BV OSCE Flashcards

Question

Consecutive exotropia

Answer 1

-XOT follows previous esotropia/phoria -often constant -may occur spontaneously (no BSV & amblyopia) -often after surgery for eso deviation (over correction by surgeon) -management: under 8 years (refer) to prevent loss of BSV or amblyopia

Answer 2

-Initial defect was the XOT -Constant or intermittent

Answer 3

-XOT under all viewing conditions -ensure nil pathology or neurological disease particularly <2 years -consider refer to HES -amblyopia may develop if occur early MANAGEMENT: -treat amblyopia -BOTOX-into lateral rectus muscle -surgery- MR AND LR in affected eye, adjustable sutures in px with diplopia

Answer 4

more common in adults than children -more likely to complain of diplopia -may complain of problems for near work (headaches, diplopia, asthenopia symptoms) -cover test (near xot, distance controlled (phoria) Management: -under correct hyperopic rx -prism- base in -surgery-bilateral medial rectus resection

Answer 5

-intermittent XOT/BSV at any distance of viewing -can present in any age group -diplopia unlikely-usually suppression occurs -Management- refer for surgery

Answer 6

-near=BSV -distance-intermittent or constant XOT -most common in children -suppression normally occurs when manifest-diplopia rare -may close one eye in bright light Distance XOT split into 1. True distance XOT -near BSV -distance XOT 2. simulated distance XOT -want to break into XOT at near but controlled by accommodation (high AC/A Ratio), which is eliminated by +3.00DS causing them to become manifest at near -controlled at near by fusion which is eliminated using patching Differential diagnosis- carry CT after 45 minutes of occlusion if deviation controlled at near after occlusion, then true, if near manifest after occlusion than simulated Management: -prism- base in relieving -minus lenses-particularly those with high AC/A -surgery

Answer 7

1. history -age of onset-how young -frequency (constant-intermittent) -symptoms (when? Near-distance) -family history -POH (glasses, amblyopia, secondary XOT, consecutive XOT) -GH 2. VA -amblyopia (common in constant, common in consecutive XOT) -secondary exotropia from ocular pathology and amblyopia equals reduced VA 3. cover test -enables differentiation of different types -do at near, distance -accommodative target and a light -if XOP present then note size of deviation -record fixing eye/alternating -CT with +3.00DS after occlusion to determine real or simulated distance XOT 4. ocular motility - XOT manifest on elevation -consecutive XOT look for surgery scars 5. near point convergence -important indicator of control for near 6. BSV -sensory fusion -stereopsis at distance which they are controlled -fusional reserves 7. measure angle of deviation using PCT 8. measurement of suppression -post-op diplopia test which simulates to patient what it’s like to have surgery 9. cycloplegic refraction and fundus and media examination

Answer 8

Functional cure-restore BSV Reconstructive cure- NO BSV- improve cosmesis -refraction, fundus, and media -correction of ametropia -amblyopia therapy particularly under 7 years of age -Rx- under correct hyperopia (as plus relaxes accommodation and eyes move further) -Rx- full minus - prisms (base in – near XOT) -presbyopia -orthoptic exercise to improve near point of convergence such as dot card -surgery (reconstructive, functional surgery to restore BSV) -consider refer for all under 8

Answer 9

Anatomy: originates in the pons at the oculomotor nucleus-passes through the circles of willis - runs parallel to the posterior communicating artery (PCA)-through the cavernous sinus and splits in the superior and inferior divisions Superior division innervates (superior rectus and the levator), and inferior division innervates (medial rectus, inferior rectus, and inferior oblique) Causes: posterior communicating artery aneurysm, trauma (closed head injury), vascular (diabetes and hypertensive), inflammation or infection, congenital Symptoms: sudden onset of unilateral ptosis, ocular pain, headache, diplopia Features of total 3rd CN palsy -affected eye is down and out (exotropia and hypotropia) -pupil maybe dilated -ptosis -accommodation is reduced or absent -limited elevation and depression and adduction -normal abduction

Answer 10

-congenital most common -superior rectus and levator affected -eye hypotropic with ptosis -CHP- chin up, face turn to unaffected side -muscle sequelae- O/A of IO, IR and SO

