Near esotropia

Question 1

What is near SOT and aetiology?

Answer 1

• Near (nonaccommodative convergence excess), ET only at near
• Aetiology: Due to high tonic convergence , No way of measuring tonic conv in humans – exclusion of high AC/A ratio

Question 2

Characteristics of near sot?

Answer 2

• Age of Onset 2-3yrs
• Characteristics: Orthophoria or E at distance with BSV, ET at near, No sig refraction, Equal VA, Normal AC/A, Normal accomm, BSV at near when ET neutralised, No change to ET with +

Question 3

Investigation of near sot?

Answer 3

• Case history
• Refraction
• VA
• CT; light, accom target, dist, c & s gls
• BSV
• PCT
• OM
• Near point of accommodation
• AC/A ratio

Question 4

What are aims of management in near sot?

Answer 4

• Equal VA (Correct any refractive error, treat any amblyopia)
• Restore BSV at all distances (Can use prisms to maintain BSV whilst waiting for surgery)
• Achieve good N & D CBA

Question 5

Surgery in near sot?

Answer 5

Treatment of choice
* Bilateral MR recession +/- loop sutures
* Post-op – may need to strengthen BSV
o Prisms
o Orthoptic exercises