Chapter 8: Misinterpretation of visual fields |
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A B
Figure 8.18 Full-field ERG of both eyes in the above patient. (A) Under scotopic conditions there is moderate loss of b-wave amplitude in each eye. (B) Under photopic conditions, the b-wave amplitude in each eye is only mildly diminished.
dystrophy was confirmed by the results of her ERG. This patient’s history of nyctalopia and photopsias was also consistent with the diagnosis of photoreceptor disease.
Diagnosis: Rod-cone dystrophy
Tip: Bitemporal defects due to chiasmal compression preferentially involve the central field because macular fibers are affected early and most prominently. Defects demonstrating the opposite pattern, i.e. central sparing, should suggest a retinal disorder.
FURTHER READING
Visual field testing
D. R. Anderson, Perimetry, With and Without Automation, 2nd edn. St. Louis: Mosby, 1987.
D. R. Anderson, Automated Static Perimetry. St. Louis: Mosby, 1992.
D. O. Harrington, The Visual Fields. A Textbook and Atlas of Clinical Perimetry, 5th edn. St. Louis: Mosby, 1981.
Tilted disc syndrome
P. D. Brazitikos, A. B. Safran, F. Simona, M. Zulauf, Threshold perimetry in tilted disc syndrome. Arch Ophthalmol, 108 (1990), 1698–1700.
M. C. Brodsky, Congenital optic disk anomalies. Surv Ophthalmol, 39 (1994), 89–112.
L.Manfre,´ S. Vero, C. Focarelli-Baronne, R. Lagaua, Bitemporal pseudohemianopia related to the “tilted disk” syndrome: CT, MR, and funduscopic findings. AJNR Am J Neuroradiol, 20 (1999), 1750–1.
Dominant optic atrophy
D. Eliott, E. I. Traboulsi, I. H. Maumenee, Visual prognosis in autosomal dominant optic atrophy (Kjer type). Am J Ophthalmol, 115 (1993), 360–7.
C. S. Hoyt, Autosomal dominant optic atrophy. A spectrum of disability. Ophthalmology, 87 (1980), 245–51.
R. L. Johnston, M. J. Seller, J. T. Benham, M. A. Burdon, D. J. Spalton, Dominant optic atrophy: Refining the clinical diagnostic criteria in light of genetic linkage studies. Ophthalmology, 106 (1999), 123–8.