Clinical Contrast Sensitivity Research Articles

Comparative Validity of LEA Contrast Sensitivity Chart to Pelli-Robson Contrast Sensitivity Chart in Neuroophthalmology Patients

Abstract
 Introduction & Objectives : The Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrast sensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEA contrast sensitivity chart offers a reliable test in a way more practical and portable chart. This condition led to a question of whether we can predict Pelli-Robson score based on the LEA score. This study developed a conversion method to facilitate the transition from the LEA to the Pelli-Robson and validating the conversion score.
 Methods : This study retrospectively examined the relationship between LEA and Pelli-Robson Contrast Sensitivity Test. There were 120 eyes included in this study. We produced a conversion table using the equipercentile equating method. Then, we evaluated the reliability and accuracy of this algorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 Results : LEA scores were converted to Pelli-Robson scores according to a conversion table that achieved a reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6% within 1 point difference from the raw score.
 Conclusion : This study reported a reliable and comparable conversion algorithm for transforming LEA scores into converted estimated Pelli-Robson scores. This method will enhance the utility of existing data in clinical and research settings.

Comparative Validity of LEA Contrast Sensitivity Chart to Pelli-Robson Contrast Sensitivity Chart in Neuroophthalmology Patients

Abstract
 Introduction & Objectives : The Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrast sensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEA contrast sensitivity chart offers a reliable test in a way more practical and portable chart. This condition led to a question of whether we can predict Pelli-Robson score based on the LEA score. This study developed a conversion method to facilitate the transition from the LEA to the Pelli-Robson and validating the conversion score.
 Methods : This study retrospectively examined the relationship between LEA and Pelli-Robson Contrast Sensitivity Test. There were 120 eyes included in this study. We produced a conversion table using the equipercentile equating method. Then, we evaluated the reliability and accuracy of this algorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 Results : LEA scores were converted to Pelli-Robson scores according to a conversion table that achieved a reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6% within 1 point difference from the raw score.
 Conclusion : This study reported a reliable and comparable conversion algorithm for transforming LEA scores into converted estimated Pelli-Robson scores. This method will enhance the utility of existing data in clinical and research settings.

COMPARATIVE VALIDITY OF LEA CONTRAST SENSITIVITY CHART TO PELLI-ROBSON CONTRAST SENSITIVITY CHART IN NEURO-OPHTHALMOLOGY PATIENTS

INTRODUCTION AND OBJECTIVEThe Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrastsensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEAcontrast sensitivity chart offers a reliable test in a way more practical and portable chart. Thiscondition led to a question of whether we can predict Pelli-Robson score based on the LEA score.This study developed a conversion method to facilitate the transition from the LEA to the PelliRobson and validating the conversion score.
 METHODSThis study retrospectively examined the relationship between LEA and Pelli-Robson ContrastSensitivity Test. There were 120 eyes included in this study. We produced a conversion tableusing the equipercentile equating method. Then, we evaluated the reliability and accuracy of thisalgorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 RESULTSLEA scores were converted to Pelli-Robson scores according to a conversion table that achieveda reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6%within 1 point difference from the raw score.
 CONCLUSIONSThis study reported a reliable and comparable conversion algorithm for transforming LEA scoresinto converted estimated Pelli-Robson scores. This method will enhance the utility of existing datain clinical and research settings.

The Effect of Test Distance on Visual Contrast Sensitivity Measured Using the Pelli-Robson Chart.

PurposeThe Pelli-Robson (PR) chart is widely used to measure clinical contrast sensitivity (CS). It is generally believed that PR testing distance is not critical. Here, we examine whether a closer test distance than the usual 1 meter might be better for patients with low vision.MethodsPR CS was measured on two groups: low-vision students (<20 years old) and elder patients (>65 years old). Student PR was measured at 1 meter and at a closer distance d = visual acuity in log10cy/deg (d = 1.5–logMAR). Elder PR was measured at 1 and 3 meters. Grating CS was also measured using the Ohio Contrast Cards (OCCs).ResultsAverage CS was 0.398 log10 units (over one line on the PR chart) higher at the closer distance than at 1 meter for the students, but there was no effect of 1 vs. 3 meters test distance for the elders. The equivalent spatial frequencies of the PR letters at 1 meter were near the acuity limits of students with low vision, but were near the peak of the elders’ CS functions. Especially for students with low vision, PR CS was below OCC CS, even when PR was tested at a closer distance.ConclusionsPR CS should be measured at a distance in meters that is equal to the patient's letter acuity in cy/deg, or 1.5–logMAR.Translational RelevanceContrast sensitivity is highly associated with quality of life, and it is important to measure it accurately. Using a closer distance, or measuring grating CS, can reveal visual abilities missed when patients with low vision are tested using PR at 1 meter.

