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Evaluacin oftlmica del paciente peditricoMR2 Eda Donayre RodrguezHAMADesarrollo embrionario

El ojo se desarrolla a partir de tres fuentes:neuroectodermodel cerebro anterior,ectodermo de superficiede la cabeza ymesodermoque se ubica en esta capas(fig. 18-1).Los primordios de las partes neurales del ojo, son evidentes al inicio de la cuarta semana, cuando lossurcos pticos(hendiduras pticas) se convierten en los pliegues neurales en el extremo craneal del embrin (fig. 18-1A).

Figura 18-1. Dibujos que ilustran los estadios sucesivos en el desarrollo del ojo4ss

Las vesculas pticas se unen a los lados de la cabeza e inducen al ectodermo de superficie relacionado con ellas, a formar engrosamientos que se denominanplcodas del cristalino(fig. 18-1B). Entre tanto, las vesculas pticos se invaginan para formarcpulas pticasde doble pared (fig. 18-1C). Las invaginaciones tambin involucran las superficies ventrales de los tallos pticos, donde forman surcos lineales llamadosfisuras pticas(fig. 18-1C y E). Las cpulas y fisuras pticas, se llenan con mesnquima vascular a partir del cual se forman laarteria y vena hialoideas.La arteria hialoidea riega al cristalino en desarrollo y la capa interna de la cpula ptica (fig. 18-1E yF)

Retina.-La retina se deriva de las paredes de la cpula ptica. La mayor parte de lacapa internase engruesa para formar laretina neural(fig. 18-2).Lacapa externapermanece bastante delgada y forma elepitelio pigmentado de la retina.La cavidad original de la cpula ptica se oblitera mientras se fusionan las capas internas y externas (fig. 18-2C), pero esta adherencia no es firme. Como consecuencia un golpe en el ojo puede causar separacin de la retina neural del epitelio pigmentado de la retina, lesin conocida en clnica comodesprendimiento de la retina.En su parte anterior, las capas de la cpula ptica permanecen delgadas y forman laparte no visual de la retina. Las partes proximales de los vasos hialoideos, forman laarteria y venas centrales de la retina .Las partes distales de dichas vasos desaparecen antes del nacimiento (fig. 18-2C).Retina neuralEpit pigment de la retinaSe oblitera, no es firme, desprendimiento de ret.A y V centrales de la retinaNervio ptico.-Cada uno est formado del tallo pednculo ptico de fibras nerviosas de la retina (fig. 18-1D y F). Los axones de las clulas en la capa superficial de la retina neural, crecen en direccin proximal dentro de la pared del tallo ptico hacia el cerebro. A medida de que esto ocurre, la cavidad del tallo ptico est obliterada por las diversas fibras nerviosas a partir de la retina hacia el nervio ptico (fig. 18-1D y F, 18-2C). Lamielinizacin de los nervios pticosse inicia en el periodo fetal tardo y se completa alrededor de la dcima semana despus del nacimiento.

Cuerpo vtreo.-Esta masa gelatinosa se deriva del mesnquima que entra en la cpula ptica mientras se esta formando (figs. 18-1C y 18-2B). Parte delhumor vtreo, el componente lquido del cuerpo vtreo se podr derivar a partir de la pared interna de la cpula ptica, en lo particular de la parte que forma el epitelio del cuerpo ciliar.

MesnquimaPrpados.-Estas estructuras accesorias del ojo sedesarrollan de pliegues del ectodermo de la superficieque se forman por encima y debajo de la crnea en crecimiento (fig. 18-2A y B). El mesnquima de los prpados en desarrollo, forma su tejido conectivo y lasplacas tarsales.Los prpados crecen uno hacia el otro y se fusionan durante la octava semana permanecen cerrado hasta cerca de la semana 26.

anoftalmia

Coloboma

Ptosis parp

1. Recto superior: III2. Recto inferior: III3. Recto interno: III4. Recto externo: VI tambin llamado nervio abducens.5. Msculo oblicuo superior del ojo: IV sup-int6. Msculo oblicuo inferior del ojo: III7. El msculo elevador del prpado superior es una prolongacin de fibras del recto superior que se inserta por la parte anterior al prpado y por detrs al anillo tendinoso. IIIEl esfnter pupilar y el cuerpo ciliar estn inervados por el nervio oculomotor. IIIInervacin de la musculatura extrnseca del globo ocular

Desarrollo Visual y evaluacion oftalmologica

Crecimiento y desarrollo visualRN a trmino: 65% tamao de adulto.Crecimiento rpido dentro del 1er ao y desacelera hasta la 3er ao, an < crecimiento hasta la pubertad.RN: segmento anterior > segmento posterior ambos en la estructura: ms esfrico

Crecimiento y desarrollo visualEl iris:Celeste o ligeramente gris al nacer, atraviesa cambios progresivos de color debido a la pigmentacin del estroma, incrementa a los 6 meses de vida.PupilasRN: Pequeas y difciles de dilatar. Remanentes de la membrana pupilar(cpsula vascular anterior) son evidentes en el examen con el oftalmoscopio como telaraa (en pretrminos).LenteRN: esfrico que en el adulto, poder de refraccin compensa tamao del globo ocular. >densidad y > resistencia para cambiar de posicin en el acomodamiento.Crece a travs de la vida

Crecimiento y desarrollo visualInfante: esclera es ms translucente y azulado.La crnea: 10mm en RN----12 mm a los 2 , curvatura se tiende a aplanar con cambios en el poder refractivo del ojo.Transparente.Prematuros tienen halo opalescente.La cmara anterior aparece superficial y las estructuras de ngulo importantes para el mantenimiento de la presin intraocular, debe atravesar difereciacin luego del nacimiento.

The eye of a normal full-term infant at birth is approximately 65% of adult size. Postnatal growth is maximal during the 1st yr, proceeds at a rapid but decelerating rate until the 3rd yr, and continues at a slower rate thereafter until puberty, after which little change occurs. The anterior structures of the eye are relatively large at birth but thereafter grow proportionately less than the posterior structures. This results in a progressive change in the shape of the globe; it becomes more spherical.In an infant, the sclera is thin and translucent, with a bluish tinge. The cornea is relatively large in newborns (averaging 10mm) and attains adult size (nearly 12mm) by the age of 2yr or earlier. Its curvature tends to flatten with age, with progressive change in the refractive properties of the eye. A normal cornea is perfectly clear. In infants born prematurely, the cornea may have a transient opalescent haze. The anterior chamber in a newborn appears shallow, and the angle structures, important in the maintenance of normal intraocular pressure, must undergo further differentiation after birth. The iris, typically light blue or gray at birth in white children, undergoes progressive change of color as the pigmentation of the stroma increases in the first 6 months of life. The pupils of a newborn infant tend to be small and are often difficult to dilate. Remnants of the pupillary membrane (anterior vascular capsule) are often evident on ophthalmoscopic examination, appearing as cobweb-like lines crossing the pupillary aperture, especially in preterm infants.The lens of a newborn infant is more spherical than that of an adult; its greater refractive power helps to compensate for the relative shortness of the young eye. The lens continues to grow throughout life; new fibers added to the periphery continually push older fibers toward the center of the lens. With age, the lens becomes progressively denser and more resistant to change of shape during accommodation.

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Remanentes del sistema vascular primitivo hialoideo pueden verse como gusanillos proyectndose del disco (Bergmeister papilla) o como una fina hebra del vtreo, en algunos casos slo un pequeo punto (Mittendorf dot) que se mantiene en el aspecto posterior de la cpsula del lente.

Prematuro de 30 ss.. EG. PN :750 gr. Factores de riesgo prenatales asociados: crecimiento intrauterino retrasado , prdida de bienestar fetal. Nacimiento por Cesrea. Patologa sistmica perinatal: Hemorragia Intraventricular grado I, trombopenia y anemia multifactorial.En el screening ROP a la cuarta semana de vida, se detecta Retinopata grado 2 en Zona II sin enfermedad Plus, segn Clasificacin Internacional de ROP (ICROP).Adems se observan extensas HR en polo posterior, alejadas de las lesiones por ROP, compatibles con HRRN (Fig.1 y 2). Al no existir trauma obsttrico, la causa se relacion con la anoxia perinatal, sin descartar la trombopenia como factor de riesgo aadido.Cabeza del nervio ptico: rosado---ligeramente plido o grisceo4-6m la apariencia del fondo = ojo maduro.Hemorragias retinianas superficiales pueden observarse en muchos recin nacidos, se autoreabsorben en 2 semanas.Hemorragias conjuntivales pueden ocurrir al nacer y reabsorberse sin consecuencias.