Answer 11

-medial rectus, inferior rectus and inferior oblique, sphincter pupillae and ciliary muscle affected -eye exotropic, intorted, hypertropic -muscle sequelae- O/A of LR, SR and SO -accommodation affected

Answer 12

-3rd cranial nerve runs parallel to the PCA -aneurysms on PCA will cause pupil dilation -in 62-83% of total 3rd CNP pupil is spared, pupil sparing = ischemia -pupil involvement = compressive lesion -Ptosis then diplopia spared Treatment: emergency refer to HES, children under 8 (amblyopia therapy), occlusion patch if diplopia, surgery

Answer 13

Anatomy: the trochlear nerve originates in the nucleus in the mid brain at the level of the inferior colliculus and proceed posteriorly and crossover before making their way to the eye (longest and thinnest nerve)-passes through the circle of willis Innervates SO, longest, and thinnest nerve so easily damaged in soft head or body trauma Congenital or acquired (trauma, vascular aetiology) Bilateral unless proven otherwise

Answer 14

-affects SO -eye hypertropic and esotropic -may control hypertropia with CHP- chin depression, face turn to affected eye, head tilt to unaffected side -adaptation to torsion -unilateral hyperdeviation in PP -no reversal on OM/BHTT

Answer 15

Brown’s syndrome-V eso pattern -significant extorsion- vertical/torsional diplopia the greatest symptom -CHP-chin depression -reversal of hypertropia on dextrodepression and laevodepression

Answer 16

Anatomy: the abducens nerve originates in the nucleus in the pons ventral to the floor of the fourth ventricles-moves vertically and a 90-degree bend over the petroclinoid ligament to the lateral rectus -6th cranial nerve has a long course, compression as the nerves passes over petrous temporal bone due to raised ICP, aneurysms, space occupying lesion -innervates lateral recuts prone to damage due to raised intra-cranial pressure -lateral rectus pulls eyes out and the greatest effect on distance fixation Acquired: -more common in adults -caused by microvascular, trauma, neurological such as MS Congenital rare -transient in new-borns -related to traumatic birth -often resolves -Duanes syndrome: congenital absence of the 6th CN Symptoms: horizontal diplopia, headache Clinical features -esotropia greater for distance -limitation of abduction on the affected side -adoption of AHP- face turn to the affected side to achieve binocularity -unilateral or bilateral -field of BSV displaced to the unaffected side Muscle sequelae -UO of LR -OA of MR Management in children -establish cause: MRI and referral to neuro Important BSV not lost and prevent amblyopia (encourage CHP, BTXA to MR) Management in adults -occlusion in patients with recent onset and large angle esotropia -Fresnel prisms -surgery to resolve diplopia in PP

Answer 17

3rd CN palsy with pupil involvement- lesion that compresses the 3rd CN supply and also compresses parasympathetic nerve fibres which travel along its surface - signs: complete ptosis, diplopia, hypotropia and exotropia, restricted parasympathetic supply inhibits constriction, anisocoria (unequal pupil size) increase in bright light, affected pupil is dilated and unreactive and near reflex also absent -cause: enlarging aneurysm on PCA, trauma, tumour -without pupil involvement: generally vascular in origin related to diabetes or HTN congenital 3rd CN palsy (IR, IO, SR, MR) -causes: familial, perinatal trauma, familial migraine -characteristics: hypotropia, exotropia, intact pupil reflexes, ptosis, limitation of elevation, depression, adduction acquired 3rd CN palsy (IR, IO, SR, MR) -causes: tumours, trauma, inflammation, and vascular lesions of the brain -symptoms: sudden onset of unilateral ptosis, ocular pain, headache, diplopia -characteristics: pupil sparing suggests ischaemia, pupil involvement suggest compressive lesion, exotropia, hypotropia, ptosis, limitation of elevation, depression, adduction 4th CN palsy (SO) -causes: congenital or acquired (tumours, trauma, inflammation) -characteristics: vertical diplopia, hypertropia, CHP to lower eye Acquired 6th CN palsy -causes: tumours, trauma, inflammation, and vascular lesions of the brain, high ICP -symptoms: horizontal diplopia, headache -signs: esodeviation that is greater at distance, isolated abduction deficit, abnormal CHP

