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Acta Ophthalmologica Dec 2021To comprehensively compare visual quality between small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK). (Comparative Study)
Comparative Study
PURPOSE
To comprehensively compare visual quality between small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK).
METHODS
Sixty-four eyes in the SMILE group and 42 eyes in the tPRK group were enrolled in this study. In both groups, visual acuity, manifest refraction, higher-order aberrations (HOAs), contrast sensitivity (CS) at four spatial frequencies (3, 6, 12, 18 c/d) under three conditions (photopic, low glare, high glare), the cut-off value of the modulation transfer function (MTFcut-off), the objective scatter index (OSI) and the Strehl ratio (SR) were measured preoperatively and 1, 3 and 6 months postoperatively.
RESULTS
At 6 months postoperatively, the SMILE and tPRK groups showed similar safety, efficacy and predictability. Additionally, MTFcut-off, SR and OSI exhibited comparable results. In contrast, the photopic area under the logarithm of the CS function (AULCSF) showed better outcomes in the tPRK group than in the SMILE group (SMILE versus tPRK: 1.21 ± 0.10 versus 1.25 ± 0.09, p = 0.014). Furthermore, the induced coma aberrations were larger in the SMILE group (SMILE versus tPRK: 0.10 ± 0.16 versus 0.06 ± 0.12, 95% CI [0.08, 0.31], p < 0.0001).
CONCLUSIONS
Both SMILE and tPRK obtained comparable visual quality at 6 months postoperatively, accompanied by better photopic CS and smaller induced coma aberrations with tPRK. Paying more attention to alignment or developing a centration technique would be beneficial for visual quality when performing SMILE.
Topics: Adolescent; Adult; Contrast Sensitivity; Corneal Stroma; Corneal Topography; Epithelium, Corneal; Female; Follow-Up Studies; Humans; Lasers, Excimer; Male; Myopia; Photorefractive Keratectomy; Postoperative Period; Retrospective Studies; Time Factors; Visual Acuity; Young Adult
PubMed: 33982437
DOI: 10.1111/aos.14823 -
Journal of Refractive Surgery... Aug 2016To compare the refractive outcomes of small incision lenticule extraction (SMILE) with photorefractive keratectomy (PRK) using an aberration-free ablation profile. (Comparative Study)
Comparative Study Randomized Controlled Trial
PURPOSE
To compare the refractive outcomes of small incision lenticule extraction (SMILE) with photorefractive keratectomy (PRK) using an aberration-free ablation profile.
METHODS
One eye of patients diagnosed as having myopia for bilateral refractive correction was randomly allocated to either PRK or SMILE. The primary outcome measures included refractive efficacy, predictability, safety, stability, corneal aberrations, and adverse events. Patients were followed up for 1 year postoperatively; postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and corneal aberrations were recorded and compared with preoperative data.
RESULTS
Thirty-nine patients in the PRK group and 35 patients in the SMILE group completed the study. The mean preoperative spherical equivalent refractions were -3.27 ± 0.62 diopters (D) for the PRK group and -3.56 ± 1.12 D for the SMILE group. The average postoperative spherical equivalent refractions were -0.26 ± 0.29 and -0.43 ± 0.38 D for the PRK and SMILE groups, respectively (P = .06). Total higher order aberrations in the 6-mm central corneal zone were significantly higher in the SMILE group (0.21 ± 0.10 µm) than in the PRK group (0.09 ± 0.03 µm) (P = .01) 12 months postoperatively. However, no statistically significant differences were found among spherical, trefoil, and coma aberrations between the groups.
CONCLUSIONS
The refractive results of PRK with aberration-free aspheric ablation are similar to those of SMILE in eyes with low myopia. The induction of coma, spherical, and trefoil aberrations did not statistically differ after both surgeries, but the total higher order aberrations after SMILE were significantly higher than PRK with aberration-free aspheric ablation. [J Refract Surg. 2016;32(9):604-610.].
