Higher-order aberrations after implantation of iris-fixated rigid or foldable phakic intraocular lenses

Short-term clinic observation of misalignment and rotational stability after implantable collamer lens implantation

PURPOSE

We aimed to investigate misalignment (tilt and decentration) and rotational stability of the implantable collamer lens V4c 6 months after implantation and to explore the potential risk factors associated with postoperative misalignment and rotation.

METHODS

A total of 36 eyes of 36 patients with high myopia and myopic astigmatism who underwent implantable collamer lens V4c implantation were included in this study. Tilt, decentration, and rotation of the implantable collamer lens were assessed postoperatively at l week, 1 month, 3 months, and 6 months. Correlation analysis was used to identify the potential risk factors for implantable collamer lens tilt, decentration, and rotation at 6 months postoperatively. Higher-order aberration was measured to evaluate the effect of implantable collamer lens misalignment on visual quality at pupil diameters of 4.0 mm and 6.0 mm.

RESULTS

The tilt and decentration at the last follow-up were 2.43 ± 1.35° and 0.278 ± 0.160 mm, respectively. There was a significant positive correlation between tilt and decentration (r = 0.31, P = 0.046). No significant correlation was detected between implantable collamer lens decentration and internal higher-order aberrations (P > 0.05). The degree of implantable collamer lens rotation (3.11 ± 2.00°) was significantly associated with the vault (r =  - 0.422, P = 0.01), while it was positively associated with the preoperative anterior chamber depth (r = 0.36, P = 0.034). No significant correlation was found between postoperative astigmatism and rotation (r =  - 0.07, P = 0.351).

CONCLUSIONS

The implantable collamer lens V4c provides relatively stable misalignment and rotation after implantation. The ICL lens vault is a potential risk factor for postoperative implantable collamer lens rotation. The absolute value of decentration and tilt was relatively small, which showed no correlation with internal higher-order aberration in short-term observation.

Comparison of the visual performance of iris-fixated phakic lens and implantable collamer lens to correct high myopia

Background

To compare visual performance between the iris-fixated phakic intraocular len (pIOL) and implantable collamer len (ICL) to correct high myopia.

Methods

Twenty-four eyes underwent iris-fixated pIOL implantation and 24 eyes underwent ICL implantation. At the 6-month follow-up, the best-corrected visual acuity (BCVA) and uncorrected distance visual acuity (UDVA) were compared between the iris-fixated pIOL and ICL groups. The objective scatter index (OSI), modulation transfer function (MTF) cutoff, and ocular aberrations were performed to evaluate postoperative visual quality between the two groups.

Results

No significant difference was found in UDVA, BCVA, and spherical equivalent between the iris-fixated pIOL and ICL groups (P > 0.05). Six months after surgery, the following values were significantly higher in the ICL group than in the iris-fixated pIOL group: MTF cutoff, strehl ratio and optical quality analysis system values at contrasts of 9 %, 20 %, and 100 % (P < 0.01). The OSI in the iris-fixated pIOL group was higher than in the ICL group 6 months after surgery (P < 0.01). All high-order aberrations were slightly more severe in the iris-fixated pIOL group than in the ICL group 6 months after surgery, although only trefoil (P = 0.023) differed significantly in this regard.

Conclusions

Both iris-fixated lenses and ICLs can provide good visual acuity. ICLs confer better visual performance in MTF-associated parameters and induce less intraocular light scattering than iris-fixated pIOLs.

Artisan versus Artiflex phakic intraocular lens implantation in the treatment of moderate to high myopia: meta-analysis

Background

To compare the postoperative safety, efficacy, predictability, visual quality and biomechanics after implantation of Artisan vs. Artiflex phakic intraocular lenses (PIOLs).

Methods

Pubmed, Embase, Cochrane Library were conducted up from January 2000 to February 2020. Comparative clinical studies reporting in accordance with the eligibility criteria were included in this meta-analysis. The pooled weighted mean differences (WMDs) and odds ratios (ORs) with corresponding 95% confidence intervals were calculated.

