Paediatric Ophthalmology for Med Students
Dr. Norasyikin Mustafa MBBCh (Dublin), M Oph (UM)
Lecture Outline • • • • • • • •
Visual milestone Refractive error Squint Amblyopia White pupil (congenital cataract/Retinoblastoma) Congenital glaucoma Retinopathy of Prematurity (ROP) Other common problems : Vernal keratoconjunctivis, strawberry naevi, nasolacrimal duct obstruction
VISUAL MILESTONE
Age
Expected VA
Visual development
0-1 months old
6/240-6/180
Turns eye towards light, eye contact by 6 weeks, fixate and follow
2-3 months
6/120
Response to smile, steady fixation, interested in moving objects
3-6 months
6/60
Observe toys falling and rolling, recognise facial expression, shift fixation across midline, plays with own hand
7-10 months
notices small bread crumbs, first touches, then develop pincer grasp, interested in pictures recognise partially hidden objects
11-12 months
6/36
point to desired object,visual orientation at home look through windows, recognise familiar figures in the distance/recognise pictures, play hide- and- seek scribble with a crayon
12-24 months
6/36-6/18
Able to match objects and imitate movements.
2-5 years old
6/18-6/6
Read alphabets
Warning Signs of Visual Impairment A. Appearance • • • • •
Wandering eye (no fixation) Dancing eye (nystagmus) Not responding to bright light Eyes turn in or out (squint) White pupil
Warning Signs of Visual Impairment B. Behaviour • • • • • • •
Tilting head to one side Squinting or frowning Excessive blinking Excessive rubbing of the eye Closing or covering one eye Confusion with alphabet Watching TV and reading to close
Warning Signs of Visual Impairment C. Complaint • • • • • •
Headache, nausea or dizziness Blurred vision Double vision Blurry vision when looking up after close work Unusual sensitivity to light Burning, scratchy or itchy eyes
Visual acuity testing Recognition acuity
Resolution acuity
• Kay pictures
•
Optokinetic nystagmus – 20/400 or better
• LEA symbols •
Preferential looking test eg Teller card
•
Cardiff acuity card
•
VEP
• Sheridan Gardner chart
• Snellen chart
Checking Vision in Children
Infant 6 weeks
6-18 months old
1-3 years old
2-4 years old
3-5 years old
4 yrs old and above
Fixate and follow
100s and 1000s
Cardiff Card
Kay Pictures
Sheridan Gardner chart
Snellen chart
Refractive error
Eyeball • Adult: 24mm (21-27mm) • At birth: 16-17mm • The eyeball grows rapidly increasing to 22.5-23mm by 3 years old • Full size by 13 years old
Refractive error • Myopia (short-sighted)
• Hyperopia (long-sighted)
• Astigmatism
• Anisometropia
Refractive error
• Usually improves with pinhole • Can be treated by glasses • Generally contact lens or refractive surgery not advisable in children
Ocular misalignment Squint Strabismus (Greek) Crossed eyes
Types of squint
Esotropia
Exotropia
Hypotropia
Hypertropia
Tropia vs Phoria • Tropia: ALWAYS deviated • Phoria : SOMETIMES deviated Exotropia vs exophoria Esotropia vs esophoria
Strabismus Hirschberg (corneal reflex) test: • is a screening test that can be used to assess whether a person has strabismus (ocular misalignment). • You shine a light at the eyes and observe where the light reflex is located in reference to the pupil. • In general, for every mm that the light is decentered, the eye is turned about 15 diopters.
Eyes are straight Orthophoria
Left esotropia Reflex between pupil margin and limbus
Left eye turns in/Convergent/ esotropia Reflex near pupil margin
Left esotropia Reflex at the limbus
Cover test Cover left eye: No movement of the right eye
Cover right eye: Left eye moves out to take up fixation
Uncover the right eye: Left eye moves in again
Squint: Assessment • Check visual acuity • Check refractive error. Hypermetropia? Myopia? Astigmatism? Anisometropia • Perform cover test • Assess extraocular muscle movement. Any restriction of EOM? • Dilated fundus examination. Rule out ocular pathology
Squint: Management • •
•
•
Proper assessment of degree of deviation Causes of squint – If has refractive error: Optical correction – If has obstruction E.g. cataract – surgical removal of the cataract (lens aspiration) Patch the good eye – to force the deviated eye to fixate (to prevent/reverse amblyopia if treated during the sensitive period of visual development ie <8 yo) Surgical correction – to change angle of deviation
AMBLYOPIA
Amblyopia • Vision loss without obvious organic cause • Definition: Decreased visual acuity in one or both eyes due to abnormal development of vision in infancy or childhood. • Vision loss occurs because nerve pathways between the brain and the eye are not properly stimulated • Vision is not improved with glasses and fundus looks normal. • Must be corrected before age 8-10 years old (the sensitive period of visual development)
3 types of amblyopia
Strabismic amblyopia • Squint
Refractive amblyopia • Refractive error
Deprivation amblyopia • Ptosis • Cataract
WHITE PUPIL WHITE REFLEX LEUKOCORIA/LEUKOKORIA
Congenital Cataract
Congenital cataract: causes • • • • • •
Metabolic disorder e.g. galactosaemia Intrauterine infections: Rubella, Toxoplasmosis, Varicella Hereditary AD, AR, X-linked Chromosomal disorders e.g. Down’s syndrome Ocular abnormalities e.g. microphthalmos, aniridia Idiopathic
Congenital cataract • Presentation: leukocoria. Eccentric fixation/squint. Roving eye movement • History: Family hx, birth trauma, Maternal hx: DM? Infection. Drug exposure. Radiation. • O/e: Visual acuity. Cataract- visually significant? Laterality • Type of cataract e.g. oil-droplet cataract (galactosaemia) • Investigations: FBC, RP, TORCHs screening
Congenital Cataract Associated Ocular Anomalies
Associated Systemic Anomalies
Microphthalmos (rubella)
Chromosomal (Down’s)
Mesenchymal dysgenesis, aniridia
Skin rashes (atopic dermatitis)
Glaucoma (Rubella)
Renal disease (Lowe’s, Alport’s)
Uveitis (JRA)
Cataract Surgery • Timing: – Bilateral severe: 2-3 months, operate fellow eye in 1 week – Unilateral severe: before 2 months – Bilateral or mild unilateral: wait until child is older
• Surgery – Lens aspiration and primary posterior capsulotomy – IOL or no IOL implant??? • No IOL if <2 years old but can consider if >6 months old • IOL power selection: aim for emmetropia? Myopia? • If no IOL implant: Aphakic correction by glasses/contact lens. Secondary IOL implant at school age.
