Large Optic Nerve Glioma With Normal Vision Stanley
J.
Goodman, MD;
Arthur L.
Rosenbaum, MD; Anton Hasso, MD; Hideo Itabashi,
\s=b\ When the diagnosis of optic glioma is made, the visual loss is most often mildly or profoundly impaired. We report the de-
tails of the unusual situation where central visual acuity, visual fields, and color vision were normal at the time a large optic nerve glioma was demonstrated in a young boy. To our knowledge, this is the first case report containing ophthalmologic, neuroradiologic, surgical, and histologic details illustrating the rare association of normal vision and an optic
glioma. (Arch Ophthalmol 93:991-995, 1975)
and progres¬ are the sive loss of visual most common clinical features in pa¬ tients with optic nerve gliomas. Vi¬ sual loss is severe at the time of diag¬ nosis in approximately half of the patients,1 and some degree of dimin¬ ished visual acuity can be demon¬ strated in almost every case, except those patients who are too young to test.24 One case report has drawn at¬ tention to the rare patient who may have normal vision or very minimal
Unilateral proptosis acuity
Submitted for publication Aug 15, 1974. From the departments of surgery (neurosurgery), ophthalmology, radiology, and pathology, Harbor General Hospital, Torrance, Calif, and the UCLA School of Medicine, Los Angeles. Reprint requests to Harbor General Hospital, 100 W Carson St, Torrance, CA 90509 (Dr. Good-
man).
visual dysfunction.5 We report the unusual observation of normal visual function despite the presence of a very large optic nerve glioma extending from the optic disc to the chiasm.
REPORT OF A CASE A 6%-year-old boy was referred to Har¬ bor General Hospital in January 1974, af¬ ter physicians had detected papilledema in the right eye. The patient had been in excellent health until one month prior to admission, when he complained of diffuse intermittent headache. The headache had no relation to activity, position, disposition, or time of day, and tended to last for an entire day about twice weekly. Frequently, the pain was intense, and the patient occasional¬ ly vomited during severe headaches. Loud noises were bothersome at times, and he became uncharacteristically irritable and less interested in play. The mother de¬ scribed an isolated incident during this time which lasted one hour, when the pa¬ tient "lost control of his eyes and was unable to straighten them out." The mother also noted occasional intermittent drooping of the right eyelid. The past history, review of systems, de¬ velopmental history, and family history were unremarkable. A family history of neurofibromatosis was not obtained. Monocular papilledema was seen by a pediatrician two weeks prior to admission and was confirmed by an ophthalmologist. Routine skull x-ray films, brain scan, and a
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
MD
lumbar-puncture cerebrospinal fluid exam¬ ination all disclosed no abnormality. The child
was
then referred to Harbor General
Hospital. Papilledema and minimal proptosis of the right eye were the only abnormalities detected on physical examination. Ocular examination showed best corrected visual acuity of 20/20-2 OD and 20/25+1 OS. Monocular color vision testing detected no errors with the pseudoisochromatic plates. External and slit lamp examination were unremarkable. Extraocular muscle rota¬ tions were full and without limitation. Pu¬ pils were 6 mm in size in both eyes and re¬ acted briskly to light and accommodation. Exophthalmometer readings were 15 on the right side and 13 on the left. Intraocu¬ lar pressure was not elevated. Visual field testing disclosed an enlarged blind spot in the right eye. Papilledema of the right optic disc with venous engorgement and small papillary hemorrhages was noted. The patient's height, weight, and head cir¬ cumference were all normal. Results of blood pressure, pulse, respiration, and gen¬ eral physical examination were normal. There were no café-au-lait spots. The child was of normal intelligence and affect. Radiologie examination showed that the right optic foramen was enlarged to 9 mm (Fig 1 and 2). Selective internal carotid angiography demonstrated that the in¬ traorbital portion of the ophthalmic artery was displaced downward and somewhat splayed laterally. Hypocycloidal tomographic cuts during the pneumoencephalogram displayed a tumor that was 7 to 10 mm in diameter extending from within the
Fig 1 .—Magnified right optic foramen view. Right optic foramen expanded In symmetrical manner. Note thinning of bony cortex surrounding optic foramen, but no destruction. R indicates right.
tex. L indicates left.
Fig 3.—Hypocycloidal tomogram at level of optic foramen dur¬ ing brow-up pneumoencephalography. Note enlargement of right optic foramen, with thinning of inferior medial margin of right an¬ terior clinoid (lower arrow). In addition, there is thinning of the su¬ perior margin of the right optic foramen with loss of the cortical margin (upper arrow). R indicates right.