Results

Comparative trials with myopia patients were selected in this review. The pooled WMD and OR estimates statistical significance in terms of postoperative best corrected visual acuity (BCVA), efficacy, postoperative spherical equivalence (SE), predictability, contrast sensitivity and mean intraocular higher-order aberrations (HOA) (mm) for a 6-mm pupil, manifesting that Artiflex PIOL showed evident beneficial effect for correcting myopia compared to Artisan PIOL. There was no significant difference in the incidence of complications between the two groups.

Conclusion

Both of two techniques were safe and effective for myopia and compared to Artisan PIOL, Artiflex PIOL had significant improvement in efficacy, predictability, contrast sensitivityand HOA, except safety and complications in the treatment of moderate to high myopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01930-6.

Visian® ICLV4c™ and Artiflex®: Comparative Analysis with the HD AnalyserTM and Integration with Subjective Performance and Anatomical Parameters

Purpose

To analyze and compare the mid-term objective and subjective performance of two phakic intraocular lenses (PIOLs) – Visian^® ICL™ V4c and Artiflex^® and to correlate those results with anatomical parameters.

Patients and Methods

Observational retrospective study including thirty patients (15 for each PIOL) randomly selected from those who underwent bilateral implantation of one of the PIOLs (60 eyes were analysed). Uncorrected and corrected distance visual acuities (UDVA and CDVA), anterior chamber structural parameters, and corneal endothelial cells density and morphology were evaluated. Quality of vision was assessed both subjectively with a questionnaire, and objectively using a double-pass technology optical quality analysis system.

Results

At the end of follow-up the Artiflex^® group showed better UDVA (0.95±0.11 vs 0.99±0.05, p=0.027) and higher proportion of eyes reaching at least 20/20 (28/30 vs 18/30, p=0.005). Excellent and similar objective scatter index (1.79±0.9 vs 2.14±1.6, p=0.306) and modular transfer function cutoff frequency (26.91±9.2 vs 26.51±11.9, p=0.784) results were achieved in the HD Analyzer^® and the questionnaire showed comparable high Satisfaction (55.7±3.5 vs 54.3±5.4, p=0.386) and low Dysphotopsia Scores (3.1±1.8 vs 2.1±2.2, p=0.213). The ICL group showed inferior anterior chamber volume (p<0.001), and angle (p<0.001) and superior pupillary diameter (p=0.007). Minimum follow-up was 24 months.

Conclusion

Both the Visian^® ICLV4c™ and the Artiflex^® showed excellent optical performance through the HD Analyzer^TM technology, translated in high patient satisfaction. Overall, both PIOLs showed similar safety, predictability, stability and effectiveness of for the reduction of high sphero-cylindrical refractive errors, despite better UDVA results with the Artiflex^®.

Phakic intraocular lenses: An overview

Phakic intraocular lenses (pIOLs) are a common solution for the surgical correction of high myopia and myopia in thin corneas. Global trends result in increasing rates of patients with high myopia which will result in increased rates of pIOL implantation. Three types of lenses can be distinguished: anterior chamber angle-supported, anterior chamber iris-fixated, and posterior chamber phakic IOLs. The efficacy of phakic intraocular lenses is generally very good, but pIOLs have undergone many changes over the years to improve the safety profile and decrease pIOL-related complications such as endothelial cell loss, corneal decompensation and cataract formation. This article describes the efficacy and safety profiles of the most recent pIOLs, as well as suggests gaps of knowledge that are deserve additional research to optimize the results of pIOLs.

The Influence of Decentration on Higher-Order Aberrations in Artisan Aphakic Intraocular Lens Implantation Eyes

Purpose

To characterize the influence of decentration on higher-order aberrations of Artisan aphakic intraocular lens implantation eyes. Setting. Department of Ophthalmology and Vision Science, Eye and ENT Hospital of Fudan University, Shanghai, China.

Design

Retrospective case series.

Methods

Twenty-three eyes of 18 patients were retrospectively examined. Location of the IOL was imaged using a slit-lamp, and decentration (the distance from the center of a pupil to the geometric center of the IOL) was measured using the AutoCAD 2007 software. Ocular and internal higher-order aberrations were measured using the wavefront analyzer KR-1W (Topcon) and their correlation with decentration were analyzed. Coma, spherical, 3rd-, 4th-order, trefoil, tetrafoil aberrations, ocular, and internal higher-order aberrations were calculated for a 4.0 mm pupil diameter.

