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AIMS: To investigate the concordance between the corneal power determined by various approaches with two tomographers (MS-39® and Galilei G6®) and the clinical history method (CHM) in patients undergoing photorefractive surgery with excimer laser for myopic errors. MATERIAL AND METHODS: Prospective cohort study. Patients undergoing keratorefractive surgery, and having pre- and postoperative keratometries, and tomographies, were included. RESULTS: In 90 eyes, the differences in the power estimated by the CHM and the one determined by four approaches with the corneal tomographers, which included measurements of the posterior cornea, did not show statistically significant differences in their averages. However, the 95% limits of agreement were very wide. After obtaining regression formulas to adjust the values of these four variables, the results of the agreement analysis were similar. CONCLUSION: Although certain values either directly determined or derived from measurements with the Galilei® and MS-39®corneal tomographers, approximated the estimated value of postoperative corneal power according to the CHM, due to the amplitude of their limits of agreement, these calculations must be taken with care, because they may not be accurate in a given eye.
Subject(s)
Cornea , Myopia , Humans , Cornea/diagnostic imaging , Cornea/surgery , Cornea/pathology , Cornea/physiopathology , Myopia/surgery , Myopia/physiopathology , Myopia/diagnostic imaging , Adult , Prospective Studies , Male , Female , Photorefractive Keratectomy , Young Adult , Corneal Topography , Lasers, Excimer/therapeutic use , Refraction, OcularABSTRACT
PURPOSE: To identify potential risk factors that increase the likelihood of re-treatment following keratorefractive lenticule extraction (KLEx) for myopia and myopic astigmatism. METHODS: This was a retrospective study of patients with myopia and myopic astigmatism who underwent KLEx using the VisuMax 500 laser (Carl Zeiss Meditec) between April 2015 and December 2020. Patients were assigned to one of two groups: the control group and the re-treatment group (if they had additional refractive surgery within 2 years of the primary treatment). The effect of different preoperative, intraoperative, and postoperative parameters on the re-treatment rate was analyzed. RESULTS: Overall 1,822 eyes of 938 patients were analyzed. In total, 2.96% of eyes (n = 54) underwent re-treatment. The re-treated patients were more likely to be women and have high myopia, high astigmatism, steep corneas, higher ocular residual astigmatism, and residual myopic and/or astigmatic refractive error. In contrast, no significant correlation was found between re-treatment rate and age, chord µ, type of astigmatism, and corneal thickness. CONCLUSIONS: Factors associated with higher rates of retreatment after KLEx included female gender, manifest refractive high myopia (> -5.00 diopters [D]), astigmatism (> 2.00 D), spherical equivalent (> 6.00 D), ocular residual astigmatism, steeper corneas, and postoperative residual myopic and astigmatic refractive errors. This study may help to preoperatively detect patients at risk for re-treatment, improve preoperative patient counseling, and optimize patient selection to reduce future re-treatment rates. [J Refract Surg. 2024;40(6):e362-e370.].
Subject(s)
Astigmatism , Lasers, Excimer , Myopia , Refraction, Ocular , Reoperation , Visual Acuity , Humans , Retrospective Studies , Male , Astigmatism/surgery , Astigmatism/physiopathology , Female , Adult , Risk Factors , Myopia/surgery , Myopia/physiopathology , Visual Acuity/physiology , Refraction, Ocular/physiology , Lasers, Excimer/therapeutic use , Young Adult , Corneal Stroma/surgery , Corneal Topography , Middle Aged , Adolescent , Corneal Surgery, Laser/methodsABSTRACT
PURPOSE: To evaluate moderate to high astigmatism corrections on the outcomes of SmartSight lenticule extraction for myopic astigmatism with a new femtosecond laser system. METHODS: Two hundred ninety-two eyes consecutively treated for myopic astigmatism with astigmatism magnitude greater than 1.00 diopter (D) were evaluated at the 6-month follow-up visit. The mean age of the patients was 29 ± 6 years with a mean spherical equivalent of -5.06 ± 2.20 diopters (D) and a mean magnitude of refractive astigmatism of 1.74 ± 0.61 D. RESULTS: At 6 months, astigmatism was 0.10 ± 0.20 D. Uncorrected and corrected distance visual acuities (UDVA and CDVA, respectively) were both 0.0 ± 0.1 logMAR. Differences between postoperative UDVA and preoperative CDVA and the change in CDVA were both +0.4 ± 0.7 lines better than preoperatively (P < .0003). CONCLUSIONS: Lenticule extraction treatment using Smart-Sight is safe and efficacious at 6 months. Findings suggest that moderate to high astigmatism improves after SmartSight lenticule extraction in the treatment of myopic astigmatism. [J Refract Surg. 2024;40(5):e328-e335.].
