Changes in Higher Order Aberrations after Wavefront-Guided Prk for Correction of Low to Moderate Myopia and Myopic Astigmatism: Two-Year Follow-Up

2007 ◽  
Vol 17 (4) ◽  
pp. 507-514 ◽  
Author(s):  
D. Wygledowska-Promienska ◽  
I. Zawojska

Purpose To assess efficacy, safety, and changes in higher order aberrations after wavefront-guided photorefractive keratectomy (PRK) in comparison with conventional PRK for low to moderate myopia with myopic astigmatism using a WASCA Workstation with the MEL 70 G-Scan excimer laser. Methods A total of 126 myopic or myopic-astigmatic eyes of 112 patients were included in this retrospective study. Patients were divided into two groups: Group 1, the study group; and Group 2, the control group. Group 1 consisted of 78 eyes treated with wavefront-guided PRK. Group 2 consisted of 48 eyes treated with spherocylindrical conventional PRK. Results Two years postoperatively, in Group 1, 5% of eyes achieved an uncorrected visual acuity (UCVA) of 0.05; 69% achieved a UCVA of 0.00; 18% of eyes experienced enhanced visual acuity of −0.18 and 8% of −0.30. In Group 2, 8% of eyes achieved a UCVA of 0.1; 25% achieved a UCVA of 0.05; and 67% achieved a UCVA of 0.00 according to logMAR calculation method. Total higher-order root-mean square increased by a factor 1.18 for Group 1 and 1.6 for Group 2. There was a significant increase of coma by a factor 1.74 in Group 2 and spherical aberration by a factor 2.09 in Group 1 and 3.56 in Group 2. Conclusions The data support the safety and effectiveness of the wavefront-guided PRK using a WASCA Workstation for correction of low to moderate refractive errors. This method reduced the number of higher order aberrations induced by excimer laser surgery and improved uncorrected and spectacle-corrected visual acuity when compared to conventional PRK.

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Banu Torun Acar ◽  
Suphi Acar

Purpose. To evaluate the effect of cap-lenticule diameter difference (CLDD) on the visual outcome and higher-order aberrations (HOAs) of small-incision lenticule extraction (SMILE). Methods. A total of 132 patients who had bilateral SMILE for myopia or myopic astigmatism were included. The CLDD was 0.4 mm in 54 patients (group 1) and 1.0 mm in 78 patients (group 2). The refractive parameters, uncorrected (UDVA) and corrected distance visual acuity (CDVA), and HOAs were determined preoperatively and during six months follow-up. Results. Group 1 had better CDVA (in logMAR) compared to group 2 at day 1 (−0.07 ± 0.07 versus 0.04 ± 0.07, resp.; p<0.001) and week 1 (−0.07 ± 0.07 versus –0.04 ± 0.07, resp.; p=0.001). The visual acuity improved more in group 1 than in group 2. The UDVA (in logMAR) was 0.07 ± 0.07 and 0.29 ± 0.09 at day 1 (p<0.001) and −0.08 ± 0.07 and −0.06 ± 0.06 at six months (p=0.038) in group 1 and group 2, respectively. Group 1 was associated with significantly less induction of HOAs (0.24 ± 0.08 μm and 0.32 ± 0.26 μm, resp.; p=0.002). Conclusions. In SMILE, 0.4 mm CLDD is associated with better visual outcome and less induction of HOAs than 1.0 mm. Narrow CLDD should be considered in SMILE to increase the visual acuity particularly in the early postoperative period.


2020 ◽  
Author(s):  
Lingyi Zhang ◽  
Meng Liao ◽  
Wenqiu Zhang ◽  
Longqian Liu

