OBJECTIVE: To study the application value of contrast vision in identifying the malingering decreased vision in the practice of clinical forensic medicine. METHODS: Thirty-one young and middle aged volunteers were selected and divided randomly into group 1 (16 persons with 32 eyes) and group 2 (15 persons with 30 eyes). The optotype contrast was 100%, 25%, 10% and 5%, respectively. The contrast vision of group 1 was tested. The contrast vision of group 2 was tested as follows: (1) the volunteers cooperated without inspector's interference; (2) the volunteers cooperated under inspector's interference; (3) the volunteers disguised decreased vision without inspector's interference; (4) the volunteers disguised decreased vision under inspector's interference. The data was then analyzed by statistics. RESULTS: There was a close correlation between contrast vision and contrast. As the contrast decreased, the vision acuity also decreased. The contrast vision curve of former two methods showed a good reproducibility while the contrast vision curve of latter two methods had a bad reproducibility. CONCLUSION The repetition of contrast curve with or without inspector's interference can be used to discriminate malingering vision. The acquired contrast curves can be provided to the court as direct evidence and can help enhance the verification conclusion.
Adult ; Contrast Sensitivity/physiology* ; Diagnosis, Differential ; Female ; Humans ; Male ; Malingering/psychology* ; Reproducibility of Results ; Sensitivity and Specificity ; Severity of Illness Index ; Vision Tests/statistics & numerical data* ; Vision, Binocular ; Vision, Low/psychology* ; Visual Acuity ; Young Adult

PURPOSE: To evaluate the correlation of the distance Krimsky test and the alternate prism cover test (APCT) for the distance deviation in patients with horizontal strabismus. METHODS: Forty patients with horizontal strabismus (20 esotropia and 20 exotropia) were included in this study. Patients with a variable angle of deviation, vertical angle over 5 prism diopters, impaired binocular vision, or poor cooperation were excluded. We instructed the patient to look a target 6 meters away, and applied a prism over the patient's dominant eye while flashing a light source 33 centimeters from the middle of both eyebrows. When the corneal light reflexes were located on the center of each cornea, we measured the angle of deviation. We defined this method as 'distance Krimsky test,' and the angle measured by this method was compared with the conventional Krimsky test and APCT at distance. We analyzed the accuracy and intra- and inter-observer reliability. RESULTS: The angle of strabismus measured by the distance Krimsky test showed a significant agreement and correlation with the deviation angle measured by the APCT. We elicited the correlation gradient between the angle measured by the distance Krimsky test and the APCT. In addition, the distance Krimsky test showed significant intra- and inter-observer reliabilities. CONCLUSIONS: The distance Krimsky test is expected to be more useful than the Krimsky test in measuring the distance angle of deviation for patients with strabismus in whom it is difficult to measure the angle of deviation using the APCT. The distance Krimsky test can be an accurate and useful test through the improvement of proficiency of examiners and the establishment of individualized normative data.
Adolescent ; Adult ; Child ; Esotropia/*diagnosis/physiopathology ; Exotropia/*diagnosis/physiopathology ; Female ; Humans ; Male ; Observer Variation ; Social Distance ; Strabismus/diagnosis/physiopathology ; Vision Tests/*methods/standards/statistics & numerical data ; Vision, Binocular ; Young Adult

This study evaluated the visual quality after wavefront-guided laser in situ keratomileusis (LASIK) for treating myopia. Thirty-two eyes with moderate myopia (-5.78~-2.17D) and 25 eyes with high myopia (-7.78~-6.17D) were prospectively reviewed. The contrast sensitivity (CS), glare and the total higher order aberrations (HOA) were measured before and 1 week, 1 month and 2 months after LASIK. The pupil diameter was measured at day- and night-time illumination. The CS and glare at all spatial frequencies were not reduced after wavefront-guided LASIK (p<0.05) and the difference between the moderate and high myopia group was not significant. No significant correlation was found between the amounts of myopia and the postoperative CS (p>0.05). The area under the log contrast sensitivity function (AULCSF) showed no correlation with the total HOA (r2=-0.071, p=0.612, between the daytime AULCSF and the total HOA with a 4 mm entrance pupil, r2=-0.176, p=0.260, between the nighttime AULCSF and the total HOA with a 6 mm entrance pupil). There was no decrease in CS and glare after wavefront-guided LASIK for myopia. In conclusion, wavefront-guided LASIK based on the individual ablation patterns is a good option for refractive surgery to improve the visual quality in both moderate and high myopia cases.
Adult ; Comorbidity ; Female ; Humans ; Keratomileusis, Laser In Situ/*statistics and numerical data ; Korea/epidemiology ; Male ; Myopia/*diagnosis/epidemiology/*surgery ; Prognosis ; Recovery of Function ; Research Support, Non-U.S. Gov't ; Treatment Outcome ; Vision Disorders/*diagnosis/epidemiology/*prevention and control ; *Vision Tests ; *Visual Acuity