B20M02L05Childhood Eye Diseases

8/16/2019 B20M02L05Childhood Eye Diseases

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Illiterate “E” Chart or HOTVmatching optotypes and SnellenChart

o Stereoacuity Test (3D Vision orStereognosis)

Development of Visual Acuity (Approximate):

Age Visual Acuity

2 months 20/4006 months 20/100z

1 year 20/50

3 years 20/20

REFRACTION important part of the exam performed under Cyclopedia

o children under 10 years old o pediatric eyes have a high degree of

accommodation, doctors have a tendency tounderestimate refraction due to theiraccommodative power

o paralyze ciliary muscles to paralyzeaccommodation in order to determine theReal Refraction; 1% cyclopentolate drugsand Atropine

80% between 2-6 ages are hyperopic o Normal, as long as grade is not too high o At 2 y/o, 300 is still normal. If 700, give

glasses o Normal ranges of hyperoppia for each age

group

o For a 1 y.o, if the hyperopia is 4 or 5,observe, no need for glasses. But for a 5 y.o,if the hyperopia is 4 or 5, it’s already

potentially amblyogenic. We give glasses. 5% are myopic; and 15% are emmetropic 10% has refractive errors that need correction

before age 7 or 8 – give glasses o If a 1 y.o. is myopic by 150, no need for

glasses yet. His words are still near, he’d just play with toys and would just look at his parents. No need for good vision at this age.But if grade is 900, it is too high. It is

potentially amblyogenic and we giveglasses.

CONGENITAL OCULAR ABNORMALITIES Main Categories:

Developmental anomalies- genetic defects Tissue reactions to intrauterine cause-infections,

drugs

CONGENITAL ABNORMALITIES OF GLOBE

Anophthalmos - Failure of formation of the opticvesicle

Congenital cystic eye - Failure of invaginationColobomas of the iris, retina, and/or choroid -Failure of optic vesicle/fissure closure

Cryptophthalmos – failure of eyelids to separate Small eyes:

o Nanophthalmos - function is normalo Microphthalmos - function is abnormal and

there may be other ocular abnormalitiessuch as cataract, coloboma, or congenitalcyst

CONGENITAL PTOSIS

Due to dystrophy of levator muscle – moveeyelidsupward; common,

o Levator muscle- muscle that elevate uppereyelid, treatment is surgery

o isolated dystrophy of the levator muscleaffecting both contraction and relaxation ofthe fibers

o present in the primary position of gaze, andthere is reduced movement of the lid inupgaze and impaired closure on downgaze

o Lid lag on downgaze - important clue todiagnosis

Due to Congenital Horner’s Syndrome orCongenital 3 rd Nerve Palsy

o inappropriate movements of the globe,eyelid, and pupil which may lead toamblyopia

o Characteristic drooping eyelids Treatment: Surgical

o Mild – Moderate: Levator Resection open eyelids, cut one part, shorten it

and reappose o Severe: Frontalis Sling

harvest fascia lata ( ideally: fromthigh ) or synthetic sling, suture underthe eyelid and the other is in the

frontalis muscle Drawback: patient is sometimes

unable to close their eyes when theysleep. They must use lubrication, ifnot exposure keratitis may occur,especially in Bell’s Phenomenon. It isthe phenomenon of the ball movingup when you forcibly open theeyelids. If yo u don’t use lubrication, itis very painful.


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Ideal time of surgery: 3 to 4months after birth to preventamblyopia.

aphakic optical correctionimmediately

give glasses or contact lens at1 y/o

Unilateral- contact lens;Bilateral- glasses

amblyopia treatment

Developmental Variants. Discrete dots or whiteplaquelike opacities of the lens capsule are common andsometimes involve the contiguous subscapular region.Trauma to the eye is a major cause of cataracts inchildren. Opacification of the lens may resultfromcontusion or penetrating injury. Cataracts are animportant manifestation of child abuse.

Metabolic Disorders• classic galactosemia, galactose-1-phosphate uridyltransferase deficiency, the cataract is typically of thezonular type, with haziness or opacification of 1 or moreof the perinuclear layers of the lens Haziness or cloudingof the nucleus also often occurs

• Hypoglycemia in neonates can also be associated withearly development of cataracts. Ketotic hypoglycemia isalso associated with cataracts• oculocerebral renal syndrome of Lowe is associatedwith cataracts in infants. Affected male childrenfrequently have dense bilateral cataracts at birth, oftenin association with glaucoma and miotic pupils.

SUBLUXATION in Marfan’s Syndrome

COLOBOMA faulty development of lens

OPTIC NERVE HYPOPLASIA non progressive unilateral/bilateral small optic disc double ring sign – circumpapillary halo of the

normal sized scleral canalo optic nerve is smaller than scleral canal o optic cup pale compared to the rim

Coloboma of the iris is a developmental defectthat can occur as a hole in the substance of theiris, or a notch in the pupil’s margin

often transmitted as an autosomal dominant traitand can occur alone or in association with otheranomalies

formed when the embryonic fissure fails toclose completely. Because of the anatomiclocation of the embryonic fissure, an iriscoloboma is always located inferiorly, givingthe iris a keyhole appearance.

