VT Works

The first time I encountered Dr. Harry Wachs was in 2005, not long before his 81st birthday. He and his wife Ruth, had traveled to San Diego for Dr. Wachs to impart his incredible knowledge and vast experience on the thrity five of us lucky enough to call ourselves his seminar audience. That particular seminar was conducted over three separate weekends, spread out over a summer, and lured some of the great doctors of our time to participate. “Harry”, as he insisted we refer to him, opened doors through his teaching whose existence may not even have occurred to us before meeting him. The lessons learned from that seminar still resonate loudly in the years since Harry’s passing.

One of the gifts Harry left us (there were literally hundreds) is an activity named Wachs Mental Minus. The activity fits within the hierarchy of monocular accommodative sequencing, concludes with a bi-ocular challenge, and asks the patient to build and maintain both awareness and regulation of their accommodative system as progress is achieved through the levels. Over the next week or so, I will offer my interpretation of the do’s and don’t’s of each level.

Level One – Tromboning

The goals of this level are multi-faceted. Along with changes in accommodation, patients may report SILO awareness, accurate or inaccurate spatial localization, awareness of their eyes changing, the speed or rate of change, and the possible need to increase or decrease their distance from the target.

Assuming our patients are sitting comfortably and in good posture, level one is completed with a patch on one eye. There may be times when choosing which eye to start with is significant (refractive amblyopia, etc), and other times where which eye goes first is less important. This is definitely something each Vision Therapist should discuss and decide with their Developmental Optometrist ahead of time as they prepare for the session beforehand.

Through trial and error, I have found that this level of Mental Minus is a bit counter-intuitive, esentially asking us to work backwards. Typically, with accommodative activities, the name of the game is to start small and work our way up in power, but that is not the case with level one. Rather, it’s best to start with a higher power and work our way down.

In most cases, we will begin with a -6.00 lens and a target with an age appropriate font size. The key factor is to choose a lens which causes the patient to exert reasonable effort to accomplish relative clarity. This aspect can also require the Vision Therapist to adjust the initial lens power based on the patient’s age, refractive status, and level of correction.

With the patient maintaining Harmon’s Distance, they are asked to place the lens in front of the open (non-patched) eye. The first step is to ensure the patient can clear the power of lens we have chosen, and if not, this is our opportunity to adjust, either by offering a stronger or weaker lens, until we find the lens power the patient is able to clear with some effort. Again, this is something each Vision Therapist should discuss and decide with their Developmental Optometrist prior to beginning this activity. Once the “ideal” lens is chosen, the lens can slowly be moved closer and farther from the eye while the patient maintains clarity. Remember, moving the lens away from the eye decreases the accommodative demand, while moving the lens closer to the eye increases the accommodative demand. At its closest, the lens should be flush against the patient’s face, and at its farthest, the lens should be no closer than a few inches from the target.

Subjective evaluations the Vision Therapist might watch for are:

Pupil restriction with an increase/decrease in Accommodation – the closer the lens is to the eyeball, the higher the accommodative demand the more pupilary constriction that can be observed.

Convergence or divergence of the eye under the patch as the lens is moved closer and farther from the open eye. Remember, vergence and accommodation travel together, so the more accommodative demand, the higher the rate of convergence and the lower accommodative demand, the higher the divergence.

Strenghth and balance of change is also important. As the patient trombones the lens, are they able to make the accommodative changes needed so the target remains clear at all times, or does the clarity “swim”, meaning it varies between blurry and clear as the patient completes the activity. Does the “swimming” occur when the lens is moving or also when the lens is held still?

Does the patient feel their eyes changing? Do they have that level of awareness? Can they use the information learned to recreate the accommodative posture?

What is their current level of awareness with respect to the changes in spatial awareness? Can they appreciate these changes? Are they able to localize – that is create a connection between the feeling inside their eyes and the current level of accommodative demand? Do they report any SILO awareness?

When the patch is moved and the activity is repeated with the other eye open, is there a difference in ability, feeling, or performance? Does the patient note their eyes hurt or are residually uncomfortable?

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As mentioned above, the overall goal of this activity is to build patient awareness of many aspects of the accommodative system, including feeling tone and localization, to name a few. In terms of Skeffington’s Circles, this activity might be considered part of the “What Is It?” or Identification Circle; however, it is important to remember that when it comes to the visual system, no skill exists in a bubble. Other areas to consider are the “Where Am I?” and the “Where Is It?” questions as a reasonable understanding of both are included in the list of skills necessary to achieve accurate and efficient accommodation.

Stay tuned for level two!