Consider that not so long ago, considerable concern was expressed among optometric educators that our focus on optics was diminishing with the increases in biologic sciences training related to eye disease management responsibilities. Many challenged the NBEO to reflect soberly on student performance in optics on the National Board examinations and some practitioners warned that there was a diminished interest in optics. However, it is now clear that the “new” optics has more, not less, relevance to the practice of optometry than it did just 10 years ago. As a result of new developments in measuring and correcting the aberrations of individual human eyes, two excellent and prophetic editorials in Optometry and Vision Science heralded these changes in optometric and ophthalmologic practice.1,2
Now the modern “new visual optics,” the ability to characterize, measure, correct, and even begin to relate the eyes’ optical aberrations to vision expectations in simple ways beyond the spherical and cylindrical “aberrations,” is now commonplace in refractive surgery, optical instrument design, and even contact lenses. It is also applied to wavefront-guided designs of spectacle lenses, intraocular lenses, and measuring the outcome of refractive therapies objectively by quantifying the optical quality of the eye with wavefront aberrometry. It will lead to improved diagnostic imaging of the fundus and other internal structures of the eye by correcting the patient’s own optical aberrations.
At least three schools and colleges of optometry have research and teaching programs that clearly intend to expand these applications. Continuing education courses related to this new visual optics are becoming more common across the country.
The new thrust in applying the very best of our optical knowledge has made heretofore relatively unknown terms and expressions now part of regular optometric conversation. We are even seeing the terms used to market new products. Terms such as “wavefront aberration measures,” “adaptive optics,” and “Zernicke coefficients and terms” are now all firmly entrenched in every optometry school curriculum and commonplace in continuing education courses around the world.
We have also seen our horizons expanded with at least two recent Academy symposia dedicated to optics of the eye and the potential to correct a range of previously “unmeasurable” or difficult aberrations. In fact, it is fair to say that optometric researchers have been at the forefront of the developments in wavefront and adaptive optics.
One of those prominent researchers, Ray Applegate, OD, PhD, FAAO, recently noted (by personal communication), “Optical defects that we used to throw into the waste basket of irregular astigmatism can now be easily quantified and often corrected in the clinical environment. The benefits of wavefront corrections are not limited to improving a patient’s vision. Wavefront corrections also improve the doctor’s view into the eye. And new single value metrics of retinal image quality are being developed to predict visual performance with correction of these aberrations. These gains in retinal image quality are particularly noticeable in low light environments where low contrast acuity is important. No longer do we have to be satisfied with providing highly aberrated eyes with good retinal function 20/25 to 20/30 vision in a marginally comfortable hard lens. Soon wavefront guided soft lenses capable of providing 20/15 vision will be routinely available for these highly aberrated eyes (e.g., keratoconics).”
The ability to measure and correct previously ignored aberrations of the human eye has raised very basic research questions about the potential vision “enhancement” an individual may get from the corrections and in what environments. An improvement in vision is intuitively obvious, but not a “slam dunk” in all situations, as our Prentice lecturer points out in this issue of OVS.
However, the promise of 3× resolution of our patient’s eye and retina is already demonstrated and will lead to new generations of ophthalmic instruments. The horizons for retinal and optic nerve head research have been greatly expanded because of this. And there can be little doubt that highly aberrated eyes, like keratoconic eyes, can expect to gain significant improvement as this field develops.
There are entire meetings and societies dedicated to advancing this field, and the recent 7th International Congress on “Wavefront Sensing and Ideal Refractive Corrections” in January 2006 revealed a strong optometric, ophthalmologic, basic researcher and industry contribution to research advances in the field.
In this June issue of OVS, there are a number of papers related to optics.
We lead with a superb presentation by the Academy’s 2005 Prentice Lecturer, who is arguably the “father of wavefront adaptive optics.” He marvels at the human eye as a remarkable optical instrument, well adapted to the neural design of the visual system, and traces the advances in the modern application of both the measures and correction of its optical aberrations.
Another article describes what might be the first custom eye models for personalized contact lenses, refractive surgery, and implants. Combining patient data with powerful optical design tools, an optical model is reported to reproduce, with high fidelity, the refractive state and optical quality of a particular eye for custom ophthalmic optics, contact lenses, intraocular lens implants, and refractive surgery.
Attention is also drawn to the limitations of certain aberrometer designs in assessing asymmetric aberrations, and four other papers report research involving more traditional optical imaging of optical components of the eye; one assesses “vision quality of life” after corneal refractive therapy.
If we were wondering whether optics of the eye had become just a boring essential of our training, there is good reason to stop wondering! The new visual optics and its implications for all kinds of clinical diagnostic imaging and new frontiers for correction of individual eyes have made it a “hot topic” for advances in eye and vision care. Optometry graduates of this new millennium are very aware of this.
Articles in this OVS issue remind all us of that fact.
Anthony J. Adams