RESUMEN
The Serratia marcescens hemolysin represents a new type of hemolysin and has been studied in great molecular detail with regard to structure, activation and secretion. It has nothing in common with the pore forming toxins of E. coli type (RTX toxins), the Staphylococcus aureus alpha-toxin or the thiol activated toxin of group A beta-hemolytic streptococci (Streptolysin O). Studies on erythrocytes, eukaryotic cells and artificial black lipid membranes, have shown that the mechanism of pore formation of ShlA is different form other pore forming toxins. The S. marcescens hemolysin proteins ShlB and ShlA exhibit protein sequence homologues in Proteus mirabilis, Haemophilus ducreyi, Edwardsiella tarda and Erwinia chrysantemi. Furthermore, sequence motifs present in ShlA and Shlb have been shown to be important for activity and secretion of the S. marcescens hemolysin. Thus, the S. marcescens hemolysin forms the prototype of a new class of hemolysins and of a new secretory mechanism. The uniqueness of this new mechanism is underlined by the fact that activation of ShlA by ShlB strictly requires phosphatidylethanolamine as a cofactor. New data implicate a conformational change in ShlA during activation. In addition, ShlA not only forms pores in erythrocytes but also in fibroblasts and epithelial cells. The cytotoxic action of ShlA is mainly determined by lysis of infected cells in vitro. In sublytic doses, as will normally be the situation in vivo, ShlA exerts additionally effects which are currently under investigation. The knowledge of the structure, activation, secretion and mode of action of S. marcescens hemolysin has implications for proteins, related in sequence or in mode of secretion and activation.
Asunto(s)
Proteínas Bacterianas , Proteínas Hemolisinas/química , Serratia marcescens/química , Animales , Adhesión Bacteriana , Toxinas Bacterianas/química , Toxinas Bacterianas/clasificación , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacología , Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Eritrocitos/efectos de los fármacos , Células Eucariotas/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/fisiología , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacología , Proteínas Hemolisinas/fisiología , Humanos , Lípidos de la Membrana/metabolismo , Operón , Infecciones Oportunistas/sangre , Infecciones Oportunistas/microbiología , Fosfolípidos/metabolismo , Células Procariotas/efectos de los fármacos , Ratas , Infecciones por Serratia/sangre , Infecciones por Serratia/microbiología , Serratia marcescens/genética , Serratia marcescens/patogenicidad , Especificidad de la Especie , VirulenciaRESUMEN
We studied the effects of variable amounts of artificial retinal image stabilization (RIS) upon oscillopsia and visual acuity in eight patients with acquired nystagmus due to neurologic disease. We measured horizontal and vertical eye movements with the magnetic search coil technique and used these electronic signals to control the position of a visual stimulus on a screen in front of the patient. We also used an optical device to stabilize images of the real world upon the retina. During electronic stabilization, RIS was progressively increased until oscillopsia was abolished; this was achieved in all eight patients and corresponded to retinal image drift of 5 degrees/sec or less. In five patients with downbeat nystagmus, further increases in RIS caused the oscillopsia to reappear, but in the opposite direction. Electronic stabilization also improved visual acuity in four of five patients; the limitation of improvement could be related to coexistent visual system defects. Using electronic feedback, we could measure the range of RIS that any individual required to abolish oscillopsia; from this measurement, the components of the optical device that were best suited to provide a stable field of vision could be calculated.
