scholarly journals Comparison of contrast sensitivity in myopic patients using spectacle and contact lens correction

2021 ◽  
Vol 15 (5) ◽  
pp. 951-953
Author(s):  
Sadaf Qayyum ◽  
Zubair Wahab ◽  
Rabia Saeed ◽  
Anbar Zulfiqar ◽  
Ayisha Shakeel ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Contact Lens ◽  
Contact Lenses ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Spectacle Lens ◽  
Optical Correction ◽  
Eye Examination ◽  
Optical Defocus

Aim: To compare the contrast sensitivity in different categories of myopia using two different optical correction spectacles and contact lens correction. Methods: This cross-sectional study in design was conducted from August 2018 to May 2019 at the Ophthalmology Department of Madinah Teaching Hospital Faisalabad.45 subjects corrected with spectacles lenses and contact lenses all had corrected visual acuity of 6/9 or better were studied.The extent of myopia determined the three groups. All individuals were subjected to spectacles and Contact lens correction using slitlamp for anterior eye examination and for the fundus examination. The assessment of visual acuity was carried out by the Snellen vision Chart at 6m distance and contrastssensitivity was tested by Pelli- Robson chart. Results: Results showed a significant relationship between contrast sensitivity and type of optical correction. There were significant results of the independent t-test for spectacle and contact lenses 0.00 (p<0.005). However, the mean contrast sensitivity was better for all the three groupswith contact lens correction as compared to spectacle lens correction.Contact lenses provide better contrast sensitivity than spectacle lenses. Conclusion: Comparison between contact lens and spectacle correction was done and better quality contact lenses reduce optical defocus and give better results of contrast sensitivity. Results also concluded that loss of contrast sensitivity will be interpreted as early loss of retinal functions in severe myopes. Keywords: Myopia, Contrast sensitivity, Spectacle lens, Contact lens

scholarly journals Visual Acuity in Myopes with Standard and Reversed Contrast Optotypes

2017 ◽  
Vol 71 (1-2) ◽  
pp. 22-26
Author(s):  
Gatis Ikaunieks ◽  
Anete Petrova ◽  
Karola Panke ◽  
Gunta Krūmiņa
Keyword(s):  
Visual Acuity ◽  
Contact Lens ◽  
Contact Lenses ◽  
Optical Correction ◽  
Optical Defocus ◽  
Spectacle Correction ◽  
Low Order

Abstract The aim of this study was to assess the visual acuity of myopes with standard and reversed contrast optotypes and to determine how the visual acuity of myopes is affected by optical defocus and the type of optical correction, either contact lenses or spectacles. Twenty-three myopic subjects (18 and 23 years old) with uncorrected vision had their visual acuity assessed with both standard and reversed contrast optotypes. The study also included 10 myopes with contact lens as well as habitual spectacle correction. The visual acuity for myopes with uncorrected vision was better with reversed than standard contrast optotypes. Better reversed contrast than standard contrast visual acuity was obtained also with spectacle and contact lens correction. This result could be due in part to low order aberrations (optical defocus) in myopes spectacle or contact lenses correction.

scholarly journals The impact of irregular corneal shape parameters on visual acuity and contrast sensitivity

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Sanita Liduma ◽  
Artis Luguzis ◽  
Gunta Krumina
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Cross Sectional Study ◽  
Shape Parameters ◽  
Corneal Surface ◽  
Cross Sectional ◽  
Corneal Shape ◽  
Different Diameters ◽  
The Impact ◽  
Corneal Apex

