Chapter 18 - Ophtho Flashcards
1
Q
What are the four parts of vision screening?
A
I-ARM
- inspection
- acuity assessment
- red reflex testing
- motility assessment
2
Q
Describe visual acuity at birth and how it changes during infancy.
A
visual acuity is very poor at birth (~20/200) because of immaturity of the visual centers in the brain, but it improves rapidly during the first 3-4 months of life as a clear, in-focus retinal image stimulates functional and structural development of the visual centers of the brain
3
Q
List six disorders that would present as an abnormal red reflex.
A
- cataract
- vitreous hemorrhage
- retinoblastoma
- anisometropia
- strabismus
- glaucoma
4
Q
Normal visual development in the early months of life is dependent on what two things?
A
proper eye alignment and equal visual stimulation of each retina with clearly focused images
5
Q
When is visual development most critical?
A
during the first 3-4 months of life
6
Q
Define amblyopia.
A
poor vision caused by abnormal visual stimulation that results in abnormal visual development; remember that proper development of acuity in the first 3-4 months of life requires proper eye alignment and equal visual stimulation of each retina with focused images
7
Q
Amblyopia
A
- poor vision caused by abnormal visual stimulation that results in abnormal visual development
- it is the most common cause of decreased vision during childhood
- may be caused by eye misalignment (strabismus) or a condition that causes blurred vision (e.g. cataract, severe uncorrected refractive error, significant differences in refractive errors between the eye, or virtuous opacities)
- the severity of the condition depends on when the abnormal stimulus began, length of exposure, and severity of the blurring
- the red reflex test is the best screening test in preverbal children and formal acuity testing is best in older children
- manage by correcting any refractive errors or by surgical removal of cataracts and patching the normal eye to force use of the amblyopic eye which stimulates development
8
Q
How is amblyopia managed?
A
- treatment of the underlying cause
- patching of the normal eye, which forces reliance on and development of the amblyopic eye
9
Q
Contrast gonococcal and chlamydial neonatal conjunctivitis.
A
- gonococcal has an onset between 2-4 days of life with more severe eyelid swelling, profuse purulent discharge, and eventual corneal ulceration; it should be treated with a single IM dose of cefotaxime and topical erythromycin
- chlamydial as an onset of 4-10 days with mild eyelid swelling and a more watery, seroanguineous, or mucopurulent eye discharge; treatment is with PO erythromycin
10
Q
HSV Neonatal Conjunctivitis
A
- presents 6-14 days after birth, typically with unilateral serous discharge
- find multinucleate giant cells on gram stain and culture is positive for HSV
- treated with IV acyclovir and topical trifluorothymidine
11
Q
Chemical Neonatal Conjunctivitis
A
- caused by drops or ointment, particularly 1% silver nitrate, which is why we use the less irritating 0.5% erythromycin now
- presents in the first 24 hours of life with a water discharge and resolves within 24 hours without treatment
- conjunctival studies demonstrate a negative gram stain and few PMNs
12
Q
What is blepharitis?
A
eyelide inflammation
13
Q
Unilateral conjunctivitis in an older child suggests what?
A
- foreign body
- corneal ulcer
- herpes simplex keratitis
14
Q
Conjunctivitis associated with contact lens use in older children is suggestive of what?
A
- allergy to the contact solution
- corneal abrasion
- vision-threatening bacterial corneal ulcer
15
Q
Bacterial Conjunctivitis
A
- most often caused by non-tapeable H. influenzae, Strep pneumonia, Moraxella catarrhalis, or S. aureus
- presents with a purulent discharge, conjunctival erythema, and lid swelling bilaterally
- there is typically no lymphadenopathy
- culture and gram stain are rarely performed unless the case is severe and treatment is empiric
- treatment is with topical antibiotics including sulfacetamide, polymyxin B, trimethoprim sulfate, gentamicin, tobramycin, and erythromycin
16
Q
What are the distinguishing features of viral conjunctivitis?
A
presents with minimal watery discharge, preauricular lymphadenopathy, and a negative gram stain
17
Q
Pharyngoconjunctival Fever
A
- caused by adenovirus
- it is a URI that includes pharyngitis, fever, and bilateral conjunctivitis characterized by severe watery discharge, chemises, lymphadenopathy, and a foreign body sensation caused by corneal involvement
- it is highly contagious
- treated with cool compress and topical NSAIDs
18
Q
Epidemic Keratoconjunctivitis
A
- caused by adenovirus
- it presents with petechial conjunctival hemorrhage, preauricular lymphadenopathy, a pseudomembrane along the conjunctiva, photophobia from corneal inflammation
- lacks fever or pharyngitis
- highly contagious
- treatment is supportive
19
Q
Primary Ocular Herpes Simplex Virus
A
- caused by HSV-1 and often representing the initial exposure to the virus
- presents with multiple vesicular lesions and may cause a corneal ulcer
- diagnosed based on positive viral culture or DFA of vesicular fluid
- treated with systemic or topical acyclovir and topical antibiotics to prevent secondary bacterial infection
20
Q
Allergic Conjunctivitis
A
- a type I hypersensitivity reaction
- characterized by marked, bilateral itching and watery or mucoid discharge; there is no lymphadenopathy
- eosinophils can be found on conjunctival scraping
- treated with removal of allergens, topical mast cell stabilizers, and topical antihistamines
21
Q
Hemorrhagic Conjunctivitis
A
- caused by H. influenzae, adenovirus, or picornavirus
- presents with conjunctivitis and subconjunctival hemorrhage
22
Q
Blepharitis
A
- eyelide inflammation usually caused by S. aureus
- presents with burning, crusting, and scales at the eyelash base; broken or absent eyelashes; and a history of awakening in the morning with eyelashes stuck together
- treat with eyelid hygiene and topical erythromycin
23
Q
Nasolacrimal Duct Obstruction
A
- a failure of complete canalization of the lacrimal system resulting in obstruction to tear outflow, most often distally at Hasner’s valve
- presents with a watery eye and increased tear lake, matted eyelashes, and mucus in the medial canthum; it is often bilateral
- half of cases resolve spontaneously within 6 months while the other half require NLD probing; until then, nasolacrimal massage and topical antibiotics are the preferred treatment
24
Q
Amniotocele
A
- a swelling of the nasolacrimal sac
- caused by accumulation of fluid as a result of NLD obstruction
- presents with bluish swelling in the medial cantonal area, which represents fluid sequestered in the nasolacrimal sac, and infection may occur with warmth, erythema, and tenderness
- treat with local massage and IV antibiotics plus urgent NLD probing if infection is present
25
Retinal Hemorrhage
- highly suggestive of child abuse
- but can be caused by birth trauma, leukemia, increased ICP, malignant hypertension, etc.