Abstract Background The study compared ocular higher-order aberrations (HOAs) between monocular anisometropic amblyopia children and similar anisometropia children with normal best-corrected visual acuity (BCVA). The amblyopia eyes could not reach the standard BCVA level of their age even after several months' regular treatment of amblyopia. We tried to find if these intractable amblyopia eyes have abnormal HOAs. Methods Fifty school-aged children (5–9 years) with hyperopic anisometropia were recruited at West China hospital clinic. Each subject shall be reexamined once every three months, four consecutive reexaminations for 12 months, of which only 25 subjects with normal BCVA after wearing glasses shall be included in the control group. The rest 25 subjects were treated by glasses and six months’ patching. Their interocular difference of visual acuity was still more than or equal to LogMAR 0.2, and the eyes with poor visual acuity did not reach the normal level in the twelfth month. These subjects were included in the amblyopia group. The BCVA, HOAs (5 mm pupil diameter), and axial length were recorded for all subjects. Results There were significant differences of higher order aberrations in C (3, -3) between the amblyopia eyes and the other three groups of eyes with normal BCVA (all p < 0.05). There were significant differences of higher-order aberrations in third-order root-mean-square aberrations(RMS) between the amblyopia eyes and the low-diopter eyes from two subject groups(both p < 0.05). Compared to high-diopter eyes in the control group, there were a significantly higher C(3,-3) in all amblyopia eyes and a significantly higher third-order RMS (p = 0.040) in the moderate-to-severe amblyopia group. In the Pearson correlation test, the C(3,-3) and third order RMS demonstrated statistically significant correlations with BCVA ( (r=-0.19, p = 0.04; r = 0.37, p < 0.01). Conclusions The anisometropic amblyopia eyes had different HOAs from the eyes with normal visual acuity. The third-order aberrations were the primary abnormal higher-order aberration in amblyopia eyes.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mohammad Miraftab ◽  
Hassan Hashemi ◽  
Mohammadreza Aghamirsalim ◽  
Shiva Fayyaz ◽  
Soheila Asgari

Abstract Background The refractive surgeries induce corneal higher order aberrations (C-HOAs). In this study, change of C-HOAs after small-incision lenticule extraction (SMILE) compared to femtosecond assisted laser in situ keratomileusis (femto-LASIK), and to photorefractive keratectomy with mitomycin-C (PRK) under photopic and mesopic conditions. Methods In this prospective study, age, gender, and apical corneal thickness (ACT) matched cases with moderate myopia [spherical equivalent (SE) 3.00 to 6.00D) to high myopia (SE > 6.00D)] were enrolled. In addition to visual acuity and refraction, total C-HOA, coma, spherical aberration (SA), and trefoil in the 3- and 6-mm zones were measured before and 3 and 6 months after surgery. Results Overall, 372 moderate myopia cases (124 eyes of 124 individuals in each surgical group) and 171 high myopia cases (57 eyes of 57 individuals in each surgical group) were enrolled. At baseline, the differences in age, gender, ACT, uncorrected and corrected visual acuity, and SE were not statistically significant between subgroups of surgical methods within each myopia group (all P > 0.05). At 12 months, in the moderate myopia group, there was less increase in 6-mm zone total C-HOA, coma, and SA with SMILE compared to the other groups (all P < 0.05). In the high myopia group, there was greater increase in photopic total C-HOA and trefoil and less increase in mesopic SA with SMILE (all P < 0.05). Conclusions In correction of moderate myopia, SMILE has better results in mesopic condition. In high myopia correction, femto-LASIK and PRK have better results in photopic and SMILE in mesopic condition.


2019 ◽  
Vol 30 (5) ◽  
pp. 978-984
Author(s):  
Meryem Altin Ekin ◽  
Seyda Karadeniz Ugurlu

Objective: To evaluate the changes of visual acuity, contrast sensitivity, astigmatism, and higher order aberrations after blepharoplasty in patients with dermatochalasis. Methods: Two hundred six eyelids of 103 patients with dermatochalasis were prospectively studied. Visual acuity, contrast sensitivity, corneal topography, astigmatism degree, and higher order aberrations were examined and recorded before and at 1 month after upper eyelid blepharoplasty. Change in contrast sensitivity and astigmatism values were determined according to margin reflex distance of patients, which were classified into three following groups: <2 mm, 2–3 mm, and ⩾ 4 mm. A Wilcoxon signed rank test was performed to compare the difference. Results: No significant differences were observed for visual acuity (p = 0.157). The contrast sensitivity of patients significantly increased at all spatial frequencies both under glare and nonglare conditions (p < 0.05). The mean refractive astigmatism significantly decreased from ‒1.01 ± 1.3 to ‒0.79 ± 0.71, postoperatively (p = 0.029). In patients with marginal reflex distance < 2 mm, mean contrast sensitivity was increased (p < 0.001) and mean astigmatism was decreased significantly (p < 0.001) compared with those with ⩾ 2 mm. Higher order aberrations decreased significantly from 0.62 ± 0.41 µm to 0.55 ± 0.38 µm (p = 0.038) after blepharoplasty. Root mean square of the vertical trefoil (p = 0.038), vertical coma (p = 0.002), horizontal trefoil (p = 0.027), third-order aberration (p = 0.005), secondary vertical stigmatism (p = 0.001), spherical aberration (p = 0.023), secondary horizontal astigmatism (p = 0.002), fourth-order aberration (p = 0.024), vertical pentafoil (p = 0.015), secondary horizontal coma (p = 0.035), secondary horizontal trefoil (p = 0.030), and horizontal pentafoil (p = 0.048) were decreased significantly. Conclusion: Upper eyelid blepharoplasty in patients with dermatochalasis has a significant improvement in visual function in terms of contrast sensitivity, astigmatism, and higher order aberrations.


Author(s):  
Omar Khaled Yaseer, Taym Darwish, Najwa Kurdogly Omar Khaled Yaseer, Taym Darwish, Najwa Kurdogly

Purpose: The aim of this study is to evaluate the root mean square error (RMS) of corneal higher- order aberrations in Syrian adult population in different refractive status (emmetropia, myopia, hyperopia and simple myopic astigmatism). Methods: This cross- sectional study was conducted at Tishreen University Hospital in Latakia, Syrian Arab Republic. A total of 420 patients (840 eyes), ages 18- 40 years, participated in the study. Refraction was measured with an autorefractor keratometer and expressed as a spherical equivalent. Total corneal higher- order aberrations (Coma, Spherical Aberration, Trefoil) were measured using Sirius Corneal Topography at a pupil diameter of 5 mm. Results: RMS of Coma and Spherical aberrations peaked in the hyperopia group (0.18 ± 0.08, 0.11 ± 0.02) respectively. Whereas, Trefoil was higher in the severe myopia and simple myopic astigmatism groups (0.25 ± 0.05, 0.25 ± 0.08) respectively. Conclusions: Among a Syrian population, some types of refractive status were associated with certain types of higher- order aberrations, with a significant increase in trefoil in severe myopia and simple myopic astigmatism.


2020 ◽  
Vol 17 (4) ◽  
pp. 719-724
Author(s):  
E. P. Tarutta ◽  
N. V. Khodzhabekyan ◽  
A. T. Khandzhyan ◽  
M. D. Sengaeva ◽  
S. D. Harutunyan ◽  
...  

Purpose. Comparative analysis of the wavefront aberrations and ophthalmoergonomic parameters after excimer laser and orthokeratological correction of myopia in patients aged over 35 years.Patients and methods. The study included 21 patients: 12 (24 eyes) after excimer laser correction of myopia (group 1) and 9 (18 eyes) after orthokeratology (group 2). The average age of patients after excimer laser surgery was 38.5 years, after orthokeratological correction 46.1 years. Special studies included ophthalmoergonomical tests: far and near distance visual acuity, capacity of the visual analyzer, visual productivity, reading velocity, mesopic vision, relative accommodation reserves, objective accommodative response, pseudo-accommodation volume. Wavefront aberrations were conducted on the OPD-scan 3.Results. The spherical equivalent of residual refraction was –0.625 ± 0.08D in the excimer group, and –1.58 ± 0.24D in orthokeratological group. Despite the difference in refraction, values of distance binocular and monocular visual acuity were the same in both groups: in group 1 monocular visual acuity was 0.74 ± 0.03, binocular 0.85 ± 0.03; in group 2 — 0.71 ± 0.06 and 0.89 ± 0.05 respectively. The parameters of both monocular and binocular accommodative response measured on Grand Seiko were 50 % higher in the excimer group compared to those in the orthokeratological group. Relative accommodation reserves appeared to be two times more in the excimer group. The volume of pseudo-accommodation was 2.375 ± 0.12D in group 1, which appeared to be 20 % more than in the group 2 (p = 0.0414). The level of wavefront aberrations was significantly higher in orthokeratological group with the exception of vertical aberrations and, especially horizontal coma, which were significantly higher after excimer laser surgery. Generally, the dynamics of aberrations in both groups correlates with changes of the corneal topography.Conclusion. Excimer laser surgery with hypocorrection is more recommended for patients aged 35–40, and orthokeratological correction for patients over 45 years old. 


2018 ◽  
Vol 12 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Smita Agarwal ◽  
Erin Thornell ◽  
Chris Hodge ◽  
Gerard Sutton ◽  
Paul Hughes

Background: Laser-Assisted in situ Keratomileusis (LASIK) can induce corneal aberrations that can impact vision and patient satisfaction. Recent developments in laser technologies have helped minimise these aberrations. Objective: To assess the quality of vision and change in Higher-Order Aberrations (HOAs) following wavefront-optimized LASIK in low-myopic astigmatic patients. Methods: LASIK was performed on a total of 76 eyes in patients with myopia <4.0 D and cylinder <2.0 D using the WaveLight® EX500 excimer and FS200 femtosecond laser platform. Visual acuity, contrast sensitivity and HOAs were measured at 1 and 3 months postoperatively and compared to preoperative values. Subjective quality of vision was assessed pre- and postoperatively using a VF14 questionnaire. Results: Mean postoperative Spherical Equivalent (SE) was -0.09 ± 0.26 µm with 95% of patients within ± 0.5 D of attempted SE. Postoperative uncorrected distance visual acuity was 20/20 or better for 96% of patients. Contrast sensitivity increased against horizontal and vertical gratings at all spatial frequencies except for vertical gratings at 18 cycles/degree. Spherical aberration and total HOA increased by 0.085 µm and 0.13 µm respectively. The mean VF14 score increased from 89.2 ± 16.7% to 99 ± 1.4% postoperatively. Conclusion: LASIK performed using the WaveLight® EX500 excimer and WaveLight® FS200 laser platform provided improved contrast sensitivity and visual acuity with minimal introduction of HOAs, making it a suitable platform for low myopic astigmatic patients.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Santiago Delgado-Tirado ◽  
Alberto López-Miguel ◽  
Yazmin Báez-Peralta ◽  
Lucía González-Buendía ◽  
Itziar Fernández ◽  
...  

Abstract Background Prevalence of high myopia is continuously increasing, thus, patients affected with staphyloma are abundant worldwide. Assessment of the quality of vision in these patients is mandatory for a proper clinical counselling, specially when undergoing surgical procedures that require intraocular lenses implantation. Thus, the purpose of the study was to assess monochromatic higher order aberrations (HOAs) in highly myopic eyes with staphyloma with or without a dome-shaped macula. Methods Participants underwent spectral-domain optical coherence tomography, ocular axial biometry, dual Scheimpflug photography and integrated Placido disk topography, and Hartmann-Shack wavefront analysis. Five groups were evaluated: a low-moderate myopia control group (< 6.00 diopters, n = 31) and four high myopia (≥6.00 diopters) groups: eyes without staphyloma (n = 18), eyes with inferior staphyloma (n = 14), eyes with posterior staphyloma without dome-shaped macula (n = 15) and eyes with posterior staphyloma with dome-shaped macula (n = 17). Subsequently, two new groups (including all participants) were created to assess differences between myopia with and without staphyloma. One-way analysis of covariance was performed using age and lens densitometry as covariates. Results Statistically significant (p ≤ 0.05) differences in anterior corneal fourth-order HOAs were observed between the low-moderate myopia and no-dome-shaped macula (Mean: 0.16 μm) and dome-shaped macula posterior staphyloma groups (Mean: 0.12 μm) in younger patients (≤45 years old). The same groups also showed (p ≤ 0.05) significant differences for anterior corneal primary spherical aberration (Mean: 0.19 and 0.13 μm, respectively). In addition, anterior corneal tetrafoil was significantly higher (p = 0.04) in dome-shaped macula compared to no-dome-shaped macula (Mean: 0.18 vs 0.06 μm, respectively). When all participants were grouped together, significantly lower mean anterior corneal primary spherical aberration (0.15 μm vs. 0.27 μm, p = 0.004) and higher internal primary spherical aberration (0.04 μm vs. -0.06 μm, p = 0.04) was observed in staphyloma compared to no-staphyloma myopic patients. Conclusions Eyes with high myopia and staphyloma have less positive anterior corneal primary spherical aberration and less negative internal primary spherical aberration, suggesting that the anterior corneal surface tends to mimic in a specular fashion the posterior pole profile. This corneal behaviour appears to change in patients older than 45 years.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yuan Wu ◽  
Shuhan Wang ◽  
Guiqin Wang ◽  
Shaozhen Zhao ◽  
Ruihua Wei ◽  
...  

Objective. To compare the corneal asphericity and higher-order aberrations (HOAs) of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) with Smart Pulse Technology (SPT) assisted transepithelial photorefractive keratectomy (Trans-PRK) for myopia and myopic astigmatism correction. Methods. This prospective study analyzed 88 eyes of 44 patients treated with FS-LASIK and 64 eyes of 32 patients treated with Trans-PRK. All eyes had low to moderate myopia with or without astigmatism (spherical equivalent (SE) <−6.00 diopters). The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), SE, asphericity (Q value) of the anterior corneal surface, index of surface variance (ISV), corneal higher-order aberrations (HOAs), vertical coma (Z3−1), horizontal coma (Z31), and spherical aberration (Z40) over a 6 mm diameter central corneal zone diameter were evaluated preoperatively and 1, 3, and 6 months postoperatively. Results. At 6 months, the UDVA and SE were −0.14 ± 0.06 and 0.33 ± 0.33D in FS-LASIK and −0.15 ± 0.06 and 0.35 ± 0.37D in Trans-PRK. There was no difference between the two groups in the postoperative UDVA and SE ( P > 0.05 ). After FS-LASIK and Trans-PRK, the Q values in the 6, 7, 8, and 9 mm zones and ISV of the anterior corneal surface significantly increased ( P < 0.001 ). At 1, 3, and 6 months after surgery, corneal HOA, Z3-1, Z31, and Z40 in both groups were significantly increased compared with those before surgery, with statistically significant differences ( P < 0.001 ). At 1, 3, and 6 months after surgery, the Z3−1 of the Trans-PRK group was significantly lower than that of the FS-LASIK group ( P < 0.001 ). ΔHOA and ΔZ40 were dramatically correlated with the ΔQ value for both FS-LASIK and Trans-PRK procedures. The ΔQ was significantly correlated with the preoperative SE, AD, and AD/CCT after both two procedures (all P < 0.001 ). Conclusions. Both FS-LASIK and Trans-PRK caused the anterior corneal surface to become flatter, and the morphology of the corneal surface was irregular. Corneal HOAs were significantly increased after the two procedures. Trans-PRK using SPT introduced less corneal vertical coma than FS-LASIK. Corneal asphericity changes contributed to the corneal aberrations changes following FS-LASIK and Trans-PRK.


2021 ◽  
Author(s):  
Mohammad Miraftab ◽  
Hassan Hashemi ◽  
Mohammadreza Aghamirsalim ◽  
Shiva Fayyaz ◽  
Soheila Asgari

Abstract Background The refractive surgeries induce corneal higher order aberrations (C-HOAs). In this study, change of C-HOAs after small-incision lenticule extraction (SMILE) compared to femtosecond assisted laser in situ keratomileusis (femto-LASIK), and to photorefractive keratectomy with mitomycin-C (PRK) under photopic and mesopic conditions. Methods In this prospective study, age, gender, and apical corneal thickness (ACT) matched cases with moderate myopia [spherical equivalent (SE) 3.00 to 6.00D) to high myopia (SE > 6.00D)] were enrolled. In addition to visual acuity and refraction, total C-HOA, coma, spherical aberration (SA), and trefoil in the 3- and 6-mm zones were measured before and 3 and 6 months after surgery. Results Overall, 372 moderate myopia cases (124 eyes of 124 individuals in each surgical group) and 171 high myopia cases (57 eyes of 57 individuals in each surgical group) were enrolled. At baseline, the differences in age, gender, ACT, uncorrected and corrected visual acuity, and SE were not statistically significant between subgroups of surgical methods within each myopia group (all P > 0.05). At 12 months, in the moderate myopia group, there was less increase in 6-mm zone total C-HOA, coma, and SA with SMILE compared to the other groups (all P < 0.05). In the high myopia group, there was greater increase in photopic total C-HOA and trefoil and less increase in mesopic SA with SMILE (all P < 0.05). Conclusion In correction of moderate myopia, SMILE is preferable to prevent dilated pupil visual problems. In high myopia correction, femto-LASIK and PRK is preferred for normal light activities and SMILE is recommended to avoid dilated pupil visual problems.


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