PubMed Health⌕ Search

Biomedical subjects

I Pieper

Publications and source records attributed to I Pieper.

3 recordsLinked to original sources
PubMed1981

Iris angiography and aqueous photofluorometry in normal subjects.

Iris angiography and photofluorometry of the aqueous were performed on 44 normal subjects equally distributed between 15 and 65 years of age. Hemoglobin AIc determinations were performed in 20 of these persons. Leakage from the pupillary margin was present in 20% of the eyes studied. In all cases of leakage, the dye faded quickly after the initial peak concentration. No leakage was observed from radial iris vessels. Photofluorometric readings of the aqueous 60 minutes after injection increased significantly with age. Hemoglobin AIc measurements were observed to correlate significantly with aqueous fluorescein concentration. Both these observations may reflect an altered permeability of biologic membranes associated with aging.

Adolescent↗
PubMed1980

Photogrammetry experiments with a model eye.

Digital photogrammetry was performed on stereophotographs of the optic nerve head of a modified Zeiss model eye in which optic cups of varying depths could be simulated. Experiments were undertaken to determine the impact of both photographic and ocular variables on the photogrammetric measurements of cup depth. The photogrammetric procedure tolerates refocusing, repositioning, and realignment as well as small variations in the geometric position of the camera. Progressive underestimation of cup depth was observed with increasing myopia, while progressive overestimation was noted with increasing hyperopia. High cylindrical errors at axis 90 degrees led to significant errors in cup depth estimates, while high cylindrical errors at axis 180 degrees did not materially affect the accuracy of the analysis. Finally, cup depths were seriously underestimated when the pupil diameter was less than 5.0 mm.

Astigmatism↗