PURPOSE: To investigate central multifocal presbyLASIK based on the creation of a central hyperpositive area.
METHODS: Twenty-five patients (50 eyes) underwent presbyLASIK in an open-label, prospective, non-comparative pilot study. Mean patient age was 58 years (range: 51 to 68 years), mean preoperative spherical equivalent refraction was +1.6 ± 0.63 diopters (D) (range: +0.50 to +3.00 D), and mean spectacle near addition was +2.27 ± 0.37 D (range: +1.75 to +3.00 D). The ablation pattern was performed with proprietary software from Technovision using an H. Eye Tech. excimer laser platform.
RESULTS: Mean postoperative spherical equivalent refraction was -0.37 ± 0.55 D (range: -1.50 to +1.00 D) and mean spectacle near addition was +1.72 ± 0.34 D (range: +1.25 to +2.25 D). After 6 months, 16 (64%) patients achieved a distance uncorrected visual acuity (UCVA) of ≥20/20 and 18 (72%) patients achieved a near UCVA of ≥20/40. Seven (28%) patients lost a maximum of 2 lines of best spectacle-corrected visual acuity (BSCVA). The safety index for distance was 0.98 binocular and for near was 0.99 binocular. After 6 months, no significant change was noted in contrast sensitivity at 1.5 cycles/degree. A significant mean reduction was found at spatial frequencies of 3, 6, 12, and 18 cycles/degree (P<.001). There was a significant change in corneal aberrations after surgery. The coefficients for coma increased and the coefficients for spherical aberrations decreased. A significant decrease was noted in point spread function values (P=.0018).
CONCLUSIONS: Central presbyLASIK may be used to provide improvement in functional near vision in patients with presbyopia associated with low and moderate hyperopia. However, factors involved in the loss of BSCVA in some cases and loss in vision quality should be further clarified prior to its general use. [J Refract Surg. 2006;22:453-460.]
No significant differences were observed in LMCSF among the different mfIOLs studied. The third focus of trifocal IOL models did not adversely affect the LMCSF. The ReSTOR SN6AD1 showed the poorest LMCSF for the highest spatial frequency analyzed when compared with the control group.
Significant correlations were found between logMAR visual acuity and image quality metric for the multifocal and monofocal IOLs analyzed. This finding enables surgeons to predict visual outcomes from the optical bench analysis.
PURPOSE: To evaluate the changes in the optical quality of corneas of hyperopic patients operated using central multifocal presbyLASIK treatment through the study of light patterns around the retinal plane.
METHODS: This study included eight hyperopic eyes that underwent central presbyLASIK surgery with Presby-one software using an H. Eye Tech Technovision excimer laser platform. Mean patient age was 57 years. Mean preoperative spherical equivalent refraction was 1.28±0.87 diopters (D). Mean distance decimal visual acuity with correction was 1.02±0.13 and without correction was 0.37±0.15. The optical quality was characterized by the Strehl ratio, the spot size on the retina, and objective decimal visual acuity calculated based on measured corneal topography using Fresnel propagation algorithm based on a realistic eye model.
RESULTS: The postoperative spherical equivalent refraction was -0.55±0.48 D. The distance decimal visual acuity with correction was 0.94 and without correction was 0.70. The pseudoaccommodation range was 1.60±0.40 D. A good Pearson correlation coefficient was obtained (r
p 2
=0.86) for the linear fit between the real and calculated decimal visual acuity for the eight eyes. The Strehl ratio value on the retinal plane increased after the surgery by a mean factor of 4.7.
CONCLUSIONS: With a complete characterization of the eye and a complete propagation algorithm (that takes into account all refractive surfaces in the eye at the same time), it is possible to evaluate the optical quality in eyes of patients who have undergone central presbyLASIK treatment. [J Refract Surg. 2007;23:39-44.]
The angle-supported pIOL showed excellent intraocular behavior after pupil dilation, with no shortening of the distance between the pIOL and corneal endothelium at the center or peripheral edges of the pIOL.
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