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Six modes of corneal topography for evaluation of ablation zones after small-incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis
摘要： Purpose To evaluate the ablation zone diameter (AZD) using six modes of corneal topography after small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia and to compare the programmed and postoperative AZDs Methods This retrospective comparative study included 86 right eyes in 86 patients who underwent SMILE or FS-LASIK at the Shandong Eye Institute between June 2016 and August 2017. Data were collected preoperatively and at 1, 3, and 6 months postoperatively using the Pentacam system. The AZD was determined using six modes of corneal topography: postoperative axial curvature topography (PACT), postoperative tangential curvature topography (PTCT), difference-axial curvature topography (DACT), difference-tangential curvature topography (DTCT), postoperative front elevation topography (PFET), and difference-corneal thickness topography (DCTT). The difference between the programmed and postoperative AZDs was compared between the groups of two surgical procedures. Results At 3 months, the AZDs measured by PTCT, DTCT, and PFET after SMILE showed a significant decrease, while the AZD by DACT revealed an increase (P < 0.001), and the AZDs measured by PACT, PTCT, DACT, DTCT, PFET, and DCTT after FS-LASIK were all significantly decreased (P < 0.001), as compared with the programmed ablation zone values. The AZDs measured by DACT and DTCT after 3 months were larger in the SMILE group (P < 0.001); likewise, the differences between the programmed and postoperative AZDs were lower in the SMILE group (P < 0.001). Furthermore, PACT, PTCT, DACT, DTCT, and PFET indicated acceptable inter-observer reliability (ICC > 0.75). Conclusions In the treatment of myopia, the achieved topographic ablation zones after FS-LASIK were smaller than the theoretically designed ones. The AZDs after SMILE were larger than those after FS-LASIK, with an equivalent programmed value. The DACT may be more suitable for measuring postoperative ablation zones in clinic with clearer borders and favorable repeatability. This method may be potential for the measurement of ablation zones and further research on the visual quality after refractive surgery.
关键词： SMILE,FS-LASIK,Corneal topography,Ablation zone
更新于2025-09-23 15:21:01
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Laser-assisted in-situ keratomileusis (LASIK) with a mechanical microkeratome compared to LASIK with a femtosecond laser for LASIK in adults with myopia or myopic astigmatism
摘要： Laser-assisted in-situ keratomileusis (LASIK) is a surgical procedure that corrects refractive errors. This technique creates a flap of the outermost parts of the cornea (epithelium, bowman layer, and anterior stroma) to expose the middle part of the cornea (stromal bed) and reshape it with excimer laser using photoablation. The flaps can be created by a mechanical microkeratome or a femtosecond laser.
关键词： mechanical microkeratome,femtosecond laser,myopic astigmatism,LASIK,myopia
更新于2025-09-23 15:21:01
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Hyperopic laser keratorefractive surgery: Do steep corneas have worse outcomes?
摘要： Purpose To report the visual and refractive outcomes of hyperopic patients undergoing laser keratorefractive surgery in preoperatively steep corneas versus a matched control group. Methods Retrospective cohort study. All patients underwent photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK) at Care-Vision Laser Centers, Tel-Aviv, Israel, between 1/2000 and 11/2016. Patients were divided into two groups: steep corneas (mean keratometry C 44.00 D) and control group (mean keratometry < 44.00 D). The two study groups were matched by age, gender, sphere and cylinder. Only the right eye of each patient was included. Outcomes included postoperative uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (CDVA), safety and efficacy indexes, refractive outcomes and retreatment rates. Results Five hundred and two patients were included. Both groups were similar in demographic data, visual acuity and refraction. Postoperatively, the steep corneas group had a significantly higher mean keratometry as compared to the control group (46.52 ± 1.43 D vs 44.58 ± 1.68 D, p < 0.001), Kmin (46.04 ± 1.50 D vs 44.12 ± 1.76 D, p < 0.001) and Kmax (46.99 ± 1.51 D vs 45.03 ± 1.77 D, p < 0.001). Both groups had similar postoperative UDVA and CDVA and achieved a similar final sphere (0.64 ± 0.19 vs 0.54 ± 1.19, p = 0.44) and cylinder (-0.89 ± 0.59 vs -0.86 ± 0.72, p = 0.67). Both groups had a similar efficacy index (0.92 ± 0.22 vs 0.90 ± 0.25, p = 0.33) and similar retreatment rates (4.2% vs 3.5%, p = 0.74). None of the patients in either group underwent more than one retreatment throughout the follow-up period. Conclusions Hyperopic patients with steep corneas undergoing laser keratorefractive surgery can achieve adequate visual and refractive outcomes, similar to control group.
