PRESBYOND Laser Blended Vision LASIK in Commercial and Military Pilots Requiring Class 1 Medical Certification.

PURPOSE: To report the outcomes of PRESBYOND Laser Blended Vision LASIK (Carl Zeiss Meditec AG) in presbyopic commercial and military pilots requiring Class 1 aeromedical certification. METHODS: This was a retrospective study of 23 consecutive pilots who underwent PRESBYOND Laser Blended Vision LASIK. Postoperative visits were conducted at 1 day and 1, 3, and 12 months. Standard outcomes analysis was performed using the data at 12 months. Objective quality of vision measures including mesopic contrast sensitivity (CSV-1000; VectorVision), Ocular Scatter Index (HD Analyzer; Keeler), and straylight (C-Quant; Oculus Optikgeräte GmbH) were determined before and 3 months after surgery. A questionnaire to assess the functional vision of pilots before and after surgery was derived to record subjective outcomes. RESULTS: Of the 23 pilots treated, data were available at 12 months for 22 pilots (95.7%) and at 3 months for 1 pilot (4.3%). Median age was 55 years (range: 42 to 65 years). At 12 months, binocular uncorrected distance visual acuity was 20/20 or better in 100% and 20/16 or better in 52% of pilots. Binocular uncorrected intermediate visual acuity was J3 in 73%, J5 in 95%, and J10 in 100% of pilots. Binocular uncorrected near visual acuity was J1 or better in 78% and J2 or better in 100% of pilots. Mean postoperative spherical equivalent refraction relative to the target was -0.04 ± 0.34 diopters (D) (range: -0.63 to +0.63 D), with 93% within ±0.50 D. There was a statistically significant increase in contrast sensitivity at 3, 6, 12, and 18 cpd. C-Quant straylight was 1.07 ± 0.16 before surgery and 1.06 ± 0.16 at 1 to 3 months after surgery (P = .705). All pilots achieved Class 1 medical certification from the United Kingdom Civil Aviation Authority and resumed flying. All pilots reported improved functionality compared to the previous vision correction method. CONCLUSIONS: PRESBYOND Laser Blended Vision LASIK enabled presbyopic commercial pilots to continue to fly without the need for glasses. With consideration of the visually challenging cockpit environment, PRESBYOND Laser Blended Vision LASIK provides clear continuous vision for tasks at near, intermediate, and far distance. Class 1 pilots reported a subjective improvement in visual tasks and comfort following surgery. [J Refract Surg. 2023;39(1):6-14.].

Large Population Outcomes of Small Incision Lenticule Extraction in Young Myopic Patients.

PURPOSE: To evaluate the outcomes of small incision lenticule extraction (SMILE) for myopia in a large population of young adults. METHODS: In this retrospective case series, the patient population consisted of the first 4,138 consecutive SMILE treatments using the VisuMax femtosecond laser (Carl Zeiss Meditec) between 2012 and 2018 at the London Vision Clinic. Inclusion criteria were myopic spherical equivalent up to -9.00 diopters (D), cylinder up to 6.00 D, corrected distance visual acuity of 20/20 or better, age younger than 40 years, and follow-up of 12 months. Outcomes analysis was performed using the Standard Graphs for Reporting Refractive Surgery. RESULTS: Data were available at 12 months in 3,722 eyes (90%), and 416 eyes (10%) were lost to follow-up. Mean attempted spherical equivalent refraction (SEQ) was -4.61 ± 1.84 D (range: -1.12 to -9.00 D). Mean cylinder was -0.78 ± 0.66 D (range: 0.00 to -6.00 D). Postoperatively, the mean SEQ relative to target was -0.13 ± 0.30 D (range: -1.35 to +1.25 D) and was within ±0.50 D in 88.1% and ±1.00 D in 99.6% of eyes. Uncorrected distance visual acuity was 20/20 or better in 95.4% of eyes and 20/25 or better in 98.7% of eyes. One line of CDVA was lost in 3.0% of eyes, and 0.08% (n = 3) lost two or more lines of CDVA, for which CDVA was restored following phototherapeutic keratectomy treatment. There was a statistically significant improvement of 0.05, 0.06, 0.07, and 0.07 log units for contrast sensitivity at 3, 6, 12, and 18 cycles per degree, respectively (P < .001). CONCLUSIONS: SMILE achieved excellent outcomes for myopia up to -9.00 D with cylinder up to -5.50 D for a large population in patients without presbyopia. [J Refract Surg. 2022;38(8):488-496.].