Abstract Background To understand which irregular corneal parameters determine the visual quality in keratoconus subjects. Methods The cross-sectional study examined the eyes of 44 subjects, graded from the first to third keratoconus stages by Amsler-Krumeich classification. We obtained measurements in two ways: (a) by projecting two perpendicular axes onto a cornea (first, through the central point of the cornea and keratoconus apex; second, as the perpendicular axis) to read the elevation values at points on these axes as parameters characterising the corneal surface; (b) by projecting circles with different diameters around the central part of the cornea (1, 2, and 3 mm) and reading elevation values at points equally displaced on these circles as parameters characterising an anterior surface slope. Irregular corneal shape parameters’ correlations with visual acuity and contrast sensitivity were determined in order to understand which corneal slope parameter has the strongest correlation with visual acuity and contrast sensitivity. Results Parameters characterising the corneal surface’s correlations with contrast sensitivity were from r = 0.25 (p = 0.03) at 3 cpd to r = 0.47 (p < 0.01) at 9 cpd for the highest elevation and from r = 0.33 (p = 0.09) at 5 cpd to r = 0.40 (p < 0.01) at 11 cpd for the lowest elevation in all subjects together, while for visual acuity the parameters were r = 0.30 (p < 0.01) for the highest elevation and r = 0.21 (p = 0.06) for the lowest elevation in all subjects together. The correlation between contrast sensitivity and the highest and lowest corneal point in all measured cornea was stronger for subjects with a peripheral corneal apex than for those with a central apex. In keratoconus subjects, contrast sensitivity displayed a strong correlation with slope in the central part of the cornea (with a radius of 1 mm) ranging from 0.48 (p < 0.01) at 3 cpd to 0.61 (p < 0.01) at 9 cpd. Conclusion Contrast sensitivity has a higher correlation with corneal shape parameters than with visual acuity. Subjects with a peripheral corneal apex had stronger correlations with visual acuity and contrast sensitivity than did subjects with a central apex. In keratoconus subjects, the strongest correlation was for contrast sensitivity and elevation (slope) in the region within a 1 mm radius of the corneal centre in the opposite direction of the keratoconus apex (direction (ax) CB).

scholarly journals Microbiological analysis of contact lens cases and effective health behaviors

2020 ◽  
Vol 7 (2) ◽  
pp. e17-e17
Author(s):  
Fatemeh Eslami ◽  
Hamid Reza Ghasemi Basir ◽  
Abbas Moradi ◽  
Mina Bayat
Keyword(s):  
Health Behaviors ◽  
Contact Lens ◽  
Bacterial Contamination ◽  
Contact Lenses ◽  
Significant Proportion ◽  
Enterobacter Aerogenes ◽  
Cross Sectional Study ◽  
Microbial Culture ◽  
Microbiological Analysis ◽  
Cross Sectional

Introduction: Contact lenses are increasingly being used for cosmetic or therapeutic purposes, followed by subsequent contamination and complications such as keratitis. The lens case is one of the most common places to find the cause of contamination. Objectives: This study was designed to evaluate the health behaviors affecting the lens case contamination and its relationship with the result of lens case culture which can help in prevention of complications. Patients and Methods: In this cross-sectional study that was performed in northwest of Iran, 150 asymptomatic participants were assessed for health behaviors affecting the lens case contamination and their lens cases were sampled for culture and antibiogram. Data were analyzed with SPSS-16 software. Results: The frequency of positive microbial culture in medical and cosmetic contact lens cases was 30.7% and 66.8%, respectively and 32.7% in general. Among the isolated bacteria observed in positive cultures, Alcaligenes,Enterobacter aerogenes, gram-positive Diphtheroid bacilli, Pseudomonas aeruginosa and Staphylococcus epidermidis were the most common microorganisms, respectively. Conclusion: A significant proportion of contact lens cases, especially those used for cosmetic purposes had bacterial contamination. Failure to replace the lens case for more than 9 months and the mismatch of the lens solution brand with its storage case will increase bacterial contamination. Washing the lens case with soap and water, and drying it after washing, will reduce bacterial contamination.

Multifocal Corneal Ablation (Supracor) in Hyperopic Presbyopia: 1-Year Results in a Cross-Sectional Study

2016 ◽  
Vol 27 (4) ◽  
pp. 438-442 ◽  
Author(s):  
Torsten Schlote ◽  
Alexander Heuberger
Keyword(s):  
Visual Acuity ◽  
Patient Satisfaction ◽  
Side Effects ◽  
Contrast Sensitivity ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Distance Visual Acuity ◽  
One Year ◽  
Distance Vision

Purpose To evaluate the efficacy and safety of the multifocal excimer laser corneal ablation profile (the Supracor procedure) in hyperopic presbyopia 1 year after laser treatment. Methods This prospective, consecutive, one-center, cross-sectional study included 20 patients with hyperopic presbyopia 1 year after treatment with the Supracor procedure. The main outcome measures were monocular uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA), photopic contrast sensitivity (Pelli-Robson charts), patient satisfaction, and functioning at 12 months. Results Thirty-nine eyes of 20 patients (mean age 59 ± 7.2 years) were treated. Mean UDVA improved from 0.56 ± 0.31 (mean 0.34 logMAR) preoperatively to 0.9 ± 0.15 (mean 0.06 logMAR) 12 months after surgery. Mean UNVA increased from 0.15 ± 0.07 (mean 0.84 logMAR) before surgery to 0.62 ± 0.24 (mean 0.23 logMAR) 12 months after treatment. Four eyes lost 2 lines of corrected distance visual acuity (10.3%). Monocular photopic contrast sensitivity was within age-correlated normal range (Pelli-Robson chart, mean contrast sensitivity 1.83 ± 0.18). A total of 75% of the patients would undergo Supracor again (1 not, 4 perhaps). The most frequently reported side effects were increased glare, reduced distance vision, and fluctuations in vision. Most patients used artificial tears. Conclusions One year after Supracor, UDVA and UNVA improved markedly, photopic contrast sensitivity was in normal age-correlated range, and the majority of patients (75%) was satisfied with the results. Side effects like loss of distance vision, fluctuations of vision, and increased glare have a greater influence on patient satisfaction than the improvement of spectacle-free near vision.

