PubMed Health⌕ Search

Biomedical subjects

Theodore Grosvenor

Publications and source records attributed to Theodore Grosvenor.

4 recordsLinked to original sources
PubMed2005

Twenty years of NZOVRF-supported scientific inquiry.

For many years, Alan Bott travelled from his optometric practice in Paeroa to supervise the contact lens laboratories and clinics at The University of Auckland. He was one of the founders of the New Zealand Optometric Vision Research Foundation (NZOVRF) working closely with Eugene Hirst and Dr Leon Garner (now Professor Emeritus Garner) to raise nearly $500,000 for the Foundation from 1985 to 1988. Alan passed away in 1999 as a result of prostate cancer. He is remembered fondly by all who knew him. Since its inception 20 years ago, the NZOVRF has supported research that has advanced our knowledge and understanding in many areas of optometry and vision science. Even a brief discussion of each of the 39 studies that the foundation has supported would result in a very long report, so I shall confine my remarks to an area that has been of great interest and controversy, especially concerning whether myopia and other refractive anomalies occur as a result of hereditary or environmental influences or both.

Biomedical Research↗
PubMedDate not supplied

Is there a hyperopic shift in myopic eyes during the presbyopic years?

BACKGROUND: Studies of age-related changes in myopia during the presbyopic years have produced contradictory results. Some studies have shown that myopic eyes undergo a hyperopic shift after the age of 40 or 45 years, whereas others have provided evidence for a myopic shift. In this paper, we report the results of both a cross-sectional study and a retrospective longitudinal study of age-related changes in refraction during the presbyopic years. METHODS: In the cross-sectional study, refractive error data were tabulated for the right eyes of 559 patients over the age of 45 years, who had been examined during a 17-month period in an established optometric practice. In the longitudinal study, we tabulated refractive error data on 100 myopes, 100 hyperopes and 100 emmetropes, who had been examined for periods varying from 10 to 26 years after age 40, all of whom had 6/6 visual acuity at all examinations. RESULTS: In the cross-sectional study, the prevalence of myopia during the later presbyopic years was found to be greater when eyes with all visual acuities were included than when only eyes with acuity of 6/6 or better were considered. In the longitudinal study, it was found that almost all hyperopic and emmetropic eyes showed an age-related hyperopic shift; but only a small proportion of myopic eyes shifted toward hyperopia, with others remaining relatively stable and still others increasing in myopia. DISCUSSION AND CONCLUSIONS: We suggest that when healthy myopic, hyperopic, or emmetropic eyes shift in the hyperopic direction, it is because of an age-related decrease in the gradient index of the lens; but when healthy myopic eyes shift in the myopic direction, it is because of axial elongation that more than compensates for the decrease in the gradient index of the lens. Another possible cause of a myopic shift, even for eyes having 6/6 visual acuity, is the presence of early, sub-clinical nuclear sclerosis.

Journal Article↗