- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Correlation between iris-registered static and dynamic cyclotorsions with?preoperative refractive astigmatism in PRK candidates
摘要： Purpose: To evaluate static and dynamic cyclotorsions during photorefractive keratotomy (PRK) surgery in refractive surgery candidates and their correlations with preoperative factors. Methods: This cross-sectional case series was performed in 138 eyes of 77 patients who underwent PRK surgery by Technolas 217z100. Iris registration was used to evaluate the degree of static and dynamic cyclotorsion. Wavefront measurements were performed in sitting position using Zywave (versions 3.1 and 3.2, Bausch & Lomb) Hartmann Shack aberrometer (Bausch & Lomb), and the cyclotorsion from upright to supine position was measured using iris image comparison. Dynamic cyclotorsions were measured by Advanced Cyclotorsional Eye Tracker (ACE) mounted on Excimer laser machine Technolas 217z100 during surgery. Results: The mean absolute static cyclotorsion that was captured in surgery time was 3.37 ± 2.38° (range, 0.00 to 11.30), and the mean absolute dynamic cyclotorsion was 2.54 ± 2.50° (range, 0.00 to 13.60). There was a significant correlation between dynamic cyclotorsions and static cyclotorsions (P < 0.001 and R = 0.704). There was a strong association between preoperative refractive astigmatism and range dynamic cyclotorsion. Total pulses (P = 0.009), ablation depth (P = 0.012), gender (P = 0.008), and laterality had significant correlations with cyclotorsional movements. Conclusion: The measurements of static and dynamic cyclotorsions are highly recommended for refractive surgery candidates with significant preoperative refractive astigmatism.
关键词： Astigmatism,Cyclotorsions,Refractive surgery
更新于2025-09-23 15:23:52
-
Estimation of Intraocular Lens Power Calculation after Myopic Corneal Refractive Surgery: Using Corneal Height in Anterior Segment Optical Coherence Tomography
摘要： Purpose: To investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery. Methods: This study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subsequent successful cataract surgery. The CH was measured with AS-OCT, and the measured ELP (ELPm) was calculated. Intraocular lens power, which could achieve actual emmetropia (Preal), was determined with medical records. Estimated ELP (ELPest) was back-calculated using Preal, axial length, and keratometric value through the SRK/T formula. After searching the best-fit regression formula between ELPm and ELPest, converted ELP and intraocular lens power (ELPconv, Pconv) were obtained and then compared to ELPest and Preal, respectively. The proportion of eyes within a defined error was investigated. Results: Mean CH, ELPest, and ELPm were 3.71 ± 0.23, 7.74 ± 1.09, 5.78 ± 0.26 mm, respectively. The ELPm and ELPest were linearly correlated (ELPest = 1.841 × ELPm – 2.018, p = 0.023, R = 0.410) and ELPconv and Pconv agreed well with ELPest and Preal, respectively. Eyes within ±0.5, ±1.0, ±1.5, and ±2.0 diopters of the calculated Pconv, were 23.3%, 66.6%, 83.3%, and 100.0%, respectively. Conclusions: Intraocular lens power calculation using CH measured with AS-OCT shows comparable accuracy to several conventional methods in eyes following corneal refractive surgery.
关键词： Intraocular lens power calculation,Corneal height,Corneal refractive surgery,Effective lens position,Anterior segment optical coherence tomography
更新于2025-09-23 15:22:29
-
Transepitheliale photorefraktive Keratektomie; Transepithelial photorefractive keratectomy;
摘要： Objective. To analyze and assess the refractive outcome after transepithelial photorefractive keratectomy (TransPRK). Material and methods. The treatment was performed with the AMARIS 1050RS laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). The method used an aspheric, aberration-neutral ablation profile and a standardized epithelial tissue removal of 55 μm in the center and 65 μm at a radius of 4 mm as well as SmartPulse technology. Only spherical and/or cylindrical refraction values were treated. Only untreated eyes with preoperative best corrected visual acuity equal to or better than 0.8 were included in the cohort. Follow-up examinations were performed after 1 and 4 days, after 1 and 3 months and after 1 year Results. A total of 939 consecutive TransPRK laser treatments performed in the period from December 2014 to December 2016 were retrospectively analyzed. The mean age of the patients was 34 years. The preoperative sphere had a range of –7.75 D up to +3.00 D and cylinders up to 5.00 D. The 3-month follow-up control was performed in 728 eyes (77.5%). The predictability showed 89% of eyes within the target correction of less than 0.50 D and 99% of eyes less than 1.00 D. The astigmatic correction showed 91% of eyes with less than 0.50 D. In the safety 1% of eyes showed a visual loss of 2 Snellen lines because of haze. In 26 eyes (2.7%) follow-up treatment was performed with renewed TransPRK laser treatment, in the myopic cohort in 1.8% and in the hyperopic cohort in 13.0%. A residual refraction occurred in 20 eyes without haze and 6 eyes showed a residual refraction with signs of haze. Conclusion. The TransPRK led to similar results to intrastromal refractive surgery techniques but with fewer clinical complications.
