To compare image quality due to higher-order aberrations following laser in situ keratomileusis (LASIK) or implantation of phakic intraocular lens (PIOL) to correct high myopia.
Postoperative ...wavefront examinations, normalized to a pupil size of 5.5 mm, were obtained for 19 LASIK and 20 PIOL eyes for the same surgeon over the same time period. Higher-order aberrations and simulated retinal images were compared.
For this small sample, the LASIK eyes yielded an average three times more spherical aberration and two times more coma than PIOL eyes. The effects of these differences were visualized using the simulated retinal images.
Spherical aberration and coma are the major differences between postoperative LASIK and PIOL higher-order aberrations, and simulated retinal images can be used to visualize these effects.
To evaluate the forward shift of the posterior corneal surface after myopic laser in situ keratomileusis (LASIK) relative to the residual stromal bed thickness and the ablation percentage of the ...total corneal thickness.
Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Ilsan, Korea.
Three hundred sixty-three eyes of 182 consecutive patients who had LASIK were examined retrospectively. The range of the refractive errors was −1.5 to −12.0 diopters. Corneal topography using Orbscan
® II (Bausch & Lomb) and pachymetry were obtained preoperatively and 1 week and 1, 2, and 3 months postoperatively. The patients were divided into 4 groups based on the residual stromal bed thickness: Group 1, 145 eyes with less than 250 μm; Group 2, 129 eyes with 250 to 300 μm; Group 3, 76 eyes with 300 to 350 μm; and Group 4, 13 eyes with more than 350 μm. They were also grouped by the ablation percentage per total corneal thickness: Group A, 16 eyes with less than 10%; Group B, 166 eyes with 10% to 20%; Group C, 146 eyes with 20% to 30%; and Group D, 35 eyes with more than 30%.
The increase in the forward shift of the posterior corneal surface postoperatively correlated with the residual corneal bed thickness and the ablation ratio per total corneal thickness. There were no statistically significant changes in the postsurgical forward shift of the posterior corneal surface if the residual corneal thickness remained greater than 350 μm or the ablation percentage was less than 10%.
Increased forward shift of the posterior corneal surface is common after myopic LASIK and correlates with the residual corneal thickness and the ablation percentage per total corneal thickness. An excessively thin residual corneal bed or a large ablation percentage may increase the risk of iatrogenic complications.
To assess the efficacy of the Toric Implantable Collamer Lens (ICL) to treat moderate to high myopic astigmatism.
Prospective nonrandomized clinical trial.
Two hundred ten eyes of 124 patients with ...between 2.38 and 19.5 diopters (D) of myopia (spherical equivalent SE) and 1 to 4 D of astigmatism participating in the United States Food and Drug Administration clinical trial of the Toric ICL.
Implantation of the Toric ICL.
Uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), adverse events, and postoperative complications.
At 12 months postoperatively, the proportion of eyes with 20/20 or better UCVA (83.1%) was identical to the proportion of eyes with preoperative 20/20 or better BSCVA (83.1%); 76.5% had postoperative UCVA better than or equal to preoperative BSCVA. The mean manifest refractive cylinder dropped from 1.93 D (+/-0.84) at baseline to 0.51 D (+/-0.48) postoperatively, a 73.6% decrease in astigmatism. Although only 21.0% of eyes had 1-D refractive cylinder preoperatively (none less), 91.4% of cases had < or =1 D of cylinder postoperatively. Furthermore, 65.6% had < or =0.5 D and 40.9% had < or =0.25 D of refractive cylinder postoperatively. Mean manifest refraction SE (MRSE) improved from -9.36 D (+/-2.66) preoperatively to 0.05 D (+/-0.46) postoperatively. A total of 76.9% of eyes were predicted accurately to within +/-0.5 D, 97.3% to within +/-1.0 D, and 100% to within +/-2.0 D of predicted MRSE. Postoperatively, 37.6% of eyes had a BSCVA of 20/12.5 or better, compared with a preoperative level of 4.8%. Furthermore, BSCVA of 20/20 or better occurred in 96.8% postoperatively, compared with 83.1% preoperatively. Mean improvement in BSCVA was 0.88 lines; there were 3 cases (1.6%) that lost > or =2 lines of BSCVA after 12 months postoperatively, whereas 18.9% of cases improved by > or =2 lines. A total of 76.4% of cases gained > or =1 lines of BSCVA, whereas only 7.5% of cases lost the equivalent amount. Three ICL removals were performed without significant loss of BSCVA, and 1 clinically significant lens opacity was observed.
The results support the efficacy and predictability of Toric ICL implantation to treat moderate to high myopic astigmatism. Important safety concerns were not identified.
To evaluate the clinical acceptability of monocular implantation of the small-aperture (IC-8) intraocular lens (IOL) in 1 eye and an aspheric monofocal IOL in the fellow eye of bilateral cataract ...patients over 6 months postoperatively.
Twelve clinics in Austria, Belgium, Germany, Italy, Spain, and Norway.
Prospective case series.