Objective and Subjective Quality of Vision After SMILE for High Myopia and Astigmatism.

PURPOSE: To report subjective and objective quality of vision (QoV) results for high myopic small incision lenticule extraction (SMILE) between -9.00 and -13.00 diopters (D). METHODS: This was a prospective study recruiting 114 patients undergoing SMILE with attempted spherical equivalent refraction (SEQ) correction from -9.00 to -13.00 D, and cylinder up to 5.00 D. Patients were informed before surgery of the increased risk of QoV symptoms. Patients completed the Rasch validated QoV questionnaire. Objective QoV was assessed by corneal and whole eye aberrations, HD Analyzer Objective Scatter Index (OSI) (Keeler), and contrast sensitivity. Patient satisfaction was assessed on a scale from 0 (very dissatisfied) to 10 (very satisfied). Individual item and total Rasch-scaled scores for the three subscales (frequency, severity, and bothersomeness) of the QoV questionnaire were calculated before and 12 months after surgery. RESULTS: The mean patient satisfaction score was 9.27 ± 1.18 (range: 2 to 10), 8 or higher in 93%, and 7 or higher in 98% of patients. One patient with a satisfaction score of 2 had a simple refractive error re-treatment and then reported a satisfaction score of 10. The total mean ± standard deviation Rasch-scaled QoV score for the frequency, severity, and bothersomeness subscales before surgery was 24 ± 19, 20 ± 16, and 19 ± 18, respectively. Scores increased after surgery to 41 ± 18, 32 ± 16, and 30 ± 21, respectively (P < .001). Corneal aberrations (6 mm, OSI) increased on average by 0.39 µm for spherical aberration, 0.41 µm for coma, and 0.56 µm for higher order aberrations root mean square. OSI increased on average by 0.58. There was a small but statistically significant improvement in contrast sensitivity at 3, 6, 12, and 18 cycles per degree. There were no statistically significant correlations found between subjective scores for starbursts and objective measurements. CONCLUSIONS: Satisfaction was high following SMILE for high myopia. As expected, there was an increase in QoV symptoms, mainly glare and starbursts. The acceptance of QoV symptoms for high myopic SMILE was high, indicating that residual refractive error and visual acuity are the major drivers for patient satisfaction with appropriate preoperative informed consent. [J Refract Surg. 2022;38(7):404-413.].

Small Incision Lenticule Extraction (SMILE) for the Correction of High Myopia With Astigmatism.

PURPOSE: To report the outcomes of small incision lenticule extraction (SMILE) for high myopia between -9.00 and -14.00 diopters (D). METHODS: This was a prospective study of SMILE for high myopia using the VisuMax femtosecond laser (Carl Zeiss Meditec). Inclusion criteria were attempted spherical equivalent refraction (SEQ) between -9.00 and -14.00 D, cylinder up to 7.00 D, corrected distance visual acuity (CDVA) of 20/40 or better, age 21 years or older, and suitable for SMILE. The sub-lenticule thickness was 220 µm or greater, and the total uncut stromal thickness was 300 µm or greater. Patients were to be followed up for 1 year. Standard outcomes analysis was performed using 12-month data where available or 3-month data otherwise. RESULTS: Of 187 eyes treated, data were available at 12 months for 181 eyes (96.8%) and 3 months for 4 eyes (2.1%), and 2 eyes (1.1%) were lost to follow-up. Mean attempted SEQ was -10.55 ± 1.00 D (range: -9.00 to -12.99 D). Mean cylinder was -1.19 ± 0.83 D (range: 0.00 to -4.00 D). Preoperative CDVA was 20/20 or better in 73% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 57% and 20/25 or better in 82% of eyes. Mean SEQ relative to target was -0.22 ± 0.48 D (range: -1.63 to +1.38 D), 66% ± 0.50 D and 93% ±1.00 D. Mean SEQ 12-month change was -0.08 ± 0.34 D (range: -1.75 to +0.88 D). There was loss of one line of CDVA in 4% of eyes, and no eyes lost two or more lines. Contrast sensitivity was unchanged. Patient satisfaction was 8 or more out of 10 in 94% and 6 or more in 99% of patients. CONCLUSIONS: Outcomes of SMILE for myopia greater than -9.00 D at 3 to 12 months showed excellent efficacy, safety, stability, and predictability, with high patient satisfaction. [J Refract Surg. 2022;38(5):262-271.].

