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Limbal Relaxing Incisions.


Improving outcome predictability

My friend Rafi Israel in California has has adjusted the output of the
PalmScan AP2000 LRI equation to account for the fact that LRIs also need to consider corneal rigidity, which is a function of both IOP and corneal thickness.

As we learned in college (when we were paying attention), the tension on the wall of a sphere, such as the cornea, can be described by LaPlace's Law, where...
 

The tension (T) in the spherical object...
with a wall thickness of (d)...
and the internal pressure (p)...
and the radius of (r) is:

T = (p*r) / (2d)

  La Place Law

Limbal relaxing incisions

The more rigid the cornea, the more effective will be the cut and the thicker the cornea, the deeper the cut will need to be in order to have the desired effect. This is a very well-reasoned approach and Dr. Israel has shown that applying a correction based on LaPlace's Law does indeed increase the accuracy of the exercise.

Follow this link for a more detailed explanation: Micro Medical Devices (no financial interest).

LRI's carried out in this manner require an adjustable diamond blade and a good method of intraoperative marking. What many consider to be the best instruments for this purpose can be found at: Mastel Precision (no financial interest).

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