Glenn I Carp

Outcomes of Small Incision Lenticule Extraction (SMILE) in Low Myopia

PURPOSE To report the visual and refractive outcomes of small incision lenticule extraction for low myopia using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). METHODS A retrospective analysis of 120 consecutive small incision lenticule extraction procedures was performed for low myopia. Inclusion criteria were preoperative spherical equivalent refraction up to -3.50 diopters (D), cylinder up to 1.50 D, and corrected distance visual acuity of 20/20 or better. Outcomes analysis was performed for all eyes with 1-year follow-up according to the Standard Graphs for Reporting Refractive Surgery, and also including mesopic contrast sensitivity. RESULTS One-year data were available for 110 eyes (92%). Preoperatively, mean spherical equivalent refraction was -2.61 ± 0.54 D (range: -1.03 to -3.50 D) and mean cylinder was 0.55 ± 0.38 D (range: 0.00 to 1.50 D). Postoperatively, mean spherical equivalent refraction was -0.05 ± 0.36 D (range: -0.94 to +1.25 D) and mean cylinder was ± 0.50 D in 84% and ± 1.00 D in 99% of eyes. Uncorrected distance visual acuity was 20/20 or better in 96% of eyes and 20/25 or better in 100% of eyes. One line of corrected distance visual acuity was lost in 9%, but no eyes lost two or more lines. There was an initial overcorrection in mean spherical equivalent refraction on day 1 (+0.37 D) as expected, which regressed to +0.10 D at 1 month and -0.05 D at 3 months, after which stability was reached (mean spherical equivalent refraction was -0.05 D at 1 year). Contrast sensitivity at 1 year was slightly increased at 3, 6, 12, and 18 cycles per degree (P < .05). CONCLUSIONS Small incision lenticule extraction for low myopia was found to be safe and effective with outcomes similar to those previously reported for LASIK.

Femtosecond Laser-Assisted Keyhole Endokeratophakia: Correction of Hyperopia by Implantation of an Allogeneic Lenticule Obtained by SMILE From a Myopic Donor

PURPOSE To describe endokeratophakia in which a small incision lenticule extraction (SMILE) lenticule from a myopic patient is implanted into a recipient eye through a small incision to correct hyperopia. METHODS A 23-year-old aphakic woman presented following cataract surgery to remove a childhood congenital cataract with hyperopia of +12.00 -1.50 × 155, corrected distance visual acuity of counting fingers, and exotropia. A SMILE procedure using the VisuMax femto-second laser (Carl Zeiss Meditec, Jena, Germany) was performed on a donor patient with high myopia and the extracted lenticule was stored (power -10.50 diopter sphere, optical zone 5.75 mm, central lenticule thickness 127 μm). In the recipient eye, a pocket lamellar incision was created using the VisuMax SMILE software. The upper interface was separated and the donor lenticule was inserted through the small incision. RESULTS One year postoperatively, retinoscopy refraction was +7.50 -3.00 × 150, a spherical equivalent refraction reduction of 5.25 diopters. Mean keratometric power increased by 2.91 diopters. The posterior surface elevation changed significantly with a central bulge into the anterior chamber. Central corneal thickness by Pentacam (Oculus Optikgeräte, Wetzlar, Germany) increased by 121 μm. Central lenticule thickness was 130 μm and central epithelial thickness was 43 μm measured by RTVue OCT (Optovue Inc., Fremont, CA). The cornea remained clear over the 1-year postoperative period. CONCLUSIONS Endokeratophakia appears to be a viable procedure for correcting hyperopia on the cornea by implantation of an extracted myopic SMILE lenticule from a donor patient. However, posterior surface changes and epithelial remodeling resulted in only 50% of the intended correction. No adverse side effects were observed following implantation of donor tissue for 1 year.

LASIK for Presbyopia Correction in Emmetropic Patients Using Aspheric Ablation Profiles and a Micro-monovision Protocol With the Carl Zeiss Meditec MEL 80 and VisuMax