The visual acuity, depth of focus, contrast sensitivity, patient satisfaction, visual symptoms, and adverse events were assessed in patients who had bilateral cataract surgery followed by implantation of the small-aperture IOL in 1 eye and an aspheric monofocal IOL in the fellow eye. Uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuities were reported in Snellen notation.
The study comprised 105 patients. At 6 months, the UDVA, UIVA, and UNVA in eyes with the small-aperture IOL were 20/23, 20/24, and 20/30, respectively. Ninety-nine percent, 95%, and 79% of patients achieved 20/32 or better binocular UDVA, UIVA, and UNVA, respectively. Ninety-three patients (95.9%) reported they would have the procedure again versus 4 patients (4.1%) who reported they would not have the procedure again. In eyes with the small-aperture IOL, the target-corrected defocus curve measured with 0.75 diopter (D) of myopia extended the range of functional near vision by an additional diopter without loss of distance vision compared with the distance-corrected defocus curves. The mean UIVA and UNVA remained at 20/25 and 20/32, respectively, for up to 1.5 D of residual astigmatism in eyes with the small-aperture IOL.
The small-aperture IOL showed excellent visual performance, safety, patient satisfaction, and tolerance to residual astigmatism 6 months after implantation.
To assess the efficacy of high-frequency ultrasound biomicroscopy (UBM) in improving the accuracy of phakic intraocular lens (pIOL) sizing by increasing the incidence of acceptable postoperative ...vault.
Multiple private practices, United States.
Evaluation of diagnostic test or technology.
This prospective multicenter clinical study evaluated eyes having pIOL (Visian Implantable Collamer Lens) implantation. A retrospective data analysis was performed using UBM measurements (VuMax-II) of preoperative sulcus-to-sulcus (STS) distance and postoperative vault. The regression data and clinical input from investigators were then used to develop a pIOL sizing nomogram. The nomogram used only STS and pIOL power as variables to determine length. Inadequate vault (<90 μm) and excessive vault (>1000 μm) were defined based on peer-reviewed literature. Sizing recommendations using the nomogram were studied prospectively and compared with 2 sizing methods used in the United States that are based on white-to-white (WTW) measurements.
One eye was excluded from the analysis because the wrong length pIOL was placed (12.6 mm instead of nomogram-recommended 13.2 mm), resulting in 51 μm of vault. The mean postoperative vault in the remaining 72 cases was 340 μm ± 174 (SD) (range 90 to 952 μm); there were no cases of inadequate or excessive vault with the newly developed UBM nomogram. Sizing methods using WTW measurements would have resulted in different-sized pIOLs in 36% to 69% of cases compared with the STS method.
There were no cases of inadequate or excessive vault when the UBM nomogram for pIOL sizing was used.
No author has a financial or proprietary interest in any material or method mentioned.
To report adverse device effects and annualized endothelial cell loss rate for up to 10 years after implantation of the Acrysof L-series Cachet phakic intraocular lens (pIOL).
Clinical centers in the ...United States, European Union, and Canada.
Nonrandomized clinical trial.
After implantation of the pIOL, the endothelial cell density (ECD) at follow-up evaluations was compared with the 6-month postoperative baseline. Adverse device effects were assessed.
This study assessed 638 patients (1087 eyes) from previous clinical trials. The mean central ECD change from baseline was −9.6% ± 8.3% (SD) (−1.7% annualized; 623 eyes) and −11.0% ± 9.9% (−1.7% annualized; 703 eyes) at 6 years and 7 years, respectively. The mean peripheral ECD change from baseline was −10.8% ± 8.7% (−2.0% annualized; 615 eyes) and −11.9% ± 10.0% (−1.8% annualized; 680 eyes), respectively. Endothelial cell loss greater than 30% from the preoperative baseline at any time after implantation affected 8.0% of all eyes. An ECD of 1500 cells/mm2 or less at any time after implantation affected 2.7% of all eyes. The most common adverse device effects were peripheral iris adhesions (57 eyes 5.2%), corneal endothelial cell loss (42 eyes 3.9%), and pIOL explantation (37 eyes 3.4%).
Long-term evaluation of the pIOL showed a persistent ECD decrease in some eyes that was numerically larger than the annual rate expected with aging. Endothelial cell loss resulted in explantation in 3.1% of all eyes with the pIOL. Patients had no permanent vision loss. The manufacturer recommends that patients continue to be monitored and their corneal endothelium evaluated semiannually.
Lens offering surgeons a reassuring amount of resistance to movement in the eye THE TECNIS TORIC II (ZCU) lens (Johnson & Johnson Vision) will be very familiar to any surgeon who has implanted other ...intraocular lenses (IOLs) from the Tecnis platform. Lens position was evaluated using 2 masked readers and custom image analysis software to compare the positions of 10 different iris and scleral landmarks (Figure 2) in photographs taken at the end of the surgery (through the operative microscope) and at the slit lamp at postoperative follow-up visits.4 This digital photographic comparison is the most robust method I have seen for measuring rotational stability. Canovas C, Piers P, Sun M, Alarcon A, Weeber HA, Waring G. Impact of residual astigmatism on optical and visual performance for toric intraocular lenses.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK, VSZLJ
