Deviation of near vision is conveniently tested by
154. Ans. b (Madox wing test) (Ref. Parson Diseases of Eye, 19th/445; Khurana ophthalmology 3rd ed., 300, 311)The-deviation in near, vision is .conveniently tested by. the Maddox wing test, The patient looks through the two slit holes in the eyepieces of instrument. The fields exposed to each eye are separated bya adiaphragm in such a way that they glide tangentially into each other. The right eye sees a white arrow pointing vertically upowards and a red arrow poting to left, while the left eye sees a horizontal roq of figures in white and a vertical row in red. The arrow pointing to the horizontal row of figures and arrow pointing the vertical row should both be at zero; any deviation indicates an esso Or exophoria or a hyperphoria, the amount of which can be read on the scale.DIAGNOSIS OF HETEROPHORIA/LATENT STRABISMUS# Diagnosis of heterophoria/latent strabismus depends on the abolishing fusion so that, with its control, the eyes assume their position of rest.# Several Tests are Available for Assessing This:- Cover test- Madox rod test:# The rod is held in front of the eyes, image of highest point close to eye becomes dissimilar and fusion becomes dissociated.# Tests performance at 6 meter and 35 cm distance.- Maddox wing test (amount of phoria for near - at a distance of 33 cm) can be measured.- Prism vergence test- SynaoptophoreSwinging flash light test# It is performed when relative afferent pathway defect is suspected in one eye (unilateral optic nerve lesion with good vision).# To perform this test, a bright flashlight is shone on to one pupil and constriction is noted.# Then the flash light is quickly moved to swinging to and fro of flashlight is repeated several times while observing the papillary response.# Normally, both pupils constrict equally and the pupil to which light is transferred remains tightly constricted. In the presence of relative afferent pathway defect in one eye, the afferent pupil will dilate when the flash light is moved from the normal eye to the abnormal eye.# This response is called 'Marcus Gunn pupil' or a relative afferent papillary defect (RAPD).# It is the earliest indication of optic nerve disease even in the presence of normal visual acuity.Diplopia Charting# It is indicated in patients complaining of confusion or double vision. In it patient is asked to wear red and green diplopia charting glasses.# Red glass being in front of the right eye and green in front of the left.# Then in a semi-dark room he is shown a fine linear light from distance of 4 ft and asked to comment about the images in primary position and in other positions of gaze. Patient tells about the position and separation of the two images in different fields.Also know:Besides the actual measurement of the deviation in latent strabismus, the strength of the muscles involved should also be tested by forcing them to a maximum effort against prism - prism vergence tests.
Madox rod test
Madox wing test
Swinging flash light test
Diplopia chart test
Examination of the Eye