VIEWS: 1 PAGES: 7 POSTED ON: 4/26/2011
Answers Board Review- The Eye week of 3/29 (1) 2009-question 211 answer A-oral analgesic Corneal abrasions occur commonly in children as a result of vigorous rubbing of the eye or a foreign body. Symptoms are tearing, photophobia, and pain. The physical examination may reveal injection of the conjunctivae, copious clear discharge, or a dull corneal light reflex. It is important to perform fluorescein dye staining in children suspected of having a corneal abrasion. This dye stains the damaged cornea but is not taken up by intact corneal epithelium. The staining is seen best with a Wood lamp (Item C211), but large abrasions may be visible with regular white light or an ophthalmoscope. The presence of a linear abrasion, as described for the girl in the vignette, suggests the possibility of a retained foreign body underneath the eyelid, and care should be taken to evert the eyelid to evaluate for this. Topical anesthetic drops, such as tetracaine, may be used to facilitate the eye examination and may provide significant relief to the patient, but providing these for home use is not recommended because they may slow healing and mask persistence of symptoms. Oral analgesics usually are all that is needed to control pain while the abrasion heals. Topical nonsteroidal anti-inflammatory drops also may provide relief, but topical steroids are not indicated in the management of uncomplicated corneal abrasions (due to concerns about adverse effects on wound healing and exacerbation of coexisting viral infection). Antibiotic ointment may provide lubrication until the abrasion has healed, but the risk of secondary infection is low, so routine use of antibiotics is not needed. Patching does not speed the healing process and has been shown to interfere with activities of daily living; it no longer is recommended for routine care of simple corneal abrasions. Most corneal abrasions heal within 2 to 3 days, so if symptoms continue beyond this period, evaluation by an ophthalmologist is warranted to rule out secondary infection or retained foreign body. (2) 2007 question 182 answer E-spasmus nutans Nystagmus is an involuntary, rhythmic oscillation of both eyes (rarely one) in which at least one phase is slow. Nystagmus reflects a deficit in gaze holding mechanisms, analogous to brakes that no longer stop an automobile appropriately. Jerk nystagmus is characterized by a slow phase in one direction, usually back to central position, followed by a fast, compensatory movement in the opposite direction, back to the far lateral side. A few beats of jerk nystagmus in the horizontal plane are physiologic, or normal when a child gazes far laterally. Sustained nystagmus, especially if associated with other neurologic findings, is abnormal. The differential diagnosis includes drug toxicity, vestibular dysfunction, tumor, or infarction. Chiari malformations produce downbeating or vertical jerk nystagmus. Pendular nystagmus is defined as slow movements in both phases, with the eyes moving to and fro. Pendular nystagmus can be a sign of brainstem infarction, spinocerebellar degeneration, MS, or rarely seizure. Spasmus nutans is a benign, transient disorder without known cause that is characterized by pendular nystagmus, intermittent head tilt and nodding or titubating of the head as described for the girl in the vignette. The head tilt can be mistake as a muscular torticullis. The onset is between ages 1 and 3 years, most often in the first 12 postnatal months, with spontaneous resolution within 1 to 2 years. A glioma in the optic pathway can cause jerk or pendular nystagmus but it also produces loss of visual acuity or field and over time, optic atrophy. Phenytoin intoxication produces jerk nystagmus. Congenital nystagmus can have pendular to jerk movements that often are not noted until several months or years after birth, and it frequently is characterized by some loss of visual acuity. This disorder can be inheritied in variable pattern. Retinoblastoma at presentation does not produce nystagmus, but instead leukoria with loss of the red reflex. (3) 2007 113 answer D massage and cleansing Tears enter either the upper or lower punctum of the medial aspect of the eye and drain into the nasolacrimal duct (NLD). Among neonates, obstruction of the NLD frequently occurs at the site where the duct passes through the maxilla into the nose. Some 6% of newborns exhibit obstruction when the embryonic structures fail to fully canalize. NLD is observed with increased frequency in certain populations, including preterm infants and children