Funktionelle Ergebnisse nach Korrektur der Presbyopie mittels bilateraler intrastromaler Femtosekundenlaserbehandlung

Refractive Outcomes of Cataract Surgery in Patients With Intrastromal Femtosecond Laser Treatment of Presbyopia (INTRACOR)

PURPOSE

To evaluate the outcomes of cataract surgery with intraocular lens (IOL) implantation in patients who underwent intrastromal femtosecond laser treatment of presbyopia (INTRACOR).

METHODS

This was an interventional case series of 8 patients (10 eyes) who presented for cataract surgery 6.1 ± 3.2 years (mean ± standard deviation [SD]) after INTRACOR (Technolas Perfect Vision GmbH) treatment. A monofocal IOL was implanted in 9 eyes (7 patients) and a small-aperture IOL was implanted in 1 eye. The IOL power was calculated without adjustments using biometry obtained after the INTRACOR treatment. For additional calculations, keratometry obtained before the INTRACOR treatment was used. Postoperative examinations included visual acuity testing, manifest refraction, defocus curve, ocular biometry, corneal tomography, aberrometry, anterior segment optical coherence tomography, and slit-lamp examination.

RESULTS

After the cataract surgery, the mean ± SD uncorrected distance visual acuity was 0.37 ± 0.17 logMAR, the corrected distance visual acuity was 0.10 ± 0.10 logMAR, and the manifest refraction spherical equivalent, adjusted to infinity, was +0.39 ± 0.63 diopters (D). Intermediate and near visual acuity, both uncorrected and distance-corrected, and distance-corrected defocus curves varied considerably among patients. Using biometry performed after INTRACOR, the traditional IOL power calculation formulas produced hyperopic outcomes, with the mean ± SD prediction error ranging from +0.72 ± 0.34 to +0.96 ± 0.41 D. Although the mean ± SD prediction error decreased (range: -0.34 ± 0.56 to -0.15 ± 0.53 D) when using keratometry obtained before INTRACOR, the accuracy remained low due to high variability.

CONCLUSIONS

In patients with cataract who had previous INTRACOR treatment, IOL power calculation could be inaccurate, with a tendency toward hyperopic outcomes. These results require confirmation in more extensive studies. [J Refract Surg. 2023;39(10):676-682.].

Presbyopia correction after previous Intracor treatment: Combined implantation of a small-aperture and a non-diffractive extended-depth-of-focus lens

PURPOSE

We present the case of implantation of two different Extended depth of focus intraocular lenses (EDoF IOLs) in a patient with a history of unilateral intrastromal femtosecond laser treatment for presbyopia correction (Intracor).

OBSERVATIONS

The patient reported decreasing visual acuity at near distance and increasing spectacle dependence. Ten years earlier, he had Intracor treatment for presbyopia correction in his left eye. Corrected distance visual acuity (CDVA) was 0.08 logMAR for the right eye and 0.16 logMAR for the left eye. Apart from dysfunctional lens syndrome, the examination results were unremarkable. Phacoemulsification and subsequent IOL implantation was performed in both eyes. The left eye was implanted with an IC-8 (AcuFocus, Irvine, CA, USA), whereas the fellow eye was implanted with an AcrySof IQ Vivity IOL (Alcon, Fort Worth, TX, USA). Postoperatively, CDVA improved to 0.02 and 0.04 logMAR for the right and left eye. Uncorrected intermediate visual acuity (UIVA) was 0.24 logMAR for the right eye and -0.04 logMAR for the left eye, binocular UIVA was -0.04 logMAR. The patient reported a low level of photic phenomena and spectacle independence for far and intermediate distance.

CONCLUSIONS AND IMPORTANCE

Combined implantation of a non-diffractive and a small-aperture EDoF lens after previous unilateral Intracor treatment could successfully improve visual acuity at far and intermediate distance.

Flap Thickness and the Risk of Complications in Mechanical Microkeratome and Femtosecond Laser In Situ Keratomileusis: A Literature Review and Statistical Analysis

INTRODUCTION

A recent Cochrane review found no difference in visual acuity outcomes between femtosecond-assisted laser in situ keratomileusis (LASIK) and LASIK using mechanical microkeratomes (MMKs). This study compares the flap thickness and risk of complications related to flap creation using femtosecond lasers and MMKs.

METHODS

PubMed and the Web of Science are used to search the medical literature. An extensive search is performed to identify the flap thickness and complications of LASIK as reported up to 15 July 2021. The following keywords are used in various combinations: Corneal flap, femtosecond laser, laser in situ keratomileusis, laser-assisted in situ keratomileusis, LASIK, mechanical microkeratome.

