Mean Preoperative Spherical Equivalent Refraction Research Articles

Keratorefractive Lenticule Extraction Using the Ziemer FEMTO LDV Z8 Platform (CLEAR): One-Year Results.

To present the outcomes and detail the surgical procedure employed in the initial 102 eyes treated with keratorefractive lenticule extraction (KLEx) using the FEMTO LDV Z8 platform (Ziemer Ophthalmic Systems). This was a retrospective analysis of 102 eyes of 53 patients treated with KLEx at the American University of Beirut Medical Center. Visual, refractive, topographic, and aberrometric parameters were evaluated 1 week and 1, 3, 6, and 12 months postoperatively. Mean preoperative spherical equivalent refraction (SEQ) was -4.11 ± 1.82 diopters (D) (range: -10.00 to -1.625 D) and mean preoperative cylinder was -0.75 ± 0.65 D (range: -3.00 to 0.00 D). Postoperatively, the mean SEQ was 0.06 ± 0.54 D (range: -2.88 to +1.00 D) at 1 week and -0.04 ± 0.26 D at 12 months and was within ±0.50 D in 95.6% and ±1.00 D in 100% of eyes. A total of 96.7% of eyes had an uncorrected distance visual acuity (UDVA) of 20/20 at 12 months postoperatively. Fifty percent gained one or more lines of corrected distance visual acuity (CDVA), 5 eyes (5.4%) lost one line, and none lost two or more lines. No suction losses were encountered and all extracted lenticules were intact without tears. The application of KLEx using the FEMTO LDV Z8 platform yields safe and effective outcomes, aligning comparably with established modes of lenticule extraction and femtosecond laser-assisted laser in situ keratomileusis procedures previously employed and accepted within the field of refractive surgery. [J Refract Surg. 2024;40(11):e898-e905.].

Does the introduction of streamlight decrease refractive surgery operating time?

The aim of the study was to analyze the time-savings associated with introduction of Streamlight™ (Alcon Laboratories, Fort Worth, TX, USA) transepithelial photorefractive keratectomy (PRK) in surface corneal ablations. All refractive surgeries were performed using the Alcon WaveLight® EX500 at the ArtLife Clinic, Gdańsk, Poland. The study included patients treated for refractive errors with transepithelial PRK between April 2019 and October 2021, who were matched with patients treated with alcohol-assisted PRK during the same period. Only results for the left eye were analyzed. One-hundred-five patients underwent transepithelial PRK (age 33.42 ± 8.67years) and were matched with 105 patients that underwent alcohol-assisted PRK (age 33.05 ± 10.16years; p = 0.11). The mean preoperative spherical equivalent refraction was - 2.04 ± 2.28 D, and - 1.9 ± 1.71 D for the transepithelial and alcohol-assisted PRK group, respectively (p = 0.20). The total surgery time was non-significantly shorter in transepithelial PRK (349.46 ± 47.83s) than in alcohol-assisted PRK (354.93 ± 137.63s; p = 0.7); however, the variance of surgical time was significantly lower in transepithelial PRK (p<0.001). The laser treatment duration was greater in transepithelial PRK (41.78 ± 17.2s) than in alcohol-assisted PRK (8.48 ± 6.12s; p < 0.001), and so was the number of breaks during the laser treatment (0.95 ± 0.63 vs. 0.53 ± 0.88, respectively; p < 0.001). The introduction of transepithelial PRK did not bring significant time-associated savings into the refractive surgery suite.

Ten-Year Outcomes of LASIK for Pediatric Myopic Anisometropia.

