Disorders• 2 SECTIONNerve Optic Congenital

Optic Pit

Key Facts

•Congenital excavation in the neuroretinal rim caused by absence of axons

•Nearly always associated with a corresponding steep-margined nerve fiber bundle visual field defect

•Serous retinal detachment and/or retinoschisis of the macula may occur

•Uncommonly associated with other developmental brain anomalies

Clinical Findings

•Inferotemporal round excavation in neuroretinal rim small enough to be overlooked

•Corresponding steep-margined nerve fiber bundle defect

•Sometimes serous detachment of macula

Ancillary Testing

•If fovea detachment present, optical coherence tomography shows subretinal fluid and retinoschisis

Differential Diagnosis

•Coloboma

•Glaucoma

Treatment

• If macular serous detachment is present, photocoagulation or vitrectomy

Prognosis

•Visual field loss is stationary

•Serous detachment is often difficult to treat

Fig. 2.6 Optic pit. Optic disc shows scalloped excavation inferotemporally, probably a forme fruste of coloboma.

Fig. 2.7 Serous retinal detachment (arrowheads) in a patient with an optic pit (arrow). (Courtesy of Mark W. Johnson, MD.)

Pit Optic

Disorders• 2 SECTIONNerve Optic Congenital

Morning Glory Optic Disc Anomaly

Key Facts

•Enlarged, totally excavated optic disc with:

•surface glial veils

•spoke-like retinal vessels emerging from its edge

•peripapillary retinochoroidal atrophy with pigment alteration

•Forebrain anomalies often present

Clinical Findings

•Staphyloma of posterior pole, excavation of an enlarged optic disc with surface glial veils, spoke-like retinal vessels emerging from its edge, and peripapillary retinochoroidal atrophy with pigment alteration

•Nearly always uniocular

•Visual function usually poor in affected eye

•Sometimes forebrain anomalies, including:

•basal encephalocele

•callosal dysgenesis

•hypoplastic intracranial carotid arteries with prominent basal cranial anastomoses (moya moya disease)

•hypopituitarism

Differential Diagnosis

•Optic disc coloboma

•Staphyloma

•Myopic degeneration

•Healed chorioretinitis

Ancillary Testing

•Brain imaging may disclose forebrain abnormalities

•Endocrine testing may disclose hypopituitarism, especially if there are forebrain abnormalities

Treatment

•Directed at associated findings

•Correction of hypopituitarism, especially low corticoid and growth hormones, is critical

Prognosis

• Visual deficit is usually severe but stable

Fig. 2.8 Morning glory optic disc anomaly, right eye. The optic disc is enlarged and excavated with radially exiting vessels, surface gliosis, and peripapillary atrophy.

Fig. 2.9 Midline brain malformations. Precontrast sagittal T1 MRI shows enlarged cisterna magna, hypoplastic cerebellar vermis, small optic chiasm, and malformed occipital lobes. The patient also had a tethered spinal cord. These are all midline dysgenetic abnormalities associated with morning glory optic disc anomaly.

Anomaly Disc Optic Glory Morning