Joja Surgicals Pvt. [email protected]
This presentation is issued in scientific interest to promote better marking techniques for Toric IOL implantation, LRIs and refractive surgeries
The tool and software described in this presentation are patented / copyrighted
This is not an advertisement
Why is Marking Important?For every degree of rotation 3.3% of the effect is lostWith 30 degree rotation all effect of the Toric lens is lostBeyond that you start adding to the astigmatism
Why is Marking Important?Higher the Toric correction greater the chances of errorse.g. For a 5 degree misalignmentIn a 6 D Toric error is 1 DIn a 1.5 D Toric error is 0.25 D
So lets get the marking spot on !Two issues in markingMaking sure our 0 180 meridian is true horizontalMaking sure that the marks bisect the cornea through the optical centre
Current MarkersHand held markersWith spirit level to ensure horizontality
Current MarkersDo not ensure that the marks pass through the centre of the cornea
Are you bisecting the cornea?
Current MarkersYou also need a second intra-op mark if the placement axis is not 0 180
Current MarkersCome in only one sizeBut the corneas are not of the same size or shape!
IssuesStill does not solve the problem of bisecting the cornea through the optical centre
A New ApproachA slit lamp based systemUses gravity to define horizontalUses Purkinje images to ensure centring on the cornea
3 Simple StepsSet the slit lamp beam to the desired placement axisAlign the beam to pass through the corneal centre (described later)Mark the cornea
Step 1 Setting the AngleThe slit beam can be set to the axis of placementNo need for reference markingClamp device to chin rest of slit lamp
Setting the Angle
Step 2Unclamp the calibrator devicePlace the patients head normally on the slit lamp
Centring on the CorneaPatient looks at the light with the other eye closedMove the slit beam across the cornea until you get a bright Purkinje image
Centring on the CorneaImages bordered in red show the correct positioning of the slit beam
Centring on the Cornea
How do we know it is accurate?
Planiware 2.0This is a IOL planimetry software designed for measuringCentration of IOL, rhexis, pupilMeasurement of rhexis / pupil areas and diametersAngular measurements of Toric IOLs
Planiware can be downloaded from www.suryodaya.in/planiware
Verifying your markings
*