Problems in Congenital Cataract Surgery • Intraoperative problems – Risk of GA – Small eye, anatomically different – Low scleral rigidity – Elastic anterior capsule
• Postoperative problems – Intense inflammation – Posterior capsule opacification – IOL decentration – Frequent refractive assessment
Retinoblastoma • Most common eye cancer in children • 1 in 14,000 live births • Genetic mutation on chromosome 13 (13q14) • Unilateral 67%, bilateral 33% • 2 types of mutation – Germline mutation – is the occurrence of Rb mutation on all cells in the body including retina and systemic sites. Usually bilateral and at risk of second cancer. – Somatic mutation – is the occurrence of Rb mutation only in the retina in one clone of cells. Unilateral, sporadic. Not at increased risk of second cancers.
Common presentation of RB • 50% - leukokoria • 20% - strabismus • Others – poor vision, red eye, glaucoma or orbital cellulitis On CT scan: solid mass within the globe with calcification (calcium)
Age of diagnosis • Average: 18 months – Bilateral: 12 months – Unilateral: 23 months – In 5% - first diagnosed after 5 years old.
Retinoblastoma and other Cancers • Trilateral retinoblastoma – Bilateral RB + midline brain tumours (pinealoblastoma) – Represents 3% of all retinoblastoma cases
• Second cancers associated with RB: (germline mutation) – Osteosarcoma (femur) – Cutaneous melanoma – Other sarcomas – Peak age is 13 years old
Options for management • • • • • • •
Enucleation Chemotherapy Thermotherapy Cryotherapy Laser photocoagulation Plaque radiotherapy External beam radiotherapy
Counselling Chances of Having a Baby with Retinoblastoma Parents
Affected child/Patient
Normal sibling
No Family history Bilateral RB Unilateral RB
6% 1%
40% 8%
1% 1%
Positive Family Hx Bilateral RB Unilateral RB
40% 40%
40% 40%
7% 7%
Congenital glaucoma
Congenital Glaucoma: Signs and symptoms
Epiphor a
Classi c triad Photophobi a
Blepharospas m
Cloudy cornea, Haabâ&#x20AC;&#x2122;s striae
Optic nerve cupping. May be reversible
Gonisoscopy: anterior iris insertion, indistinct trabecular meshwork
Buphthalmos (large corneal diameter >12mm) Long axial length
– Starts at 16 weeks of gestation – Reaches nasal ora at 36 weeks – Complete vascularisation at 40 weeks
Zone I Zone II Zone III
Nasal ora serrata
• A vasoproliferative retinal disease that affects premature infants • Normal retinal vasculogenesis
Temporal ora serrata
Retinopathy of Prematurity (ROP)
Retinopathy of Prematurity (ROP) Normal retinal vascular development is arrested by premature birth
Peripheral retinal ischaemia leads to release of VEGF
Retinal and extraretinal neovascular proliferation occurs
Advanced proliferative disease can bleed, cause traction, and lead to retinal detachment and blindness
Gestational age of < 30 weeks
Low BW less than 1500g
Risk factors of ROP Complicated clinical course
Prolonged supplemental oxygen
Classification of ROP
Nasal
ral o ra se rrata
â&#x20AC;˘ Based on location of disease in the retina and its severity
rrata
Tem po
ora se
Zone I
Zone II Zone III
ROP: Treatment • • • •
Observation for stage 1 Pan retinal photocoagulation Cryotherapy Intravitreal injection of anti-VEGF
Vernal Keratoconjunctivitis (VKC) • Frequently associated with atopy – asthma, hay fever, eczema • Recurrent, bilateral • Affecting children and young adults • More common in males and warm climates • Itching, mucoid discharge, tearing • O/e: Pigmented conjunctiva, papillae, PEE+, superior limbic keratoconjunctivitis, shield ulcer (deposition of eosinophilic granular proteins on corneal epithelium and trauma from intense eye rubbing) • Treatment: topical mast cell stabiliser, antihistamine, topical steroid, topical immunomodulator (eg cyclosporine) • May cause keratoconus
Capillary haemangioma/Strawberry naevus • Should be treated only if – Amblyopia caused by refractive error (induced myopia or astigmatism) – Ptosis causing visual obstruction or head tilt
• Treatment options – Corticosteroid injection or systemic therapy – Beta-blocker – Excision- in cases unresponsive to more conservative Rx – Interferon alpha-2 therapy
Congenital Nasolacrimal Duct Obstruction (NLD block) • At birth, the lower end of NLD is frequently non-canalised (valve of Hasner) • Usually canalises spontaneously soon after birth. 95% by 12 months old • Symptoms: tearing, matting of lashes • Management: – Conservative: NLD massage to increase hydrostatic pressure thus rupture the membranous obstruction – 10 strokes QID – Surgical: Probing to overcome obstructive membrane