A 27-year-old man sought further neurologic evaluation for longstanding muscle weakness previously diagnosed as limb girdle muscular dystrophy. His mother and two siblings had the same condition. His mother also had insulin-dependent diabetes mellitus. The patient had no visual symptoms.
Neurologic examination demonstrated moderate proximal weakness and muscle atrophy. In addition, confrontation visual field testing suggested inferior visual field loss binocularly and prompted neuro-ophthalmic consultation. Neuro-ophthalmic examination demonstrated uncorrected visual acuities of 20/20 in OU with normal color vision and pupillary responses. Ophthalmoscopy disclosed superior hypoplasia of the optic discs with a partial double-ring sign (Fig. 1A and B). Goldmann perimetry (Fig. 2) disclosed bilateral inferior altitudinal defects.
Partial optic nerve hypoplasia in the offspring of insulin-dependent diabetic mothers was first described by Peterson and Walton in 1977 (1). The fundus and visual field findings in this syndrome were more fully characterized by Nelson et al. (2), and the term superior segmental optic hypoplasia was subsequently introduced by Kim et al. (3). While initially considered to be a rare anomaly, a study of 34 offspring of diabetic mothers by Landau et al. (4) found a prevalence of 8.8%. The condition is usually bilateral, affects females more often than males, and is unassociated with other developmental anomalies. Individuals with this condition are typically asymptomatic, with the field defect discovered during routine testing, as in our patient. This form of optic disc anomaly is occasionally seen in patients who do not have a history of maternal diabetes (5). Awareness of this distinctive fundus appearance can spare the patient the time and expense of unnecessary ancillary testing.
1. Peterson RA, Walton DS. Optic nerve hypoplasia with good visual acuity and visual field defects: a study of children of diabetic mothers. Arch Ophthalmol 1997; 95:254–8.
2. Nelson M, Lessell S, Sadun AA. Optic nerve hypoplasia and maternal diabetes mellitus. Arch Neurol 1986; 43:20–5.
3. Kim RY, Hoyt WF, Lessell S, et al. Superior segmental optic hypoplasia: a sign of maternal diabetes. Arch Ophthalmol 1989; 107:1312–5.
4. Landau K, Bajka JD, Kirchschlager BM. Topless optic disks in children of mothers with type I diabetes mellitus. Am J Ophthalmol 1998; 125:605–11.
5. Hashimoto M, Ohtsuka K, Nakagawa T, et al. Topless optic disk syndrome without maternal diabetes mellitus. Am J Ophthalmol 1999; 128:111–2.