Cap recovery technique and double-edge sign during small-incision lenticule extraction.

PURPOSE: To describe a new technique for identifying the upper (cap) interface during small-incision lenticule extraction (SMILE). If the lower interface is dissected first it can be challenging to locate the cap interface and complete the lenticule separation. SETTING: London Vision Clinic, London, United Kingdom. DESIGN: Retrospective analysis. METHODS: The routine protocol was to open the primary small incision and separate the cap interface, followed by the lenticule interface. If the lenticule interface was dissected first, the modified Sinskey tip was inserted through the superior end of the incision, tangentially along the cap edge interface and then rotated anteriorly to engage the edge of the lenticule adherent to the underside of the cap. The Sinskey tip is then drawn inferiorly, creating a pocket of separation of the lenticule from the cap, enabling the dissection bulb and spatula to be used to dissect the upper interface. RESULTS: A total of 629 consecutive eyes undergoing SMILE using the VisuMax femtosecond laser were included. The routine surgical protocol (cap interface first) was followed in 88% of eyes and the lenticule interface first in 12% of eyes. The lenticule was extracted successfully in all cases. Uncorrected distance visual acuity at the 1-day postoperative visit was 20/25 or better in 81% of the cap interface first group and 86% of the lenticule interface first group. CONCLUSIONS: The visual results using this cap recovery technique were equivalent to those when a routine SMILE dissection was performed. The technique allowed surgeons to rescue more challenging cases where identifying the different interfaces was difficult. This technique meant that separating the lenticule interface first should no longer be considered a complication of SMILE.

Epithelial implantation treatment after small-incision lenticule extraction.

Two cases of epithelial implantation after small-incision lenticule extraction (SMILE) treated by Nd:YAG laser and interface sweeping are described. A 40-year-old woman and 33-year-old man underwent SMILE and subsequently were noted to have epithelial cells implanted into the surgical interface. One case was treated using Nd:YAG laser. The laser was focused to the level of the interface with an energy level of 0.3 mJ. The treatment covered the entire area of epithelial implantation. The second case was treated by opening the original SMILE incision and sweeping the residual epithelial cells from the interface followed by a washout. Both the Nd:YAG laser and interface sweeping proved to be effective in reducing or eliminating the epithelial cells from the SMILE interface. Further studies are needed to report on overall safety and efficacy of these 2 techniques.

Suction stability management in small incision lenticule extraction: incidence and outcomes of suction loss in 4000 consecutive procedures.

PURPOSE: To report the incidence and outcomes of suction loss during small incision lenticule extraction (SMILE). METHODS: The incidence of suction loss was measured over 4000 consecutive SMILE procedures and categorized by cause, the interface in which suction was lost and management (restart/continue SMILE, re-SMILE thinner cap, convert to laser in-situ keratomileusis [LASIK]). One-year outcomes were compared to the fellow eye where no suction loss occurred. RESULTS: There were 20 cases of suction loss (0.50%): during the lenticule interface in seven eyes, lenticule side cut in one eye, cap interface in nine eyes and small incision for three eyes. Small incision lenticule extraction (SMILE) was continued in seven eyes, thinner cap SMILE in four eyes, LASIK in eight eyes, and the small incision was manually completed in one eye. Suction loss was caused by a Bell's reflex in 10 eyes, fixation light tracking in six eyes, patient anxiety in two eyes, a nociceptive reflex in one eye and false suction in one eye. There was no difference in results for suction loss and fellow eyes, respectively: uncorrected distance visual acuity was 20/20 or better in 100% in both groups, spherical equivalent was within ±0.50 D in 85% and 79%, one line loss of corrected distance visual acuity in 5% and 0%, and no eyes lost two lines. CONCLUSION: Suction loss can be managed depending on the interface during which suction is lost. Treatment was completed on the same day in all instances. Visual and refractive outcomes were unaffected compared to the fellow eye in this series.

