Occasionally a patient will present whose only symptom is decreased visual acuity. To determine whether the retina or optic nerve is the source of the problem, the multi-focal ERG and pattern VEP can be used for differential diagnosis. Abnormal multi-focal ERG amplitude indicates that the acuity loss is probably at the level of the retina.Unexplained Visual Acuity Loss
Because the VEP is an objective test of the visual system, it can be used to test patients who claim they cannot see but have no obvious pathology. A normal VEP, especially at small check sizes, is an indication that the optic pathways are functioning normally, at least to the level of the primary visual cortex. You should watch suspected malingerers carefully to make sure that they do not close their eyes or avert their gaze from the test pattern during the recording process.Malingering
Warning: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
Substance Tables:
The table below lists substances which may be contained within LKC’s RETeval and RETevet products. Substances listed as Type 1 are within permissible levels in one or more of LKC’s products. Substances listed as Type 2 are used in the production of some components used in LKC products and may be present at trace levels, but are typically destroyed during processing.
RETeval and RETevet Devices
| Substance | CAS # | Type | Listed as causing: |
| Nickel | 7440-02-0 | 1 | Cancer |
| Acrylonitrile | 107-13-1 | 2 | |
| Ethylbenzine | 100-41-4 | 2 | |
| Crystaline Silica | 14808-60-7 | 1 | |
| Lead | 7439-92-1 | 1 | Cancer Developmental Toxicity Male Reproductive Toxicity Female Reproductive Toxicity |
| Methylene Chloride | 75-09-2 | 2 | Cancer Female Reproductive Toxicity |
| Bisphenol A | 80-05-7 | 2 | |
| N-Hexane | 110-54-3 | 2 | Male Reproductive Toxicity |