Answer 18

-A rhythmic oscillation of the eyes, which can be physiological or pathological, it can be symmetrical, asymmetrical, unilateral, or bilateral -can be horizontal, vertical, torsional or a combination -Benign idiopathic (congenital) nystagmus is secondary to visual deficit such as retinal dystrophies and neurological deficit such as intra-cranial lesions -manifest nystagmus: present when both eyes are open may increase when one eye is covered -latent nystagmus: when one eye is covered, steady fixation with both eyes open -null zone: the eye position where the nystagmus intensity (amplitude x frequency) is least Description: observe Px in PP for 20 secs classify by position, type, rate, plane, and null zone

Answer 19

1. Cerebellar jerk nystagmus: Nystagmus is jerky with large amplitude and low frequency; nystagmus increases when eyes look in the direction of fast phase Signs: headaches, limb weakness, disturbed speech 2. down-beat nystagmus: nystagmus in pp with the fast phase downwards. Lateral gaze accentuates the nystagmus. Causes: stroke, MS, alcohol 3. see-saw nystagmus: torsional nystagmus in pp. When one eye elevates and intorts and the other depresses and extorts. Typical lesion in chiasmal region 4. congenital pendular nystagmus: horizontal/vertical and rotary. Nystagmus decreases on convergence and increases on covering of one eye, AHP Anterior segment: congenital cataract, Aphakia, albinism Posterior segment: ON hypoplasia, foveal hypoplasia

Answer 20

uncontrolled eye movements, visual problems, dizziness, reduced depth perception or balance problems

Answer 21

glasses to ensure best possible corrected vision, contact lenses as they move with eye, low vision aids such as magnifiers to help with reading, prisms, drugs such as cannabis, BOTOX, surgery

Answer 22

surgery to EOMs to move null zone to primary position, prisms to move visual environment to null position

Answer 23

-ocular fatigue -systemic fatigue -diurnal variation as the day progresses (so might be better on wake) -weakness increases after exercise -common in younger females and older males -lack of facial expression Ocular signs and symptoms 1. Ptosis: initial signs, usually bilateral and asymmetrical, increases with fatigue, frontalis over-action is often seen in attempt to elevate eye, lid retraction in an attempt to elevate the eye Investigating ptosis: request Px to elevate their eyes for 1-2 minutes, severity of ptosis increases when eyes return to PP Cogan’s lid twitch: -request px to depress eyes for 15 secs, on return to PP lid initially elevate above ptotic level before returning to normal position Gorelick’s sign: -in asymmetrical cases hold the more ptotic lid and the ptosis on the opposite side will increase 2. diplopia: variable may change horizontal to vertical, px may report that images separate further as fatigue increases, may mimic palsies, and change which muscle is affected 3. orbicularis weakness: can usually close eyes, may not be able to bury eye lashes, unable to stop examiner opening eyes with gentle pressure Treatment: ptosis props, occlusion such as frosted lens, surgery is contraindicated due to instability

Answer 24

-congenital -females>males -abnormal horizontal eye movements (unilateral more common) Aetiology -neurogenic: abnormal innervation to LR -myogenic: fibrosis or inelasticity of the LR and MR muscle inserts abnormally Clinical signs -complete or less often partial absence of abduction -partial loss adduction (sometimes) -deviation in PP (Eso/Exo) -CHP: face turn affected side for distance, face turn to unaffected side for near -poor convergence -A or V pattern -reduced binocular function -up or down shoot on adduction -globe retraction on adduction Classification of Duane’s syndrome . Type A- loss Abduction>adduction . Type B- loss abduction only . Type C- loss adduction>abduction Type A -limitation on ABDuction with less marked limitation of ADDuction -may have esotropia -widening of palpebral fissure on ABDuction and narrowing and globe retraction on ADDuction Type B -limitation of ABDuction, normal ADDuction -may have associated esotropia -widening of palpebral fissure on ABDuction and narrowing and globe retraction on ADDuction Type C -limitation of ADDuction>ABDuction -usually exotropic -globe retraction on ADDuction

