scholarly journals Stereoscopic Vision and Testing Techniques – Review

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Diagnostic Tests ◽  
Early Years ◽  
Stereoscopic Vision ◽  
Risk Of Injury ◽  
Field Of Vision ◽  
Quality Of Vision ◽  
Testing Techniques

Stereoscopic vision or stereopsis is the highest level of binocular vision. It is acquired in the early years of life and requires the “simultaneous perception” of each eye separately, as well as the “matching” of the two images during brain development. First of all, it gives man the visual perception of depth, but it also broadens his field of vision and increases his visual acuity. As anyone can easily understand it is especially useful in everyday life. It is not particularly well known, but the quality of vision at night is based on stereotypes. Finally, people who do not have stereoscopic vision are in a difficult position as they are at immediate risk of injury. For the above reasons, it is clear why constipation should be controlled, with specific diagnostic tests, especially during childhood.

scholarly journals Objective and subjective evaluation of trifocal diffractive intraocular Lens after cataract extraction with phacoemulsification: a prospective clinical study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ahmed A. Zein El-Dein ◽  
Ahmed Elmassry ◽  
Hazem M. El-Hennawi ◽  
Ehab F. Mossallam
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Intraocular Lens ◽  
Subjective Evaluation ◽  
Cataract Extraction ◽  
Prospective Clinical Study ◽  
Gradual Change ◽  
Quality Of Vision ◽  
Defocus Curve

Abstract Background This study aimed to assess visual outcomes, quality of vision and patients’ satisfaction of a trifocal diffractive intraocular lens after cataract surgery with phacoemulsification. Results The study included 36 eyes that underwent implantation of trifocal diffractive intraocular lens (IOL). The residual mean postoperative spherical equivalent was − 0.40 ± 0.29 diopters. Mean Uncorrected distance visual acuity was 0.80 ± 0.16 decimal (snellen equivalent 25 ft) while mean Uncorrected intermediate visual acuity was 0.82 ± 0.31 decimal (snellen equivalent 25 ft) and mean Uncorrected near visual acuity (UCNVA) was 0.87 ± 0.20 decimal (snellen equivalent 23 ft). In defocus curve, there was infinitesimal gradual change between the three foci. Contrast sensitivity was just below the inferior limit of normal. Conclusion Trifocal diffractive IOL created a true intermediate focus proved by VA and defocus curve and better quality of vision assessed by contrast sensitivity and high order aberration. Moreover, it was safe and effective for correcting distance and near vision in these patients. Most of the patients were very satisfied and achieved spectacle independence. Trial registration Registration number and date: NCT04465279 on July 10, 2020.

Keratoconic Bi-aspheric Contact Lenses

2016 ◽  
Vol 5 (3) ◽  
pp. 132-138
Author(s):  
Ariela Gordon-Shaag ◽  
Philip Fine ◽  
Liat Gantz ◽  
Arige Gideon-Abousaid ◽  
Gad Serero
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Case Series ◽  
Visual Stability ◽  
Wavefront Aberrations ◽  
Body Sensation ◽  
Quality Of Vision ◽  
Base Curve ◽  
Aspheric Lenses

ABSTRACT Aim This observational clinical case series examined patients with keratoconus (KC) fit with keratoconic bi-aspheric (KBA) lenses to assess visual acuity (VA), wavefront aberrations, physiological fitting, subjective comfort, and manufacturer's fitting guidelines. Materials and methods Seven adult patients (11 eyes, four females, mean age: 34.15 ± 14.12) with nipple cones from the Hadassah Academic College contact lens clinic (Jerusalem, Israel) were fit with KBA lenses by modifying the initial base curve (BC) to obtain an acceptable physiological fit. The uncorrected and corrected distance (D) and near (N) Snellen VA and the ocular wavefront measurements, and responses to a self-administered five-point scale questionnaire were compared after 2 weeks of wear using paired two-tailed t-test or Mann-Whitney U test, as appropriate. Results Visual acuity and total root mean square (RMS) improved significantly with the lenses (DVAuncorrected = 0.04 ± 0.02, DVAcorrected = 0.66 ± 0. 22, NVAuncorrected = 0.34 ± 0.30, NVAcorrected = 0.95 ± 0.12). Subjects reported an average of 7.0 ± 2.7 hours of wear daily, with good scores in visual stability, satisfaction with VA and quality of vision, improvement of mood and quality of life, and low scores in foreign body sensation, pain, red eye, and itching during wear, and difficulty with lens removal. An average of two BC modifications from the diagnostic lens were necessary (0.16 mm steeper in nine eyes, 0.27 mm flatter in two eyes). Conclusion Keratoconic bi-aspheric lenses can provide 7 hours of comfortable wear, significantly improved VA and total RMS aberrations, alongside subjective satisfaction. Base curve modifications can be reduced by fitting a diagnostic lens 0.75 mm steeper than the flattest keratometry reading. How to cite this article Gantz L, Gordon-Shaag A, Gideon-Abousaid A, Serero G, Fine P. Keratoconic Bi-aspheric Contact Lenses. Int J Kerat Ect Cor Dis 2016;5(3):132-138.

