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Updated: Oct 1, 2026
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Laser in situ keratomileusis with the Nidek EC-5000 excimer laser for astigmatism greater than 4.00 D
Marcelo Mastromonico Lui1, Marcia Ap Grandini Silas, Benny Apelbaum
1Laser Vision, Guarulhos, São Paulo, Brazil. marcelolui@cmcsidimagem.com.br
Purpose:
To evaluate laser in situ keratomileusis (LASIK) performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D.
Methods:
LASIK was performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D. Based on Chayet's nomogram, ablation zone diameters were 5.5 mm (steep meridian ablation) to 7.5 mm (flat meridian ablation). In eyes with simple myopic astigmatism, mixed astigmatism, and compound myopic astigmatism (low sphere), ablation was performed in both meridians. In eyes with simple hyperopic astigmatism, ablation was performed in the flat meridian alone. In eyes with compound hyperopic astigmatism, ablation zone diameter was 5.5 mm and the transition zone was 7.5 mm.
Results:
Uncorrected visual acuity was 20/40 or better in 89% of eyes and was equal to preoperative best spectacle-corrected visual acuity in 62% of eyes. No eyes lost lines of best spectacle-corrected visual acuity.
Conclusions:
Using the Nidek EC-5000 excimer laser, we had satisfactory results in the treatment of astigmatic eyes with cylinder from 4.00 to 8.00 D, based on Chayet's nomogram.