Results

The mean age of patients was 33.6 ± 21.4 years (ranging from 7 to 72 years). The mean follow-up period was 28.2 ± 10.5 months (ranging from 12 to 52 months). The mean postoperative best-corrected visual acuity (BCVA) was 0.19 ± 0.19 logMAR (range −0.18–0.52). The mean decentration was 0.57 ± 0.28 mm (range 0.15–1.21 mm). There was no correlation between Artisan IOL decentration and ocular higher-order aberrations, internal higher-order aberrations, coma, spherical, 3rd-, 4th-order, trefoil, and tetrafoil aberrations, respectively. There was a positive correlation between Artisan IOL decentration and 2nd-astig aberrations when 2nd-astig aberrations were less than 0.1.

Conclusions

The position of Artisan IOLs showed slight decentration and the amounts of decentration were not large enough to influence higher-order aberrations.

Comparison of rigid versus foldable iris-fixed phakic intraocular lens implantation for high myopia: A systematic review and meta-analysis

BACKGROUND

This study aimed to assess the efficacy of rigid versus foldable iris-fixed phakic intraocular lens (PIOL) implantation in the treatment of high myopia.

METHODS

A systematic search based on electronic databases such as Pubmed, Embase, and Cochrane Library was conducted to identify relevant studies published up to January 11, 2019. The pooled odds ratios and weighted mean differences (WMDs) with corresponding 95% confidence intervals were calculated.

RESULTS

Eight comparative studies with 835 participants were included in this meta-analysis. The overall WMD showed statistical significance in terms of postoperative uncorrected distance visual acuity (UDVA), mean postoperative spherical equivalence (SE), and mean postoperative intraocular higher-order aberrations (HOA) (μm) for a 6-mm pupil, suggesting that foldable PIOL group showed significant improvement of high myopia, compared to rigid PIOL group. Besides, compared with rigid PIOL group, foldable PIOL group had beneficial effect on the proportion of eyes with central endothelial cell density (ECD) loss in patients with high myopia.

CONCLUSION

This meta-analysis provided the up-to-date evidence and found that foldable PIOL group had significant beneficial effect on UDVA, SE, HOA, contrast sensitivity, and ECD, except best spectacle-corrected visual acuity, and safety in the treatment of high myopia over rigid PIOL group.

Wavefront aberration and contrast sensitivity after implantation of foldable and rigid iris claw phakic intraocular lenses: Artiflex versus artisan

Aim of study:

The aim of this study is to assess wavefront aberration and contrast sensitivity (CS) after implantation of foldable iris claw – artiflex- and rigid iris claw – artisan- phakic intraocular lenses (pIOLs).

Materials and Methods:

A nonrandomized prospective comparative case study was performed on 57 eyes; of which, 54 were myopia and 3 were hyperopia. Twenty-four patients had artisan pIOL implantation and 33 had artiflex pIOL implantation. Higher-order aberration (HOA) and CS were obtained 1 year after surgery.

Results:

Total HOA in artisan group was greater than artiflex group (P = 0.044) with a mean HOA of 0.44 ± 0.15 root mean square (RMS) for artisan and 0.35 ± 0.15 RMS for artiflex. Although, there were no significant differences in the vertical trefoil, vertical coma, horizontal trefoil, horizontal coma, secondary astigmatism, quatrefoil, and fourth order spherical aberration in two groups. CS in mesopic conditions was better in artiflex-treated eyes at three spatial frequencies of 6, 12, and 18 cycles per degree (cpd) (P = 0.003, P = 0.007, and P = 0.00, respectively), and no significant difference was seen between two lenses at 3 cpd.

Conclusion:

Although the components of HOA were not significantly different between two groups, total HOA was higher in artisan group, which may be due to the slight differences in each component, increasing the HOA as a total. CS was significantly better in artiflex group.

Comparison of three phakic intraocular lenses for correction of myopia

Purpose:

To compare the visual outcomes and complications of three different types of phakic intraocular lenses (PIOLs), for correction of moderate to high myopia.

