The Lancaster Test is a diagnostic procedure used by ophthalmologists to identify which muscles in the eye structure are weakened or paralyzed.
Carrying out this test makes it possible to diagnose the squint, ocular paralysis, nerve damage and the causes of a diplopia or double vision.
The Hess Lancaster Test is a very simple procedure and does not pose any risk to the patient.
En Área Oftalmológica Avanzada We explain below what the Lancaster Test consists of and what it is for.
What is the Lancaster Test?
The Lancaster Test is a test performed in ophthalmology to study the state of eye motor with respect to the other in different positions of the look.
This test allows to examine deviations, in patients with diplopia, because of squint, paralysis or nerve damage.
The mobility of the eye is possible thanks to the six muscles that make up the ocular structure. Through the Hess Lancaster Test, the ophthalmologist can find out which of these muscles is affected and to what degree.
The Lancaster Test evaluates the motor responses of the eye that is not fixing correctly due to the cause presented by the patient, which is why this test is essential to determine the origin of a double vision.
How it is performed?
The Lancaster Test is a completely painless procedure that does not pose any risk to the patient.
The examination is performed in the ophthalmologist's office, does not require prior preparation or dilation of the pupil and has an estimated duration of 10 minutes.
To perform the exam, the patient must sit in a chair with their back straight, their eyes must be at the same height as the center of the screen and they will have to put on glasses with a green lens in one eye and red in the other.
The patient, located one meter away from the Hess screen, must position the light of the flashlight in his hand on the light of the flashlight projected by the examiner. That is, he must indicate to the doctor, by means of the flashlight, where he sees on the screen, the light projected by the specialist.
During the performance of the Lancaster Test, the ophthalmologist will ask the patient to look at different positions on the Hess-Lancaster screen to examine the mobility of the muscles and the deviations present.
It is important for the ophthalmologist to ensure that the patient only moves his eyes and not his head, since otherwise errors may appear in the test.
When a patient presents very important deviations, he projects the light of his flashlight far from the one projected by the examiner, even going so far as to project it outside the Hess screen.
In which cases is it recommended to do the Hess-Lancaster test?
The Hess-Lancaster test is indicated whenever the patient presents diplopia without an apparent cause.
It is also necessary to perform this test to study strabismus, nerve injuries, eye palsies y vision problems due to hyperthyroidism.
Do you have any questions about the Hess-Lancaster test? In Área Oftalmológica Avanzada We have the best teams of ophthalmologists in Barcelona ready to answer all your questions. We will be happy to assist you!