scholarly journals Study on visual function comparison between ametropes and emmetropes after visual correction

2021 ◽  
Vol 7 (2) ◽  
pp. 428-432
Author(s):  
L K Lali ◽  
R Abirama Sundari ◽  
R Shankar
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Refractive Error ◽  
Axial Length ◽  
Reading Speed ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Visual Functions ◽  
Significant Difference

Studies had also shown that 86% of children with refractive error living in rural area are without correction as many are unaware of their problem. Refractive error by itself plays a significant role on one’s quality of life and literature had also proven it. To study the visual functions in ametropes with 6/6 BCVA and compare it with emmetropes.: A cross-sectional study was conducted for a period of one year. All the 200 subjects were tested for refractive error using auto refractor, distance and near visual acuity was assessed with the ETDRS chart, contrast sensitivity was assessed using LEA symbol chart, color vision was assessed using FM 15 online test and field vision was tested using Bjerrum tangent screen, stereopsis was examined using TNO cards, morphometric measurements was done by measuring the axial length using A scan and the K reading was obtained using auto keratometer and finally the functional assessment was analysed using the reading and writing speed. A total of 200 subjects with 100 ametropes and 100 emmetropes were included in our study. Colour vision, near point accommodation, near point convergence, axial length were significantly altered in ametropes. Contrast sensitivity, steropsis and reading speed were significantly reduced in ametropes compared to emmetropes. There was no significant difference in visual functions between different types refractive error subjects like myopia, hypermetropia and astigmatism. The present study proves that visual acuity alone is not an indicator for assessing the quality of vision instead the complete visual functions has to be screened on all patients reporting with refractive error.

scholarly journals Stratification of Individual Symptoms of Contact Lens–Associated Dry Eye Using the iPhone App DryEyeRhythm: Crowdsourced Cross-Sectional Study

10.2196/18996 ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. e18996 ◽  
Author(s):  
Takenori Inomata ◽  
Masahiro Nakamura ◽  
Masao Iwagami ◽  
Akie Midorikawa-Inomata ◽  
Jaemyoung Sung ◽  
...  
Keyword(s):  
Risk Factors ◽  
Personalized Medicine ◽  
Dry Eye ◽  
Contact Lens ◽  
Contact Lenses ◽  
Cross Sectional Study ◽  
Subjective Symptoms ◽  
Sectional Study ◽  
Odds Ratios ◽  
Cross Sectional

Background Discontinuation of contact lens use is mainly caused by contact lens–associated dry eye. It is crucial to delineate contact lens–associated dry eye's multifaceted nature to tailor treatment to each patient’s individual needs for future personalized medicine. Objective This paper aims to quantify and stratify individual subjective symptoms of contact lens–associated dry eye and clarify its risk factors for future personalized medicine using the smartphone app DryEyeRhythm (Juntendo University). Methods This cross-sectional study included iPhone (Apple Inc) users in Japan who downloaded DryEyeRhythm. DryEyeRhythm was used to collect medical big data related to contact lens–associated dry eye between November 2016 and January 2018. The main outcome measure was the incidence of contact lens–associated dry eye. Univariate and multivariate adjusted odds ratios of risk factors for contact lens–associated dry eye were determined by logistic regression analyses. The t-distributed Stochastic Neighbor Embedding algorithm was used to depict the stratification of subjective symptoms of contact lens–associated dry eye. Results The records of 4454 individuals (median age 27.9 years, SD 12.6), including 2972 female participants (66.73%), who completed all surveys were included in this study. Among the included participants, 1844 (41.40%) were using contact lenses, and among those who used contact lenses, 1447 (78.47%) had contact lens–associated dry eye. Multivariate adjusted odds ratios of risk factors for contact lens–associated dry eye were as follows: younger age, 0.98 (95% CI 0.96-0.99); female sex, 1.53 (95% CI 1.05-2.24); hay fever, 1.38 (95% CI 1.10-1.74); mental illness other than depression or schizophrenia, 2.51 (95% CI 1.13-5.57); past diagnosis of dry eye, 2.21 (95% CI 1.63-2.99); extended screen exposure time >8 hours, 1.61 (95% CI 1.13-2.28); and smoking, 2.07 (95% CI 1.49-2.88). The t-distributed Stochastic Neighbor Embedding analysis visualized and stratified 14 groups based on the subjective symptoms of contact lens–associated dry eye. Conclusions This study identified and stratified individuals with contact lens–associated dry eye and its risk factors. Data on subjective symptoms of contact lens–associated dry eye could be used for prospective prevention of contact lens–associated dry eye progression.