Femtosecond Laser-Assisted Small Incision Sutureless Intrastromal Lamellar Keratoplasty (SILK) for Corneal Transplantation in Keratoconus.

PURPOSE: To describe a femtosecond laser-assisted small incision sutureless intrastromal lamellar keratoplasty in an eye with severe keratoconus and report on the outcome with a 1-year follow-up. METHODS: A 20-year-old man with a history of keratoconus presented for evaluation at the Tilganga Institute of Ophthalmology, Kathmandu, Nepal. The patient had previously undergone a deep anterior lamellar keratoplasty in the left eye. Examination of the right eye revealed an uncorrected distance visual acuity (UDVA) of counting fingers with a manifest refraction of -5.00 -3.50 × 170, giving a corrected distance visual acuity (CDVA) of 20/80. Thinnest pachymetry was 425 µm and progression of both anterior and posterior corneal elevation tomography and maximum keratometry was noted compared to examination 2 years prior. The VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) was used to prepare the donor and recipient cornea. The donor graft was inserted into the recipient through the 3-mm small incision. No sutures were applied. RESULTS: At 2 weeks postoperatively, UDVA was 20/50 with a manifest refraction of -1.00 -5.00 × 145 (20/32). One year postoperatively, UDVA was 20/80 with a manifest refraction of -2.50 -3.50 × 125 (20/40-2), with the maximum keratometry decreasing from 64.08 to 56.74 diopters. CONCLUSIONS: This femtosecond laser-assisted sutureless intrastromal corneal transplantation technique may provide an option to improve the quality of vision for some patients with keratoconus, affording a simpler postoperative follow-up course compared to traditional anterior lamellar or full-thickness corneal transplantation. [J Refract Surg. 2019;35(10):663-671.].

Small Incision Lenticule Extraction (SMILE) for Hyperopia: 12-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This was a prospective study of vertex-centered hyperopic SMILE using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. A standard outcomes and stability analysis was performed for the 12-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For the 93 eyes treated, last follow-up was 12 months for 72 eyes (77%) and 3 months for 11 eyes (12%), with 10 eyes (11%) lost to follow-up. Attempted spherical equivalent refraction (SEQ) was +5.61 ± 1.21 D (range: +1.00 to +6.90 D) and cylinder was -1.01 ± 0.64 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 37), uncorrected distance visual acuity was 20/40 or better in 95% of eyes. SEQ relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D) at 3 months and -0.19 ± 0.90 D (range: -2.07 to +3.50 D) at 12 months with 53% within ±0.50 D. For 70 eyes with data at 3 and 12 months, the mean change in SEQ was -0.06 ± 0.53 D (range: -2.00 to +1.75 D) and the mean change in keratometry was -0.22 ± 0.48 D (range: -1.00 to +1.00 D). There was one line loss of corrected distance visual acuity (CDVA) in 16% of eyes and no loss of two or more lines. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 12 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. There was good refractive and topographic stability between 3 and 12 months. [J Refract Surg. 2019;35(7):442-450.].

Aborted small-incision lenticule extraction resulting from false plane creation and strategy for subsequent removal based on corneal layered pachymetry imaging.

We describe a complication of false plane creation during small-incision lenticule extraction (SMILE) and the surgical plan for subsequent lenticule removal. During a primary SMILE procedure to treat high myopia, the separator instrument entered a false lamellar plane as a result of an area of resistance caused by an area of opaque bubble layer (OBL). The procedure was aborted to avoid removing an irregular lenticule. Based on measurements of the anatomic landscape, a new inferonasal small incision was created. The lenticule was separated and removed without further incidence. The patient recovered as normal and at 6 months, the uncorrected distance visual acuity was 20/16-1. This case highlights the importance of monitoring the bubble layer creation and interface separation to avoid creating or removing an irregular lenticule. It also shows the importance of layered corneal imaging to analyze and diagnose complications as well as of aborting a procedure and planning lenticule removal at a later time if deemed appropriate.