who have Down syndrome. Signs of obstruction include pooling or overflow of tears, which may not be observed until normal tear production develops. Often, there is accumulation of mucoid materal at the medical canthus. Stasis of tears in the obstructed NLD results in conditions favorable for bacterial infection. Progression of infection can lead to cellulitis of the overlying soft tissue. Preferred management of the infant described in the vignette is to recommend massage overlying the NLD 2-3 times daily and cleansing of the lid as necessary. When the infection complicates the obstruction of the drainage system, instillation of a topical ophthalmic antibiotic is justified, but systemic antibiotics are not indicated. NLD obstruction typically resolves by 9-12 months of age. Persistence of symptoms beyond this time justifies referral to an ophthalmologist for possible probing of the NLD. For the patient in the vignette, the cornea is involved, and fluorescein staining would not be beneficial. Instillation of a topical ophthalmic corticosteroid is not indicated in the management of this disorder and is associated with significant risks. (4) 2007 198 answer A botulism Ptosis may be congenital or acquired. Congenital ptosis is associated with a wide variety of lid dysfunctions, may be unilateral or bilaterally, and may have a neural or muscular origin. Ptosis may arise from a congenital or new third new origin, with severe lid weakness and often associated with superior rectus weakness. Ptosis resulting from sympathetic dysfunction usually presents unilaterally, with no more than 2-3mm lid weakness. The responsible lesion arises anywhere along the course of the sympathetic pathway from the hypothalamus to the orbit. Such ptosis usually is accompanied by the miosis and anhidrosis (horner syndrome) and can be congenital or newly acquired. Neuromuscular causes for ptosis that have a new onset neuropathic or myopathic basis include MG, mitochondrial disease (chronic progressive external ophthalmoplegia) and toxin exposures such as botulism, dipetheria, tick paralysis, insecticides, and vincristine. The bilateral ptosis, combined with constipation and dimished reflexes all developing during the introduction of solid foods described for the infant in the vignette is classic for botulism. Congential ptosis would have been present since birth, and myasthenia produces variable ptosis, not seen in this baby. Most muscular dystropies, except myotonic dystrophy do not produce ptosis. Blepharophimosis syndrome is an AD condition that has a high penatrance, producing bilateral and severe ptosis as well as other abnormalities such as constricted lids, increased distance between the medial canthi, absent epicanthal folds, flat nasal bridge and low set ears. (5) 2007 227 answer D 28 weeks regardless ROP is the leading neonatal cause of blindness in the US. Up to 400 infants each year are blinded by this condition. It affects 20-50% of all NICU patients weighing less than 1500g with particular predilection for the smallest and most immature newborns. Blindness is greatly increased in infants who have stage 3 or 4 disease. The theories of contributing causal factors include extreme prematurity, very low birth weight, exposure to supplemental environmental oxygen, possible oxidizing agents exposure including iron and the generation of inflammatory cytokines. Perturbation of programmed angiogenesis in the developing retina ex utero and corresponding metabolic changes result in certain vascularized and ischemic zones of the retina. Vascular endothelial growth factor is altered and a proliferative vasculopathy that has immature, leaky and tortuous tufts of new vessels jeopardizes perfusion of the retina and imparts biomechanical traction upon it. Results of these processes include impaired peripheral vision in the peripheral zones of vascularity and potential retinal detachment with corresponding blindness or visual field deficits. The greatest risk for ROP is in infants born at less than 29 weeks gestation who weight less than 1200g. Because retinal vascularity generally is completed by 37-44 weeks gestation, prematurity itself confers risk, but the risk is shifted toward the extreme end of prematurity. Oxygen therapy is a contributing risk factor, but imposes the greatest risk in the smallest and most immature infants. Myopia is more common in the VLBQ preterm infants than in term infants but a family history of myopia has no bearing on the risk of ROP. In view of these facts and findings about ROP, the AAP, the American academy of ophthalmology and the