RESULTS

After removing duplicates and irrelevant studies, 122 articles were included for review. Pooled differences for intended vs. postoperative flap thickness using MMKs and femtosecond laser were -4.07 μm (95% CI: -19.55, 3.24 μm) in studies on the MMK and 5.43 μm (95% CI: 2.30, 7.84 μm; p < 0.001), respectively. After removing the studies evaluating outcomes of the old generation Hansatome MMKs (which had a significantly greater variation of flap thickness), the pooled difference for newer MMKs was 4.97 μm (95% CI: 0.35, 9.58 μm; p < 0.001), but the results still favored the femtosecond laser. Uncommon and mild complications unique for the femtosecond LASIK are epithelial gas breakthrough, opaque bubble layer, transient light sensitivity syndrome, and rainbow glare. A single study reported a very low, but stastically different risk of postoperative flap slippage (0.033% for MMK LASIK, and 0.003% for femtosecond LASIK, respectively).

CONCLUSION

In both manual microkeratome and femtosecond LASIK, intra- and postoperative complications were uncommon. The evidence of the superiority of one technique in terms of complications over another cannot be indisputably stated.

Assessment of contrast sensitivity loss after intrastromal femtosecond laser and LASIK procedure

AIM

To assess the loss of contrast sensitivity (CS) function for INTRACOR or intrastromal femtosecond laser presbyopia procedure to conventional LASIK procedures.

METHODS

Patients were recruited from a refractive surgery center for either INTRACOR or conventional LASIK. INTRACOR was performed on 8 eyes and LASIK was performed for 40 eyes in an overlapping period. Pre-operative evaluation and post-operative follow up for up to three months was done. Drops of CS in 4 spatial frequency (3 cpd, 6 cpd, 12 cpd and 18 cpd) right before and 3mo after the surgery were compared by Wilcoxon signed ranks test.

RESULTS

For INTRACOR, CS threshold showed significant drop at both glare and non-glare condition, the drop was seen in all 4 spatial frequency. The averaged loss over the 4 spatial frequencies 3mo after surgery was 1.18 for non-glare and 0.71 for glare. For LASIK the CS threshold drop was most significant in 12 cpd for glare.

CONCLUSION

INTRACOR procedure produces a gain of near vision for presbyopia patients but also introduces a high lost of contrast sensitivity plus worsen of vision quality. Pre-surgical patient selection and advise should be given with specific regards to night driving and glare conditions.

[Comparison of two different surgical treatments of presbyopia for hyperopic patients over 55 years old: Presbylasik (Supracor) and Prelex (presbyopic lens exchange)]

INTRODUCTION

The management of presbyopic patients is a medical, surgical and economic issue. We wondered which procedure, whether a Presbylasik technique called Regular Supracor or the intraocular surgery of clear lens replacement by a trifocal diffractive lens (presbyopic lens exchange [Prelex]), provided the best results (in visual acuity and satisfaction) for our hyperopic and presbyopic patients between 55 and 70. The aim of this study was to compare the safety and efficacy of the two techniques (at one week and three months) and to assess patients' quality of life.

METHODS

This study is a retrospective monocentric clinical trial conducted between June 2011 and March 2014, on 21 hyperopic presbyopic patients (mean age 60.9 years), in the "hôpital d'instruction des armées-Percy" (Clamart); 13 patients underwent the corneal treatment of Presbylasik (with the Intralase FS60 femtosecond laser [AMO, USA] and the Technolas 217P excimer laser [Technolas Perfect Vision, GmbH] following the Zyoptix Tissue-Saving algorithm adjusted with a nomogram and the Regular Supracor mode), and 8 patients underwent clear lens extraction (Prelex), through bimanual phacoemulsification and implantation of diffractive trifocal intraocular lenses (Finevision Micro F, PhysIOL(*)).

RESULTS

Mean uncorrected binocular distance and near vision visual acuity in the Supracor group were respectively 0.03 (-0.2-0.1) LogMar and 0.23 (0.06-0.36) one week postoperatively and 0.031 (-0.2-0.1) and 0,166 (0.06-0.36) three months postoperatively. In the Prelex group, the mean uncorrected one week binocular VA was 0.025 (0-0.1) for distance vision and 0.165 (0.06-0.18) for near distance and the three months visual acuity was 0 (-0.1-0.1) and 0.105 (0.06-0.18) for distance and near vision. All Prelex patients were spectacle-free at all distances, whereas 4 Supracor patients required spectacles for near vision postoperatively. Seven of 11 patients in the Supracor group and 100% of the Prelex patients were completely satisfied. Both groups experienced halos, but patients reported more halos in the Prelex group (75%). One eye required intraocular lens exchange and four eyes (16.7%) required a new corneal procedure in the Supracor group.

CONCLUSION

Both surgeries are safe and effective modalities in the management of hyperopic and presbyopic patients. However, the Prelex procedure seems to be more appropriate for patients over 55 years of age.