The band Street Joy has a tune, PLASTIC VISION, the lyrics of which contain this telling line: But what you don’t know is that you don’t know. Plastic vision seems like a cumbersome phrase, partly because of its passivity, as opposed to visual plasticity – comparatively more vibrant in its implied activity. Yet Plastic Vision was the name that the Centre of Vision Research at York University in Ontario, Canada attached to a Conference it held in 2011 to review the latest findings on visual and multimodal plasticity. Visual plasticity is what we developmental optometrists have been hanging our shingles on for years, and when children were rushed into early eye muscle surgery, or parents were told that it was too late for their child to gain any benefit from vision therapy, we persisted and helped patients anyway. In my textbook originally published in 1997 I wrote that visual plasticity remains in the visual system through adulthood, and that no one should be denied the opportunity based on age considerations.
Researchers at that time didn’t know what they didn’t know. That is changing due, in part, to the work of optometric researchers like Dennis Levi and his colleagues, and the cachet of individuals like Sue Barry who are influencing researchers to question ophthalmic dogma in the face of successful clinical outcomes. There should be attribution of these “new” concepts to principles we’ve been employing in optometric vision therapy for years. Looks instead like we’ll have to settle for Schopenhauer’s stages of truth, identified almost 200 years ago as: ”Wahrheit ist allerzeit nur ein kurzes Siegesfest beschieden, zwischen den beiden langen ZeitrÄaumen, wo sie als Paradox verdammt und als Trivial gering geschÄatzt wird.” Translated as: To truth only a brief celebration of victory is allowed between the two long periods during which it is condemned as paradoxical, or disparaged as trivial.
It therefore with great interest that I took note of the Conference on Plastic Vision at York University in 2011. In addition to her invitation to present her experiences with optometric vision therapy, Sue Barry was joined at the conference by, among others, Robert Hess. Hess published his work on looking at amblyopia as a problem in binocular vision rather than strictly as a one eye problem in Optometry and Vision Science in 2011. You can see an updated version of the work by Hess here, and a spinoff article in IOVS. I’ve learned a tremendous amount about amblyopia by reading Hess through the years. He has enjoyed a distinguished career in vision science as you can see by the litany of his publications. Although the long-term outcome of his first go at an amblyopia therapy device, the CAM Vision Stimulator, co-developed with Campbell, Watson and Banks, was disappointing, that device served as the basis for a broader understanding of what drives amblyopia therapy, the holy grail of which was held to be virtual reality games captivating enough to engage children’s attention for sustained periods of time such as the I-BiT or Interactive Binocular Treatment system. Interactive virtual reality systems will be the step beyond excellent therapy systems such as AmbP iNet.
Hence my double pleasure in seeing the topics covered by Sue Barry and Robert Hess now published in book form, with a more descriptive title than Plastic Vision. It is called Plasticity in Sensory Systems, published by Cambridge. As you may have guessed, I’ve ordered my copy online today, and am anxiously awaiting receiving it. As works of this nature enjoy broader distribution, they may influence the future direction collaborative research efforts between Optometry and Ophthalmology, such as the PEDIG studies. PEDIG has thus far been understandably conservative in their approach to broadening the understanding of plasticity in amblyopia therapy. The only binocular aspect of the PEDIG studies to date has been the passive MFBF approach afforded by pharmacologic penalization. Atropine penalization has deceptively elegant attributes of binocular integration, largely by manipulating accommodative balance between the two eyes without occlusion, but we can do better. As with the CITT, important strides are being made in the direction of what can be accomplished through optometric vision therapy. Slowly but surely, step by step ….