Ectopia lentis occurs in approximately 80% ofpatients with Marfan syndrome, and in about50% of patients;

the ectopia is evident by the age of 5 yr. In mostcases, the lens is displaced superiorly andtemporally; it is almost always bilateral andrelatively symmetric

Abnormalities of the suspensory system resulting

from a developmental defect, disease, or traumamay result in instability or displacement of thelens. Displacement of the lens is classified asluxation (dislocation –complete displacement ofthe lens) or as subluxation (partial displacement –shifting or tilting of the lens)

Developmental VariantsEarly developmental processes may lead tovarious congenital lens opacities.

Discrete dots or white plaquelike opacities of thelens capsule are common and sometimes involvethe contiguous subcapsular region

Mittendorf dot - Small opacities of the posteriorcapsule may be associated with persistentremnants of the primitive hyaloid vascular system

Congenital cataracts of this type are usuallystationary and rarely interfere with vision

Prematurity

A special type of lens change seen in somepreterm newborn infants is the so-called cataractof prematurity.

The appearance is of a cluster of tiny vacuoles inthe distribution of the Y sutures of the lens.

In most cases, the opacities disappearspontaneously, often within a few weeks.

Mendelian Inheritance

The most common mode of inheritance isautosomal dominant.

Penetrance and expressivity vary

Autosomal recessive inheritance occurs lessfrequently; it is sometimes found in populationswith high rates of consanguinity.

X-linked inheritance of cataracts unassociatedwith disease is relatively rare.


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o Double Ring Sign Frequent associated midline deformities – defects

in brain o absence of septum pellucidumo agenesis of corpus callosum o dysplasia of

3rd ventricleo pituitary or hypothalamic dysfunction-

most important to watch out for. NeedsEndocrine referral

Neuroradiologic investigations – CT Scan,MRI

Hypoplasia of the optic nerve is anonprogressivecondition characterized by a subnormalnumber of optic nerve axons with normal mesodermalelements and glial supporting tissue. In typical cases, thenerve head is small and pale, with a pale or pigmentedperipapillary halo. This anomaly is associated withdefects of vision and of visual fields of varying severityranging from blindness to normal or near-normal vision.

CONGENITAL NASOLACRIMAL DUCT OBSTRUCTION 30% of babies have epiphora at 1 st month of life

o Canalization of the distal nasolacrimal ductnormally occurs before birth or during 1 st month of life

Most cases resolve by 1 year of ageo Punctal massage

o Nasolacrimal probing- done for those persistentepiphora after 1 year of age; guided wirethrough

nasolacrimal duct and pierce the distal part ofcanal thereby creating an opening for the tears toget through

o Success rate of surgery at: 1 yr-90% 2 yr-70% 3 yr-50% Beyond 3 yrs- lower; still do probing. If not

effective do dacrocystorhinostomy

o

Nasolacrimal Probing

POSTNATAL EYE PROBLEMS o Most common are:

external infections of conjunctiva & eyelids Amblyopia strabismus

ocular foreign bodiesallergic reactions of conjunctiva & eyelidsrefractive errors

OPHTHALMIA NEONATORUM 1. Chemical

It is the most common disorder of the lacrimalsystem

It is usually caused by a failure of canalization of theepithelial cells that form the nasolacrimal duct as itenters the nose (valve of Hasner).

Signs of CNLDO may be present at the time of birth,although the condition may not become evident untilnormal tear production develops.

Signs of CNLDO include an excessive tear lake, overflowof tears onto the lid and cheek, and reflux of mucoidmaterial that is produced in the lacrimal sac.

Erythema or maceration of the skin may result fromirritation and rubbing produced by dripping of tears anddischarge

may develop acute infection and inflammation of thenasolacrimal sac (dacryocystitis),inflammation of thesurrounding tissues (pericystitis),or rarely periorbitalcellulitis.

With dacryocystitis, the sac area is swollen, red, andtender, and patients may have systemic signs of infectionsuch as fever and irritability.

Optic nerve hypoplasia is a principal feature ofsepto-optic dysplasia of de Morsier a developmental disorder characterized by the association of anomalies of the midline

structures of the brain with hypoplasia of the opticnerves, optic chiasm, and optic tracts

typically noted are agenesis of the septumpellucidum, partial or complete agenesis of thecorpus callosum, and malformation of the fornix,with a large chiasmatic cistern.

panhypopituitarism to isolated deficiency of growthhormone, hypothyroidism, or diabetes insipidus.Neonatal hypoglycemia and seizures are importantpresenting signs in affected infants