Methods:

We reviewed 112 myopic eyes undergoing PIOL implantation using Artisan (40 eyes), Artiflex (36 eyes), and implantable collamer lens (ICL, 36 eyes). Best corrected visual acuity (BCVA), intraocular pressure (IOP), pachymetry, corneal endothelial cell (CEC) loss, and higher order aberrations (HOA) were compared.

Results:

Mean follow-up period was 30 ± 11 months. Preoperatively, spherical equivalent (SE) refractive error was −11.6 ± 3.7, −9.59 ± 1.97, and −12.3 ± 4.8 D in the Artisan, Artiflex and ICL groups, respectively. SE was comparable among the study groups at final follow-up (P = 0.237). Mean astigmatic reduction was 0.31 ± 0.72, 0.45 ± 0.62, and 0.0 ± 0.57 in the Artisan, Artiflex and ICL groups, respectively (P = 0.007). Emmetropia (±1 D) was achieved in 60%, 91.7% and 77.8% of eyes in the Artisan, Artiflex and ICL groups, respectively, the difference was significant between the Artisan and Artiflex groups (P = 0.017). BCVA improvement more than one line occurred in 25%, 19.4% and 38.9% of eyes (P = 0.158); pachymetric changes were minimal with no difference among the three groups (P = 0.754), and mean CEC loss was 10 ± 9%, 9 ± 6% and 9 ± 10% in the Artisan, Artiflex and ICL groups, respectively (P = 0.694). HOAs (P = 0.039), vertical trefoil (P = 0.032) and spherical aberration (P = 0.001) were higher with Artisan group as compared to ICL. Total aberrations (P = 0.028) and spherical aberration (P = 0.001) was also higher with Artisan group as compared to Artiflex.

Conclusion:

Visual and refractive outcomes were comparable with Artisan, Artiflex and ICL. In terms of HOAs and quality of vision, ICL and Artiflex seem to be better choices in highly myopic eyes.

Comparison of the visual outcomes between PRK-MMC and phakic IOL implantation in high myopic patients

PURPOSE

To compare the visual outcomes between PRK-MMC and phakic IOL in patients with more than 8 diopter (D) of myopia.

METHODS

This comparative study was performed on 23 eyes under treatment with Artiflex (group A) and 23 eyes under treatment with PRK-MMC (group B). Artiflex phakic IOL (Ophtec BV) was used in group A, and the VISX STAR S4 Excimer Laser (Abbott) was used for PRK-MMC in group B.

RESULTS

The safety index was 1.11 ± 0.23 and 1.05 ± 0.25 (P = 0.100) and the efficacy index was 1.02 ± 0.11 and 0.98 ± 0.10 (P = 0.266) in group A and B, respectively. At 1 year after surgery, the manifest refraction spherical equivalent was -0.17 ± 1.18 and -0.25 ± 0.18 D in group A and B, respectively (P = 0.471). Mesopic CS showed no significant difference between the two groups in any spatial frequency. Total coma was 0.24 ± 0.17 and 0.67 ± 0.40 μm (P < 0.001), spherical aberration was -0.11 ± 0.11 and 0.41 ± 0.18 μm (P < 0.001), and RMS HOAT was 0.50 ± 0.20 and 0.96 ± 0.45 μm (P<0.001) in group A and B, respectively.

CONCLUSION

Phakic IOL implantation was better than PRK-MMC in the correction of high myopia in terms of visual quality, but the two methods had no difference with regard to visual acuity. Therefore, PRK-MMC can be used when the anterior chamber depth is a limiting factor in the implantation of phakic IOLs.

Intraocular optical quality of phakic intraocular lenses: comparison of angle-supported, iris-fixated, and posterior chamber lenses

PURPOSE

To evaluate internal aberrometric profiles following phakic intraocular lens (PIOL) implantation.

DESIGN

Retrospective and consecutive case series.

METHODS

One hundred and five eyes of 65 patients were included. The optical aberrations were measured with the Topcon KR-1W aberrometer. Comparisons of internal aberrations for different models were made. Comparisons at 4 and 6 mm were made also within the same model for all the lenses. Comparisons regarding the implantation site were also performed: angle-supported (AS) anterior chamber (AC) (n = 47), iris-fixated (IF) (n = 27), and posterior chamber (PC) (n = 31).