Fig 4.—Hypocycloidal tomogram 2 mm posterior to Fig 3 during brow-up pneumoencephalography. Planum sphenoidal Is tilted downward to right. Right anterior clinoid shows medial erosion (lower arrow). The elliptically enlarged right optic nerve is seen to bulge superiorly into chiasmatic cistern (upper arrow). Left optic nerve Is of normal size, without evidence of bony erosion.
is
Fig 2—Magnified left optic foramen view. In comparison to Fig 1, left optic foramen is of normal size and shows Intact bony cor¬
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Fig 6.—Top, Gross surgical specimen with red bulbous proximal end at left and distal portion cut flush to globe at right. Note maintenance of anatomic opened Sshape and fusiform expansion. Bottom, Same specimen showing gross appear¬ ance of cut surfaces at various levels.
yellow-tan. The end toward the
Fig 5.—Linear midsagittal tomogram during brow-up pneumoencephalography. Optic chiasm Is of normal size, as it extends upwards into optic recess (narrow and wide ar¬ rows point to edges of optic chiasm). Anterior recesses of third ventricle are not blunted (recesses outlined with dots). Diagnosis of right optic nerve tumor without chiasmatic in¬ volvement can be made.
orbit, through the length of the optic canal,
continuing intracranially ing edge of the chiasm (Fig 3 through 5). Because of the unusual finding of an ap¬ parent optic nerve tumor and normal vi¬ sion, the child was reexamined in detail with no change in the results of ophthalmic and
to the lead¬
examination.
Through a right frontal craniotomy, a bulbously enlarged and mildly hyperemic intracranial right optic nerve was seen. The enlarged portion of the nerve and the hyperemia stopped about 1.5 mm in front of the optic chiasm. The optic canal was unroofed, and moderate inflammatory-like adhesions between the nerve and the durai sheath were divided. The orbit was un¬ roofed, the nerve followed to the globe, and the nerve was amputated less than 1 mm in front of the chiasm and 1.5 mm behind the globe. The surgical specimen appeared to have a 1-mm cuff of normal nerve at each end. The patient had an uncomplicated post¬ operative course, except for ptosis and
medial rectus palsy of the right eye. The ptosis is gradually improving. Visual acu¬ ity and visual field is entirely normal in the left eye. Radiation therapy has not been used.
PATHOLOGIC FINDINGS
The
excised, enlarged, right optic
consisted of an S-shaped, elon¬ firm tissue measuring 3.7 cm in gated length and 0.5 to 0.9 cm in diameter that was invested with transparent arachnoid containing fine blood ves¬ sels. The end of the nerve, which was described as being toward the chiasm, was red and bulbous, whereas the end toward the globe that was marked by a surgical clip had a nearly normal appearance (Fig 6, top). The inter¬ nerve
vening segment was diffusely en¬ larged. On section examination, the enlarged portion of the nerve was slightly translucent and red-tan to
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
eye
had a more normal white appearance of optic nerve (Fig 6, bottom). The specimen was fixed in 30% neutral formaldehyde solution, embedded in paraffin, sectioned, and stained with
hematoxylin-eosin. Klüver-Barrera, Masson trichrome, PAS, Bodian, and Hölzer methods. Other stains applied
colloidal iron method for acid mucopolysaccarides, PAS-Alcian blue method for mucosubstances, and mucicarmine stain for mucin. Microscopically, the general archi¬ tecture of the nerve was maintained, but the usual diameter was increased by enlargement of the nerve bun¬ dles and concomitant stretching and thickening of the connective tissue (Fig 7). The tumor remained confined within the slightly thickened but in¬ tact investing pia-arachnoid. There was noticeable congestion and hypervascularity within the septae, corre¬ sponding to the grossly noted red, bulbous segment. Except for some myelin that was demonstrable at the extreme periphery of the nerve, there were
demyelination through¬ hand, Bodian stain showed relatively good preservation of axis cylinders (Fig 8). The tumor was
severe
out. On the other
Fig 7—Left, Cross section of optic nerve expanded by tumor. Note enlarged nerve fascicles and slightly thickened and stretched connective tissue septae (Hematoxylin-eosin, original magnification 12.5). Right, High-power view of tumor cells. Tu-
astrocytes are indicated by arrows. Note large vesicular prominent processes (hematoxylin-eosin, original magnification 275). mor
nuclei and
Fig 8.—High-power view showing relative preservation of axis cylinders between astrocytes (arrows) in (right) sections. (Bodian, original magnification 375).