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o Caused by silver nitrate drops – instilledinconjunctival sac at birth for prophylaxis;not used anymore

o Will cause a secondary chemicalconjunctivitis

o most apparent during 1 st and 2 nd day of lifeo self-limitedo some advocate as the topical erythromycin

and tetracycline2. Chlamydial Infection

o most common identifiable infectious causeo Onset bet. 5 th and 14 th day of lifeo Giemsa stain : typical inclusion bodies in

theepithelial cells of conjunctival scrapingsandobserve under microscope – confirmsdiagnosis

o systemic therapy + topical erythromycino parents should be treated since it is an STD

3. Bacterial Infectiono caused by:

Staphylococcus aureus

Hemophilus sp. Streptococcus pneumonia Neiserria gonorrhea Pseudomonas sp.

o Presents between 2 nd and 5 th day of lifeo Gonococcal conjunctivitis requires

parenteral therapy IM Ceftriaxone Pen G ( IV for penicillin-

sensitivestrains) Parents should be treated

o Topical therapy Sodium sulfacetamide, Bacitracin,

Tetracycline4. Viral Infection

o Herpes Simplex Characteristic giant cells and viral

inclusions on cytologic examination Resolve spontaneously May need antivirals – severe cases

RETINOPATHY OF PREMATURITY Retrolental fibroplasias

o fibrous membrane at the back of lens; rare o stage 5 ROP – total retinal detachment o incomplete retinal revascularization

Retinal revascularization proceeds centrifugallyfrom optic nerve

o ophthalmic artery and vein->optic nerve->spreads in periphery of retina

Retinal vessel reaches the nasal ora serrata at 8months and the temporal ora serrata at 9 months.

o Complete revascularization at 9 moso Born at 7 months: lack of blood vessels in

peripheral retina Usually bilateral but asymmetric

ROP develops when the processes were disturbed.

International Classification of Acute ROP Stages

Location: o Zone II and III are based on convection

rather than strict anatomyo Zone I (posterior pole): circle with radius of

30 deg., twice disc-macula distance; directophthalmoscopy

o Zone II: from edge of zone I to pointtangential to nasal ora serratia and aroundto the area near the temporal equator.

o Zone III: Residual crescent anterior to ZoneII (at the temporal side)

Extent o Specified as hours of the clock as the

observer looks at each eye. Staging (using Indirect Ophthalmoscopy):

o I- Demarcation line thin yellowish line separating

vascular area from avascular area ofretina, flat line, no volume

o II- Ridges, +/- small tufts or thefibrovascular proliferation

o III- Ridge w/ extraretinal fibrovascularproliferation,

formation of new blood vessels ontop of the ridge, it spreads in thesubstance of vitreous, contraction ofwhich causes retinal detachment.

In an area of retinal ischemia, it willsecrete VEGF that will stimulategrowth of new blood vessels. Butthese new BV would grow into the

vitreous cavity. When it regresses, itcontracts, forming membranes thatwill pull the retina, causing tractionalretinal detachment

o IV-Subtotal retinal detachment A- does not incude macula B- includes macula or fovea

o V- Total retinal detachmentTortuosity

o Dilatation of blood vesselso Too much vascular shuntingo Plus Disease


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o plus (+) is added when vascularshunting is so marked that theveins are enlarged and the arteriesare tortuous in the posterior pole;more severe

o Makes the prognosis worseMajor Risk Factors

Decreasing gestational age Decreasing birth weight

It’s not the absolute weight, but itsrelation to the gestational age.

28 weeks, 800 grams= sometimes theydon’t develop ROP

30 weeks, 1000 grams= develop ROP(should consider both weight andgestational age)

Supplemental oxygen – the higher the 02, thehigher chance of RoP.

Acidosis, apnea, patent ductus arteriosus,septicemia, blood transfusion, intraventricularhemorrhage.

Screening Recommendations Infants birth weight of less than 1500 grams or

AOG of 32 wks or less, as well as selected infantswith unstable clinical course, at least 2 fundusexams.

Should be performed by an ophthalmologist withsufficient regular experience and knowledge inthe examination of preterm infants

1st exam should normally be performed between4-6 weeks (after birth ) of chronological age oralternatively within the 31 st to 33 rd week of postconceptual or postmenstrual age (AOG) ,whichever is later .

E.g. if patient is 24 weeks old 24 + 4-6 weeks = 28-30 weeks – it

should be at least 31 weeks follow the 31 st-33 rd rule

Screening recommendation in the Philippines: pxborn at 35 weeks and below, 2000 grams andbelow = examine 2 weeks after birth

Aggressive Posterior Type ROP – progression in aweek

Treatment should generally be accomplishedwithin 72 hours of determination of threshold

ROP.o Threshold: stage 3+ ROP in 5 contiguous

clock hours or 8 cumulative clock hours ineither zone I or zone II.

Treatment of ROP Retinal photocoagulation (laser treatment) –

ablate (burn) the avascular area o Avascular area – it is the problem;

producesVEGF which produces abnormalblood vessels (neovascularization)

o Complication – limited peripheral vision Retinal cryotherapy – not done anymore Vitrectomy and lensectomy may be beneficial in

cicatricial disease – in stage 4 & 5 Anti-VEGF injections – also used in treatment

ofother ca like colon ca, slows down developmentof new blood vessels.