Subject(s)
Astigmatism , Corneal Stroma , Lasers, Excimer , Myopia , Refraction, Ocular , Visual Acuity , Humans , Astigmatism/physiopathology , Astigmatism/surgery , Visual Acuity/physiology , Retrospective Studies , Adult , Refraction, Ocular/physiology , Male , Female , Myopia/surgery , Myopia/physiopathology , Young Adult , Corneal Stroma/surgery , Lasers, Excimer/therapeutic use , Corneal Topography , Follow-Up Studies , Treatment Outcome , Corneal Surgery, Laser/methodsABSTRACT
PURPOSE: To assess the predictability between the SCHWIND ATOS femtosecond laser (SCHWIND eye-tech-solutions) read-out and achieved lenticule thickness measured using MS-39 anterior segment optical coherence tomography (ASOCT; CSO) at the corneal vertex at postoperative 1 day and 1 and 3 months of follow-up. METHODS: This retrospective case series included 130 eyes of 65 consecutive patients who were treated with SmartSight (SCHWIND eye-tech-solutions) lenticule extraction. Sixty-four percent of patients were women with a mean spherical refraction of -4.98 ± 1.19 diopters (D) and mean astigmatism of 0.53 ± 0.64 D. The measurements were performed using AS-OCT with the Phoenix Software v 4.1.1.5. Lenticule thickness was obtained by the subtraction method between preoperative and postoperative total corneal thickness. RESULTS: A lower reduction in central corneal thickness (CCT) compared to the laser read-out for all three follow-up visits can be observed. Essentially, the reduction in CCT was identical at 3 months versus 1 month. The reduction in CCT was lowest at postoperative 1 day. Examining the 1- and 3-month data (essentially equivalent), one can see a best fit of y = 0.94 x -7 µm. CONCLUSIONS: The reduction in CCT was stable from 1 month of follow-up. The stable reduction in CCT was -6% (-1.5% after accounting for design decisions) and -7 µm lower than the respective laser read-out. The findings are predictable, showing a certain level of the lenticules becoming slightly thinner than their respective laser read-outs. [J Refract Surg. 2023;39(11):728-735.].
Subject(s)
Corneal Surgery, Laser , Myopia , Humans , Female , Male , Visual Acuity , Corneal Stroma/surgery , Retrospective Studies , Lasers, Excimer/therapeutic use , Refraction, Ocular , Myopia/surgery , Corneal Surgery, Laser/methodsABSTRACT
A simple and novel method to analyse the centration of a lenticule of tissue extracted from a cornea has been developed, in which the centre of "mass" of the individual differences between post and preoperative maps of several corneal metrics represents the lenticule centration and its spatial distance to a reference point (aimed centration) determines the decentration. Different parameters have been evaluated to weight the centre of "mass". The robustness of the methods has been evaluated using perturbation analysis (adding white-noise to the data) based on realistic uncertainties. A clipped analysis has been performed to prevent large, localised areas of lacking/missing data from affecting the centre of "mass". The method has been tested on a pilot cohort of clinical data showing 30% and 63% of the treatments within 200 µm of decentration for corneal thickness and refractive equivalent power, respectively. Except for anterior elevation with a total standard deviation of 17 µm, all other metrics show excellent precision of â¼5 µm. The method provides a reliable and objective way to determine the centration of a lenticule of tissue extracted from a cornea and it can be applied to any topo- or tomographic derived metric.
