Femtosecond-assisted Laser Research Articles

Effect of mesopic pupil size on aberrometric outcomes after femtolaser-assisted intracorneal ring implantation in keratoconus

Purpose: This study aimed to evaluate the effect of mesopic pupil size on corneal high-order aberrations in keratoconic eyes implanted with femtosecond laser-assisted intracorneal ring segments (ICRS) implantation procedure. Design: The study design involves a retrospective, consecutive case series. Patients and Methods: A total of 160 consecutive eyes of 133 patients with the diagnosis of keratoconus (93 eyes with keratoconus Grade 2 and 67 with keratoconus Grade 3) were included in the study. Keraring (Mediphacos, Belo Horizonte, Brazil) implantations were performed using femtosecond-assisted laser in Sohag Refractive Center, Sohag, Egypt, between September 2015 and September 2017. Pupil size and anterior corneal aberrations were measured by Scheimpflug placido topography (Sirius, CSO, Italy). Results: There were statistically significant changes between corneal aberrations preoperatively and postoperatively in both groups. Mesopic pupil size had no significant correlation with all corneal aberrations. Conclusion: Mesopic pupil size did not prove to be affecting corneal aberrations after femtosecond laser-assisted ICRS implantation for keratoconus.

Posterior capsular complication rates with femtosecond laser-assisted cataract surgery: a consecutive comparative cohort and literature review.

PurposeThe aim of the study was to determine whether femtosecond-assisted laser cataract surgery (FLACS) reduces the posterior capsular complication (PCC) rate compared to manual cataract surgery when performed by an experienced surgeon.Patients and methodsWe reviewed 2,021 consecutive FLACS procedures between 1 June 2012 and 30 August 2017. All cases of posterior capsular rupture (PCR) with or without vitreous prolapse or zonular dialysis (ZD) that prevented an in-the-bag placement of the intraocular lens were included. Risk factors were noted and outcomes documented.ResultsSix eyes of 2,021 (0.3%) who underwent FLACS had either a PCR or ZD. One eye (0.25%) of 403 eyes that had manual cataract surgery had a PCR. There was no significant difference in outcomes. Risk factors included advanced age, dense nuclei, pseudoexfoliation and small pupil. Only a single case in the FLACS series may have been directly attributed to the FLACS procedure.ConclusionThis study provides evidence that there is no significant difference in the PCC rate between FLACS and manual cataract surgery in the hand of an experienced surgeon who performs >350 cases annually. This low rate of complications may be achieved by less experienced surgeons adopting FLACS.

Observation on the efficacy of aberration elimination program in femtosecond assisted laser in situ keratomileusis for the correction of myopia and myopic astigmatism

Objective To observe the efficacy of aberration elimination program in femtosecond assisted situ keratomileusis (FS-LASIK)for the correction of myopia and myopic astigmatism. Methods A prospective study. From Dec. 2013 to Aug. 2014, 76 eyes of 76 cases with myopia and myopic astigmatism received aberration elimination program FS-LASIK .The right eye was the object of study.There were 37 eyes of low to moderate myopia and myopic astigmatism(<-6.0D) and 39 eyes of high myopia and myopic astigmatism(≥-6.0D). The Optikon 2000 corneal wavefront aberration analyzer was used to examine the corneal higher-order aberrations before and 3 months after surgery. The corneal higher-order aberrations included spab, coma and total higher-order aberrations. Results The difference of spherical aberration, coma and total higher- order aberrations were not statistically significant between before and 3 months after surgery(t=1.999, 1.508, 1.435; P=0.053, 0.080, 0.075). The difference of corneal higher-order aberration of patients with low to moderate myopia and myopic astigmatism were not statistically significant between before and 3 months after surgery(t=1.530, 1.774, 2.053; P=0.120, 0.080, 0.052). The difference of the corneal higher-order aberrations of patients with high myopia and myopic astigmatism between before and 3 months after surgery were statistically significant (t=3.408, 5.372, 2.829; P=0.005, 0.000, 0.005). The variational ratio and multiple of higher -order aberrations in low to moderate myopia and myopic astigmatism were less than that in high myopia and myopic astigmatism. Conclusion The aberration elimination program can effectively reduce the higher- order aberrations especially in low to moderate myopic astigmatism after FS-LASIK. Key words: Aberration, higher-order; Femtosecond assisted laser in situ keratomileusis; Program aberration elimination

Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction.