CONGENITAL GLAUCOMA Manifest at birth in 50%, diagnosed in the first 6months in 70%, and diagnosed by the end of thefirst year in 80%. The earliest and mostcommonsymptom is epiphora .

May be associated with other congenital lesions Often bilateral Signs and symptoms:

o Extreme photophobia - Infantsavoidopening their eyes and if they do, theywould suddenly close it because they feelextreme pain upon seeing bright lights

o Epiphora or Tearingo Corneal haze or opacity

Increased corneal diameter A later finding. Above 11.5mm is

considered significant.o Increased intraocular pressure (>10-20 mm

Hg) Is a cardinal sign

o Buphthalmus TREATMENT: Surgical – Immediate, may cause

blindness

The symptoms of infantile glaucoma include the classic

triad of epiphora, photophobia, and blepharospasm.Children with unilateral glaucoma generally present earlybecause the difference in the corneal size between theeyes can be noticed. When the disease is bilateral,parents might not recognize the increased corneal size,they view the large eyes attractive, thus late consult.Treatment. Procedures used to treat glaucoma inchildreninclude surgery to establish a more normalanterior chamber angle (goniotomy andtrabeculectomy), to create a site for aqueous fluid toexit the eye ( trabeculectomy and seton surgery ), or toreduce aqueous fluid production ( cyclocryotherapy andcyclophotocoagulation ).


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RETINOBLASTOMA

Rare malignant tumor of childhood Fatal if untreated

o Compatible with life as long as there are nooptic nerve and intracranial extensions.

90% of cases diagnosed before 3 years old.o Most of them are actually diagnosed before

age 1. 30% are bilateral

o If bilateral and multifocal – usually thehereditary type

o If unilateral with one mass inside the eye – usually secondary to mutation. Due to loss of normally protective dominant allele

at single locus within chromosome band 13q14. Common signs: leukocoria and strabismus Screen for children of families affected by

retinoblastomao The chance of an infant having

retinoblastoma if he has an older siblingwith retinoblastoma is increased comparedto those with no history.

Enucleation is the treatment of choiceo Used to be the treatment of choice before

when it has grown too big and has nochance to be salvaged

o In advanced countries: Globe salvage is thetreatment of choice

o Mean age of diagnosis in US: 15-18 months o Mean age of dx in Philippines: later than 2

years Other treatment modalities: Radiotherapy,

photocoagulation, cryotherapy.o With the advent of

chemoreduction,enucleation is less. Usuallyused nowadays for smaller masses. 3 cycles

of chemotherapy is given to decrease themass. Laser surgery is done afterwards to

photocoagulate the mass. o If mass is >1/2 of the globe, there is no

choice but to remove the eyeball. o If no recurrence at age 7, patient willmost

likely have normal life expectancy.

STRABISMUS

Any deviation from perfect ocular alignment:o Inwardo Outwardo Downo Up

4% of children Amount of deviation- angle by which the deviating

eye is misalignedo Treatment should be started as soon as a

diagnosis is made in order to ensure thebest possible visual acuity and binocularvisual function.

o There is no such thing as "outgrowing"childhood strabismus.

o Strabismus may also be acquired, caused bycranial nerve palsies, orbital masses, orbitalfractures, thyroid eye disease, or otheracquired disorders.

The median age at diagnosis is 2yr, and over 90% ofcases are diagnosed in children under 5

2/3 to ¾ of children with retinoblastoma haveunilateral tumors, with the remainder havingbilateral retinoblastoma.

The hereditary form is associated with loss offunction of the RB1gene located on chromosome13q14 and encodes the retinoblastoma protein (Rb)

tumor suppressor protein that controls cell-cyclephase transition and has roles in apoptosis and celldifferentiation.

Knudson’s “two -hit” model of oncogenesis - twomutational events are required for retinoblastomatumor development. In the hereditary form ofretinoblastoma, the first mutation in the RB1gene isinherited through germinal cells and a secondmutation occurs subsequently in somatic retinalcells.

Imaging studies are not diagnostic, and biopsies arecontraindicated. Indirect ophthalmoscopy with slit-lamp evaluation can detect retinoblastoma tumors

Occasionally, a pineal area tumor is detected in achild with hereditary retinoblastoma, aphenomenon known as trilateral retinoblastoma


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Muscles of the Eye and their Actions

Muscle PrimaryAction

Secondary Action

Lateral Rectus Abduction None

Medial Rectus Adduction None

SuperiorRectus

Elevator Add, Intorsion

Inferior Rectus Depressor Add, Extorsion

Superioroblique

Intorsion Depression, Abd

Inferioroblique

Extorsion Elevation,Abd

Intorsion and extorsion is the ability of the eye tomove within its axis. Say for example you tilt yourhead to the left, the left eye will intort and theright eye will extort. This allows us to still have astand still image even if our head is tilted.CN VI– supplies Lateral Rectus

CN IV– supplies Superior Rectus CN III– supplies the rest

Field of action- the direction of gaze in which themuscle exerts its greatest contraction force as anagonist

o Example: Lateral Rectus of the Right Eye When it tries to move right eye to the

right and out, it serves as its agonist.The movement of the right eye fromthe center to the right is the field ofaction of your right lateral rectusmuscle.