To evaluate long-term safety, effectiveness, and stability of unilateral LASIK in pediatric myopic anisometropic amblyopia. This retrospective study included children who received unilateral LASIK for myopic anisometropia of >6 D, after mandatory 6-month occlusion/penalization therapy. They were evaluated at 6 months, 1 year, 2 years and biannually until 10 years. Outcome measures included visual acuity, refraction, ocular alignment, stereopsis, corneal clarity, and corneal topography. 32 patients (16 girls) with mean age of 8.6 ± 2.3 years completed 10 years of follow up after unilateral LASIK. Mean preoperative spherical equivalent refraction (SER) was -10.3D ±2.0D in the affected eye, with anisometropic difference of -9.5D ±1.7D. Mean post-LASIK SER was -1.3D±0.8D (p<0.001). Anisometropia significantly decreased to 0.3D±0.8D, 0.4D±1.0D, and 1.0±2.5D at 6 months, 1 year and 10 years respectively (p<0.001). 11 patients (34%) who had preoperative intermittent exotropia (< 15°) regained orthophoria in all gazes, while 5 of 10 who had constant exotropia with large angle (>30°) required strabismus surgery for ocular alignment. BCVA improved from 0.04±0.6 Decimal at baseline to 0.6 ±0.2 after LASIK and occlusion therapy (p< 0.001). Despite insignificant refractive regression in both eyes, patients have maintained orthophoria, improved stereopsis, clear cornea, and the topography showed no evidence of post-LASIK ectasia. LASIK appears safe, effective, and stable for correcting refractory pediatric myopic anisometropia, in which conventional measures fail or endanger normal visual development. Eliminating anisometropic aniseikonia consequently restores binocular vision and stereopsis which, along with amblyopia therapy, would reverse amblyopia and prevent recurrence.

Four-Year Outcomes of Small Incision Lenticule Extraction for Extreme High Myopia and Myopic Astigmatism.

Purpose: To evaluate the long-term safety, efficacy, predictability, and stability of small incision lenticule extraction (SMILE) for the treatment of high myopia and myopic astigmatism >−10.0 D.Methods: This was a prospective study that incorporated 35 consecutive patients (35 eyes) undergoing SMILE from September 2015 to March 2016. These patients had a mean preoperative spherical equivalent refraction of −10.06 ± 0.64 D. Patients were followed over a 4-year period and assessed for outcomes including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and corneal topography.Results: At 4 years post-SMILE, respective efficacy and safety indices were 1.01 ± 0.19 and 1.07 ± 0.15. In total, 97% of operated eyes achieved an UDVA of 20/25 or better. ≥1 line was gained for 9 eyes (26%), with 25 eyes (71%) remaining stable. Twenty-four (69%) and 33 (94%) eyes, respectively, were within ±0.50 D and ±1.0 D of target refraction. From 3 months to 4 years postoperatively, a mean refractive regression of −0.22 D (−0.06 D per year) was detected, whereas no significant changes in mean corneal back curvature or posterior central elevation were detected (P = 0.617 and 0.754, respectively). We detected significant increases in higher-order aberrations (HOAs) of the anterior and total cornea (all P < 0.001), with spherical aberrations and vertical coma being particularly common, whereas posterior corneal HOA remained fairly stable (all P < 0.05).Conclusion: SMILE is a safe, effective, predictable, and stable means of correcting high myopia and myopic astigmatism over a 4-year postoperative period.

Clinical outcomes of transepithelial photorefractive keratectomy versus femtosecond laser assisted keratomileusis for correction of high myopia in South Egyptian population

To evaluate the safety and efficacy of transepithelial photorefractive keratectomy (t-PRK) with adjuvant mitomycin C (MMC) versus femtosecond laser assisted keratomileusis (Femto-LASIK) in correction of high myopia. Prospective randomized comparative study including 156 eyes of 156 patients with high myopia and a spherical equivalent refraction (SER) <-6.00 D. They were divided randomly into two groups: Group A included 72 eyes treated with t-PRK with adjuvant MMC and Group B included 84 eyes treated with Femto-LASIK. Visual acuity, SER, corneal topography, pachymetry and keratometry were assessed for 12mo postoperatively. The preoperative mean SER was -8.86±1.81 and -9.25±1.70 D in t-PRK MMC group and Femto-LASIK respectively (P=0.99) which improved to -0.65±0.43 D and -0.69±0.50 D at 12mo follow up. Mean SER remained stable during the 12mo of follow-up, with no statistically significant difference between the two groups (P=0.64). In t-PRK MMC group, only six eyes needed retreatment after six months of follow up. And two eyes showed haze (one reversible haze grade 2, while the other had dense irreversible haze grade 4). t-PRK MMC provides safe and satisfactory visual outcomes and acceptable risk as Femto-LASIK in patients with high myopia.

Wavefront properties of the anterior and posterior corneal surface after transepithelial photorefractive keratectomy in myopia.

The present study aimed to evaluate the changes of corneal higher-order aberrations (HOAs) after transepithelial photorefractive keratectomy (TransPRK) in patients with myopia. A total of 80 eyes of 80 patients with myopia with or without astigmatism were evaluated. Prior to and 1 year after the surgery, uncorrected and corrected distance visual acuity in logMAR were assessed. Wavefront aberrations on the anterior surface of the cornea, as well as the posterior and total cornea, were measured via Pentacam. The HOA of the anterior surface and total values of spherical and coma aberrations increased significantly (P<0.001). However, HOAs of the anterior surface, and posterior and total values of the trefoil were not significantly changed (P=0.442, 0.805 and 0.936, respectively). A significant correlation of the pre-operative mean spherical equivalent refraction (MSER), astigmatism and central corneal ablation depth (CCAD) with the changes in coma aberration (r=0.268, P=0.016; r=0.260, P=0.020; r=0.323, P=0.004, respectively) and HOA (r=0.554, P<0.001; r=0.312, P=0.005; r=0.583, P<0.001, respectively) of the anterior surface of the cornea was determined. Furthermore, a significant correlation of the pre-operative MSER and CCAD with the changes in spherical aberration of the anterior corneal surface (r=0.462, P<0.001; r=0.510, P<0.001, respectively) was obtained. In conclusion, TransPRK offers an effective option for improving visual function in patients with myopia. The anterior corneal HOA, as well as spherical and coma aberrations, were significantly increased post-operatively. The HOA of the posterior cornea was not significantly changed. The change in the trefoil aberration was significantly correlated with pre-operative astigmatism, but the pre- and post-operative values were not significantly different.

Effect of topical pilocarpine on refractive surgery outcomes.

To investigate the effect of topical pilocarpine on topical cycloplegia and on the results of refractive surgery. The study included 100 eyes of 100 patients who underwent laser-assisted in situ keratomileusis. Group 1 comprised patients who wanted to undergo surgery on the same day after cycloplegic examination and were applied with 2% pilocarpine hydrochloride; group 2 comprised patients whose pupils spontaneously went into the natural position. Corneal thickness, mean refractive spherical equivalent (MRSE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), pupil diameter, pupil center shift and high-order aberrations (HOAs) were compared between the two groups. There were no statistically significant differences between the groups in respect of preoperative age, gender, corneal thickness, MRSE, UDVA and CDVA. The pupil diameter was not statistically significant between the groups. Pupil diameter after pilocarpine was not statistically significant when compared with the natural pupil diameter. There were no statistically significant differences in postoperative HOA between the two groups. The pupillary dilatation and the associated pupillary shift were reduced with pilocarpine. Postoperative refractive values and aberrations showed no difference between the groups.

LASIK surgery in pediatric anisometropia

Background: Refractive surgery, particularly laser in-situ keratomileusis (LASIK)surgery, at present offers hope in pediatric anisometropia, particularly where traditional therapy has failed. Studies show that it is an effective and safe procedure that corrects high anisometropia and improved binocularity, when conventional therapies had failed. The aim of the Work: to evaluate the visual outcomes of patients with anisometropic amblyopia after laser in-situ keratomileusis (LASIK) surgery. Patients and Methods: This study enrolled 20 anisometropic eyes of 20 patients ranging from 6 to 12 years with refractive difference between two eyes more than four diopters, LASIK was performed in the amblyopic eye under topical or general anaesthesia according to the cooperation of the patients. Visual acuity, refraction, corneal topography, and complications were evaluated. Results: The mean preoperative spherical equivalent refraction (SE) in the operated eye was -5.89±1.46 diopter (range: -10.00 to - 4.24D), significantly decreased down to -0.36±0.19 D at one week, -0.38±0.19 D at one month, 0.46±0.26 D at three months postoperatively. The mean uncorrected visual acuity in the operated eye was 0.58±0.13 (range: 0.30_A0.8) gained five or more lines on snellens chart. The best corrected visual acuity also shows a great improvement in comparing to the preoperative state by one or more lines three months after surgery. Conclusion: LASIK is effective, safe and predictable alternative method for correcting anisometropia in children.