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BACKGROUND: Impact of low energy asymmetric spacings vs. high energy symmetric spacings on the immediate/early (postoperative day 1 (POD1)) outcomes of SmartSight lenticule extraction for myopic astigmatism with a new femtosecond laser system. METHODS: The first 112 eyes of 56 patients consecutively treated using low energy asymmetric spacings (Group A; Study group) were compared at POD1 to the last 112 eyes of 56 patients consecutively treated using high energy symmetric spacings (Group S; Controls). Mean age of the patients was 28 ± 5 years with a mean spherical equivalent of -4.41 ± 1.76 diopters (D) and a mean magnitude of refractive astigmatism of 0.89 ± 0.82 D. RESULTS: Laser Energy was -25 ± 1nJ lower for asymmetric treatments (p < .0001); Spot and Track distances were + 0.7 ± 0.1 µm larger and -0.8 ± 0.1 µm tighter for asymmetric treatments, respectively (p < .0001 for both). At POD1, astigmatism was -0.08 ± 0.02D lower for asymmetric treatments (p < .0003); uncorrected and corrected visual acuities (UDVA and CDVA, respectively) were -0.03 ± 0.01logMAR better for asymmetric treatments (p < .0007); differences between postop UDVA and preop CDVA along with change in CDVA were + 0.3 ± 0.1lines better for asymmetric treatments (p < .0003). CONCLUSIONS: Lenticule extraction treatment using SmartSight is safe and efficacious already at POD1. Findings suggest that low energy asymmetric spacings may further improve the immediate and short-term outcomes of SmartSight lenticule extraction in the treatment of myopic astigmatism compared to conventional settings (high energy symmetric spacings).
Subject(s)
Astigmatism , Corneal Surgery, Laser , Myopia , Humans , Young Adult , Adult , Astigmatism/surgery , Visual Acuity , Retrospective Studies , Myopia/surgery , Treatment Outcome , Microsurgery , Lasers, Excimer/therapeutic use , Refraction, Ocular , Cornea/surgery , Corneal Stroma/surgeryABSTRACT
BACKGROUND: To evaluate vision 3 months after SmartSight lenticule extraction treatments. DESIGN: Case series. METHODS: This case series of patients were treated at Specialty Eye Hospital Svjetlost in Zagreb, Croatia. Sixty eyes of 31 patients consecutively treated with SmartSight lenticule extraction were assessed. The mean age of the patients was 33 ± 6 years (range 23-45 years) at the time of treatment with a mean spherical equivalent refraction of -5.10 ± 1.35 D and mean astigmatism of 0.46 ± 0.36 D. Monocular corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA) were assessed pre- and post-operatively. Ocular and corneal wavefront aberrations have been postoperatively compared to the preoperative baseline values. Changes in ocular wavefront refraction, as well as changes in keratometric readings are reported. RESULTS: At 3 months post-operatively, mean UDVA was 20/20 ± 2. Spherical equivalent showed a low myopic residual refraction of -0.37 ± 0.58 D with refractive astigmatism of 0.46 ± 0.26 D postoperatively. There was a slight improvement of 0.1 Snellen lines at 3-months follow-up. Compared to the preoperative status, ocular aberrations (at 6 mm diameter) did not change at 3 months follow-up; whereas corneal aberrations increased (+0.22 ± 0.21 µm for coma; +0.17 ± 0.19 µm for spherical aberration; and +0.32 ± 0.26 µm for HOA-RMS). The same correction was determined using changes in ocular wavefront refraction, as well as changes in keratometric readings. CONCLUSION: Lenticule extraction after SmartSight is safe and efficacious in the first 3 months postoperatively. The post-operative outcomes indicate improvements in vision.