PURPOSE To evaluate the monocular and binocular visual outcomes of LASIK with an aspheric micro-mono-vision protocol in emmetropic patients with presbyopia. METHODS A retrospective, noncomparative case series included 296 eyes from 148 consecutive emmetropic patients with presbyopia who were treated with LASIK-induced micro-monovision. The CRS-Master software was used to generate ablation profiles for the MEL 80 excimer laser (Carl Zeiss Meditec) and flaps were created using the VisuMax femtosecond laser (Carl Zeiss Meditec). The target refraction was plano for distance eyes (dominant eye) and between -1.00 and -1.88 diopters (D) for near eyes. Patients were followed for 1 year. Emmetropia was defined for inclusion as spherical equivalent refraction ⩾- 0.88 D, sphere ⩽+1.00 D, and cylinder ⩽1.25 D. Median patient age was 55 years (range: 44 to 65 years). Median follow-up was 12.9 months. RESULTS Mean deviation from intended correction was +0.02±0.35 D, with 91% within ±0.50 D and 100% within ±1.00 D. Of distance eyes, 95% achieved uncorrected distance visual acuity (UDVA) of 20/20 or better and 100% achieved 20/32 or better. Binocularly, 98% of patients achieved UDVA of 20/20 or better and 100% achieved 20/32 or better; 96% achieved uncorrected near visual acuity of J2 and 99% could read J3 or better. No eyes lost 2 or more lines of corrected distance visual acuity. An average increase of 0.05 logMAR was noted in distance-corrected near visual acuity. A small increase occurred in mesopic contrast sensitivity (CSV-1000, VectorVision Inc) at 3 cycles per degree (cpd) (P=.016) and no change at 6, 12, or 18 cpd. CONCLUSIONS This aspheric micro-monovision protocol was a well-tolerated and effective procedure for treating emmetropic patients with presbyopia.

Optical Zone Centration Accuracy Using Corneal Fixation-based SMILE Compared to Eye Tracker-based Femtosecond Laser-assisted LASIK for Myopia.

PURPOSE To compare the optical zone centration accuracy between myopic eyes treated with small incision lenticule extraction (SMILE) and LASIK. METHODS Retrospective analysis of 100 consecutive eyes treated with SMILE (the SMILE group) with the corneal fixation-based centration VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) and a matched group of 100 eyes treated with LASIK (the LASIK group) with VisuMax flap creation and eye tracker-based centration MEL 90 excimer laser (Carl Zeiss Meditec) ablation. In SMILE, the corneal vertex of the coaxially fixating eye was aligned with the vertex of the curved contact glass. In LASIK, the treatment was centered on the coaxially sighted corneal light reflex (first Purkinje image). A tangential (instantaneous) curvature preoperative to postoperative difference map was generated for each eye. A fixed grid and set of concentric circles were superimposed on the difference map to measure the offset between the optical zone center and corneal vertex (0,0), and vector analysis was used for comparative analysis at 3 months postoperatively. RESULTS Mean centration offset was 0.20 ± 0.11 mm for the SMILE group and 0.17 ± 0.10 mm for the LASIK group, with no statistically significant difference between groups (P >.05). In the SMILE group, the optical zone was centered within 0.1 mm of the corneal vertex in 17% of eyes, within 0.2 mm in 55% of eyes, within 0.3 mm in 81% of eyes, and within 0.4 mm in 96% of eyes. In the LASIK group, the optical zone was centered within 0.1 mm of the corneal vertex in 24% of eyes, within 0.2 mm in 62% of eyes, within 0.3 mm in 92% of eyes, and within 0.4 mm in 98% of eyes. There was no systematic directional decentration in either group. CONCLUSION Optical zone centration accuracy was no different between SMILE and LASIK with the MEL 90 laser.

Reproducibility of manifest refraction between surgeons and optometrists in a clinical refractive surgery practice

Purpose To measure and compare the interobserver reproducibility of manifest refraction according to a standardized protocol for normal preoperative patients in a refractive surgery practice. Setting Private clinic, London, United Kingdom. Design Retrospective case series. Methods This retrospective study comprised patients attending 2 preoperative refractions before laser vision correction. The first manifest refraction was performed by 1 of 7 optometrists and the second manifest refraction by 1 of 2 surgeons, all trained using a standard manifest refraction protocol. Spherocylindrical data were converted into power vectors for analysis. The dioptric power differences between observers were calculated and analyzed. Results One thousand nine hundred twenty‐two consecutive eyes were stratified into a myopia group and a hyperopia group and then further stratified by each surgeon–optometrist combination. The mean surgeon–optometrist dioptric power difference was 0.21 diopter (D) (range 0.15 to 0.32 D). The mean difference in spherical equivalent refraction was 0.03 D, with 95% of all refractions within ±0.44 D for all optometrist–surgeon combinations. The severity of myopic or hyperopic ametropia did not affect the interobserver reproducibility of the manifest refraction. Conclusions There was close agreement in refraction between surgeons and optometrists using a standard manifest refraction protocol of less than 0.25 D. This degree of interobserver repeatability is similar to that in intraobserver repeatability studies published to date and may represent the value of training and the use of a standard manifest refraction protocol between refraction observers in a refractive surgery practice involving co‐management between surgeons and optometrists. Financial Disclosure Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology, Arcscan, Inc., through patents administered by the Cornell Center for Technology Enterprise and Commercialization. No other author has a financial or proprietary interest in any material or method mentioned.

