This year's meeting will feature the latest results with a variety of laser systems used for customised ablations. The systems use aberrometry with or without topography to guide the ablations, or use an optimised ablation profile with the aim of producing an ideal corneal curvature.
Ermanno Scerrati MD, Frosinone, Italy, will be presenting his preliminary results using Nidek's Navex system (Friday, Super Vision I, 17:00-19:00). The Navex system captures each patient's refractive wavefront and corneal topography data and converts them into a combined refractive power map.
The system also includes software that calculates the precise customised algorithms to guide the ablation of the Nidek EC-5000CX excimer laser.
In 10 eyes of 10 patients who underwent myopic corrections with LASIK using the NAVEX system, UCVA was 20/15 or better in 50% of eyes and 20/20 or better in 30% at three months follow-up.
Best-corrected visual acuity improved by one line in five eyes and remained unchanged in the remaining eyes. The mean postoperative refraction was +0.4 D. In addition, OPD Scan analysis showed that the total RMS decreased by 60.4% from its preoperative value."Customised ablation with the Nidek Navex system was stable, predictable, efficient and safe. In addition, there was a significant decrease of RMS total, which means an increase in the quality of vision,"
Optimised aspheric profile
Frank Goes MD, Antwerp, Belgium will be reporting one-year results with the Zeiss Mel 80 laser, a spot scanning laser with a frequency rate of 250 Hz and an optimised aspheric ablation profile (Saturday, Super Vision III, 15:00-15:45).
Dr Goes' study involved 76 eyes undergoing LASIK to correct from -1.00 D to -9.00 D of spherical error and up to -3.0 D of cylinder. At 12 months' follow-up UCVA was 20/20 or better in 83% and 20/15 or better in 50%. The postoperative mean spherical equivalent was 0.13 D.
All eyes were within 1.0 D of intended correction, 96% were within 0.5 D, and 78% were within 0.25 D. Some 54% of eyes gained one line or more of vision and 17% gained two lines. Furthermore, aberrometry with the system's WASCA unit showed no significant increase of higher order aberrations. Mean RMS levels changed from 0.201 microns before surgery to 0.286 microns afterwards.
"The MEL 80 with its aspheric and optimised ablation profile produced extraordinary clinical outcomes without induction of higher-order aberrations. The safety, accuracy and predictability as well as the extremely fast recuperation of BCVA were outstanding features."
Corneal wavefront
Jorge L. Alio MD PhD, Alicante, Spain will report on results he has obtained with corneal wavefront-guided LASIK using the ESIRIS laser (Schwind) and the ORK-W program in the treatment of irregular astigmatism after previous corneal refractive surgery (Saturday, SuperVision symposium, 16:00-18:00).
Dr Alio study involved 16 eyes with macro-irregular or mixed macro and micro-irregular astigmatism. All underwent LASIK using the Schwind system.
At six months' follow-up, 85% of the patients gained at least one line of BCVA.
There were also statistically significant reductions in coma and spherical aberration in all eyes. Improvements in point spread function and global RMS indicated corresponding improvements in quality of vision."The corneal wavefront-guided LASIK technique is an excellent option to treat irregular astigmatism induced by previous corneal refractive surgery. "
Wavefront enhancements
Francesco Carones MD, Milan, Italy, will be presenting results preliminary results form a study involving nine highly aberrated eyes of nine patients who underwent wavefront-guided custom ablation using the LADARVision platform, which guides the ablation based on a patient's overall wavefront (Friday, SuperVision I, 17:00-19:00).
Included in the study were six patients who underwent customised LASIK enhancement after previous conventional LASIK, one patient who underwent customised LASIK after previous radial keratotomy, and two patients without previous treatment who underwent customised PRK.
After a follow-up of three to 10 months all eyes had an improvement in UCVA. Five eyes gained one line of BSCVA line; two eyes gained two lines, while no eyes lost lines. Furthermore, all eyes had reductions in pre-existing higher-order aberrations, which ranged from 3% and 64%.
The greatest wavefront error reductions were for spherical aberration, which fell by an average of 44%. Coma was reduced by 17%, and all other terms were reduced by 19% compared to preoperative values. Moreover, all patients reported a consistent reduction in their pre-existing visual symptoms.
Dr Carones noted that the manifest refraction spherical equivalent was slightly hyperopic in all eyes (+0.12 D to +1.50 D)."Wavefront-guided custom ablation proved effective in reducing higher-order aberrations and related visual symptoms in this preliminary small series."