American association for pediatric ophthalmology and strabismus jointly published guidelines for ROP screening examination of preterm infants. Candidates for screening include infants whose birthweights are less than 1500g, whose gestational ages are less than 32 weeks, and selected infants 1500-2000g at birth who have an unstable clinical course if judged to be at risk by the attending pediatrician or neonatologist. The examination should be performed by a qualified and experienced ophthalmologist and the results using the international classification of ROP. The first examination should be performed between 4 and 6 weeks of postnatal age or at a corresponding postconceptual age of 31-34 weeks whichever is later. (6) Question 2007 144 answer A blow out fracture The findings described for the boy in the vignette are indicative of an internal orbital or blow out fracture, which is defined as a fracture of the orbital floor or the orbital wall with an intact orbital rim. This is an uncommon injury before 8 years of age, possibly due to poorly pneumatized sinuses in very young children. Rupture of the orbital wall often is accompanied by extrusion of orbital soft tissue, including periosteum, fat, or muscle. Entrapment of the inferior rectus muscle and less commonly, the medial rectus muscle is manifested by impaired eye movements. Impaired eye movements results in intermittent diplopia, depending on the direction of eye movement. Surgical reduction is required within 4-10 days to prevent necrosis and subsequent fibrosis of the entrapped tissue. A child who has suspected blow out fracture should be evaluated by oribital CT scan. Skull films are of limited value. CT scan is especially valuable because it allows for evaluation of both the bony orbit and the globe. Associated injuries include ruptured globe, retrobulbar hemorrhage, and traumatic optic neuropathy, the first two of which can be demonstrated on CT scan. A child in whom a blow out fracture is confirmed should be examined immediately by an ophthalmologist to determine the need for surgical reduction, assess for associated for injuries and monitor for complications. Corneal abrasion, detached retina, hyphema, and traumatic iritis can occur in children in association with a blow out fracture. Corneal abrasion causes severe pain and tearing but doesn’t cause dysconjugate gaze or diplopia. Hyphema refers to blood in the anterior chamber, which may cause visual impairment but generally not diplopia. Traumatic iritis is characterized by pain and severe photophobia but no diplopia. Detached retina can cause a curtainlike deficit in the peripheral vision but doesn’t cause dysconjugate gaze. A detached retina is an ophtho emergency! (7) 2007 128- answer B A red eye in a patient who wears contact lenses may represent dangerous corneal infections due to gram negative bacteria or fungi or to breakdown and ulceration of the corneal epithelium. Such patients should have their contacts removed and be evaluated by ophtho within 12 hours. Empiric antibiotics are not recommended; antibiotic therapy should be directed ny the ophthalmologist, depending on the problem identified. For those who do not wear contacts and who have either corneal abrasion or bacterial conjunctivitis, empiric therapy with a topical antibiotic is appropriate. Common causes for a red eye in contact lens wearers include microbial keratitis, contact lens induced acute red eye (CLARE), and contact lens induced peripheral ulcer (CLPU). Microbial keratitis is an infection of the cornea characterized by excavation and necrosis of tissue. Inappropriate treatment or a significant delay in treatment can result in visual impairment. Removal of contact lenses and frequent instillation of sterile saline drops generally result in complete recovery from CLARE and CLPU. Fluorescein stain is taken up by damaged ocular epithelial cells. In a corneal abrasion, fluorescein uptake is focal at the site of injury. With microbial keratitis and CLARE, the uptake is both multifocal and diffuse. Prescribing opthalmic antihistamine drops and asking the patient to return for re- examination in 2-3 days are unnecessary delays to further evaluation and treatment by ophtho. (8) 2006 246 answer D Oral antihistamine The combination of eye pruritis, watery discharge, and nasal congestion reported for the boy in the vignette suggests allergic conjunctivitis. Allergic conjunctivitis is characterized by tearing, conjunctival edema (chemosis) and eyelid edema. Intense pruritis is typical, which helps the clinical distinguish allergic conjunctivitis from infectious