RESULTS

Root mean square (RMS) of internal optical higher-order aberrations (HOAs) changed significantly to higher values from 4-6 mm aperture diameter in each PIOL, as should be expected. However, this significant change was not detected in spherical aberration for Kelman Duet (P = .753) and in trefoil for Acrysoft (P = .059). Kelman lens showed significantly lower values of spherical aberration compared to Acrysoft at 4 mm (P = .022) and at 6 mm (P = .042). Acrysoft showed the lowest values at central zone for trefoil (P = .043) and tetrafoil (P = .002) in AC group. In the IF group, Artisan and Artiflex showed similar results for all internal aberrations. In the comparison between Visian Implantable Collamer Lens (ICL; STAAR Surgical Co, Monrovia, California, USA) and phakic refractive lens (PRL), both for posterior chamber, significantly lower values of coma were observed for ICL (P = .033). IF lenses showed clinical evidence, but not significant, of better centering capability than AS lenses (P = .096).

CONCLUSIONS

The study of intraocular aberrations is an adequate method to identify the clinical optical behavior and could help the surgeon to identify the most frequent problems related with each model.

Changes in higher-order aberrations after iris-fixated phakic intraocular lens implantation

PURPOSE

To evaluate surgically induced changes in corneal, internal, and ocular higher-order aberrations (HOAs) after phakic intraocular lens (PIOL) implantation and compare them between two PIOLs with different pupillary diameters.

METHODS

Twenty-three eyes with an Artisan PIOL (Ophtec BV, Groningen, The Netherlands) (Artisan group) and 30 eyes with an Artiflex PIOL (Ophtec BV) (Artiflex group) were retrospectively evaluated. The corneal, internal, and ocular HOAs and refractive data were recorded preoperatively and 6 months postoperatively. The root mean squares (RMSs) of the total HOAs from the third- to sixth-order Zernike coefficients were calculated. The RMSs of the third- and fourth-order coefficients represented coma-like aberrations (S3) and spherical-like aberrations (S4), respectively. The main outcome measures were the differences in the parameters among the groups with different pupillary diameters.

RESULTS

The mean postoperative spherical equivalents decreased from -11.84 ± 4.90 to -0.16 ± 0.40 diopters and -9.78 ± 3.20 to -0.09 ± 0.26 diopters in the Artisan and Artiflex groups, respectively. With the 4- and 5-mm pupillary diameters, the postoperative internal and ocular spherical aberrations (Z4(0)) were significantly lower in the Artiflex group than in the Artisan group (4 mm, P = .002, .024; 5 mm, P = .004, .022, respectively). With the 6-mm pupillary diameter, there were no significant postoperative differences in any parameter measured between groups; both groups had positive spherical aberration values.

CONCLUSIONS

The postoperative ocular spherical aberrations were positive after Artisan and Artiflex implantation. The postoperative ocular spherical aberration was greater in the Artisan group, possibly due to differences in the SAs of both PIOLs.

Visian implantable contact lens versus AcrySof Cachet phakic intraocular lenses: comparison of aberrmetric profiles

Purpose

To evaluate the in vivo aberrometric performance of two phakic intraocular lenses (PIOLs); the Visian implantable contact lens (ICL) and the AcrySof Cachet PIOL.

Methods

Thirty eight eyes from 29 patients with an age range of 23–32 years and more than 9 D of myopia were divided into two groups; one group of 20 eyes received a Visian ICL model V4c, another group of 18 eyes received an AcrySof Cachet PIOL. Total higher order aberrations (HOAs) root mean square, total coma, and total spherical aberrations were recorded pre and 6 weeks postoperatively to evaluate and compare the aberrometric performance of the Visian ICL and the AcrySof Cachet PIOL implanted in highly myopic patients.

Results

Preoperatively, there were no significant differences in any studied parameters, except for preoperative spherical equivalent. Postoperatively, there were no statistically significant differences in the induction of HOAs between both PIOLs. The reduction in spherical aberrations was statistically significant in each group as well as in all study patients.

