| Subject |
Adult; Eye Abnormalities, diagnosis; Eye Abnormalities, physiopathology; Female; Humans; Magnetic Resonance Imaging, methods; Magnetic Resonance Imaging, standards; Optic Disk, abnormalities; Optic Disk, pathology; Optic Disk, physiopathology; Optic Nerve, abnormalities; Optic Nerve, pathology; Optic Nerve, physiopathology; Optic Nerve Diseases, diagnosis; Optic Nerve Diseases, physiopathology; Predictive Value of Tests; Retinal Artery, abnormalities; Retinal Artery, pathology; Vision Disorders, diagnosis; Vision Disorders, etiology; Vision Disorders, physiopathology |
| OCR Text |
Show PHOTO ESSAY Tilted Optic Discs Visualized by Magnetic Resonance Imaging Michelle E. Tarver- Carr, MD, PhD and Neil R. Miller, MD FIG. 1. A. The right optic disc is slightly small and oval with mild blurring of its temporal margin. The left optic disc shows more obvious blurring of its nasal margin. B. Automated static perimetry ( Humphrey, SITA standard 24- 2) shows non-localizing visual field defects in both eyes. Mean deviations were - 3.31 dB in the right eye and - 6.29 dB in the left eye. C. Precontrast T1 ( left) and T2 ( right) MRIs demonstrate oblique insertion of the optic nerve into the left globe ( arrows) and posterior nasal flattening of the left globe ( arrowheads). 282 J Neuro- Ophthalmol, Vol. 26, No. 4, 2006 Tilted Optical Discs and MRI J Neuro- Ophthalmol, Vol. 26, No. 4, 2006 Abstract: A young woman with headaches displayed ophthalmoscopic features suggestive of papilledema. MRI showed no intracranial abnormalities but demonstrated oblique insertion of the optic nerve into the left globe and posterior nasal flattening of the left globe, features consistent with congenitally tilted optic discs. This is the second report to show that orbital MRI can demonstrate this phenomenon. (/ Neuro- Ophthalmol 2006; 26: 282- 283) A28- year- old non- obese woman presented to her optometrist complaining of right temporal headaches that had been present for the last year. The headaches occurred primarily in the morning upon awakening and were not associated with nausea, vomiting, or other neurologic symptoms. The optometrist found a refractive error of - 5.25 + 0.25 X 11° in the right eye and - 6.50 + 0.50 X 134° in the left eye. On ophthalmoscopic examination, the optometrist and, later, an ophthalmologist found elevated optic discs and queried the possibility of papilledema ( Fig. 1A). MRI was interpreted as being normal. On examination at the Wilmer Eye Institute, best-corrected visual acuities were 20/ 20 in both eyes, with normal color perception and field defects that did not respect the vertical midline ( Fig. IB). The pupils reacted normally to light stimulation; there was no relative afferent pupillary defect. The right optic disc appeared to be slightly tilted but was otherwise normal in appearance. The left optic disc was substantially tilted with oblique entry of retinal vessels. MRI ( Fig. 1C) revealed flattening of the nasal aspect of the left globe and oblique entry of the left optic nerve. The right optic nerve showed similar but much less impressive changes. These findings were consistent with a clinical diagnosis of congenitally tilted optic discs. The tilted disc syndrome is a bilateral congenital anomaly of the optic nerve head observed in 1.6% of the population ( 1). Common findings are oblique direction of the retinal vessels, moderate- to- high myopia, astigmatism, and temporal visual field defects that do not respect the vertical midline ( 2,3). Although there have been many descriptions of the syndrome, little imaging evidence demonstrating the oblique entry of the nerve into the globe exists. Singh ( 4) showed abnormalities on A- scan ultrasonography of tilted optic discs correlating with an increase in the nerve diameter and doubling of the optic nerve shadow on B- scan echography. As in our patient, Manfre et al ( 5) showed on MRI bilateral oblique insertion of the optic nerve with flattening of the both globes. REFERENCES 1. Vongphanit J, Mitchell P, Wang JJ. Population prevalence of tilted optic disks and the relationship of this sign to refractive error. Am J Ophthalmol 2002; 133: 679- 85. 2. Dorrell D. The tilted disc. Br J Ophthalmol 1978; 62: 16- 20. 3. Giirlii VP, Alimgil ML, Benian O. Topographical analysis of the visual field in tilted disk syndrome. Retina 2002; 22: 366- 68. 4. Singh J. Echographic features of tilted optic disk. Ann Ophthalmol 1985; 17: 382- 84. 5. Manfre L, Vero S, Focarelli- Barone C, et al. Bitemporal pseudohe-mianopia related to the " tilted disk" syndrome: CT, MR, and fundoscopic findings. AJNR Am JNeuroradiol 1999; 20: 1750- 1. Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland. Address correspondence to Dr. Neil R. Miller, Johns Hopkins University School of Medicine, Department of Ophthalmology, 600 N. Wolfe St., Maumenee 127, Baltimore, MD 21287; E- mail: nrmiller@ jhmi. edu 283 |
