We, the editors, hope this special issue of OPO will serve as a reminder to many, of our precious friend and colleague, Josh Wallman, who lost his battle with pancreatic cancer in March 2012. We here pay tribute to Josh, a giant in the field of myopia research. Josh was a neurobiologist by training, with an extraordinary breadth of knowledge in all of science. A New Yorker through and through, Josh served on the faculty at City College of City University of New York (CUNY) for nearly 40 years, after completing his college education at Harvard University and a PhD at Tuft's University, both in Boston. His research laboratory and the many undergraduate and graduate students, postdoctoral fellows and research colleagues, were central to his life until the very end. To some junior researchers, it may come as a surprise that Josh was not always a myopia researcher. Eye movements and their control were the focus of his early research, which serendipitously led to his involvement in the field of myopia. An experimental paradigm intended to simply preclude vision in one eye of young chicks proved to result in extreme eye enlargement and myopia! Chicks proved not to be unique in this respect, as Wiesel and Raviola were to discover with their lid-sutured monkeys around the same time.
While Josh retained his interest in eye movements, this issue celebrates his enormous contribution to the myopia research field – through his infectious curiosity about how eyes grow, his willingness to be challenged and to challenge, his lack of regard for boundaries between basic and clinical research, his unstoppable energy and ultimately, through his lab's research. The overwhelming response to our call for papers, as well as contributions to the ‘Point counterpoint’ feature, attest to the high regard in which Josh was held internationally. Eight countries are represented among the contributors.
Here are the ways in which we have tried to capture the spirit of Josh.
First, we have included a review paper. There are few who will not have read the Winawer and Wallman review published in Neuron in 2004, entitled ‘Homeostasis of eye growth and the question of myopia’. We hope that the topic chosen for our review paper, ‘The Role of Chromatic Cues in Emmetropization’ will attract as much attention! While the question of how the eye decodes the direction of defocus remains largely unresolved, research undertaken in Josh's lab provided clues as to how chromatic aberration might be used. The review is written by Frances Rucker, Josh's close colleague and collaborator in this area.
Second, we are pleased to showcase the breadth of on-going research in the myopia field, a product of sending out a general call for original research papers. These papers span the full spectrum of myopia research, some animal-based, others human-based, and present data of all types – biometric, pharmacological, psychophysical, epidemiological and genetic. Four papers present animal-based research either inspired by work in the Wallman laboratory or collaboratively linked; three of these involve the chick model. The question of whether the magnitude of defocus affects the rate of eye growth compensation, initially addressed in a widely cited ARVO abstract from the Wallman lab (1997), is now found in paper form authored by Hammond, Wallman and Wildsoet. A second study with Josh as a co-author was undertaken in collaboration with Debora Nickla, and provides a new perspective on the ocular tissue sites of action of muscarinic drugs. A third study from the McFadden lab makes use of a protocol originating in the Wallman lab, to investigate the defocus-induced temporal response characteristics in guinea pigs. The results of all three studies have translational potential, such as in the design of novel contact lenses, drug dosing regimens, or behavioral interventions. The final paper in this group is an example of reverse translation, the application of a clinical technique, the mfERG, to the chick model. Just as application of this tool to human ocular disease has provided valuable new insights, it can potentially provide new insights into local retinal mechanisms contributing to altered ocular growth responses in animal models, and more.
We are excited to showcase among 10 studies involving human subjects, two studies dealing with optical control of myopia. One from Allen et al. reports on a randomized clinical trial of a dual focus contact lens treatment; the other by Kang et al. reports on the time course of changes in peripheral refractions and corneal topography induced by corneal reshaping therapy, which is being increasingly used for myopia control despite many unanswered questions in relation to both underlying mechanisms and target population. Another paper in this set concerns anatomical changes associated with myopia; specifically, Buckhurst et al. seek biometric correlates with ciliary muscle thickness. Four more papers have related themes, with investigations of blur adaptation in myopes versus emmetropes (Mallen et al.), nearwork-induced transient myopia in anisometropes (Liang et al.), the relationship between patterns of various activities and myopia development in children (French et al.), and the relationship between international educational performance and myopia (Morgan et al.). All of these papers present new perspectives or include novel twists on recurrent themes. Perhaps the best example of this is the use of anisometropia to control for intersubject variability in studying the influence of the amount of myopia on nearwork-induced transient myopia. The remaining two papers in this series deal indirectly or directly with genetic contributions to myopia. While the contribution of environmental factors to the development of myopia is no longer debated, neither is it debated that genes may play a role in determining susceptibility. One of these two studies investigated the age of onset of myopia in a British population-based twin cohort (Williams et al.); the other reports on a novel missense mutation in the NYX gene associated with high myopia (Yip et al.).
Finally, we are excited to present a series of six Point–Counterpoint articles addressing important unresolved questions in the form of written debates. Our players in the field were challenged to defend their nominated territory, by way of bringing out key issues, which we have summarized for you at the end of each set. We hope that you enjoy reading them as much as we enjoyed helping to put them together. Were not this issue put together in Josh's memory, we would most certainly have allocated a topic to him, although which one is a moot point, because he found scientific debate irresistible, irrespective of the topic!
In finishing, we hope that we have captured some of the energy and enthusiasm that epitomized Josh's myopia research and indeed, his life. His legacy will continue over the years to come, as his findings and ideas continue to unfold through on-going and future research. The hope is to find the means to control myopia, and to curb the current worldwide epidemic. We hope that you will agree that our choice of cover picture captures the very essence of Josh Wallman – a man of myriad interests and passions.