Refractive Lenticule Extraction Research Articles

Small incision lenticule extraction (SMILE) techniques: patient selection and perspectives.

Refractive lenticule extraction is becoming the procedure of choice for the management of myopia and myopic astigmatism owing to its precision, biomechanical stability, and better ocular surface. It has similar safety, efficacy, and predictability as femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and is associated with better patient satisfaction. The conventional technique of small incision lenticule extraction (SMILE) involves docking, femtosecond laser application, lenticule dissection from the surrounding stroma, and extraction. It has a steep learning curve compared to conventional flap-based corneal ablative procedures, and the surgical technique may be challenging especially for a novice surgeon. As SMILE is gaining worldwide acceptance among refractive surgeons, different modifications of the surgical technique have been described to ease the process of lenticule extraction and minimize complications. Good patient selection is essential to ensure optimal patient satisfaction, and novice surgeons should avoid cases with low myopia (thin refractive lenticules), difficult orbital anatomy, high astigmatism, or uncooperative, anxious patients to minimize complications. A comprehensive MEDLINE search was performed using “small incision lenticule extraction,” “SMILE,” and “refractive lenticule extraction” as keywords, and we herein review the patient selection for SMILE and various surgical techniques of SMILE with their pros and cons. With increasing surgeon experience, a standard technique is expected to evolve that may be performed in all types of cases with optimal outcomes and minimal adverse effects.

Clinical evaluation of a new correction algorithm for dynamic Scheimpflug analyzer tonometry before and after laser in situ keratomileusis and small-incision lenticule extraction

To compare a biomechanically corrected intraocular pressure (bIOP) algorithm provided by the dynamic Scheimpflug analyzer (Corvis ST) with Goldmann applanation tonometry IOP (Goldmann IOP) and standard dynamic Scheimpflug analyzer IOP measurements before and after laser insitu keratomileusis (LASIK) and refractive lenticule extraction small-incision lenticule extraction (SMILE) surgeries. Smile Eye Clinic, Munich, Germany, and University of Liverpool, Liverpool, United Kingdom. Retrospective case series. Patients scheduled for LASIK and patients scheduled for small-incision lenticule extraction for myopia or myopic astigmatism were included. The preoperative and postoperative evaluations included Goldmann, Scheimpflug tomography, and dynamic Scheimpflug analyzer IOP measurements. The study comprised 14 patients in the LASIK group and 22 patients in the small-incision lenticule extraction group. Preoperative Goldmann IOP and Scheimpflug analyzer IOP values showed significant positive correlation with central corneal thickness (CCT) (P=.05 for LASIK; P=.003 for small-incision lenticule extraction). No significant correlation was found between bIOP and CCT (P>.05). After both surgeries, there were significant decreases in Goldmann IOP (-3.2mm Hg±3.4 [SD] and -3.2±2.1mm Hg, respectively; both P<.001) and Scheimpflug analyzer IOP (-3.7±2.1mm Hg and -3.3±2.0mm Hg, respectively, both P<.001) compared with preoperative readings, whereas bIOP did not differ significantly (0.1±2.1mm Hg and 0.8±1.8mm Hg, respectively; P=.80 and P=.273, respectively). The bIOP readings before and after LASIK and small-incision lenticule extraction were neither significantly different nor correlated with CCT. In contrast, both Goldmann IOP and Scheimpflug analyzer IOP had significant reductions postoperatively and showed significant correlation with CCT preoperatively.

Intraoperative complications of refractive small incision lenticule extraction in the early learning curve.

PurposeTo study the intraoperative complications of refractive small incision lenticule extraction (ReSMILE push-up technique), and to record the mean intraoperative duration time of all surgeries for the refractive surgeon in his early learning curve.SettingEbsar Eye Center, Benha, Egypt.DesignA prospective, single-center, cohort clinical study.MethodsThis prospective, single-center, cohort clinical study was done on patients with myopia and myopic astigmatism, who were enrolled for SMILE surgeries. All the SMILE operations were performed by a single refractive surgeon (AMH), by using only the ReSMILE push-up technique.ResultsA total of 190 eyes were operated upon, using the (ReSMILE push-up technique), with a mean follow-up period of 2 months. The intraoperative complications have been recorded for all patients. The mean operative duration of all cases was 4.45±1.45 minutes.ConclusionThe ReSMILE: push-up technique seems to facilitate visualization of the edge of the lenticule of the SMILE surgery, especially for the refractive surgeon in his early learning curve.

