Ординатура / Офтальмология / Английские материалы / Visual Fields Examination and Interpretation_Walsh_2011

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5-3-3 Recessive Optic Atrophy. This autosomal recessive somatic condition is the most uncommon form of inherited optic nerve disease. Unlike LHON and DOA, ROA is usually discovered in the first 3 to 4 years of life. It often presents as severe visual impairment, frequently associated with searching nystagmus. Visual acuity ranges between no light perception (NLP) to 20/400. There is diffuse optic disc atrophy, sometimes with attenuation of the retinal arterioles, similar to that seen in tapetoretinal degenerations. Hence, the differential diagnosis of ROA is more akin to that of retinal dystrophies than to other hereditary optic neuropathies. Electroretinography plays an important role in differentiating ROA from tapetoretinal degeneration, retinitis pigmentosa, or Leber’s congenital amaurosis, in that it is normal in ROA and severely impaired in the retinal degenerations.

The gene/chromosome for ROA remains to be identified. Not surprisingly there are several reports of consanguinity associated with this autosomal recessive condition.47-50

REFERENCES

1.Lambert SR, Hoyt CS, Narahara MH. Optic nerve hypoplasia. Surv Ophthalmol. 1987;32:1–9.

2.Brodsky MC. Congenital optic disc anomalies. Surv Ophthalmol. 1994;39:89–112.

3.Alvarez E, Wakakura M, Khan Z, et al. The disc-macula distance to disc diameter ratio: a new test for confirming optic nerve hypoplasia in young children J Pediatr Ophthalmol Strab. 1988;25:151–154.

4.Petersen RA, Walton DS. Optic nerve hypoplasia with good visual acuity and visual field defects: a study of children of diabetic mothers. Arch Ophthalmol. 1977;97: 254–258.

5.Williams J, Brodsky MC, Griebel M, et al. Septo-optic dysplasia: the clinical insignificance of an absent septum pellucidum. Dev Med Child Neurol. 1993;35:490–501.

6.Garcia-Filion P, Epport K, Nelson M, et al. Neuroradiographic, endocrinologic, and ophthalmic correlates of adverse developmental outcomes in children with optic nerve hypoplasia: a prospective study. Pediatrics. 2008;121:653–659.

7.Buchanan TA, Hoyt WF. Temporal visual field defects associated with nasal hypoplasia of the optic disc. Br J Ophthalmol. 1981;65:636–640.

8.Brodsky MC, Schroeder GT, Ford R. Superior segmental optic nerve hypoplasia in identical twins. J Clin Neuroophthalmol. 1993;13:152–154.

9.Borchert M, Garcia-Filion P. The syndrome of optic nerve hypoplasia. Curr Neurol Neurosci Rep. 2008;8:395–403.

10.Maumenee IH, Mitchell TN. Colobomatous malformations of the eye. Trans Am Ophthalmol Soc. 1990;88:123–135.

11.Irvine AR, Crawford JB, Sullivan JH. The pathogenesis of retinal detachment with morning glory disc and optic pit. Trans Am Ophthalmol Soc. 1986;84:280–292.

12.Brown GC, Shields JA, Goldberg RE. Congenital pits of the optic nerve head, II: clinical studies in humans. Ophthalmology. 1980;87:51–65.

13.Postel EA, Pulido JS, McNamara JA, et al. The etiology and treatment of macular detachment associated with optic nerve pits and related anomalies. Trans Am Ophthalmol Soc. 1998;96:73–93.

14.Graham MV and Wakefield GJ. Bitemporal visual field defects associated with anomalies of the optic discs. Br J Ophthalmol. 1973;57:307–314.

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194 Visual Fields

6-2 OPTIC NEURITIS

Optic neuritis is defined as a primary inflammation of the optic nerve. It is characterized by central visual loss that worsens over days and usually peaks about 1 to 2 weeks after the onset. It is usually unilateral but may be bilateral, especially in children, following viral infections like measles, mumps, and chickenpox. It occurs most commonly in adults (18-45 years old). Orbital or periocular pain may be present or precede the visual loss and is exacerbated with eye movements. Etiologies include demyelinating diseases/multiple sclerosis;, idiopathic, viral, or bacterial infections (syphilis); contiguous inflammation of the meninges, orbit, or sinuses,; granulomatous inflammation (tuberculosis, sarcoidosis, and cryptococosis); and autoimmune diseases. It is the most common cause of acute visual loss from optic nerve disease in the young and middle-aged adult group.

There is loss of color vision and perception of light intensity. Relative afferent pupilary defect (RAPD) is seen in unilateral or asymmetric cases. Uhtoff’s phenomena (visual deficit with exercise or increase in body temperature) may occur.

When it occurs in the intraocular portion of the optic nerve is termed papilitis or anterior optic neuritis, and some degree of disc swelling is seen with or without peripapillary hemorrhages. When the intraorbital part of the optic nerve is affected (majority of cases), it is termed retrobulbar or posterior optic neuritis and usually funduscopy is normal.1-4

Visual field findings include the following:

1.Central scotoma. This involves the central 5° to 20° surrounding fixation. Central scotoma usually indicates damage to the macular retinal ganglion cells [RGCs]or to the papillomacular nerve fibers at or within the optic nerve. If the scotoma incorporates the blind spot, the optic nerve is certainly involved.

2.Paracentral scotoma. This involves defects within 20° of the fovea.

3.Diffuse depression. There is generalized decreased visual sensitivity.5-8

Figure 6-1 shows central depression in a patient with optic neuritis.

The asymptomatic fellow eye may show some defect in up to one third of the cases.8

Magnetic resonance imaging (MRI) of the brain should be undertaken to look for signs of optic nerve enhancement (50-80%) and demyelination (up to 30%). An attack of monosymptomatic optic neuritis may precede the development of multiple sclerosis.

The natural history of the disease is for visual function to recover in a few weeks. In cases of profound visual loss or where the need for faster improvement is necessary, treatment with IV steroids is recommended (methylprednisolone 1 g/day for 3 days, followed by prednisone 1 mg/kg/day tapered over 11 days). In cases of positive findings on MRI (three or more T2 hyperintensities), the above protocol should be performed. Based on the Optic Neuritis Treatment Trial, it has been