Congenital Uniocular Cataract Management Strategy

Denis Stark 07/03/01
 
 

Current Management Recommendations:

• Extraction of Cataract and correction of vision with a Contact Lens + a regime of Occlusion of the normal eye.
• Needs to be performed before 2 months of age if visual improvement is to be expected. (Appendix 1 Amblyopia )
• Surgery after that date of no benefit.

Effectivity of Current Therapy:

Even with this ideal management a very limited number of patients gain useful vision because

                    The difficulty involved in maintaining a contact lens and occlusion.

                    Aphakia (absence of ocular lens) is almost as powerful amblyogenic factor as the cataract.

If no surgery is performed - there is no chance of visual recovery.

Possible Management:

• Removal of Cataract and Insertion of an Intra Ocular Lens.
• This still ideally should be performed in first months of life.
• The strength of the lens should initially undercorrect the refractive error.
• Occlusion + a contact lens will still be necessary.

Advantages of this therapy:

1. A closer simulation of ‘normal refraction’
1. Some series - very small with limited followup support the benefit of this therapy. (Sinskey, O’Keefe, Lambert, Cheng,Vasavada)

Disadvantages of this therapy:

1. More complicated surgery - more potential complications
1. Still uncertain response.
1. It is still difficult to measure advantages.

Theoretical advantages:

• Possible chance of recovery of some vision because of better stimulation by better focus.
• Still reduced chance of recovery - dependent on age at time of surgery.
• Vision at the best is likely to be only poor to moderate.
• Possibly may have sufficient vision to prevent eye from drifting.

Theoretical disadvantages:

• Still very poor chance of visual recovery.
• Will require patching and probably a contact lens
• Complications of the Surgery:

1. The Worst: loss of the eye

1. The need for more operations unplanned at this stage

• Glaucoma
• retinal
• corneal

1. The need for more planned operations

• Exchange of IOL
• Addition of IOL
• Possible Clearing of visual pathway

With a very experienced Cataract Surgeon , in spite of the risks cataract extraction and simultaneous lens insertion probably gives an infant the best chance of obtaining the best visual result.
 
 
 
 

Appendix:

Amblyopia  (Click herefor more details regarding AMBLYOPIA)

The vision of an infant is still developing. Anything, which interferes with this development, can result in permanent failure of vision.

The factors which can be involved:

1 Poor focus - the need for corrective lens.

2.An opacity in the line of vision

3. Poor aim- a turned eye.

Congenital cataract results in an opacity in the line of vision.

If this cataract is removed the focus of the eye is then extremely poor.

- Unless a lens is placed in the system

Thus we have 2 factors adding to the effect of visual failure.

Time: The first months of life are critical. The failure to stimulate the visual brain in this period has a very severe effect on visual development making it ALMOST IMPOSSIBLE TO DEVELOP VISION LATER.