El fondo de ojo del RN es < pigmentadoCoroides es altamente visible y la pigmentacin de la retina presenta un patrn moteado.Mcula: el reflejo de luz de la fovea es definido y a veces no aparece.La retina perifrica plida o griscea con vasculatura inmadura (prematuros).

Fondo de ojo: focos mltiples de coriorretinitis porCandida albicansCrecimiento y desarrollo visualRefraccin:El estado de refraccin en cualquier momento de la vida depende de muchos factores: Tamao del ojoEstado de los lentesCurvatura de la crneaLos RN tienden a mantener sus ojos cerrados ms tiempo, pero normalmente los RN pueden ver, responden a cambios en la iluminacin y fijar puntos de contraste. La agudeza visualRN: 20/400Uno de los primeros estmulos es la cara materna durante la alimentacin.2 ss: inters por objetos de ms tamao.8-10 ss: siguen objeto en un rango de 1803 : agudeza visual mejora 20/30----20/20Muchos infantes tienen incoordinacin en el movimiento ocular y alineacin durante los das y semanas, pero coordinacin propia se debe alcanzar a los 3-6 meses o antes, de persistir debera ser evaluado.

An infant's eye is somewhat hyperopic (farsighted). The general trend is for hyperopia to increase from birth until 7yr of age. Thereafter, the level of hyperopia tends to decrease rapidly until age 14yr. Elimination of the hyperopic state can occur during this time. If the process continues, myopia (nearsightedness) develops. A slower continuation of the decrease in hyperopia, or increase in myopia, continues into the 3rd decade of life. The refractive state at any time in life depends on the net effect of many factors: the size of the eye, the state of the lens, and the curvature of the cornea.Newborn infants tend to keep their eyes closed much of the time, but normal newborns can see, respond to changes in illumination, and fixate points of contrast. The visual acuity in newborns is estimated to be approximately 20/400. One of the earliest responses to a formed visual stimulus is an infant's regard for the mother's face, evident especially during feeding. By 2wk of age, an infant shows more-sustained interest in large objects, and by 8-10wk of age, a normal infant can follow an object through an arc of 180 degrees. The acuity improves rapidly and can reach 20/30-20/20 by the age of 2-3yr.Many normal infants have imperfect coordination of the eye movements and alignment during the early days and weeks, but proper coordination should be achieved by 3-6mo of age, usually sooner. Persistent deviation of an eye in an infant requires evaluation.Tears often are not present with crying until after 1-3mo of age. Preterm infants have reduced reflex and basal tear secretion, which can allow topically applied medications to become concentrated and lead to rapid drying of their corneas

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Las lgrimas no estan presentes mientras llora hasta los 1-3 meses. Pretrminos pueden presentar secrecin y reflejo de secrecin lagrimal.

El ojo del infante es algo hiperopico (hipermtrope)La hipermetropa desde el nacimiento hasta los 7 aos hasta los 14 aos, tiempo en que la hipermetropa tiende a desaparecer.NO CORRIGE: MIOPIA que continua hasta los 30 aosExamen visualDe rutina al RNEn cada evaluacin de nio sanoEvaluacin por oftalmlogo si aparece alguna alteracin o nios de alto riesgo (prematuros, malf craneofaciales, defectos oculares genticos, enf sistemicas.Examen bsicoAgudeza del campo visualCondicion de las pupilasMotilidad ocular y alineamientoExamen ocular generalExamen con oftalmoscopioFondo de ojoSegun indicacin del oftalmlogoBiomicroscopia (examen con lmpara de hendidura)Refraccin cicloplgicaTonometraProcedimientos especiales:Examen ultrasnicoAngiografa flourescenteELectroretinografiaPrueba de potenciales visuales evocadosExamination of the eyes is a routine part of the periodic pediatric assessment beginning in the newborn period. The primary care physician is very important in detecting both obvious and insidious asymptomatic eye diseases. Screening by lay persons in schools and community programs can also be effective in detecting problems early. The best method of screening (ages 3-5yrs) is currently being investigated. The American Academy of Ophthalmology recommend preschool vision screening as a means of reducing preventable visual loss (Table 611-1). This testing should also be done by pediatricians during well child visits. Children should be examined by an ophthalmologist whenever a significant ocular abnormality or vision defect is noted or suspected. Children who are at high risk of ophthalmologic problems, such as genetically inherited ocular conditions and various systemic disorders, should also be examined by an ophthalmologist.Basic examination, whether done by a pediatrician or an ophthalmologist, must include evaluation of visual acuity and the visual fields, assessment of the pupils, ocular motility and alignment, a general external examination, and an ophthalmoscopic examination of the media and fundi. When indicated, biomicroscopy (slit-lamp examination), cycloplegic refraction, and tonometry are performed by an ophthalmologist. Special diagnostic procedures, such as ultrasonic examination, fluorescein angiography, electroretinography, or visual evoked response (VER) testing, are also indicated for specific conditions.

