Cataract Extraction, Corneal Astigmatism
Conditions
Keywords
Corneal astigmatism, post-cataract surgery, visual performance, Corneal astigmatism 0.5-0.75 Diopter
Brief summary
To assess visual performance in patients with low levels (0.5-0.75 Diopters) of corneal astigmatism.
Interventions
OTHERVisual performance measures
Collection of visual performance measures in subjects with low levels of astigmatism.
Sponsors
Alcon Research
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
50 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* 50-75 years of age * Proof of eye exam within the last 12 months * Operated for uncomplicated, age-related cataracts \>3 months * Corneal astigmatism of 0.5-0.75 diopter
Exclusion criteria
* Previous ocular or refractive surgery/trauma * Clinically severe corneal dystrophy * Amblyopia * Degenerative visual disorders
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| High and Low Contrast Acuity | Day of study visit | Visual acuity differences between subjects tested with full correction and spherical equivalent (SE) correction at contrast levels of 9% and 25% (low contrast acuity) and 100% (high contrast acuity). LogMAR is the logarithm of the minimum angle of resolution. A lower logMAR value indicates better VA. These measurements were performed under photopic conditions by means of 9%, 25%, and 100% contrast ETDRS (Early Treatment Diabetic Retinopathy Study) charts (Vector Vision). |
| Contrast Sensitivity | Day of Study Visit | Contrast Sensitivity (CS) differences between subjects tested with full correction & spherical equivalent (SE) correction. CS is the measurement of one's ability to detect slight changes in luminance before it becomes indistinguishable. CS is measured in logarithmic units by means of an illuminated box, the CSV 1000 by Vector Vision. Testing was performed under photopic conditions (no glare) & mesopic conditions (with & without glare), and was measured at four spatial frequencies of 3, 6, 9, and 12 cycles per degree (cpd). A higher value for the logarithmic units translates to better CS. |
| Reading Acuity and Speed | Day of Study Visit | Reading Acuity and Speed differences between subjects tested with full correction and spherical equivalent (SE) correction. Reading Acuity was measured using the Radner reading charts, which are logarithmically scaled at different acuity levels (print sizes), and expressed in terms of logRAD (logrithmic Reading Acuity Determination). Reading speed was measured in words per minute (wpm). The results were presented as Average Reading Speed by Print Size (logRAD). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Visual Performance Measures Collection of visual performance measures in subjects with low levels of astigmatism. | 40 |
| Total | 40 |
Baseline characteristics
| Characteristic | Visual Performance Measures |
|---|---|
| Age, Customized | 40 Participants |
| Sex: Female, Male Female | 24 Participants |
| Sex: Female, Male Male | 16 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Contrast Sensitivity
Contrast Sensitivity (CS) differences between subjects tested with full correction & spherical equivalent (SE) correction. CS is the measurement of one's ability to detect slight changes in luminance before it becomes indistinguishable. CS is measured in logarithmic units by means of an illuminated box, the CSV 1000 by Vector Vision. Testing was performed under photopic conditions (no glare) & mesopic conditions (with & without glare), and was measured at four spatial frequencies of 3, 6, 9, and 12 cycles per degree (cpd). A higher value for the logarithmic units translates to better CS.
Time frame: Day of Study Visit
Population: Data was collected for 40 eyes in 40 subjects. Only one operative eye of each subject was included in the study. If both eyes qualified, the dominant eye was selected.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Visual Performance Measures | Contrast Sensitivity | Mesopic 3 cycles per degree (cpd) | -0.047 Logrithmic Units | Standard Deviation 0.2917 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic 6 cpd | 0.0896 Logrithmic Units | Standard Deviation 0.3575 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic 9 cpd | 0.0038 Logrithmic Units | Standard Deviation 0.3597 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic 12 cpd | -0.009 Logrithmic Units | Standard Deviation 0.371 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic with glare 3 cpd | 0.0176 Logrithmic Units | Standard Deviation 0.2271 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic with glare 6 cpd | 0.0241 Logrithmic Units | Standard Deviation 0.3146 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic with glare 9 cpd | 0.0183 Logrithmic Units | Standard Deviation 0.2728 |
| Visual Performance Measures | Contrast Sensitivity | Mesopic with glare 12 cpd | 0.0669 Logrithmic Units | Standard Deviation 0.2559 |
| Visual Performance Measures | Contrast Sensitivity | Photopic 3 cpd | 0.0163 Logrithmic Units | Standard Deviation 0.2257 |
| Visual Performance Measures | Contrast Sensitivity | Photopic 6 cpd | 0.0181 Logrithmic Units | Standard Deviation 0.2539 |
| Visual Performance Measures | Contrast Sensitivity | Photopic 9 cpd | 0.0479 Logrithmic Units | Standard Deviation 0.3866 |
| Visual Performance Measures | Contrast Sensitivity | Photopic 12 cpd | 0.0321 Logrithmic Units | Standard Deviation 0.3215 |
Primary
High and Low Contrast Acuity
Visual acuity differences between subjects tested with full correction and spherical equivalent (SE) correction at contrast levels of 9% and 25% (low contrast acuity) and 100% (high contrast acuity). LogMAR is the logarithm of the minimum angle of resolution. A lower logMAR value indicates better VA. These measurements were performed under photopic conditions by means of 9%, 25%, and 100% contrast ETDRS (Early Treatment Diabetic Retinopathy Study) charts (Vector Vision).
Time frame: Day of study visit
Population: Data was collected for 40 eyes in 40 subjects. Only one operative eye of each subject was included in the study. If both eyes qualified, the dominant eye was selected.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Visual Performance Measures | High and Low Contrast Acuity | 9% Contrast Acuity | 0.0855 logMAR | Standard Deviation 0.1111 |
| Visual Performance Measures | High and Low Contrast Acuity | 25% Contrast Acuity | 0.065 logMAR | Standard Deviation 0.1019 |
| Visual Performance Measures | High and Low Contrast Acuity | 100% Contrast Acuity | 0.082 logMAR | Standard Deviation 0.1013 |
Primary
Reading Acuity and Speed
Reading Acuity and Speed differences between subjects tested with full correction and spherical equivalent (SE) correction. Reading Acuity was measured using the Radner reading charts, which are logarithmically scaled at different acuity levels (print sizes), and expressed in terms of logRAD (logrithmic Reading Acuity Determination). Reading speed was measured in words per minute (wpm). The results were presented as Average Reading Speed by Print Size (logRAD).
Time frame: Day of Study Visit
Population: Data was collected for 40 eyes in 40 subjects. Only one operative eye of each subject was included in the study. If both eyes qualified, the dominant eye was selected.
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) |
|---|---|---|---|
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line -0.1 | 2.7469 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0 | 7.3292 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.1 | 11.7498 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.2 | 17.5404 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.3 | 10.1643 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.4 | 13.4166 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.5 | 12.7487 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.6 | 11.9005 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.7 | 15.1714 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.8 | 9.7203 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 0.9 | 11.4863 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 1.1 | 16.4043 words per minute |
| Visual Performance Measures | Reading Acuity and Speed | logRAD Line 1.2 | 8.8952 words per minute |