Journal of refractive surgery最新文献

Purpose: To compare clinical outcomes of transepithelial photorefractive keratectomy (t-PRK) and conventional epithelium-off PRK (PRK) in patients with high compound myopic astigmatism.

Methods: Sixty eyes of 30 myopic individuals with at least -2.50 diopters (D) of spherical equivalent and 3.00 D of cylindrical refractive error were enrolled in the study. Both eyes of each patient were randomly assigned to either the t-PRK method or epithelium-off PRK as a matched contralateral control group. Refractive outcomes were evaluated 6 months after surgery.

Results: At the 6-month visit, cylindrical refractive error magnitude was lower in the t-PRK (0.51 ± 0.29 D) compared to the PRK (0.67 ± 0.30 D) group (P = .04). The residual astigmatism was 0.50 diopters or less in 23 eyes (76%) in the t-PRK group and 15 eyes (50%) in the PRK group. In vector analysis using the Alpins method, t-PRK resulted in a significantly higher percentage of success of astigmatic surgery (84.68 ± 8.95 in t-PRK versus 79.46 ± 10.88 in PRK, P = .04). Additionally, there was a marginal advantage for the t-PRK group regarding index of success of astigmatism surgery (P = .06) and absolute (P = .08) and arithmetic (P = .07) angles of error compared to the PRK group. Both groups had an equal safety profile.

Conclusions: T-PRK is more accurate for astigmatic correction in high astigmatism than conventional PRK. Both t-PRK and PRK are comparable respecting safety and efficacy. [J Refract Surg. 2024;40(12):e956-e965.].

Purpose: To evaluate the refractive prediction error of common intraocular lens (IOL) power calculation formulas in patients who underwent intrascleral IOL fixation using the four-flanged technique.

Methods: This prospective, longitudinal, single-site, single-surgeon study's setting was the Department for Ophthalmology and Optometry, Medical University of Vienna, Austria. Patients who received IOL implantation via the four-flanged technique were followed up to 3 months after the operation. Refraction was measured using the Early Treatment of Diabetic Retinopathy Study visual acuity test at 4 m. Lens decentration, tilt, and aqueous anterior chamber depth were evaluated using anterior segment optical coherence tomography. The SRKT, Holladay 1, and Hoffer-Q formulas were used to assess prediction error (PE) and absolute error (AE). Correlations between axial length, keratometry, and white-to-white distance were subsequently evaluated.

Results: A total of 28 eyes of 28 patients were examined in this study. The application of all formulas resulted in a hyperopic PE (SRKT: 0.35 ± 0.86 diopters [D], Holladay 1: 0.36 ± 0.78 D and Hoffer-Q: 0.37 ± 0.73 D). There was no variation between the PE of different formulas discovered (P > .05). The AE was within 0.50 D in 54% to 61% and within 1.00 D in 79% of eyes, depending on the formula used. Furthermore, Cochrane's Q test detected no significant distinctions between formulas (P > .05). The PE of each formula demonstrated a significant correlation to the axial length of the eyes (P < .05). The correlation estimates ranged from -0.25 D/mm to -0.39 D/mm, subject to the applied formula.

Conclusions: This study demonstrates that the four-flanged technique for scleral IOL fixation yields reliable outcomes. PE was closest to zero using the Hoffer-Q formula, although there was no statistically significant difference compared to the other formulas. Axial length emerged as the most pertinent factor for PE. Short eyes resulted in a more hyperopic outcome, whereas longer eyes resulted in a more myopic outcome than intended. This myopic and hyperopic shift was due to the standardized surgical technique with an externalization of the haptics 2.5 mm behind the limbus resulting in a consistent aqueous anterior chamber depth across all eye lengths, coupled with a reduction or increase in the distance from the IOL to the macula, which is dependent on the length of the eye. [J Refract Surg. 2024;40(12):e985-e993.].

Purpose: To evaluate the performance of the InnovEyes Sightmap platform (Alcon Laboratories, Inc) in refractive surgery by comparing the visual acuity and higher order aberrations (HOAs) between ray-tracing-guided laser in situ keratomileusis (LASIK) and topography-guided LASIK.

Methods: This prospective study enrolled participants who underwent either ray-tracing-guided LASIK or topography-guided LASIK. Comprehensive ophthalmic evaluations were performed preoperatively, as well as at 1 day, 2 weeks, 1 month, and 3 months postoperatively. Patients in the ray-tracing-guided LASIK group underwent wavefront, tomography, and biometry assessment using the InnovEyes Sightmap diagnostic device. Assessments included visual acuity, manifest refraction, and whole-eye HOAs.

Results: A total of 42 eyes treated with ray-tracing-guided LASIK and 42 eyes treated with topography-guided LASIK were analyzed. Both strategies demonstrated comparable good refraction accuracy and refractive stability (P > .05). The ray-tracing-guided LASIK group exhibited significantly better postoperative uncorrected distance visual acuity (UDVA) compared to the topography-guided LASIK group (-0.12 ± 0.05 vs -0.07 ± 0.04 logarithm of the minimum angle of resolution, respectively; P < .05), with 48% of eyes achieving a UDVA of 20/12.5 or better. Ray-tracing-guided LASIK induced a small but statistically significant increase in HOAs and vertical coma aberration, along with a significant reduction in spherical aberration (P < .05). In contrast, topography-guided LASIK resulted in a significant increase in vertical coma (P < .05) without significant changes in overall HOAs or spherical aberration (P > .05). At 3 months postoperatively, spherical aberration was significantly different between the two groups (-0.021 ± 0.031 vs 0.054 ± 0.122 µm, respectively; P < .05).