Asunto(s)
Enfermedades del Sistema Nervioso/complicaciones , Nistagmo Patológico/terapia , Retina/fisiopatología , Anteojos , Humanos , Nistagmo Patológico/etiología , Nistagmo Patológico/fisiopatología , Oftalmología/instrumentaciónRESUMEN
Head injury in the youngest age group is distinct from that occurring in older children or adults because of differences in mechanisms, injury thresholds, and the frequency with which the question of child abuse is encountered. To analyze some of these characteristics in very young children, the authors prospectively studied 100 consecutively admitted head-injured patients 24 months of age or younger who were drawn from three institutions. Mechanism of injury, injury type, and associated injuries were recorded. All patients underwent ophthalmologic examination to document the presence of retinal hemorrhages. An algorithm incorporating injury type, best history, and associated findings was used to classify each injury as inflicted or accidental. The results confirmed that most head injuries in children younger than 2 years of age occurred from falls, and while different fall heights were associated with different injury types, most household falls were neurologically benign. Using strict criteria, 24% of injuries were presumed inflicted, and an additional 32% were suspicious for abuse, neglect, or social or family problems. Intradural hemorrhage was much more likely to occur from motor vehicle accidents and inflicted injury than from any other mechanism, with the latter being the most common cause of mortality. Retinal hemorrhages were seen in serious accidental head injury but were most commonly encountered in inflicted injury. The presence of more serious injuries associated with particular mechanisms may be related to a predominance of rotational rather than translational forces acting on the head.
Asunto(s)
Hemorragia Cerebral/etiología , Hemorragia Retiniana/etiología , Fracturas Craneales/etiología , Accidentes por Caídas , Accidentes de Tránsito , Fenómenos Biomecánicos , Conmoción Encefálica/etiología , Hemorragia Cerebral/clasificación , Maltrato a los Niños/diagnóstico , Preescolar , Contusiones/etiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , Fracturas Craneales/clasificación , Tasa de Supervivencia , Heridas no Penetrantes/clasificación , Heridas no Penetrantes/etiologíaRESUMEN
Seven infants with complete bilateral cataracts were operated on and fitted with extended-wear silicone contact lenses. The infants were matched to 16 normal control subjects. A modified preferential looking technique was used to assess visual acuity; the Bayley Scale of infant Development was administered to measure psychological development. Of the seven infants with cataracts, those operated on prior to 8 weeks of age seemed to have normally developing vision. All others showed a substantial visual lag when compared with the control group. Bayley scores for infants operated on early (before 8 weeks) fell within the range of normal variability. The infants operated on later demonstrated a statistically significant lag in development. Also, a pendular nystagmus was noted in those infants with cataracts who were operated on later.
Asunto(s)
Catarata/congénito , Agudeza Visual , Factores de Edad , Extracción de Catarata , Desarrollo Infantil , Femenino , Humanos , Lactante , Masculino , Psicología Infantil , Pruebas de VisiónRESUMEN
OBJECTIVE: Iridocyclitis has been identified as a dosage-dependent side effect in patients with the acquired immunodeficiency syndrome (AIDS) who are treated for Mycobacterium avium complex (MAC) infection with systemic rifabutin. We reviewed cases of acute hypopyon uveitis occurring in patients with AIDS to establish whether there was an association. DESIGN: Retrospective case series. SETTING: Outpatient clinic and inpatient hospital-based ophthalmology referral practice and infectious disease specialty service. PATIENTS: Seven patients with AIDS, aged 10 to 40 years, presenting with acute unilateral hypopyon mimicking infectious endophthalmitis. MAIN OUTCOME MEASURES: Findings from complete ophthalmological evaluation and ancillary laboratory testing. RESULTS: At the time of presentation, all seven patients were receiving treatment for MAC infection with rifabutin (dosage range, 300 to 600 mg/d) and clarithromycin. Results of microbiological investigations in five patients were negative. Iridocyclitis became bilateral in all seven patients, and hypopyon developed in the contralateral eye in five of seven patients. Hypopyon resolved rapidly with intensive topical corticosteroid therapy. Residual inflammation responded to topical corticosteroids with or without reduction of the rifabutin dosage. CONCLUSIONS: Concomitant use of rifabutin, clarithromycin, and fluconazole may precipitate hypopyon uveitis in patients with AIDS being treated for MAC infection.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Infección por Mycobacterium avium-intracellulare/tratamiento farmacológico , Rifabutina/efectos adversos , Uveítis Anterior/inducido químicamente , Administración Tópica , Adulto , Antiinflamatorios/uso terapéutico , Niño , Claritromicina/uso terapéutico , Quimioterapia Combinada , Femenino , Glucocorticoides , Humanos , Iridociclitis/inducido químicamente , Iridociclitis/tratamiento farmacológico , Masculino , Estudios Retrospectivos , Rifabutina/uso terapéutico , Supuración/inducido químicamente , Supuración/tratamiento farmacológico , Uveítis Anterior/tratamiento farmacológicoRESUMEN