scholarly journals Awareness of the Practice and Use of Contact Lenses amongst Students of the Health Faculty at Jazan University during the COVID-19 Pandemic

2021 ◽  
pp. 371-382
Author(s):  
Ismail Abuallut ◽  
Abdulaziz A. Hakami ◽  
Mohammed I. Alameer ◽  
Mohammed O. Shami ◽  
Nasser M. Hakami ◽  
...  
Keyword(s):  
Contact Lens ◽  
Bacterial Infections ◽  
Contact Lenses ◽  
Good Practice ◽  
Cross Sectional Study ◽  
Hygiene Practice ◽  
Cross Sectional ◽  
Common Information ◽  
Hygiene Practices ◽  
And Training

Background: Contact lenses are medical devices which are used as an alternative to spectacles to correct problems with eyesight. Poor hygienic handling of these lenses poses an ocular health risk. Increased popularity and usage of contact lenses in combination with insufficient cleanliness results in increased bacterial infections of the eye, even resulting in blindness. Materials and Methods: We employed a quantitative cross-sectional study, where we used questionnaires to gather data. We conducted the study among students of the Health Faculty at Jazan University where we recruited 361 participants. Using the questionnaires, we assessed the use of contact lenses and the hygiene practice when handling them among the participants. To the best of our knowledge, only one study has been conducted in the Jazan region to assess contact lens awareness and practice, which can be consider as a gap of knowledge that make our study can be consider a vital observation about usage of contact lens in the Jazan region. Results: We found that 52.6% of the participants use contact lenses. Among those it is predominantly females who use contact lenses, and their motivation is primarily for cosmetic reasons. We further found that the majority of contact lens users exhibit good hygiene practices when handling contact lenses. However, there remains more than a quarter of participants for whom the hygiene practice is poor to moderately good. Conclusion: The majority of participants 172 (84.7%) had good practice level regarding wearing contact lenses. Considering the significant fraction of participants who showed inadequate hygiene practice, we recommend better information and training for those who use contact lenses. This information and training should be predominantly made available on the internet or through contact lens vendors, as these are the most common information channels among the participants.

Visual Acuity, Contrast Sensitivity Function, and Twilight Vision of Soft and Rigid Gas-Permeable Contact Lens Wearers

2020 ◽  
Author(s):  
Iva Krolo ◽  
Aida Kasumović ◽  
Ivana Radman ◽  
Ivan Sabol ◽  
Maja Malenica Ravlić ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Prospective Study ◽  
Contrast Sensitivity ◽  
Contact Lens ◽  
Contact Lenses ◽  
Sensitivity Function ◽  
Visual Performance ◽  
Corrected Visual Acuity ◽  
Before And After ◽  
Spectacle Correction

Abstract Aim of study was to assess the visual acuity (VA) before and after correction with soft and rigid gas permeable contact lenses (CLs) in healthy subjects, as well as their visual perfomance, including contrast sensitivity function (CSF), and twilight vision (TV). 60 eyes corrected with soft contact lenses (SCLs) and 38 eyes with rigid gas permeable contact lenses (RGPCLs) were enrolled in this prospective study. The following measurements were obtained: best spectacle–corrected visual acuity (BSCVA), best contact lens-corrected visual acuity (BCLCVA), TV, and CSF. Parameters were evaluated before and after CLs fitting and 2 months after the baseline. Exclusion criteria included anterior and posterior segment pathology, amblyopia, prior CLs wear, and ocular surgery. When analyzing TV, results showed superiority of CLs to the spectacle correction, with no statistical difference regarding the CL type. As for the CSF, RGPCLs were superior to both SCLs and spectacle correction. Visual performance was better in group fitted with RGPCLs oppose to SCLs group. CL wear improved visual performance compared to spectacles. This is the first prospective study to simultaneously investigate changes in VA, CS, and TV in SCL and RGCL wear, suggesting RGPCLs as the correction of choice for achieving optimal visual performance.

