculino , Soluciones Oftálmicas , Facoemulsificación/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patología , Estudios Prospectivos , Resultado del Tratamiento
8.
J Cataract Refract Surg ; 22(10): 1465-70, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9051504

RESUMEN

PURPOSE: To study of the effect of silicone intraocular lens (IOL) implantation using a 3.0 mm tunnel incision with that of implantation though a 6.0 mm corneoscleral incision after phacoemulsification in human eyes. SETTING: Department of Ophthalmology, University of Köln, Germany. METHODS: In a prospective, randomized clinical study, 50 patients with senile cataract had phacoemulsification and IOL implantation through a 3.0 mm tunnel or a 6.0 mm corneoscleral incision. To assess blood-aqueous barrier (BAB) disruption, preoperative and postoperative sodium fluorescein concentrations in the anterior chamber were measured with the Fluorotron Master II. Diclofenac sodium 0.1% was applied to the operative eyes five times a day for 5 days. The contralateral eyes served as controls. RESULTS: There was no significant between-group difference in sodium fluorescein concentrations in the 5 days after surgery. CONCLUSION: The findings underline our clinical impression that BAB disruption 5 days after surgery does not differ significantly with the type and length of scleral incision used for IOL implantation.


Asunto(s)
Barrera Hematoacuosa/fisiología , Córnea/cirugía , Lentes Intraoculares , Facoemulsificación/métodos , Esclerótica/cirugía , Técnicas de Sutura , Análisis de Varianza , Cámara Anterior/irrigación sanguínea , Humor Acuoso/metabolismo , Córnea/fisiología , Fluorofotometría , Estudios de Seguimiento , Humanos , Complicaciones Posoperatorias , Estudios Prospectivos , Esclerótica/fisiología
9.
J Cataract Refract Surg ; 26(6): 937-40, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10889444

RESUMEN

A 4-year-old boy with Marfan's syndrome had severe visual impairment after subluxation of the crystalline lens with bisection of the pupil. In the first eye, a capsular tension ring and an intraocular lens (IOL) were uneventfully placed in the capsular bag after phacoemulsification. During implantation of the endocapsular tension ring in the second eye, an inadvertent tear of the anterior capsule occurred, and the posterior chamber IOL was placed in the sulcus. In both eyes, severe lens epithelial proliferation with secondary IOL decentration developed postoperatively. Several surgical revisions were necessary to keep the IOL within the optical axis. In the eye with the sulcus-implanted IOL, the endocapsular tension ring was markedly decentered.


Asunto(s)
Cápsula del Cristalino/cirugía , Implantación de Lentes Intraoculares/efectos adversos , Subluxación del Cristalino/cirugía , Lentes Intraoculares , Síndrome de Marfan/complicaciones , Capsulorrexis , Preescolar , Migración de Cuerpo Extraño/etiología , Migración de Cuerpo Extraño/patología , Migración de Cuerpo Extraño/cirugía , Humanos , Cápsula del Cristalino/patología , Subluxación del Cristalino/etiología , Subluxación del Cristalino/patología , Masculino , Falla de Prótesis , Reoperación , Agudeza Visual
10.
J Cataract Refract Surg ; 27(2): 333-6, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11226804

RESUMEN

Two patients, both with bilateral uveitis, had synechiolysis, continuous curvilinear capsulorhexis (CCC), phacoemulsification, and in-the-bag implantation of a foldable single-piece plate-haptic silicone intraocular lens (IOL) in 1 eye. Several weeks postoperatively, massive anterior capsule shrinkage with obstruction of the visual axis occurred in both patients. Surgical revision was performed in both eyes. Both patients had CCC and phacoemulsification and confirmed in-the-bag acrylic IOL implantation in the second eye months after surgery in the first eye. Follow-up examinations showed no significant shrinkage of the anterior capsule opening in any eye. In patients with uveitis, intraoperative lens epithelial cell removal, creation of a large CCC, and careful selection of IOL style and material may prevent occlusion of the anterior capsule opening.