LASIK surgery in pediatric anisometropia

Background: Refractive surgery, particularly laser in-situ keratomileusis (LASIK)surgery, at present offers hope in pediatric anisometropia, particularly where traditional therapy has failed. Studies show that it is an effective and safe procedure that corrects high anisometropia and improved binocularity, when conventional therapies had failed. The aim of the Work: to evaluate the visual outcomes of patients with anisometropic amblyopia after laser in-situ keratomileusis (LASIK) surgery. Patients and Methods: This study enrolled 20 anisometropic eyes of 20 patients ranging from 6 to 12 years with refractive difference between two eyes more than four diopters, LASIK was performed in the amblyopic eye under topical or general anaesthesia according to the cooperation of the patients. Visual acuity, refraction, corneal topography, and complications were evaluated. Results: The mean preoperative spherical equivalent refraction (SE) in the operated eye was -5.89±1.46 diopter (range: -10.00 to - 4.24D), significantly decreased down to -0.36±0.19 D at one week, -0.38±0.19 D at one month, 0.46±0.26 D at three months postoperatively. The mean uncorrected visual acuity in the operated eye was 0.58±0.13 (range: 0.30_A0.8) gained five or more lines on snellens chart. The best corrected visual acuity also shows a great improvement in comparing to the preoperative state by one or more lines three months after surgery. Conclusion: LASIK is effective, safe and predictable alternative method for correcting anisometropia in children.

Corneal flap thickness with the Moria M2 single-use head 90 microkeratome in 72 consecutive LASIK procedures.

PurposeThis study aimed to evaluate the accuracy and consistency of corneal flap thickness in laser-assisted in situ keratomileusis (LASIK) with the Moria M2 single-use head 90 microkeratome.MethodsThe central corneal thickness of 72 (37 right, 35 left) eyes of 37 patients was measured by ultrasonic pachymetry preoperatively and intraoperatively after flap cut. The Moria M2 single-use head 90 microkeratome was used to create a superior hinged flap in all eyes. The right eyes were always operated on before the left eyes in each patient, using the same blade in all bilateral cases. All patients underwent LASIK for myopia and/or myopic astigmatism using VISX Star S4 platform.ResultsThe mean preoperative spherical equivalent refraction was −3.55±2.30 D (range: −0.625 to −11.00 D), preoperative central corneal thickness by ultrasonic pachymetry was 541±26.82 µm (490–600 µm) and steepest K was 44.08±1.49 D (40–46.75 D) in all eyes. The mean flap thickness was 136.97±20.07 µm (106–192 µm), 131.2±19.5 µm (91–192 µm), and 134.16±19.85 µm (91–192 µm) in the right, left, and both eyes, respectively. A positive significant relationship was found between flap thickness and preoperative ultrasonic pachymetry thickness. No significant relationship was found between flap thickness and the age, preoperative spherical equivalent, and preoperative steepest K. The difference between the first and second eyes was not significant. There were no major intraoperative and postoperative complications in all eyes.ConclusionThe Moria M2 single-use head 90 microkeratome cut relatively thicker flaps than were intended. The flap thickness range was quite wide. This was a disadvantage for the accuracy and consistency of corneal flap thickness.

Cap Lenticular Adhesion During Small Incision Lenticular Extraction Surgery: Causative Factors and Outcomes.