Refractive lenticule extraction small incision lenticule extraction: A new refractive surgery paradigm.

Small incision lenticule extraction (SMILE), a variant of refractive lenticule extraction technology is becoming increasingly popular, as a flapless and minimally invasive form of laser vision correction (LVC) for the treatment of myopia and myopic astigmatism. This review aims at summarizing the principles, surgical technique, and clinical outcomes in terms of visual and refractive results, safety, efficacy, postoperative dry eye, aberrations, and biomechanics of SMILE and its comparison with other conventional techniques of LVC, such as laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Recent advancements in the laser frequency and energy delivery patterns, instrumentation, and surgical techniques have shown significant improvement in the visual recovery and outcomes after SMILE, compared to the initial results published by Sekundo and Shah et al. Most of the recently published literature on long-term outcomes of SMILE shows excellent stability of the procedure, especially for higher myopia. In terms of the postoperative dry eye, SMILE shows a clear advantage over LASIK as numerous studies have shown significant differences about the Schirmer's, Tear film break up time, corneal sensitivity, and corneal nerve regeneration to be better following SMILE compared to LASIK. There is some evidence that since the Bowman's membrane (BM) and the anterior lamellae remain intact after SMILE, this may be a potential advantage for corneal biomechanics over LASIK and PRK where the BM is either severed or ablated, respectively, however, the data on biomechanics are inconclusive at present. Overall, this procedure has proved to be promising, delivering equivalent, or better visual and refractive results to LASIK and providing clear advantage in terms of being a flapless, minimally invasive procedure with minimal pain and postoperative discomfort thus offering high patient satisfaction.

Femtosecond Laser-Assisted Stromal Lenticule Addition Keratoplasty for the Treatment of Advanced Keratoconus: A Preliminary Study.

To investigate the in vivo effect of a novel femtosecond laser-assisted procedure termed stromal lenticule addition keratoplasty for advanced keratoconus. Ten patients with stage III and IV stable keratoconus were included. Negative meniscus-shaped stromal lenticules were produced from corneoscleral eye bank buttons with a refractive lenticule extraction procedure with a 500-kHz VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Recipient corneas underwent a modified femtosecond laser flap-cut procedure to produce an intrastromal pocket and lenticules were implanted. Patients were followed up for 6 months after surgery with determination of uncorrected (UDVA) and corrected (CDVA) distance visual acuity, subjective refraction and topographic corneal curvature changes, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal microscopy. Comparison of preoperative and 6-month postoperative UDVA and CDVA showed statistically significant improvements (P = .024 and .007, respectively) from 1.58 ± 0.36 to 1.22 ± 0.37 and from 1.07 ± 0.17 to 0.70 ± 0.23 logMAR. Eight of 10 eyes showed an improvement in UDVA (P < .001) that ranged between one and three lines, whereas all but one eye presented improved CDVA. Corneal topography documented a decrease between preoperative and 6-month postoperative anterior mean curvature (AVG-K at 3 mm) and anterior Q values (P = .005). AS-OCT showed a significant increase in thickness of the central and mid-peripheral cornea produced by the lenticule implantation (P = .005). The stromal lenticule addition keratoplasty procedure was clinically efficient in improving the corneal shape and vision in patients with keratoconus. Negative meniscus-shaped lenticule addition induced a flattening of the cone while increasing corneal thickness. [J Refract Surg. 2018;34(1):36-44.].