Small Incision Lenticule Extraction for Hyperopia: 3-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This prospective study of vertex-centered hyperopic SMILE used the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/40 or better. Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. Standard outcomes analysis was performed for the 3-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For 93 eyes treated, 3-month data were available for 82 (88%). Attempted spherical equivalent refraction was +5.62 ± 1.20 D (range: +1.00 to +6.90 D) and cylinder was -0.91 ± 0.68 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 36), uncorrected distance visual acuity was 20/40 or better in 89%. Spherical equivalent refraction relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D), with 59% within ±0.50 D and 76% within ±1.00 D. There was one line loss of CDVA in 17% of eyes, and one eye lost three lines (1.2%) but recovered to one line lost at 9 months. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 3 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. Undercorrection of more than 1.00 D in 5 eyes might be partly explained by latent hyperopia in these young patients. [J Refract Surg. 2019;35(1):24-30.].

Outcomes for Hyperopic LASIK With the MEL 90® Excimer Laser.

PURPOSE: To report the outcomes of laser in situ keratomileusis (LASIK) for hyperopia using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany). METHODS: This retrospective analysis included 1,383 eyes treated by LASIK for hyperopia using the Triple-A ablation profile with the MEL 90 at London Vision Clinic, London, United Kingdom, between September 2013 and December 2016. Inclusion criteria were attempted hyperopic correction of +0.25 diopters (D) or higher and corrected distance visual acuity (CDVA) of 20/40 or better. Patients were observed for 1 year after surgery. Standard outcomes analysis was performed. RESULTS: One-year data were available for 1,350 (97%) eyes. Mean attempted spherical equivalent refraction (SEQ) was +2.77 ± 1.34 D (range: +0.13 to +6.50 D) and mean cylinder was -0.67 ± 0.66 D (range: 0.00 to -5.00 D). Mean age was 54 ± 11 years (range: 21 to 75 years), and 57% were female. Postoperative spherical equivalent was ±0.50 D in 73% and ±1.00 D in 93% of eyes. Uncorrected distance visual acuity was 20/20 or better in 75% of eyes, relative to 93% with preoperative CDVA of 20/20 or better. One line of CDVA was lost in 17% of eyes and two lines were lost in 0.6% of eyes. There was a clinically insignificant but statistically significant increase (P < .01) in contrast sensitivity at 3 and 6 cycles per degree (cpd) and no change for 12 and 18 cpd. CONCLUSIONS: LASIK for hyperopia with the MEL 90 excimer laser was found to satisfy accepted criteria for safety, efficacy, and stability. [J Refract Surg. 2018;34(12):799-808.].

Suction Stability Management in SMILE: Development of a Decision Tree for Managing Eye Movements and Suction Loss.

PURPOSE: To develop a comprehensive protocol for suction stability management during small incision lenticule extraction (SMILE). METHODS: This was a retrospective video review of all SMILE cases where suction loss occurred or eye movement was noted in the medical record. The different types of eye movement were collated. A suction stability grading scale was derived to represent the magnitude of eye movements. A decision tree protocol was developed to define the management in each scenario depending on the suction stability grading and the femtosecond laser cutting progress. RESULTS: Eight types of eye movement were identified: fixation light tracking, Bell's reflex, saccades, oscillations, anxiety/uncooperative patient, nociceptive reflex movement, false suction, and nystagmus. Type I eye movements were defined as small movements that shift the corneal position by a clinically negligible amount. The surgeon may want to pause the femtosecond laser cutting, regain control of the patient, then continue. Type II eye movements were defined as large movements that shift the corneal position by a clinically relevant amount, in which case the surgeon may choose to release suction (ie, a surgeon-initiated suction loss). Type III eye movements were defined as those with sufficient force to break suction (ie, a patient-generated suction loss). A comprehensive decision tree was developed to cover all possible eye movement and suction loss scenarios. Example scenarios outside the preprogrammed machine restart treatment module include converting to laser in situ keratomileusis (LASIK) if there was tracking of the interface and restarting SMILE with a thinner cap if the original cap thickness was 135 µm or greater. CONCLUSIONS: With appropriate management, it is possible for the SMILE procedure to be completed on the same day by either continuing with SMILE or converting to LASIK depending on the progress of the femtosecond laser cutting. [J Refract Surg. 2018;34(12):809-816.].

Incidence and Outcomes of Sterile Multifocal Inflammatory Keratitis and Diffuse Lamellar Keratitis After SMILE.

