The Importance of Visual Field Test ( Perimetry)
A Perimetry or Visual Field Test is a very useful test to evaluate the function of the optic nerve (cranial nerve II). This test is a kind of subjective test, in which patient's cooperstion is important factor in accuracy of the test. So the function and condition of the optic nerve are studied and determined by an accurate and reliable test.
If your optometrist or ophthalmologist recommends Perimetry for you, it means that he/she suspects you have optic nerve disorder; this may be due to ocular or neurologic disorders which the most important and common of them are elevated intraocular pressure, "Black water or Glaucoma", lesions of the optic pathway, increased intracranial pressure (increased cerebrospinal fluid pressure) and optic neuritis ( inflammation of The optic nerve).
Since long-term therapy with chloroquine can lead to irreversible retinal damage, The patients who take "hydroxychloroquine" for rheumatic disease or lupus, should do this test regularly at intervals of six months; because of retinal deposition of chloroquine.