scholarly journals Visual Performance of Tecnis ZM900 Diffractive Multifocal IOL after 2500 Implants: A 3-Year Followup

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Leonardo Akaishi ◽  
Rodrigo Vaz ◽  
Graziela Vilella ◽  
Rodrigo C. Garcez ◽  
Patrick F. Tzelikis
Keyword(s):  
Visual Acuity ◽  
Visual Performance ◽  
Iol Implantation ◽  
Multifocal Iol ◽  
Uncorrected Distance Visual Acuity ◽  
Quality Of Vision ◽  
Near Visual Acuity ◽  
Minimum Followup ◽  
Second Procedure

Purpose. To evaluate visual performance for near, intermediate, and distant vision; complaints of photic phenomena, and patient satisfaction with the new diffractive multifocal IOL used in eyes which underwent phacoemulsification.Methods. Two thousand and five hundred consecutive eyes undergoing Tecnis ZM900 multifocal IOL implantation were included in this retrospective analysis. The minimum followup of 3 months was required after the surgery. Patients were assessed for uncorrected near visual acuity (UNVA) at a fixed distance (33 cm), uncorrected intermediate visual acuity (UIVA) at 60 cm, and uncorrected distance visual acuity (UDVA). Using a subjective questionnaire, patients satisfaction, their independence from using glasses, and the perception of glare and halo phenomena were also evaluated at the last follow-up.Results. Two thousand and five hundred eyes of 1558 patients underwent cataract surgery and Tecnis ZM900 multifocal IOL implantation. Four hundred and eighty seven patients (31.3%) were men, and 1071 (68.7%) were women. The mean age of the patients was 66.17 years. A UDVA of 20/30 or better was achieved by 85% of eyes. A UNVA of J1 was achieved by 93.7% of eyes and that of J2 or better was achieved by 98%. A UIVA of J4 or better was achieved by 65% and J5 or better was achived by more than 82.8% of the eyes in the study. Glare and halos were reported as severe by only 6.1% and 2.12% of patients, respectively. Ninety seven percent reported complete spectacle independence and 88% stated that they are totally satisfied with their quality of vision and would choose to have the same lens implanted again after the first implant. Five percent of the eyes in the study needed a second procedure (enhancement) to achieve a better visual result. No patient underwent lens exchange.Conclusion. Excellent near, intermediate, and distant vision was observed in patients implanted with the Tecnis ZM900 diffractive multifocal IOL. Spectacle independence and a minimum occurrence of photic phenomena make this IOL an excellent option in patients with cataract.

scholarly journals Quality of Vision Following LASIK and PRK-MMC for Treatment of Myopia

2021 ◽  
Author(s):  
Hong Gao ◽  
Tyler P Miles ◽  
Ray Troche ◽  
Donna M Murdoch ◽  
Vilhelm F Koefoed ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Repeated Measures ◽  
Military Service ◽  
High Order ◽  
Mean Difference ◽  
Analysis Of Covariance ◽  
Prospective Clinical Study ◽  
Quality Of Vision ◽  
High Order Aberrations

