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Show Journal of Neuro- Ophlhalmology 17( 3): 204- 206, 1997. © 1997 Lippincott- Raven Publishers, Philadelphia Unusual Scotomas After Transsphenoidal Surgery of a Pituitary Macroadenoma Helene Dollfus, M. D.,* Sophie Gomberg, M. D., f Philippe Touraine, M. D., t Christophe Orssaud, M. D.,* Mohamed Hamdani, M. D.,* Pascal Derome, M. D.,^ Frederique Kuttenn, M. D., f and Jean- Louis Dufier, M. D.* The case of a woman presenting unusual bilateral campimetric defects following transphenoidal surgery is presented. The defects, consisting of a necklace of small round scotomas, disappeared after a corticosteroid treatment. A postoperative inflammatory mechanism may explain these unusual visual field abnormalities. Key Words: Scotomas- Visual field- Transphenoidal surgery- Pituitary adenoma. Postoperative visual abnormalities are rare, but some have been reported after surgery for pituitary adenomas ( 1- 5). Most of these have been unilateral blindness or bitemporal visual field. We report the case of patient with a growth hormone ( GH)- secreting adenoma who underwent transsphenoidal surgery and developed unusual, late postoperative bilateral campimetric defects consisting of a necklace of small round scotomas, regularly and bilaterally displayed in the lower quadrants. To our knowledge, this visual field feature has not been previously reported. CASE REPORT A 30- year- old woman was referred to the Department of Endocrinology ( Hopital Necker- Enfants Malades, Paris) by her ophthalmologist in July 1995 with a suspected pituitary adenoma. For a few weeks, she had been complaining of a disturbance of vision in her right eye, without headache or nausea. She also reported enlargement of her fingers and feet as well as a change in her face for the previous 2 years. When she was first examined, the visual acuity was 20/ 30 in the right eye and Manuscript received December 1, 1996; accepted December 13, 1996. From the Departments of * Ophthalmology and fEndocrinology and Reproductive Medicine, Hopital Necker- Enfants Malades, Universite Paris V., Paris, France, and the ^ Department of Neurosurgery, Centre Medico- Chirurgical Foch, Suresnes, France. Address correspondence and reprint requests to Dr. Helene Dollfus, Department of Ophthalmology, Hopital Necker- Enfants Malades, 149 Rue de Sevres, 75015 Paris, France. 20/ 20 in the left. Results of slit- lamp examination were normal. The fundi were normal. The right visual field was normal, but a defect was noted in the left, 25° from the fixation point, in the lower temporal field, near the vertical meridian ( Fig. 2A). A computed tomography scan displayed a 30 x 20 mm pituitary adenoma invading the left cavernous sinus with compression of the visual tract. The diagnosis of acromegaly was made and was confirmed by the increased GH level ( 67 ng/ mL; normal < 5 ng/ mL) and of insulin growth factor ( 1305 ng/ mL; normal < 260 ng/ mL). Prolactin also was found to be increased ( 55 ng/ mL; normal < 20 ng/ mL). To reduce the volume of this adenoma before surgery, the patient received a combination of a dopaminergic agonist ( oral bromocriptin) and a somatostatin agonist ( Octreotide then Lanreotide). At the end of September 1995, although the plasma GH level had decreased ( 35 ng/ mL), the tumor remained unchanged as noted by magnetic resonance ( MR) imaging ( 6) ( Fig. 1A). In addition, the right visual field now showed changes, with the development of a defect in the lower temporal II/ l and III/ l isopters. Transsphenoidal surgery was performed, and the adenoma was incompletely removed because of the left cavernous sinus invasion. But the visual tract certainly was decompressed since the sellar diaphragm was noted to be sinking into the sella. The pathologic report was of a GH- secreting pituitary adenoma. Seven days after the surgery, the patient was referred back because of further deterioration of her vision. The visual acuity was still 20/ 20, and the fundi remained unchanged. However, two round scotomas, nearly 10° in diameter, were detected in the lower right temporal visual field ( Fig. 2B). The left visual field was unchanged. The visual fields were worse 6 days later ( Fig. 2C). In