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Progressive visual loss. What type of mass lesion?
SURVEY OF OPHTHALMOLOGY
VOLUME 28.
NUMBER 1 . JULY-AUGUST
1983
CLINICAL CHALLENGES RONALD M. BURDE AND PAUL HENKIND, EDITORS
Progressive Visual Loss. What Type of Mass Lesion? NEIL R. MILLER,
M.D.
Comments by John L. Keltner, M.D., John W. Gittinger, Jr., M.D., and Ronald M. Burde, M.D. The Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, Maryland
(In keeping with thepurposes of a Clinical Pathological Conference, the abstract and kty words appear at the end of the article.)
A
performed that showed a generalized enlargement of the left posterior orbital optic nerve. No intracranial abnormalities were noted. Hypocycloidal polytomography suggested hyperostosis of the left optic canal.
43-year-old, previously healthy woman noted mild, painless, blurred vision in her left eye only. After this had persisted for several months she sak her ophthalmologist who noted left optic disc swelling and referred her for further evaluation. On examination, the visual acuity in the right eye was 20/l 5 at distance and J 1 at near. Visual acuity in the left eye was 20125 at distance and J2 at near. Color vision was normal in the right eye and slightly diminished in the left eye. The right visual field was full; the left visual field showed slight constriction. There was a left afferent pupillary defect. There was 2 mm of left exophthalmos. Ocular motility was normal. Ophthalmoscopy showed a normal right fundus. The left optic disc showed moderate swelling. What is your diagnosis? What is your management? Wouldyou changeyour management ifthe visual acuity were 20/400 or the visualJield were significantly constricted? A diagnosis of presumed compressive optic neuropathy was made, and computed tomography was
Comments Comments by John L. Keltner, M.D., Departments of Ophthalmology, Neurology, and Neurosurgery, Universi4 of California at Davis, Davis, Calfornia. Dr. Miller has described a case of a 43-year-old woman with minimal visual loss, constriction of her visual field, an afferent pupillary defect, and swelling of the left optic nerve. This constellation of signs and symptoms combined with the computerized axial tomography (CAT) scan showing abnormalities and hyperostosis of the left optic canal is fairly diagnostic of a primary optic nerve sheath meningioma. No mention is made about whether the patient has other signs of neurofibromatosis, but certainly “cafe au lait” spots and Lisch nodules on the 45
46
Surv Ophthalmol
28 (1) July-August
1983
iris, as well as a family history of neurofibromatosis, should be investigated. This patient did not demonstrate optociliary shunt vessels; however, progressive loss of vision, optic disc pallor and optociliary shunts constitute the clinical triad of optic nerve sheath meningiomas.6.20,2’ 0 P tociliary shunt vessels may also be seen following central retinal vein occlusions and, less commonly, they occur as a sequela of a variety of other conditions. Shunt vessels seen with optic nerve sheath meningiomas fill early in the arteriovenous phase of fluorescein angiography, and the flow drains to the central vein tributaries later in the angiogram and is hyperfluorescent to the other veins. In the central vein occlusion group, the shunt fills later in the venous phase.2l5 Before the introduction of CAT scanning, optic nerve sheath meningiomas often went undiagnosed or were misdiagnosed as “chronic optic neuritis.” Orbital venography, orbital x-ray and orbital exploration were the only diagnostic methods available until the advent of ultrasound and CAT scanning. Ultrasound generally has been difficult with posteriorly placed lesions such as the one described in this particular case. In general, ultrasound will provide a better tissue diagnosis in lesions that can be reached by this modality than will CAT scan in its present state of development. However, the recent development of nuclear magnetic resonance (NMR) scans will likely replace ultrasound and CAT scan as the best method for diagnosing and defining the histologic character of orbital lesions.‘,’ Two other techniques used in orbital diagnosis are orbital endoscopy and needle aspiration biopsy. Although neither of these techniques would probably be necessary in the present case, they should be mentioned. Over the last several years, Dr. John Norris at Pacific Medical Center in San Francisco has developed the technique of orbital endoscopy and has performed over 60 endoscopic procedures on the orbit.‘s’8 He has performed four biopsies through his endoscope and even has opened up one optic nerve sheath by orbital endoscopy on a child with an optic nerve glioma. In addition, Dr. Norris recently made a tissue diagnosis of mucormycosis by the endoscopic route. Another diagnostic technique used in the orbit is fine needle aspiration biopsy guided by CAT scan.“*‘2 While this technique has been successful in certain cases, it requires a good pathologist who is able to draw diagnostic conclusions from the cytologic preparations. In addition, it is more difficult to obtain adequate material if the lesion is both solid and cohesive. This procedure obviously is also not without risk, particularly in the hands of inexperienced surgeons, since there are many structures in
