Bagolini lenses have many narrow, parallel striations that, like Maddox rods, cause a point source of light to appear as a streak perpendicular to the striations. The lenses are usually placed with the striations at an angle of 135° (patient’s view) for the right eye and at an angle of 45° for the left eye, and the patient fixates on a distant light. Orthotropic patients will see 2 line segments crossing at their centers, forming an “X.” Figure 7-10 illustrates a range of possible subjective results. For a patient with monofixation syndrome and a central scotoma, 1 of the lines will be perceived as having a gap, corresponding to the scotoma.
Figure 7-10 Bagolini striated lens test for retinal correspondence and suppression. For these figures, the Bagolini lens striations are oriented at 135° in front of the right eye (patient’s view) and at 45° in front of the left eye, such that the patient sees a line segment at an angle of 45° with the right eye and a line segment at an angle of 135° with the left eye. The perception of the oblique lines seen by each eye under binocular conditions is shown. Examples of the types of strabismus in which these responses are commonly found are given.
Like Maddox rods, parallel Bagolini lenses can also assess torsion, but unlike Maddox rods, which are more dissociating, Bagolini lenses permit close-to-normal viewing and fusion and therefore reveal only manifest torsion; in addition, cover testing can be performed simultaneously.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.