Dean Jay Enoch (Emeritus)

School of Optometry

In Professor Enoch's laboratory, recent research has concentrated upon adult myopia and associated retinal degenerative phenomena. Myopia is a major cause of blindness and its prevalence has increased sharply worldwide, particularly in the Far East and Southeast Asia, where it affects the majority of teenagers. A substantial proportion of affected individuals usually have rather marked degrees of high myopia. Dr. Enoch has been studying the effects of myopia-related retinal traction that shift both retinal and choroidal tissue temporal-ward. In individuals with -5.00 D myopia or more, the retina and choroid literally override the nasal side of the optic nerve head or disc, and these over-rides can cover up to 2/3 of the optic disc. Such research has shown these displaced tissues to retain visual function (although reduced) upon the blind spot, and there is clear evidence for transient functional changes occurring in these tissues within short timespans. It is not known if these overrides represent a form of safety valve or whether they are a sign that the eyes will be subject to more serious degenerative changes in future years.

Myopic traction-induced changes are known by a variety of names, many dating from the mid-19th and early 20th centuries. Modern terms include myopic nasal super-traction of the disc and myopic super-involute (radial traction) of the disc. These disorders are often accompanied by twisted optic nerve heads or discs, thinning of the white sclera, etc; they can be detected and studied in detail by using modern OCT (Optical Coherence Tomography) techniques.

Research from Dr. Enoch's laboratory also investigates visual functions that have not been affected by aging, in order to understand why these functions are exempt from the common sensory losses found among the elderly. Can these functions be adapted to help in a positive manner to serve the aged? For example, one of the now known age-resistant visual functions is vernier acuity. Vernier acuity measurements are commonly employed when reading micrometers or height gauges, or other fine measuring devices. Because this function is not affected by aging, this same skill can also be utilized when filling a syringe for injections of insulin or other medicinal agents. Vernier acuity is also used to assess the quality of vision through dense visual opacities of the cornea, eye lens, etc., in order to aid the physician in judging the visual potential of a patient prior to surgery and to predict the outcome of his/her vision post-surgery. The latter application is of particular value in the developing world, where about 95% of patients are treated in only one eye due to limited health care provision and resources.

That the rapidly increasing blind and low-vision populations are largely comprised of the elderly underlies the need to develop an infrastructure for ocular examinations, corrections, and rehabilitation services by optometrists and low-vision providers in the developing world. These professional groups can supplement the limited numbers of medical practitioners available for such services, particularly in rural settings. Dr. Enoch has been active in the development of optometry colleges in India to help meet this need -- there are now 6 -- and he has sought to create a cadre of low-vision providers to help meet these incredible challenges.