Clinical Contrast Sensitivity Function in Patients with Infantile Nystagmus Syndrome Before and After Eye Muscle Surgery

Clinical Contrast Sensitivity Function in Patients with Infantile Nystagmus Syndrome Before and After Eye Muscle Surgery

Clinical Contrast Sensitivity Testing in Patients With Infantile Nystagmus Syndrome Compared With Age-Matched Controls

To compare contrast sensitivity using a commercially available technique between patients with infantile nystagmus syndrome (INS) and controls. Prospective, comparative case series. The functional acuity contrast test (FACT) was used binocularly in patients with INS and aged-matched controls with best acuity under normal lighting using a progression of high-quality sine wave grating size changes with increasing spatial frequencies. Nine INS patients aged 5 to 11 years and 25 controls were tested. The INS patients' best binocular acuity ranged from 20/125 to 20/30, and that of the controls was 20/25 or better. When compared with age-matched controls, INS patients displayed deficiencies in contrast sensitivity syndrome using the FACT test. The FACT or a similar testing system may have potential as a commercially available outcome measure in clinical trials in patients with INS.

The impact of acuity on performance of four clinical measures of contrast sensitivity in Alzheimer's disease.

Investigations of contrast sensitivity losses in Alzheimer's disease (AD) have yielded mixed findings, with some investigators reporting deficits and others not. Potential reasons for these discrepancies include differences between samples and assessments utilized and the failure of some investigators to account for acuity differences between groups. To investigate these issues, we administered four clinical contrast sensitivity assessments to the same group of AD patients and elderly control participants and examined the impact of acuity on performance for each assessment. Results revealed group differences across the spatial frequency range. Further, group acuity differences significantly affected performance on two of the four measures (the Regan and the Vistech but not on the Pelli-Robson or Freiburg assessments). Information regarding the availability of established age norms, test-retest reliability data, and other factors including the time, cost, and training needed to administer each measure is provided to aid clinicians and researchers in their search for an effective measure of contrast sensitivity.

Contrast sensitivity in ocular hypertension and glaucoma.

Forty-eight patients aged from 60 to 69 years (58 eyes) with ocular hypertension (OHT) or primary open-angle glaucoma (POAG) and a control group of 16 persons of the same ages (26 eyes) were studied with a clinical contrast sensitivity test, the Vistech 6500 test. No significant differences could be found between the normal and OHT or POAG eyes in any of the spatial frequencies. The group of newly found POAG eyes showed the greatest difference from the normals, but this difference did not reach the level of significance in any of the spatial frequencies.

Clinical contrast sensitivity evaluation in visually impaired children

Clinical contrast sensitivity evaluation in visually impaired children

High and low contrast acuity and clinical contrast sensitivity tested in a normal population.

Visual acuities obtained with a high contrast Bailey-Lovie chart (HCBL) and a low contrast Bailey-Lovie chart (LCBL) were compared with clinical contrast sensitivity function (CSF) measurements in a group of normal subjects with a wide range of refractive errors. We found high and significant correlations for the measurements obtained with the visual acuity tests, and between measurements obtained with the acuity tests and the CSF chart. These results indicate that the CSF test provides little additional information as a screening test in routine practice, and could probably be restricted in its use to patients in whom ocular disease is suspected.

A forced-choice test improves clinical contrast sensitivity testing.

Decreased contrast sensitivity has been demonstrated in early glaucoma, but the deficit in not regularly observed. We designed a prototype for a forced-choice printed test and evaluated it with several other measures of contrast sensitivity. The results also bear on the pattern of loss and the variables which effect performance. Mildly glaucomatous patients show at 6 db (50%) loss of contrast sensitivity at all spatial frequencies tested compared with age matched controls. Moving gratings give the same information as stationary ones, and practice effects are negligible. Contrast sensitivity at or below 2 cycles/degree is poorly correlated with visual acuity and does not change with age in the forced-choice test. Subjective judgment made the apparent contrast threshold higher, age dependent, and more variable, particularly at higher spatial frequencies. The pattern of variability can explain some reports of insignificant effects and why low spatial frequency contrast sensitivity detects glaucoma better than visual acuity. Methods correlated so poorly, despite high reliabilities, that uncontrolled biases must be suspected in subjective measures. Our new forced-choice format was superior to all other tests on at least one formal criterion and always at least equal to them. Improvements in contrast sensitivity screening tests are thus indicated.