How to improve post-refractive surgery IOL power calculations

Poster Details

First Author: D.Stephenson USA

Co Author(s):                  

Abstract Details

Purpose:

To evaluate if cataract surgery outcomes in post-refractive and corneal transplant patients can be improved with the use of an intraoperative wavefront aberrometers to calculate the IOL power prior to implantation.

Setting:

Private, multispecialty surgery center in Venice, FL, US

Methods:

Case studies of patients who had undergone previous radial keratotomy for myopia, hyperopic and myopic LASIK and keratoconic patients who had undergone corneal transplants will be presented. Pre-operatively, all patients underwent a standard work-up that include the IOL Master, corneal topography and an OCT exam. Haigis L , Holladay 1 & 2, SRK-T and the ASCRS post-refractive IOL formula were all used to calculate the appropriate IOL power. Intraoperative, all patients underwent routine cataract surgery, at the end of which an intraoperative system (ORA System™, WaveTec Vision Systems, Aliso Viejo, CA) was used to perform an aphakic measurement to confirm the appropriate IOL power. Following IOL implantation, the ORA System was used again to confirm that refraction and IOL power.

Results:

In the myopic post-RK patient, the preoperative CDVA was 20/40 (-1) with a refraction of +0.75, +0.75 D @ 67°. The K readings were 42.51@ 159, 43.89 @ 69. The IOL formulas used produced a range of IOL powers form 22.5 to 24 D. Intraoperatively, the ORA System calculated an IOL power of 23.50 with a predicted residual spherical refraction of -0.28 D. A 23.50 D toric IOL with +3.50 D of cylindrical correction was implanted. A 1-month postoperative, the patient had a UCVA of 20/20, a refraction of plano and K readings of 42.45 @ 150°, 44.23 @ 60°.

Conclusions:

IOL calculations in eyes that have had previous corneal surgery are well known to produce less than predictable results in cataract patients. The use of an intraoperative wavefront aberrometers can help to improve predictability, reducing the need for surgical enhancements, while improving patient satisfaction. FINANCIAL DISCLOSURE?: No