IOLMaster Haigis-L Frequently Asked Questions

= ij~ëíÉê ê∆== fli e~ááÖáëJi= Frequ uently Asked d Questions Why does d the Haiigis-L formula work with the IOLMastter only? The Haigis-L H works s with the IOL LMaster beca ause it uses th he smaller (ap pprox 2.5 mm m) keratomete er measurement radiu us of the IOLM Master, which h gives a morre clinically re elevant anterio or curvature for po ost-myopic LV VC power calcculation. ents with las ser correction can benefiit with the Ha aigis-L formu ula? Whatt type of patie Haigiss-L works for post-myopic or post-hyperropic laser vission correctio on (LASIK, PR RK, LASEK, epi-LA ASIK). It does s not work forr RK. Warren Hill MD webssite describess methods for post RK and hyperropic LASIK using u the ATLAS corneal to opographer (w www.doctor-h hill.com) meters are ne eeded with th he Haigis-L? Whatt input param Haigiss-L uses the same s measurrements as th he regular Haigis formula (axial length, keratometry k and anterior a chamb ber depth). Why does d it work k even if the posterior p surrface curvatu ure of the co ornea is not measured? m Unlike e other formulas, Haigis-L does not use e measure corrneal curvaturre to predict the t postoperative lens position and is therefore not n compromiised by a form mula specific error. e Dr. Haigiss established a correlation between corrneal power based on IOLM Master kerato ometer measurements and d those derive ed from cliniccal history. A correction c facctor was then applied to the e standard Haigis forrmula based on this correlation function n, resulting in the Haigis-L formula. Whatt lens consta ants are used d with the Ha aigis-L formu ula? The le ens constants s used for the e Haigis formu ula are (a0, a1 1 and a2). d the Haiigis-L use th hree constantts (a0. a1 and a2)? Why does For th he Haigis and Haigis-L form mulas, the a0 constant moves the powe er prediction curve c up, or down. The a1 cons stant is tied to o the measure ed anterior ch hamber depth h and the a2 constant c is tie ed to the e measured ax xial length. Th herefore, the a1 and a2 co onstants are used u to vary th he shape of the po ower predictio on curve and they change the power ba ased on the ce entral corneal power, anteriior chamber depth d and individual lens geometry. g

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