Constant Esotropia

• Constant esotropia


  A type of esotropia where the deviation is present under all conditions
• Non-paralytic esotropia


  • There are 4 main groups: Primary, Consecutive, Secondary (sensory), Residual
• Primary constant esotropia


  The esotropia is the initial defect and is present under all conditions
• Esotropia is more common than exotropia in childhood (Western populations)
• Prevalence of esotropia in school children: 0.3%-3.6%
• Risk factors for esotropia

  • Low birth weight <3kg
  • Premature birth before 37 gestational weeks
  • Large head circumference
  • Children with chromosomal abnormalities or syndromes
• Accommodative element in esotropia


  The esotropia is affected by accommodative effort. The size of the deviation is significantly reduced following correction of refractive error.
• Non-accommodative element in esotropia


  The esotropia is unaffected by accommodation and the size of the deviation is approximately the same with and without refractive correction.
• Causes of accommodative esotropia

  • Uncorrected refractive error
  • High AC/A ratio
• Constant esotropia with accommodative element


  The accommodative element may be refractive (uncorrected hypermetropia) or due to high AC/A ratio
• Constant esotropia without accommodative element


  Includes infantile ET, acquired non-accommodative ET, late-onset (normo-sensorial) ET, acquired ET with myopia, nystagmus block syndrome, micro-ET
• Acquired non-accommodative esotropia


  • Early onset (6 months - 2 years): Amblyopia common, poor prognosis for restoring BSV, deviation may increase with time, often require surgery
  • Late onset (2-8 years): May be caused by minor injury/short period of occlusion of 1 eye, onset may be intermittent causing constant & large deviation, good prognosis for restoring BSV
• Acquired esotropia with myopia


  • Moderate degree (-6 to -12DS): Gradual onset & present in young adults, ET > for distance
  • High degree (>-15DS): Very gradual onset, often 1st present in adult life, associated progressive myopia, rarely c/o diplopia, restricted OM limitation of abduction
• Micro-esotropia


  Small angle esotropia measuring <10BO, present with a reduced level of binocularity
• Secondary (sensory) esotropia


  Typically occurs due to visual loss or visual deprivation, anatomical or physiological cause
• Consecutive esotropia


  Initial deviation was an exotropia, typically related to an over-correction of exotropia surgery
• Residual esotropia


  An esotropia persists following surgical correction, often a smaller angle than the initial deviation