Aspherical iols and their effect on visual acuity, depth of field, spherical aberration and contrast sensitivity

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.

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Effect of partial and full correction of corneal spherical aberration on visual acuity and contrast sensitivity

Journal of Cataract & Refractive Surgery ◽

10.1016/j.jcrs.2008.12.041 ◽

2009 ◽

Vol 35 (5) ◽

pp. 949-951 ◽

Cited By ~ 7

Author(s):

Teresa Ferrer-Blasco

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Spherical Aberration ◽

Full Correction

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The Topographical Effect of Optical Zone Diameter in Orthokeratology Contact Lenses in High Myopes

Journal of Ophthalmology ◽

10.1155/2019/1082472 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

G. Carracedo ◽

T. M. Espinosa-Vidal ◽

I. Martínez-Alberquilla ◽

L. Batres

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Contact Lenses ◽

Spherical Aberration ◽

Ring Width ◽

Treatment Area ◽

Low Contrast ◽

Zone Diameter ◽

Peripheral Ring ◽

Optical Zone

Purpose. To evaluate the effect of the optical zone diameter (OZ) in orthokeratology contact lenses regarding the topographical profile in patients with high myopia (−4.00 D to −7.00 D) and to study its effect over the visual quality. Materials and Methods. Twelve patients (18 eyes) were fitted with overnight orthokeratology (OrthoK) with a randomized 6 mm or 5 mm OZ lens worn for 2 weeks, followed by a 2-week washout period, between both designs. Keratometry (K) readings, optical zone treatment diameter (OZT), peripheral ring width (PRW), higher-order aberrations (HOA), high (HC) and low contrast (LC) visual acuity, and subjective vision and comfort were measured at baseline and after 2 weeks of OrthoK lens wear of each contact lens. Results. No significant differences were found between any measurements for the same subject at both baselines (p value > 0.05). There was no difference between OZ lens designs found in refraction, subjective vision or comfort, and HC and LC visual acuity. Contrast sensitivity was decreased in the 5 mm OZ lens design compared with 6 mm OZ design (p-value < 0.05). 5 mm OZ design provoked a greater flattening, more powerful midperipheral ring and 4th-order corneal and total spherical aberration than the 6 mm OZ design, being statistically significant after 7 days, for corneal aberration, and 15 days, for corneal and total, of wearing the lens (p-value < 0.05). The OZT obtained were 2.8 ± 0.2 mm and 3.1 ± 0.1 mm for 5 mm and 6 mm OZ design, respectively (p-value < 0.05). Regarding PRW, the 5 mm OZ design had a wider ring width in both the nasal and temporal zones (p-value < 0.05). Conclusions. A smaller diameter optical zone (5 mm) in orthokeratology lenses produces a smaller treatment area and a larger and more powerful midperipheral ring, increasing the 4th-order spherical aberration that affects only the contrast sensitivity but without differences in visual acuity and subjective vision compared with a larger OZ diameter (6 mm).

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Visual Function and Subjective Quality of Life in Chinese Cataract Patients after Implantation with Aspheric Intraocular Lenses

European Journal of Ophthalmology ◽

10.5301/ejo.2011.6441 ◽

2011 ◽

Vol 21 (6) ◽

pp. 732-740

Author(s):

Yanwen Fang ◽

Yi Lu ◽

Xinhua Wu ◽

Aizhu Miao ◽

Yi Luo

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Visual Function ◽

Spherical Aberration ◽

Visual Quality ◽

Intraocular Lenses ◽

Subjective Quality Of Life ◽

Significant Difference ◽

The Mean ◽

Cataract Patients

Purpose. To evaluate and compare the objective and subjective visual function after implantation of 2 aspheric intraocular lenses (IOLs) in Chinese cataract patients. Methods. Forty-one eyes of 28 patients with cataract were randomly assigned to receive either the MC X11 ASP IOL or the AcrySof IQ IOL. Three months postoperatively, best-corrected visual acuity (BCVA), contrast sensitivity, wavefront aberrations, and subjective visual quality were measured. The degree of posterior capsule opacification (PCO) was recorded at last follow-up. Results. Postoperative mean monocular BCVA was 0.05±0.13 logMAR in the MC X11 group and 0.05±0.08 logMAR in the IQ group. There was no significant difference in visual acuity, contrast sensitivity, subjective visual quality, and degree of PCO between the 2 groups. For a 6-mm pupil diameter, the mean spherical aberration (Z40) was 0.075±0.076 μm in the MC X11 group and 0.056±0.111 μm in the IQ group. However, 45.5% and 57.9% of the eyes in the MC X11 and IQ groups had values >0.10 μm, respectively. The mean RMS values of the high-order aberrations were similar between the 2 groups except the higher fifth- and sixth-order aberrations, which were significantly higher in the MC X11 group. Conclusions. Both IOLs provided similar and good visual outcomes. However, the data suggest that the amount of negative spherical aberration generated by current available aspheric IOLs might not be optimal for Chinese eyes.

