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.

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

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.

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

2020 ◽  
Author(s):  
Ye Wu ◽  
Zhen Zhang ◽  
Meng Liao ◽  
Qi Li ◽  
XueLin Tang ◽  
...  
Keyword(s):  
Binocular Vision ◽  
Refractive Surgery ◽  
Visual Symptom ◽  
Chi Square ◽  
Visual Symptoms ◽  
Vision Development ◽  
Significant Difference ◽  
Symptom Scores ◽  
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.

scholarly journals New avenues of preoperative evaluation before corneal refractive surgery during the COVID-19 pandemic

2021 ◽  
Vol 21 (2) ◽  
pp. 72-77
Author(s):  
S.N. Sakhnov ◽  
◽  
O.A. Klokova ◽  
A.V. Piskunov ◽  
R.O. Damashauskas ◽  
...  
Keyword(s):  
Refractive Surgery ◽  
Preoperative Evaluation ◽  
Corneal Thickness ◽  
Diagnostic System ◽  
Spherical Equivalent ◽  
Mean Values ◽  
Applanation Tonometer ◽  
Corneal Refractive Surgery ◽  
The Difference

Aim: to assess the reproducibility and comparability of measurements produced by Visionix VX130+ and their consistency with data produced by Topcon KR-800, NT-530P, Oculyzer, and RTVue-100. Patients and Methods: 124 patients (248 eyes) aged 18–45 years (mean age 25.24±7.5 years) were enrolled. Refractometry, IOP levels, and pachymetry measured by Visionix VX130+ system (LLC “Visionix Rus” — affiliated company of Luneau Technology Operations) were compared to the readings produced by Topcon KR-800 Auto Kerato-Refractometer (Topcon, Japan), Nidek NT-530P non-contact tonometer (Nidek, Japan), CT200 Goldman applanation tonometer (Reichert, USA), ALLEGRO Oculyzer (WaveLight AG, Germany), and RTVue-100 (Optovue, USA). Results: refractometry produced by Visionix VX130+ is highly reproducible and stable. Mean spread of spherical equivalent was 0.22±0.22 D and mean spread of cylindrical equivalent was 0.23±0.16 D. No significant differences were revealed between refractometry readings produced by Visionix VX130+ and Topcon KR-800 in patients with myopia (p>0.05). Both Visionix VX130+ and Nidek NT-530P (automated IOP measurements) produce two values, i.e., with and without corneal thickness. Our findings suggest that mean values are virtually similar in Visionix VX130+ group (p>0.05) while Nidek NT-530P produces significant differences (p<0.05). Mean central corneal thickness (CCT) measured by Visionix VX130+ was almost similar to CCT measured by Oculyzer (the difference was 3.8±2.23 μm, р>0.05) and greater than CCT measured by RTVue-100 (р<0.05). Conclusion: clinical trials comparing the readings produced by Visionix VX 130+ and other devices whose reliability was evidenced by long-term clinical experience have demonstrated that Visionix VX 130+ multifunctional diagnostic system is fully in line with the COVID-19 pandemic requirements. This device provides the measurements for performing safe and effective corneal refractive surgery for refractive errors. Keywords: corneal refractive procedure, pneumotonometry, aberrometry, corneal topography, pachymetry, cornea, intraocular pressure. For citation: Sakhnov S.N., Klokova O.A., Piskunov A.V. et al. New avenues of preoperative evaluation before corneal refractive surgery during the COVID-19 pandemic. Russian Journal of Clinical Ophthalmology. 2021;21(2):72–77. DOI: 10.32364/2311-7729-2021-21-2-72-77.

scholarly journals Correlation between central corneal thickness and intraocular pressure in various age groups

2010 ◽  
Vol 138 (5-6) ◽  
pp. 279-286 ◽  
Author(s):  
Ivan Marjanovic ◽  
Djordje Kontic ◽  
Paraskeva Hentova-Sencanic ◽  
Vujica Markovic ◽  
Marija Bozic
Keyword(s):  
Intraocular Pressure ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Age Groups ◽  
The Third ◽  
Significant Difference ◽  
Applanation Tonometer ◽  
Corneal Refractive Surgery ◽  
Piezoelectric Pressure Sensor

Introduction The Pascal Dynamic Contour Tonometer (DCT) is an ophthalmic investigational device which directly calculates the dynamic pulsatile fluctuations in intraocular pressure (IOP) using a piezoelectric pressure sensor embedded in the devices tip. Objective The aim of this study was to compare IOP results obtained with Goldmann applanation tonometer (GAT), and their correlation with central corneal thickness (CCT) in patients of various age groups. Methods We studied 37 patients (17 male and 20 female), divided into three age groups: younger than 40 years; 40-60 years old, and older than 60 years. In the first and second group there were patients rarely and in the third mostly diagnosed and medicamentously compensated glaucoma. In topical anesthesia, first we measured CCT, with ultrasound pachimeter, then IOP with DCT and GAT. Results Statistically significant difference between measurements of IOP with the DCT and GAT appeared in all groups: I mean diff. -1.71?}1.27 mm; p<0.0001; II mean diff. -1.19?}1.06 mm; p<0.0001; III mean diff. -1.69?}1.67 mm; p<0.0001. CCT was in indirect correlation with the values of IOP measured both with the DCT and GAT in the first and third, while it was in the direct correlation with these values in the second group. Conclusion CCT had no influence on IOP measurements both with the DCT and GAT in none of the groups. The DCT cannot replace GAT, but it is a reliable device for the measurement of IOP particularly in corneal deformations (keratoconus, after corneal refractive surgery, corneal scars, etc.). .

scholarly journals Comparison of Higher-Order Aberration Values between Different Aberrometry Technologies in Preoperative Laser Refractive Surgery Patients

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Md Muziman Syah ◽  
Khairidzan Mohd Kamal ◽  
Najwa Munirah Mohd Yusof ◽  
Aminul Hakim Sofian Sauri ◽  
Noor Atikah Mad ◽  
...  
Keyword(s):  
Refractive Surgery ◽  
Spherical Aberration ◽  
Higher Order ◽  
Higher Order Aberrations ◽  
Corneal Aberrations ◽  
Laser Technologies ◽  
Wavefront Measurement ◽  
Significant Difference ◽  
Profiler Plus ◽  
Higher Order Aberration

Introduction: Purpose of this study was to evaluate the inter-device agreement of ocular and corneal higher-order aberration measurements using various aberrometers. Materials and method: Ocular and corneal higher-order aberrations were measured from 57 eyes. For ocular aberration, the measurements were obtained from WASCA Analyzer (Carl Zeiss Meditec, Jena, Germany), i-Profiler Plus (Carl Zeiss Meditec, Jena, Germany) and OPD-Scan III (NIDEK Co. Ltd., Tokyo, Japan). Whereas for corneal aberration, an additional measurement was obtained from Atlas Corneal Topographer 9000 (Carl Zeiss Meditec, Jena, Germany). All the measurements were displayed by the Zernike algorithm. Root mean squares of total, 3rd and 4th order of higher-order aberrations were compared between any three devices using repeated measured analysis of variance. The Bland-Altman analysis and Pearson's correlation were employed to assess agreement and strength of relationship between measurements. Results: For ocular aberrations, there were no significant difference (P > 0.05) in all comparisons except for total higher-order aberration, oblique and horizontal trefoil. Whereas for corneal aberrations, vertical coma, spherical aberration and with-therule/against-the-rule secondary astigmatism between devices were found to be significantly different (P < 0.05). The most agreeable device pairs for ocular and corneal aberrations were demonstrated by i-Profiler Plus - OPD Scan III (95% limit of agreement: -0.340 to 0.730) and Atlas Corneal Topographer 9000 - i-Profiler Plus (limit of agreement: 0.196 to 0.520) respectively. The r-values are stronger than 0.70. Conclusion: There were differences in the value of higher-order aberrations between different aberrometry technologies. Clinical impact due to the differences in wavefront measurement between skiascopy, Placido-based and laser technologies need to be investigated further.

scholarly journals Effect of Corneal Refractive Surgery on Accommodative and Binocular Dysfunctions Among Civilian Pilots in Southwest China

2020 ◽  
Author(s):  
Ye Wu ◽  
Zhen Zhang ◽  
Meng Liao ◽  
Qi Li ◽  
XueLin Tang ◽  
...  
Keyword(s):  
Refractive Surgery ◽  
Southwest China ◽  
Specific Population ◽  
Visual Symptoms ◽  
Significant Difference ◽  
Refractive Status ◽  
Registration Number ◽  
Corneal Refractive Surgery ◽  
Age Range ◽  
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 range: 23-35 years) and 99 emmetropic civilian pilots (age range: 23-35 years) were included in this study. Visual symptoms, refractive status, accommodative and binocular tests of each subject were performed.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.Trial registration number: ChiCTR1900027235 (date: 6 Nov 2019) Available at www.medresman.org

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

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