PURPOSE: To report the incidence outcomes of sterile multifocal inflammatory keratitis and diffuse lamellar keratitis (DLK) after small incision lenticule extraction (SMILE) in a large population. METHODS: This was a retrospective review of a population of 4,000 consecutive eyes treated by SMILE at the London Vision Clinic using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). The inclusion criterion was to have presented with inflammatory keratitis after SMILE. In some cases after SMILE, the inflammatory keratitis presented as sterile multifocal interface keratitis uncharacteristic of classic DLK. The incidence was measured and categorized as primary or secondary by presenting appearance, grade, and time to presentation. Patients were observed for 1 year after surgery and standard outcomes analysis was performed. RESULTS: Of the 4,000 eye population, there were 18 cases (0.45%) of DLK grade 1 or 2. All cases were managed and resolved with topical steroid therapy. Of these, 12 cases (67%) were of classic appearance and 6 cases (33%) presented as sterile multifocal inflammatory keratitis. DLK was primary in nature in 11 cases (61%) and secondary in 7 cases (39%). Postoperative uncorrected distance visual acuity was 20/20 or better in 93% of eyes. No patients lost any lines of corrected distance visual acuity and there was no change in contrast sensitivity. CONCLUSIONS: DLK occurred after SMILE with an incidence of 0.45% in this population. Topical steroid therapy resolved the DLK in all cases with no sequelae and no adverse effect on refractive or visual outcome at 1 year postoperatively. A unique type of DLK presentation can occur after SMILE, characterized by multiple focal sterile inflammatory spots. Management is the same as for classic DLK, but with a lower threshold for performing an interface washout. [J Refract Surg. 2018;34(11):751-759.].

Inferior pseudo-hinge fulcrum technique and intraoperative complications of laser in situ keratomileusis retreatment after small-incision lenticule extraction.

PURPOSE: To describe the evolution of a flap-lift technique for laser in situ keratomileusis (LASIK) retreatment after small-incision lenticule extraction (SMILE) and report the incidence of complications. SETTING: London Vision Clinic, London, United Kingdom. DESIGN: Retrospective case series. METHODS: All retreatments between September 2013 and January 2017 were included. A bimanual inferior pseudo-hinge fulcrum flap-lift technique was developed to minimize the chance of tearing or entering the small incision. A flap lifter and a McPherson forceps were inserted into the inferior one third of the flap, slightly angled up to avoid perforating the small-incision lenticule extraction interface. One instrument provided countertraction, and the second separated the interface superiorly, keeping the tip away from the incision. One instrument was held against the hinge for the second instrument to separate the inferior one third. The incidence of intraoperative complications was analyzed. RESULTS: The study evaluated 162 retreatments (4.12%) for 3933 small-incision lenticule extraction treatments (1-year maturity). The retreatment was LASIK (n = 135), side-cut only (n = 1), cap-to-flap procedure (CIRCLE) (n = 3), or photorefractive keratectomy (n = 23). Two eyes (1.4%) had a tear to the small incision. The small-incision lenticule extraction interface was accessed in 8 eyes (5.8%), 1 (0.7%) centrally, and the interface was lifted in 1 eye (0.7%). There were no complications in the last 84 consecutive procedures (60%) using the finalized technique. CONCLUSION: The bimanual inferior pseudo-hinge fulcrum decreased the risk for accessing the small-incision lenticule extraction interface or tearing the small incision.

Outcomes for Mixed Cylinder LASIK With the MEL 90® Excimer Laser.

