Even without refned nomograms, new-generation aberrometry is contributing to better results
We have consistently found that uncorrected distance vision is the best predictor of patient satisfaction after laser vision correction. Moreover, every line of visual acuity, even beyond the 'ideal' of 20/20, results in greater patient satisfaction with the procedure and a greater likelihood of positive referrals.
Optical Express centres in the UK have been evaluating the efficacy of a new high-resolution aberrometer (iDesign, Abbott Medical Optics, Santa Ana, California, USA) for wavefront-guided laser vision correction.
Study design and results
The performance of the new aberrometer was evaluated in 675 eyes of 348 patients undergoing refractive surgery between May and October 2012. These patients presented with a wide range of preoperative refractive error. Preoperative sphere ranged from –9.50 D to +4.25 D (mean: –1.86 ± 2.42 D) and preoperative cylinder was as much as 5.50 D in some eyes (mean: –0.76 ± 0.83 D).
At one month, 90% of all eyes had a manifest spherical equivalent (MSE) within 0.50 D of intended correction and 97% were within 1.00 D. The linear regression for attempted versus achieved MSE was 1.01, with a very strong correlation coefficient (0.97). Monocular uncorrected visual acuity (UCVA) was 20/25 or better in 93% of eyes and 20/16 or better in more than 70% of eyes.
Most impressive were the astigmatism correction results. One month postoperatively, the mean cylinder had been reduced to –0.18 ± 0.25 D, and 95% of the eyes had visually insignificant (less than 0.5 D) of cylinder. This is the best cylinder correction I have ever seen following an excimer laser procedure.