OBJECTIVE: To evaluate the reliability of a new visual acuity testing protocol for children using isolated surrounded HOTV optotypes. METHODS: After initial pilot testing and modification, the protocol was evaluated using the Baylor-Video Acuity Tester (BVAT) to present isolated surrounded HOTV optotypes. At 6 sites, the protocol was evaluated for testability in 178 children aged 2 to 7 years and for reliability in a subset of 88 children. Twenty-eight percent of the 178 children were classified as having amblyopia. RESULTS: Using the modified protocol, testability ranged from 24% in 2-year-olds to 96% in 5- to 7-year-olds. Test-retest reliability was high (r = 0.82), with 93% of retest scores within 0.1 logMAR unit of the initial test score. The 95% confidence interval for an acuity score was calculated to be the score +/-0.125 logMAR unit. For a change between 2 acuity scores, the 95% confidence interval was the difference +/-0.18 logMAR unit. CONCLUSIONS: The visual acuity protocol had a high level of testability in 3- to 7-year-olds and excellent test-retest reliability. The protocol has been incorporated into the multicenter Amblyopia Treatment Study and has wide potential application for standardizing visual acuity testing in children.
Asunto(s)
Ambliopía/terapia , Pruebas de Visión/métodos , Agudeza Visual/fisiología , Ambliopía/fisiopatología , Atropina/uso terapéutico , Niño , Preescolar , Humanos , Midriáticos/uso terapéutico , Reproducibilidad de los Resultados , Privación SensorialRESUMEN
Patients with nystagmus present unique challenges to the ophthalmologist. These patients can be difficult to examine and refract. Treatment options to improve vision or reduce disturbing visual symptoms are limited, which is disappointing to the patient and frustrating to the clinician. This paper will provide the clinician with one method of clinically organizing nystagmus, describe the patients who may benefit from optical treatments, and discuss the methodology used in their implementation. Techniques that will be discussed include patient examination and objective and subjective refraction. Optical treatments discussed include spectacles, prisms, contact lenses, and retinal image stabilization.
Asunto(s)
Nistagmo Patológico/diagnóstico , Nistagmo Patológico/terapia , Refracción Ocular , Lentes de Contacto , Anteojos , Fijación Ocular , Humanos , Pronóstico , Agudeza VisualRESUMEN
From wounds of honey bee pupae, caused by the mite Varroa destructor, coccoid bacteria were isolated and identified as Melissococcus pluton. The bacterial isolate was grown anaerobically in sorbitol medium to produce a toxic compound that was purified on XAD columns, gelfiltration and preparative HPLC. The toxic agent was identified by GC-MS and FTICR-MS as tyramine. The toxicity of the isolated tyramine was tested by a novel mobility test using the protozoon Stylonychia lemnae. A concentration of 0.2 mg/ml led to immediate inhibition of mobility. In addition the toxicity was studied on honey bee larvae by feeding tyramine/water mixtures added to the larval jelly. The lethal dosis of tyramine on 4-5 days old bee larvae was determined as 0.3 mg/larvae when added as a volume of 20 microl to the larval food in brood cells. Several other biogenic amines, such as phenylethylamine, histamine, spermine, cadaverine, putrescine and trimethylamine, were tested as their hydrochloric salts for comparison and were found to be inhibitory in the Stylonychia mobility test at similar concentrations. A quantitative hemolysis test with human red blood cells revealed that tyramine and histamine showed the highest membranolytic activity, followed by the phenylethylamine, trimethylamine and spermine, while the linear diamines, cadaverine and putrescine, showed a significantly lower hemolysis when calculated on a molar amine basis. The results indicate that tyramine which is a characteristic amine produced by M. pluton in culture, is the causative agent of the observed toxic symptoms in bee larvae. Thus this disease, known as European foulbrood, is possibly an infection transmitted by the Varroa destructor mite.
Asunto(s)
Abejas/microbiología , Bacterias Grampositivas/metabolismo , Bacterias Grampositivas/patogenicidad , Tiramina/toxicidad , Animales , Abejas/parasitología , Aminas Biogénicas/toxicidad , Movimiento Celular/efectos de los fármacos , Cromatografía , Cromatografía Líquida de Alta Presión , Cilióforos/efectos de los fármacos , Eritrocitos/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Bacterias Grampositivas/crecimiento & desarrollo , Bacterias Grampositivas/aislamiento & purificación , Hemólisis , Humanos , Larva/efectos de los fármacos , Ácaros/microbiología , Ácaros/fisiología , Pupa/microbiología , Pupa/parasitología , Tiramina/biosíntesis , Tiramina/química , Tiramina/aislamiento & purificaciónRESUMEN
PURPOSE: To document the evolution of ocular motor abnormalities in an infant with carbohydrate-deficient glycoprotein syndrome. METHODS: Case report. An infant with carbohydrate-deficient glycoprotein syndrome type 1a underwent magnetic resonance imaging and infrared eye movement recording. RESULTS: A 10-month-old male with carbohydrate-deficient glycoprotein syndrome type Ia had rapid horizontal oscillations of the eyes when startled or awakened from sleep. Clinical examination confirmed this finding and disclosed congenital ocular motor apraxia with a reduced vestibulo-ocular reflex. Infrared eye movement recording showed ocular flutter and square wave jerks superimposed on a horizontal pendular nystagmus. Magnetic resonance imaging showed diffuse cerebellar hypoplasia. CONCLUSION: Carbohydrate-deficient glycoprotein syndrome type Ia can be associated with multiple cerebellar eye signs including ocular flutter, square-wave jerks, and congenital ocular motor apraxia.
Asunto(s)
Apraxias/etiología , Cerebelo/anomalías , Trastornos Congénitos de Glicosilación/complicaciones , Trastornos de la Motilidad Ocular/etiología , Apraxias/diagnóstico , Trastornos Congénitos de Glicosilación/enzimología , Movimientos Oculares , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Nistagmo Patológico/etiología , Trastornos de la Motilidad Ocular/diagnóstico , Fosfotransferasas (Fosfomutasas)/deficiencia , Reflejo VestibuloocularRESUMEN
We studied ten children with central visual impairment with a known neurologic defect and an abnormal visual-evoked response who had results of repeat electrophysiologic testing evaluated at the Children's Hospital of Philadelphia from December 1989 through July 1991. Central visual impairment is defined as poor visual function with a normal anterior visual pathway. Age at first examination ranged from 5 to 48 months with a followup of two to 31 months. Repeat visual-evoked response testing showed improvement in seven patients and no change in three. Grating acuity as measured by the Teller acuity card procedure, performed in nine of ten patients, improved in seven, showed no change in one, and declined in one. We found a potentially favorable prognosis for those infants with central visual impairment, despite an initially abnormal visual-evoked response. We used a clinical approach to this disorder to improve diagnostic categorization and prognostic capabilities in central visual impairment.
Asunto(s)
Potenciales Evocados Visuales , Trastornos de la Visión/fisiopatología , Encefalopatías/fisiopatología , Preescolar , Electrorretinografía , Estudios de Seguimiento , Humanos , Lactante , Luz , Pronóstico , Agudeza VisualRESUMEN
PURPOSE: To report a computerized method for determining visual acuity in children using the Amblyopia Treatment Study visual acuity testing protocol. METHODS: A computerized visual acuity tester was developed that uses a programmed handheld device that uses the Palm operating system (Palm, Inc, Santa Clara, California). The handheld device communicates with a personal computer running a Linux operating system and 17-inch monitor. At a test distance of 3 m, single letters can be displayed from 20/800 to 20/12. A C program on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. RESULTS: Test-retest reliability was high (r =.92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of left eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. CONCLUSIONS: We have developed a computerized method for measurement of visual acuity. Automation of the Amblyopia Treatment Study visual acuity testing protocol is an effective method of testing visual acuity in children 3 to 7 years of age.
