Spotting of disc haemorrhages on fundus pictures; on Kodachrome slides and on digitally enhanced images.

Purpose: To find out whether digital processing can facilitate interpretation of fundus photographs.

Methods: Digitised fundus pictures were manipulated and enhanced by a process called histogram equalisation. Essentially, the gamma values for red (R), green (G), and blue (B) were separately modified.

A computerised adaptometer.

Purpose: The design of an automatic instrument for the estimation of subjective dark adaptation (minimum perceptible for light) by an uninterrupted chain of trials.

Methods: A light emitting diode is used as test light. The patient answers by pressing a button when light is perceived.

An instrument for recording the ocular pulse wave.

An instrument for recording the ocular pressure pulse is described. Examples of recordings showing individual differences in the shape of the pulse curve are demonstrated. The properties of the instrument as to the frequency response in the range 0.

A model for pulsatile and steady ocular blood flow.

Background: The aim was to elucidate two controversial questions. (1) is the pulsatile inflow dominant or is there a sizeable steady inflow component? (2) Is the outflow of blood steady or pulsatile in induced and in glaucomatous hypertension?

Methods: The OBF system (Langham) was used for pulse recording. A simple electric flow model was conceived and analysed in terms of Fourier series, using linear circuit theory.

Disk hemorrhages and retinal vein occlusions in glaucoma.

There are several reasons to consider disk hemorrhages, branch retinal vein occlusions and central retinal vein occlusion as manifestations of the same vascular disease, the only difference among them being the size of the vessel affected. There is a close association of these vascular events with open angle glaucoma, and all of them increase with increasing follow-up time. The morphological changes described in the retinal veins in glaucoma and in central vein occlusions are endothelial proliferations causing progressive increase of flow resistance.