Wound healing in rabbit corneas after flapless refractive lenticule extraction with a 345 nm ultraviolet femtosecond laser

To characterize corneal wound healing in a rabbit model after flapless refractive lenticule extraction with a 345 nm ultraviolet femtosecond laser. Departments of Ophthalmology and Anatomy II, University of Erlangen-Nürnberg and Wavelight GmbH, Erlangen, Germany. Experimental study. Flapless refractive lenticule extraction was performed in 1 eye each of 20 New Zealand white rabbits (-5.0 diopters). Groups of 4 animals were euthanized after 48 hours, 1 week, 2 weeks, 4 weeks, and 3 months, respectively. Corneal samples were prepared for histology and fluorescence microscopy. To assess corneal cell death, proliferation, and myofibroblastic transdifferentiation, terminal uridine deoxynucleotidyl nick end-labeling (TUNEL) assay as well as immunostaining for Ki67 and α-smooth muscle actin (αSMA) were performed on sagittal cryosections. Histology revealed a zone of keratocyte depletion with a thickness of approximately 50 μm around the extraction site. At 48 hours, pronounced TUNEL staining of keratocytes was detected around the interface (159.9 cells/mm ± 18.4 [SD]), which steadily decreased to 74.9 ± 19.8 cells/mm at 1 week and 5.7 ± 4.8 cells/mm at 2 weeks. Ki67 staining of keratocytes was evident at 48 hours (10.0 ± 3.8 cells/mm), which then decreased at 1 week (5.2 ± 1.7 cells/mm) and 2 weeks (0.4 ± 0.5 cells/mm). From 4 weeks onward, no TUNEL or Ki67 staining was detected. The corneal stroma was αSMA-negative at all timepoints. Application of the 345 nm laser showed no signs of problematic repair processes in the cornea, which supports the initiation of the clinical phase.

A Multicenter Retrospective Survey of Refractive Surgery in 78,248 Eyes.

To retrospectively evaluate the current practice, trends, and outcomes of refractive surgery in Japan. This multicenter survey comprised 78,248 eyes of 39,727 consecutive patients who underwent refractive surgery at 45 major institutions in Japan. The corresponding ophthalmologists responded to a selfadministered questionnaire. The authors especially evaluated the safety, efficacy, predictability, stability, and adverse events of LASIK and phakic intraocular lens (IOL) implantation 3 months postoperatively. The most common refractive surgery was LASIK (90.9%), followed by corneal inlay (5.0%), posterior chamber phakic IOL implantation (1.3%), laser-assisted subepithelial keratomileusis (1.0%), refractive lens exchange (0.9%), photorefractive keratectomy (0.3%), and refractive lenticule extraction (0.2%). For subgroup analysis, 69,987 eyes (99.5%) and 67,512 eyes (95.9%) achieved corrected and uncorrected distance visual acuity of 20/20 or better, respectively, after LASIK, and 935 eyes (98.8%) and 890 eyes (94.1%), respectively, after phakic IOL implantation. There were 69,176 eyes (98.3%) and 908 eyes (96.0%) within ±1.00 diopter (D) of the attempted correction after LASIK and phakic IOL implantation, respectively. There were 1,926 eyes (2.7%) and 1 eye (0.1%) with changes in refraction of 1.00 D or less from 1 week to 3 months after LASIK and phakic IOL implantation, respectively. No vision-threatening complications occurred in any case. According to this survey, LASIK remains the most prevalent surgical technique in Japan. Both LASIK and phakic IOL implantation offered good safety and efficacy outcomes, yielding predictable and stable results. [J Refract Surg. 2017;33(9):598-602.].

Predictability of SMILE over four years in high myopes

To determine whether the visual outcomes of the refractive surgery technique small incision lenticule extraction (SMILE), are stable, effective, and predictable for high myopia over a four-year period. This is a retrospective study. The data were collected between March 2012 and July 2016. Two hundred and forty-eight patients participated in the study; that is, 496eyes: 140 eyes of 70 patients (52 women/18 men) were classified into the highly myopic group (refraction measured in spherical equivalent (RMSE)>-6D), and 356 eyes of 178 patients (98 women/80 men) into the control group (RMSE<-6D). Follow-up tests were conducted immediately following the procedure (D+1), after three months, after one year, and after four years. Refraction, uncorrected visual acuity (UCVA), and best visual corrected acuity (BCVA) were measured. The highly myopic group (HMG) contained more women, and astigmatism was higher for this group than for the control group (CG). These were BCVA, refractive stability, the index of safety (SI: BCVA preoperatively D+1/BCVA postoperatively), and predictability (the percentage of eyes within±0.5D of the target). In both groups, UCVA was better after the fourth year than it was immediately after the procedure (HMG: P=0.001; CG: P=0.001). Although it differed at one year (P=0.01), the groups' refractive stability tended to converge over four years (P=0.138). The groups' SI was found to be identical in the four follow-up tests (P=0.734 at D+1; P=0.07 at M+1; P=0.160 at M3 and Y1; and P=0.274 at Y4). For the HMG, SI stability was attained after three months (1.00±0.1); whereas it was attained after one month (0.91±0.11) for the CG. Four years after the surgery, we observed that 87% of the operated-upon eyes in the HMG were within 0.5D of the target. SMILE is a good refractive surgery technique for treating high myopia. It yields stable, safe, effective, and predictable results over four years.