Asunto(s)
Pruebas de Visión/métodos , Agudeza Visual , Ambliopía/diagnóstico , Ambliopía/terapia , Niño , Preescolar , Protocolos Clínicos , Computadores , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Pruebas de Visión/instrumentaciónRESUMEN
BACKGROUND: Penetrating keratoplasty in infancy and childhood has traditionally met with limited visual success due to a combination of unique physiology and technical problems in this patient population. With the advances in microsurgical instrumentation, corneal preservation, and visual developmental physiology ophthalmologists are finding increasing indications for penetrating keratoplasty in the childhood population. The long term results of neonatal penetrating keratoplasty in two patients with unilateral congenital corneal opacification are reported. METHODS: Penetrating keratoplasty was performed on one eye in each of two infants within the first 3 weeks of life. Amblyopia treatment and optical therapy have been continued since surgery. RESULTS: After 6 years both grafts have remained clear. One patient developed the infantile esotropia syndrome. Visual development using Snellen optotypes is age normal for both transplanted eyes. CONCLUSIONS: Penetrating keratoplasty when combined with optical correction and amblyopia therapy may restore and preserve vision in selected patients with congenital corneal opacification if performed in the neonatal period.
Asunto(s)
Córnea/cirugía , Opacidad de la Córnea/cirugía , Queratectomía Fotorrefractiva , Córnea/anomalías , Opacidad de la Córnea/congénito , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Láseres de Excímeros , Estudios Retrospectivos , Tetralogía de FallotRESUMEN
The ocular findings and visual prognosis were reviewed in 24 patients with the Treacher-Collins syndrome who were evaluated in the craniofacial clinic in the Division of Pediatric Ophthalmology at Children's Hospital of Philadelphia between 1980 and 1991. All patients had some abnormality. Vision loss was present in 37% of patients. Amblyopia was present in 33%, significant refractive errors were present in 58%, and anisometropia was documented in 17%. Strabismus was present in 37% and significant lid and adnexal abnormalities were seen in 96%. The prognosis for normal vision in at least one eye is good but vision loss secondary to amblyopia is more resistant to treatment owing to other medical problems and social concerns.
Asunto(s)
Disostosis Mandibulofacial/complicaciones , Trastornos de la Visión/etiología , Adolescente , Adulto , Ambliopía/etiología , Niño , Preescolar , Enfermedades de los Párpados/etiología , Femenino , Humanos , Lactante , Masculino , Disostosis Mandibulofacial/fisiopatología , Pronóstico , Errores de Refracción , Agudeza VisualRESUMEN
BACKGROUND/AIMS: The infantile nystagmus syndrome (INS) usually begins in infancy and may or may not be associated with visual sensory system abnormalities. Little is known about its specific waveforms in the first 6 months of life or their relation to the developing visual system. This study identifies the clinical and ocular motility characteristics of the INS and establishes the range of waveforms present in the first 6 months of life. METHODS: 27 infants with involuntary ocular oscillations typical of INS are included in this analysis. They were evaluated both clinically and with motility recordings. Eye movement analysis was performed off line from computer analysis of digitised data. Variables analysed included age, sex, vision, ocular abnormalities, head position, and null zone, neutral zone characteristics, symmetry, conjugacy, waveforms, frequencies, and foveation times. RESULTS: Ages ranged from 3 to 6.5 months (average 4.9 months). 15 patients (56%) had abnormal vision for age, nine (33%) had strabismus, five (19%) had an anomalous head posture, 13 (48%) had oculographic null and neutral positions, nine (33%) had binocular asymmetry, and only two showed consistent dysconjugacy. Average binocular frequency was 3.3 Hz, monocular frequency 6.6 Hz. Average foveation periods were longer and more "jerk" wave forms were observed in those patients with normal vision. CONCLUSIONS: Common clinical characteristics and eye movement waveforms of INS begin in the first few months of infancy and waveform analysis at this time may help with both diagnosis and visual status.