To study the factors causing cap lenticular adhesion (CLA), a rare complication of small incision lenticule extraction (SMILE) surgery, and its effect on surgical outcomes. A prospective, observational, cross-sectional study involving 550 eyes of 285 subjects. SMILE was performed using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) with a minimum of 3 months follow-up. Preoperative visual quality assessment, measurement of corneal biomechanics, and Bowman membrane imaging were performed. Based on the mean refractive spherical equivalent (MRSE), subjects were classified into mild, moderate, and high myopes. Causes of CLA and postoperative outcomes were evaluated. CLA was seen in 1.8% of patients, in whom the median preoperative MRSE was -1.5 (-2.75 to -1.38), deformation amplitude was 1.13 (1.10 to 1.21), and lenticular thickness was 46.2 (39.9 to 54.31). They had microdistortions in the Bowman layer and poor quality of vision. A median Strehl ratio of 0.08 (0.07 to 0.11) and modulation transfer function of 9.88 (8.98 to 13.34) were noted on the first day after surgery, which gradually improved to 0.17 (0.15 to 0.18) and 33.90 (27.27 to 38.94), respectively. On observing the surgical videos, a distinct shining reflection, "the shimmer sign," was seen around the dissector in patients with CLA when the posterior plane was dissected before the anterior. Cap lenticular adhesion was associated with a low preoperative MRSE and thin lenticules. The shimmer sign serves as an indicator for identification of the correct plane of dissection.

Corneal Cross-Linking in Pediatric Patients With Progressive Keratoconus.

To evaluate corneal cross-linking (CXL) in the treatment of keratoconus in pediatric patients. Specifically, this study investigates the impact of CXL on uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), manifest refraction, keratometry (K) measurements, and higher order aberrations. This is a retrospective, observational case series of patients 18 years old or younger with progressive keratoconus who underwent CXL from January 2009 to August 2013. Preoperative and 1-year postoperative data including BDVA, manifest refraction, mean K readings, and corneal aberration measurements were extracted from clinical charts and topographical imaging. Visual acuity was converted to logarithm of the minimum angle of resolution (logMAR) scale, and mean refractive spherical equivalent (MRSE) was calculated from manifest refraction. The group consisted of 39 eyes from 28 patients, including 21 males and 7 females (mean age = 16.3 years, range: 11-18, standard deviation [SD] = 1.81). UDVA did not change significantly (preoperative UDVA = 1.20 logMAR, SD = 0.57, and postoperative UDVA = 0.90 logMAR, SD = 0.67, P = 0.19). BDVA did not change significantly (preoperative BDVA = 0.34 logMAR, SD = 0.27, and postoperative BDVA = 0.34 logMAR, SD = 0.23, P = 0.50). There was no significant change in mean K (preoperative K = 48.49, SD = 5.44, and postoperative K = 48.25, SD = 4.74, P = 0.34). Mean MRSE did not change significantly (preoperative MRSE = -3.29 D, SD = 4.04, and postoperative MRSE = -3.53 D, SD = 4.07, P = 0.31). Corneal aberration measurements were available for 10 eyes, and stability of measurements was demonstrated. There were no complications noted. This study suggests that CXL is a safe and effective procedure that halts the progression of keratoconus in pediatric patients at 1-year follow-up. To validate these findings, longer follow-up is required.

Induced Higher-order aberrations after Laser In Situ Keratomileusis (LASIK) Performed with Wavefront-Guided IntraLase Femtosecond Laser in moderate to high Astigmatism.