Femtosecond Lasers and Corneal Surgical Procedures.

Our purpose is to present a broad review about the principles, early history, evolution, applications, and complications of femtosecond lasers used in refractive and nonrefractive corneal surgical procedures. Femtosecond laser technology added not only safety, precision, and reproducibility to established corneal surgical procedures such as laser in situ keratomileusis (LASIK) and astigmatic keratotomy, but it also introduced new promising concepts such as the intrastromal lenticule procedures with refractive lenticule extraction (ReLEx). Over time, the refinements in laser optics and the overall design of femtosecond laser platforms led to it becoming an essential tool for corneal surgeons. In conclusion, femtosecond laser is a heavily utilized tool in refractive and nonrefractive corneal surgical procedures, and further technological advances are likely to expand its applications.

A Multicenter Prospective Cohort Study on Refractive Surgery in 15 011 Eyes

To assess the clinical outcomes of currently used refractive surgery procedures performed in 2015. Prospective, multicenter cohort study. This prospective study included 15 011 eyes of 7622 consecutive patients who underwent laser insitu keratomileusis (LASIK), surface ablation, refractive lenticule extraction (ReLEx), or phakic intraocular lens (IOL) implantation at 42 major institutions. We determined the safety, efficacy, predictability, stability, and adverse events of these surgeries preoperatively and at 1week and 1 and 3months postoperatively. Mean logMAR corrected distance visual acuity 3months after LASIK, surface ablation, ReLEx, posterior chamber phakic IOL, or iris-supported phakic IOLimplantation was-0.18 ± 0.07,-0.16 ±0.08,-0.17 ±0.09,-0.21 ± 0.08, and-0.10 ± 0.12, respectively; the corresponding values for logMAR uncorrected distance visual acuity were-0.15 ± 0.11,-0.12±0.12,-0.12 ± 0.13,-0.15 ± 0.12, and 0.01 ± 0.21, respectively. The percentages within ±1.0 diopter (D) of the attempted correction were 96%, 93%, 97%, 99%, and 84% after LASIK, surface ablation, ReLEx, posterior chamber phakic IOL, and iris-supported phakic IOL implantation, respectively. Refractive change from 1week to 3months was-0.08 ± 0.07, 0.21 ± 0.63,-0.04 ± 0.41, 0.01 ± 0.31, and 0.01 ± 0.46 D, respectively. No vision-threatening complications occurred during the observation period. Although more prolonged follow-up is still necessary, currently used refractive surgery procedures have good safety and efficacy outcomes, yielding predictable and stable results. Contemporary LASIK, surface ablation, ReLEx, and phakic IOL implantation appear to be feasible options for the treatment of refractive errors.

Refractive small-incision lenticule extraction: Push-up and push-down techniques

Neither author has a financial or proprietary interest in any material or method mentioned.

A Novel Tectonic Keratoplasty with Femtosecond Laser Intrastromal Lenticule for Corneal Ulcer and Perforation.

Background:Small incision refractive lenticule extraction (SMILE) is an effective laser procedure that treats myopia. This research was to describe a novel approach to treat corneal ulcer or perforation using the corneal lenticules obtained from SMILE and to evaluate the safety and effectiveness of tectonic keratoplasty with femtosecond laser intrastromal lenticule (TEKIL).Methods:A total of twenty patients (22 eyes) were monitored for at least 6 months and were assessed using slit lamp microscopy, optical coherence tomography, and best-corrected visual acuity (BCVA). Postoperative complications throughout the study period were recorded.Results:Corneal ulcer in 14 patients (16 eyes) and corneal perforation in six patients (6 eyes) were treated with TEKIL. The patients were ten females and ten males, with a mean age of 58.5 ± 16.3 years (range: 16–81 years). In this study, the most causes of corneal ulcer or perforation were immunologic causes (54.5%). After TEKIL procedure, global integrity was achieved in all cases. No immune rejection or perforation was detected. The mean BCVA improved from 0.17 ± 0.20 preoperatively to 0.27 ± 0.25 postoperatively at the final follow-up (t = 2.095, P = 0.052). The postoperative BCVA improved in 12 eyes (54.5%) and maintained in nine eyes (40.9%). Vision function successfully maintained in all eyes (100%). In three cases, corneal ulcers were treated by reoperation of TEKIL at 3 months after the initial surgery for the reason that the residual corneal thickness was <250 μm.Conclusions:TEKIL seems to be an effective treatment for corneal ulcer and perforation in the condition of emergency and donor shortage.

Epithelial Thickness Profile Changes Following Small Incision Refractive Lenticule Extraction (SMILE) for Myopia and Myopic Astigmatism.

To evaluate the epithelial thickness profile changes following small incision refractive lenticule extraction (SMILE) and study their correlation with the amount of myopia corrected. Epithelial thickness was measured in nine zones with spectral-domain anterior segment optical coherence tomography (SD-OCT) across a 6-mm diameter preoperatively and at 1 day, 2 weeks, and 3 months postoperatively. The observed changes were correlated with the degree of myopia corrected. The study included 100 eyes from 50 eligible patients (32 females, 18 males) with a mean age of 24.4 ± 2.8 years. Thirty-eight eyes underwent SMILE for low (spherical equivalent [SE] < -4.00 diopters [D]), 44 eyes for moderate (SE -4.00 to -6.00 D), and 18 eyes for high (SE > -6.00 to -10.00 D) myopia with 6.71 ± 1.65, 6.82 ± 0.21, and 6.44 ± 0.2 mm optical zones, respectively. At 3 months, a statistically significant epithelial thickness increase was observed in the central zone (6.83% for low, 9.26% for moderate, and 12.7% for high myopia, P < .05 for all groups) and superior zone (3.98% for low, 7.82% for moderate, and 9.87% for high myopia) across all three groups, which correlated positively with the degree of myopia corrected (r(2) = 0.723 for central zone, r(2) = 0.585 for superior zone, P < .001 for both zones). None of the other zones showed any statistically significant changes at 3 months. Four eyes of two patients with high myopia (SE > -8.00 D) had regression due to significant epithelial thickening. Preliminary results suggest that epithelial thickness profile changes after SMILE may have an impact on the refractive outcome in the long-term postoperative period, especially in higher degrees of myopia. [J Refract Surg. 2016;32(7):473-478.].

Application of the SMILE-Derived Glued Lenticule Patch Graft in Microperforations and Partial-Thickness Corneal Defects.

To report the initial clinical outcomes of the small incision lenticule extraction (SMILE)-derived glued lenticule patch graft for management of microperforations and complicated corneal tears. In this single-center case series, 7 eyes (of 7 patients) that presented with microperforations, partial-thickness corneal defect, and traumatic complicated corneal tear were repaired with a lenticule patch graft obtained from Refractive Lenticule Extraction (ReLEx) with the SMILE procedure. The patch was secured to the recipient eye using fibrin glue. Preoperatively, anterior segment optical coherence tomography was used to assess the depth of the defect and to decide the thickness of the lenticule. Patients were followed up on days 1, 7, and 15 and at 1 and 3 months postoperatively. Main outcome parameters measured were best-corrected visual acuity, clarity of the graft, and restoration of optical and tectonic integrity. All surgeries were uneventful. Significant improvement in visual acuity was seen from 15 days onward in 5 of 7 eyes. The lenticule graft was well apposed and remained clear until the last follow-up visit in all eyes treated. The patch graft from the SMILE-derived lenticule using fibrin glue seems to serve as a safe, feasible, and inexpensive surgical option for the management of microperforations and complicated corneal tears, especially in centers that perform the SMILE procedure in large numbers.

Five-year results of Small Incision Lenticule Extraction (ReLEx SMILE)

BackgroundTo evaluate the 5-year results of Refractive Lenticule Extraction (ReLEx) as Small Incision Lenticule Extraction (SMILE) technique for treatment of myopia and myopic astigmatism.MethodsIn 2008/2009, the worldwide first 91 eyes...

Complications of corneal lamellar refractive surgery

Techniques available for corneal lamellar refractive surgery are laser-assisted in situ keratomileusis (LASIK) using a microkeratome or femtosecond laser incision followed by excimer laser corneal ablation, and femtosecond laser-assisted refractive lenticule extraction (ReLEx). These treatments are nowadays considered to be safe and effective standard procedures for surgical correction of mild to moderate ametropia. Possible complications include too small or decentered optical zones, intraoperative flap cutting errors and postoperative inflammation (e.g. diffuse lamellar keratitis, DLK), epithelial or flap folds, epithelial ingrowths or iatrogenic ectasia. The occurrence of complications may be significantly reduced by compliance to corresponding standards of indication and treatment that are based on current scientific knowledge.

Posterior corneal curvature changes following Refractive Small Incision Lenticule Extraction

PurposeTo compare the posterior corneal curvature changes, in terms of corneal power and asphercity, following Refractive Small Incision Lenticule Extraction (ReLEx SMILE) procedure for low, moderate, and high myopia.MethodsThis retrospective, non randomized, comparative, interventional trial; included 52 eyes of 26 patients, divided in three groups: low myopia (myopia ≤3 D [diopters] spherical equivalent [SE]), moderate myopia (myopia >3 D and <6 D SE), and high myopia (myopia ≥6 D SE). All patients were treated for myopia and myopic astigmatism using ReLEx SMILE. The eyes were examined pre-operatively and 3 months post-operatively using SCHWIND SIRIUS, a three-dimensional rotating Scheimpflug camera with a Placido disc topographer to assess corneal changes with regard to keratometric power and asphericity of the cornea.ResultsA statistically significant increase in mean keratometric power in the 3, 5, and 7 mm zones of the posterior corneal surface compared with its pre-ReLEx SMILE value was detected after 3 months in the moderate myopia group (pre-operative [pre-op] −6.14±0.23, post-operative [post-op] −6.29±0.22, P<0.001) and high myopia group (pre-op −6.19±0.16, post-op −6.4±0.18, P<0.001), but there was no significant change in keratometric power of the posterior surface in the low myopia group (pre-op −5.87±0.17, post-op −6.06±0.29, P=0.143). Asphericity (Q-value) of the posterior surface changed significantly (P<0.001) after ReLEx SMILE in the moderate myopia group in the 3, 5, and 7 mm zones, and in the high myopia group in the 3 and 7 mm zones; but there was no significant change in the Q-value in the low myopia group in all three zones (pre-op 0.23±0.43, post-op −0.40±0.71, P=0.170), and in the high myopia group in the 5 mm zone (P=0.228).ConclusionReLEx SMILE causes significant changes in posterior corneal keratometric power and asphericity in moderate and high myopia, but the effect is subtle and insignificant in low myopia.

Postoperative ocular higher-order aberrations and contrast sensitivity: Femtosecond lenticule extraction versus pseudo small-incision lenticule extraction

To evaluate and compare changes in contrast sensitivity and ocular higher-order aberrations (HOAs) after femtosecond lenticule extraction (FLEx) and pseudo small-incision lenticule extraction (SMILE). Singapore National Eye Centre, Singapore. Retrospective case series. Patients had femtosecond lenticule extraction (Group 1) or pseudo small-incision lenticule extraction (Group 2) between March 2010 and December 2011. The main outcome measures were manifest refraction, HOAs, and contrast sensitivity 1, 3, 6, and 12months postoperatively. Fifty-two consecutive patients (102 eyes) were recruited, 21 patients (42 eyes) in Group 1 and the 31 patients (60 eyes) in Group 2. The uncorrected and corrected distance visual acuities were significantly better in Group 2 than in Group 1 at 12months (P = .032). There was no significant increase in 3rd- or 4th-order aberrations at 1year and no significant difference between the 2 groups preoperatively or postoperatively. At 1year, there was a significant increase in mesopic contrast sensitivity in Group 2 at 1.5 cycles per degree (cpd) (P = .008) that was not found in Group 1, and photopic contrast sensitivity at 6.0 cpd was higher in Group 2 (P = .027). These results indicate that refractive lenticule extraction is safe and effective with no significant induction of HOAs or deterioration in contrast sensitivity at 1year. Induction of HOAs was not significantly different between both variants of refractive lenticule extraction. However, there was significant improvement in photopic contrast sensitivity after pseudo small-incision lenticule extraction, which persisted through 1year. No author has a financial or proprietary interest in any material or method mentioned.

SMILE : correction de la myopie par ablation réfractive par laser femtoseconde d’un lenticule intracornéen

It is currently possible to obtain refractive correction without using an excimer laser; the technique is called ReLEx(®) (Refractive Lenticule extraction) and uses the femtosecond laser VisuMax(®) (Carl Zeiss Meditec, Jena, Germany). We present initial clinical experience with small-incision (4mm) lenticule extraction (SMILE) for the treatment of moderate to high myopia via a retrospective study of 106 myopic and astigmatic eyes. This retrospective study of 106 eyes measures postoperative visual acuity to determine the safety, efficacy and predictability of the technique. For SMILE, an intrastromal lenticule is cut with the VisuMax(®) femtosecond laser; it is then dissected and detached from the anterior and posterior stromal planes and finally removed through a 4mm incision. This procedure does not require the creation of a flap. The study is based on 106 eyes of 54 patients who underwent the surgery for moderate to high myopia, with or without associated astigmatism. Patient selection was the same as for LASIK. The average age of the patients was 33 ± 9 (20-54). The mean preoperative spherical equivalent was -6.22 ± 1.6 (-3; -9.75 D). The mean preoperative sphere was -5.88 D ± 1.52 (-3; -9.75 D) with a mean cylinder of -0.68 D ± 0.58 (0.00; -2.25). Postoperatively, 95% of patients had distance vision greater than or equal to 8/10. No loss of BCVA was noted. The mean postoperative spherical equivalent was -0.16 ± 0.35 D (-1.38; +0.88) with a mean sphere of 0.00 ± 0.34 D (-1,25; +1) and a mean cylinder of -0.31 ± 0.37 D (0; -1.5). One eye was converted to PRK because the incision site was covered by conjunctiva during the last 5 seconds of the laser phase. SMILE is a predictable and safe technique for the surgical correction of moderate to high myopia.

Anterior and Posterior Corneal Astigmatism after Refractive Lenticule Extraction for Myopic Astigmatism.

Purpose. To assess the amount and the axis orientation of anterior and posterior corneal astigmatism after refractive lenticule extraction (ReLEx) for myopic astigmatism. Methods. We retrospectively examined 53 eyes of 53 consecutive patients (mean age ± standard deviation, 33.2 ± 6.5 years) undergoing ReLEx to correct myopic astigmatism (manifest cylinder = 0.5 diopters (D)). Power vector analysis was performed with anterior and posterior corneal astigmatism measured with a rotating Scheimpflug system (Pentacam HR, Oculus) and refractive astigmatism preoperatively and 3 months postoperatively. Results. Anterior corneal astigmatism was significantly decreased, measuring 1.42 ± 0.73 diopters (D) preoperatively and 1.11 ± 0.53 D postoperatively (p < 0.001, Wilcoxon signed-rank test). Posterior corneal astigmatism showed no significant change, falling from 0.44 ± 0.12 D preoperatively to 0.42 ± 0.13 D postoperatively (p = 0.18). Refractive astigmatism decreased significantly, from 0.92 ± 0.51 D preoperatively to 0.27 ± 0.44 D postoperatively (p < 0.001). The anterior surface showed with-the-rule astigmatism in 51 eyes (96%) preoperatively and 48 eyes (91%) postoperatively. By contrast, the posterior surface showed against-the-rule astigmatism in all eyes preoperatively and postoperatively. Conclusions. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after ReLEx for myopic astigmatism.