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Committee on Practice and Ambulatory Medicine, Section on Ophthalmology; American Association of Certified Orthoptists; American Association for Pediatric Ophthalmology and Strabismus; American Academy of Ophthalmology: Eye examination in infants, children, and young adults by pediatricians, Pediatrics 111:902907, 2003

Committee on Practice and Ambulatory Medicine, Section on Ophthalmology; American Association of Certified Orthoptists; American Association for Pediatric Ophthalmology and Strabismus; American Academy of Ophthalmology: Eye examination in infants, children, and young adults by pediatricians, Pediatrics 111:902907, 2003Agudeza visualDepende de la edad del pcte y de la colaboracin del mismoInfantes: habilidad para la fijacin y seguimiento de un objetivo (desde las 6 semanas)Sentar al infante en el regazo del cuidadorMover objeto de interes de lado a lado( I-D)Ver si hay seguimiento del objetoLuego ocluir un ojo a la vez con el pulgarMovimiento facial ms atractivoSe debe recordar que nios con pobre visin pueden seguir un objeto grande sin aparente dificultad especialmente si un ojo es afectadoEvaluacin de agudeza visual ms objetiva cuando el nio tiene 2,5-3: cartillas para evaluacin visual, evaluando cada ojo por separadoAcompaar en todo momento al menor y darle confianza.

There are many tests of visual acuity. Which test is used depends on a child's age and ability to cooperate, as well as a clinician's preference and experience with each test. The most common visual acuity test in infants is an assessment of their ability to fixate and follow a target. If appropriate targets are used, this reflex can be demonstrated by about 6 weeks of age. The test is performed by seating the child comfortably in the caretaker's lap. The object of visual interest, usually a bright-colored toy, is slowly moved to the right and to the left. The examiner observes whether the infant's eyes turn toward the object and follow its movements. The examiner can use a thumb to occlude one of the infant's eyes and test each eye separately. Although a sound-producing object might compromise the purity of the visual stimulus, in practice, toys that squeak or rattle heighten an infant's awareness and interest in the test.The human face is a better target than test objects. The examiner can exploit this by moving his or her face slowly in front of the infant's face. If the appropriate following movements are not elicited, the test should be repeated with the caretaker's face as the test stimulus. It should be remembered that even children with poor vision can follow a large object without apparent difficulty, especially if only one eye is affected.An objective measurement of visual acuity is usually possible when children reach 2.5-3 years of age. Children this age are tested using a schematic picture or other illiterate eye chart. Each eye should be tested separately. It is essential to prevent peeking. The examiner should hold the occluder in place and observe the child throughout the test. The child should be reassured and encouraged throughout the test because many children are intimidated by the procedure and fear a bad grade or punishment for errors.

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HOTV test3-6mPreescolares-6 aos

Lea optotypes

Allen test

Agudeza visualEl E test es el ms usado en el preescolarD-I es ms confuso que arriba abajoSe puede realizar sin problemas en nios de 3-4 aosTabla de agudeza de Snellen se puede usar desde 5-6 aos si el nio sabe las letras.Agudeza visual20/40 : 3 aos20/30: 4 aos20/20: 5 aos

The E test, in which a child points in the direction of the letter, is the most widely used visual acuity test for preschool children. Right-left presentations are more confusing than up-down presentations. With pretest practice, this test can be performed by most children 3-4 years of age.An adult-type Snellen acuity chart can be used at about 5 or 6 years of age if the child knows letters. An acuity of 20/40 is generally accepted as normal for 3yr old children. At 4yr of age, 20/30 is typical. By 5 or 6 years of age, most children attain 20/20 vision.Optokinetic nystagmus (the response to a sequence of moving targets; railroad nystagmus) can also be used to assess vision; this can be calibrated by targets of various sizes (stripes or dots) or by a rotating drum at specified distances. The VER, an electrophysiologic method of evaluating the response to light and special visual stimuli, such as calibrated stripes or a checkerboard pattern, can also be used to study visual function in selected cases. Preferential looking tests are also used for evaluating vision in infants and children who cannot respond to standard acuity tests. This is a behavioral technique based on the observation that given a choice, an infant prefers to look at patterned rather than unpatterned stimuli. Because these tests require the presence of a skilled examiner, their use is often limited to research protocols involving preverbal children.

