purpose: to assess parameters that had a capability of influencing the rate of big bubble formation during deep anterior lamellar keratoplasty (dalk) in keratoconus. methods: a total of 290 consecutive eyes from 257 patients with keratoconus that underwent dalk using the big-bubble technique were enrolled. the influence of patient age and sex, family history of keratoconus, history of contact l...

An experimental study has been carried out to characterize bubble formation, growth, and detachment mechanisms in a stagnant liquid column. Both bubble frequency and bubble detachment size were measured in different gas flow rates, injector diameters and orientations, submergence height, and liquid properties. Experiments were performed for air injection flow rate ranges between 200 mlph and 12...

purpose: to determine the effect of retained donor descemet membranes (dms) on visual outcomes following deep anterior lamellar keratoplasty (dalk). methods: in this retrospective comparative study, keratoconic eyes undergoing dalk using the big-bubble technique were enrolled. a bared dm was achieved in all cases. a donor cornea without (group 1; 48 eyes) or with (group 2; 22 eyes) dm was sutur...

Gas holdup and bubble size are important parameters for simulation and designing in bubble column reactors. Because based on these parameters, the available gas-liquid interfacial area is defined for mass transfer. In this paper, the results of applying magnetic fields on the velocity field and volume fraction of gas holdup are reported. Hydrodynamics of the bubble column in the reactors is inv...

purpose: to report the possible transmission of zygomycetes infection by a corneal graft harvested from a donor with signs of trauma to the orbital region to a keratoconic patient who underwent deep anterior lamellar keratoplasty (dalk). case report: a 19-year-old keratoconic man underwent dalk in the right eye. the corneal graft was harvested from a donor with signs of orbital trauma. on posto...

Haptic force-feedback offers a valuable cue in exploration and manipulation of virtual environments. However, grounding of many commercial kinesthetic haptic devices limits the workspace accessible using a purely position-control scheme. The bubble technique has been recently presented as a method for expanding the user’s haptic workspace. The bubble technique is a hybrid position-rate control ...

purpose: to determine the dissection level during deep lamellar keratoplasty (dalk) using the big-bubble technique by light microscopy (lm) and transmission electron microscopy (tem). methods: descemet’s membrane (dm) and stromal tissue of 4 keratoconic eyes were removed because of inadvertent intraoperative dm perforation during dalk which was converted to penetrating keratoplasty. these speci...

purpose: to compare visual outcomes after deep anterior lamellar keratoplasty (dalk) between eyes with and without successful big-bubble formation. methods: in this retrospective comparative study, a total of 290 consecutive eyes from 257 keratoconus-affected patients underwent dalk with the big-bubble technique were enrolled. in cases where the big bubble could not be accomplished, manual stro...

This paper describes an experiment that was conducted to evaluate three interaction techniques aiming at interacting with large virtual environments using haptic devices with limited workspace: the Scaling technique, the Clutching technique, and the Bubble technique. Participants were asked to paint a virtual model as fast and as precisely as possible inside a CAVE, using a “desktop” haptic dev...