Keith Robertson

Learn More
The variations in fixation disparity (FD) with spatial frequency and retinal locus of fusion locks were examined in two groups of subjects having either steep or flat forced-duction FD curves. FD for subjects with flat curves was unaffected by either spatial frequency or diameter of fusion locks. FD of observers with steep forced-duction curves increased(More)
The initial velocity of the vergence response to step changes in disparity was examined in two subjects as a function of the retinal locus and spatial frequency of fusion stimuli. Vergence velocity decreased for both subjects as retinal eccentricity increased and it was unaffected by spatial frequency. The same subjects had very different amounts of(More)
Drug resistance is a major cause of failure in cancer chemotherapy. Therefore, identification and combined use of adjuvant compounds that can overcome drug resistance may improve the efficacy of cancer therapy. We screened extracts of Verticillium species-infected mushrooms for antitumor compounds and identified the compound Verticillin A as an inducer of(More)
Visual training has an effect on the vertical vergence amplitudes. Three mature symptomatic patients exhibited a significant increase in the vertical vergence which compensates for the vertical heterophoria. Subjects with normal binocularity and hence no vertical heterophoria did not exhibit increased vertical vergence amplitudes after training.
Our lift lip technique consists of an excision of the white part of the upper lip directly beneath the nose in the shape of a 'bull's-horn', with advancement of the inferior border of the incision to the area directly beneath the nose. Pre-operative markings on the skin ensure the lip lift is approximately symmetric. Advancement of the inferior edge of skin(More)
In some cases where a medium-voltage (MV) motor is to be used in an adjustable-speed application, the system design, equipment availability, or other factors might favor supplying the motor from a low-voltage system by way of a step-up transformer. While simple in concept, the use of a transformer to step up the drive output voltage to MV level is not a(More)
A series of compounds based on the structure of bacilysin were synthesised and tested for antibacterial activity. The key steps in the syntheses are the coupling of an iodide to a diketopiperazine (DKP) and mono-lactim ether scaffold, respectively. The diastereoselectivity of the coupling reactions was dependant on the scaffold, with selectivity for DKP of(More)
A 36-year-old male had been constantly wearing a patch to avoid diplopia since an operation on the right parietal area of the brain. Postsurgical visual field evaluation indicated a complete bilateral left hemianopia with macular splitting. The patient had a constant alternating comitant exotropia with no suppression. By terminating the patching,(More)
Steady-state and transient Visually Evoked Responses (VERs) were used to verify a paradoxical aniseikonic condition in an anisometropic patient. Testing on the Remole multimeridional horopter apparatus indicated that a 2% overall magnification was required for the more hyperopic eye to eliminate ocular image size differences. A special lens correction for(More)
  • 1