I. Introduction: When attempting to remediate a strabismus in an infant or toddler, it is rendered very difficult due to the verbal and motor abilities of your young patient. Therapy at this time would have the most significant benefit, but it is next to impossible to communicate effectively with the young child. Sometimes, however, it is possible to construct a few very simple devices that can

1. Monitor suppression

2. Enhance binocularity

3. Reduce the likelihood of developing sensory anomalies (i.e. ARC)

II. The very young patient (< 1 year old): here, minimal occlusion times are adequate. It is best to use an adhesive patch (Opticlude, Junior sized)

A. Amblyope/high amblyopic risk (unilateral strabismus, eccentric fixation, etc.):

1. Direct occlusion (of sound eye) for a short period of time daily:

a. 1-2 hour direct occlusion/day usually does the trick

b. it is usually safe to patch for up to a 24 hour period, alternating with an off day

c. must stress importance of limiting time of occlusion (to avoid occlusion amblyopia)

2. Often, it is best to place the patch on the sleeping infant before he/she awakens for feeding. This is a fairly active time for the infant.

3. Amblyopia usually improves significantly without further therapy

a. non-strabismic amblyopes will respond better to visual activities (ocular motility, eye-hand coordination etc.)

b. strabismic amblyopes will have better fixation skills with the amblyopic eye

i. strabismus may become alternating instead of unilateral

ii. central fixation may be re-established

B. Strabismus (unilateral or alternating): very similar to above regimen. Constant occlusion is not viable at this point due to occlusion amblyopia concerns. Some authors report success, however, with constant occlusion alternated every 4 hours. I would expect compliance to this strict regimen would be very low. It is probably best to not use constant occlusion on infants with strabismus. Any occlusion for an intermittent strabismus should be guarded very carefully.

III. Occlusion and the Toddler (1-3 years old): here increasing occlusion times are permissible, but it should not be constant and should always accompany an active therapy regimen.

A. Amblyope/high amblyopic risk (unilateral strabismus, eccentric fixation, etc.):

1. Direct occlusion (of sound eye) for a longer period of time daily):

a. 1 hour direct occlusion/age of the child in years is a very safe rule to follow

b. occlusion times above this level (up to one day direct occlusion/age of the child in years) is almost always a safe bet, but should be monitored and NOT done if strabismus is intermittent

i. risk of occlusion amblyopia (lessened)

ii. risk of occlusion strabismus (if not a constant strabismic already)

2. Again, it is important to choose a time to occlude during a fairly active time for the toddler.

3. Amblyopia usually improves significantly in conjunction with active therapy (please review your amblyopia therapy notes for further details).

B. Strabismus (unilateral or alternating): Constant occlusion is a viable option at this point and should be considered in all cases of constant strabismus. Any occlusion (over 2-3 hours/day) for an intermittent strabismus should be guarded very carefully.

1. For constant strabismics, constant occlusion alternated at regular intervals is important to prevent amblyopia and inhibit ARC development.

a. alternating strabismics: alternate the patch on a daily basis

b. unilateral strabismics: after two days of occlusion, alternate the patch from the dominant eye to the non-dominant eye for one day, then repeat the cycle

2. For intermittent strabismus, occlusion is best limited to the amounts listed for amblyopia (to prevent occlusion strabismus)

3. For esotropes, binasal occlusion may be quite helpful in:

a. initiating a vergence response

b. preventing cross fixation patterns

IV. Preschoolers (3-5 years old): for amblyopes, minimal occlusion therapy in conjunction with monocular skills enhancing activities is quite successful. For constant strabismics, constant occlusion, alternated daily is your best bet to break down ARC or suppression.

V. Other Passive Modes Of Therapy For Young Children: Over-correction and Prism

A. Over-correction (or full correction, if high refractive error): May be necessary to clear optical image, enlist accommodative vergence to boost the binocular system or establish a centration point at farther from the nose.

1. Esotropia:

a. over-plus may establish intermittency

b. over-plus may bring the centration point away from the child's nose

c. full minus to a young esotrope is risky; monitor for increased magnitude or frequency of strabismus

d. addition (up to +4.00) possible by age 5

2. Exotropia:

a. full plus may be risky

-may increase frequency of strabismus

-many times, however, increased optical clarity actually reduces frequency of strabismus

b. over-minus may establish a pseudo-centration point for the child

-some vergence arising from accommodative convergence

- accommodative vergence as a "boost to the fusional vergence system

B. Prism application

1. Eso deviations:

a. relieving prism:

b. neutralizing prism:

c. overcorrecting prism:

d. prism adaptation:

2. Exo deviations:

a. relieving prism:

b. neutralizing prism:

c. overcorrecting prism:

d. prism adaptation:

VI. Active Modes Of Therapy For Young'ins:

A. Reminder : if a congenital or early acquired esotrope does not respond to passive modes of therapy, and is under the age of two, it is wise to suggest surgical alternatives with the parents. Remember, however, that you should set up a co-management system with the surgeon. You should offer post-operative care and continue with VT to improve visual function.

B. Active therapy for the infant:

1. Anaglyphic shapes and blocks on a black background: black, red and green blocks or pegs can be arranged on a dark background. The child will pay less attention to a black block on a black background (ie. monitor suppression by infants interest/lack of interest to toy)

C. Active therapy for the toddler/pre-schooler:

1. Anaglyphic beads and games (on black background): create patterns with red, green and black blocks/pegs on a dark background. See if child can match your pattern.

2. Binasal occlusion for full time wear: may establish motor divergence in esotropes

3. Basic Tranaglyphs: Fairy tales, Holiday series are good alternatives

4. Modified Doell mazes: use green pen to "stay in the lines" of the red maze. Have the child color inside the lines of the picture