ABSTRACT Introduction Femtosecond-assisted thin flap, laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy with mitomycin-C (PRK-MMC) are the two most common refractive surgical procedures used to enhance visual capability in the U.S military. The purposes of the study were to examine effects on quality of vision following LASIK and PRK-MMC using a novel computer-based quick contrast sensitivity function (qCSF) test. Materials and Methods This prospective clinical study included 58 active duty U.S. military service members who elected LASIK (n = 29) or PRK-MMC (n = 29) refractive surgery for myopia (nearsightedness) treatment. Monocular photopic and mesopic quality of vision of the right eyes in spectacle correction preoperatively and unaided right eyes at four postoperative follow-up visits (1 week, 2 weeks, 1 month, and 3 months) were examined using the qCSF device. Two qCSF parameters, area under a log CSF (AULCSF) between 1.5 and 18 cycles per degree, and CSF cutoff acuity (CSF Acuity), were collected using a 50-trial setting at a 4-m testing distance. General linear model (GLM) Repeated-measures Analysis of Covariance was used to examine effects on quality of vision following LASIK and PRK-MMC. Post hoc testing with Bonferroni correction was used for pairwise comparisons, and preoperative cylinder refraction was used as a covariate. Two-tailed independent t-test was used to compare preoperative and postoperative parameters between LASIK and PRK-MMC. Pearson’s correlation, Bland–Altman plots, and multiple linear regression were used to examine the relationship among the qCSF and other vision tests. Results Quality of vision, AULCSF, and CSF Acuity returned to the preoperative baseline at postoperative 2 weeks under mesopic condition and at postoperative 1 month under photopic condition after PRK-MMC. In comparison, photopic and mesopic quality of vision were not significantly different from the baseline at any of the four postoperative visits following LASIK. Changes of CSF Acuity from the baseline after LASIK were significantly better under photopic than mesopic condition by 0.067 ± 0.014 logarithm of the minimum angle of resolution (logMAR); P < .001). Quality of vision was not significantly different between the LASIK and PRK-MMC groups at postoperative 1 and 3 months. When predicting photopic AULCSF (overall model fit R2 = 0.47), 5% contrast acuity (beta = −0.43), visual acuity in 100% contrast (beta = −0.18), and residual refraction in spherical equivalent (beta = 0.20) were significant predictors (P ≤ .001), while high-order aberrations (beta = −0.07, P = .22) were not significant predictors. Visual acuity (beta = −0.12, P = .07) and high-order aberrations (beta = −0.04, P = .58) were not significant predictors of mesopic AULCSF. Bland–Altman plots show that photopic CSF Acuity and visual acuity had a mean difference of 0.19 ± 0.01 logMAR with limits of agreement (LOAs) at −0.01 and 0.39 logMAR. Photopic CSF Acuity and 5% contrast acuity had a mean difference of −0.06 ± 0.01 logMAR with LOAs at −0.33 and 0.21 logMAR. Conclusion Quality of vision recovers at postoperative 1 week after LASIK and at postoperative 1 month after PRK-MMC. The standard black-on-white high-contrast, chart-based visual acuity test is weak in predicting quality of vision. The qCSF detects mild-to-moderate visual changes and is suitable for quality of vision assessment following refractive eye surgery.

scholarly journals Frequently Experienced Problems in the Early Stages after Prescribing Rigid Gas Permeable Contact Lenses

2021 ◽  
Vol 20 (4) ◽  
pp. 135-139
Author(s):  
Dong Ho Lee
Keyword(s):  
Visual Acuity ◽  
Foreign Body ◽  
Contact Lenses ◽  
Foreign Body Sensation ◽  
Corneal Curvature ◽  
Slit Lamp ◽  
Body Sensation ◽  
Quality Of Vision ◽  
Slit Lamp Microscopy

Prescribing rigid gas-permeable (RGP) lenses involves a series of processes that determine the most appropriate final lens through the trial use of test lenses based on the results of slit lamp microscopy, measuring refraction and corneal curvature, and corneal topography. The final prescription is reached by judging the dynamic lens movement, adequacy of the tear layer around the lens, corrected vision, and quality of vision. Various problems are encountered soon after prescribing lenses, including foreign body sensation, tear hypersecretion, decreased visual acuity, blurring, visual acuity change, redness, dryness, sudden pain, lens centering, and lens fallout. Here, we examine these problems and how to solve them.

scholarly journals Effect of Photorefractive Keratectomy and Laser in situ Keratomileusis in High Myopia on logMAR Visual Acuity and Contrast Sensitivity