Sherington’s Law of Reciprocal Innervation(Agonist-Antagonist Law)

o Agonist is stimulated- the antagonistrelaxes

o Like when you like to look on the right withyour right eye. The Agonist muscle is yourright lateral rectus since it is the one thatcontracts in order to move your right eye tothe right, the right medial rectus musclenaturally relaxes in order to allow looking atthe right, therefore it is the antagonistmuscle.

o Synergistic and antagonistic muscles. Synergistic muscles are those thathave the same field of action. (E.g.For vertical gaze, the superior rectusand inferior oblique muscles aresynergists in moving the eyeupward.)

o The extraocular muscles, like skeletalmuscles, show reciprocal innervation ofantagonistic muscles. (E.g. In dextroversion(right gaze), the right medial and left lateral

rectus muscles are inhibited while the rightlateral and left medial rectus muscles arestimulated).

Hering’s law of motor correspondence (YokeMuscles)

o For movements of both eyes in the samedirection, the corresponding agonistmuscles receive equal innervations

o Yoke muscles are a pair of muscles, one ineach eye which act together to move botheyeballs toward one direction.

o Example: When you look to the right, yourright eye move to the right because of theright lateral rectus muscle, whereas yourleft eye will move towards the right becauseof the left medial rectus muscle. Thereforethese two muscles are yoke muscles whichallow both your eyeballs to move towardsthe right.

o The pair of agonist muscles with the sameprimary action is called a yoke pair. (e.g.

The right lateral rectus and the left medialrectus muscles are a yoke pair for rightgaze)

Yoke Muscles in Cardinal Positions of Gaze

Eyes up and right RSR and LIO

Up and left LSR and RIO

Right RLR and LMR

Left LLR and RMR

Down and right RIR and LSO

Down and left LIR and RSO R-right; L-left; SR-Superior Rectus; IO-InferiorOblique; LR-Lateral Rectus; MR-Medial Rectus; IR-Inferior Rectus; SO-Superior Oblique


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EXAMINATION History

o Family Strabismus and amblyopia are

frequently found to occur in familieso Age of onset

Important factor in long-termprognosis. The earlier the onset, theworse the prognosis of goodbinocular function

o Type of onset

Gradual, sudden, or intermittento Type of deviation The misalignment may be in any

direction. It may be greater in certainpositions of gaze, including theprimary position for distance ornear.

o Fixation One eye may constantly deviate, or

alternating fixation may beobserved.

Visual acuityo Most important part of your eye exam o Compare both eyes .

Determine Refractive Erroro By doing cycloplegic refraction.

Inspectiono Constant vs. intermittent o Alternating vs. non alternating

Alternating- deviation of right eye,sometimes left eye is deviated, much

preferred because it means the eye isnot amblyopic.

Non-alternating- the constantdeviated eye might be amblyopic.

Amblyopia-pros: no diplopia, cons: poor vision

o Variable (deviation is sometimes large,sometimes small) or constant (deviation isof the same amount every time youmeasure it).

o Other associated signs and symptoms like ptosis and abnormal head positioning

o There are cases wherin, ang patient nagastrabismic lang because of abnormal head

position, intorsion and extorsion are alsomovements of the eye, so kung mayhyperintorsion or hypoextorsion of themuscles, they will also present as strabismus

o Nystagmus (jerky movements of the eyes) o Prominent epicanthal folds

DETERMINATION OF ANGLE OF STRABISMUS Prism and Cover Tests

o Cover Test As the examiner observes one eye, acover is placed on the other to blockits view of the target.

If the observed eye moves to take upfixation, it was not previouslyfixating the target, and a manifestdeviation (strabismus) is present.

The direction of movement revealsthe direction of deviation (e.g., if theobserved eye moves outwardly topick up fixation, esotropia ispresent).

o Uncover Test As the cover is removed from the

eye following the cover test, the eyeemerging from under cover isobserved.

If the position of the uncovered eyechanges, interruption of binocularvision has allowed it to deviate, anda heterophoria is present.

The direction of correctivemovement shows the type ofheterophoria.

o Alternate Cover Test The cover is placed alternately infront of first one eye and then theother.

This test reveals the totaldeviation (heterotropia plusheterophoria if also present). Thecover should be moved rapidly fromone eye to the other to preventrefusion of a heterophoria.

Orthophoriais the ideal condition of exact ocularbalance. It implies that the oculomotor apparatus is inperfect equilibrium so that the eyes remaincoordinated and aligned.

Heterophoriais a latent tendency for the eyes todeviate. This latent deviation is normally controlled byfusional mechanisms that provide binocular vision or

avoid diplopia (double vision) Heterotropiais a misalignment of the eyes that isconstant. It occurs because of an inability of thefusional mechanism to control the deviation.

