scholarly journals Implantable collamer lens for residual refractive error after corneal refractive surgery

2016 ◽  
Keyword(s):  
Refractive Error ◽  
Refractive Surgery ◽  
Implantable Collamer Lens ◽  
Corneal Refractive Surgery

scholarly journals Implantable collamer lens with a central hole for residual refractive error correction after corneal refractive surgery

2019 ◽  
Author(s):  
Zhang Jing ◽  
Zhenzhen Zhang ◽  
Zhu Yi ◽  
DongQin Zhu ◽  
Fan Xianqun
Keyword(s):  
Visual Acuity ◽  
Error Correction ◽  
Refractive Error ◽  
Refractive Surgery ◽  
Cutoff Frequency ◽  
Strehl Ratio ◽  
Implantable Collamer Lens ◽  
Corneal Refractive Surgery ◽  
Icl V4c ◽  
The Mean

Abstract PURPOSE: To assess the visual and refractive outcomes of an implantable collamer lens with a central hole (ICL V4c) for residual refractive error correction after corneal refractive surgery in individuals with myopia. DESIGN: Prospective, nonrandomized observational case series (self-controlled). METHODS: We investigated 16 eyes of eight consecutive patients with myopia undergoing ICL V4c implantation after corneal refractive surgery. The uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were examined before surgery and 1 month, 3 months, and 6 months after surgery. We quantitatively assessed the postoperative values of the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs) by using an Optical Quality Analysis System. RESULTS: At 6 months after surgery, the mean uncorrected logMAR VA was 0.06 ± 0.10, and the values had improved in 100% of the eyes. The mean MTF cutoff frequency, Strehl ratio, OSI, OV 100%, OV 20%, and OV 9%, were 31.29 ± 4.32 cycles/degree (c/d), 0.18 ± 0.04, 1.469 ± 0.47, 0.97 ± 0.26, 0.75 ± 0.29, and 0.51 ± 0.23 at 6 months after ICL V4c implantation, respectively. CONCLUSION: ICL V4c implantation was safe and effective for the correction of residual refractive error after corneal refractive surgeries, and it had excellent optical performance.

scholarly journals Effect of corneal refractive surgery on accommodative and binocular dysfunctions among civilian pilots in Southwest China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ye Wu ◽  
Zhen Zhang ◽  
Meng Liao ◽  
Qi Li ◽  
Xue Lin Tang ◽  
...  
Keyword(s):  
Binocular Vision ◽  
Refractive Surgery ◽  
Visual Symptom ◽  
Chi Square ◽  
Visual Symptoms ◽  
Significant Difference ◽  
Symptom Scores ◽  
Chi Square Test ◽  
Corneal Refractive Surgery ◽  
Normal Binocular Vision

Abstract Background To analyze whether corneal refractive surgery (CRS) is associated with the distribution of different accommodative dysfunctions (ADs) and binocular dysfunctions (BDs) in civilian pilots. A further aim was to analyze the percentages and visual symptoms associated with ADs and/or BDs in this population. Methods One hundred and eight civilian pilots who underwent CRS from January 2001 to July 2012 (age: 30.33 ± 4.60 years) were enrolled, the mean preoperative SE was − 1.51 ± 1.15 D (range: − 1.00- − 5.00 D). Ninety-nine emmetropic civilian pilots (age: 29.64 ± 3.77 years) who were age- and sex-matched to the CRS group were also enrolled. Refractive status, accommodative and binocular tests of each subject were performed. Visually related symptoms were quantified using the 19-item College of Optometrists in Vision Development Quality of Life (COVD-QOL) questionnaire. The 19 items were summed to obtain visual symptom scores that might indicate visual dysfunctions. The chi-square test was used to analyze differences in percentages of ADs and/or BDs between the CRS and emmetropic groups. The Mann-Whitney U test was used to compare visual symptom scores between pilots with ADs and/or BDs and pilots with normal binocular vision. Results No significant difference was observed between the CRS and emmetropic groups in the overall prevalence of ADs and BDs (15.7% and 15.2% in the CRS and emmetropic groups, respectively; P = 0.185). ADs were present in 4.63% and 3.03% of the CRS and emmetropic group, respectively. BDs were observed in 11.1% and 12.1% of the CRS and emmetropic group, respectively, yielding no significant differences between the groups in the prevalence of ADs or BDs (AD: P = 0.094; BD: P = 0.105). Pilots with ADs and/or BDs had significantly more visual symptoms than pilots with normal binocular vision (p < 0.001). Conclusions CRS for civilian pilots with low-moderate myopia might not impact binocular functions. ADs and/or BDs commonly occur in both emmetropia pilots and pilots who undergo CRS, and pilots with ADs and/or BDs are associated with increased symptoms. This study confirms the importance of a full assessment of binocular visual functions in detecting and remedying these dysfunctions in this specific population.

Constitutive Laws for Biomechanical Modeling of Refractive Surgery

1996 ◽  
Vol 118 (4) ◽  
pp. 473-481 ◽  
Author(s):  
Michael R. Bryant ◽  
Peter J. McDonnell
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Refractive Surgery ◽  
Fiber Optic ◽  
Transverse Isotropy ◽  
Constitutive Laws ◽  
Finite Element Models ◽  
Corneal Refractive Surgery ◽  
Best Fit ◽  
Membrane Inflation

Membrane inflation tests were performed on fresh, intact human corneas using a fiber optic displacement probe to measure the apical displacements. Finite element models of each test were used to identify the material properties for four different constitutive laws commonly used to model corneal refractive surgery. Finite element models of radial keratotomy using the different best-fit constitutive laws were then compared. The results suggest that the nonlinearity in the response of the cornea is material rather than geometric, and that material nonlinearity is important for modeling refractive surgery. It was also found that linear transverse isotropy is incapable of representing the anisotropy that has been experimentally measured by others, and that a hyperelastic law is not suitable for modeling the stiffening response of the cornea.

Ocular surface diseases and corneal refractive surgery

2014 ◽  
Vol 25 (4) ◽  
pp. 264-269 ◽  
Author(s):  
Debora Garcia-Zalisnak ◽  
David Nash ◽  
Elizabeth Yeu
Keyword(s):  
Ocular Surface ◽  
Refractive Surgery ◽  
Ocular Surface Diseases ◽  
Corneal Refractive Surgery

Decompensation of Exodeviation After Corneal Refractive Surgery for Moderate to High Myopia

2003 ◽  
Vol 34 (5) ◽  
pp. 363-370
Author(s):  
Moshe Snir ◽  
Israel Kremer ◽  
Dov Weinberger ◽  
Ilana Sherf ◽  
Ruth Axer-Siegel
Keyword(s):  
High Myopia ◽  
Refractive Surgery ◽  
Corneal Refractive Surgery
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