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Visual Outcomes and Higher Order Aberrations Following LASIK on Eyes with Low Myopia and Astigmatism

The Open Ophthalmology Journal ◽

10.2174/1874364101812010084 ◽

2018 ◽

Vol 12 (1) ◽

pp. 84-93 ◽

Cited By ~ 8

Author(s):

Smita Agarwal ◽

Erin Thornell ◽

Chris Hodge ◽

Gerard Sutton ◽

Paul Hughes

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Spherical Aberration ◽

Higher Order ◽

Higher Order Aberrations ◽

Corneal Aberrations ◽

Spatial Frequencies ◽

Quality Of Vision ◽

Recent Developments

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.

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Corneal Cap Thickness and Its Effect on Visual Acuity and Corneal Biomechanics in Eyes Undergoing Small Incision Lenticule Extraction

Journal of Ophthalmology ◽

10.1155/2018/6040873 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Ting Liu ◽

Ting Yu ◽

Lina Liu ◽

Kaijian Chen ◽

Ji Bai

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Spherical Aberration ◽

Corneal Thickness ◽

Cutoff Frequency ◽

Corneal Biomechanics ◽

Controlled Study ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction

Purpose. To evaluate the effect of corneal cap thickness on visual acuity and corneal biomechanics in small incision lenticule extraction (SMILE) for the treatment of myopia. Methods. Forty eyes of 20 patients undergoing SMILE for the treatment of myopia were enrolled in this prospective controlled study. The patients with 510 μm–560 μm central corneal thickness (CCT) and a refractive spherical equivalent of −3.00 D to −8.00 D were included. It was designed randomly to undergo SMILE with a 110 μm cap thickness in one eye and 150 μm cap thickness in the other. Ophthalmic examinations included best-corrected and uncorrected visual acuity (UCVA); refractive status, contrast sensitivity, and objective visual quality were evaluated at 2 h, 4 h, and 24 h postoperatively; while at 3 months after the procedure, corrected intraocular pressure (IOP), higher order aberrations (HOAs), and morphologic modifications of corneal architecture of both eyes were assessed. Results. Compared with the 150 μm group, the incidence of OBL was significantly higher in the 110 μm cap thickness group (P=0.004), and UCVA, Strehl ratio (SR), objective scatter index (OSI), modulation transfer function (MTF) cutoff frequency, and photopic and scotopic contrast sensitivity at medium spatial frequency were all significantly better in 110 μm group at 2 h and 24 h postoperatively (P<0.05). Corneal spherical aberration and corrected IOP by Corvis ST were significantly higher in the 110 μm group at 3 months postoperatively (P<0.05). No statistically significant differences were found in manifest refraction, UCVA, SR, OSI, MTF cutoff, and mesopic and photopic contrast sensitivity at low frequency, photopic contrast sensitivity at high frequency, endothelial density, corneal coma, and total HOAs at 3 months after the procedure. No visual decline was found in the patients in this study. Conclusions. Both 110 μm and 150 μm cap thickness in SMILE were safe and effective for treatment of myopia. A 110 μm cap thickness demonstrated better visual outcomes during early and late postoperative periods with higher corneal spherical aberration and corrected IOP at 3 months postoperatively. This trial is registered with ChiCTR-IOR-17013369.