Surgically induced corneal necrotizing keratitis following LASIK in a patient with inflammatory bowel disease

We describe a case of necrotizing keratitis that developed after laser in situ keratomileusis (LASIK) in a 50-year-old woman with inflammatory bowel disease. The patient had not disclosed her history of a total colectomy for recurrent ulcerative colitis and developed bilateral stromal inflammation and corneal melting along the flap edge with ulceration within 3 days of uneventful bilateral LASIK for myopia. She was aggressively managed with topical and systemic corticosteroid therapy. Flap infiltrates gradually resolved, with no relapse during the 12-month follow-up. This case highlights the importance of taking a detailed history, specifically addressing autoimmune diseases, before corneal refractive surgery.

Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Diameter and Spherical Aberration Induction

PURPOSE To evaluate optical zone diameter efficacy and spherical aberration change in hyperopic small incision lenticule extraction (SMILE). METHODS Prospective study of 60 consecutive hyperopic SMILE procedures using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) and matched LASIK procedures with the VisuMax and MEL 80 excimer (Carl Zeiss Meditec) lasers. Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). For SMILE, the transition zone was 2 mm and the mean optical programmed zone was 6.37 mm (range: 6.3 to 6.7 mm). Two LASIK control groups (6.5- and 7-mm optical zone) matched for spherical equivalent treated were generated. Both tangential and axial curvature difference maps were generated for each eye at 3 months. A fixed grid and set of concentric circles were superimposed on the difference map to measure the achieved optical zone diameter. RESULTS Mean attempted spherical equivalent refraction was +5.58 ± 0.95 D (range: +3.20 to +6.50 D) in the SMILE group. By tangential mapping, SMILE programmed at a mean optical zone of 6.37 mm achieved a diameter of 5.03 ± 0.30 mm, similar to 7-mm LASIK (4.96 ± 0.25 mm, P = 0.33) but larger than 6.5-mm LASIK (4.53 ± 0.25 mm, P < .001). By axial mapping, the achieved optical zone diameter was 6.75 ± 0.31 mm for 6.37-mm SMILE, larger than for both 6.5-mm (6.61 ± 0.21 mm) and 7-mm (6.92 ± 0.14 mm) LASIK (P < .01). Spherical aberration changed on average by -0.45 ± 0.22 μm for 6.37-mm SMILE, similar to 7-mm LASIK (-0.50 ± 0.21 μm, P = .29) and less than for 6.5-mm LASIK (-0.69 ± 0.22 μm, P < .001). CONCLUSIONS The mean achieved optical zone diameter of hyperopic SMILE was found to be larger than the mean achieved optical zone diameter of hyperopic LASIK. Consequently, spherical aberration induction was similar for 6.37-mm SMILE and 7-mm LASIK. [J Refract Surg. 2017;33(6):370-376.].

Transitioning from mechanical microkeratome to femtosecond laser flap creation: Visual outcomes of an experienced and a novice LASIK surgeon

PURPOSE: To compare the visual outcomes of the first 200 myopic laser in situ keratomileusis (LASIK) cases between a mechanical microkeratome expert surgeon and a fellowship‐trained surgeon transitioning to the femtosecond laser. SETTING: London Vision Clinic, London, United Kingdom. DESIGN: Comparative case series. METHODS: This analysis comprised the first 200 consecutive myopic LASIK procedures using the Visumax femtosecond laser and the MEL 80 excimer laser for an expert surgeon (11 637 previous microkeratome LASIK procedures) and a fellowship‐trained surgeon (observed 1057, performed 155 supervised LASIK procedures) following a standardized surgical technique. Inclusion criteria were preoperative spherical equivalent (SE) refraction up to −8.50 diopters (D), cylinder up to 3.50 D, and corrected distance visual acuity (CDVA) of 20/20 or better. Follow‐up was 1 year. RESULTS: There were no statistically significant differences in outcome measures between surgeons. Preoperatively, the mean SE was −4.00 D ± 1.83 (SD) and −3.97 ± 1.98 D and the mean cylinder was 0.81 ± 0.67 D and 0.79 ± 0.66 D for the expert surgeon and fellowship‐trained surgeon, respectively. Postoperatively, the SE was ±0.50 D in 79% and 74%, uncorrected distance visual acuity was 20/20 or better in 96% and 96%, and 1 line of CDVA was lost in 3.5% and 1.5% for the expert surgeon and fellowship‐trained surgeon, respectively. Contrast sensitivity increased or was unchanged. CONCLUSION: A fellowship‐training program based on a standardized surgical protocol resulted in statistically comparable outcomes between an expert surgeon and a fellowship‐trained surgeon when newly transitioned to a femtosecond laser device. Financial Disclosure: Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology (Arcscan, Inc.) through patents administered by the Cornell Center for Technology Enterprise and Commercialization, Ithaca, New York, USA. No other author has a financial or proprietary interest in any material or method mentioned.