PURPOSE: To report the outcomes of LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany). METHODS: This was a retrospective analysis of all eyes treated by LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 laser between July 2013 and October 2016. Patients were observed for 1 year after surgery. Standard outcomes analysis and vector analysis by the Alpins method were performed. RESULTS: The database review identified 105 eyes (82 patients) treated by LASIK for mixed cylinder using the MEL 90 laser. Mean age was 40 ± 11 years (range: 18 to 65 years). Mean attempted spherical equivalent was +0.30 ± 0.90 diopters (D) (range: -2.30 to +1.75 D). Mean cylinder was -2.93 ± 1.47 D (range: -0.75 to -7.00 D). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 81% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 69% and 20/25 or better in 86% of eyes. Mean postoperative spherical equivalent relative to the intended target was -0.21 ± 0.38 D (range: -1.25 to +1.13 D), with 83% within ±0.50 D. Mean postoperative cylinder was -0.57 ± 0.41 D (range: 0.00 to -1.75 D). Geometric mean was 1.12 for the correction index and 0.25 for the index of success. For angle of error, the arithmetic mean was -0.6° ± 4.2° (range: -13.5° to 9.5°) and the absolute mean was 2.9° ± 3.0° (range: 0.0° to 13.5°). There was loss of one line of CDVA in 3% of eyes and no eyes lost two or more lines CDVA. There was a small increase in contrast sensitivity after surgery at 3, 6, 12, and 18 cycles per degree (P < .05). CONCLUSIONS: One-year outcomes of LASIK using the MEL 90 laser for mixed cylinder up to -7.00 D demonstrated excellent efficacy, safety, and predictability. Vector analysis found a 12% overcorrection in magnitude of refractive cylinder. Given the high accuracy for angle of error, a nomogram could be applied to reduce the over-correction and further improve the uncorrected distance visual acuity outcomes. [J Refract Surg. 2018;34(10):672-680.].

Outcomes of Re-treatment by LASIK After SMILE.

PURPOSE: To report the outcomes of LASIK re-treatments after small incision lenticule extraction (SMILE). METHODS: Retrospective review of all eyes to have undergone a re-treatment by LASIK after primary SMILE between September 2013 and January 2016. Thin-flap LASIK was used in most cases as long as sufficient tissue was available for safe flap creation between the maximum epithelial thickness and minimum cap thickness. Otherwise, the SMILE interface was converted into a LASIK flap by the Circle technique or side cut only. The multivariate nomogram for LASIK re-treatments was used, including sphere, cylinder, age, and primary spherical equivalent (SEQ) as variables. Patients were observed for 1 year after surgery and standard outcomes analysis was performed. RESULTS: A total of 116 LASIK re-treatments were performed in a population of 2,643 consecutive SMILE procedures, indicating a re-treatment rate of 4.39%. Mean attempted SEQ was -0.05 ± 0.99 diopters (D) (range: -1.88 to +1.50 D). Mean cylinder was -0.70 ± 0.55 D (range: 0.00 to -2.25 D). Postoperative uncorrected distance visual acuity was 20/20 or better in 81% of eyes, for a population with corrected distance visual acuity (CDVA) of 20/20 or better in 95% before re-treatment. Mean postoperative SEQ relative to the target was +0.19 ± 0.49 D (range: -0.88 to +2.13 D), with 74% within ±0.50 D. Mean postoperative cylinder was -0.29 ± 0.24 D (range: 0.00 to -1.25 D). There was one line loss of CDVA in 15% of eyes, but no eyes lost two or more lines. There was a small increase in contrast sensitivity (P < .05). Overcorrection was identified in myopic re-treatments (n = 20) of -1.00 D or more; mean postoperative SEQ was +0.59 ± 0.64 D (range: -0.63 to +2.13 D). CONCLUSIONS: Re-treatment after SMILE by LASIK achieved excellent visual and refractive outcomes, although these results indicate that myopic LASIK retreatment after primary myopic SMILE requires a different nomogram than for myopic LASIK re-treatment after primary myopic LASIK. [J Refract Surg. 2018;34(9):578-588.].

Role of laser refractive surgery in cross-subsidization of nonprofit humanitarian eyecare and the burden of uncorrected refractive error in Nepal: Pilot project.

PURPOSE: To establish a refractive surgery unit at Tilganga Institute of Ophthalmology through support from international donations and provide knowledge transfer for doctors and management to make the unit self-sustaining, nonprofit laser refractive surgery, and financial support for other eyecare projects at Tilganga. SETTING: Tilganga Institute of Ophthalmology, Kathmandu, Nepal. DESIGN: Retrospective study. METHODS: A foundation was created to establish a refractive surgery unit using a cost-recovery model; that is, patients are charged according to their financial status to cover running costs, patients without funds to pay for surgery, and other eyecare projects for the underprivileged population of Kathmandu, Nepal. Donations were obtained to fund refurbishment within Tilganga Hospital and purchase equipment and technology. A Nepalese surgeon was selected from Tilganga and completed an 8-month fellowship and proctorship of the first series of surgeries. The refractive surgery unit was opened in January 2012, and the cost-recovery model was evaluated up to December 2016. RESULTS: During the period evaluated, 74.8% of patients were treated at full cost, 17.2% at subsidized cost, and 8.6% free of charge. The refractive surgery unit generated a profit representing 28% of the running cost in this period, which was used to reduce the deficit of the main hospital. Surgical outcomes achieved were comparable to those reported by groups in the developed world. CONCLUSION: A self-sustaining nonprofit laser refractive surgery clinic, operating with high quality, was successfully implemented supported by international donations for initial setup costs and a cost-recovery model thereafter.