Topics: Adult; Corneal Stroma; Corneal Surgery, Laser; Female; Follow-Up Studies; Humans; Lasers, Excimer; Male; Microsurgery; Middle Aged; Myopia; Photorefractive Keratectomy; Refraction, Ocular; Treatment Outcome; Visual Acuity; Young Adult
PubMed: 27598730
DOI: 10.3928/1081597X-20160602-02 -
BMC Ophthalmology Jun 2018To compare the clinical outcomes of wavefront-optimized (WFO) transepithelial photorefractive keratectomy (trans-PRK) and corneal wavefront-guided (CWFG) trans-PRK for... (Comparative Study)
Comparative Study Observational Study
BACKGROUND
To compare the clinical outcomes of wavefront-optimized (WFO) transepithelial photorefractive keratectomy (trans-PRK) and corneal wavefront-guided (CWFG) trans-PRK for myopic eyes with moderate to high astigmatism.
METHODS
One hundred ninety-six eyes (196 patients) with moderate to high astigmatism (≥ 1.75 D) treated with WFO or CWFG trans-PRK (101 and 95 eyes, respectively) were retrospectively registered. Safety, efficacy, predictability, vector analysis, and corneal aberrations were compared between groups preoperatively and at 6 months postoperatively.
RESULTS
At postoperative 6 months, the mean logMAR uncorrected distance visual acuity was similar in the WFO (- 0.07 ± 0.08) and CWFG (- 0.07 ± 0.07) groups. Safety, efficacy, and predictability of refractive and visual outcomes were also similar. The correction indices were 1.02 ± 0.14 and 1.03 ± 0.13 in the WFO and CWFG groups, respectively, with no significant difference. The absolute values of the angle of error were significantly higher in the WFO group (2.28 ± 2.44 vs. 1.40 ± 1.40; P = 0.002). Corneal total root mean square higher-order aberrations and corneal spherical aberrations increased postoperatively in both groups; however, the change was smaller in the CWFG group. Corneal coma showed a significant increase postoperatively only in the WFO group.
CONCLUSIONS
WFO and CWFG trans-PRK are safe and effective for correcting moderate to high astigmatism. However, CWFG trans-PRK provides a more predictable astigmatism correction axis and fewer induced corneal aberrations.
Topics: Adolescent; Adult; Astigmatism; Corneal Topography; Corneal Wavefront Aberration; Epithelium, Corneal; Female; Follow-Up Studies; Humans; Lasers, Excimer; Male; Myopia; Photorefractive Keratectomy; Postoperative Period; Refraction, Ocular; Retrospective Studies; Treatment Outcome; Visual Acuity; Young Adult
PubMed: 29940974
DOI: 10.1186/s12886-018-0827-x -
Arquivos Brasileiros de Oftalmologia Apr 2016To evaluate ocular straylight before and after photorefractive keratectomy (PRK) for low myopia with and without topical mitomycin (MMC) treatment. (Clinical Trial)
Clinical Trial
PURPOSE
To evaluate ocular straylight before and after photorefractive keratectomy (PRK) for low myopia with and without topical mitomycin (MMC) treatment.
METHODS
Patients who underwent PRK for low myopia were enrolled into the study. PRK without MMC was performed in 21 eyes (12 patients), whereas PRK with topical 0.02% MMC was performed in 25 eyes (14 patients). Both groups were treated using the NIDEK EC5000 excimer laser. Measurements were performed using the C-Quant straylight meter preoperatively and at two and four months postoperatively.
RESULTS
The mean patient age was 30 ± 4 years, and the mean spherical equivalent refractive error was -2.2 ± 0.75 D. The mean preoperative intraocular straylight values were 1.07 ± 0.10 in the PRK without MMC group and 1.07 ± 0.11 log(s) in the PRK with topical MMC group. At two months after surgery, there was a decrease in mean intraocular straylight values in both groups. However, a significant difference was only reached in the PRK with MMC group [0.98 ± 0.09 log(s), p=0.002] compared with preoperative values, which was likely due to a greater scatter of measurements in the PRK without MMC group [1.03 ± 0.13 log(s), p=0.082]. At four months postoperatively, ocular straylight values were not significantly different compared with those at baseline in either the PRK without MMC group [1.02 ± 0.14 log(s), p=0.26] or in the PRK with topical MMC group [1.02 ± 0.11 log(s), p=0.13].