Conclusions: The InnovEyes Sightmap platform's ray-tracing-guided LASIK demonstrated potential advantages in visual acuity outcomes compared to topography-guided LASIK. The observed negative shift in spherical aberration, characterized by a lower absolute value, may have contributed to the enhanced visual acuity results. [J Refract Surg. 2024;40(12):e994-e1002.].

Purpose: To present a new approach to customized treatments that inherently saves tissue by design, especially for pathological corneas.

Methods: From the elevation of the anterior cornea and the refractive error of the eye, the target cornea can be calculated and the difference between actual and target cornea corresponds to the tissue to be removed. In this approach, it is further possible to preset the ablation depth at one (Model 1) or two (Models 2 and 3) particular locations. In all three models, the target cornea floats in z-direction, until the depth is reached at one of these defined locations. In Model 2, the depth at the second location is reached by modulating the asphericity, whereas in Model 3, asphericity is maintained but average curvature is modulated to achieve the desired depth at the second location. After floating in z-direction, and modulation, locations with a negative ablation value are set to zero (primary clipping). Additionally, locations exceeding a preset maximum ablation depth are set to a predefined depth (secondary clipping).

Results: Simulated cases based on patient diagnosis were used to better explain and illustrate the technique.

Conclusions: With this approach, free-form ablation zones are generated, providing for a tissue-saving correction of refractive error and partial correction of higher order aberrations, the overall corneal shape will be recentered, and the corneal curvature gradient is reduced. [J Refract Surg. 2024;40(12):e1003-e1014.].

Purpose: To compare the aberrometric profile of the Artisan Aphakia lens (Opthec BV) and transscleral plug FIL-SSF lens (Soleko) and to assess the impact of tilt and decentration on their optical performance.

Methods: This retrospective observational study was conducted at Azienda Ospedaliera Universitaria Careggi, Florence, Italy, with a consecutive cohort of aphakic eyes undergoing secondary lens implantation with an Artisan or FIL-SSF lens. Wavefront analysis was performed using a pyramidal wavefront-based aberrometer (Osiris-T; CSO). Tilt and decentration were calculated using anterior segment optical coherence tomography (MS-39; CSO).

Results: The study included 47 eyes from 45 patients: 24 eyes in the FIL-SSF group and 23 eyes in the Artisan group. Decentration was 0.39 ± 0.14 mm in the FIL-SSF group and 0.51 ± 0.16 mm in the Artisan group (P = .02). The mean tilt value was 6.6 ± 2.35 degrees in the FIL-SSF group and 5.9 ± 1.86 degrees in the Artisan group (P = .13). Internal higher order aberrations (HOAs) were 0.23 ± 0.07 μm in the FIL-SSF group and 0.29 ± 0.13 μm in the Artisan group (P = .02). The point spread function (PSF) Strehl ratio was 0.12 ± 0.05 in the FIL-SSF group and 0.10 ± 0.04 (P = .11) in the Artisan group. The PSF Strehl ratio without lower order aberration (PSFw2) was 0.28 ± 0.12 in the FIL-SSF group and 0.23 ± 0.09 in the Artisan group (P = .01).

Conclusions: The Artisan and FIL-SSF lenses provide comparable optical performance in terms of the PSF Strehl ratio. However, the Artisan lens appears to be more susceptible to decentration, which may result in increased higher order aberrations and a consequently lower PSFw2 Strehl ratio. [J Refract Surg. 2024;40(12):e926-e933.].

Purpose: To assess real-time intraoperative pachymetry changes occurring during corneal cross-linking (CXL) using microscope-integrated optical coherence tomography (Mi-OCT) and compare accuracy of various modalities of pachymetry assessment.

Methods: This was a cross-sectional observational comparative study including 45 consecutive patients with progressive keratoconus planned for CXL. Mi-OCT (RESCAN 700) was used to measure central corneal thickness (CCT) during four stages of CXL: before epithelial debridement, after debridement, after riboflavin instillation, and after ultraviolet irradiation. Scheimpflug imaging, anterior segment OCT (AS-OCT), and ultrasound pachymetry were used to assess CCT preoperatively. All data were entered into Excel software (Microsoft Corporation) and analyzed.

Results: The CCT significantly decreased after each step of CXL as measured on Mi-OCT (P < .0001). Mi-OCT overestimated the CCT significantly by 1.12 times on average (range: 1.02 to 1.43) compared to ultrasound pachymetry (P = .0004). CCT measured using Scheimpflug imaging and anterior segment OCT was statistically comparable to ultrasound pachymetry.

Conclusions: Mi-OCT provides a real-time assessment of CCT during CXL. However, because it overestimates the pachymetry, ultrasound pachymetry remains the gold standard for decision-making during CXL. [J Refract Surg. 2024;40(12):e934-e940.].

Purpose: 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).

Methods: 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.

Results: 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.

Conclusions: 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.].