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ET AL
and around the orbit which might produce serious problems if inadvertently punctured. Finally, with the advent of computerized axial tomography and ultrasound, orbital exploration as a method for diagnosing tumors rarely has been needed in most cases. Now, with the introduction of nuclear magnetic resonance scanning and the possibility of orbital endoscopy becoming a more widely accepted technique, orbital exploration for biopsy probably will be performed very infrequently. The management of this patient, I believe, at the present time should be conservative.‘~‘3~24 Wright and associates2* and Alper’ recently have reviewed two large series of patients with primary optic nerve sheath meningiomas. Alper has differentiated these into patients under the age of 20, a group between ages 20 and 35, and those older than 35.’ The optic nerve sheath meningioma in a patient under age 20 appears to be especially aggressive and life-threatening. In the group between ages 20 and 35, the disease becomes less aggressive but still potentially life-threatening. In the group over age 35, the disease tends to be more indolent in its growth pattern. In the 20 to 35 age group, Alper recommends that once vision is lost an orbital operation should be performed with removal of the optic nerve and the If the tumor has escaped from the meningioma. dural sheath, he recommends a craniotomy and removal of the intracranial portion of the tumor. In the group over age 35, Alper recommends CAT scanning every six months with close clinical evaluation by visual fields and visual acuity, and if vision is lost in the eye, he recommends removal of the tumor. Wright and associates 24also report that the tumor should be removed once useful vision is gone. If the eye is blind, removal of all of the meningioma prevents growth of the tumor within the orbit or along the optic canal in the brain. If useful vision remains, incising the dura mater will relieve the pressure of the tumor; however, the results have been disappointing and all of the patients on whom Wright and his colleagues have performed this procedure have ended up with vision being destroyed within 18 months. In general, Wright and associates and Alper believe appropriate management is to wait for vision to deteriorate and then excise the optic nerve together with the meningioma. The exceptions to this would be: (1) if the growth rate of the tumor suggests a malignant-type of meningioma, the tumor should be biopsied; and (2) if a high resolution CAT scan shows a very small anterior tumor and useful vision remains, the nerve should be explored in an attempt to see whether the tumor can be removed without destroying vision. While several cases have been reported of SUC-
PROGRESSIVE
VISUAL
LOSS
cessful removal of primary optic nerve sheath meningiomas, 4,14.1gtheir successful removal and preservation of vision have been rare. The reason for this would appear to be that the vascular supply of the optic nerve is compromised by any dissection necessary to remove the meningioma from the optic nerve. Radiation therapy for optic nerve sheath meningiomas has been suggested by Smith and colleagues. I9 They cite one patient whose vision had deteriorated to hand motions and after 5220 rads of radiation therapy recovered to 20/70 for 18 months; however, the fields subsequently deteriorated, and there was no followup reported after 42 months. Others have reported radiation therapy for intracranial meningiomas with variable results. In general, radiation therapy has been reserved for histologically malignant or clinically invasive meningiomas. In this particular patient, because of her age, I believe a conservative approach should be undertaken, waiting until vision falls to less than 20/400. At that time, if the patient understands the risks and benefits of the surgical procedure involved, I believe a surgical removal may be in order. Until we have more information on the effects of radiation on this type of tumor, both long- and short-term, I would be reluctant to treat this patient with radiation therapy. If the patient refused to follow this recommendation, I believe that an equally cogent argument could be made for following this patient without intervention. Serial CAT scans certainly could be used to identify any intracranial spread of this tumor. Even though there will be some tumors that will invade intracranially and be missed by CAT scan, high resolution scanners will be able to detect most significant intracranial involvement. If the tumor expands rapidly in the orbit with loss of vision, this might push the surgeon to consider surgical removal once the eye is blind rather than continuing with conservative management. There is no question that we need more information not only about the natural history ofoptic nerve sheath meningiomas but also about the appropriate treatment modalities. Hopefully, a multicenter combined series could answer these types of questions, and I believe there is a strong need for this type of study.