Asunto(s)
Movimientos Oculares , Nistagmo Congénito/fisiopatología , Trastornos de la Visión/fisiopatología , Femenino , Movimientos de la Cabeza , Humanos , Lactante , Masculino , Nistagmo Congénito/diagnóstico , Síndrome , Agudeza VisualRESUMEN
PURPOSE: Limbal dermoids usually involve corneal stroma and more rarely might extend into the anterior chamber. Depending on the size and amount of penetration of the lesion, different therapeutic approaches are indicated. Depth information is difficult to obtain by slit-lamp examination because the structure is opaque. We investigated the use of ultrasound biomicroscopic (UBM) examination for surgical planning in limbal dermoids. METHODS: The UBM (Zeiss Humphrey) with its 50-MHz probe was used for preoperative evaluation of the depth of penetration in two cases of infantile limbal dermoid. Histology specimens of the lesion corresponding to the UBM images were obtained. RESULTS: UBM was able to distinguish normal cornea from the more sonolucent lesion. Presence or absence of Descemet's membrane could be identified. Depth of involvement of limbal dermoids could be assessed. CONCLUSION: UBM is able to assess depth involvement of opaque corneal lesions such as limbal dermoids. Because planning of the surgical approach in these cases is facilitated by preoperative knowledge about the depth of penetration of these opaque lesions, UBM can be regarded as a helpful tool in the clinical management.
Asunto(s)
Enfermedades de la Córnea/diagnóstico por imagen , Quiste Dermoide/diagnóstico por imagen , Neoplasias del Ojo/diagnóstico por imagen , Queratoplastia Penetrante , Limbo de la Córnea/diagnóstico por imagen , Preescolar , Enfermedades de la Córnea/patología , Enfermedades de la Córnea/cirugía , Quiste Dermoide/patología , Quiste Dermoide/cirugía , Neoplasias del Ojo/patología , Neoplasias del Ojo/cirugía , Humanos , Limbo de la Córnea/patología , Limbo de la Córnea/cirugía , Fotomicrografía , UltrasonografíaRESUMEN
BACKGROUND AND PURPOSE: We studied children with nystagmus who also had anomalous head postures and strabismus to determine the etiology of the conditions and present a diagnostic clinical algorithm. METHODS: The patients for this study were among the 560 patients evaluated in the ocular motor neurophysiology laboratory between the years 1991 and 1997. Clinical characteristics, infrared oculography data, and medical and surgical treatments were entered into a database for analysis. Oculography was performed on all patients according to a standard protocol, and data were stored and analyzed off-line. Etiology of anomalous head posture was determined with both clinical and oculography information. RESULTS: Thirty-seven children are the subjects of this report. The etiology of anomalous head posture was a "gaze null" due to congenital nystagmus in 23 (62%) patients, an "adduction null" due to manifest latent nystagmus in 12 (32%) patients, spasmus nutans in 1 (3%) patient, and strabismus in 1 (3%) patient. The patients' ages ranged from 9 months to 12 years and averaged 4.4 years. Sixty-nine percent were male patients. Nineteen (63%) of 30 patients had abnormal recognition (linear optotype) acuity in at least 1 eye on monocular cover; the recognition remained abnormal in 5 (17%) of 30 patients under binocular conditions. Thirty percent of patients had amblyopia, 16% had some structural disease of the eyes, 22% had some systemic syndrome or abnormality, 57% had a significant refractive error, and 27% had some ability to fuse. CONCLUSIONS: The major etiology for anomalous head posture in these patients was to adopt a gaze null due to congenital nystagmus (62% of patients) regardless of the direction of their anomalous head posture or type of strabismus. Moving the fixing eye as the first step for the anomalous head posture, combined with moving the nonfixing eye for the resulting strabismus may help treat these patients.