Purpose To estimate the treatment effectiveness of femtosecond-assisted laser in situ keratomileusis (FS-LASIK) and Toric implantable collamer lens (Toric ICL) for moderate and high astigmatism via vector analysis. Materials and Methods The study involved 44 eyes from 44 patients who had a preoperative refractive cylinder ≥1.0 diopters (D) and underwent bilateral FS-LASIK or Toric ICL surgery. The examinations included corrected distance visual acuity measurement and subjective refraction before and 3 months after surgery. The astigmatic changes were estimated using vector analysis. Results No statistically significant differences were found in cylindrical refraction and percentage of spherical equivalent within 0 D, ±0.50 D, ±1.00 D, and ±1.50 D between the FS-LASIK and Toric ICL groups at 3 months after surgery. The parameters of the vector analysis included intended refractive correction, surgically induced refractive correction, error vector, correction ratio, error ratio, error of magnitude, and error of angle, with no significant differences between the groups. However, error ratio the of the off-axis correction in the FS-LASIK and Toric ICL groups was 4.11 ± 3.02 and 8.11 ± 3.82, respectively, and the difference was significant (t = −2.46, p=0.02). Conclusion Both FS-LASIK and Toric ICL were effective for correcting moderate and high astigmatism, although Toric ICL might produce a larger error of angle than FS-LASIK when an off-axis correction occurs.

Assessment of refractive outcome of femtosecond-assisted LASIK for hyperopia correction.

IntroductionLaser vision correction for hyperopia is challenging. The purpose of the study was to assess the refractive outcomes of femtosecond-assisted laser in situ keratomileusis (LASIK) for hyperopic correction using wavefront-optimized ablation profiles.MethodsThis retrospective case series study included 20 Egyptian patients (40 eyes) with hyperopia or hyperopic astigmatism with a mean manifest refraction spherical equivalent (MRSE) of +2.55D±1.17 (range from +1.00 to +6.00) who had uneventful femtosecond-a assisted LASIK with wavefront-optimized aspheric ablation profile using refractive surgery suite (WaveLight FS200 Femtosecond Laser and WaveLight EX500 Excimer Laser) performed in the Research Institute of Ophthalmology and International Eye Hospital, Giza, Egypt. Statistical analysis was done using Microsoft Excel (Microsoft Corporation, Seattle, WA, USA).ResultsThe procedure significantly reduced the MRSE and cylinder post-operatively (95% were ± 0.50D and 100% ± 1.00 D), with stability of refraction and UDVA over the follow-up period (up to 12 months) after surgery. No eye lost any line of the CDVA, which reflects the excellent safety profile of the procedure; on the other hand, one eye (5%) gained one line and one eye (5%) even gained two lines. There were no significant complications during the procedure.ConclusionsFemtosecond-assisted laser in situ keratomileusis for hyperopia showed predictable, effective, and safe refractive outcomes that were stable through 12 months. Longer follow-up period is required to detect any further regression

Myopia correction with transepithelial photorefractive keratectomy versus femtosecond−assisted laser in situ keratomileusis: One-year case-matched analysis

To compare the postoperative clinical outcomes of single-step transepithelial photorefractive keratectomy (PRK) and femtosecond-assisted laser in situ keratomileusis (LASIK). Bergman Clinics, Utrecht, the Netherlands. Retrospective case series. The eyes of consecutive patients who had transepithelial PRK were retrospectively compared with the same number of case-matched eyes (based on the preoperative refractive components) treated with femtosecond-assisted LASIK. The clinical outcomes evaluated were predictability, refractive outcomes, and visual acuity. The Student t test and chi-square test were used for statistical analysis. The study compared 98 patients (196 eyes) who had transepithelial PRK with the outcomes in 196 case-matched eyes that had femtosecond-assisted LASIK. All patients completed the 1-year follow-up. At 1year, 130 eyes (66%) in the transepithelial PRK group and 91 eyes (46%) in the femtosecond-assisted LASIK group achieved an uncorrected distance visual acuity of -0.1 logMAR or better (P<.005), 4 eyes (2%) in the transepithelial PRK and 2 eyes (1%) in the femtosecond-assisted LASIK group lost 2 lines of corrected distance visual acuity (P=.04), and 163 eyes (83%) in the transepithelial PRK and 167 eyes (85%) in the femtosecond-assisted LASIK group were within ±0.50 diopter (D) of emmetropia. The postoperative mean spherical equivalent was +0.11 D ± 0.56 (SD) for transepithelial PRK and -0.09±0.46 D for femtosecond-assisted LASIK (P<.0001). Transepithelial PRK outcomes 1year postoperatively were equivalent to those of femtosecond-assisted LASIK. Transepithelial PRK was efficacious and safe; however, the procedure had a longer recovery time than the femtosecond-assisted LASIK. Mr. Ewering and Dr. Arba-Mosquera are employees of Schwind eye-tech-solutions GmbH and Co. KG. Dr. Luger has no financial or proprietary interest in any material or method mentioned.