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Childs attention is obtained with a toy

Examiner covers the left eye and observes the childs ability to maintain fixation with the right eye.Fijacin (cntrica o excentrica)del ojoCSM: Central SteadyMaintained Estrabismo: cambia la fijacin del ojoBaja visin: genera ansiedad cuando se cubre el ojo sano

Imgenes estimulantes en un rango de 6 ciclos por seg. en frente de los ojos del paciente.Se colocan electrodos en el lbulo occipitalPotenciales de agudeza visual: un mtodo eletrofisiolgico para evaluar la respuesta a la luz y estmulo visual especial.

Snellen

Nistagmus optokinetico (la respuesta a la secuencia de movimientos riel de tren nistagmus) se puede usar para la evaluacin de la visin; por un tambor giratorio.Evaluacin de campo visualExamen de campo visual (permetro y escotometra) se puede realizar en el nio en etapa escolar.El examinador puede confiar en tcnicas de confrontacin y visin cuenta dedos en cuadrantes del campo visual..

Like visual acuity testing, visual field assessment must be geared to a child's age and abilities. Formal visual field examination (perimetry and scotometry) can often be accomplished in school-aged children. The examiner must often rely on confrontation techniques and finger counting in quadrants of the visual field. In many children, only testing by attraction can be accomplished; the examiner observes a child's response to familiar objects brought into each of the four quadrants of the visual field of each eye in turn. The child's bottle, a favorite toy, and lollipops are particularly effective attention-getting items. These gross methods can often detect diagnostically significant field changes such as the bitemporal hemianopia of a chiasmal lesion or the homonymous hemianopia of a cerebral lesion.

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Observar como atrae el objeto de su inters.Estos mtodos groseros pueden detectar cambios en el campo visual como hemianopsia bitemporal o lesiones quiasmticas; hemianopsia homnima de una lesin cerebralPrueba de visin de colorSlo cuando pueda reconocer los colores.Padres preocupados por dificultad en elegir o mencionar el color adecuado. Es muy raro la ceguera de colores y no compatible con la vision normal.Defectos en la visin de colores es comn en varones.Acromaptosia un defecto en la visin total de colores con anormal agudeza visual, nistagmus, fotofobiaSe encuentra ocasionalmente. Un cambio en la discriminacin de colores puede ser signo de dao del nervio ptico o enfermedad de la retina.Color vision testing can be accomplished whenever a child is able to name or trace the test symbols; these may be numbers, Xs, Os, triangles, or other symbols. Color vision testing is not often necessary in young children, but parents sometimes request it, particularly if their child seems to be slow in learning colors. Parents are often reassured to know that color-deficient children do not misname colors and that true color blindness is very rare and not compatible with normal vision. Defective color vision is common in male patients but is rare in female patients. Achromatopsia, a total color vision defect with subnormal visual acuity, nystagmus, and photophobia, is encountered occasionally. A change in color discrimination can be a sign of optic nerve or retinal disease.

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La prueba consiste en una serie de cartas de colores, llamadasCartas de Ishihara, cada una de las cuales contiene crculos de puntos de colores y tamaos aleatoriosExamen de la pupilaReaccin directa y consensual a la luzReaccin de la mirada cercanaRespuesta la iluminacin reducidaNotando el tamao y dimetro pupilar en todas estas condiciones.La prueba de la linterna de balanceo es especialmente til para la deteccin de defectos aferentes prequiasmticos unilaterales o asimtricos en los nios.

Examination of the pupils includes evaluation of both, the direct and consensual reactions to light, the reaction on near gaze, and the response to reduced illumination, noting the size and symmetry of the pupils under all conditions. Special care must be taken to differentiate the reaction to light from the reaction to near gaze. A child's natural tendency is to look directly at the approaching light, inducing the near gaze reflex when one is attempting to test only the reaction to light; accordingly, every effort must be made to control fixation. The swinging flashlight test is especially useful for detecting unilateral or asymmetric prechiasmatic afferent defects in children (see Marcus Gunn Pupil section in Chapter 614).

