Docstoc

Board Review The Eye week of

Document Sample
Board Review The Eye week of Powered By Docstoc
					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.