关键词： Myopia,SmartSurface,Astigmatism,Haze,Refractive surgery,Hyperopia
更新于2025-09-23 15:21:21
-
Excimer laser treatment combined with riboflavin ultraviolet-A (UVA) collagen crosslinking (CXL) in keratoconus: a literature review
摘要： Purpose To review the clinical outcome of keratoconus patients after excimer laser treatment with combined riboflavin UV-A collagen crosslinking (CXL) treatment was reviewed in light of the UDVA, CDVA and HOA. Methods Following a PubMed-based literature review of studies on excimer laser treatment with combined riboflavin UV-A CXL published between 2009 and 2018, peer-reviewed English-written studies were evaluated using the GRADE approach (www.gradeworkinggroup.org). The current review focused on the change in the (un)corrected distance visual acuity (UDVA; CDVA) and higher-order aberrations (HOA) as well as the prevalence of postoperative complications. Results Five studies with a total of 573 eyes were included, thereby reporting on 479 eyes were treated with the aforementioned combination therapy. The control group consisted of 94 eyes in total. Changes between pre- and postoperative CDVA and/or UDVA were statistically significant in all five studies after at least a 24-month follow-up period for the combined excimer laser-assisted CXL treatment in comparison with the CXL-only treatment option. Three studies described statistically significant reduction in the number of total HOA, in particular, those related to coma and spherical aberration. Corneal haze was reported in four studies, but the condition was successfully treated in all cases. Conclusion Current studies suggest that CDVA, UDVA and HOA in low-to-moderate keratoconic patients improved in a combined treatment without sacrificing biomechanical stability of the cornea. However, long-term results are needed, as the studies in our review have a follow-up period of 68 months or less.
关键词： Refractive surgery,Keratoconus,Collagen-crosslinking,Photorefractive keratectomy
更新于2025-09-23 15:21:01
-
Application of Femtosecond Laser in Anterior Segment Surgery
摘要： Femtosecond laser (FSL) is a near-infrared laser that can create reliable and reproducible tissue cutting with minimal damage to adjacent tissue. As the laser can also create incisions with various orientations, depths, and shapes, it is expected to be a useful tool for anterior segment surgery, such as cornea, refractive, and cataract surgery. In this review, the authors will introduce the application of FSL in various anterior segment surgeries and discuss the results of studies regarding the efficacy and safety of FSL in cornea, refractive, and cataract surgery. Experimental studies regarding the potential use of FSL will also be introduced. The studies discussed in this review suggest that FSL may be a useful tool for improving the prognosis and safety of surgeries of the anterior segment.
关键词： anterior segment surgery,Femtosecond laser,cataract surgery,refractive surgery,cornea surgery
更新于2025-09-23 15:19:57
-
Flap Sliding Technique for Managing Flap Striae following Laser In Situ Keratomileusis
摘要： Purpose. To assess the e?cacy and safety of a simple, noninvasive, “?ap-sliding” technique for managing ?ap striae following laser in situ keratomileusis (LASIK). Methods. This prospective, interventional study included eyes with post-LASIK ?ap striae. All eyes underwent ?ap sliding 1-2 days after surgery. Following ?ap edge epithelialisation, a cellulose sponge was used to gently slide the ?ap perpendicular to the striae direction. This technique allows for ?ap striae treatment without ?ap lifting, avoiding any associated lifting complications. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refractive error were monitored one day after the ?ap-sliding procedure. Results. Fifteen eyes (15 patients) with post-LASIK ?ap striae were managed using the ?ap-sliding technique. The procedure did not successfully relocate the ?ap striae in 1 eye, and ?ap elevation and ?oating (using a balanced salt solution) were required. Therefore, 14 eyes were included in post-?ap-sliding analyses. The UDVA improved in all patients the ?rst day after the ?ap-sliding procedure was performed, with 11 of 14 eyes (78.57%) reaching an UDVA of 20/25 or better. Complications following ?ap sliding occurred in 2 eyes (14.29%). One eye had intra- operative epithelial abrasion, and 1 eye had residual postoperative striae outside of the optical zone. Conclusion. The ?ap-sliding technique is a simple, noninvasive, e?cient, and safe technique for managing post-LASIK ?ap striae that develop after epithelial healing in the early post-LASIK period. This trial is registered with NCT04055337.
