Small-Incision Lenticule Extraction (SMILE) for the Correction of Myopia with Astigmatism: Outcomes of the United States Food and Drug Administration Premarket Approval Clinical Trial.

To present outcomes of the United States Food and Drug Administration premarket approval clinical trial of small-incision lenticule extraction (SMILE) for the correction of myopia and astigmatism. Prospective, multicenter clinical trial. The study included 357 eyes of 357 patients treated with SMILE (50 for myopia and 307 for myopia with astigmatism). Preoperative sphere ranged between -1.00 and -10.00 diopters (D), with manifest spherical equivalent (MSE) of up to -11.50 D and refractive cylinder of up to -3.00 D. -Participants were followed up for 12 months. Corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA), stability of the manifest refraction, and vector analysis of refractive cylinder are presented for the 307 eyes treated for myopia with astigmatism. Adverse events (AEs) are presented for all 357 eyes. Corrected distance visual acuity, uncorrected distance visual acuity, manifest refraction, astigmatic outcomes, and adverse events. Of the 307 astigmatic eyes enrolled in the study, 304 were treated successfully. In 3 eyes, the procedure was aborted because of intraoperative suction loss. The mean MSE reduced from -5.39±2.30 D at baseline to -0.01±0.24 D at 12 months. Of all eyes, 95.3% were within 0.50 D of emmetropia at 12 months. The percentage of eyes with UDVA of 20/20 or better was 89.0%. No loss of 2 or more lines of CDVA was observed at the 12-month visit. The refractive cylinder reduced from -1.53±0.70 D at baseline to -0.18±0.31 D at 12 months. The mean correction ratio of refractive cylinder was 0.96±0.16 and a slight undercorrection was apparent for higher attempted corrections of astigmatism. Three intraoperative AEs associated with difficult lenticule removal and resultant cap tear occurred, and all resolved without sequelae at postoperative day 1. During the postoperative period, 8 AEs were recorded, but none of them had significant consequences. Small-incision lenticule extraction for the treatment of myopia and astigmatism was safe and effective, and the reported AEs had no significant impact on visual acuity. Slight undercorrection of refractive cylinder requires further attention.

Dishler JG ，Slade S ，Seifert S ，Schallhorn SC ... -  《-》

Safety and complications of more than 1500 small-incision lenticule extraction procedures.

To evaluate the safety and complications of small-incision lenticule extraction (SMILE). Clinical control cohort study. A total of 922 healthy patients (1800 eyes) who were treated for myopia or myopic astigmatism between January 2011 and March 2013 at the Department of Ophthalmology, Aarhus, Denmark. Patients received a full preoperative examination and were treated with SMILE in both eyes and followed for 3 months (1574 eyes). Patients with complications, including loss of corrected distance visual acuity (CDVA) or dissatisfaction, were offered a late reexamination. Surgical complications and CDVA. Mean preoperative spherical equivalent refraction was -7.25±1.84 diopters (D). Average postoperative refraction was -0.28±0.52 D, and mean error of treatment was -0.15±0.50 D. By 3 months, 86% (1346 eyes) had unchanged or improved CDVA. A loss of 2 or more lines was observed in 1.5% of eyes; however, at a late follow-up visit (average, 18 months), CDVA was within 1 line of the preoperative level in all eyes. Perioperative complications included epithelial abrasions (6%), small tears at the incision (1.8%), and difficult lenticule extraction (1.9%). The cap was perforated in 4 eyes, and a major tear occurred in 1 eye; however, none of these patients had late visual symptoms. In 0.8% (14 eyes), suction was lost during surgery. Re-treatment was successful in 13 eyes, whereas 1 eye had ghost images and was re-treated with topography-guided photorefractive keratectomy (PRK). Postoperative complications included trace haze (8%), epithelial dryness on day 1 (5%), interface inflammation secondary to central abrasion (0.3%), and minor interface infiltrates (0.3%); these complications had an impact on CDVA at 3 months in only 1 case. Irregular corneal topography occurred in 1.0% of eyes, resulting in reduced 3-month CDVA (12 eyes) or ghost images (6 eyes). Topography-guided PRK was performed in 4 eyes, with improvement in 3 cases. Satisfaction was high, with only 2 patients dissatisfied at their latest visit because of blurred vision or residual astigmatism. Overall, SMILE had acceptable safety. Although 1.5% of eyes had reduced CDVA by 3 months, visual acuity was restored in the long term. Likewise, patient satisfaction was high.

Ivarsen A ，Asp S ，Hjortdal J 《-》

Vector analysis of high (≥3 diopters) astigmatism correction using small-incision lenticule extraction and laser in situ keratomileusis.

