Session Title: Cataract I
Session Date/Time: Friday 15/02/2013 | 10:30-12:30
Paper Time: 12:04
Venue: Hall 2
First Author: : C.Arce BRAZIL
Co Author(s): :
Purpose:
To search the topographic patterns of anterior and posterior corneal astigmatism as well as determining its relative prevalence at different ages.
Setting:
Private Eye Clinic.
Methods:
Dual Scheimpflug and Placido anterior segment analyzer was used to determine the topographic patterns of anterior and posterior corneal astigmatism in diopters, their axis and their prevalence at different age ranges in the population that were examined in a private eye center.
Results:
Anterior and posterior corneal astigmatisms may have similar coincident or different non-coincident axis. Most common combination at all ages was anterior and posterior with-the-rule. Less frequent was anterior and posterior against the rule. Crossed anterior with the rule and posterior against the rule seem to increase in frequency with age. Combination of anterior with the rule and posterior against the rule is extremely rare if it really exists in virgin corneas.
Conclusions:
It was recently suggested posterior negative astigmatism in diopters should be considered to improve preoperative toric IOL calculation. The knowledge of how it relates with the anterior astigmatism is extremely important to apply the suggested fudge factors in the calculation of cylinder power of toric IOLs.
When there is coincidence of the axis of anterior and posterior corneal cylinder, posterior astigmatism subtracts from anterior to obtain the total corneal astigmatism. When corneal anterior and posterior astigmatism is crossed, posterior cylinder adds to the anterior.
Financial Disclosure:
... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, ... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented
