paediatric

• Paediatric Ophthalmology


  An Introduction
• Annette Parkinson
• Embryology


  A general understanding of the embryology of the eye is useful to understand congenital ocular disease
• EMBRYO


  Embryology of the Eye
• Development of the Eye

  1. The optic vesicle grows out from the primitive forebrain

  2. The vesicle begins to invaginate to form the optic cup. The surface ectoderm thickens to form the lens placode. (27 days gestation)

  3. Further invagination allows the lens vesicle to form and separate from the surface ectoderm which will form the corneal epithelium

  4. 41 day embryo
• Inheritance patterns


  • Dominant
  • Recessive
  • X-Linked
  • Mitochondrial
• Genetic Disease


  • Autosomal – carried by chromosome other than the sex chromosome
  • Diseases may vary in severity due to the degree of "expression" of the genetic factor
  • An individual may carry the genetic marker but not demonstrate the disease due to lack of "penetrance"
• Autosomal Dominant


  Only one defective gene is required for expression of the disease
• Autosomal Recessive


  • Two faulty genes are required for diseases with this pattern of inheritance to be expressed
  • Diseases of this type are more common where consanguinity occurs
• 1. linked Recessive


  • Predominantly affects males
  • Requires both parents to carry the affected X chromosome for females to be at risk
• 1. linked Recessive


  • Albinism
  • Colour deficiency
  • Retinitis Pigmentosa
• 1. linked Dominant


  • Affected mothers
  • Sons and Daughters manifest the disease
  • 50% normal
  • 50% affected
  • Affected Fathers
  • Daughters affected
  • Sons normal
  • Rarely seen in Ophthalmology – some forms of Retinitis Pigmentosa
  • Males more severely affected – often lethal
• 1. Linked inheritance - Holandric


  • The Y chromosome contains less genetic material than the X
  • Only one copy of the genetic material will be present
  • Diseases passed on through this pattern
  • Affect only males
  • All male children in the affected family will have the disease
  • Daughters of affected males are not affected
• 1. linked


  • Retinitis Pigmentosa
• Mitochondrial Inheritance


  • Transmission occurs via genetic material found in mitochondria
  • All children of an affected mother have the disease
  • Sperm cells carry no mitochondrial information - no children of an affected father have the disease
  • Appears to mimic dominant inheritance
  • Primarily leads to diseases associated with faulty enzymes
• Mitochondrial Inheritance


  • Leber's Hereditary Optic Atrophy
• In England in 2015 26 000 children and young people (0-25yrs) were registered as either severely sight or sight impaired
• Approximately 50% of these individuals will have additional special educational needs
• In Bradford 175 children (<18) are registered as either severely sight or sight impaired
• Not all visual impairment will be of sufficient magnitude to warrant registration
• A significant proportion of visually impaired children will have an additional disability
• Additional disabilities


  • Hearing impairment
  • Physical disability
  • Learning disability
• You are 10x more likely to have vision impairment if you have a learning disability
• Severely sight impaired


  • Previously known as Blind registration
  • VA of less than 3/60 with a full visual field
  • VA of between 3/60 and 6/60 with a moderate reduction in the visual field e.g. Tunnel vision
  • VA of 6/60 and above with a very reduced field of vision especially if the lower part of the visual field is affected
• Sight impaired


  • Previously known as Partially sighted registration
  • VA of 3/60 – 6/60 with full visual field
  • VA of up to 6/24 with moderate field loss or central vision cloudy or blurred
  • VA of up to 6/18 with a large part of the visual field missing e.g. Hemianopia or Tunnel vision
• Orbit - Craniosynostosis


  • Abnormalities secondary to abnormal skull development and growth
  • Premature fusion of cranial sutures
  • Crouzon's syndrome
  • Apert's syndrome (most severe form)
• Orbit - Craniosystosis


  • Orbits are abnormally separated
  • Wide PD
  • Up to 80mm
  • V pattern exo
  • High refractive errors
  • Amblyopia
• The Eyelids


  1. Develop from folds of surface ectoderm

  2. Lid margins fuse at 3/12 gestation

  3. Separation commences at 5/12 and is complete by 7/12

  4. The conjunctival sac forms behind the fused lids and in front of the embryonic cornea

  5. The levator muscle develops along with the other ocular muscles
• Microphthalmos


  • Early arrest of optic vesicle budding
  • Globe < 19mm in length at 12 months old
• Lid disorders - Coloboma


  • Developmental defect
  • Upper or lower lid may be involved
  • Treacher Collins syndrome
  • May be associated with cranial cleft defects
  • Cleft lip and palate
  • Require plastic surgery
• Lid disorders - Ptosis


  • 50% are due to levator dysplasia
  • The levator muscle is the last of the ocular muscles to form
• Lid disorders - Blepharophimosis syndrome


  • Ptosis
  • Telecanthus – wide separation of medial canthus
  • Short horizontal palpebral aperture
• Lid disorders - Epiblepharon


  Fold of skin rides up pushing the lashes onto the cornea
• Epiphora in the newborn


  • Delayed opening of the Valve of Hasner
  • Dacryocystitis
  • Lacrimal sac infection
  • Stagnant lacrimal sac contents become infected
• Spontaneous resolution of epiphora in the newborn may occur
• Syringing is only considered after 6 – 8 months of age for epiphora in the newborn
• PHAKOMATOSES – "BIRTHMARK"


  • Sturge-Weber – Port Wine Stain
  • Neurofibromatosis (Von Recklinghausen's Disease)
• Capillary Hemangioma


  • Most common benign peri-ocular tumour in children
  • Appear age 1-2 weeks
  • Increase rapidly to age 6 or 12 months
  • 75% resolve by age 5
  • Risk of amblyopia, squint, astigmatism
  • Treatment - Steroid injections
  • Most common benign orbital tumour in adults is the Cavernous hemangioma
• Naevus Flammeus


  • "Port Wine Stain" – present at birth
  • Capillaries are permanently dilated
  • Grows throughout life – no regression
  • More common in girls (0.3% incidence)
  • Follows distribution of the Trigeminal Nerve
  • Risk factor for glaucoma
  • Trigeminal - Ophthalmic division involvement – high risk
  • Maxillary and Mandibular divisions only - low risk
• Naevus Flammeus


  • 30% develop glaucoma on affected side
  • Early onset (< 2 yrs) abnormal angle
  • Late onset (>4 yrs) raised episcleral pressure
  • Choroidal hemangiomas may also occur
  • Retinal detachment