Tropias can be alternating, involving both eyes, orunilateral.

In an alternating tropia, there is no preference forfixation of either eye, and both eyes drift withequal frequency. Because each eye is used periodically,vision usually develops normally.

A unilateral tropia is a more serious situationbecause only one eye is constantly misaligned.


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o Prism Cover Test An increasing strength of prism is

placed in front of one eye until there

is neutralization of eye movementon alternate cover testing.

2. Hirschberg Reflexo Aim light and nasal bridge and observe

reflections of light at cornea. Normally,reflection should be at pupil center. If not atthe center, eye is deviated.

o The farther away from the center of the pupil, the bigger the strabismus is.

o 1 mm of deviat ion is equal to 7˚. Multiplythe degrees by 2 to get prism diopters. Byconvention, prism diopters is usually used to

describe the amount of deviation.

3. Prism Reflex Method (Reverse Krimsky Test)o Putting a certain amount of prism at the

deviated eye until the reflex falls at thecenter of the pupil. Prisms have

corresponding values. Start small andgradually increase until corneal reflection isat the center of the pupil.

o You will know the amount of deviationbased on the amount of prism diopters usedto neutralize the reflex.

TheKrimsky Test

4. Cover-Uncover Test (e.g. Esotropia)o to check alternating or non-alternating

strabismus o First, cover the unaffected eye (fixating

eye). o If the uncovered affected eye (deviating

eye) still has good vision, it will take up fixation and will move to the center.

o If it holds fixation after removal of the coveron the fixating eye, patient has an

ALTERNATING ESOTROPIA (both eyes can fixate alternately). Assume that vision isalmost the same in both eyes.

o If after removing the cover, the eye positions go back to their respective positions before the test, patient has someamount of AMBLYOPIA because the brain

prefers the unaffected eye (fixationg eye) intrying to fixate at an object.


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Cover-Uncover Test

Other Examinations 1. Ductions (Monocular Rotations)

o Checkfor extraocular movement by usingone eye at a time.

2. Versions- 9 diagnostic positions of gaze(Conjugate Ocular Movements)

o Look at the movement of the muscles withboth eyes open.

3. Convergenceo Move an object close to the face of the

patient until it breaks convergence. o Normally, when objects are moved closer,

the eyes will converge. o Nearpoint of convergence is when one

eyeswings laterally or moves so thatconvergence is no longer maintained.

4. Divergenceo Uses electromyographyo Seldom tested except in considering

amplitudes of fusion 5. Sensory exam- Mainly for depth perception, since

misaligned eyes do not have depth perception. Butthey can use ocular cues like when they cross thestreet, they know that the car is far away if it issmall and if it is big it is near, basically monocularcues only pero they cannot know exactly how farthe car is

o Stereopsis Testing: Random dotStereography, Titmus Fly Test

o Suppression Test: Worth Four-Dot Test, ifthe brain suppresses one eye

o Fusion Potential

TREATMENTObjectives:

Reversal of deleterious sensory effects ofstrabismus (amblyopia, suppression, and loss ofstereopsis)

o Not using eyes together= loss of stereopsis Best possible alignment of the eyes by medical or

surgical treatment.

Comitant strabismus is the most common type ofstrabismus. The individual extraocular muscles usuallyhave no defect. The amount of deviation is constant, orrelatively constant.

Pseudostrabismus (pseudoesotropia) is one of themost common reasons a pediatric ophthalmologist isasked to evaluate an infant. This condition ischaracterized by the false appearance of strabismus

when the visual axes are aligned accurately. Pseudoesotropia can be differentiated from a truemisalignment of the eyes when the corneal light reflexis centered in both eyes and when the cover-uncovertest shows no refixation movement.

Esodeviationsare the most common type of ocularmisalignment in children and represent >50% of allocular deviations. Congenital esotropiais a confusingterm. Few children who have this disorder are actuallyborn with an esotropia.This is a condition in whichthe child looks to the right with the left eye and to theleft with the right eye. With cross-fixation, there is noneed for the eye to turn away from the nose(abduction) because the adducting eye is used in sidegaze; this condition simulates a 6th nerve palsy.

The primary goal of treatment in congenital esotropiais to eliminate or reduce the deviation as much aspossible.

The two most common forms of vertical deviations todevelop are inferior oblique muscle overaction anddissociated vertical deviation. In inferior oblique muscleoveraction, the overactive inferior oblique muscleproduces an upshoot of the eye closest to the nosewhen the patient looks to the side . In dissociatedvertical deviation, 1 eye drifts up slowly, with no

movement of the other eye. Accommodative esotropiais defined as a “convergentdeviation of the eyes associated with activation of theaccommodative (focusing) reflex.” It usually occurs in achild who is between 2 and 3 yr of age and who has ahistory of acquired intermittent or constant crossing.

Exodeviationsare the second most common type ofmisalignment. The divergent deviation may beintermittent or constant. Intermittent exotropia is themost common exodeviation in childhood.