Asunto(s)
Movimientos de la Cabeza , Nistagmo Congénito/complicaciones , Trastornos de la Motilidad Ocular/etiología , Postura , Estrabismo/complicaciones , Algoritmos , Niño , Preescolar , Diagnóstico Diferencial , Electrooculografía , Movimientos Oculares/fisiología , Femenino , Humanos , Lactante , Masculino , Nistagmo Congénito/fisiopatología , Trastornos de la Motilidad Ocular/diagnóstico , Trastornos de la Motilidad Ocular/fisiopatología , Músculos Oculomotores/fisiopatología , Estudios Retrospectivos , Estrabismo/fisiopatologíaRESUMEN
PURPOSE: The purpose of this study was to identify the clinical and ocular motility characteristics of congenital nystagmus and to establish the range of waveforms present in infancy. BACKGROUND: The clinical condition of congenital nystagmus usually begins in infancy and may or may not be associated with visual sensory system abnormalities. Little is known about its specific waveforms in infancy or their relationship to the developing visual system. METHODS: Forty-three infants with involuntary ocular oscillations typical of congenital nystagmus were included in this analysis. They were evaluated both clinically and with motility recordings. Eye movement analysis was performed off line from both chart recordings and computer analysis of digitized data. Variables analyzed included age, sex, vision, ocular abnormalities, head position, null-zone or neutral-zone characteristics, symmetry, conjugacy, waveforms, frequencies, foveation times, and responses to convergence and to monocular cover. RESULTS: Patient ages ranged from 3 to 18 months (average, 9.2 months). Seventeen patients (40%) had abnormal vision, 3 had a positive family history of nystagmus, 11 had strabismus, 16 (37%) had a head posture, 26 (60%) had null and neutral positions, 14 (33%) had binocular asymmetry, and all were horizontally conjugate. Average binocular frequency was 2.8 Hz, and average monocular frequency was 4.6 Hz. The waveforms were both jerk and pendular; average foveation periods in patients with normal vision were more than twice as long as those in patients with abnormal vision. CONCLUSIONS: Common clinical characteristics and eye-movement waveforms of congenital nystagmus begin in infancy, and waveform analysis at this time helps with both diagnosis and visual status.
Asunto(s)
Movimientos Oculares/fisiología , Nistagmo Patológico/congénito , Músculos Oculomotores/fisiopatología , Electrooculografía , Femenino , Humanos , Lactante , Masculino , Nistagmo Patológico/diagnóstico , Nistagmo Patológico/fisiopatología , Estudios Retrospectivos , Visión Binocular , Agudeza VisualRESUMEN
PURPOSE: Our purpose was to establish whether comitance was a common or uncommon finding in children with esodeviation associated with a neurologic insult. METHODS: A retrospective chart review was performed of children with acquired esodeviation associated with an identifiable neurologic insult. RESULTS: Examinations of 30 children seen over a 2-year period were analyzed. Twenty-two (73%) had brain tumors. Twelve (40%) had comitant esodeviation, and the other 18 (60%) had incomitant measurements. Of the patients with comitant esodeviation, 6 had normal abduction OU (two after recovery from bilateral sixth nerve palsies), and 6 had mild or minimal abduction deficits. Moderate or severe abduction deficits were associated with incomitant measurements. CONCLUSIONS: Comitant esodeviation can be common in children with identifiable neurologic insults.
