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

scholarly journals Changes in Effective Optical Zone After Small-Incision Lenticule Extraction in High Myopia

2022 ◽  
Author(s):  
Lixia Sun ◽  
Hui-Ni Lin ◽  
Vishal Jhanji ◽  
Tsz Kin Ng ◽  
Rui-feng Ji ◽  
...  
Keyword(s):  
High Myopia ◽  
Refractive Surgery ◽  
Southern China ◽  
Full Characterization ◽  
Corneal Aberrations ◽  
Refraction Method ◽  
Significant Difference ◽  
Corneal Refractive Surgery ◽  
Optical Zone ◽  
The Difference

Abstract Purpose: To evaluate the four measurement approaches on the determination of effective optical zone (EOZ) using Scheimpflug tomography after SMILE surgery in eyes with high myopia.Setting: Corneal refractive surgery conducted in eye hospital in southern ChinaDesign: A retrospective cohort study.Methods: Total 74 subjects were recruited. EOZ was measured at 3 months postoperatively using Vertex-Based total corneal refraction method (EOZV), pupil-based total corneal refraction method (EOZP), 4 mm-Ring-Based total corneal refraction method (EOZ4), and axial curvature difference map (EOZD), and their consistencies were compared. EOZs and planned optical zone (POZ) were compared and analyzed with eccentricity, ablation degree (AD) and total corneal aberrations.Results: Mean AD was -6.87 ± 0.75 D, and eccentricity was 0.30 ± 0.17 mm. At 3 months after surgery, the mean root mean square of ΔHOA, ΔComa, ΔTrefoil and ΔSA were 0.53 ± 0.27 μm, 0.36 ± 0.20 μm, 0.01 ± 0.84 μm, and, 0.16 ± 0.14 μm respectively. EOZV, EOZP, EOZ4 and EOZD were 5.87 ± 0.44 mm, 5.85 ± 0.45 mm, 4.78 ± 0.40 mm, 5.29 ± 0.27 mm respectively, which were significantly smaller than POZ 6.48 ± 0.16 mm. Bland Altman plots showed a good consistency between the four EOZs. The difference between the EOZV and EOZP was 0.02 mm within the range of clinically acceptable difference. In addition, EOZD was positively correlated with AD, and the eccentricity was positively correlated with ΔHOA, ΔComa and ΔSA.Conclusions: All 4 measurement approaches demonstrated the reduction of EOZs compared to POZ. EOZV was the closest to POZ, followed by EOZP. ΔEOZs showed no significant difference with eccentricity, AD and corneal aberrations. Our results are useful for the full characterization of corneal treatment profiles after kerato-refractive surgery.

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

A quality of life assessment of military recruits after refractive surgery

2020 ◽  
Vol 1 (1) ◽  
pp. 42-46
Author(s):  
Jian-He Xiao ◽  
◽  
Shi-Yang Li ◽  
Xing Xing ◽  
Ai-Hong Zhao ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Refractive Error ◽  
High Myopia ◽  
Refractive Surgery ◽  
Laser In Situ Keratomileusis ◽  
Significant Difference ◽  
Lenticule Extraction ◽  
Postoperative Interval

AIM: To evaluate the quality of life of recruits after refractive surgery. METHODS: Population-based, cross-sectional study. Using the Quality of Life Impact of Refractive Correction (QIRC) questionnaire, the quality of life in 615 recruits underwent refractive surgery was evaluated. The overall score and each question score of QIRC were compared between subgroups of different strength of preoperative refractive error, postoperative interval, type of surgical procedure and postoperative recovery. RESULTS: The mean overall QIRC score of recruits underwent refractive surgery was 49.15±7.89. Significant difference was found for strength of preoperative refractive error (F=4.16, P<0.05), with the low myopia group (50.67±7.59) had significantly better scores than those with high myopia (47.57±7.52, F=4.16, P<0.05). Recruits after a postoperative interval no more than 6mo (49.18±7.86) scored equally to those of more than 6mo (49.18±8.03). Recruits underwent surface ablation surgery scored lowest (46.68±6.09), but showed no significant difference when compared with all underwent refractive surgery (t=1.99, P>0.05). Scores of recruits underwent mechanical microkeratome laser in situ keratomileusis (MK-LASIK), Sub-Bowman’s keratomileusis (SBK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), femtosecond lenticule extraction (ReLEx flex) or small-incision lenticule extraction (ReLEx SMILE) procedure showed no significant difference too. Recruits had adverse complaints postoperatively (45.85±6.66) scored lower when compared with all underwent refractive surgery (t=5.28, P<0.01). CONCLUSION: The quality of life of recruits after refractive surgery was good except those with postoperative complications. Preoperative low myopia recruits had better quality of life than medium and high myopia ones.

Equation for Corneal Asphericity After Corneal Refractive Surgery

2003 ◽  
Vol 19 (1) ◽  
pp. 65-69
Author(s):  
José R Jiménez ◽  
Rosario G Anera ◽  
Luis Jiménez del Barco
Keyword(s):  
Refractive Surgery ◽  
Corneal Asphericity ◽  
Corneal Refractive Surgery
Sign in / Sign up

Export Citation Format

Share Document