关键词： PRK,LASIK,Keratorefractive surgery,Hyperopia,Steep cornea
更新于2025-09-23 15:21:01
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Diffractive trifocal lens implantation with or without excimer laser enhancement: is a touch-up procedure a negative predictor for refractive and subjective outcome?
摘要： Purpose To investigate the refractive results of a LASIK enhancement and its impact on treatment safety, efficacy, predictability and patient reported outcome in eyes after clear lens extraction and diffractive trifocal lens implantation. Methods A retrospective cohort multicentre study of Care Vision Refractive Centres in Germany compared two groups of patients. Group 1 consisted of eyes that had non-toric MIOL surgery only, whereas group 2 had a consecutive laser enhancement after 3 months follow-up. Refractive and subjective results of the two groups were compared. Patient reported outcome measurements were assessed by using a 30-item questionnaire with four subscales. (Spectacle Dependence, Eye Comfort, Freedom and Looking/Feeling Well). Refractive results were reported following standard reporting in refractive surgery. Results 139 eyes of 79 patients were included in which either MIOL surgery or MIOL surgery plus LASIK enhancement had been performed between January and December 2017. UDVA reached 0.1logMAR (0.8; 20/25) in 94% in group 2 and 85% in group 1. Compared to preoperative CDVA no change in Snellen lines of CDVA was shown in 89% in group 1 and in 93% in group 2. Spectacle dependence (P = 0.41), eye comfort (P = 0.15), freedom (P = 0.48) and looking/feeling well (P = 0.45) showed no statistically significant difference between both the groups. Conclusions In patients with residual ametropia after MIOL implantation, LASIK provides a reliable, safe and efficient way to achieve the desired refractive outcome and patient satisfaction. We recommend performing Laser enhancement at 3 months after MIOL implantation (Bioptics) in trifocal MIOL patients that benefit from improvement of residual ametropia.
关键词： Touch-up procedure,LASIK,Laser enhancement,MIOL-implantation
更新于2025-09-23 15:19:57
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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
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Microvascular changes in macula and optic nerve head after femtosecond laser-assisted LASIK: an optical coherence tomography angiography study
摘要： To measure the microcirculation change of macula and optic nerve head before and after femtosecond laser assisted laser in situ keratomileusis. In total 45 eyes from 45 subjects, who underwent FS-LASIK during June 2017 to December 2017 in Guangdong Provincial People’s Hospital, were recruited in this study. Vessel density in macula and optic nerve head were measured by optical coherence tomography angiography before and after transient elevation in intraocular pressure caused by application of suction ring during surgery. Vessel density (VD) at superficial (SCP) plexus of macular region did not differ after surgery (F(3,132) = 1.41, P = 0.24), while the deep (DCP) plexus of macular region significantly decreased 1 day after surgery (P = 0.001) but returned to its baseline value 1 month postoperatively (P = 0.1). Vessel density of optic nerve head region had no significant changes after surgery (F(2.51,95.18) = 0.6, P = 0.59). A short-term temporary decrease of vessel density at deep layer of macular region was observed in eyes undergoing FS-LASIK. However, the retinal capillary density went back to preoperative level 1 month after surgery. Therefore, transient IOP spike during FS-LASIK did not cause long-term decline of retinal microcirculation.
关键词： Optical coherence tomography angiography,Femtosecond laser-assisted LASIK,Microvascular changes,Macula,Optic nerve head
更新于2025-09-23 15:19:57
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Five-year outcomes of small-incision lenticule extraction vs femtosecond lasera??assisted laser in situ keratomileusis
摘要： To compare the long-term refractive and visual outcomes and the corneal higher-order aberrations of contralateral eyes of patients who received small-incision lenticule extraction (SMILE) in one eye and femtosecond laser–assisted laser in situ keratomileusis (FS-LASIK) in the other eye.