Answer 25

. coloboma, lens opacities, heterochromia, deafness, cleft palate Management -urgent referral if under 8 (check ocular/systemic association, ensure BSV maintained, treat amblyopia) -if BSV good and cosmetically acceptable CHP then observe only -if CHP causing neck problems or poor cosmesis-surgery to enhance abduction ability -if manifest in primary position, then prism and surgery

Answer 26

Acquired: trochlear damage (traumatic, inflammatory), SO tendon abnormalities (inflammatory) signs -limited elevation of the eye on ADDuction with normal depression in ADDuction -limited elevation in direction elevation and ABDuction Symptoms -pain/discomfort -diplopia -CHP -unable to elevate eye -90% unilateral Characteristics -unilateral, most px have BSV but some has strabismus in PP -limitation of elevation in ADDuction, ABDuction, and direct elevation -A or V pattern, CHP head tilt to affected eye or chin elevation in bilateral Brown’s -down drift of affected eye -over action of SR Treatment Non-surgical- if BSV present and deviation well compensated observe and monitor BSV Surgical-possible contralateral superior rectus

Answer 27

Symptoms -discomfort: drying of corneal epithelium, proptosis, lid retraction, swollen conjunctiva -loss of VA: cornea exposure, optic nerve compression -diplopia: vertical/horizontal due to oedema and EOM fibrosis Signs -lid retraction -lid lag on down gaze -proptosis oedema -IR most commonly affected then MR (esotropia and hypotropia) -CHP to increase BSV -conjunctival chemosis -corneal erosion Graves ophthalmology -this refers to the inflammatory response and its sequelae in and around the orbit associated with autoimmune thyroid disease -most associated with hyperthyroidism but does occur with hypothyroidism Treatment Active treatment: steroids, surgical decompression, radio therapy, ocular lubricants Inactive treatment: prism therapy, surgery to increase BSV, lid retraction surgery

Answer 28

Types of convergence anomalies: 1. convergence insufficiency: inability to obtain adequate binocular convergence without undue effort - Factors causing convergence insufficiency: illness, fatigue, near work, constant distance vision - Secondary causes of convergence insufficiency: heterophoria, uncorrected refractive error, accommodative insufficiency, pathology such as thyroid eye disease - Symptoms of convergence insufficiency: headaches, eyestrain, asthenopia, diplopia, blurred vision (XOP decomp) and diplopia - CT: XOP/XOT at near, orthophoria distance - Test subjective (when patient reports diplopia) and objectively (watch patients’ eye for convergence to break) -likely to have low base out fusional reserve at near -other investigation (measure deviation with PCT, VA, stereoacuity, OM if incomitant refer, fundus and cyclo) -management: treat any pathology, significant refractive error corrected and exercises such as dot card 2. convergence fatigue: inability to maintain convergence overtime - Symptoms of convergence fatigue: symptoms occur after prolonged near work - CT: normal at near and distance but after prolonged dissociation with occluded a tropia or phoria might appear at near - base out at near reduces on prolonged testing 3. convergence paralysis: the ability to converge closer than infinity is entirely lost -primary -secondary (closed head injury, viral illness, occlusive vascular disease) - at distance closer than infinity (Nil convergence, XOT, crossed dip) -if no convergence, pupillary response may absent -nil base out fusional reserves -management: urgent referral, occlusion, Botox, base in prism to correct XOT 4. convergence accommodative/spasm -spasm of convergency usually causes spasm of accommodation and miosis -convergence spasm (MR may become contracted) -accommodative spasm (ciliary muscle becomes contracted) -causes (over treatment of CI, uncorrected hypermetropia) -signs and symptoms: could result in SOT, blurred vision in distance, pupil miosis, headache, lead on dynamic ret Differential diagnosis: if px has greater esotropia in the distance, important to rule out 6th nerve palsy (check OT, check pupils normal) Management: pathology treated, cycloplegic, give full hyperopic correction to relax accommodation, BOTOX

