Angle alpha and angle kappa and multifocal IOL
Votre question :
Dear Dr. Gatinel.
Do you measure alpha and kappa angles as preoperative test before implanting multifocal IOL? If yes, What method do you use?
Juan Pablo Garcés C, MD
Medellín – Colombia
Notre réponse :
The direct measurement of the kappa and alpha angle is not provided by instruments such as corneal topographs. Instead, they provide the distance between the photopic and mesopic pupil centers to the corneal vertex. This data is an indirect estimation of the kappa angle, being grossly proportional to it. For example, the Nidek OPDscan provides such measurement of the PD (Photopic distance of the pupil center to vertex) and MD (Mesopic distance of pupil center to vertex). When this distance is large (ex >600 microns), some surgeons may be concerned that the optical quality of the implanted eye may suffer when an multifocal IOL is implanted. I have not been exposed to severe problems that could be linked with certainty to such situation, at least with diffractive IOLs such as the Finevision.