To compare the astigmatic correction in high myopic astigmatism between small-incision lenticule extraction and laser in situ keratomileusis (LASIK) using vector analysis. Hong Kong Laser Eye Center, Hong Kong. Retrospective case series. Patients who had correction of myopic astigmatism of 3.0 diopters (D) or more and had either small-incision lenticule extraction or femtosecond laser-assisted LASIK were included. Only the left eye was included for analysis. Visual and refractive results were presented and compared between groups. The study comprised 105 patients (40 eyes in the small-incision lenticule extraction group and 65 eyes in the femtosecond laser-assisted LASIK group.) The mean preoperative manifest cylinder was -3.42 D ± 0.55 (SD) in the small-incision lenticule extraction group and -3.47 ± 0.49 D in the LASIK group (P = .655). At 3 months, there was no significant between-group difference in uncorrected distance visual acuity (P = .915) and manifest spherical equivalent (P = .145). Ninety percent and 95.4% of eyes were within ± 0.5 D of the attempted cylindrical correction for the small-incision lenticule extraction and LASIK group, respectively (P = .423). Vector analysis showed comparable target-induced astigmatism (P = .709), surgically induced astigmatism vector (P = .449), difference vector (P = .335), and magnitude of error (P = .413) between groups. The absolute angle of error was 1.88 ± 2.25 degrees in the small-incision lenticule extraction group and 1.37 ± 1.58 degrees in the LASIK group (P = .217). Small-incision lenticule extraction offered astigmatic correction comparable to LASIK in eyes with high myopic astigmatism.

Chan TCY ，Wang Y ，Ng ALK ，Zhang J ，Yu MCY ，Jhanji V ，Cheng GPM ... -  《-》

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

To compare astigmatic correction between femtosecond-assisted laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE). A total of 111 patients were included in this prospective study. Fifty-seven eyes were treated with LASIK and 54 eyes were treated with SMILE for myopia with low to moderate (-0.25 to -4.0 D) astigmatism. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity and manifest refraction were measured preoperatively and at 1 and 3 months postoperatively. Visual and refractive outcomes were reported. Changes in refractive astigmatism were evaluated using vector analysis. Preoperative characteristics were similar between both groups. The UDVA at 1 and 3 months was better in the LASIK group compared with the SMILE group (p<0.009). Postoperative cylinder was higher in the SMILE group (p<0.001). Fewer eyes attained the attempted cylindrical correction in the SMILE group (p<0.029). Vector analysis showed no significant difference in target-induced astigmatism (p=0.091) and angle of error (p>0.596) between the two groups. Surgically induced astigmatism was significantly lower in the SMILE group (p<0.023), while the difference vector (p<0.001) and absolute angle of error (p<0.016) were significantly higher in the SMILE group. No significant difference was found in these parameters between 1 and 3 months in both groups (p>0.122). Our results showed that SMILE offered a less favourable astigmatic correction comparable to femtosecond-assisted LASIK in eyes with low to moderate myopic astigmatism. The alignment of treatment was more variable in SMILE, leading to a lower efficacy compared with LASIK by 3 months postoperatively.

Chan TC ，Ng AL ，Cheng GP ，Wang Z ，Ye C ，Woo VC ，Tham CC ，Jhanji V ... -  《-》

Short and long term outcomes after small-incision lenticule extraction: A tertiary referral centre experience.

The objective of this study is to evaluate the preoperative and short- and long-term postoperative results in terms of visual acuity, refractive error, and corneal wavefront aberrations in patients with myopia and myopic astigmatism undergoing small incision lenticule extraction (SMILE). Seventy-nine eyes of 52 myopes with or without astigmatism (41 right and 38 left) were enrolled in this retrospective study. The measurements included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE) and wavefront aberrations. All the measurements before and after SMILE surgery were systematically recorded. Mean preoperative UDVA was 1.19±0.24 logMAR and improved to 0.06±0.17 logMAR at the 3-year postoperative follow-up. At the conclusion of the 3-year follow-up, UDVA was better than or equal to 20/20 and 20/25 in 73% and 84% of eyes, respectively. At 1 month postoperatively, CDVA was 0.05±0.23 logMAR and significantly lower than the preoperative CDVA, 0.02±0.04 log MAR (P>0.05). However, at 1 year and 3 years after surgery, CDVA showed a significant increase compared to preoperative CDVA. At the conclusion of the 3-year follow-up, SE was -0.47 D, and 69.6% and 83.5% of the eyes were within±0.50 D and±1.00 D, respectively, of the intended correction. HOA's, coma, and spherical aberration increased significantly. No significant change in trefoil was detected. This study showed that SMILE produces a stable, safe outcome for surgical treatment of myopia and myopic astigmatism.

Yesilkaya C ，Arıcı M ，Yıldırım Y ，Agca A ，Demircan A ，Taskapılı M ... -  《-》