Incidence and Outcomes of Optical Zone Enlargement and Recentration After Previous Myopic LASIK by Topography-Guided Custom Ablation.

PURPOSE: To report the incidence, visual and refractive outcomes, optical zone enlargement, and recentration using topography-guided CRS-Master TOSCA II software with the MEL 80 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) after primary myopic laser refractive surgery. METHODS: Retrospective analysis of 73 eyes (40 patients) with complaints of night vision disturbances due to either a decentration or small optical zone following a primary myopic laser refractive surgery procedure using the MEL 80 laser. Multiple ATLAS topography scans were imported into the CRS-Master software for topography-guided ablation planning. The topography-guided re-treatment procedure was performed as either a LASIK flap lift, a new LASIK flap, a side cut only, or photorefractive keratectomy. Axial curvature maps were analyzed using a fixed grid and set of concentric circles superimposed to measure the topographic optical zone diameter and centration. Follow-up was 12 months. RESULTS: The incidence of use in the population of myopic treatments during the study period was 0.79% (73 of 9,249). The optical zone diameter was increased by 11% from a mean of 5.65 to 6.32 mm, with a maximum change of 2 mm in one case. Topographic decentration was reduced by 64% from a mean of 0.58 to 0.21 mm. There was a 44% reduction in spherical aberration, 53% reduction in coma, and 39% reduction in total higher order aberrations. A subjective improvement in night vision symptoms was reported by 93%. Regarding efficacy, 82% of eyes reached 20/20 and 100% reached 20/32 (preoperative CDVA was 20/20 or better in 90%). Regarding safety, no eyes lost two lines of CDVA and 27% gained one line. Regarding predictability, 71% of re-treatments were within ±0.50 diopters. CONCLUSIONS: Topography-guided ablation was effective in enlarging the optical zone, recentering the optical zone, and reducing higher order aberrations. Topography-guided custom ablation appears to be an effective method for re-treatment procedures of symptomatic patients after myopic LASIK. [J Refract Surg. 2018;34(2):121-130.].

Repair of Irregularly Irregular Astigmatism by Transepithelial Phototherapeutic Keratectomy.

PURPOSE: To evaluate the outcome of transepithelial phototherapeutic keratectomy (PTK) in the management of irregularly irregular astigmatism. METHODS: This was a case series of two patients who underwent transepithelial PTK for irregularly irregular astigmatism. In the first case, the patient complained of diplopia due to corneal scarring caused by a metallic foreign body injury. The topography demonstrated irregularly irregular astigmatism with significant asymmetry in the inferotemporal to superonasal axis. In the second case, the patient complained of blurred vision and ghosting caused by significant central epithelial ingrowth through a buttonhole LASIK flap, which was causing a localized irregularity on topography. Due to the localized nature of the irregularities, a transepithelial PTK treatment was preferred to custom ablation given the degree of epithelial masking present. RESULTS: Transepithelial PTK was performed in both cases using the Schwind Amaris 500E excimer laser (Schwind eye-tech-solutions, Kleinostheim, Germany) and an 8-mm optical zone. The ablation depth was planned to reach the depth of the epithelium using a stepwise protocol, reviewing the pattern of the remaining epithelium and regularity of the stromal surface between each ablation. A marked improvement in the regularity of the topography was achieved in both cases, with only regular astigmatism remaining. Both patients reported a subjective improvement in quality of vision and the corrected distance visual acuity improved by one and two lines, respectively. CONCLUSIONS: Transepithelial PTK was effective in treating these cases of localized irregularly irregular astigmatism, achieving both objective and subjective improvement in vision. Compensatory epithelial remodeling over the irregularities enabled the transepithelial PTK approach to target the stromal surface irregularities. [J Refract Surg. 2017;33(10):714-719.].