Answer 29

- near point assessed with RAF rule in dioptres - assessed three-times insufficiency vs fatigue - assessed monocularly and binocularly If accommodation is normal monocularly but binocularly not, then it suggests convergence insufficiency instead of accommodative insufficiency Dynamic retinoscopy (objective test) MEM method

Answer 30

1. accommodative insufficiency/fatigue - Aetiology: high hyperopia, illness, trauma, children with down’s syndrome - Symptoms of accommodative insufficiency: blurred vision at near, asthenopia, micropsia -if accommodative fatigue then symptoms after prolonged near work - Signs of accommodative insufficiency: XOP or SOP at near (because of effort to accommodate), reduced near point accommodation for age, dynamic ret (shows lag), reduced accommodative facility - Management: correct hyperopia, exercises, and downs syndrome (bifocals) 2. accommodative paralysis Aetiology: head injury, trauma -no accommodation can be exerted, blurred vision for distances closer than infinity - Management: urgent refer 3. accommodative inertia: difficulty changing focus, blur when changing from near and distance but clear -associated with presbyopia and developing cataract -symptoms: complains of blurred vision when changing from near to distance -management: full hyperopic correction, orthoptic exercises (flippers, jump accommodation)

Answer 31

when both eyes are uncovered the visual axis are directed towards the fixation target -when the eyes are dissociated the eyes deviate from the fixation point -can be concomitant (angle of deviation same in all directions of gaze) or incomitant (angle of deviation differs in different directions of gaze) -can be decompensated (patient usually symptomatic) or compensated (patient symptom free)

Answer 32

-Divergence excess exophoria (D>N) - exophoria which is increasing in the distance -convergence weakness exophoria-exophoria which is larger at near (N>D) – failure to converge so px is exophoric

Answer 33

-Divergence weakness esophoria– esophoria which is larger in the distance -convergence excess esophoria – esophoria which is larger at near

Answer 34

-under corrected refractive error so esophoria (uncorrected hypermetropic refractive error) and exophoria (uncorrected myopic refractive error) -surgery -pathology Symptoms of heterophoria: due effort to maintain BSV (headache, eyestrain, and asthenopia) or due to failure to maintain BSV (diplopia, blurred vision)

Answer 35

-History (when did they start, how regular, are they progressing, do they become worse when doing particular activity, can they be stopped) -GH -POH (cataract surgery, strabismus, surgery) -VA -CT -OT -convergence (RAF rule repeat 3 times to make ensure convergence insufficiency not convergence fatigue) -accommodation (near point), dynamic ret

Answer 36

alleviate symptoms, prevent phoria from breaking down into tropia 1. removal cause of decompensation-long hours of close work, poor illumination or contrast, sudden increase in the amount of close work 2. modifying Rx- full plus for esophoria and hyperopia

Answer 37

Failure to converge to 6cm or failure to reach 10cm comfortably without fatigue -associated with exophoria at near and asthenopia and diplopia

Answer 38

1. jump convergence: 2 targets at least 3m apart -px fixates on near target and focus on it to maintain single image -swap fixation to distance target to ensure single -repeat process several times 2. Dot card -slim rectangular piece of card with equal spaced dots -card held to nose at slightly depressed position -px fixates at the furthest dot and so on and maintain single image -repeat 3-5 cycles

Answer 39

accommodative insufficiency and fatigue are characterised by reduced amplitude of accommodation in relation to the patients age and signs of fatigue -treated using exercises 1. jump accommodation -similar to jump convergence -targets at two distances except target held at nearest point of blur 2. accommodative push-up -an accommodative target such as a letter on the budgie stick held at arm’s length -target moved closer at consistent speed and attempt to maintain BSV -once image blurs and cannot be kept clear return to original position -repeat 3-5 times 3. lens flippers (+/-1.00, +/-1.50, +/-2.00) to increase number of rotations they can see -suggest 1-2 mins x3/day

Answer 40

1. occlusion therapy 2. optical penalization 3. cycloplegic drugs such as atropine

