Higher-order aberrations after iris-fixated foldable phakic intraocular lens implantation and wavefront-guided photorefractive keratectomy for the correction of myopia

Wavefront-Guided Photorefractive Keratectomy with the Use of a New Hartmann-Shack Aberrometer in Patients with Myopia and Compound Myopic Astigmatism

Purpose. To assess refractive and visual outcomes and patient satisfaction of wavefront-guided photorefractive keratectomy (PRK) in eyes with myopia and compound myopic astigmatism, with the ablation profile derived from a new Hartmann-Shack aberrometer. Methods. In this retrospective study, 662 eyes that underwent wavefront-guided PRK with a treatment profile derived from a new generation Hartmann-Shack aberrometer (iDesign aberrometer, Abbott Medical Optics, Inc., Santa Ana, CA) were analyzed. The preoperative manifest sphere ranged from −0.25 to −10.75 D, and preoperative manifest cylinder was between 0.00 and −5.25 D. Refractive and visual outcomes, vector analysis of the change in refractive cylinder, and patient satisfaction were evaluated. Results. At 3 months, 91.1% of eyes had manifest spherical equivalent within 0.50 D. The percentage of eyes achieving uncorrected distance visual acuity 20/20 or better was 89.4% monocularly and 96.5% binocularly. The mean correction ratio of refractive cylinder was 1.02 ± 0.43, and the mean error of angle was 0.00 ± 14.86° at 3 months postoperatively. Self-reported scores for optical side effects, such as starburst, glare, halo, ghosting, and double vision, were low. Conclusion. The use of a new Hartmann-Shack aberrometer for wavefront-guided photorefractive keratectomy resulted in high predictability, efficacy, and patient satisfaction.

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.

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.

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.