关键词： flap striae,flap-sliding technique,LASIK,corneal refractive surgery
更新于2025-09-23 15:19:57
-
COMPUTER-AIDED DECISION SYSTEM FOR REFRACTIVE SURGERIES WITH EXCIMER LASER
摘要： 124 patients (248 eyes) who intended to refractive surgery by Excimer laser were studied to implement our goal of this study which is design and operate a computer-aided decision system for optimal choosing the best refractive surgery based on patient needs, Starting from corneal topography and aberration images, using RGB and HSI color spaces and decision tree. The system also can calculate percent of vision correction, ablation and residual stroma with high precision. This highly important transdisciplinary topic combines aspects from biosystems (human visual system), image acquisition and processing and information management (databases).
关键词： Image Processing,Computer-Aided Decision System,Refractive Surgery,Decision Tree
更新于2025-09-23 15:19:57
-
Implantable inlay devices for presbyopia: the evidence to date
摘要： By 2020, it is estimated that 2.1 billion people will be presbyopic, and the demand for spectacle independence in this group is growing. This review article provides an overview of the three commercially available corneal inlays for the correction of presbyopia. Safety, efficacy, visual outcomes, and complications are analyzed for all three inlays according to published peer-reviewed data.
关键词： refractive surgery,corneal inlay,refractive optic inlay,presbyopia,corneal reshaping inlay,small-aperture inlay
更新于2025-09-19 17:15:36
-
Small-incision lenticule extraction in a patient with high astigmatism and nystagmus
摘要： Small-incision lenticule extraction (SMILE) was performed in a patient with high astigmatism and nystagmus. The patient presented for a refractive surgery evaluation with a manifest refraction of -0.50 -6.00 × 137 (20/40-1) in the right eye and -2.25 -2.25 × 30 (20/40-1) in the left eye. The patient was deemed suitable for corneal laser refractive surgery. Consideration was given to SMILE, laser in situ keratomileusis, and photorefractive keratectomy. It was decided SMILE was the best option given that the refractive portion of the procedure is performed while the cornea is immobilized by suction. The treatment was uneventful, and the final manifest refraction was +0.25 -0.25 × 130 (20/40) in the right eye and +0.25 diopter sphere (20/40) in the left eye. Topography was normal, showing a well-centered treatment zone. This case highlights an additional use for SMILE, given its ability to immobilize the cornea during treatment.
关键词： astigmatism,SMILE,refractive surgery,cornea immobilization,nystagmus
更新于2025-09-19 17:15:36
-
Total keratometry in intraocular lens power calculations in eyes with previous laser refractive surgery
摘要： Importance: Intraocular lens (IOL) calculations in post-refractive cases remain a concern. Our study identifies improved options for surgeons. Background: To evaluate and compare the prediction accuracy of IOL power calculation methods after previous laser refractive surgery using standard keratometry (SK), measured posterior corneal astigmatism (PCA) and total keratometry (TK). Design: Retrospective consecutive cohort Participants: 50 consecutive patients (72 eyes) at a private institution who underwent cataract surgery with prior laser refractive procedures Methods: Methods using SK included ASCRS mean, Barrett True K no history, Haigis-L and Shammas IOL formulae. Barrett True K using posterior values (True K TK), Haigis and Holladay 1 Double-K methods using TK were also assessed. Post-surgery refraction was undertaken at minimum 3 weeks following surgery. Main outcome measures: Arithmetic and absolute IOL refractive prediction errors, variances in mean arithmetic IOL prediction error, and percentage of eyes within ± 0.25D, ± 0.50D, ± 0.75D and ± 1.00D of refractive prediction errors were compared. Results: The Barrett True K (TK) provided the lowest mean refractive prediction error and variance for both prior myopes and hyperopes undergoing cataract surgery. The Barrett True K (TK) exhibited the highest percentages of eyes within ± 0.50D, ± 0.75D and ± 1.00D of the refractive prediction error compared to other formulae for prior myopic patients. Conclusions and relevance: Accuracy of IOL power calculations in post-laser eyes can be improved by the addition of posterior corneal values as measured by the IOLMaster 700. The use of total keratometry may supplement outcomes when no prior refraction history is known.
关键词： Cataract,Refractive surgery,Surgery,Intraocular lenses
更新于2025-09-19 17:13:59