关键词： small-incision lenticule extraction,femtosecond laser–assisted laser in situ keratomileusis,myopic astigmatism,corneal higher-order aberrations,SMILE,FS-LASIK,myopia
更新于2025-09-19 17:13:59
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Refractive outcomes comparing small-incision lenticule extraction and femtosecond lasera??assisted laser in situ keratomileusis for high myopia
摘要： To compare the long-term refractive effects of small-incision lenticule extraction (SMILE) and femtosecond laser–assisted laser in situ keratomileusis (FS-LASIK) on the correction of high myopia and astigmatism.
关键词： refractive surgery,SMILE,FS-LASIK,high myopia,astigmatism
更新于2025-09-19 17:13:59
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Traumatic laser in situ keratomileusis flap dislocation with epithelial ingrowth, Propionibacterium acnes infection, and diffuse lamellar keratitis
摘要： Rationale: Traumatic ?ap dislocation might occur anytime after laser in situ keratomileusis (LASIK), but it is rarely concomitantly complicated with epithelial ingrowth, infectious keratitis, and diffuse lamellar keratitis altogether. Here we report a case of traumatic LASIK ?ap inversion with epithelial ingrowth, Propionibacterium acnes infection, and diffuse lamellar keratitis. Patient concerns: A 42-year-old man receiving bilateral LASIK surgery 10 years ago complained of right eye pain for 6 days after twig injury. Temporal ?ap inversion with epithelial ingrowth and dense in?ltration at the interface were noted. Diagnoses: Traumatic LASIK ?ap inversion with epithelial ingrowth, Propionibacterium acnes infection and diffuse lamellar keratitis. Interventions: Removal of corneal epithelium around the ?ap inversion site, ?ap lifting, scraping of epithelial ingrowth, removal of the dense in?ltrate, alcohol soaking, interface irrigation with antibiotics, and ?ap reposition were performed. Diffuse lamellar keratitis was noted postoperatively. Culture of the in?ltrate revealed P acnes. The in?ltrate subsided and the cornea cleared up under topical antibiotics and steroid. Outcomes: The visual acuity returned to 20/20. No recurrent epithelial ingrowth or in?ltrate was noted during the follow-up. Lessons: This is the ?rst report of Propionibacterium acnes keratitis after traumatic ?ap inversion. Although epithelial ingrowth, infectious keratitis, and diffuse lamellar keratitis all developed after the ?ap inversion, early recognition and proper intervention lead to a good result without sequels.
关键词： Propionibacterium acnes,?ap dislocation,LASIK,infectious keratitis,diffuse lamellar keratitis,case report,epithelial ingrowth
更新于2025-09-19 17:13:59
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Differences in Simulated Refractive Outcomes of Photorefractive Keratectomy (PRK) and Laser In-Situ Keratomileusis (LASIK) for Myopia in Same-Eye Virtual Trials
摘要： The use of computational mechanics for assessing the structural and optical consequences of corneal refractive procedures is increasing. In practice, surgeons who elect to perform PRK rather than LASIK must often reduce the programmed refractive treatment magnitude to avoid overcorrection of myopia. Building on a recent clinical validation study of finite element analysis (FEA)-based predictions of LASIK outcomes, this study compares predicted responses in the validated LASIK cases to theoretical PRK treatments for the same refractive error. Simulations in 20 eyes demonstrated that PRK resulted in a mean overcorrection of 0.17 ± 0.10 D relative to LASIK and that the magnitude of overcorrection increased as a function of attempted correction. This difference in correction closely matched (within 0.06 ± 0.03 D) observed differences in PRK and LASIK from a historical nomogram incorporating thousands of cases. The surgically induced corneal strain was higher in LASIK than PRK and resulted in more forward displacement of the central stroma and, consequently, less relative flattening in LASIK. This FE model provides structural confirmation of a mechanism of action for the difference in refractive outcomes of these two keratorefractive techniques, and the results were in agreement with empirical clinical data.
关键词： laser in situ keratomileusis (LASIK),refractive surgery,cornea,photorefractive keratectomy (PRK),finite element analysis
更新于2025-09-16 10:30:52