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Lack of Effect of Intraocular Lens Asphericity on Visual Performance with Acrylic Intraocular Lenses

European Journal of Ophthalmology ◽

10.5301/ejo.2011.6356 ◽

2011 ◽

Vol 21 (6) ◽

pp. 723-731 ◽

Cited By ~ 4

Author(s):

Gonzalo Muñoz ◽

César Albarrán-Diego ◽

Ma Ángeles Galotto ◽

Javier Pascual ◽

Teresa Ferrer-Blasco

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Intraocular Lens ◽

Spherical Aberration ◽

Optical Quality ◽

Intraocular Lenses ◽

Bilateral Cataract ◽

Quality Of Vision ◽

Ocular Aberrations

Purpose. To determine whether implantation of acrylic intraocular lens (IOL) with aspheric design (Tecnis Z9003, AMO) results in improved visual acuity or contrast sensitivity compared with conventional spherical acrylic IOL (AR40e, AMO). Methods. In an intraindividual randomized prospective study of 60 patients with bilateral cataract, the Tecnis Z9003 IOL was compared with the AR40e IOL. Ocular aberrations for a 4.0-mm pupil and 6.0-mm pupil were measured with a Hartmann-Shack aberrometer. Quality of vision was measured using visual acuity and contrast sensitivity under mesopic and photopic conditions. Results. Eyes with the Tecnis Z9003 IOL had significantly less spherical aberration and greater Strehl ratio after surgery, showing a better optical quality in comparison with the standard spherical IOL. However, visual acuity and both mesopic and photopic contrast sensitivity were not significantly different between the groups. Conclusions. The significantly better optical quality achieved with the aspheric acrylic IOL design did not result in improved visual acuity or contrast sensitivity in comparison with a conventional spherical acrylic IOL.

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Peripheral Refraction, Wave Front of the Eye and Visual Performance in the Correction of Myopia in Children with Bifocal Soft Contact Lenses with High Addition

Ophthalmology in Russia ◽

10.18008/1816-5095-2021-3-518-526 ◽

2021 ◽

Vol 18 (3) ◽

pp. 518-526

Author(s):

E. P. Tarutta ◽

S. V. Milash ◽

M. V. Epishina

Keyword(s):

Visual Acuity ◽

Contrast Sensitivity ◽

Contact Lenses ◽

Spherical Aberration ◽

Sharp Decrease ◽

Soft Contact ◽

Wavefront Aberrations ◽

Soft Contact Lenses ◽

Soft Contact Lens

Purpose: to study the effect of bifocal soft contact lens (BSCL) with an ADD of 4 diopters on peripheral refraction (PR), optical and ergonomic eye parameters in children with myopia.Patients and methods. 26 patients (52 eyes) with myopia –3.09 ± 1.13 diopters at the age of 10.04 ± 1.5 years without correction and with correction by BSCL Prima BIO Bi-focal ( Okay Vision Retail, Russia). All patients underwent a horizontal and vertical PR study on an open field autorefractometer Grand Seiko WAM-5500 (Japan), wavefront aberrations were studied on OPD-Scan III aberrometer (Nidek, Japan), contrast sensitivity under mesopic conditions were studied on a Mesotest 2 instrument (Oculus, Germany) and visual productivity was studied using test tables.Results. The visual acuity of the distance with a BSCL correction of 0.98 ± 0.04 did not differ (p = 0.26) from the maximum visual acuity corrected by spherocylindrical glasses of 0.99 ± 0.04. BSCL induces myopic defocus in all peripheral zones, with a maximum value of 15° and a sharp decrease of 30°. Peripheral myopic defocus induced by the lens at a horizontal and vertical angle of 15 degrees did not depend on the initial degree of myopia. BSCL increases the total RMS from 0.07 ± 0.02 μm to 0.19 ± 0.07 μm in the 3 mm zone (p < 0.01) and from 0.27 ± 0.09 μm to 1.18 ± 0, 23 μm in the 6 mm zone (p < 0.01), mainly due to an increase in spherical aberration from –0.0005 ± 0.006 μm to 0.06 ± 0.01 μm (p < 0.01) and from 0.01 ± 0.09 μm to 0.58 ± 0.14 μm (p < 0.01) in the 3 mm and 6 mm zones, respectively. An increase in the overall RMS in BSCL reduces the quality of eye optics and contrast sensitivity under mesopic conditions, but does not impair visual productivity.Conclusion. BSCLs with a high ADD of 4 diopters are capable of inducing significant myopic peripheral defocus due to the induction of spherical aberration, while maintaining high visual acuity and not changing ophthalmic ergonomics, which makes them a pathogenetically substantiated method for correcting myopia and preventing its progression in children and adolescents.

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