Asunto(s)
Cápsula del Cristalino/patología , Enfermedades del Cristalino/etiología , Implantación de Lentes Intraoculares/efectos adversos , Lentes Intraoculares , Elastómeros de Silicona , Uveítis/complicaciones , Anciano , Capsulorrexis , Humanos , Enfermedades del Cristalino/diagnóstico , Masculino , Persona de Mediana Edad , Facoemulsificación , Reoperación
11.
Cornea ; 19(4): 556-7, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10928777

RESUMEN

PURPOSE: Viscocanalostomy in accordance with Stegmann's technique is a new surgical option in the treatment of glaucoma. There are few reports available describing the specific complications of viscocanalostomy. We report a case of intracorneal inclusion of high-molecular-weight sodium hyaluronate following viscocanalostomy. CASE REPORT: A 66-year-old man with uncontrolled primary open angle glaucoma of his right eye and a history of argon laser trabeculoplasty underwent viscocanalostomy in accordance with Stegmann's technique. During the filling of Schlemm's canal, a limited lysis of Descemet's membrane advanced centrally in the clear cornea adjacent to the site of canalostomy forming an intracorneal bubble of high-molecular-weight sodium hyaluronate. Postsurgical slit-lamp biomicroscopy showed an intracorneal clear bubble within the corneal periphery without evidence of adjacent corneal edema and with no contact between the corneal endothelium and the iris. Follow-up examinations determined that the appearance of the corneal inclusion, essentially, was unchanged, with only a slight tendency of resorption. No signs of corneal scarring or endothelial decompensation could be noted. CONCLUSION: To date, we could not determine a significant corneal damage in conjunction with the described complication. However, it is difficult to predict the long-term clinical course of our patient. Corneal decompensation as a result of possible endothelial toxicity of high-molecular weight sodium hyaluronate as well as spontaneous absorption seem possible.


Asunto(s)
Edema Corneal/inducido químicamente , Lámina Limitante Posterior/patología , Cirugía Filtrante/efectos adversos , Glaucoma de Ángulo Abierto/cirugía , Ácido Hialurónico/efectos adversos , Anciano , Edema Corneal/patología , Lámina Limitante Posterior/diagnóstico por imagen , Lámina Limitante Posterior/cirugía , Glaucoma de Ángulo Abierto/patología , Humanos , Ácido Hialurónico/administración & dosificación , Inyecciones , Presión Intraocular , Masculino , Colgajos Quirúrgicos , Ultrasonografía , Agudeza Visual
12.
Ophthalmologe ; 94(1): 33-7, 1997 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-9132126

RESUMEN

In a prospective, randomised, double-masked, parallel-group study we compared the antiinflammatory effect of diclofenac sodium 0.1%, flurbiprofen 0.03%, and indomethacin 1.0% ophthalmic suspension in 99 patients undergoing phacoemulsification and posterior chamber lens implantation. The reduction in anterior chamber flare from day 1, as measured with the laser flare-meter (FM-500, KOWA) on day 4-5 postoperatively was significantly greater in the diclofenac group than with flurbiprofen (p = 0.022). Patients treated with diclofenac had significantly less burning and stinging than patients on flurbiprofen and indomethacin on postoperative days 4-5 (p < 0.0001) and 12-14 (p = 0.001). Diclofenac sodium appears to be more potent than flurbiprofen in controlling intraocular inflammation after cataract surgery, while having better local tolerance than flurbiprofen or indomethacin.


Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Endoftalmitis/prevención & control , Lentes Intraoculares , Facoemulsificación , Complicaciones Posoperatorias/prevención & control , Adulto , Anciano , Diclofenaco/administración & dosificación , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Flurbiprofeno/administración & dosificación , Humanos , Indometacina/administración & dosificación , Masculino , Persona de Mediana Edad , Soluciones Oftálmicas , Estudios Prospectivos
13.
Ophthalmologe ; 96(6): 410-2, 1999 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-10429502

RESUMEN

BACKGROUND: Incarceration of the iris is a potential complication following trabeculectomy in primary congenital glaucoma. Although this complication is mentioned in the literature, nothing is reported about the technique of surgical revision. PATIENT: In a patient with primary congenital glaucoma we had to perform surgical revision of the anterior chamber, because progressive pupil peaking had developed after trabeculectomy and the optical axis had been obstructed. Simple resolving of uveal tissue from the incarceration site was not possible; the iris incarceration had to be cut under gonioscopic control. CONCLUSION: Surgical revision of an incarceration of the iris can be safely performed by means of gonioscopy. The outcome of intraocular pressure is not necessarily influenced.