causes, which usually do not cause significant itching. Allergic rhinitis is a common association, but other signs of atopy such as eczema or asthma may be seen as well. Eye involvement typically is bilateral and seasonal recurrence may be elicited on history. Oral antihistamines can decrease the symptoms of both the conjunctivitis and rhinitis. Other treatment options include cool compresses and topical cromolyn sodium. Because allergic conjunctivitis is not contagious, isolation is not required. Viral conjunctivitis is characterized by bilateral mucoserous discharge and conjunctival injection. Adenovirus is the most common cause. Bacterial conjunctivitis is associated with mucopurulent eye discharge and conjunctival papillae and patients may report a foreign body sensation. Bacterial conjunctivitis should be treated with topical antibiotic drops unless otitis media is also present. A foreign body in the eye causes tearing, pain, and conjunctival erythema unilaterally. Fluorescein staining often reveals a corneal abrasion and irrigation with normal saline can help flush out the foreign body. (9) 2006 9 answer C JRA The more common causes of red eye are conjunctivitis, which can be viral, bacterial, or allergic, trauma, such as corneal abrasion; blepharitis; and uveitis. Patients who have infectious conjunctivitis usually have preceding history of URI along with red or pink eye, mucous discharge, and matting of the eyelids. Infectious conjunctivitis typically is self limited process that improves in 1-2 weeks. Children who have corneal abrasion complain of a painful red eye, fluorescein dye typically reveals a corneal defect. Blepharitis presents with inflammation of the eyelid margins, usually caused by staph. The patient described in the vignette has a red eye that has not responded to two courses of the antibiotic ophthalmic drops and has negative results on fluorescein examination. She ultimately is diagnosed with uveitis, a nonspecific term used to describe any inflammatory condition of the uveal tract that is composed of the iris, ciliary body, and choroid. Iritis and iridocyclitis describe inflammation of the iris and iris-ciliary body complex of the anterior segment of the eye (anterior uveitis). In the posterior segment of the eye, chorioretinitis, retinitis, and vitreitis refer to inflammation of the choriod or retina and the vitreous (posterior uveitis). Children who develop anterior uveitis often complain of redness, pain, and photophobia. The onset of symptoms may be acute or insidious and the disorder can be unilateral or bilateral. The diagnosis is usually made by a slit lamp exam by ophtho. Although the cause of uveitis often is unknown, a variety of disorders are associated with the condition, including autoimmune diseases, such as Behcet disease and sarcoidosis. The most common disorder associated with anterior uveitis in children is the pauciarticular form of JRA. Toxo is the most common cause of POSTERIOR uveitis. Crohn disease, HSV and sarcoidosis are less common causes of anterior uveitis in children. (10) question 24 from 2006 answer E warm compress The boy described in the vignette has a stye (hordeolum) an infection usually staph that involves the glad of Zeis at the base of the follicles of the eyelashes along the lid margin. It is characterized by erythema and swelling of the eyelid that often is asymptomatic, although some children complain of mild discomfort or pain. An erythematous nodule on the skin surface of the eyelid is an external stye. An internal stye is a red nodule on the conjunctival surface. In children, most styes resolve rapidly with warm compresses applied to the eye several times a day for 15-20 min. Observation without treatment is inappropriate and may lead to worsening infection. Topical antibiotics can be used, but they are not necessary for resolution of the condition. Ophthalmic topical steroids are used most frequently to suppress immune mediated eye disorders. They should be used with caution because they can cause cataracts and glaucoma and can worsen HSV conjunctivitis. Because of these complications, consultation with ophtho is recommended before prescribing them. Oral antibiotics and i&d are not recommended for the treatment of stye. Chalazions are included in the differential diagnosis of the eyelid nodule. Unlike a stye which occurs acutely, chalazion are chronic granulomatous infalmmations of the meibomaian gland. They are typically painless and slow growing. most resolve spontaneously within several weeks. Warm compresses and antibiotics are not effective in treating