- presents as hemorrhagic dots and blots found no fundoscopic exam
26
Corneal Abrasion
- damage to and loss of corneal epithelium
- caused by trauma, including from contact lens use
- presents with severe pain, tearing, photophobia, and foreign body sensation
- diagnosed with fluorescein staining
- typically heals on its own within 1-2 days; you may considered placement of a patch in severe cases or application of topical antibiotics to prevent superinfection
27
Hyphema
- blood within the anterior chamber
- most often caused by blunt trauma, which compresses the globe; when the globe re-expands, the iris vasculature tears
- may also be caused by iris neovascularization as in diabetes, intraocular tumors, or retinal vascular disease
- a blood-aqueous fluid level may be seen, and a large hyphen may obscure the pupil, thus impairing vision
- may be complicated by rebreeding, glaucoma, staining of the cornea, or optic nerve damage
- treated with bed rest for at least 5 days
28
Orbital Floor Fracture
- common following blunt trauma to the eye or orbital rim given that the bone is thin
- orbital fat or the inferior rectus muscle may become entrapped within the fracture, leading to diplopia, strabismus, and enophthalmos
- there may be numbness of the cheek and upper teeth if there is concordant infraorbital nerve injury
- should be treated with oral antibiotics to prevent infection with organisms from the maxillary sinus; surgical repair is indicated if diplopia persists for 2-4 weeks
29
Congenital Glaucoma
- increased intraocular pressure exceeding 30 mmHg (normal is 10-15 mmHg)
- differs from adult glaucoma in that there is not only optic nerve injury but also an expansion of the size of the eye because the eye wall is more elastic in infancy
- there is associated corneal edema, corneal clouding, and amblyopia
- may be due to maldevelopment of the trabecular meshwork, which reduces outflow; some cases are autosomal dominant; others are due to infection, aniridia, or genetic syndromes
- presents with tearing, photophobia, enlarged cornea, corneal clouding, and a dull red reflex (don't confuse with NLD obstruction because of the tearing)
- typically requires surgery to open outflow channels; beta-adrenergic agonists and carbonic anhydrase inhibitors may help
30
Retinopathy of Prematurity
- a proliferation of vessels seen in premature infants exposed to high concentrations of oxygen
- risk factors include birth weight less than 1500g, gestational age less than 28 weeks, blood transfusions, hyaline membrane disease, and intracranial hemorrhage
- may be complicated by myopia, astigmatism, amblyopia, strabismus, and blindness
- prevention rests on minimizing the use of supplemental oxygen and effectively treating hyaline membrane disease
- infants with risk of ROP receive dilated examination at 4-6 weeks of age and those found to have ROP have examinations every 1-2 weeks to monitor for progression
- if disease is severe, it may require retinal cryotherapy or laster therapy
31
What is leukocoria?
- it is a white pupil, which typically refers to an opacity at or behind the pupil
- may be caused by a cataract, opacity within the vitreous, or by retinal disease such as retinoblastoma
32
Congenital Cataract
- an opacity of the lens present at birth
- most are idiopathic but they may be a feature of Down, Marfan, or Alport syndrome; galactosemia; intrauterine infections with CMV or rubella; and trauma
- early surgery is required to prevent amblyopia
- the prognosis is good if the surgery is performed in the first two months of life
33
Retinoblastoma
- a malignant tumor of the sensory retina
- due to a mutation or deletion of both alleles of a tumor suppressor gene on chromosome 13, which may be sporadic or inherited in an autosomal recessive fashion
- typically presents between 13-18 months of life with leukocoria and strabismus
- imaging likely demonstrates calcification within the tumor
- large tumors have a poor prognosis and require surgical removal of the whole eye
34
Strabismus
- a misalignment of the eyes
- may be classified as esotropia, exotropia, vertical strabismus, or pseudostrabismus
- presentation depends on age: before 5-7 years of age, the child will suppress the image in the deviated eye, leading to amblyopia; after 5-7 years of age the mature visual system can't suppress the image and diplopia is the result
- treated with ocular patching to prevent amblyopia, corrective lenses if necessary, and surgery if refractory
35
Define esotropia, exotropia, and pseudostrabismus.
- esotropia: the eye is turned medially
- exotropia: the eye is turned temporally
- pseudo strabismus: the epicentral folds have a prominence that gives rise to the false appearance of strabismus when the eyes are actually aligned