Conclusion

Both AcrySof Cachet PIOL and ICLs are effective phakic implants to correct high refractive errors. They both induce small amounts of negative spherical aberration that do not affect the total HOAs, yet reduce the positive ocular spherical aberration. This result is expected to improve the quality of vision in such patients.

Optical quality comparison of conventional and hole-visian implantable collamer lens at different degrees of decentering

PURPOSE

To compare the optical quality of implantable Collamer lens (ICL) with and without central hole (Hole ICL and conventional ICL) at different degrees of decentering.

DESIGN

Experimental laboratory investigation.

METHODS

Wavefront aberrations of the -3, -6, and -12 diopter (D) V4b and -3, -6, and -12 D V4c ICLs were measured in 3 conditions-centered and decentered 0.3 and 0.6 mm-at 3-mm and 4.5-mm pupils. The root mean square of total higher order aberrations, trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, point spread function and simulated retinal images of ICLs were calculated from the wavefront aberrations for each ICL and all conditions of decentering at 4.5-mm pupil.

RESULTS

No statistically significant differences in any Zernike coefficient terms evaluated were found between conventional and Hole ICLs for any ICL powers and pupils evaluated (P > .05). We could not appreciate differences in the point spread function images and in simulated retinal images. Regarding the effect of the ICL decentration, coma aberration increased significantly with ICL decentration (P < .05), although these differences were not visible in the point spread function images and simulated retinal images. The ICL decentration was affected in the same manner on the conventional and Hole ICLs.

CONCLUSIONS

The outcomes showed good and comparable optical quality of the conventional and Hole ICLs for all ICL powers evaluated. Despite that coma aberration increased with ICL decentering, these values were clinically negligible and did not have a significant effect on the simulated visual performance.

Preliminary in vivo positional analysis of a posterior chamber phakic intraocular lens by optical coherence tomography and its correlation with clinical outcomes

Purpose

To analyze by spectral-domain optical coherence tomography the anatomical relationship of a specific type of posterior chamber phakic intraocular lens (pIOL) implanted in cases of high to moderate myopia with the adjacent intraocular structures and to correlate it with clinical outcomes.

Methods

Prospective observational case series including 18 eyes with high to moderate myopia (spherical equivalent between −5.88 and −15.75 D) of 9 patients (age range, 29–49 years) undergoing bilateral Phakic Refractive Lens (PRL, Zeiss) implantation. Postoperative visual acuity, refraction, contrast sensitivity (CS), and ocular higher order aberrations (HOA) were evaluated. Furthermore, the in vivo position of the PRL was analyzed by means of spectral domain optical coherence tomography (3D OCT-1000, Topcon). Central (CENV), temporal (TEMV) and nasal vault (NASV) were measured. Correlation of these anatomical parameters with clinical data was also investigated. Mean follow-up was 47 ± 25 months.

Results

A statistically significant visual and refractive improvement (p < 0.01) was found postoperatively. Mean postoperative CENV, NASV, and TEMV were 157.88 ± 69.93 μm, 168.29 ± 65.02 μm, and 188.59 ± 55.99 μm, respectively. Significant difference was found between NASV and TEMV (p = 0.01). No significant correlations were found between ocular aberrometric and anatomical parameters (p ≥ 0.12). CENV, NASV and TEMV correlated significantly with 6-cycles per degree (cpd) photopic CS as well as with 18-cpd low mesopic CS (r ≥ 0.57, p ≤ 0.04). Furthermore, NASV also correlated significantly with preoperative anterior chamber depth (r = −0.65, p = 0.01).

Conclusions

This posterior chamber pIOL shows a trend to nasal position, with potential impact on refractive and visual outcomes, particularly in eyes with deep anterior chambers.

AcrySof cachet phakic intraocular lens in myopic patients: visual performance, wavefront error, and lens position

PURPOSE

To evaluate visual and aberrometric outcomes and position of the AcrySof Cachet (Alcon Laboratories Inc) angle-supported phakic intraocular lens (PIOL) for correction of myopia in adults.

METHODS

This prospective study included 36 consecutive eyes with moderate to high myopia in which an AcrySof Cachet PIOL was implanted to minimize refractive error. Follow-up was up to 1 year.

