Bagolini Lenses
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.
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.