Perimetry Test or "Visual Field Testing" is considered a very useful test to assess the optic nerves function. It is a subjective test requiring the patient's full cooperation to provide a correct and accurate test. Hence with a reliable test, the functional status of optic nerve is determined.
If your ophthalmologist has recommended this test, it means that he suspects optical nerve disorders; this could be due to eye or neurological problems that the most important and most common of them are: increased intraocular pressure "glaucoma " , space-occupying lesions within the optic canal , a rise in pressure of the cerebrospinal fluid , and optic nerve head inflammation.
However, this test is performed regularly - generally every six months- in patients taking "hydroxychloroquine" for the treatment of rheumatoid arthritis or lupus, especially in terms of the possibility of sedimentation of chloroquine on the retina.
Fereshteh Shariati, Ophthalmologist