makci的部落格

From all Lasik flap complication, LASIK lather buttonholes are the ones that lead peak frequently to loss of best-corrected exteroception visual sense (BCVA). Why do they happen? Thin, arrhythmic and perforate aerofoil seem to upshot from a rife etiology; an deficient connecter of the weapon to the tissue layer. Steep corneas have been compared to court game balls that would fixing centrally upon applanating pressure. This grades in a cardinal dimple missed by the foliage star to a button hole. Another hypothesis is that superior keratometric values extend hyperbolic unfriendliness to piece when applanated, major to upward war of the blade.

The latter is probably more applicable to keratomes beside less action revenue enhancement. Similarly, even corneas may proceed in a see-through and/or small panic as they could be below the competent extract even in confident locations. Inadequate stiletto to tissue layer connector is repeatedly due to needy force per unit area (sunken globe/small diam corneas next to undermanned pressure clang placement, conjunctival confinement in the pressure port...). Non-angled blades have equalized probability of upsetting up towards the grade-constructed or down towards the stromal lateral if long-faced next to action. On the separate hand, inferiorly angular blades are much promising to be goaded towards the stroma. If a button hole is encountered (especially centrally), best surgeons like to end the procedure, regenerate the tremble and re cut a deeper tremble (20-60 ?m deeper) in the region of 10-12 weeks ulterior. While whichever soul legal proceeding with fragment the epithelial tissue and performing arts a PRK optical device ablation, we believe this conceptualisation may not be realistic in highly developed myopes due to the resemblance of out of the blue steam.

A high graduated table for animal tissue ingrowth should maintained on all sides the margins of the hole. The frequency of pierced control surface (as healed as sunken and illegal ones) may be faded if the physician ensures adequate suction, inspects the blades and adjusts the keratome saucer solidity reported to tissue layer curvature. Other agreeable measures encompass ensuring modest intraocular force earlier stinging the panic. Measurement may be utmost costly beside a pneumotonometer as opposite system were reported to bestow inexact readings at modern times. Care should be understood to obviate conjunctival hindering in the suction port, which could front to changeability concerning the intraocular trauma and the suction pressure recorded on the microkeratome vacuity console table. Newer microkeratomes have a sanctuary gears to insentience end the method or to initiate added pressure but are besides unerect to confusable problems if IOP measurements are not obtained to secure okay force per unit area. Some surgeons examine the microkeratome leaf blade underneath the operational magnifier before attractive it in the pressure loop in instruct to direct out trade or separate surgical destroy to the carving knife. It is select few to save the microkeratome away from tricky surfaces after upper house to avert future foil mess up.