Answer 41

-Factors to consider when treating amblyopia: age of onset, duration of amblyopia, type of amblyopia, other pathology, compliance -occlusion period: vision 6/9 to 6/24- 2 hours of patching- vision less than 6/24 = 6 hours of patching -the importance of treating amblyopia: DVLA requirements, pathology to good eye in later life, critical period -advantages of occlusion: cheap, can specify time, can use in severe amblyopes -disadvantages of occlusion: poor cosmesis, compliance, allergy to Elastoplast

Answer 42

-Blurs VA in better eye sufficient to make the worse eye work -this treatment is for those who can’t tolerate occlusion therapy -this is achieved with alteration of spectacle correction or cycloplegic drugs Near penalization: Encourage use of amblyopic eye for close work- instil cycloplegia usually atropine in good eye to stop accommodation and give +3.00 to good eye Distance penalization: Encourage use of amblyopic eye for distance, add +3.00 to good eye to blur Total penalization: Encourage use of amblyopic eye at all distance- strong convex lens or cycloplegic and strong concave lens -atropine alone does not work for severe amblyopia

Answer 43

atropine ointment/drops Advantages: good cosmesis, as effective as occlusion in treating moderate amblyopia, used when VA doesn’t improve with occlusion therapy Disadvantages: px may be allergic, interaction with systemic medication, cannot be used in severe amblyopia, constantly blurred vision, not suitable for older strabismic amblyopes Review: review every 3 months, younger px reviewed more regularly

Answer 44

1. stimulus deprivation amblyopia: -treat primary pathology (e.g. cataract) -full Rx and constant wear -total occlusion preferable 2. Strabismic amblyopia -full time glasses wear -occlusion or atropine -consider inverse occlusion if eccentric fixation 3. anisometropic amblyopia -full time glasses wear -no need for occlusion if VA consistently improving Complications: Intractable diplopia, occlusion amblyopia, failure of VA to improve, increase in angle of deviation, allergy to atropine Compliance: build up good relationship, explain critical period, explain to child what is happening, ask child which eye to wear patch

Answer 45

-working distance 38cm -usually 15 cards with black and white stripes on right or left side, 1 blank card -4mm hole in centre where practitioner looks through -starts with low spatial frequency (wider stripes) -correctly identifies the same stimulus twice means the child can resolve that card

Answer 46

-based on vanishing optotypes -pictures: (duck, house, fish, car, train, boat) -3 cards for each of the 11 acuity levels (2 out of 3 responses correct move on to next) -no crowding (nothing surrounding the pictures) -may overestimate VA -50cm or 1m depending on age -present the cards with widest target which is the lowest acuity at eye level

Answer 47

-preferential looking test -2 forced choice or 4 forced choices -child must touch the pattern -working distance 25-50cm -VA measured 0.2-1.3 LogMAR

Answer 48

-Recognition ability: Ability to detect, resolve and recognise a target -more sensitive to amblyopia defects 1. Kay pictures -used for children between 2-4 years -pictures of common objects known to a child -single or crowding in LogMAR (3m) – 1.0-0.1 LogMAR -single picture in Snellen (3m or 6m) – 6/6 – 6/60 2. Keeler LogMAR crowded test -used for children between 3-5 -3m -Flipchart -6/36-6/3 -screening and uncrowded test

Answer 49

Kay pictures near test at 33cm, Lea symbols near vision at 40cm

Answer 50

1. Cardiff contrast sensitivity test 50cm -vanishing optotypes -three cards at each contrast level from 46% to 1% in 12 steps -12 months onwards 2. Hiding Heidi -five contrast levels -two cards: white and one with “Heidi” -child must point to where Heidi is -0 months onwards -variable working distance

Answer 51

-RFV -FLOADs to any concerns/worries -POH (patching, squint, amblyopia, HES) -FOH (patching, strab, any ocular conditions in the family) -Birth history (type of delivery, full-term) -Medical history, Medications, Allergies

Answer 52

-20 Dioptre base out prim to measure fusion (BO prism is held before either eye at 33cm, eye behind prism should adduct rapidly to restore fusion and abduct on removal) -4 dioptre base out – test for macula suppression -sensory fusion (worth 4 dot test, Baglioni lenses) -NPC to measure convergence -Stereopsis -Accommodation (RAF rule, flipper lenses, Accommodative lag, or lead)