Journal of refractive surgery最新文献

Purpose: To conduct a critical review of the peer-reviewed literature on the use of an implantable collamer lens (ICL) for the correction of pseudophakic ametropia.

Methods: A scoping review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the National Library of Medicine (PubMed), EMBASE, and Web of Science as the primary source of information. Articles were selected based on predefined inclusion and exclusion criteria for this review, ultimately resulting in the selection of 17 articles for the current scoping review.

Results: Data from 170 eyes of 147 patients were analyzed. Most of the reviewed studies exhibited short follow-up periods and had suboptimal designs, including case reports and case series with lack of clinical trials. However, most authors report that visual performance and refractive outcomes were significantly improved for all patients undergoing surgery, leading to enhanced postoperative uncorrected distance visual acuity with a very low complication rate.

Conclusions: The use of the ICL, both spherical and toric, as a supplementary intraocular lens for correcting pseudophakic ametropia represents a viable option for enhancing vision and improving patient satisfaction, with minimal associated complications. Nevertheless, further research with more robust study designs is necessary to validate these findings.

Purpose: To describe a new surgical technique to treat corneal allogenic ring segments (CAIRS) shaped by a femto-second laser with extracorporeal ultra-high-fluence corneal cross-linking (CXL) before insertion into the corneal stroma (ECO-CAIRS).

Methods: Four eyes from four patients with stable keratoconus and maximum keratometry readings between 58.00 and 69.80 diopters (D) were analyzed. Each patient had a corneal thickness of at least 400 μm at 5 mm from the pupil center. CAIRS were prepared from donor corneas using a femtosecond laser. The segments were cross-linked with 30 and 60 J/cm² ultraviolet (UV) light fluences, and inserted without air-drying or extended dehydration.

Results: Insertion was uneventful in all cases. CAIRS subjected to ultra-high-fluence CXL remained stiff during the entire insertion process and showed no tendency to soften. The initial ring segment thickness was approximately halved immediately after the high-fluence CXL treatment compared to pre-CXL levels; thickness levels increased within days after insertion.

Conclusions: This new technique may provide multiple advantages over unmodified or air-dried CAIRS, including an easier insertion due to greater stiffness and resistance to re-swelling during insertion. The high UV fluences used should eliminate viable keratocytes, essentially transforming the segment into an acellular collagen scaffold. Finally, the marked transitory decrease in thickness may allow for the insertion of ring segments with greater overall volume, potentially increasing the corneal topographical effect. Further clinical research is required to assess the extent to which the effect on corneal topography is driven by the CAIRS volume and/or by its intrinsic stiffness.

Purpose: To evaluate visual performance of a novel full range of vision spiral intraocular lens (IOL) designed with artificial intelligence using preclinical and clinical metrics.

Methods: Preclinical visual performance was assessed in healthy individuals using a pseudophakic vision simulation device, comparing monocular corrected distance visual acuity, contrast sensitivity, defocus curve, halo/glare size, and subjective preference between the spiral RayOne Galaxy IOL and diffractive RayOne Trifocal IOL (Rayner). Additionally, postoperative clinical outcomes were subsequently analyzed from 10 sites following bilateral RayOne Galaxy IOL implantation. At 3 months postoperatively, key endpoints included subjective refraction, monocular and binocular uncorrected and corrected distance visual acuity at multiple distances, defocus curves, and patient-reported dysphotopsia.

Results: Preclinical evaluation demonstrated comparable range of focus between the Galaxy and diffractive Trifocal IOLs. However, the Galaxy IOL exhibited significantly less halo/glare, with nearly all participants preferring it across all distances. In the clinical study, mean monocular corrected distance visual acuities were -0.03 ± 0.08 logarithm of the minimum angle of resolution (logMAR) for distance, 0.05 ± 0.11 logMAR for intermediate, and 0.08 ± 0.14 logMAR for near, with further improvement observed binocularly. Monocular/binocular defocus curves demonstrated a smooth plateau with binocular defocus maintaining visual acuity of 20/32 (0.2 logMAR) or better from +1.00 to -2.80 diopters (35 cm). Halo and glare symptoms were generally minor (> 95% of patients), with no severe cases.

Conclusions: The Galaxy IOL provides excellent monocular and binocular visual acuity across all tested distances, with a smooth and continuous defocus curve ensuring full-range vision. Preclinical testing demonstrated significantly fewer photic phenomena than the tested diffractive trifocal IOL, whereas clinical investigations found no indications of bothersome side effects, together demonstrating high visual comfort.