Asunto(s)
Glaucoma/congénito , Enfermedades del Iris/cirugía , Complicaciones Posoperatorias/cirugía , Trabeculectomía , Femenino , Glaucoma/cirugía , Humanos , Lactante , Iris/cirugía , Microcirugia/instrumentación , Reoperación , Instrumentos Quirúrgicos
14.
Ophthalmologe ; 89(4): 342-5, 1992 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-1304212

RESUMEN

In a randomized, double-blind clinical trial we studied the protective effect of prednisolone-acetate 1.0% and dexamethasone 0.1% on the blood-aqueous barrier after cataract-extraction and posterior chamber lens implantation. Pre- and postoperative anterior chamber fluorophotometry was performed after i.v. administration of 10% fluorescein-sodium in 20 eyes of 20 patients of whom 16 finished the study (mean age 68.7 +/- 11.0; 13 female, 3 male). The topical application of either drug 5 times daily for 5 days did show a significant difference in surgery mediated disturbance of BAB in each group before and after phacoemulsification. However, when comparing the effect of the two drugs with each other, a difference could not be detected (p = 0.35). To attain a statistical 95% probability that there is no significant difference between the two treatment groups, a number of 690 patients would have had to be investigated. The results can be interpreted as to be due to a better cornea penetration of prednisolone-acetate which compensate the higher glucocorticoid-potency and receptor-affinity of dexamethasone. The untreated fellow-eyes did not reveal a significant difference between the pre- and postoperative anterior chamber fluorescein-concentrations in either treatment group. Anterior chamber fluorophotometry is able to demonstrate the potency and influence of both prednisolone-acetate 1.0% and dexamethasone 0.1% eye-drops on the BAB following phacoemulsification and IOL-implantation. The difference of both drugs does not seem to be of clinical importance in this context.


Asunto(s)
Cámara Anterior/irrigación sanguínea , Humor Acuoso/efectos de los fármacos , Permeabilidad Capilar/efectos de los fármacos , Dexametasona/administración & dosificación , Prednisolona/análogos & derivados , Anciano , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Fluorofotometría , Humanos , Masculino , Persona de Mediana Edad , Prednisolona/administración & dosificación
15.
Ophthalmologe ; 101(12): 1220-3, 2004 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-15064969

RESUMEN

BACKGROUND: Lately, the application of intrascleral implants has been increasingly discussed to improve success rates of nonpenetrating surgery for the treatment of open-angle glaucoma. PATIENTS AND METHODS: A 36-year-old male patient with medically uncontrolled pigmentary glaucoma underwent viscocanalostomy with intrascleral implantation of reticulated hyaluronic acid (SK-GEL) in his right eye. RESULTS: The immediate postoperative course was unremarkable with control of intraocular pressure without additional glaucoma medications. At first follow-up, 2 weeks post surgery, conjunctival dehiscence with partial extrusion and exposure of the reticulated hyaluronic acid implant was observed. Under topical tobramycin ointment a gradual limbal readaptation of the conjunctiva over the surface of the exposed parts of the implant with formation of a filtration bleb was noted. Therefore, surgical revision remained unnecessary. CONCLUSIONS: Implant exposure following nonpenetrating antiglaucomatous surgery is a specific complication, which can appear whenever intrascleral implants are used. Depending on the local situation nonsurgical treatment may be successful.