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Medical Treatment1. Treatment of Amblyopia

o Occlusion Therapyo Atropine Penalization

2. Optical Deviceso Spectacleo Prismso To align the eyes. Accommodative Type of

Esotropia: give glasses to correctmisalignment. It is the only type ofmisalignment that can be corrected withglasses.

o In some cases of strabismus where themisalignment is not very large, give prismsto eliminate misalignment.

3. Pharmacologic Agentso Miotics - Echothiophate

Iodide/Isoflurophateo Botulinum Toxin

Given in cases of paralyticstrabismus.Inject on affected eyemuscle for it to relax and fix positionon primary gaze. Eyes cannot movetemporarily (fixed on primary gaze)but double vision is eliminated.

4. Orthoptic Exercises

Surgical Procedures1. Resection- Strengthening

o For those with weak muscles, cut themuscle shorter and insert. Shorter musclewill be stronger than the lax longer muscle .

2. Recession- Weakeningo Cut muscle from its original insertion and

suture it farther away from its originalinsertion.

3. Shifting of point of muscle attachment4. Faden Procedure- Posterior Fixation

o Suture the belly of involved muscle andsuture it to the sclera.

Adjustable Sutures - not applicable if 2 years old little or no accommodative factor


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clinical findings are the same as for infantile ET TREATMENT is surgical

ACCOMMODATIVE common in 2 and 3 yrs. of age and who has a

history of acquired intermittent or constantcrossing

Amblyopia occurs in the majority of cases Occurs when:

o normal physiologic mechanism ofaccommodation

o overactive convergence responseo insufficient relative fusion divergence (not

enough signal from the brain to moveocular muscle)

o Fusion divergence- mechanism of brain tostimulate lateral rectus to pull eye outward.

Pathologic Mechanisms o Sufficient high hyperopiao High AC/A ratio, accompanied by mild to

moderate hyperopia- greater deviation at

near. normal AC/A (accommodationconvergence to accommodation): 3-5

Treatment: o Glasses with full cycloplegic refractiono The eyes are only straight when the patient

is wearing the glasses, when he takes it off,libat man cxa gihapon

o Bifocals for high AC/A ratio.

PARTIALLY ACCOMMODATIVE A mixed mechanism

o Part muscular imbalance and partaccommodative/convergence imbalance

Surgery: only in non-accommodative component

PSEUDOTROPIA false appearance of strabismus when the visual

axes are aligned accurately Oriental eyes like Koreans, Japanese, Chinese, daw

libat sila lantawun pero once you do assessmentyou realize nga perfectly straight man ila eyes

Usually caused by a flat broad nasal bridge andprominent epicanthal fold or a narrowinterpupillary distance.

Corneal light reflex is centered in both eyes andwhen the cover-uncover test shows no refixationmovement unlike in true misalignment of the eyes

Usually outgrows with time; reassessment isrequired if the apparent deviation does notimprove.

INCOMITANT 6th nerve palsy (paretic lateral rectus)- most

common cause, since 6 th nerve is a very long nervealmost any head injury could injure it

Medial rectus restriction Due to: trauma, systemic HPN, DM, Tumors Treatment :

o observe for 6 months, usually returns tonormal

o botulinum A toxino surgery if persistent

EXTROPIA less common exophoria – intermittent - constant alternative classification:

o basic exotropiao divergence excess (misalignment ofexcess

in distant than near vision) o pseudodivergence excess (divergenceequal

after 30 mins of patch test) o convergence insufficiencies

(divergencebigger in near than distantgaze)

INTERMITTENT >50% of all cases of exotropia most common exodeviation in childhood Onset at 1 st year, most have presented by age 5

(according to Nelson between age 6 mo. and 4yrs. )

progressively worsens Characteristic Sign : closing one eye in bright light

o reflex closure of the exotropic eye outward drifting of one eye which usually occurs

when child is fixating at distance

deviation is generally more frequent with fatigue or illness visual acuity tends to be good in both eyes and

binocular vision is initially normal Usually no gross sensory abnormalities Treatment :

o Medical - refractivecorrection andamblyopia therapy.

o Surgical - bilateral lateral rectus recessiono treat diplopia first before surgery because it

has better prognosis than the other wayaround

CONSTANT less common than intermittent exotropia may be of any degree with chronicity or poor VA, the deviation become

large Amblyopia is uncommon Treatment: surgical

AMBLYOPIA unilateral/bilateral reduction of visual acuity that

cannot be attributed directly to the effect of any


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structural abnormality of the eye or of any of theposterior visual pathway

m ay occur only during the critical period ofdevelopment, before the cortex has becomevisually mature, within the first decade of life

due to abnormal visual expression in early life:visual maturity- 7 to 10 years old

Ocular misalignmentUncorrected refractory error

3. Other disorders that degrade the quality ofimages transmitted to the brain from theeye (e.g. congenital cataract, congenital

ptosis, etc.)