Comments by John W. Gittinger, Jr., M.D., Division of Ophthalmology, University of Massachusetts, Worcester, Massachusetts In this middle-aged woman with disc swelling, an afferent pupillary defect, and unilateral visual dysfunction, enlargement of the optic nerve on computerized tomography is virtually diagnostic of primary
47
optic nerve sheath meningioma. The combination of disc swelling and optic nerve enlargement is also seen with optic nerve gliomas, but this is a tumor of children and young adults, and the enlargement is characteristically fusiform. Also, optic nerve gliomas expand the optic foramen but do not induce hyperostosis. The development of computerized tomography has greatly facilitated the detection of primary optic nerve sheath meningiomas, but in spite of the resolution of the newer generation scanners it is not always an easy diagnosis to make.” In this patient, when a tumor was found at the time of surgical exploration, excisional biopsy was the obvious approach. However, now that the diagnosis can be made with confidence by a simple, noninvasive study, the question of management is more difficult. Surgical removal of primary optic nerve sheath meningiomas is complicated by the arrangement of the vascular supply of the optic nerve. In the optic canal the ophthalmic artery lies within the subarachnoid space; it then becomes extradural and sends branches through the meninges to supply the retrolaminar nerve. Meningiomas arise from the arachnoid, and the intimate relationship between the meninges and optic nerve vascular supply assures that the tumor’s vascular supply and that of the adjacent optic nerve are interdependent. Removal of the tumor thus results in blindness of the ipsilateral eye. Rarely, when the tumor is discrete (or perhaps does not arise directly from the meninges themselves), meningiomas have been removed with preservation or even improvement ofvision.4,‘4,2’.2” When diffuse enlargement of the optic nerve can be demonstrated, as in the present case, surgical removal is virtually certain to result in loss of vision. Recently, because of the poor visual prognosis with surgery, orbital irradiation has been advocated as a primary mode of therapy, I9 This report documents several cases where visual acuity and field improved after irradiation. The longest followup on an eye where visual improvement was maintained was 16 months, and in this case the optociliary shunP also resolved. In one case where vision was “no light perception,” radiation was administered prophylactically to inhibit tumor growth. Before the effectiveness of any therapeutic intervention can be assessed, the natural history of the disease must be understood. Alper’s series suggests that optic nerve sheath meningiomas are relatively more aggressive tumors in young persons, with tumor-related deaths only in those under the age of 35.’ An attempt at complete surgical removal is therefore justified in younger persons. In older adults, the tumors are relatively slow-growing and
48
Surv Ophthalmol 28 (1) July-August
1983
nonaggressive, and Alper advocates following such patients clinically and with serial computerized tomograms until useful vision is lost or intracranial extension develops before deciding to intervene surgically. Since all optic nerve sheath meningiomas in my experience have shown progressive visual loss over a period of months to years, this approach effectively commits the patient to eventual surgery. The question remains: what is the morbidity and mortality of following older patients without therapy? Distant metastases are rare. Since we do not know what percentage of patients do eventually develop potentially life-threatening intracranial or painful local extension, we do not have the data to determine the appropriate management of primary optic nerve sheath meningioma in an older adult. Primary optic nerve sheath meningiomas are a clinically distinct entity now being recognized in large numbers, and a study to collect such information should not be too difficult to organize. Lacking these data, I am following several middle-aged women with “no light perception” vision in one eye and a normal fellow eye without any intervention, relying on serial clinical examinations and computerized tomography to alert me to significant tumor growth. I would pursue a similar course in the patient discussed here. Comments by Ronald M. Burde, M.D., Departments of Ophthalmology, Neurology and Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri From the lack of data, I presume Dr. Miller has presented a “straw horse” in order to review the arguments concerning the treatment of primary optic nerve sheath meningiomas. First, in terms of the diagnosis, progressive visual loss or visual loss that remains constant over a period of months accompanied by signs of optic nerve dysfunction (i.e., decreased Snellen acuity, dyschromatopsia, an afferent pupillary defect, and moderate disc swelling with a normal retina) obligates the physician to exclude the presence of a mass lesion. The additional finding of proptosis tends to place the lesion in the orbit, and this assumption was confirmed by a computerized tomographic (CT) study demonstrating enlargement of the posterior orbital optic nerve. The greater majority of times, such enlargement will be produced by an optic nerve glioma or by an optic nerve sheath meningioma. Optic nerve gliomas, with the exception of those rare malignant cases reported by Hoyt and associates’ (and the course in this case precludes such a diagnosis), are tumors of children and young adults. These tumors tend to cause enlargement of the optic canal, but without hyperostosis. Thus, the diagnosis of an op-
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ET AL
tic nerve sheath meningioma seems rather certain. It is ofinterest that although an association between optic nerve sheath meningiomas and neurolibromatosis has been suggested, I know of no hard evidence to support this contention. With respect to this patient in particular, I believe “watchful waiting” is in order. At what point intervention is necessary, e.g., with intracanalicular or intracranial extension, I am not sure is known. To be truly an iconoclast, one must ask what is the risk of blindness or death with intracranial extension versus the morbidity and mortality of transfrontal craniotomy. As to the dictum of Karp and colleagues,‘0 reiterated by Alper,’ that primary optic nerve sheath meningiomas in children are aggressive and dangerous tumors, I would reiterate the reservations expressed by Wright and associatesz4 that: (1) the cases were selected; (2) they occurred over a 40-year period and were therefore evaluated at a time when investigative modes were primitive; and (3) the pathologists were dependent upon the accuracy of history and clinical details supplied by others, and thus the meningiomatous tissue found in the orbit, primarily or secondarily may not have originated in the optic nerve. In addition, there does not appear to be any statistically valid evidence that such disfiguring surgery as exenteration has an effect on the survival rate of these patients. At the moment, the most justifiable admonition would be the statement by Goethe: “There is nothing more dangerous than ignorance in action.” Until further data are available, a priori ignorance suggests that the clinician would probably be safest to excise the tumor and optic nerve from the globe to the chiasm when all vision is lost. If the patient refuses such an approach, diagnostic biopsy followed by radiation therapy may supply us with the longitudinal data that Smith and colleagues need to back their suggestions.