BackgroundWavefront-guided Laser-assisted in situ keratomileusis (LASIK) is a widespread and effective surgical treatment for myopia and astigmatic correction but whether it induces higher-order aberrations remains controversial. The study was designed to evaluate the changes in higher-order aberrations after wavefront-guided ablation with IntraLase femtosecond laser in moderate to high astigmatism.MethodsTwenty-three eyes of 15 patients with moderate to high astigmatism (mean cylinder, −3.22 ± 0.59 dioptres) aged between 19 and 35 years (mean age, 25.6 ± 4.9 years) were included in this prospective study. Subjects with cylinder ≥ 1.5 and ≤2.75 D were classified as moderate astigmatism while high astigmatism was ≥3.00 D. All patients underwent a femtosecond laser–enabled (150-kHz IntraLase iFS; Abbott Medical Optics Inc) wavefront-guided ablation. Uncorrected (UDVA), corrected (CDVA) distance visual acuity in logMAR, keratometry, central corneal thickness (CCT) and higher-order aberrations (HOAs) over a 6 mm pupil, were assessed before and 6 months, postoperatively. The relationship between postoperative change in HOA and preoperative mean spherical equivalent refraction, mean astigmatism, and postoperative CCT were tested.ResultsAt the last follow-up, the mean UDVA was increased (P < 0.0001) but CDVA remained unchanged (P = 0.48) and no eyes lost ≥2 lines of CDVA. Mean spherical equivalent refraction was reduced (P < 0.0001) and was within ±0.50 D range in 61 % of eyes. The average corneal curvature was flatter by 4 D and CCT was reduced by 83 μm (P < 0.0001, for all), postoperatively. Coma aberrations remained unchanged (P = 0.07) while the change in trefoil (P = 0.047) postoperatively, was not clinically significant. The 4th order HOAs (spherical aberration and secondary astigmatism) and the HOA root mean square (RMS) increased from −0.18 ± 0.07 μm, 0.04 ± 0.03 μm and 0.47 ± 0.11 μm, preoperatively, to 0.33 ± 0.19 μm (P = 0.004), 0.21 ± 0.09 μm (P < 0.0001) and 0.77 ± 0.27 μm (P < 0.0001), six months postoperatively. The change in spherical aberration after the procedure increased with an increase in the degree of preoperative myopia.ConclusionsWavefront-guided IntraLASIK offers a safe and effective option for vision and visual function improvement in astigmatism. Although, reduction of HOA is possible in a few eyes, spherical-like aberrations are increased in majority of the treated eyes.

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction

Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK).This prospective, nonrandomized, case–control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive results, predictability, safety, and efficacy were evaluated during the 3-month follow-up. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and mean refractive spherical equivalent (MRSE).Mean preoperative MRSE was −4.30 ± 1.72 D and −4.33 ± 1.96 D, respectively (P = 0.87). The 3-month follow-up rate was 82.1% in the tPRK group (n = 145) and 86.4% in aaPRK group (n = 90), P = 0.81. Postoperative UDVA was 20/20 or better in 97% and 94% of eyes, respectively (P = 0.45). In the tPRK and aaPRK groups, respectively, 13% and 21% of eyes lost 1 line of CDVA, and 30% and 31% gained 1 or 2 lines (P = 0.48). Mean postoperative MRSE was −0.14 ± 0.26 D in the tPRK group and −0.12 ± 0.20 D in the aaPRK group (P = 0.9). The correlation between attempted versus achieved MRSE was equally high in both groups.Single-step transepithelial PRK and conventional PRK provide very similar results 3 months postoperatively. These procedures are predictable, effective, and safe for correction of myopia and compound myopic astigmatism.

Comparison of 2 femtosecond lasers for flap creation in myopic laser in situ keratomileusis: One-year results

To compare laser in situ keratomileusis (LASIK) outcomes between 2 femtosecond lasers for flap creation in the treatment of myopia up to 1 year. University eye clinic. Prospective randomized eye-to-eye study. Consecutive myopic patients were treated with wavefront-guided LASIK. One eye had a flap created by the Intralase FS 60 kHz femtosecond laser, and the fellow eye was treated with the Intralase iFS 150 kHz femtosecond laser. Eyes were randomized according to ocular dominance. Evaluations included measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity, contrast sensitivity and wavefront aberrometry. The study enrolled 122 eyes of 61 patients. The mean preoperative spherical equivalent refraction was -4.62 diopters (D) ± 2.32 (SD) and -4.66 ± 2.30 D in the 150 kHz group and 60kHz group, respectively. Patients preferred the 150 kHz laser to the 60 kHz laser intraoperatively (52.5% versus 26.2%) (P = .005). One week postoperatively, UDVA was 20/16 or better in 85.2% in the 150 kHz group and 70.5% in the 60 kHz group; the difference was statistically significant (P<.05). At 12 months, there were no significant differences in refractive outcomes or higher-order aberrations between the 2 groups. Flap creation with the 150 kHz system and the 60 kHz system resulted in excellent LASIK outcomes. Intraoperatively, patients preferred the 150 kHz system, which yielded better UDVA in the early postoperative period. There were no significant differences at 1 year between the 2 laser systems. Proprietary or commercial disclosures are listed after the references.

Single-step transepithelial ASLA (SCHWIND) with mitomycin-C for the correction of high myopia: long term follow-up.

PurposeWe wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK) termed a SCHWIND all surface laser ablation (ASLA) versus conventional alcohol-assisted photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for the correction of higher myopia of 6.00 diopters (D) or more, in an area with high risk of haze due to high intensity of sunlight.MethodsWe used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months.ResultsIn total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was -7.9 D, -8.2 D, and -7.4 D in the ASLA (n=41), PRK (n=29), and LASIK (n=31) groups. Mean postoperative spherical equivalent at 12 months postoperatively was −0.1 (standard deviation [SD]: 0.34), −0.2 (SD: 0.59), and −0.08 (SD: 0.36) in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05). Mean logMAR (logarithm of the minimum angle of resolution) uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05), 0.06 (SD: 0.1), and 0.05 (SD: 0.09) in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01) and PRK (P=0.01) groups.ConclusionASLA (SCHWIND) tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively favorable visual acuity outcomes. There was no increased incidence of haze in the ASLA group.

Presbyopia and hyperopia treatment by Presbylasik using a central multifocal excimer laser profile with a micromonovision

AbstractPurpose To analyze the efficacity and satisfaction of treatment by hyperopic presbyopia with a new in situ keratomileusis (LASIK) procedure, Supracor( Technolas Perfect Vision).Methods This retrospective study included 58 eyes of 29 patients treated with a new central multifocal presbyLASIK with a micromonovision using the Technolas 217P excimer laser between september 2011 to september 2013. Mean patient age was 55 years (range 47 to 62 years). The mean preoperative spherical equivalent refraction was +1.3D. The main outcome measure were uncorrected distance visual acuity (UDVA) and uncorrected reading ability, aberrometry, the bump and the satisfaction of the patients.Results The mean binocular UDVA was 0.09 logMAR‐/+0.15 for distance vision and 0.22 logMAR+/‐0.11 for near vision the day postoperatively , 0.04 logMAR+/‐0.14 for distance vision and 0.17 logMAR+/‐0.12 for near vision at 1 months , 0.15 logMAR+/‐0.23 and 0.19logMAR+/‐0.18 respectively at 3 months and ‐0.02 logMAR+/‐0.06 and 0.18 logMAR +/‐0.11 respectively at 6 months. The mean bump was 2.56+/‐0.9D. The median total RMS increased from 0.30µm +/‐0.07 preoperatively to 0.46µm+/‐0.14 postoperatively (p&lt;0.01). 3 patients had a retreatment : 2 in the dominant eye to improve the UDVA of distance vision and 1 in the nondominant eye to improve near vision. 86% of patients report an independance of glasses for daily activities using near, intermediate and distance vision. 100% of patients would recommend these procedure to their friends.Conclusion Central Presbylasik with micromonovision provided a high level of independance for near, intermediate and far vision.

Comparison of 2 wavefront-guided excimer lasers for myopic laser in situ keratomileusis: One-year results

To compare laser in situ keratomileusis (LASIK) outcomes between 2 wavefront-guided excimer laser systems in the treatment of myopia. University eye clinic, Palo Alto, California, USA. Prospective comparative case series. One eye of patients was treated with the Allegretto Wave Eye-Q system (small-spot scanning laser) and the fellow eye with the Visx Star Customvue S4 IR system (variable-spot scanning laser). Evaluations included measurement of uncorrected visual acuity, corrected visual acuity, and wavefront aberrometry. One hundred eyes (50 patients) were treated. The mean preoperative spherical equivalent (SE) refraction was -3.89 diopters (D) ± 1.67 (SD) and -4.18 ± 1.73 D in the small-spot scanning laser group and variable-spot scanning laser group, respectively. There were no significant differences in preoperative higher-order aberrations (HOAs) between the groups. Twelve months postoperatively, all eyes in the small-spot scanning laser group and 92% in the variable-spot scanning laser group were within ±0.50 D of the intended correction (P = .04). At that time, the small-spot scanning laser group had significantly less spherical aberration (0.12 versus 0.15) (P = .04) and significantly less mean total higher-order root mean square (0.33 μm versus 0.40 μm) (P = .01). Subjectively, patients reported that the clarity of night and day vision was significantly better in the eye treated with the small-spot scanning laser. The predictability and self-reported clarity of vision of wavefront-guided LASIK were better with the small-spot scanning laser. Eyes treated with the small-spot scanning laser had significantly fewer HOAs.

Photorefractive Keratectomy in Young Asian Aviators with Low-Moderate Myopia

The high prevalence of myopia among Asians led the Republic of Singapore Air Force (RSAF) to introduce photorefractive keratectomy (PRK) as a means of enlarging its pilot recruitment pool at the end of 2005. This study aims to address the efficacy and safety of PRK performed on young Asian patients with low-moderate myopia, as well as audit the RSAF's corneal refractive surgery (CRS) program. This is a retrospective case series of 149 eyes of 76 consecutive patients that underwent PRK as part of the RSAF CRS program over the 5-yr period from 1 January 2006 to 31 December 2010. The median patient age was 21 yr (range, 18-26 yr) and the mean preoperative spherical equivalent (SE) refraction was -3.39 - 1.19 D. Of the patients, 96.1% were men and all were of Asian origin. At the 12-mo follow-up, 98.5% of eyes had an uncorrected distance visual acuity (UDVA) of < or = 0.00 LogMAR, 100.0% of eyes had an SE refraction of within + 0.50 D of intended correction, and 2.300% of eyes had a loss of corrected distance visual acuity (CDVA) of 0.20 LogMAR. The cumulative incidence of retreatments was 6.7% and cumulative incidence of grade II or worse corneal haze requiring retreatment was 6.0%. Refractive stability was achieved at 3 mo postsurgery. The results of this study suggest that PRK performed within the context of a stringent and structured CRS program on young Asian eyes with low-moderate myopia is both efficacious and safe, with refractive stability achieved by 3 mo.

Contralateral-eye study of surface refractive treatments: Clinical and confocal microscopy evaluation

To compare the visual and refractive outcomes and the corneal structural changes in myopic patients after surface refractive treatments (ie, photorefractive keratectomy [PRK] with adjuvant mitomycin-C [MMC] and epithelial laser in situ keratomileusis [epi-LASIK]). University of Crete, Heraklion, Crete, Greece. Prospective comparative case series. One eye of consecutive myopic patients was randomly assigned to PRK-MMC, and the fellow eye was treated with epi-LASIK. Visual and refractive outcomes and corneal confocal microscopy findings were evaluated. All patients were examined preoperatively and 1, 3, 6, 12, and 24 months postoperatively. Twenty-six eyes (13 patients) were included. The mean follow-up was 2.47 years ± 0.35 (SD) (range 1.64 to 2.93 years). In the PRK-MMC group, the mean preoperative spherical equivalent refraction was -3.84 ± 1.59 diopters (D) (range -1.5 to -8.7 D) and -0.21 ± 0.44 D (range -0.5 to 1.0 D) at the last follow-up and in the epi-LASIK group, -3.91 ± 1.48 D (range -1.5 to -8.5 D) and -0.18 ± 0.36 (range +0.5 to -0.5 D), respectively. Qualitative analysis of the subepithelial nerve plexus, haze development, and keratocyte distribution were similar in the 2 groups. There was no statistically significant difference in endothelial cell density between the groups throughout the follow-up (P>.05). Epithelial LASIK and PRK-MMC gave similar visual, refractive, and corneal structural outcomes in patients with myopia for up to 2 years postoperatively. No author has a financial or proprietary interest in any material or method mentioned.