Dr. Irving maintains an interest in refractive error and ocular component development. Other areas of interest include: the developmental interactions between the ocular components; the relationships between intraocular pressure and ocular component development; the relationships between accommodation, convergence, image quality and refractive development; the effects of spatial filtering on refractive error development.
The ocular development research is conducted on chicks. This work is being done in collaboration with Dr. J.G. Sivak.
Chickens have become a common model for studying the effects of visual input on ocular development. Defocusing lenses are applied unilaterally to the eyes of newly hatched chicks in the form of a light-weight translucent plastic goggle. Since the goggle does not contact the eye, there are no mechanical interactions between the goggle and the eye. The following effects of wearing the goggle are examined: refractive error, corneal curvature, ocular dimensions, and intraocular pressure (IOP).
This work will provide information regarding the effect of visual information on the development of the eye (emmetropization) during early development. It may eventually be applied to human ocular development and in this way provide information on how to prevent the development of refractive errors during early childhood.
We have recently begun using Ultrasound Biomicroscopy (UBM) imaging techniques to determine the effects of induced ametropia on the anterior segment of the eye.
UBM is an ocular imaging technique which employs high frequency (50-100 MHz) ultrasound. Living tissue can be observed in vivo using this technique. The anterior segment of the eye can be viewed clearly and in more detail than was previously possible.
Image of the human eye's anterior segment showing cornea, iris, lens, ciliary body, and zonules. Although a view of the entire eye from cornea to retina cannot be captured at once, the UBM's image resolution is much greater than that of an A-B scan.
UBM image showing cornea, iris, ciliary body, and lens of a chick.