DISTANCE ESOTROPIA

Question 1

What is distance SOT?

Answer 1

ET only at distance
* Careful investigation – quite rare and could be simulated by other conditions

Question 2

Characteristics of distance sot?

Answer 2

• Characteristics: Orthophoria or SOP at near with BSV, initially intermittent then more constant ET at distance, No sig refraction, Equal VA, BSV at near, Generally no dip at distance

Question 3

Differential diagnosis of distance esotropia?

Answer 3

Mechanical restriction – TED (Additional signs and symptoms e.g. lid lag etc.), Mild 6th CNP (OM – abduction limitation, age of onset), High myopia with abduction weakness (refraction), Convergence & accomm spasm (Variable PCT, > versions, VA reduced/variable) , Decompensating divergence weakness esophoria (Onset after childhood, diplopia), Divergence palsy (No (or little) –ve fusion)

Question 4

Investigation of Dis sot?

Answer 4

• Case history
• Refraction
• VA
• CT; light, accom target, dist, far dist, c & s gls
• BSV
• PCT
• OM - side gaze measurements + saccades
• Accommodation
• Convergence
• AC/A ratio

Question 5

What are aim of management in distance sot? (non surgical)

Answer 5

• Equal VA (Correct any refractive error, Correct any refractive error)
• Restore BSV at all distances (Can use prisms to maintain BSV whilst waiting for surgery)

Question 6

Surgery in distance sot?

Answer 6

• Treatment of choice – aim to slightly overcorrect
• Bilateral LR resections
• Asymmetrical LR resect / MR recess
• Unilateral LR resect / MR recess
  o Used if large near angle