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Reflejo rojo

Cuarto oscuroAl mismo nivel del pcte30-45 cm.

Motilidad ocularHacer seguir un objeto en diversas posicionesMovimiento individual y de ambos ojos (mov. conjugados y de convergencia)La alineacin es juzgado por el reflejo corneal a la luz y por la respuesta a la oclusin alternada de cada ojo.

a laluz cornealOcular motility is tested by having a child follow an object into the various positions of gaze. Movements of each eye individually (ductions) and of the two eyes together (versions, conjugate movements, and convergence) are assessed. Alignment is judged by the symmetry of the corneal light reflexes and by the response to alternate occlusion of each eye (see discussion on cover tests for strabismus in Chapter 615).

46Visin Binocular Determinar el grado de vision binocular. Test Titmus es una serie de imgenes tridimensionales que les muestra al nio mientras ve con unos lentes polaroid.El nivel de dificultad en el cual estas imgenes pueden ser detectadas se correlaciona con el grado de visin binocular que est presente.A determination of the degree of binocular vision is commonly performed by an ophthalmologist. The Titmus test is probably the most commonly used test; a series of three-dimensional images are shown to the child while he or she wears a set of Polaroid glasses. The level of difficulty with which these images can be detected correlates with the degree of binocular vision that is present. Other tests may also be used to detect the presence of abnormal binocular adaptations secondary to poor vision or strabismus.

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Agudeza estreo Randon-dot-E stereo test

40cmCambiar cartas en 5 oportunidades3 a 8 aosHabilidad de percepcin de profundidad, ambos ojos deben trabajar juntos.Ambos ojos funcionan: cerebro hace 1 imagenFalla: dificultad para ver profundidadExamen externoInspeccin general en un rea de buena iluminacin, notando el tamao, forma, simetra de las rbitas, posicin y movimientos de los prpados, posicin y simetra de los globos.Deteccin: asimetra de rbitas, masas en prpados, proptosis(exoftalmos), pulsaciones anormales.Palpacin es importante en detectar masas de prpados y orbitas

The external examination begins with general inspection in good illumination noting size, shape, and symmetry of the orbits; position and movement of the lids; and position and symmetry of the globes. Viewing the eyes and lids from above aids in detecting orbital asymmetry, lid masses, proptosis (exophthalmos), and abnormal pulsations. Palpation is also important in detecting orbital and lid masses.The lacrimal apparatus is assessed by looking for evidence of tear deficiency, overflow of tears (epiphora), erythema, and swelling in the region of the tear sac or gland. The sac is massaged to check for reflux when obstruction is suspected. The presence and position of the puncta are also checked.The lids and conjunctivae are specifically examined for focal lesions, foreign bodies, and inflammatory signs; loss and maldirection of lashes should also be noted. When necessary, the lids can be everted in the following manner: (1) instruct the patient to look down; (2) grasp the lashes of the patient's upper lid between the thumb and index finger of one hand; (3) place a probe, a cotton-tipped applicator, or the thumb of the other hand at the upper margin of the tarsal plate; and (4) pull the lid down and outward, everting it over the probe, using the instrument as a fulcrum. Foreign bodies commonly lodge in the concavity just above the lid margin and are exposed only by fully everting the lid.The anterior segment of the eye is then evaluated with oblique focal illumination, noting the luster and clarity of the cornea, the depth and clarity of the anterior chamber, and the features of the iris. Transillumination of the anterior segment aids in detecting opacities and in demonstrating atrophy or hypopigmentation of the iris; these latter signs are important when ocular albinism is suspected. When necessary, fluorescein dye can be used to aid in diagnosing abrasions, ulcerations, and foreign bodies.

50El aparato lagrimal: bsqueda de deficiencia lacrimal, exceso de lgrimas (epfora), eritema, edema de la glndula o saco lacrimal. Se masajea el saco para ver si hay reflujo cuando se sospecha de obstruccin de la salida del conducto lacrimal.Prpados y conjuntiva: lesiones focales, signos inflamatorios, prdida y maldireccin de las pestaas. Eversin de los prpados.Segmento anterior del ojo debe ser evaluado: con iluminacin focal oblicua, notando la claridad de la crnea de la cmara anterior y el iris.