2003 ◽  
Vol 46 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Hana Langrová ◽  
Matthias Derse ◽  
Dagmar Hejcmanová ◽  
Alena Feuermannová ◽  
Pavel Rozsíval ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
High Myopia ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Spherical Equivalent ◽  
Spatial Frequencies ◽  
Quality Of Vision

Purpose: To compare effect of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on contrast sensitivity (CS) and best corrected visual acuity (BCVA) in high myopia. Methods: 38 myopes (PRK) and 31 patients (LASIK) were examined before and 1, 3, 6, and 12 months postoperatively. Mean preoperative spherical equivalent was -8.0 ± 1.7D (PRK) and -9.2 ± 2.1D (LASIK). CS was tested on a computerized system of the Contrast Sensitivity 8010 Type at 6 spatial frequencies (0.74 and 29.55 c/deg), BCVA was measured on logMAR charts. Results: At 12 months postoperatively, mean spherical equivalent was -0.6 ± 1.0D (PRK) and -1.0 ± 0.8D (LASIK). Postoperative values of CS were significantly higher in the PRK group, except for spatial frequencies of 3.69 and 7.39 c/deg up to 3 months postoperatively. The initial significant decrease of BCVA lasted up to 6 months after PRK. In the LASIK group BCVA was not significantly different from its preoperative level at the 3-months follow-up. Conclusions: The significant improvement of CS after PRK suggest that PRK can improve quality of vision in eyes with high myopia. Although recovery of BCVA after LASIK was faster than after PRK, there may be a persistent decrease in CS.

scholarly journals One-year post-operative comparison of visual function and patient satisfaction with trifocal and extended depth of focus intraocular lenses

2021 ◽  
pp. 112067212110697
Author(s):  
Elizabeth M. Law ◽  
Rajesh K. Aggarwal ◽  
Hetal Buckhurst ◽  
Hosam E. Kasaby ◽  
Jonathan Marsden ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Early Period ◽  
Intraocular Lenses ◽  
Depth Of Focus ◽  
Extended Depth Of Focus ◽  
Quality Of Vision ◽  
Significant Difference ◽  
One Year

Purpose To evaluate visual performance with trifocal and extended depth of focus IOL at 1 year post-operatively. Setting BMI Southend Hospital. Design Cohort study. Methods An age-matched cohort of forty subjects bilaterally implanted with the AT LISA 839MP trifocal IOL (20 patients, 40 eyes) and the Tecnis Symfony extended depth of focus IOL (20 patients, 40 eyes) were assessed at 3–6 months and 12–18 months post-operatively. Primary outcome measures were distance (6 m), intermediate (70 cm), near visual acuity (40 cm), and analysis of defocus profiles. Secondary outcomes included contrast sensitivity, Radner reading performance, quality of vision and assessment of halos. Results Distance visual acuity (VA) and defocus areas were similar ( p = 0.07). No significant difference in intermediate VA was noted but the intermediate area of focus was greater in the EDoF (0.31 ± 0.12 LogMAR*m−1) compared to the trifocal (0.22 ± 0.08LogMAR*m−1) ( p = 0.02). However, all near metrics were significantly better in the trifocal group. 80% of trifocal subjects were spectacle independent compared to 50% EDoF subjects. Quality of vision questionnaire found no significant differences between groups, however halo scores were greater at 3–6 months in the trifocal group ( p < 0.01) but no differences were noted at 12–18 months. Conclusions Near vision is significantly better for the trifocal, thus greater levels of spectacle independence. The range of intermediate vision was greater for the EDoF but no difference in intermediate VA. In the early period, differences in contrast sensitivity and halo size/intensity were noted, however, by one-year these measures were not significantly different.

scholarly journals Quality of Vision with Spectacles, Special Silicone Hydrogel and Gas Permeable Contact Lenses in Keratoconic Patients

2013 ◽  
Vol 2 (2) ◽  
pp. 56-59 ◽  
Author(s):  
Jose M González-Méijome ◽  
Sofia Claudia Peixoto-de-Matos ◽  
Antonio Queiros ◽  
Jorge M Jorge ◽  
Alberto Diaz-Rey
Keyword(s):  
Visual Acuity ◽  
Contact Lens ◽  
Contact Lenses ◽  
Soft Contact ◽  
Low Contrast ◽  
Silicone Hydrogel ◽  
Soft Contact Lens ◽  
Quality Of Vision ◽  
Spectacle Correction

ABSTRACT Purpose To evaluate optical quality and visual function in keratoconus patients corrected with RGP contact lenses and a novel special design of silicone hydrogel contact lens. Materials and methods Twelve eyes of six patients with keratoconus were enrolled to experience a new soft contact lens (Soft-K) for keratoconus made of a silicone-hydrogel material and the outcomes were compared to the performance with gas permeable lenses and spectacles. The three situations were compared for monocular and binocular high (100%) and low contrast (10%) ETDRS LogMAR visual acuity and contrast sensitivity function (CSF). Results On average, there was an improvement of more than two lines in visual acuity over spectacle correction and this is statistically significant for both gas permeable (GP) and Soft-K lens (p < 0.001). Visual acuity was not significantly different between GP and Soft-K lens for high contrast acuity but was slightly higher with GP lens for low contrast under binocular conditions. Monocular CSF showed a marked improvement with the Soft-K lens and GP, compared to spectacles correction, particularly for medium and high frequencies; conversely. Conclusion Soft-K silicone hydrogel soft contact lens produces a clinical and statistically significant improvement in visual acuity and contrast sensitivity function over spectacle correction. How to cite this article González-Méijome JM, Peixoto-de- Matos SC, Queiros A, Jorge JM, Diaz-Rey A. Quality of Vision with Spectacles, Special Silicone Hydrogel and Gas Permeable Contact Lenses in Keratoconic Patients. Int J Kerat Ect Cor Dis 2013;2(2):56-59.

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

2018 ◽  
Vol 12 (1) ◽  
pp. 84-93 ◽  
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.

scholarly journals Comparison of post-op quality of vision of spheric IOL and aspheric hydrophilic acrylic yellow tinted intraocular lens implantation following phacoemulsification cataract surgery

2021 ◽  
Vol 11 (2) ◽  
pp. 28-31
Author(s):  
Safdar Hussain ◽  
Asma Batool ◽  
Saba Akram ◽  
Hina Manzoor ◽  
Ayesha Arshad
Keyword(s):  
Visual Acuity ◽  
Standard Deviation ◽  
Cataract Surgery ◽  
Intraocular Lens ◽  
Age Related Macular Degeneration ◽  
Ocular Lens ◽  
Age Related ◽  
Quality Of Vision ◽  
Phacoemulsification Cataract Surgery

Purpose: To compare the post-op visual quality of spheric and aspheric acrylic yellow tinted intraocular lens following phacoemulsification cataract surgery. Place of study: Al-Majeed Laser Eye Hospital. Methods: Total 60 subjects (aged 40-65years) with age related mature cataracts were included. Data was assembled by non-probability convenient sampling technique at Al-Majeed Laser Eye Hospital. All patients presenting with mature cataract were include in this study without any other pathology and fundus abnormality. Pre and post-operative visual acuity was measured by using standard snellen visual acuity testing chart. For the purpose of accuracy repetitive values were taken for each patient. Post-operative vision was recorded one month followed by phacoemulsification. Comparisons was made between spheric and asphereic acrylic yellow tinted intraocular lens by applying (descriptive) statistics and paired sample t test for the analysis of results. Results: Quality of vision was compared post-operatively after implantation of aspheric hydrophilic acrylic IOL and spheric IOL in posterior chamber under the same phaco surgeon. All subjects after intra ocular implantation had better corrected visual acuity of 6/9 and more improved 6/6. There were found statistically differences in recorded visual acuity with aspheric yellow tinted iol implanation and spheric iol (p = 0.15) between the two types of intra-ocular lens. The mean, standard deviation, t-value found with spheric IOL were.1867, .18889, 2.517 respectively. However, of aspheric hydrophilic acrylic intra-ocular lens mean, standard deviation and t values found .800, .13493 and 2.5493 respectively. There was significant variance in statistics and quality of vision between the two types of lenses. Conclusions: This study concludes that post –operative improvement in quality of vision was better with aspheric hydrophilic yellow tinted lenses than spheric iol implantation. Implanting a foldable aspheric acrylic IOL gave much advantage in visual outcome to pseudophakes by protecting retina from light of shorter wavelength and decrease of chromatic aberration under the photopic circumstances particularly in subjects at hazard of age-related macular degeneration (AMD).

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