the right visual field, five scotomas were displayed like a necklace, except for the scotoma in the lower temporal quadrant, between 20° and 50° from the fixation point. The remaining scotoma was in the lower nasal quadrant. Two identical scotomas also were observed in the lower nasal and in the left temporal field, 30° from the vertical meridian. The MR imaging study did not reveal any ab- 204 SCOTOMAS AFTER TRANSSPHENOIDAL SURGERY 205 FIG. 1. A: Preoperative MR imaging of the adenoma compressing the visual pathways ( arrow). B: Postoperative MR imaging showing absence of hemorrhage or of a compressing mass on the visual pathways [ arrow). FIG. 2. Visual fields ( A) before transsphenoidal surgery; ( B) 7 days after surgery with scotomas appearing in the lower fields; ( C) 9 days after surgery showing the scotomas with a " necklace" pattern; and ( D) after steroid treatment showing total recovery. J Neuro- Oplilluiliiiol, Vol. 17, No. J, 1997 206 H. DOLLFUS ET AL. normality such as hemorrhage or arachnoiditis ( Fig. IB). The patient received three bolus doses of methylprednis-olone ( 50 mg per day intravenously) followed by prednisolone ( 60 mg per day for a week). The visual fields became normal within 4 days of this treatment and have remained unchanged during a follow- up of 8 months ( Fig. 2D). DISCUSSION The complication of visual field defects after pituitary surgery has been reported, most defects being well defined and consisting of quadrantanopsia, hemianopia, or unilateral blindness. Such complications result from direct damage of the visual tract during the surgery, from a postoperative hemorrhage ( 1- 5), or from inappropriate exogenous packing ( 7). Operative trauma or postoperative edema may be responsible for ischemia resulting in visual defects. Although the transsphenoidal surgery for GH-secreting macroadenoma was uneventful, providing decompression of the visual pathways, the patient reported here developed unusual late campimetric scotomatous defects. These were atypical because of their late onset, shape, localization, and their rapid regression with steroid therapy. The etiology of the scotomas reported here remains unclear. The late onset rules out immediate operative neural damage. The postoperative MR imaging excluded a delayed hemorrhage. On the contrary, the late onset and the rapid evolution of the visual field defects favors an inflammatory mechanism. In addition, the topography and the campimetric aspect of the scotomas could result from a localized fascicular ischemia of the optic tract. The vascularization of the intracranial part of the optic nerve and of the chiasma is fragile and is supported only by vasavasorum from the dura mater. Postoperative inflammation of the meninges probably induced subtle arachnoiditis undetectable by MR imaging and was responsible for compression of the fragile vessels supplying the optic tract. Thus, the antiinflammatory treatment was efficient for the presumed arachnoiditis with total recovery of the visual field. Acknowledgment: We thank Phillip Harris, FRCSE, FRCPE, FRCS ( Glas), FRSE, of Edinburgh for his help. REFERENCES 1. Trautmann JC, Laws E. Visual status after transsphenoidal surgery at the Mayo Clinic, 1971- 1982. Am J Ophthalmol 1983; 96: 200- 8. 2. Cohen AR, Cooper PR, Kupersmith MJ, Flamm ES, Ransohoff J. Visual recovery after transsphenoidal removal of pituitary adenomas. Neurosurgery 1985; 17: 446- 52. 3. Black PM, Zervas NT, Candia GL. Incidence and management of complications of transsphenoidal operation for pituitary adenomas. Neurosurgery 1987; 20: 920^ 1. 4. Barrow DL, Tindall GT. Loss of vision after transsphenoidal surgery. Neurosurgery 1990; 27: 60- 8. 5. Peter M, De Tribolet N. Visual outcome after transsphenoidal surgery for pituitary adenomas. Br J Neurosurg 1995; 9: 151- 7. 6. Slavin ML, Lam BL, Decker RE, et al. Chiasmal compression from fat packing after transsphenoidal resection of intrasellar tumor in two patients. Am J Ophthalmol 1993; 115: 368- 71. 7. Arita K, Yano T, Sumida M, Hibino H, Yonezawa M. MRI visualization of complete bilateral optic nerve involvement by pituitary adenoma: a case report. Neuroradiology 1993; 35: 549- 50. ./ Neum- Ophthalmol, Vol. 17, No. 3, 1997 |