CONCLUSION
PRK for low myopia decreases ocular straylight, and MMC application further reduces straylight in the early postoperative period. However, ocular straylight values do not significantly differ at four months after surgery compared with those at baseline.
Topics: Administration, Ophthalmic; Adult; Corneal Diseases; Corneal Wavefront Aberration; Cross-Linking Reagents; Female; Humans; Lasers, Excimer; Light; Male; Middle Aged; Mitomycin; Myopia; Photorefractive Keratectomy; Postoperative Period; Scattering, Radiation
PubMed: 27224070
DOI: 10.5935/0004-2749.20160027 -
Cornea Jun 2023The aim of this study was to present the 3-year outcomes after simultaneous transepithelial phototherapeutic keratectomy (t-PTK) and conventional photorefractive...
Three-Year Results of Simultaneous Transepithelial Phototherapeutic Keratectomy and Conventional Photorefractive Keratectomy (Cretan Protocol Plus) Followed by Corneal Crosslinking for Keratoconus.
PURPOSE
The aim of this study was to present the 3-year outcomes after simultaneous transepithelial phototherapeutic keratectomy (t-PTK) and conventional photorefractive keratectomy (PRK) followed by corneal crosslinking (CXL) for keratoconus.
METHODS
In this prospective, interventional case series, patients with progressive keratoconus underwent simultaneous t-PTK and conventional PRK followed by CXL (Cretan protocol plus). Visual, refractive, and topographic outcomes were evaluated along with endothelial cell density (ECD) preoperatively and at 1, 2, and 3 years postoperatively.
RESULTS
Twenty-two patients (31 eyes) were enrolled. No intraoperative or postoperative complications were observed in any of the patients. Logarithm of the minimum angle of resolution (logMAR) mean uncorrected and mean corrected distance visual acuity improved from 0.81 ± 0.40 and 0.18 ± 0.21 preoperatively to 0.38 ± 0.33 ( P < 0.001) and 0.06 ± 0.12 ( P < 0.001) at 3-year follow-up. Mean spherical equivalent improved from -5.39 ± 3.89 diopters (D) preoperatively to -2.29 ± 2.65 D ( P < 0.001) at 3 years postoperatively. Mean corneal astigmatism reduced from -4.70 ± 2.86 D preoperatively to -3.55 ± 2.45 D ( P = 0.001) at 3 years postoperatively. No ECD alterations were observed throughout the 3-year follow-up ( P > 0.05).
CONCLUSIONS
Simultaneous t-PTK and conventional PRK followed by CXL seems to be an effective and safe treatment for progressive keratoconus over 3-year follow-up.
Topics: Humans; Photorefractive Keratectomy; Keratoconus; Photosensitizing Agents; Lasers, Excimer; Prospective Studies; Riboflavin; Combined Modality Therapy; Corneal Topography; Follow-Up Studies; Corneal Stroma; Cross-Linking Reagents
PubMed: 36730364
DOI: 10.1097/ICO.0000000000003168 -
Cornea Mar 2018To evaluate the visual acuity and keratometric and aberrometric changes in patients with corneal transplants (PKP), who underwent topography-guided photorefractive...
PURPOSE
To evaluate the visual acuity and keratometric and aberrometric changes in patients with corneal transplants (PKP), who underwent topography-guided photorefractive keratectomy (TG-PRK) with mitomycin C (MMC).
METHODS
In this case study, 15 patients with spherical equivalents ranging from -11.00 to -0.25 diopters (D) who underwent penetrating corneal transplantation and had irregular astigmatism ranging from -7.5 to -2.0 D underwent TG-PRK with MMC. Corneal topography and wavefront of all patients were measured preoperatively and 12 months postoperatively.
RESULTS
Twelve months after TG-PRK with MMC, 46% of eyes achieved a best spectacle-corrected visual acuity (BSCVA) of 20/20 compared with 1 eye preoperatively (P = 0.0221, χ test). The BSCVA did not improve in 1 patient and increased by 1 line or more in all others. Astigmatism decreased significantly (P = 0.003) from 5.10 ± 0.4 D to 3.37 ± 0.06 D, the corneal best-fit sphere increased and keratometry measurements flattened significantly (P = 0.0001 for both comparisons), and the corneal total root mean square aberrations and trefoil decreased significantly (P = 0.0077 and P = 0.0054, respectively) from 9.11 ± 2.56 μm to 7.58 ± 3.15 μm and 2.00 ± 1.2 to 1.38 ± 0.27 μm, respectively, as measured by wavefront aberrometry.