References 1. Alper MG: Management of primary optic nerve meningiomas. Current status - therapy in controversy. J Clin Neuro-ophthalmol Z:lOl-117, 1981 2. Boschetti NV, Smith JL, Osher RH, et al: Fluorescein angiography ofoptociliary shunt vessels. J Clin Neuro-ophthalmol1.930, 1981 3. Burde RM, Gittinger JW, Keltner JL, Miller NR: Neuro-ophthalmologic dilemma: Chronic optic neuritis. Surv Ophthalmol .?3:173--176, 1978 4. Ebers GC, Giwin JP, Canny CB: A “possible” optic nerve meningioma. Arch New01 37: 781-783, 1980 5. Ellenberger C Jr: Perioptic meningiomas. Syndrome of longstanding visual loss, pale disk edema, and optociliary veins. Arch New01 33:671674, 1976 6. Frisen L, Hoyt WF, Tengroth BM: Optociliary veins, disc pallor and visual loss. Acta Ophthnlmol51:241-249, 1973
PROGRESSIVE VISUAL
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49
7. Gunby P: The new wave in medicine: nuclear magnetic resonance. JAM.4 247:151-159, 1982 8. Hoyt WF, Meshel LG, Lessell S, et al: Malignant optic glioma of adulthood. Brain 96:121-132, 1973 9. James AE, Price RR, Rollo F, et al: Nuclearmagnetic resonance imaging. A promising technique. JAMA 247:1331-1334, 1982 10. Karp LA, Zimmerman LE, Borit A, Spencer WH: Primary intraorbital meningiomas. Arch Ophthalmol 91:24-28, 1974 11, Kennerdell JS, Dekker A, Johnson BL, Dubois PJ: Fine-needle aspiration biopsy. Its use in orbital tumors. Arch Ophthalmol 97:1315-1317, 1979 12. Kennerdell JS, Dubois PJ, Dekker A, Johnson BL: CT-guided fme needle aspiration biopsy of orbital optic nerve tumors. Ophthalmolo~y 87:49 I-496, 1980 13. Krohel GB, Stewart WB, Chavis RM: Orbital Disease. A Practical Approach. New York, Grune and Stratton, 1981 14. Marc LE. Kennerdell JS, Maroon JC, et al: Microsurgical removal of a primary intraorbital meningioma. Am J Ophthalmol 86:704-709, 1978 15. Norris JL: Endoscopic orbital surgery. Report of a case. Arch 0phtha1mo199:140~1401, 1981 16. Norris JL, Cleasby GW: An endoscope for ophthalmology. Am J Ophthalmol R5:42&422. 1978
17. Norris JL, Cleasby GW: Endoscopic orbital surgery. Am J Ophthalmol 91:24%252, 1981 IS. Norris JL, Cleasby GW, Nakanishi AS, Martin I,J: Intraocular endoscopic surgery. Am J Ophthalmol9i:603-606, 1981 19. Smith JL, Vuksanovic MM, Yates BM, Bienfang DC: Radiation therapy for primary optic nerve meningiomas. J Clin Neuro-ophthalmol 1:8>99, I98 1 20. Spencer WH: Primary neoplasms of the optic nerve and its sheaths: Clinical features and current concepts of pathogenic mechanisms. Trans Am Ophthalmol Sot 70:49@528, 1972 21. Spencer WH, Hoyt WF: Chronic disc edema from neoplastic involvement of perioptic meninges, in Smith ME (ed): Ocular Pathology. Boston, Little Brown, 1972, pp 171-187 22. Torma T, Koskinen K: A case of unilateral optic foramen meningioma. Acta Ophthalmol39:460-465, 196 I 23. Wright JE: Primary optic nerve meningiomas. Clinical presentation and management. Tram Am Acad Ophthalmol Otolaryngol &‘:OP617425, 1977 24. Wright JE, Call NB, Liaricos S: Primary optic nerve meningioma. Br J Ophthalmol64:553-558, 1980
Reprints
are not available.
Abstract. A 43-year-old
woman presents with painless loss of vision in her left eye. She has decreased visual acuity, an afferent pupillary defect, slight proptosis and disc swelling, implying an optic nerve lesion. Computerized tomographic scanning shows generalized enlargement of the posterior orbital optic nerve. A presumed diagnosis ofan optic nerve sheath meningioma is made. The discussion deals with the problems of rational treatment. (Surv Ophthalmoi 28:4549, 1983)
Key words. progressive
meningioma visual loss l
l
tumor
optic nerve sheath
meningioma
l
orbital
apex mass
l
VOLUME 28.