Subject(s)
Astigmatism , Corneal Wavefront Aberration , Humans , Young Adult , Adult , Middle Aged , Astigmatism/surgery , Corneal Topography , Treatment Outcome , Lasers, Excimer/therapeutic use , Refraction, Ocular , Corneal Wavefront Aberration/surgery , Corneal StromaABSTRACT
BACKGROUND: In eyes with hyperopia, astigmatism, and mixed astigmatism Transepithelial photorefractive keratectomy (TransPRK) is a modality of surface ablation surgery. We center on the corneal vertex for all our treatments (all have an offset to the center of the pupil) and wanted to compare the visual results of symmetrical profile treatments versus asymmetrical profile treatments (the center of the treatment on the vertex and the boundaries with the pupil center) using TransPRK as corneal refractive surgery. METHODS: We retrospectively analyzed two consecutive groups of eyes treated with TransPRK in the Aurelios Augenlaserzentrum Recklinghausen: 47 eyes treated with symmetrical offset and 51 eyes treated with asymmetrical offset. The intergroup comparisons were assessed using unpaired Student's T-tests, whereas preoperative to postoperative changes were assessed using paired Student's T-tests. RESULTS: Refractive outcomes were good for both groups. 83 and 88% of eyes were within the spherical equivalent of 0.5 D from the target in the symmetric and asymmetric offset groups, respectively. 85 and 84% of eyes had a postoperative astigmatism of 0.5 D or lower in the symmetric and asymmetric offset groups, respectively. CONCLUSION: We have not found a significant difference in the refractive outcomes between the symmetric group and the asymmetric group of eyes treated both with TransPRK for preoperatively hyperopic or mixed astigmatism.
Subject(s)
Astigmatism , Hyperopia , Photorefractive Keratectomy , Humans , Astigmatism/surgery , Visual Acuity , Lasers, Excimer/therapeutic use , Retrospective Studies , Refraction, Ocular , Photorefractive Keratectomy/methods , Hyperopia/surgery , Treatment OutcomeABSTRACT
PURPOSE: To evaluate the long-term visual and refractive outcomes of hyperopic excimer ablation using alcohol-assisted photorefractive keratectomy (PRK) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). SETTING: American University of Beirut Medical Center, Beirut, Lebanon. DESIGN: Retrospective, matched comparative study. METHODS: Eyes that underwent alcohol-assisted PRK were compared to matched eyes that underwent FS-LASIK. All patients were followed up for at least 3 years after surgery. The refractive and visual outcomes of each group were compared at different postoperative time points. The main outcome measures were spherical equivalent deviation from target (SEDT), manifest refraction, and visual acuity. RESULTS: 83 eyes underwent alcohol-assisted PRK and 83 matched eyes underwent FS-LASIK. Preoperative manifest refraction spherical equivalent was 2.44 ± 1.18 diopters (D) and 2.20 ± 0.87 D ( P = .133) in the PRK and FS-LASIK groups, respectively. Preoperative manifest cylinder was -0.77 ± 0.89 D and -0.61 ± 0.59 D ( P = .175) for the PRK and LASIK groups, respectively. 3 years postoperatively, SEDT was 0.28 ± 0.66 D and 0.40 ± 0.56 D for the PRK and LASIK groups, respectively ( P = .222), whereas manifest cylinder was -0.55 ± 0.49 D and -0.30 ± 0.34 D for PRK and LASIK, respectively ( P < .001). The mean difference vector was 0.59 ± 0.46 for PRK and 0.38 ± 0.32 for LASIK ( P < .001). 13.3% of PRK eyes and 0% of LASIK eyes had >1 D of manifest cylinder ( P = .003). CONCLUSIONS: Both alcohol-assisted PRK and FS-LASIK are safe and effective for the treatment of hyperopia. PRK induces slightly more postoperative astigmatism than LASIK. Larger optical zones and recently introduced ablation profiles that lead to a smoother ablation surface might improve the clinical results of hyperopic PRK.
Subject(s)
Hyperopia , Keratomileusis, Laser In Situ , Photorefractive Keratectomy , Humans , Photorefractive Keratectomy/methods , Keratomileusis, Laser In Situ/methods , Hyperopia/surgery , Retrospective Studies , Lasers, Excimer/therapeutic use , Refraction, Ocular , Cornea/surgery , Treatment OutcomeABSTRACT
BACKGROUND: To evaluate the 12-month refractive and visual outcomes of Small Incision Guided Human-cornea Treatment (SmartSight®, SCHWIND eye-tech-solutions, Kleinostheim, Germany) in the treatment of myopia corrections with low to moderate astigmatism with the use of a new femtosecond laser system. METHODS: 221 eyes of 114 patients consecutively treated with SmartSight lenticule extraction were assessed. The mean age of the patients was 28±6 years at the time of treatment with a mean spherical equivalent refraction of -6.26±2.17D and mean astigmatism of 0.92±0.68D. Monocular corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA) were assessed pre- and post-operatively. Refractive changes have been determined in terms of changes in refraction, as well as changes in keratometric readings. The changes in central epithelial thickness have been determined. RESULTS: At twelve months post-operatively, mean UDVA was 20/21±2. Spherical equivalent showed a residual refraction of +0.48±0.31D with refractive astigmatism of 0.13±0.18D postoperatively. There was a slight decrease of -0.1 Snellen lines at 12-months follow-up. The same correction was determined using changes in refraction, as well as changes in keratometric readings. The central epithelial thickness increased by +3±2µm. Spherical equivalent correction within ±0.50D was achieved in 199 eyes (90%), and cylindrical correction in 221 (100%). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 213 eyes (96%), and postoperative uncorrected (UDVA) was 20/20 or better in 205 eyes (93%). No eye had lost two or more Snellen lines of CDVA. CONCLUSIONS: Myopic astigmatism correction with SmartSight provided good results for efficacy, safety, predictability, and visual outcomes at the twelve months of follow up. The central epithelial thickness barely increased by 3±2µm.
Subject(s)
Astigmatism , Myopia , Humans , Young Adult , Adult , Astigmatism/surgery , Treatment Outcome , Lasers, Excimer , Refraction, Ocular , Visual Acuity , Myopia/surgery , Corneal Stroma/surgeryABSTRACT
PURPOSE: To analyze the 6-month outcomes of the treatment combination of the monocular bi-aspheric ablation profile (PresbyMAX) and contralateral aspheric monofocal laser in situ keratomileusis (LASIK) ablation profile for correction of myopia and presbyopia. SETTING: Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. DESIGN: Retrospective case series. METHODS: This was a retrospective case review of 92 patients (184 eyes) diagnosed with myopia who underwent uneventful simultaneous bi-aspheric ablation in the nondominant eye and aspheric monofocal regular LASIK in the dominant eye to correct myopia and presbyopia between January 2017 and August 2020. Monocular and binocular uncorrected distance visual acuity (UDVA) and near visual acuity (UNVA), and corrected distance visual acuity and near visual acuity were analyzed postoperatively. RESULTS: At 6 months postoperatively, the mean UDVAs (logMAR) in the dominant and nondominant eyes were 0.01 ± 0.02 and 0.26 ± 0.15, respectively. Furthermore, all treated dominant eyes achieved 20/20 or better monocular UDVA, and 84% achieved 20/16 or better monocular UDVA. In the nondominant treated eyes, 89% achieved 20/50 or better monocular UDVA, 78% achieved 20/40 or better, and 34% achieved 20/32 or better. The binocular cumulative UDVA at 6 months postoperatively was 20/20 or better in all patients. All patients achieved J2 or better in binocular cumulative UNVA, and 83% achieved J1. CONCLUSIONS: Presbyopia correction using the combination of PresbyMAX in the near eye and aspheric monofocal regular LASIK in the distant eye is a safe and effective treatment for presbyopia in patients with myopia.
Subject(s)
Keratomileusis, Laser In Situ , Myopia , Presbyopia , Humans , Presbyopia/surgery , Retrospective Studies , Vision, Binocular , Corneal Topography , Cornea/surgery , Myopia/surgery , Treatment Outcome , Lasers, Excimer , Refraction, OcularABSTRACT
(1) Introduction: We analysed epithelial changes after the treatment of moderate myopia with transepithelial photorefractive keratectomy. (2) Materials and Methods: We used optical coherence tomography data and analysed changes in the stroma and epithelium after ablation. We aimed to ascertain how much epithelium hyperplasia occurred after TransPRK; for this, we used data from 50 eyes treated with TransPRK with the AMARIS 1050 Hz, with a minimum follow-up of 4 months. (3) Results: The measured epithelial changes corresponded to a less than 0.1 ± 0.2D of spherical effect, less than 0.2 ± 0.2D of astigmatic effect, and less than 0.5 ± 0.2D of comatic effect. (4) Conclusions: The changes in epithelial thickness after aberration-neutral transepithelial photorefractive keratectomy for moderate myopia were very small, indicating a low level of epithelial hyperplasia without resembling a regression-inducing lentoid.
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PURPOSE: This article proposes a simple model that describes the quantitative relationship between visual acuity and defocus (as in defocus curves) in the presence of higher-order aberrations (HOA). METHODS: The basis model for describing the relationship between visual acuity and blur was taken from Blendowske as a starting point to develop an extended model applicable to defocus curves. The basis of Blendowskes's data is extended by incorporating effects induced by HOA. Aberrometric refractive errors are transformed into a single blur quantity b, also termed dioptric distance, which serves as an input in both models. The possible influence of the axes of asymmetric aberrations and the pupil size is not included. RESULTS: The extended model has been used to generate reference data for a bi-aspheric multifocal correction profile for presbyopia. It provides reference data similar to what has been reported in the literature for that particular profile. CONCLUSIONS: The model proposed in this article can be used to determine depth-of-focus effects associated with the presence of HOA. The extended model seems to provide a valid description for defocus curves. Actual uncertainties in experimental data on unaided visual acuity, especially the frequent lack of information on pupil diameter, prevent meaningful numerical comparison and the refinement of both models. However, theoretical arguments are provided in support of the extended model.
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PURPOSE: To determine corneal cross-linking (CXL) efficacy and chromophore penetration after excimer laser-assisted patterned de-epithelialization. METHODS: Two-hundred-twenty porcine eyes were de-epithelialized ex vivo, either fully (mechanical; n = 88) or patterned (excimer laser; n = 132). Consecutively, corneas were impregnated with hypo- or hyperosmolar riboflavin (RF; n = 20, RF-D; n = 40, respectively) or water-soluble taurine (WST11; n = 40, and WST-D; n = 40, respectively), or kept unimpregnated (n = 80). Sixty corneas were subsequently irradiated, inducing CXL, with paired contralateral eyes serving as controls. Outcome measurements included strip extensiometry to assess CXL efficacy, and spectrophotometry and fluorescence microscopy to determine stromal chromophore penetration. RESULTS: All tested chromophores induced significant CXL (p < 0.001), ranging from 7.6% to 14.6%, with similar stiffening for all formulations (p = 0.60) and both de-epithelialization methods (p = 0.56). Light transmittance was significantly lower (p < 0.001) after full compared with patterned de-epithelialization. Stromal chromophore penetration was comparable between fully and patterned de-epithelialized samples, with full penetration in RD and RF-D samples and penetration depths measuring 591.7 ± 42.8 µm and 592.9 ± 63.5 µm for WST11 (p = 0.963) and 504.2 ± 43.2 µm and 488.8 ± 93.1 µm for WST-D (p = 0.669), respectively. CONCLUSIONS: Excimer laser-assisted patterned de-epithelialization allows for effective CXL. Stromal chromophore concentration is, however, reduced, which may have safety implications given the need for sufficient UVA attenuation in RF/UVA CXL. The different safety profile of near-infrared (NIR) may allow safe WST11/NIR CXL even with reduced stromal chromophore concentration values. In vivo studies are needed to evaluate the benefits and further assess safety of excimer laser-assisted patterned de-epithelialization for corneal CXL.
Subject(s)
Corneal Stroma , Lasers, Excimer , Animals , Collagen/pharmacology , Cornea/surgery , Corneal Stroma/surgery , Cross-Linking Reagents/pharmacology , Humans , Lasers, Excimer/therapeutic use , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Riboflavin/pharmacology , Riboflavin/therapeutic use , Swine , Ultraviolet RaysABSTRACT
A theoretical method to determine the optimum laser parameters for maximizing the cutting efficiency for different materials (in particular human cornea) is proposed. The model is simple and reduced to laser beam characteristics and cavitation properties. The model further provides a method to convert energy fluctuations during the cutting process to equivalent deviations in the cavitation bubbles. The proposed model can be used for calibration, verification and validation purposes of laser systems used for cutting processes at relatively low cost and may improve the quality of the results.
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PURPOSE: To evaluate refractive and visual outcomes of small incision guided human cornea treatment (SmartSight; SCHWIND eye-tech-solutions) in the treatment of myopic astigmatism with the use of a new femtosecond laser system. METHODS: This retrospective, observational case series study included 104 eyes of 56 patients who underwent SmartSight to correct myopic astigmatism and completed the 3-month follow-up. Procedures were performed with a SCHWIND ATOS femtosecond laser. RESULTS: Preoperatively, mean manifest spherical equivalent refraction was -6.12 ± 1.99 diopters (D) (range: -3.00 to -11.50 D) and astigmatism was 1.02 ± 0.56 D (range: 0.25 to 2.75 D). Three months postoperatively, it was +0.47 ± 0.32 D (range: -0.75 to +1.00 D) and 0.27± 0.22 D (range: 0.00 to 0.75 D), respectively (both P < .05). Spherical equivalent correction within ±0.50 D was achieved in 62 eyes (60%), and cylindrical correction in 90 eyes (87%). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 94 eyes (90%) and postoperative uncorrected distance visual acuity was 20/20 or better in 96 eyes (92%). No eye lost two or more Snellen lines of CDVA. CONCLUSIONS: Myopic astigmatism correction with Smart-Sight provided good results for efficacy, safety, predictability, and visual outcomes in the first 3 months of follow-up. [J Refract Surg. 2021;37(5):304-311.].
Subject(s)
Astigmatism , Astigmatism/surgery , Cornea/surgery , Follow-Up Studies , Humans , Lasers, Excimer/therapeutic use , Prospective Studies , Refraction, Ocular , Retrospective Studies , Treatment OutcomeABSTRACT
PURPOSE: To evaluate the long-term efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) for postkeratoplasty refractive error correction. METHODS: A retrospective interventional case series of 54 eyes of 50 patients who underwent previous corneal transplants. Unaided distance visual acuity (UDVA) and best corrected visual acuity (CDVA), manifest refraction, mean central keratometric value, mean keratometric astigmatism, and postoperative complications were reviewed. RESULTS: Final follow-up was at mean 31 (±17) months. Sixteen point seven percent of eyes underwent more than 1 surface ablation. Mean UDVA improved from 0.96 ± 0.06 logarithm of the minimum angle of resolution (LogMAR) preoperatively to 0.46 ± 0.05 LogMAR of resolution at the final follow-up (Bonferroni, P < 0.0001). Mean UDVA improved by 4.4 Snellen lines. Improvement in CDVA was not significant, although a significant improvement was noted when eyes with preoperative CDVA <20/40 were analyzed separately (t test, P = 0.005). Mean astigmatism improved from -4.4 ± 0.26 D preoperatively to -2.4 ± 0.26 D at the final follow-up (Bonferroni, P < 0.0001), whereas mean SEQ improved from -2.5 ± 0.39 D preoperatively to -1.1 ± 0.25 D (Bonferroni, P = 0.02). In total, 9% at the preoperative visit and 55% at the final visit had less than 2 D of astigmatism, respectively. Keratometric astigmatism decreased from 5.24 ± 0.36 D preoperatively to 2.98 ± 0.34 D at the final follow-up (t test, P < 0.0001). No eyes developed clinically significant haze, 14.8% developed regression, and 13% had a reduction of 2 or more CDVA lines. CONCLUSIONS: Postkeratoplasty topography-guided photorefractive keratectomy has good long-term efficacy and safety, resulting in significant UDVA, refractive, and keratometric improvement. Regression can occur after the first year of treatment, emphasizing the importance of long-term follow-up.
Subject(s)
Astigmatism/surgery , Keratoplasty, Penetrating/adverse effects , Lasers, Excimer/therapeutic use , Photorefractive Keratectomy/methods , Postoperative Complications , Adult , Aged , Astigmatism/etiology , Astigmatism/physiopathology , Corneal Topography , Female , Follow-Up Studies , Humans , Male , Middle Aged , Refraction, Ocular/physiology , Retrospective Studies , Surgery, Computer-Assisted , Treatment Outcome , Visual Acuity/physiology , Young AdultABSTRACT
In this case report, we propose to correct refractive errors after SMILE a refractive lenticule surgery technique with transepithelial Photorefractive keratectomy (TransPRK).The advantage of this technique is that the measured aberrations with topography o the Cornea are also treated on the Surface of the Cornea.
Subject(s)
Astigmatism , Myopia , Photorefractive Keratectomy , Refractive Errors , Astigmatism/surgery , Cornea/surgery , Corneal Topography , Humans , Myopia/surgery , Refraction, Ocular , Visual AcuityABSTRACT
PURPOSE: To evaluate refractive and visual outcomes of single-step transepithelial photorefractive keratectomy (transPRK) in the treatment of mixed astigmatism with the use of an aberration-neutral profile and large ablation zone. SETTING: Nicolaus Copernicus University and Oftalmika Eye Hospital, Bydgoszcz, Poland. DESIGN: Retrospective, observational case series. METHODS: This study included patients who underwent transPRK to correct mixed astigmatism and completed the 3-year follow-up. Procedures were performed with an Amaris 750S excimer laser using an aberration-neutral profile and optical zone of 7.2 mm or more. RESULTS: A total 48 eyes of 39 patients were included. Preoperatively, mean spherical manifest refraction was +1.37 ± 0.98 diopter (D) (0.25 to 4.00 D), and astigmatism was -4.00 ± 0.76 D (-2.25 to -6.00 D). Three years postsurgery, it was -0.17 ± 0.26 D and -0.41 ± 0.44 D, respectively. Attempted spherical equivalent correction within ±0.50 D was achieved in 45 eyes (94%) and cylindrical correction in 34 (71%). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 38 eyes (79%), and postoperative uncorrected was 20/20 or better in 29 eyes (60.0%). No eye had lost 2 or more Snellen lines of CDVA, whereas 3 eyes (6%) gained 2 or more lines. In 4 eyes (8%), haze of low intensity was observed at the periphery, with scores between 0.5 and 1.0, and only 1 eye getting a score of 2 in 0- to 4-degree scale. CONCLUSIONS: Mixed astigmatism correction with large-ablation-zone transPRK provided good results for efficacy, safety, predictability, and visual outcomes in a 3-year follow-up.
Subject(s)
Astigmatism , Photorefractive Keratectomy , Astigmatism/surgery , Cornea , Follow-Up Studies , Humans , Lasers, Excimer/therapeutic use , Refraction, Ocular , Retrospective Studies , Treatment OutcomeABSTRACT
PURPOSE: To evaluate the influence of a thin cap in small-incision lenticule extraction (SMILE) for the correction of myopia or myopic astigmatism. SETTING: Tertiary care private practice. METHODS: A chart review of 102 eyes of 51 patients was performed. The effect of 120 µm vs 100 µm cap thickness on postoperative spherical equivalent refraction (SEQ), cylinder, corrected and uncorrected visual acuities, and ease of lenticule separation was assessed in a contralateral manner, whereas all other parameters were identical between eyes (including optical zone, minimum lenticule thickness, incision size, and energy and spot settings) using paired t test. RESULTS: At 3 months postoperatively, SMILE with 120 µm cap thickness was undercorrected in SEQ relative to SMILE with 100 µm cap thickness in a cohort of 102 eyes of 51 consecutive patients. The difference of 0.06 ± 0.39 diopter (or 0.7% ± 5.7%) did not reach statistical significance. Postoperative cylinder was not statistically different in both groups. Visual acuity was similar in both groups. Ease of lenticule separation was identical in both groups. Suction time was shorter with a 100 µm cap (P < .005). Postoperative central residual stromal thickness was 20 ± 15 µm thicker with a 100 µm cap (P < .0001). Adverse events were comparable. CONCLUSIONS: Postoperative refraction, visual acuity, ease of lenticule separation, and incidence of adverse events were not significantly affected by cap thickness. Surgeons might safely use 100 µm instead of 120 µm caps without nomogram adjustment. Alternatively, after suction loss during the lenticule cut, a second docking with a programmed cap thickness of 100 µm (and a larger optical zone) might be a rescue technique enabling surgeons to still perform the intended SMILE procedure.