Vergence Binocular vision problems

Question 1

What are the symptoms you would expect in somone who has a convergence insufficiency?

Answer 1

· These symptoms are generally related to the use of the eyes for reading or other near tasks:

o Eyestrain

o Headaches

o Blurred vision

o Diplopia

o Sleepiness

o Difficulty concentrating on reading material

o Loss of comprehension over time

o A pulling sensation around the eyes

o Movement of the print

Question 2

What are the signs of convergence insufficiency?

Answer 2

· Reduced NPC

· Greater exophoria at near than at distance

· Low AC/A ratio

· Reduced smooth vergence

· Reduced step vergence

· Reduced vergence facility

· Low NRA

· Difficulty with plus lenses during accommodative facility testing

· Low finding with MEM retinoscopy

Question 3

What are some underlying conditions which can mask convergence insufficiency?

Answer 3

Convergence paralysis secondary to:
· Ischaemic infarction 
· Demyelination 
· Flu or other viral infection 
· Parkinson disease 
· Parinaud syndrome 

Medial rectus weakness due to:
· Multiple sclerosis
· Myasthenia gravis
· Previous strabismus surgery

Question 4

What is the management for convergence insufficiency? and what is the prognosis?

Answer 4

In office Vision therapy (4 weeks):

• 60 minutes once weekly
• Gross vergence, brock string and barrel card
• Fusional Vergence, variable tranaglyophs and vetograms and lifesaver cards.

Home Vision therapy (15 minutes 5 times per week)

• brock string
• loose lens accommodative rock
• barrel cards
• lifesaver cards

the above is stage 1

Stage 2 is below: