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.

PURPOSE: 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. DESIGN: Prospective, multicenter clinical trial. PARTICIPANTS: 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. METHODS: -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. MAIN OUTCOME MEASURES: Corrected distance visual acuity, uncorrected distance visual acuity, manifest refraction, astigmatic outcomes, and adverse events. RESULTS: 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. CONCLUSIONS: 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.

A Technique to Reduce Incidence of Opaque Bubble Layer Formation During LASIK Flap Creation Using the VisuMax Femtosecond Laser.

PURPOSE: To identify risk factors for opaque bubble layer (OBL) formation and compare the incidence of OBL using a cone modification technique versus the original technique for LASIK flap creation using the VisuMax laser (Carl Zeiss Meditec, Jena, Germany). METHODS: This retrospective study examined videos of flap creation using the VisuMax laser to identify OBL occurrence. Eyes were divided into three groups: eyes where OBL occurred using the original technique (OBL group), eyes where OBL did not occur using the original technique (no OBL group), and eyes in which the cone modification technique was used for LASIK flap creation (larger flap diameter) (cone modification technique group). Preoperative measurements including simulated keratometry (flat and steep) values, white-to-white distance (WTW), pachymetry, patient age and gender, amount of correction, flap parameters, energy setting, corneal hysteresis, and corneal resistance factor were analyzed to identify parameters with statistical difference between the OBL and no OBL groups. Incidence of OBL was compared between the original and cone modification techniques. RESULTS: OBL incidence was significantly lower with the cone modification technique (7.6%; 7 of 92 eyes) than with the original technique (28.8%; 34 of 118 eyes) (Fisher's exact test, P = .0009). Factors identified with a significant difference between eyes with and without OBL using the original technique were: corneal thickness (OBL: 561.2 µm, no OBL: 549.6 µm, P = .0132), WTW diameter (OBL: 11.6 mm, no OBL: 11.9 mm, P = .0048), corneal resistance factor (OBL: 10.4 mm Hg, no OBL: 9.6 mm Hg, P = 0.0329), and corneal astigmatism (OBL: 0.80 diopter, no OBL: 1.00 diopter, P = .0472) CONCLUSIONS: Less astigmatic, thicker, denser, and smaller corneas increased the risk of OBL using the original technique for flap creation. The cone modification technique was associated with lower risk of OBL formation, even in eyes with significant risk factors for OBL using the original technique. [J Refract Surg. 2017;33(9):584-590.].

Treatment of Presbyopia in Emmetropes Using a Shape-Changing Corneal Inlay: One-Year Clinical Outcomes.

PURPOSE: To report 1-year safety and efficacy clinical outcomes of a shape-changing corneal inlay for the treatment of presbyopia. DESIGN: Prospective, nonrandomized, multicenter United States Food and Drug Administration Investigational Device Exemption clinical trial (clinicaltrials.gov identifier, NCT01373580). PARTICIPANTS: Nondominant eyes (N = 373) of emmetropic presbyopic subjects were implanted at 11 sites with the Raindrop Near Vision Inlay (ReVision Optics, Lake Forest, CA); 340 eyes underwent the 1-year follow-up visit. METHODS: The corneal inlay was implanted under a corneal flap at the center of the light-constricted pupil created with a femtosecond laser. MAIN OUTCOME MEASURES: For subjects completing the 1-year follow-up, monocular and binocular uncorrected and corrected visual acuity, refractive stability, contrast sensitivity (CS; photopic and mesopic), symptom and satisfaction questionnaire results, and adverse events. RESULTS: At 1 year in the treated eye, on average, uncorrected near visual acuity (UNVA) improved by 5.1 lines, uncorrected intermediate visual acuity (UIVA) improved by 2.5 lines, and uncorrected distance visual acuity (UDVA) decreased by 1.2 lines. From 3 months through 1 year, 93% of subjects achieved UNVA of 20/25 or better, 97% achieve UIVA of 20/32 or better, and 95% achieved UDVA of 20/40 or better. Binocularly, the mean UDVA exceeded 20/20 from 3 months through 1 year. Contrast sensitivity loss occurred only at the highest spatial frequencies, with no loss binocularly. Absent or mild scores were reported in 96% of subjects for visual symptoms (glare, halos, double vision, and fluctuations in vision), in 99% for ocular symptoms (pain, light sensitivity, and discomfort), and in 95% for dryness. Adverse events were treatable and resolved. Eighteen inlays were replaced, usually soon after implantation because of decentration, but UNVA was little affected in this group thereafter. In the 11 cases requiring inlay explantations, 100% achieved a corrected distance visual acuity of 20/25 or better by 3 months after explant. CONCLUSIONS: The Raindrop Near Vision Inlay provides significant improvement in near and intermediate visual performance, with no significant change in binocular distance vision or CS. Subject satisfaction is improved significantly with minimal ocular or visual symptoms.

Correction of low levels of astigmatism.

PURPOSE: To reevaluate the analysis of the correction of astigmatism. SETTING: Academia, industry, and private practice. DESIGN: Evaluation of diagnostic test or technology. METHODS: Astigmatic refractive surgery outcomes are based on vector methods, including the correction index (also known as the correction ratio), which is the ratio of the surgically induced astigmatism to the target induced astigmatism (TIA). Mean correction indices substantially greater than 1 have been reported for astigmatic corrections less than 1.00 diopter (D) and as representing systematic overcorrection. We hypothesize that this reflects a limitation of the correction index rather than systematic flaws in treatments. The theoretical mathematic behavior of the correction index was analyzed, accounting for variability in astigmatism measurement. Then, the impact of cylinder measurement variability on the mean correction index was modeled. A Monte Carlo simulation was performed and calculated 10 000 values of correction index for various values of TIA. Finally, correction indices from published and unpublished studies of refractive lasers were compared with the simulations. RESULTS: The mean correction index is always greater than 1 for the case of a perfect refractive correction; however, for astigmatic corrections less than 1.00 D, the mean correction index increases sharply because the measurement variability is similar in magnitude to TIA. Almost all previous studies show the predicted increase in the correction index for low astigmatic corrections. CONCLUSION: The correction index is a useful vector-based metric for the evaluation of refractive procedures, but mean values greater than 1 should be anticipated for lower astigmatic treatments and do not necessarily represent systematic overcorrection. FINANCIAL DISCLOSURE: Dr. Bullimore is a consultant to Alcon Surgical, Inc., Carl Zeiss Meditec AG, Digital Vision Systems, Essilor, Innovega, Inc., and Paragon Vision Sciences, Inc. Dr. Spooner is a consultant to Alcon Surgical, Inc., Carl Zeiss Meditec AG, Digital Vision Systems, Thru-Focus Optics LLC, and i2eyediagnostics, Ltd. Dr. Dishler is a consultant to Carl Zeiss Meditec AG and Revision Optics, Inc. Dr. Sluyterman is an employee of Carl Zeiss Meditec AG.

Surface quality of human corneal lenticules after SMILE assessed using environmental scanning electron microscopy.

PURPOSE: To assess the cut quality of the anterior and posterior surfaces of intrastromal refractive lenticules removed during small incision lenticule extraction (SMILE). METHODS: The VisuMax femtosecond laser (500 kHz; Carl Zeiss Meditec, Dublin, CA) was used to perform SMILE on 8 eyes of 5 individuals to correct only myopia (no cylinder). The cut energy index was 26 (equivalent to an energy of 130 nJ) with a 2.5 × 2.5 µm spot/track separation. The lenticule diameter was 6.5 mm with a minimum edge thickness of 15 µm and the cap diameter was 7.3 mm with an intended thickness of 120 µm. After laser treatment, the lenticule was loosened with a spatula and removed with forceps. The extracted lenticules were placed in 2% formalin and sent for imaging with an environmental scanning electron microscope. Images of the anterior and posterior surfaces of the lenticules were obtained at multiple magnifications (100×, 250×, and 500×). Surface quality was evaluated by an investigator who specializes in electron microscopy using three criteria: overall surface regularity, percent of surface irregularity, and position of irregular area. RESULTS: Both the anterior and posterior surfaces of the extracted lenticules were smooth and absent of surface irregularities. The cut edges also appeared uniform. Jagged edges were seen in several images, but were clearly caused by the forceps during extraction. CONCLUSIONS: Using the VisuMax laser to perform SMILE produces smooth cuts absent of surface irregularities.

One-year safety and efficacy results of a hydrogel inlay to improve near vision in patients with emmetropic presbyopia.

PURPOSE: To conduct a feasibility study of the safety and efficacy of a corneal contouring inlay as a treatment for emmetropic presbyopia. METHODS: The Raindrop corneal inlay (ReVision Optics, Inc., Lake Forest, CA) was implanted on the corneal stromal bed beneath a keratotomy flap in 20 nondominant eyes of 20 patients. The implant is designed to cause a change in the curvature of the overlying cornea, with a subsequent multifocal change in refractive power. Efficacy outcome was defined as at least 75% of eyes with uncorrected near visual acuity of 0.3 logMAR (20/40 Snellen) or better at 6 months. Main safety outcomes were retention of preoperative best-corrected distance visual acuity and reports of adverse events. Other outcome measures included contrast sensitivity; near, intermediate, and distance visual acuities; patient satisfaction; spectacle use; and complications. RESULTS: All implanted eyes achieved uncorrected near visual acuity of 0.3 logMAR (20/40 Snellen) or better by the 1-week postoperative examination and remained so throughout the 1-year follow-up period, also averaging less than 0.1 logMAR (20/25 Snellen) monocularly and binocularly throughout that period. Mean binocular uncorrected distance visual acuity remained within 0.02 logMAR of the preoperative mean throughout the study. One patient who was dissatisfied with the resulting vision underwent explantation. At 1 year, 16 of 19 patients seldom or never wore glasses and all 19 were satisfied or very satisfied with their overall vision. CONCLUSIONS: The hydrogel corneal inlay improved uncorrected near and intermediate visual acuity in patients with emmetropic presbyopia, with high patient satisfaction and little effect on distance visual acuity.

Transient light sensitivity after femtosecond laser flap creation: clinical findings and management.

PURPOSE: To describe the constellation of subjective and objective findings associated with unusual occurrences of photosensitivity after laser in situ keratomileusis (LASIK) with femtosecond flap creation and identify optimal management strategies. METHODS: Demographic data, laser settings, subjective complaints, clinical findings, treatment, and response to treatment were recorded for suspected cases of transient postoperative photosensitivity from 3 surgeons operating at 3 different sites. All cases were estimated for the period covering the suspected cases at each site to assess incidence. Additional cases were solicited from IntraLase users via a survey. RESULTS: For the 3 sites, 63 eyes from 33 patients were reported of a total estimated case log of 5667 (incidence, 1.1%). Average age was 41 years, and 51.7% of patients were women. Onset of symptoms ranged from 2 to 6 weeks after uneventful LASIK. All patients were treated with prednisolone acetate drops, whereas 1 surgeon also used Restasis (cyclosporine ophthalmic solution 0.05%). Patients noted improvement of symptoms within 1 week of treatment. When the raster and side-cut energy settings were lowered (by an average of 24% and 33%, respectively), significant reductions in incidence were noted. Similar findings were reported by 3 additional surgeons reporting 17 cases in the survey of IntraLase users. CONCLUSIONS: This report describes a new complication of LASIK performed with a femtosecond laser keratome that may be related to the pulse energy used for flap creation. Although there is no loss of uncorrected visual acuity, symptoms can be prolonged, especially without prompt steroid therapy. Technical advances that reduced pulse energies appear to decrease the incidence.