Femtosecond-assisted laser in situ keratomileusis for consecutive hyperopia after radial keratotomy

To evaluate femtosecond-assisted laser in situ keratomileusis (LASIK) for the treatment of hyperopic shift after radial keratotomy (RK). Private practice, Siena, Italy. Prospective case series. Eyes with a spherical equivalent (SE) of +1.0 diopters (D) to +4.0 D after RK with 6 or 8 incisions had LASIK. The flap (nominal thickness 130 μm) was created with a femtosecond laser (LDV Z2); the refractive ablation was performed with an excimer laser (217P). The flap was dissected in a centrifugal fashion along previous RK cuts. Eighteen eyes of 10 patients were treated. Preoperatively, the mean defocus equivalent was 3.13 diopters (D) ± 0.71 (SD); the corrected distance visual acuity (CDVA) was 0.09 ± 0.06 logMAR. At 9 months, the mean defocus equivalent was 0.51 ± 0.47 D (P < .05), with 13 eyes (72%) having 0.50 D or less of defocus equivalent and 16 eyes (89%) having 1.0 D or less of defocus equivalent. The mean CDVA was 0.04 ± 0.06 logMAR (P < .05). No lines of logMAR CDVA were lost. The mean uncorrected distance visual acuity was 0.11 ± 0.10 logMAR. The safety index was 1.11; the efficacy index was 0.97. No retreatments were performed. Flap complications were limited to an RK incision opening larger than 2 mm in 3 eyes and 1 case of a small, self-limiting epithelial ingrowth. Laser in situ keratomileusis with a low-energy femtosecond laser was a safe and effective approach to treat post-RK hyperopia, causing no relevant inflammation. Neither author has a financial or proprietary interest in any material or method mentioned.

Vector analysis of astigmatic correction after small-incision lenticule extraction and femtosecond-assisted LASIK for low to moderate myopic astigmatism

AimTo compare astigmatic correction between femtosecond-assisted laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE).MethodsA total of 111 patients were included in this prospective study. Fifty-seven eyes were treated...

Management of pain with diclofenac after femtosecond-assisted laser in situ keratomileusis

To evaluate the safety and efficacy of topical diclofenac sodium 0.1% after femtosecond laser-assisted laser in situ keratomileusis (LASIK). W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA. Clinical trial. Pain was assessed in patients treated with topical diclofenac sodium 0.1% or artificial tears immediately after LASIK using a numeric pain scale and a combined picture-numeric pain scale 0, 2, 4, 12, and 24 hours postoperatively. Visual outcomes and complications were noted up to 24 hours. The study enrolled 100 eyes of 50 patients. Patients treated with diclofenac 0.1% reported less pain than the control group on both pain scales 2, 4, 12, and 24 hours after surgery, with the maximum benefit at 4 hours (P=.02). Fewer patients in the diclofenac group (76.0%) than in the control group (91.3%) used oral pain and/or anxiolytic medications during the first 24 hours after surgery (P=.25). Ninety-eight eyes had an uncorrected distance visual acuity of 20/40 or better. Mild peripheral diffuse lamellar keratitis accounted for the majority of perioperative complications (n = 15). Pain after femtosecond laser-assisted LASIK was mild and was reduced with a single dose of topical diclofenac sodium 0.1% given immediately after surgery.