CLASSIFICATION 1. Strabismic: most common

o Esotropia o Exotropia o Hypertropia, hypotropia

2. Anisometropic- 2 ndcommon, most difficulttodetect, one eye sees very well while the other eye

cannot see well o Hyperopic o Myopic o Antimetropic o Astigmatic

3. Isoametropic (both eyes have very highrefractiveerror)

4. Deprivationo Cataract o Ptosis o Nystagmus o Occlusion

Mechanisms: abnormal early visual experience - loss or

decreased responsiveness of primary visual cortexto visual stimuli

neuron loss in lateral geniculate body involvement at the retinal level

MANAGEMENT Diagnosis: decreased visual acuity that cannotbeexplained by physical abnormalities

Treatment:

Cataract removal - 1 st to 2 nd months of life Refractive correction (cycloplegic refracts) Occlusion and optical degeneration ( cover good

eye for certain hours duringthe day so that thebrain will be forced to use the bad eye)

o full term/ part time patchingo atropine penalization, substitute for

patching o put atropine on the good eye so that it will

have a poorer visual acuity than the bad

eye; not applicable to all like if the bad eyehas a visual acuity of x/200

o make sure that the vision of the good eyewill be worse than the bad eye

Complications: over treatment

o reverse/iatrogenic amblyopia

Desired End-Point Therapy: free spontaneous alteration of fixation linear snellen acuity differ by no more than one

line between 2 eyes

STOP TREATMENT - if no progress is noted overa periodof 3-6 months with good compliance.

Not discussed DUANE SYNDROME

Rare congenital disorder of eye movement which ischaracterized by retraction of the globe onadduction

Diagnosed by age 10 a miswiring of the eye muscles that causes some

eye muscles to contract when they should not andother eye muscles not to contract when theyshould attributed to the absence of the 6th nervenucleus and anomalous innervation of the lateralrectus muscle, which results in co-contraction ofthe medial and lateral rectus muscles onattempted adduction of the affected eye

Female/ male ratio: 3:2 History of the following: o Strabismus o

Head tilt o Loss of binocular vision o Reduced abduction o Picture of paralytic squint

Type 1 limited eye abduction with normal or near normal

adduction The palpebral fissure narrows, and the eyeball

retracts into the orbit during adduction; reversehappens during abduction

Type 2 adduction of the affected eye is limited, whereas

abduction of the eye is normal or only slightlylimited

The palpebral fissure narrows, and the eyeballretracts into the globe when the affected eyeattempts to adduct.

Type 3 adduction and abduction of the affected eye is

limited The palpebral fissure narrows, and the eyeball

retracts when the affected eye attempts toadduct.


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Further divided into 3 subgroups: Subgroup A: affected eye is turned inward toward

the nose (esotropia). Subgroup B: affected eye is turned outward

toward the ear (exotropia) Subgroup C: eyes are in a straight primary

position.

Treatment: surgery to improve alignment or to reduce anoticeable face turn can be helpful

MOBIUS SYNDROME congenital facial weakness combined with

abnormal ocular abduction, may be unilateral orbilateral

facial palsy is commonly bilateral, frequentlyasymmetric, and often incomplete, tending tospare the lower face and platysma

Ectropion, epiphora, and exposure keratopathymay develop

high incidence of associated congenitaldeformities: club foot (most common), brachialdeformities, pectoral muscle hypoplasia, ptosis,palatal and lingual palsy, hearing loss, lingualmuscle defects, micrognathia, syndactyly,supernumerary digits, and the absence of hands,feet, fingers, or toes.

US prevalence: 0.002-0.0002% of births, or 1 caseper 50,000 newborns

Treatment: surgical correction of the esotropia isindicated and any attendant amblyopia should betreated.

Proposed Groups: *no clinical significance Group I - Simple hypoplasia or atrophy of CN

nuclei Group II - Primary lesions in peripheral CNs Group III - Focal necrosis in brainstem nuclei Group IV - Primary myopathy with no central

nervous system (CNS) or CN lesions

ORBITAL ABNORMALITIES Craniofacial dysostosis (Crouzon's disease)

rare hereditary deformity; autosomal dominant Characterized by: exophthalmos, hypoplasia of the

maxilla, enlargement of the nasal bones, abnormalincrease in the space between the eyes (ocularhypertelorism), optic atrophy, and bonyabnormalities of the region of the perilongitudinalsinus. The palpebral fissures slant downward (incontrast to the upward slant of Down's syndrome.

Strabismus secondary to both structural anomaliesof the muscles and orbital angle anomalies

UVEITIS IN CHILDHOOD

Inflammatory eye disease is uncommonConditions that are the same in adults:

o Acute nongranulomatous anterior uveitisassociated with HLA-B27 spondylarthritides

o Intermediate uveitiso Fuchs' heterochromic cyclitiso Idiopathic anterior uveitis

Uveitis in association with Juvenile RheumatoidArthritis

o Asymptomatic in early stageso Loss of vision due to glaucoma, cataract or

band keratopathyo Regular ophthalmic screeningo Long term use of topical steroid and

mydriatics

Documents

B20M02L05Childhood Eye Diseases