scholarly journals The Impact of Irregular Corneal Shape Parameters on Visual Acuity and Contrast Sensitivity

2020 ◽  
Author(s):  
Sanita Liduma ◽  
Artis Luguzis ◽  
Gunta Krumina
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Cross Sectional Study ◽  
Shape Parameters ◽  
Corneal Surface ◽  
Cross Sectional ◽  
Corneal Shape ◽  
Different Diameters ◽  
The Impact ◽  
Corneal Apex

Abstract Background: To understand which irregular corneal parameters determine the visual quality in keratoconus subjects.Methods: The cross-sectional study examined the eyes of 44 subjects, graded from the first to third keratoconus stages by Amsler-Krumeich classification. We obtained measurements in two ways: (a) by projecting two perpendicular axes onto a cornea (first, through the central point of the cornea and keratoconus apex; second, as the perpendicular axis) to read the elevation values at points on these axes as parameters characterising the corneal surface; (b) by projecting circles with different diameters around the central part of the cornea (1, 2, and 3 mm) and reading elevation values at points equally displaced on these circles as parameters characterising an anterior surface slope. Irregular corneal shape parameters’ correlations with visual acuity and contrast sensitivity were determined in order to understand which corneal slope parameter has the strongest correlation with visual acuity and contrast sensitivity.Results: Parameters characterising the corneal surface’s correlations with contrast sensitivity were from r=0.25 (p=0.03) at 3 cpd to r=0.47 (p<0.01) at 9 cpd for the highest elevation and from r=0.33 (p=0.09) at 5 cpd to r=0.40 (p<0.01) at 11 cpd for the lowest elevation in all subjects together, while for visual acuity the parameters were r=0.30 (p<0.01) for the highest elevation and r=0.21 (p=0.06) for the lowest elevation in all subjects together. The correlation between contrast sensitivity and the highest and lowest corneal point in all measured cornea was stronger for subjects with a peripheral corneal apex than for those with a central apex. In keratoconus subjects, contrast sensitivity displayed a strong correlation with slope in the central part of the cornea (with a radius of 1 mm) ranging from 0.48 (p<0.01) at 3 cpd to 0.61 (p<0.01) at 9 cpd.Conclusion: Contrast sensitivity has a higher correlation with corneal shape parameters than with visual acuity. Subjects with a peripheral corneal apex had stronger correlations with visual acuity and contrast sensitivity than did subjects with a central apex. In keratoconus subjects, the strongest correlation was for contrast sensitivity and elevation (slope) in the region within a 1 mm radius of the corneal centre in the opposite direction of the keratoconus apex (direction (ax) CB).

scholarly journals Association of Low Visual Acuity and Head Injury among the Undergraduate Students of Bingham University, Karu, Nigeria

2021 ◽  
Vol 12 (3) ◽  
pp. 76-83
Author(s):  
Angela Danborno ◽  
◽  
Ifunanya Ofoka ◽  
Victor Eje ◽  
◽  
...  
Keyword(s):  
Visual Acuity ◽  
Head Injury ◽  
Undergraduate Students ◽  
Educational Status ◽  
Cross Sectional Study ◽  
Anthropometric Parameters ◽  
Cross Sectional ◽  
Eye Examination ◽  
The Right ◽  
The Relationship

A laboratory-based cross-sectional study was conducted among Bingham University undergraduate students, Karu, to investigate the proportion of visual acuity (VA) among the students. The study aimed at investigating an association between head injury with low VA of students whose parent’s use medicated eye glasses. A total of 262 undergraduate students participated in the study. A predesigned, pre-tested, self-administered questionnaire was filled by the students. Eye examination using the optotype Snellen E Chart followed and the VA of the right (VARE) and left eyes (VALE) were tested separately. A regression and correlation model was used to assess the relationship between head injury and low VA. Head injury at one point of time in their life was strongly associated with low VA for both eyes (VARE, r = 0.524, R2 = 0.274, p = 0.040; VALE, r = 0.0.531, R2 = 0.282 p = 0.010). Parents’ use of medicated eye glasses was also associated with low VA of students (VARE p = 0.009; VALE p < 0.001). Our results showed that students that had any form of head injury at any point in their life either as a child, teenager or an adult, were more likely to have low VA. However, the educational status of parents, anthropometric parameters and ethnicity had no association with low VA. We conclude that any form of head injury, at any point in one’s life, and parent’s use of eye glasses are risk factors for low VA.

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