chalazions. If they do not resolve spontaneously after several months they should be removed surgically by an ophthalmologist. (11) question 41 from 2006 answer C intraocular pressures Clinicians who care for children need to know the signs and symptoms of glaucoma because delay in making diagnosis may lead to permanent visual loss. Congenital or infantile glaucoma is relatively uncommon occuring in 1:10,000 births. Glaucoma can be present at birth, but is more commonly seen within the first 6 postnatal months. This disorder occurs more commonly in males. Infants who have glaucoma may experience tearing in the affected eye which may suggest nasolacrimal duct obstruction. However, this infant also has photophobia, one of the hallmarks of glaucoma. Parents of infants who have glaucoma may note that bright lights seem to bother the infant. On PE affected infants may have corneal edema, which makes the cornea appear hazy or cloudy. The affected eye enlarges in response to the increased ocular pressure. This corneal edema may cause an irregular corneal light reflex or dull the red reflex. Children who exhibit these findings should be referred immediately to ophtho for measurement of intraocular pressure to confirm diagnosis. Most cases of congenital glaucoma are sporadic but in some cases the disease is inherited. The inheritance pattern may be AD or AR and with variable penetrance. A variety diseases of the eye (ROP, aniridia) systemic diseases, and trauma can cause secondary glacoma in infants and children. Other systemic disease that are associated with glaucoma include metabolic disorders (homocystinuria) genetic disorders (marfan, down) neurocutaneous disorders (sturge-weber, NF) and infectious diseases (congenital rubella, HSV). Glaucoma also can be caused by prolonged ophtho or systemic steroid treatment. Ophtho steroids should be used with caution because of this complication. Children who are receiving long term oral steroids for systemic diseases should have IOP measured periodically. CT of head may be indicated in children who have glaucoma and neurocutaneous disorders after the IOP has been obtained. The prognosis for vision for infants who have glaucoma depends on normalization of IOP and prevention of optic nerve damage. Even after IOP is normalized, visual acuity and amblyopia require correction. In some children there may be other complications such as abnormalities of the optic nerve, cataracts, corneal opacities and retinal disease. 12) question 153 from 2006 answer D Leukocoria is seen as a white pupil when the eye is viewed with an ophthalmoscope, penlight, or room light. Children who have leukoria have an abnormal red reflex. A number of different conditions are associated with leukocoria, including neoplastic conditions (retinoblastoma) , retinal abnormalities (ROP), developmental abnormalities (chorioretinal coloboma), inflammatory conditions (toxocariasis) and other conditions such as cataracts. Cataracts are a major cause of leukocoria. Approximately 25% of the cases are familial, one third related to maternal infection, one third are idiopathic sporadic cases and the remainder are related to particular syndromes and systemic diseases some of which are hereditary. Maternal infections that cross the placenta such as toxo and rubella, cmv, HSV, HIV and varicella often cause characteristic eye conditions. Of these congenital rubella infection is associated most commonly with congenital cataracts. Maternal rubella infection causes congenital rubella infection in as many as 85% of neonates if it occurs in the first 4 weeks of gestation; the occurance rate is only 5% if rubella occurs in the third or 4th month of gestation. Common findings in infants who have congenital rubella include eye abnormalities such as cataracts, glaucoma, retinopathy as well as sensorineural hearing loss, heart disease (peripheral branch pulm artery stenosis, PDA) and MR. Affected infants often have IUGR, HSM, thrombocytopenia, and purpuric skin lesions (blueberry muffin rash) Aprrox 1/3 of neonates who are born with HSV have skin, eye, and mouth disease. COnjuntivitis and keratitis can result from infections but cataracts are rare. CMV infections and toxo can cause hearing impairment but they do not usually cause cataracts. Chorioretinitis is seen more commonly with these infections. Infants born with HIV are at risk for opportunistic infections such as CMV, varicella, and HSV as a result, they can develop CMV chorioretinitis and herpes ocular lesions.
Pages to are hidden for
"Board Review The Eye week of"Please download to view full document