Purpose: To evaluate the prevalence of satisfaction, dissatisfaction, and intolerance after presbyopia-correcting intraocular lens (PrC-IOL) implantation, identify primary causes of dissatisfaction, and assess the rate of spontaneous resolution of photic phenomena in a clinical setting.

Methods: This was a retrospective cross-sectional study of consecutive patients who had PrC-IOL implantation, including bifocal (ReSTOR; Alcon Laboratories, Inc), trifocal (Pan-Optix; Alcon Laboratories, Inc), diffractive extended depth-of-focus (EDOF) (Symfony; Tecnis), and non-diffractive EDOF (Vivity; Alcon Laboratories, Inc), at the Cole Eye Institute, Cleveland Clinic between January 2017 and December 2022. Evaluated variables included refractive outcomes, patient-reported satisfaction/dissatisfaction or intolerance, primary drivers of dissatisfaction, management strategies, IOL exchange rates, and spontaneous resolution of photic phenomena over time.

Results: A total of 493 patients (970 eyes) were evaluated. Overall, 87.2% reported satisfaction with their IOL outcomes, with 38% experiencing photic phenomena in the early follow-up. Dissatisfaction occurred in 12.8% of patients, with 7.7% of the total cohort reporting IOL intolerance. Blurry corrected vision (73%) and photic phenomena (50.8%) were the most common causes of dissatisfaction. Compared to satisfied patients, dissatisfied and intolerant patients had worse refractive outcomes and higher rates of photic phenomena. Among patients reporting photic phenomena at their initial stability visit and completing 1 year of follow-up, 43% experienced spontaneous resolution, most between 6 and 12 months. IOL exchange was performed in 2.4% of patients.

Conclusions: Most patients were satisfied with PrC-IOLs; however, in this analysis 12.8% reported dissatisfaction and 7.7% were intolerant to the lenses. Blurry corrected vision and photic phenomena were the leading causes of dissatisfaction. Spontaneous resolution of photic phenomena occurred in approximately one-third of cases but is less frequent among dissatisfied patients. IOL exchange may be necessary to alleviate symptoms.

Purpose: To critically reassess the scientific foundation of the 400-μm minimum corneal thickness threshold for endothelial safety in standard corneal cross-linking (CXL) with 3 mW/cm² ultraviolet A (UVA) irradiation.

Methods: A comprehensive analysis of the foundational studies that established this limit was conducted, with a focus on their methodological assumptions, modeling strategies, and translational weaknesses. Particular attention was given to the use of optical attenuation equations, riboflavin pharmacokinetics, and evolving imaging practices.

Results: The 400-μm threshold is derived from two seminal studies (one in vitro, one in vivo) that applied fixed assumptions about riboflavin concentration and stromal uniformity. Notably, the models used the Exponential Attenuation law and not the Lambert-Beer law, as opposed to what is frequently cited, to estimate UVA penetration. These estimations relied on simplified optical parameters, such as a uniform attenuation coefficient (μ = 53 cm^-1), without accounting for depth-dependent chromophore gradients, scattering, or biological variability. Moreover, the original threshold did not anticipate subsequent changes in riboflavin formulation and concentration, the use of alternative vehicles such as hydroxypropyl methylcellulose, or the emergence of accelerated and customized CXL protocols-factors that materially alter stromal pharmacokinetics and photochemical response.

Conclusions: The 400-μm guideline, although historically influential, is conceptually fragile. To establish a scientifically robust safety threshold in CXL, future models must incorporate validated attenuation coefficients, experimentally defined riboflavin diffusion dynamics, and patient-specific stromal properties. A more precise, data-driven framework is needed to support individualized decision-making, especially for CXL in thin corneas.

Purpose: To analyze the impact of keratometry, axial length (AL), anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), and white-to-white distance (WTW) on the predictive accuracy of formulas included in the European Society of Cataract and Refractive Surgery (ESCRS) IOL power calculator.

Methods: This retrospective case series included 748 eyes from 748 patients. Postoperative refraction data were used to calculate refractive prediction errors (PEs) for the Barrett, Cooke K6, EVO, Hill-RBF, Hoffer QST, Kane, and Pearl-DGS formulas. Low, medium, and high subgroups were created based on the value of selected anatomical parameters. Statistical analysis included standard deviation, root mean square absolute errors (RMSAE), and stepwise multiple regression.

