Binasal Visual Field Defects Caused by Temporal Posterior Subcapsular Cataracts

The first structures of the eye that light passes through are the refracting components; the cornea and lens. Therefore, it is possible, although not common, to have a visual field defect secondary to a corneal or lens opacity. Understanding where visual information reverses is crucial to attributing the defect to an anterior structure. Since the nodal point of the eye is at the posterior lens/anterior vitreous, an opacity anterior to this will cause an ipsilateral defect whereas it will be reversed at the nodal point. Although cataracts do not typically cause a visual field defect, there have been several case reports of defects secondary to posterior subcapsular cataracts (PSC) that resolve after surgery. We report a case supporting this finding.

Poster 15 Binasal Visual Field Defects Caused by Temporal Posterior Subcapsular Cataracts Kelsey Mileski1, Nancy Newman1, Valerie Biousse1 1 Emory Eye Center, Emory University School of Medicine, Atlanta, Georgia, USA Introduction: The first structures of the eye that light passes through are the refracting components; the cornea and lens. Therefore, it is possible, although not common, to have a visual field defect secondary to a corneal or lens opacity. Understanding where visual information reverses is crucial to attributing the defect to an anterior structure. Since the nodal point of the eye is at the posterior lens/anterior vitreous, an opacity anterior to this will cause an ipsilateral defect whereas it will be reversed at the nodal point. Although cataracts do not typically cause a visual field defect, there have been several case reports of defects secondary to posterior subcapsular cataracts (PSC) that resolve after surgery. We report a case supporting this finding. Description of Case(s): A 55-year old woman developed blurry vision nasally OU. Best corrected visual acuity was 20/30 OD and 20/40 OS with normal color vision and no RAPD. Slit lamp examination was remarkable for bilateral temporal PSC respecting the vertical meridian. Dilated fundus examination was unremarkable as was optic nerve OCT and ganglion cell analysis. 24-2 HVF demonstrated a general reduction in sensitivity with nasal depression OU. Following cataract surgery, her visual field defect resolved OU. Conclusions, including unique features of the case(s): A cataract often has a negligible effect on visual field, typically only affecting the total deviation. However, our patient and few other case reports support that a PSC can cause a visual field defect that resolves after cataract surgery. Such visual fields from PSC are classically opposite to the lesion location, similar to what we see in the optic nerve and retina, whereas lesions affecting the anterior portion of the lens, or the cornea will give a visual field defect ipsilateral to the lesion. This is explained by optics and the anatomic location of the nodal point in the eye. References: Karp CL, Fazio JR. Traumatic cataract presenting with unilateral nasal hemianopsia. J Cataract Refract Surg 1999; 25(9):1302-3 Harris WF. Nodes and nodal points and lines in eyes and other optical systems. Ophthalmic and Physiol Opt; 2010; 30(1):24-42 Rahman I, Nambiar A, Spencer AF. Unilateral nasal hemianopsia secondary to posterior sub capsular cataract. Br J of Ophthalmol 2003; 87(8):1045-1046 Keywords: Visual fields Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: [e-mail] 2020 Annual Meeting Syllabus | 73