RESULTS

Mean manifest spherical equivalent refraction reduced significantly from -14.90 ± 0.90 diopters (D) to -0.29 ± 0.30 D at 1 month and remained stable at 1 year (P<.001). Mean uncorrected distance visual acuity was >0.1 logMAR (20/20 Snellen) in 56% of patients and >0.3 logMAR (20/25 Snellen) in 100% of patients. Corrected distance visual acuity was >0.1 logMAR (20/20 Snellen) in 78% of patients and >0.3 logMAR (20/25 Snellen) in 100% of patients. Mean endothelium-PIOL distance and mean PIOL-crystalline distance were within recommended values at all postoperative evaluations. Statistically significant variations for these variables were not observed. Anterior chamber depth, safety center distance, and vault center distance showed significant reduction after accommodation (P<.01). Anterior chamber depth and safety center distance significantly increased after pupil dilation (P<.01). Mean percentage of endothelial cell loss was 4.04% at 1 year. The root-mean-square of total higher order aberrations and spherical, coma, and trefoil aberrations did not change significantly from pre- to postoperatively.

CONCLUSIONS

The AcrySof Cachet PIOL was effective in the correction of moderate to high myopia and provided excellent visual performance with no modification of physiologic ocular wavefront error. Adequate distance from the cornea and crystalline lens was maintained with no significant change during follow-up and under different environmental conditions.

Higher-order aberration changes after Implantable Collamer Lens implantation for myopia

PURPOSE

To investigate the changes in higher-order aberrations (HOAs) induced by implantation of Implantable Collamer Lenses (STAAR Surgical) and to explain them in relation to the surgical incision and optical properties.

DESIGN

Prospective, observational case study.

METHODS

This study included 56 eyes undergoing Implantable Collamer Lens insertion for myopic correction. The corneal incision size was determined according to the amount of astigmatism. HOAs were measured before surgery and 3 months after surgery in 25 eyes having small superior incision (<3.2 mm) surgery and in 31 eyes with large superior incision (3.2 to 4.5 mm) surgery. Changes in spherical aberration, coma, trefoil, and total HOAs (third to sixth order) were analyzed. Laboratory measurements of aberration profiles of Implantable Collamer Lenses with different optical powers were performed to validate clinical measurements.

RESULTS

In the small-incision group, trefoil (Z(3)(-3)) and spherical aberration changed significantly (P=.004). In the large-incision group, in addition to trefoil and spherical aberration, total HOA changed significantly (mean change, 0.13 ± 0.17; P=.001). Significant correlations were observed among the incision size, the astigmatism induced, and the trefoil induced. Induced trefoil showed a predominant pattern at the orientation of the incision meridian. Optical measurement of aberrations of the Implantable Collamer Lenses confirmed the postoperative negative spherical aberration.

CONCLUSIONS

HOA changes after Implantable Collamer Lens insertion were increased trefoil and induced negative spherical aberration. These changes may be explained by the effect of the corneal incision and the negative spherical aberration in the Implantable Collamer Lens, respectively.

Pediatric phakic intraocular lens surgery: review of clinical studies

PURPOSE OF REVIEW

To report on the accumulating peer-reviewed data of phakic intraocular lens (pIOL) implantation in the pediatric population. I evaluate and compare the published peer-reviewed articles for the reported efficacy and complications of phakic intraocular lens implantations in children for correction of clinically significant high refractive errors.

RECENT FINDINGS

Multiple studies have shown the relevancy and effectiveness of pIOL implantation as an alternative surgical management for highly significant pediatric ametropia in selective patients who are noncompliant with medical treatment.

SUMMARY

In the management of clinically significant severe pediatric ametropic and/or anisometropic myopia or hyperopia and in the event of nonadherence to traditional medical treatment, phakic anterior chamber IOL implantation is currently considered an effective modality of treatment. Long-term follow-up of pediatric patients following pIOL implantation is necessary. Future clinical trials should focus on children of various age groups to assess the variables of visual acuity gain or loss, stereopsis, contrast sensitivity, high-order aberrations, corneal physiology, and long-term complications to accurately and properly address the safety and efficacy of the type of and the best time for pIOL implantation in treatment and/or prevention of amblyopia in children.