Results: Significant differences in formula performance were observed across subgroups. The Hoffer QST had a higher standard deviation than the Cooke K6, Kane, and Pearl-DGS in the subgroup with steep keratometry and a higher standard deviation than the Pearl-DGS in the subgroup with thin LT. The Kane had a lower standard deviation than the Cooke K6 in the subgroup with shallow ACD and a lower RMSAE than the EVO in the subgroup with deep ACD. The Cooke K6 had a lower standard deviation than the Hoffer QST in the subgroup with deep ACD. Anatomical parameters that significantly contributed to the PEs were: keratometry for the Pearl-DGS; AL for all formulas except the Hill-RBF; ACD for the Hill-RBF and Hoffer QST; LT for the Hill-RBF, Hoffer QST, and Pearl-DGS; CCT for the Pearl-DGS; and WTW for the Barrett and Kane.

Conclusions: Anatomical parameters significantly influence the accuracy of modern IOL power calculation formulas. These findings suggest that tailoring formula selection based on specific anatomical characteristics can improve refractive outcomes in cataract surgery.

Purpose: To assess the safety and effectiveness of sequential customized transepithelial phototherapeutic keratectomy (SCTK) performed after meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) in patients with advanced keratoconus, with a focus on higher order aberrations (HOAs), corrected distance visual acuity (CDVA), and corneal biomechanics.

Methods: This prospective interventional study included patients previously treated with MS-SLAK for advanced keratoconus, showing corneal HOAs 3 μm or greater at a 4-mm pupil diameter and at least 200 μm of stromal thickness anterior to the implanted lenticule. All patients underwent SCTK using excimer laser ablation based on the corneal aberrometer, treating HOAs. Two sequential customized SCTK ablations were performed with intraoperative topographic reassessment. Patients were evaluated at baseline and at 3, 6, and 12 months postoperatively. Parameters included CDVA, manifest refraction spherical equivalent, corneal and ocular wavefront, tomographic data, and dynamic corneal response measurements.

Results: Six eyes from six patients were analyzed. The procedure resulted in significant visual improvement, with median spectacle CDVA improving from 20/125 to 20/32 at 12 months (P = .0001), and median contact lens CDVA reaching 20/25. HOAs significantly decreased, particularly root mean square (RMS) coma (from 3.3 (1.6) to 1.0 (0.5) μm, P = .02) and ocular RMS HOA (from 4.1 (1.8) to 1.8 (0.4) μm, P = .03). Corneal biomechanics remained stable throughout follow-up, with no signs of ectasia.

Conclusions: SCTK following MS-SLAK seems an effective sequential treatment strategy in advanced keratoconus. Combining biomechanical reinforcement with optical surface regularization enhances visual function and reduces HOAs, and could offer a viable alternative to corneal transplantation in selected cases.

Purpose: To compare 12-month visual outcomes, higher order aberrations (HOAs), epithelial remodeling patterns, and patient-reported outcomes (PROs) between topography-guided laser in situ keratomileusis (TG-LASIK) and keratorefractive lenticule extraction (KLEx).

Methods: Forty patients (80 eyes) underwent TG-LASIK in one eye and KLEx in the fellow eye for myopia with and without astigmatism. Preoperative and up to 12-month evaluations included uncorrected distance visual acuity (UDVA), corrected distance visual acuity, contrast sensitivity, HOAs, corneal epithelial analysis, corneal hysteresis (CH), corneal resistance factor (CRF), and PROs.

Results: At 1 year, all eyes achieved a UDVA of 20/20 or better. Spherical equivalent (SEQ) stability did not differ between groups. TG-LASIK showed better contrast sensitivity than KLEx at 1 month (P < .001), which became comparable by 3 months. KLEx had more undercorrected cylinder than TG-LASIK at 12 months (P = .033), with 97.5% of TG-LASIK and 85% of KLEx eyes achieving a residual cylinder of 0.50 diopters or less (P = .02). KLEx induced higher vertical coma (P < .001), whereas spherical aberration remained statistically unchanged in both groups. By 1 month, KLEx removed 2.5 ± 3.4 μm/diopter more stromal tissue (P < .001); however, epithelial remodeling within the 2- and 5-mm zones compensated for this loss by 1 year. The decline in CH and CRF postoperatively was similar between platforms (P > .05). At 12 months, there was no difference in subjective and objective dry eye symptoms between groups.

Conclusions: KLEx resulted in greater vertical coma, stromal consumption per diopter, and undercorrected cylinder. Although early differences in PROs, eye preference, and contrast sensitivity transiently favored TG-LASIK, both procedures were comparable in terms of stability, predictability, CH, CRF, and patient satisfaction at 12 months.