Biomicroscopy (Slit-Lamp Examination)Magnificaciones de varias estructuras a travs de la crnea, humor acuoso, lente y vtreobiomicroscopia es crucial en trauma y en el examen de iritis.Ayuda al dx de enfermedades metablicas de la niez

The slit-lamp examination provides a highly magnified view of the various structures of the eye and an optical section through the media of the eyethe cornea, aqueous humor, lens, and vitreous. Lesions can be identified and localized according to their depth within the eye; the resolution is sufficient to detect individual inflammatory cells in the aqueous and vitreous. With the addition of special lenses and prisms, the angle of the anterior chamber and regions of the fundus also can be examined with a slit lamp. Biomicroscopy is often crucial in trauma and in examining for iritis. It is also helpful in diagnosing many metabolic diseases of childhood.

53Fondo de Ojo(Ophthalmoscopy)Mejor con ojo dilatadoMidriticos de accin corta: Tropicamide (Mydriacyl) 0.5-1% and phenylephrine (Neo-Synephrine) 2.5% Seguros para la mayora de nios.Para nios ms pequeos, en menor concentracin.Se inicia con el disco y la mcula para puntos de referencia, evaluando los 4 cuadrantes, siguiendo el mayor grupo de vasos de la periferie.Ophthalmoscopy is best done with the pupil dilated unless there are neurologic or other contraindications. are recommended as mydriatics of short duration. These are safe for most children, but the possibility of adverse systemic effects must be recognized. For very small infants, more-dilute preparations may be advisable. Beginning with posterior landmarks, the disc and the macula, the four quadrants are systematically examined by following each of the major vessel groups to the periphery. More of the fundus can be seen if a child is directed to look up and down and to the right and left. Even with care, only a limited amount of the fundus can be seen with a direct or hand-held ophthalmoscope. For examination of the far periphery, an indirect ophthalmoscope is used, and full dilation of the pupil is essential.

54RefraccinDetermina el grado de refraccin del ojoGrado de vision de cercaVision de lejosAstigmatismoRetinoscopia provee la determinacin de la cantidad de correcin necesaria que se puede realizar en cualquier edad.En preescolares es mejor hacerlo con cicloplega.Refinamiento subjetiva de refraccin consiste en pedir a los pacientes de las preferencias en la fuerza y el eje de lentes correctivos; que se puede lograr en muchos nios en edad escolar. Refraccin y la determinacin de la agudeza visual con lentes correctivos apropiados en el lugar son pasos esenciales para decidir si un paciente tiene un defecto visual o ambliopa.Cmaras fotoanlisis ayudan al personal mdico auxiliar en la deteccin de errores refractivos anormales en los nios pre-verbales.La precisin y la utilidad prctica de estos dispositivos estn siendo todava investigadas.

A test of refraction determines the refractive state of the eye: the degree of nearsightedness, farsightedness, or astigmatism. Retinoscopy provides an objective determination of the amount of correction needed and can be performed at any age. In young children, it is best done with cycloplegia. Subjective refinement of refraction involves asking patients for preferences in the strength and axis of corrective lenses; it can be accomplished in many school-aged children. Refraction and determination of visual acuity with appropriate corrective lenses in place are essential steps in deciding whether a patient has a visual defect or amblyopia. Photoscreening cameras aid ancillary medical personnel in screening for abnormal refractive errors in preverbal children. The accuracy and practical usefulness of these devices are still being investigated.

55TonometraMedidas de presin intraocular tonometra; se puede llevar a cabo con un instrumento independiente porttil o por el mtodo de aplanacin con la lmpara de hendidura. Los mtodos alternativos son neumtica, electrnica o tonometra de rebote. Cuando es necesaria una medicin precisa de la presin en un nio que no puede cooperar, se puede llevar a cabo con sedacin o anestesia general. Una estimacin bruta de la presin puede hacerse mediante la palpacin del globo con los dedos ndices colocados lado a lado en la tapa superior por encima de la placa tarsal

Tonometry measures intraocular pressure; it may be performed with a portable, stand-alone instrument or by the applanation method with the slit lamp. Alternative methods are pneumatic, electronic, or rebound tonometry. When accurate measurement of the pressure is necessary in a child who cannot cooperate, it may be performed with sedation or general anesthesia. A gross estimate of pressure can be made by palpating the globe with the index fingers placed side by side on the upper lid above the tarsal plate

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