Abstract We generate a spatiotemporal optical vortex (STOV) with tunable orbital angular momentum (OAM) orientation by simple lens system. utilize cylindrical system, which is an astigmatic mode converter, to add longitudinal tilt the purely transverse OAM in arbitrary direction. The amount of adjusting and thus direction continuously adjustable. STOVs adjustable directions have been verified t...

background: astigmatism is the leading complication in visual recovery after penetrating keratoplasty (pkp) and deep anterior lamellar keratoplasty (dalk); in this study, we evaluated the outcome of femtosecond laser arcuate keratotomy (flak) after dalk and pkp in iranian keratoconic patients. materials and methods: in this prospective interventional case series, refractive and keratometric pre...

A specially designed high resolution converging collimator having a focal length of 50 cm has been evaluated for cone beam single photon emission computed tomography (SPECT). The focal region was investigated by imaging a point source placed at the expected focal point and along the central ray of the collimator in front of and behind the focal point. Technetium-99m point source sensitivities m...

PURPOSE To evaluate agreement in measurements of astigmatic axis power and location between keratometry and computer assisted videokeratography (corneal topography) on normal corneas with less than 1.50 D of idiopathic astigmatism. METHODS Keratometric readings with the 10 SL/O Zeiss ophthalmometer and corneal topographic maps with the TMS-1 were obtained by two independent examiners on 32 no...

BACKGROUND To evaluate the torsional and flattening effect of steep meridian incisions and influence of posterior corneal astigmatism (PCA) on total corneal astigmatism (TCA) after cataract surgery. METHODS One hundred thirty-two eyes underwent cataract surgery with steep meridian 2.2 mm microcoaxial and 2.85 mm conventional clear corneal incisions. Eyes were divided into with-the-rule (WTR) ...