Asunto(s)
Implantes de Drenaje de Glaucoma , Glaucoma de Ángulo Abierto/cirugía , Ácido Hialurónico/administración & dosificación , Adulto , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Estudios de Seguimiento , Humanos , Ácido Hialurónico/efectos adversos , Presión Intraocular , Masculino , Pomadas , Factores de Tiempo , Tobramicina/administración & dosificación , Tobramicina/uso terapéutico
16.
Ophthalmologe ; 100(3): 230-3, 2003 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-12640553

RESUMEN

BACKGROUND: Lately there has been growing interest in deep sclerectomy as a therapeutic approach for the management of congenital glaucoma.In theory, its pressure-lowering effect is independent of external filtration, which minimizes the risk of failure due to conjunctival or episcleral scarring. In patients who have failed to benefit from previous filtering procedures and have refractory congenital glaucoma,deep sclerectomy could become an alternative. PATIENTS AND METHODS: A 3-year-old girl with refractory congenital glaucoma underwent deep sclerectomy in her left eye. Intraoperatively, percolation through the trabeculodescemetic window was weak, so that the procedure was supplemented by a trabeculotomy. RESULTS: By now, throughout a follow-up period of 20 months, stabilisation of disc cupping and ocular axial length has been achieved without additional glaucoma surgery or medications. CONCLUSIONS: In patients with congenital glaucoma,the combination of deep sclerectomy with trabeculotomy may provide an additional therapeutic approach whenever the prospect of success appears to be limited with deep sclerectomy alone.


Asunto(s)
Glaucoma/congénito , Esclerótica/cirugía , Trabeculectomía , Preescolar , Femenino , Estudios de Seguimiento , Glaucoma/diagnóstico por imagen , Glaucoma/cirugía , Humanos , Disco Óptico/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Esclerótica/diagnóstico por imagen , Ultrasonografía
17.
Comput Aided Surg ; 3(3): 144-8, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9888201

RESUMEN

We developed a navigation support system for endoscopic interventions that allows three-dimensional (3-D) information to be extracted from endoscopic video data and superimposed onto such live video sequences. The endoscope is coupled to a position measurement system and a video camera as components of a calibrated system. In this article we show that the radial distortions of the wide-angle endoscopic lens system can be successfully corrected and an overall accuracy of about 0.7 mm is achievable. Tracking on live endoscopic video sequences allows accurate 3-D depth data to be obtained from multiple camera views.


Asunto(s)
Endoscopios , Procedimientos Neuroquirúrgicos/instrumentación , Terapia Asistida por Computador/instrumentación , Calibración , Endoscopía/métodos , Endoscopía/estadística & datos numéricos , Diseño de Equipo/estadística & datos numéricos , Humanos , Microcomputadores , Procedimientos Neuroquirúrgicos/métodos , Procedimientos Neuroquirúrgicos/estadística & datos numéricos , Televisión/instrumentación , Terapia Asistida por Computador/métodos , Terapia Asistida por Computador/estadística & datos numéricos
18.
Comput Aided Surg ; 3(3): 134-43, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9888200

RESUMEN

We developed a new system to couple the endoscope to an optical position measurement system (OPMS) so that the image frames from the endoscope camera can be labeled with the accurate endoscopic position. This OPMS is part of the EasyGuide Neuro navigation system, which is used for microsurgery and neuroendoscopy. Using standard camera calibration techniques and a newly developed system calibration, any 3-dimensional (3-D) world point can be mapped onto the view from the endoscope. In particular, we can display the coordinates of any anatomical landmark of the patient as it is viewed from the current position of the camera. This and other image-processing techniques are applied to the labeled frame sequence in order to offer the neurosurgeon a variety of control modules that increase the safety and flexibility of neuroendoscopic operations. Several modules, including a new motion alarm system and the "tracking" and "virtual map" modules, were tested in a human cadaveric model using the frontal and occipital approaches. A failure rate of 8.6% was experienced during testing of the first version of the software, but the second version was 100% successful. Thus, an endoscopic navigation system based on digital image processing has been developed that could be a revolutionary advance in image-guided surgery.


Asunto(s)
Endoscopios , Procesamiento de Señales Asistido por Computador/instrumentación , Terapia Asistida por Computador/instrumentación , Cadáver , Calibración , Endoscopía/métodos , Diseño de Equipo , Humanos , Microcirugia/instrumentación , Microcirugia/métodos , Procedimientos Neuroquirúrgicos/instrumentación , Procedimientos Neuroquirúrgicos/métodos , Terapia Asistida por Computador/métodos , Interfaz Usuario-Computador
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