NUMBER 1 . JULY-AUGUST
1983
CLINICAL CHALLENGES RONALD M. BURDE AND PAUL HENKIND, EDITORS
Progressive Visual Loss. What Type of Mass Lesion? NEIL R. MILLER,
M.D.
Comments by John L. Keltner, M.D., John W. Gittinger, Jr., M.D., and Ronald M. Burde, M.D. The Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, Maryland
(In keeping with thepurposes of a Clinical Pathological Conference, the abstract and kty words appear at the end of the article.)
A
performed that showed a generalized enlargement of the left posterior orbital optic nerve. No intracranial abnormalities were noted. Hypocycloidal polytomography suggested hyperostosis of the left optic canal.
43-year-old, previously healthy woman noted mild, painless, blurred vision in her left eye only. After this had persisted for several months she sak her ophthalmologist who noted left optic disc swelling and referred her for further evaluation. On examination, the visual acuity in the right eye was 20/l 5 at distance and J 1 at near. Visual acuity in the left eye was 20125 at distance and J2 at near. Color vision was normal in the right eye and slightly diminished in the left eye. The right visual field was full; the left visual field showed slight constriction. There was a left afferent pupillary defect. There was 2 mm of left exophthalmos. Ocular motility was normal. Ophthalmoscopy showed a normal right fundus. The left optic disc showed moderate swelling. What is your diagnosis? What is your management? Wouldyou changeyour management ifthe visual acuity were 20/400 or the visualJield were significantly constricted? A diagnosis of presumed compressive optic neuropathy was made, and computed tomography was
Comments Comments by John L. Keltner, M.D., Departments of Ophthalmology, Neurology, and Neurosurgery, Universi4 of California at Davis, Davis, Calfornia. Dr. Miller has described a case of a 43-year-old woman with minimal visual loss, constriction of her visual field, an afferent pupillary defect, and swelling of the left optic nerve. This constellation of signs and symptoms combined with the computerized axial tomography (CAT) scan showing abnormalities and hyperostosis of the left optic canal is fairly diagnostic of a primary optic nerve sheath meningioma. No mention is made about whether the patient has other signs of neurofibromatosis, but certainly “cafe au lait” spots and Lisch nodules on the 45
46
Surv Ophthalmol
28 (1) July-August
1983
iris, as well as a family history of neurofibromatosis, should be investigated. This patient did not demonstrate optociliary shunt vessels; however, progressive loss of vision, optic disc pallor and optociliary shunts constitute the clinical triad of optic nerve sheath meningiomas.6.20,2’ 0 P tociliary shunt vessels may also be seen following central retinal vein occlusions and, less commonly, they occur as a sequela of a variety of other conditions. Shunt vessels seen with optic nerve sheath meningiomas fill early in the arteriovenous phase of fluorescein angiography, and the flow drains to the central vein tributaries later in the angiogram and is hyperfluorescent to the other veins. In the central vein occlusion group, the shunt fills later in the venous phase.2l5 Before the introduction of CAT scanning, optic nerve sheath meningiomas often went undiagnosed or were misdiagnosed as “chronic optic neuritis.” Orbital venography, orbital x-ray and orbital exploration were the only diagnostic methods available until the advent of ultrasound and CAT scanning. Ultrasound generally has been difficult with posteriorly placed lesions such as the one described in this particular case. In general, ultrasound will provide a better tissue diagnosis in lesions that can be reached by this modality than will CAT scan in its present state of development. However, the recent development of nuclear magnetic resonance (NMR) scans will likely replace ultrasound and CAT scan as the best method for diagnosing and defining the histologic character of orbital lesions.‘,’ Two other techniques used in orbital diagnosis are orbital endoscopy and needle aspiration biopsy. Although neither of these techniques would probably be necessary in the present case, they should be mentioned. Over the last several years, Dr. John Norris at Pacific Medical Center in San Francisco has developed the technique of orbital endoscopy and has performed over 60 endoscopic procedures on the orbit.‘s’8 He has performed four biopsies through his endoscope and even has opened up one optic nerve sheath by orbital endoscopy on a child with an optic nerve glioma. In addition, Dr. Norris recently made a tissue diagnosis of mucormycosis by the endoscopic route. Another diagnostic technique used in the orbit is fine needle aspiration biopsy guided by CAT scan.“*‘2 While this technique has been successful in certain cases, it requires a good pathologist who is able to draw diagnostic conclusions from the cytologic preparations. In addition, it is more difficult to obtain adequate material if the lesion is both solid and cohesive. This procedure obviously is also not without risk, particularly in the hands of inexperienced surgeons, since there are many structures in
MILLER
ET AL
and around the orbit which might produce serious problems if inadvertently punctured. Finally, with the advent of computerized axial tomography and ultrasound, orbital exploration as a method for diagnosing tumors rarely has been needed in most cases. Now, with the introduction of nuclear magnetic resonance scanning and the possibility of orbital endoscopy becoming a more widely accepted technique, orbital exploration for biopsy probably will be performed very infrequently. The management of this patient, I believe, at the present time should be conservative.‘~‘3~24 Wright and associates2* and Alper’ recently have reviewed two large series of patients with primary optic nerve sheath meningiomas. Alper has differentiated these into patients under the age of 20, a group between ages 20 and 35, and those older than 35.’ The optic nerve sheath meningioma in a patient under age 20 appears to be especially aggressive and life-threatening. In the group between ages 20 and 35, the disease becomes less aggressive but still potentially life-threatening. In the group over age 35, the disease tends to be more indolent in its growth pattern. In the 20 to 35 age group, Alper recommends that once vision is lost an orbital operation should be performed with removal of the optic nerve and the If the tumor has escaped from the meningioma. dural sheath, he recommends a craniotomy and removal of the intracranial portion of the tumor. In the group over age 35, Alper recommends CAT scanning every six months with close clinical evaluation by visual fields and visual acuity, and if vision is lost in the eye, he recommends removal of the tumor. Wright and associates 24also report that the tumor should be removed once useful vision is gone. If the eye is blind, removal of all of the meningioma prevents growth of the tumor within the orbit or along the optic canal in the brain. If useful vision remains, incising the dura mater will relieve the pressure of the tumor; however, the results have been disappointing and all of the patients on whom Wright and his colleagues have performed this procedure have ended up with vision being destroyed within 18 months. In general, Wright and associates and Alper believe appropriate management is to wait for vision to deteriorate and then excise the optic nerve together with the meningioma. The exceptions to this would be: (1) if the growth rate of the tumor suggests a malignant-type of meningioma, the tumor should be biopsied; and (2) if a high resolution CAT scan shows a very small anterior tumor and useful vision remains, the nerve should be explored in an attempt to see whether the tumor can be removed without destroying vision. While several cases have been reported of SUC-
PROGRESSIVE
VISUAL
LOSS
cessful removal of primary optic nerve sheath meningiomas, 4,14.1gtheir successful removal and preservation of vision have been rare. The reason for this would appear to be that the vascular supply of the optic nerve is compromised by any dissection necessary to remove the meningioma from the optic nerve. Radiation therapy for optic nerve sheath meningiomas has been suggested by Smith and colleagues. I9 They cite one patient whose vision had deteriorated to hand motions and after 5220 rads of radiation therapy recovered to 20/70 for 18 months; however, the fields subsequently deteriorated, and there was no followup reported after 42 months. Others have reported radiation therapy for intracranial meningiomas with variable results. In general, radiation therapy has been reserved for histologically malignant or clinically invasive meningiomas. In this particular patient, because of her age, I believe a conservative approach should be undertaken, waiting until vision falls to less than 20/400. At that time, if the patient understands the risks and benefits of the surgical procedure involved, I believe a surgical removal may be in order. Until we have more information on the effects of radiation on this type of tumor, both long- and short-term, I would be reluctant to treat this patient with radiation therapy. If the patient refused to follow this recommendation, I believe that an equally cogent argument could be made for following this patient without intervention. Serial CAT scans certainly could be used to identify any intracranial spread of this tumor. Even though there will be some tumors that will invade intracranially and be missed by CAT scan, high resolution scanners will be able to detect most significant intracranial involvement. If the tumor expands rapidly in the orbit with loss of vision, this might push the surgeon to consider surgical removal once the eye is blind rather than continuing with conservative management. There is no question that we need more information not only about the natural history ofoptic nerve sheath meningiomas but also about the appropriate treatment modalities. Hopefully, a multicenter combined series could answer these types of questions, and I believe there is a strong need for this type of study.
Comments by John W. Gittinger, Jr., M.D., Division of Ophthalmology, University of Massachusetts, Worcester, Massachusetts In this middle-aged woman with disc swelling, an afferent pupillary defect, and unilateral visual dysfunction, enlargement of the optic nerve on computerized tomography is virtually diagnostic of primary
47
optic nerve sheath meningioma. The combination of disc swelling and optic nerve enlargement is also seen with optic nerve gliomas, but this is a tumor of children and young adults, and the enlargement is characteristically fusiform. Also, optic nerve gliomas expand the optic foramen but do not induce hyperostosis. The development of computerized tomography has greatly facilitated the detection of primary optic nerve sheath meningiomas, but in spite of the resolution of the newer generation scanners it is not always an easy diagnosis to make.” In this patient, when a tumor was found at the time of surgical exploration, excisional biopsy was the obvious approach. However, now that the diagnosis can be made with confidence by a simple, noninvasive study, the question of management is more difficult. Surgical removal of primary optic nerve sheath meningiomas is complicated by the arrangement of the vascular supply of the optic nerve. In the optic canal the ophthalmic artery lies within the subarachnoid space; it then becomes extradural and sends branches through the meninges to supply the retrolaminar nerve. Meningiomas arise from the arachnoid, and the intimate relationship between the meninges and optic nerve vascular supply assures that the tumor’s vascular supply and that of the adjacent optic nerve are interdependent. Removal of the tumor thus results in blindness of the ipsilateral eye. Rarely, when the tumor is discrete (or perhaps does not arise directly from the meninges themselves), meningiomas have been removed with preservation or even improvement ofvision.4,‘4,2’.2” When diffuse enlargement of the optic nerve can be demonstrated, as in the present case, surgical removal is virtually certain to result in loss of vision. Recently, because of the poor visual prognosis with surgery, orbital irradiation has been advocated as a primary mode of therapy, I9 This report documents several cases where visual acuity and field improved after irradiation. The longest followup on an eye where visual improvement was maintained was 16 months, and in this case the optociliary shunP also resolved. In one case where vision was “no light perception,” radiation was administered prophylactically to inhibit tumor growth. Before the effectiveness of any therapeutic intervention can be assessed, the natural history of the disease must be understood. Alper’s series suggests that optic nerve sheath meningiomas are relatively more aggressive tumors in young persons, with tumor-related deaths only in those under the age of 35.’ An attempt at complete surgical removal is therefore justified in younger persons. In older adults, the tumors are relatively slow-growing and
48
Surv Ophthalmol 28 (1) July-August
1983
nonaggressive, and Alper advocates following such patients clinically and with serial computerized tomograms until useful vision is lost or intracranial extension develops before deciding to intervene surgically. Since all optic nerve sheath meningiomas in my experience have shown progressive visual loss over a period of months to years, this approach effectively commits the patient to eventual surgery. The question remains: what is the morbidity and mortality of following older patients without therapy? Distant metastases are rare. Since we do not know what percentage of patients do eventually develop potentially life-threatening intracranial or painful local extension, we do not have the data to determine the appropriate management of primary optic nerve sheath meningioma in an older adult. Primary optic nerve sheath meningiomas are a clinically distinct entity now being recognized in large numbers, and a study to collect such information should not be too difficult to organize. Lacking these data, I am following several middle-aged women with “no light perception” vision in one eye and a normal fellow eye without any intervention, relying on serial clinical examinations and computerized tomography to alert me to significant tumor growth. I would pursue a similar course in the patient discussed here. Comments by Ronald M. Burde, M.D., Departments of Ophthalmology, Neurology and Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri From the lack of data, I presume Dr. Miller has presented a “straw horse” in order to review the arguments concerning the treatment of primary optic nerve sheath meningiomas. First, in terms of the diagnosis, progressive visual loss or visual loss that remains constant over a period of months accompanied by signs of optic nerve dysfunction (i.e., decreased Snellen acuity, dyschromatopsia, an afferent pupillary defect, and moderate disc swelling with a normal retina) obligates the physician to exclude the presence of a mass lesion. The additional finding of proptosis tends to place the lesion in the orbit, and this assumption was confirmed by a computerized tomographic (CT) study demonstrating enlargement of the posterior orbital optic nerve. The greater majority of times, such enlargement will be produced by an optic nerve glioma or by an optic nerve sheath meningioma. Optic nerve gliomas, with the exception of those rare malignant cases reported by Hoyt and associates’ (and the course in this case precludes such a diagnosis), are tumors of children and young adults. These tumors tend to cause enlargement of the optic canal, but without hyperostosis. Thus, the diagnosis of an op-
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ET AL
tic nerve sheath meningioma seems rather certain. It is ofinterest that although an association between optic nerve sheath meningiomas and neurolibromatosis has been suggested, I know of no hard evidence to support this contention. With respect to this patient in particular, I believe “watchful waiting” is in order. At what point intervention is necessary, e.g., with intracanalicular or intracranial extension, I am not sure is known. To be truly an iconoclast, one must ask what is the risk of blindness or death with intracranial extension versus the morbidity and mortality of transfrontal craniotomy. As to the dictum of Karp and colleagues,‘0 reiterated by Alper,’ that primary optic nerve sheath meningiomas in children are aggressive and dangerous tumors, I would reiterate the reservations expressed by Wright and associatesz4 that: (1) the cases were selected; (2) they occurred over a 40-year period and were therefore evaluated at a time when investigative modes were primitive; and (3) the pathologists were dependent upon the accuracy of history and clinical details supplied by others, and thus the meningiomatous tissue found in the orbit, primarily or secondarily may not have originated in the optic nerve. In addition, there does not appear to be any statistically valid evidence that such disfiguring surgery as exenteration has an effect on the survival rate of these patients. At the moment, the most justifiable admonition would be the statement by Goethe: “There is nothing more dangerous than ignorance in action.” Until further data are available, a priori ignorance suggests that the clinician would probably be safest to excise the tumor and optic nerve from the globe to the chiasm when all vision is lost. If the patient refuses such an approach, diagnostic biopsy followed by radiation therapy may supply us with the longitudinal data that Smith and colleagues need to back their suggestions.
References 1. Alper MG: Management of primary optic nerve meningiomas. Current status - therapy in controversy. J Clin Neuro-ophthalmol Z:lOl-117, 1981 2. Boschetti NV, Smith JL, Osher RH, et al: Fluorescein angiography ofoptociliary shunt vessels. J Clin Neuro-ophthalmol1.930, 1981 3. Burde RM, Gittinger JW, Keltner JL, Miller NR: Neuro-ophthalmologic dilemma: Chronic optic neuritis. Surv Ophthalmol .?3:173--176, 1978 4. Ebers GC, Giwin JP, Canny CB: A “possible” optic nerve meningioma. Arch New01 37: 781-783, 1980 5. Ellenberger C Jr: Perioptic meningiomas. Syndrome of longstanding visual loss, pale disk edema, and optociliary veins. Arch New01 33:671674, 1976 6. Frisen L, Hoyt WF, Tengroth BM: Optociliary veins, disc pallor and visual loss. Acta Ophthnlmol51:241-249, 1973
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7. Gunby P: The new wave in medicine: nuclear magnetic resonance. JAM.4 247:151-159, 1982 8. Hoyt WF, Meshel LG, Lessell S, et al: Malignant optic glioma of adulthood. Brain 96:121-132, 1973 9. James AE, Price RR, Rollo F, et al: Nuclearmagnetic resonance imaging. A promising technique. JAMA 247:1331-1334, 1982 10. Karp LA, Zimmerman LE, Borit A, Spencer WH: Primary intraorbital meningiomas. Arch Ophthalmol 91:24-28, 1974 11, Kennerdell JS, Dekker A, Johnson BL, Dubois PJ: Fine-needle aspiration biopsy. Its use in orbital tumors. Arch Ophthalmol 97:1315-1317, 1979 12. Kennerdell JS, Dubois PJ, Dekker A, Johnson BL: CT-guided fme needle aspiration biopsy of orbital optic nerve tumors. Ophthalmolo~y 87:49 I-496, 1980 13. Krohel GB, Stewart WB, Chavis RM: Orbital Disease. A Practical Approach. New York, Grune and Stratton, 1981 14. Marc LE. Kennerdell JS, Maroon JC, et al: Microsurgical removal of a primary intraorbital meningioma. Am J Ophthalmol 86:704-709, 1978 15. Norris JL: Endoscopic orbital surgery. Report of a case. Arch 0phtha1mo199:140~1401, 1981 16. Norris JL, Cleasby GW: An endoscope for ophthalmology. Am J Ophthalmol R5:42&422. 1978
17. Norris JL, Cleasby GW: Endoscopic orbital surgery. Am J Ophthalmol 91:24%252, 1981 IS. Norris JL, Cleasby GW, Nakanishi AS, Martin I,J: Intraocular endoscopic surgery. Am J Ophthalmol9i:603-606, 1981 19. Smith JL, Vuksanovic MM, Yates BM, Bienfang DC: Radiation therapy for primary optic nerve meningiomas. J Clin Neuro-ophthalmol 1:8>99, I98 1 20. Spencer WH: Primary neoplasms of the optic nerve and its sheaths: Clinical features and current concepts of pathogenic mechanisms. Trans Am Ophthalmol Sot 70:49@528, 1972 21. Spencer WH, Hoyt WF: Chronic disc edema from neoplastic involvement of perioptic meninges, in Smith ME (ed): Ocular Pathology. Boston, Little Brown, 1972, pp 171-187 22. Torma T, Koskinen K: A case of unilateral optic foramen meningioma. Acta Ophthalmol39:460-465, 196 I 23. Wright JE: Primary optic nerve meningiomas. Clinical presentation and management. Tram Am Acad Ophthalmol Otolaryngol &‘:OP617425, 1977 24. Wright JE, Call NB, Liaricos S: Primary optic nerve meningioma. Br J Ophthalmol64:553-558, 1980
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are not available.
Abstract. A 43-year-old
woman presents with painless loss of vision in her left eye. She has decreased visual acuity, an afferent pupillary defect, slight proptosis and disc swelling, implying an optic nerve lesion. Computerized tomographic scanning shows generalized enlargement of the posterior orbital optic nerve. A presumed diagnosis ofan optic nerve sheath meningioma is made. The discussion deals with the problems of rational treatment. (Surv Ophthalmoi 28:4549, 1983)
Key words. progressive
meningioma visual loss l
l
tumor
optic nerve sheath
meningioma
l
orbital
apex mass
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