Asunto(s)
Neoplasias Encefálicas/complicaciones , Esotropía/etiología , Acomodación Ocular , Adolescente , Encefalopatías/complicaciones , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios RetrospectivosRESUMEN
PURPOSE: Human eye-movement recordings have documented that surgical treatment of congenital nystagmus (CN) also produces a broadening of the null zone and changes in foveation that allow increased acuity. We used the achiasmatic Belgian sheepdog, a spontaneously occurring animal model of human CN and see-saw nystagmus (SSN), to test the hypothesis that changes induced by surgical interruption of the extraocular muscle afference without a change in muscle-length tension could damp both oscillations. METHODS: An achiasmatic dog with CN and SSN underwent videotaping and infrared oculography in a sling apparatus and head restraints before and after all extraocular muscles (stage 1: 4 horizontal rectus muscles and stage 2 [4 months later]: 4 vertical rectus muscles and 4 oblique muscles) were surgically tenotomized and immediately reattached at their original insertions. RESULTS: The dog had immediate and persistent visible, behavioral, and oculographic changes after each stage of this new procedure. These included damped CN and SSN, increased ability to maintain fixation, and increased periods of maintaining the target image on the area centralis over a broad range of gaze angles. CONCLUSIONS: Severing and reattaching the tendons of the extraocular muscles affect some as-yet-unknown combination of central nervous system processes producing the above results. This new procedure may prove effective in patients with CN with either no null, a null at primary position, or a time-varying null (due to asymmetric, (a)periodic, alternating nystagmus). We infer from our results in an achiasmatic dog that tenotomy is the probable cause of the damping documented in human CN after Anderson-Kestenbaum procedures and should also damp CN and SSN in achiasma in humans. It may also prove useful in acquired nystagmus to reduce oscillopsia. The success of tenotomy in damping nystagmus in this animal suggests that the proprioceptive feedback loop has a more important role in ocular-motor control than has been appreciated. Finally, we propose a modified bimedial recession procedure, on the basis of the damping effects of tenotomy.
Asunto(s)
Modelos Animales de Enfermedad , Nistagmo Patológico/congénito , Nistagmo Patológico/cirugía , Quiasma Óptico/anomalías , Propiocepción/fisiología , Tendones/cirugía , Animales , Conducta Animal/fisiología , Perros , Movimientos Oculares/fisiología , Fijación Ocular , Nistagmo Patológico/fisiopatología , Músculos Oculomotores/cirugía , Seguimiento Ocular Uniforme/fisiología , Reflejo Vestibuloocular/fisiología , Tendones/fisiopatologíaRESUMEN
BACKGROUND: Strabismus is present in approximately 4% of the population with most forms becoming clinically evident in infancy and childhood. Adult strabismus, including that resulting from recurrent childhood deviations, varies in etiology, presentation, symptomatology, and response to treatment. This report is intended to prospectively characterize adults who required surgical correction of their strabismic deviation. METHODS: Beginning in 1991, a prospective computerized database was collected that contained all clinical, laboratory, and surgical information on the adult ocular motility service at the Scheie Eye Institute and The Children's Hospital of Philadelphia (Philadelphia, Pa). Analysis of those patients who underwent surgical correction of their strabismus is included in this report. Demography, clinical characteristics, and surgical procedures including results were analyzed separately in adults with their strabismus beginning before visual maturation (BVM) (9 years of age) and after visual maturation (AVM). RESULTS: A minimum of 6 months and average of 1.8 years follow up is reported on 262 procedures in 255 patients with an average age of 37 between January 1991 and January 1996. Sixty-two percent of patients had their strabismus onset BVM. Fifty-one percent of BVM patients and 80% of AVM patients had incomitant deviations. Adjustable suture surgery was performed on 97% of all patients, with 28% of BVM and 57% of AVM patients having multiplanar surgery. Successful motor alignment was achieved in 85% of all patients after one surgical procedure. Sensory success was achieved in 81% of all AVM patients and 25% of all BVM patients. Subjective success was 94% in both groups of patients. CONCLUSIONS: Numerous differences exist between childhood and adult strabismus characteristics and response to surgery. Although strabismus surgery is effective, differences in results reflect the varied physiology regarding etiology, pathophysiology, and symptomology. Classification into AVM and BVM groups will provide continued clarity for future studies.