CONCLUSIONS
Twelve months postoperatively, the BSCVA improved significantly, the lines of vision increased, and astigmatism, corneal best-fit sphere, mean keratometry, corneal thickness, corneal root mean square total, and corneal spherical aberrations decreased. TG-PRK with MMC is a good alternative for correcting post-PKP cases with irregular astigmatism with elevated higher-order aberrations.
Topics: Adolescent; Adult; Aged; Astigmatism; Corneal Topography; Corneal Wavefront Aberration; Female; Humans; Keratoplasty, Penetrating; Male; Middle Aged; Mitomycin; Photorefractive Keratectomy; Postoperative Complications; Visual Acuity; Young Adult
PubMed: 29215394
DOI: 10.1097/ICO.0000000000001474 -
BMC Ophthalmology Aug 2018To evaluate the safety, efficacy, and the refractive outcomes of single-step transepithelial photorefractive keratectomy (TransPRK) for the correction of mild, moderate,...
BACKGROUND
To evaluate the safety, efficacy, and the refractive outcomes of single-step transepithelial photorefractive keratectomy (TransPRK) for the correction of mild, moderate, and high myopia.
METHODS
This study consecutively recruited 32 high myopic eyes, 32 mild myopic and 32 moderate myopic eyes. Eyes with myopia that had undergone TransPRK treatment. Pre- and post-operative visual and refractive data, corneal Higher Order Aberration (HOA) as well as safety and efficacy indices were analyzed at 6 months postoperatively.
RESULTS
Six months after TransPRK, the manifest refraction spherical equivalent (SE) was not significantly between high myopia group and moderate myopia group (p = 0.636). No eyes lost ≥2 lines of corrected distant visual acuity (CDVA) in high myopic eyes. The uncorrected distance visual acuity (UDVA) was significantly higher in low and moderate myopia groups than the high myopia group (P < 0.001; P = 0.002). The CDVA was not significantly different between moderate and high myopia groups (P = 0.057). There was no significant difference in mean safety index between high myopia group (1.01 ± 0.14) and mild myopia group (1.08 ± 0.15) (P > 0.05). The mean safety index was significantly higher in the moderate myopia group (1.16 ± 0.23) than in the high myopia group (1.01 ± 0.14) (P = 0.002). The efficacy index was significantly higher in the moderate myopia group (1.05 ± 0.20) than in the high myopia group (0.89 ± 0.17) (P = 0.02), and there was no significant difference between the high myopia group (0.89 ± 0.17) and the low myopia group (0.96 ± 0.16) (P = 0.14).
CONCLUSIONS
The mean safety index was over 1.0 in the three groups. TransPRK showed acceptable safety and efficacy in the moderate myopic eyes, as well as mild and high myopic eyes. High myopic eyes got very similar refractive results with moderate myopic eyes six months postoperatively. The safety and efficacy indexes were not significantly different between the high myopia group and the low myopia group.
Topics: Adult; Analysis of Variance; Female; Humans; Lasers, Excimer; Male; Myopia; Myopia, Degenerative; Photorefractive Keratectomy; Prospective Studies; Refraction, Ocular; Visual Acuity; Young Adult
PubMed: 30153819
DOI: 10.1186/s12886-018-0888-x -
Journal Francais D'ophtalmologie Jun 2021To study corneal haze following myopic photorefractive keratectomy (PRK) in a high-risk population and to assess methods for minimizing the risk.
OBJECTIVES
To study corneal haze following myopic photorefractive keratectomy (PRK) in a high-risk population and to assess methods for minimizing the risk.
