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Show Journal of Nnuo- Ophlhalmology 17( 1): 53- 56, 1997. © 1997 I. ippincoll- Raven Publishers, Philadelphia Feature Photo A Descent Thing to Do For the Chiasm Gregory S. Kosmorsky, D. o., and Jeanette M. Straga, D. o. CASE HISTORY A 64- year- old woman was found to have a visual field defect. Her visual acuities were 20/ 30 and 20/ 20. On magnetic resonance imaging ( MRI) a large suprasellar lesion with a cystic component was found. She had panhypopituitarism, and replacement therapy was instituted. A stereotactic biopsy with placement of an Omaya reservoir was performed on 8/ 13/ 92, and no definitive diagnosis could be made. The patient underwent periodic evacuations of fluid from the cystic lesion as an outpatient. On 11/ 24/ 92, she underwent a frontotemporal craniotomy with marsupialization of a suprasellar arachnoid cyst. Her first visual field test performed on a Goldmann perimeter ( GVF) at the Cleveland Clinic on 11/ 27/ 92 showed a partial temporal defect in the right eye and a normal left eye. A GVF field test on 6/ 13/ 93 showed a large temporal defect in the right eye and a large blind spot in the left eye. A static field taken on a Humphrey perimeter on 12/ 29/ 93 found a complete bitemporal defect with an average decibel loss of - 13 db ( Fig. 1). Manuscript received June 24, 1996; accepted July 4, 1996. From the Division of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio 44195. Address correspondence and reprint requests to Dr. Gregory S. Kosmorsky, Division ol'Ophthalmology, A- 31 Cleveland Clinic Foundation, I Clinic Center Drive, Cleveland, OH 44195- 5024. An ophthalmologic examination on 4/ 27/ 94 found that her vision was 20/ 50 and 20/ 20 with a 1+ RAPD ( relative afferent pupillary defect) OD. Her cup/ disc was 0.9 and 0.7 with pallor of the remaining rims. A bitemporal defect with an average loss of - 16 db was present. She returned on 7/ 28/ 94 with visual acuities of 20/ 200 OU. Her HVFs had undergone an average loss o f - 2 0 db ( Fig. 2). MRI on 8/ 11/ 94 showed that the chiasm was upwardly displaced by the cystic lesion ( Fig. 3). She underwent a ventriculojugular shunt procedure on 9/ 6/ 94, and the next day her vision had worsened to 8/ 200 OD and a vague 20/ 400 OS. MRI found a gross prolapse of the chiasm into a large empty sella ( Fig. 4). The catheter was immediately tied off, and the patient made a slow recovery, achieving visions of 20/ 200 and 20/ 40 by I 1/ 7/ 94. MRI demonstrated return of the chiasm to its premorbid position. Visual acuity improved to 20/ 60 OD and 20/ 20 OS by 10/ 23/ 95, and she was left with a bitemporal defect ( Fig. 5). The syndrome of chiasmal prolapse into an empty sella is a well- described phenomenon. Most patients have undergone surgery and/ or radiation that leads to downward displacement with resultant acuity and field loss. This case is unique in that an overdrainage of cerebrospinal fluid by a shunt tube resulted in the downward displacement. Furthermore, clamping of the shunt allowed the chiasm to rise into its normal position, resulting in a dramatic return of vision. 53 54 G. S. KOSMORSKY AND J. M. STRAGA FIG. 1. Complete bitemporal visual field defect. 4 ( 0 \{ ( 13) KB) ( 2?) ( 19) ( 13)(( 25 ( 25) 27 11 ((( 27 .25 29 1( 1 28 29 29 38 29 1( 1 ( 26) ( 29) ( 27) ( 29) 1( 1 26 25 ( 25) 18 25 26 113 ( 18) < B ( 0 ( 8 KB) (( 0) 13 11 ( 13) ( ( 0 ( 0 -<( 0>+- K0)-( 16 ( 0 19 ( 22) 1 ( 0 ( 4) KB) - KB)-( ( 0 KB) < 0 KB) 14 6 ( 0) 7 13)- ( 0 12 0 3) 12 14 ( 14) 13 ( 22) ( 0 -(< 0>- ( 0 « 0 ) 22 ( 0) 1 ( 7) 11 15 ( 0 KB) 2 ( 0) 4 - ( B ) - < B KB) 8 IB 5 • 19 22 24 23 25 ( B) 24 23 21 25 ( 25) 22 ( 22) 25 ( 25) 28 1 24 25 ( 31) 28 29 6 ( 15) 23 27 29 26 27 ( 27) 26 ( 29) 2t 29 29 21 1 23 ( 21) 23 16 20) 2B ^ 22 24 12 ( 2) 22 27 26 22 14 ( 2B) ( 0 0 KB) 27 ( 25) 26 29 ( 27) 25 ( 23) 19 18 ( 0 ( 0 KB) 15 KB) 23 28 ( 28) 27 30 ( 22) 19 ^ B ( B ( 0 ( B ( 0 < 0) < B ( 0 < B ( B ( B KB) < B (( B) ( 0 ( fl ( 0 KB) ( 0 0 ( 0 ( B ( B < B ( 0 ( 0 « 0) < B 1 1 ( 0 ( 0 ( 0 1 ' I ( 0 ( 0 ( 0 KB) ( 0 K0) ( 0 - K B ) - < B ( 0 < B KB) ( 0 ( 0 KB) IS (/) ( 91 - K Hl-di ( B (( B) ( 0 ( 0 ( 0 fl ( 6) ( 0 5 (( B)( 5) ( 0 l21 K0H15) ( 0 15 - ( ( 0 ) ( 3 ) - ( 0 | 0 KB) ( 0) ( fl I9 B) ? ( 0 ?? • 3 6) 1 11 ( 15) 17 ( 2/) ?? , -( 2?) f 1/ ( 13) ? 3 ( 23) 19 20 1? ( IB) 26 ? 7 a •>? 1? ( 14) ? 4 - A- 14 ( 14) 14 ( 12) 17 -(? 1) 12 FIG. 2. Worsening of the bitemporal visual field defect. ./ Neuro- Opluhalmol, Vol. 17, No. /, 1997 A DESCENT THING TO DO FOR THE CHIASM 55 • FIG. 3. Coronal MRI scan showing upward dis-j placement of the optic chiasm by a sellar region cyst. Fid. 4. Coronal' ana' saggi'tai iviRi's snowing severe downward herniation of the optic chiasm after shunt placement with drainage of the cystic fluid collection. J Newo- Ophllmlmol, Vol. 17, No. I. 1997 56 G. S. KOSMORSKY AND J. M. STRAGA t i i~ y. .' » Jr> 5 .' > #*~* 3*', S " '" T : I S I * *^ FIG. 5. Persistent bitemporal visual field defect after clamping of the tube shunt. ./ Nniro- Oplilhalmol. Vol. 17. No. I. 1997 |