Outcomes for Myopic LASIK With the MEL 90 excimer laser.

PURPOSE To evaluate the visual outcomes of myopic LASIK performed with the MEL 90 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) using the Triple-A profile with a 500-Hz pulse rate. METHODS Retrospective analysis of the first 286 myopic LASIK procedures (147 patients) by two experienced surgeons in which the VisuMax femtosecond laser and MEL 90 excimer laser (Carl Zeiss Meditec) were used following a standardized surgical technique. Inclusion criteria were preoperative spherical equivalent refraction (SEQ) up to -10.38 diopters (D), cylinder up to 5.00 D, and corrected distance visual acuity (CDVA) of 20/25 or better. No nomogram adjustments were made. Patients were observed for 3 months. Flap thickness was between 80 and 110 µm and optical zone was between 6 and 7 mm. Standard outcomes analysis was performed. RESULTS Preoperatively, mean SEQ was -3.83 ± 1.83 D (range: -0.13 to -10.38 D) and mean cylinder was -0.94 ± 0.86 D (range: 0.00 to -5.00 D). Mean age was 36.4 years (range: 18.2 to 74.1 years) with 50% female patients. Of this population, 138 eyes were treated by one surgeon and 148 eyes by another. The mean predictability of SEQ was -0.13 ± 0.34 D (range: -1.00 to +1.00 D). Postoperative SEQ was ± 0.50 D in 88% and ± 1.00 D in 100% of eyes. Preoperative CDVA was 20/20 or better in 97% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 92% and 20/25 or better in 99% of eyes. One line of CDVA was lost in 6% of eyes and no eyes lost two or more lines. There was statistically significant improvement in mesopic contrast sensitivity (CSV-1000) at 3 (P = .021), 6, 12, and 18 (all P ≤.001) cycles per degree. CONCLUSIONS The MEL 90 excimer laser using the Triple-A ablation profile with a 500-Hz pulse rate was found to achieve a small but real increase in contrast sensitivity and high efficacy for myopia up to -10.00 D and cylinder up to 5.00 D without the need for a nomogram adjustment.

Comparison of the predictability of refractive cylinder correction by laser in situ keratomileusis in eyes with low or high ocular residual astigmatism

Purpose To compare the manifest refractive cylinder (MRC) predictability of myopic astigmatism laser in situ keratomileusis (LASIK) between eyes with low and high ocular residual astigmatism (ORA). Setting London Vision Clinic, London, United Kingdom. Design Retrospective case study. Methods The ORA was considered the vector difference between the MRC and the corneal astigmatism. The index of success (IoS), difference vector ÷ MRC, was analyzed for different groups as follows: stage 1, low ORA (ORA ÷ MRC <1), high ORA (ORA ÷ MRC ≥1); stage 2, low ORA group reduced to match the high ORA group for MRC; stage 3, grouped by ORA magnitude with low ORA (<0.50 diopters [D]), mid ORA (0.50 to 1.24 D), and high ORA (≥1.25 D); stage 4, high ORA group subdivided into low (<0.75 D) and high (≥0.75 D) corneal astigmatism. Results For stage 1, the mean preoperative MRC and mean IoS were −1.32 D ± 0.65 (SD) (range −0.55 to −3.77 D) and 0.27, respectively, for low ORA and −0.79 ± 0.20 D (range −0.56 to −2.05 D) and 0.37, respectively, for high ORA. For stage 2, the mean IoS increased to 0.32 for low ORA. For stage 3, the mean IoS was 0.28, 0.29, and 0.31 for low ORA, mid ORA, and high ORA, respectively. For stage 4, the mean IoS was 0.20 for high ORA/low corneal astigmatism and 0.35 for high ORA/high corneal astigmatism. Conclusions The MRC predictability was slightly worse in eyes with high ORA when grouped by the ORA ÷ MRC. Matching for the MRC and grouping by ORA magnitude resulted in similar predictability; however, eyes with high ORA and high corneal astigmatism were less predictable. Financial Disclosure Dr. Reinstein is a consultant to Carl Zeiss Meditec AG, has a proprietary interest in the Artemis technology (Arcscan, Inc.), and is an author of patents related to very‐high‐frequency digital ultrasound administered by the Center for Technology Licensing at Cornell University, Ithaca, New York, USA. No other author has a financial or proprietary interest in any material or method mentioned.