METHODS
The medical records of 150 patients who underwent PRK were reviewed. A total of 300 eyes were included. All patients underwent myopic PRK using the Allegretto Wave Concerto 500Hz (Wavelight AG, Erlangen, Germany)excimer laser platform with intraoperative mitomycin-C (MMC) application. Demographic data including age, gender and ethnicity in addition to preoperative and postoperative subjective manifest refraction, spherical equivalent, best-corrected distance visual acuity, uncorrected distance visual acuity (UDVA), postoperative corneal haze grade and other possible postoperative complications were retrieved. Hanna grading (0-4+) was used to evaluate corneal haze.
RESULTS
The patients were comprised of 74 men (49.3%) and 76 women (50.7%). The mean age at the time of surgery was 26.5±6.0 (range, 17-46) years. All patients were Saudis with brown irides. UDVA improved to 20/25 in 93.8% at 3 months. The mean and standard deviation of preoperative spherical equivalent was -3.02±1.63 (range, -7.63 - -0.13). At 3 months, postoperative spherical equivalent improved to 0.05±0.50 (-1.00 - +1.00). At 6 months, 13.6% exhibited corneal haze of grade 1, and none exhibited grades 2 or 3.
CONCLUSIONS
The results of this study confirmed that patients with brown irides can achieve favorable outcomes after PRK. MMC, postoperative topical steroids and ultraviolet protection evidently play a major role in preventing corneal haze in high-risk populations.
Topics: Cornea; Eye Color; Female; Germany; Humans; Lasers, Excimer; Male; Myopia; Photorefractive Keratectomy; Refraction, Ocular; Treatment Outcome
PubMed: 33858699
DOI: 10.1016/j.jfo.2020.11.011 -
Cornea Jan 2021To evaluate the long-term efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) for postkeratoplasty refractive error correction.
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.
Topics: Adult; Aged; Astigmatism; Corneal Topography; Female; Follow-Up Studies; Humans; Keratoplasty, Penetrating; Lasers, Excimer; Male; Middle Aged; Photorefractive Keratectomy; Postoperative Complications; Refraction, Ocular; Retrospective Studies; Surgery, Computer-Assisted; Treatment Outcome; Visual Acuity; Young Adult
PubMed: 32956581
DOI: 10.1097/ICO.0000000000002403 -
Journal of Cataract and Refractive... Dec 2023To compare astigmatic correction among cross-assisted small-incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and...
PURPOSE
To compare astigmatic correction among cross-assisted small-incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and transepithelial photorefractive keratectomy (transPRK).
SETTING
The Eye Hospital of Wenzhou Medical University, Zhejiang, China.
DESIGN
Prospective comparison study.
METHODS
154 right eyes of 154 patients with astigmatism of -1.00 to -2.75 diopters (D) were included in this study. 64 eyes, 42 eyes, and 48 eyes were receiving SMILE, FS-LASIK, and transPRK, respectively. The SMILE group used cross-axial alignment for head positioning for astigmatism correction. In the FS-LASIK and transPRK groups, static and dynamic cyclotorsion control were used. Changes in ocular parameters and vector analysis were assessed at 6 months postoperatively.
RESULTS
The safety and efficacy indices were comparable among the 3 groups at 6 months postoperatively. Residual astigmatism was smallest in the SMILE group (-0.23 ± 0.25 D) compared with that in FS-LASIK (-0.40 ± 0.28 D, P = .009) and transPRK groups (-0.42 ± 0.32 D, P = .001). 53 (82.8%), 36 (85.7%), and 37 (77.1%) eyes achieved an angle of error within ±5 degrees, respectively ( P = .55). Notably, vector analysis showed that the difference vector, the magnitude of the error, and its absolute value were significantly smaller in the SMILE group than those in the other groups ( P < .05). In addition, the higher-order aberrations, especially coma, were significantly induced postoperatively in each group ( P < .001).
CONCLUSIONS
Residual astigmatism magnitude was smallest by cross-assisted SMILE, followed by FS-LASIK and transPRK, and the astigmatism axial correction was comparable among groups.
Topics: Humans; Photorefractive Keratectomy; Keratomileusis, Laser In Situ; Astigmatism; Myopia; Eye; Surgical Wound
PubMed: 37616187
DOI: 10.1097/j.jcrs.0000000000001294