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Clinical findings:

  • age of onset between 6 months and 4 years(usually at 18 months)

  • occasionally then one eye divergens patient close this eye in bright light

  • sometimes diplopia occurs

  • once suppression has been triggered by the eye drifting out

  • patients have a larger binocular peripheral visual field than normal people

  • typical cases have stereoacuity at near, this is where most patients control their deviation


  • assessment of vision, fusion and stereopsis

  • Hirschberg test at near and distance (Fig7,8)

  • cover-uncover test at near and distance

  • Maddox test

  • high AC/A can be diagnosed by the patch test

Differential diagnosis:

  • exophoria

  • congenital exotropia

  • convergens insufficiency

  • convergens paralysis

  • deprivation (sensory) exotropia

  • consecutive exotropia


  • correction of the refractive error especially myopia

  • myopic overcorrection shold be done only for eye- exercise

  • sometimes bifocals is a good solution

  • wearing the prism-glasses

  • the use of part-time occlusion

  • orthopic treatment

  • botulinum toxin A

  • strabismus surgery(bilateral recession)


  • cosmetic success is often defined as a deviation less than 15PD

  • functional success is than a deviation less than 10PD with peripheral fusion

  • some patients may miss the panoramic visual field inherent in intermittent exotropia
Convergence insufficiency

Convergence weakness is a type of exotropia in which the deviation is only or greater at near than at distance.Fig.9.10.

Fig.9 Convergens insufficiency. Small exotropia in the distance.

Fig.10 Convergens insufficiency when child looking at near point the exotropia appears.

Clinical findings:

  • asthenopic symptoms usually occurs during periods of near work

  • often diplopia occurs

  • rarely convergence near point is more remote than 20-25 cm

  • patients may induced an artificial myopia

  • typical cases have stereoacuity at distance, this is where most patients control their deviation

  • on repeated testing patients are easily fatigued

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