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
cross
(left)
and
longitudinal
cells
were sparsely distributed, welldifferentiated, fibrillary astrocytes, although occasional large forms with
vesicular and lobulated nuclei
were
present (Fig 8). Although astrocytic nuclei were relatively sparse, abun¬ dant fibrillary processes replaced the degenerated tissue. Necrosis, inflam¬ mation, and evidence of phagocytic activity were absent. No appreciable spongy change or large extracellular spaces were present, and histochemi¬ cal stains for mucosubstances, mucin, and acid mucopolysaccharides were negative. There appeared to be nor¬ mal nerve at both ends of the speci¬ men. No multinucleated cells or mi¬ toses were noted. Rosenthal fibers were absent. The histological diag¬ nosis was optic nerve glioma, and the nerve enlargement would appear to have been the result of proliferation of astrocytes and their processes. COMMENT
This case illustrates that central vi¬ sual acuity and color perception may be entirely normal in the presence of a large optic nerve glioma. The litera¬ ture contains brief comments regard¬ ing preserved central acuity of 20/20 in the involved eyes of five patients with surgically confirmed optic nerve glioma. In one report, visual fields and color vision were not mentioned, but the authors indicated they were surprised to have found two instances of optic nerve glioma sufficiently large to cause monocular proptosis yet still associated with normal cen¬ tral acuity.6 The actual size of the two tumors was not mentioned. In an¬ other report, 53 of 56 patients with optic glioma who were followed over a period of many years had subjective or objective evidence, or both, of vi¬ sual failure at the time the diagnosis was made.3 However, no details con¬ cerning the three of 56 patients with
presumably normal
visual acuity can be extracted from the report. The im¬ portant point that has been recog¬ nized, but not emphasized, is that gliomas infiltrating the optic nerve may rarely have no clinically detect¬ able decrease in visual acuity or color vision. In retrospect, more detailed tests such as pupilography, visually evoked cortical response, more exten¬ sive color vision testing, and determi¬ nation of modular transfer function might have disclosed some afferent defect of the right optic nerve. There may be a relatively pro¬ longed course of tumor growth of op¬ tic nerve gliomas, during which time vision is not affected. As these slowly infiltrative tumors expand, they grad¬ ually separate and distort the longi¬
tudinally arranged axons, yet many functioning axons undoubtedly sur¬ vive for a long time so that they are seen microscopically to have an unin¬ terrupted anatomical course through
the midst of the tumor. Vision ulti¬ mately fails with chiasmatic and op¬ tic nerve gliomas as the tumor bulk continues to disturb anatomical-me¬ chanical and vascular needs of the anterior visual pathway. However, in the case of many optic nerve gliomas, another reason for ultimately failing vision may be that of compressive force on the nerve within the optic ca¬ nal. As the tumor slowly grows within the restricted confines of the optic ca¬ nal, it exerts force both centrifugally and centripetally: bony erosion occurs externally and demyelination occurs in the nerve. Eventually, there is disruption of axis cylinders. Enlarge¬ ment of the optic nerve has been at¬ tributed to accumulation of muco¬ substances,7 but morphologic and histochemical evidence of the pres¬ ence of such substances was absent from the present case. Rather, the en¬ largement resulted from infiltration
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
and replacement of the nerve by as¬ trocytes and their processes, along
with some thickening of the connec¬ tive tissue septae. Surgical removal was selected in this case because of the radiologie and anatomic evidence of tumor exten¬ sion to within 1.5 mm of the optic chiasm. We are aware of the mean¬ ingful controversy surrounding the treatment of optic nerve gliomas, but we believe that a discussion of this complicated subject is beyond the scope of this presentation. This patient became symptomatic with the abrupt onset of diffuse head¬ aches. At surgery, we found an en¬ larged optic nerve with inflammatory adhesions between the hyperemic tu¬ mor within the optic canal and the surrounding durai sheath. It is pos¬ sible that this child's optic nerve glioma was diagnosed before vision began to fail because early durai in¬ volvement led to pain and headaches.
Robert Helper, MD, assisted in the prepara}n of this report tion report.
References 1. Walsh FG, Hoyt WF: Clinical Neuro-Ophthalmology, ed 3. Baltimore, Williams & Wilkins Co, 1969, vol 3, pp 2076-2094. 2. Verhoeff FH: Primary intraneural tumors (gliomas) of the optic nerve. Arch Ophthalmol 51:120-140, 1922. 3. Chutorian AM, Schwartz JF, Evans RA, et al: Optic gliomas in children. Neurology 14:83-95,
1964.
4. Udvarhelyi GB, Khodadoust AA, Walsh FB: Gliomas of the optic nerve and chiasm in children: An unusual series of cases. Clin Neurosurg
13:204-237,
1966. 5. Jummelt K: Spongioblastoma des nervus opticus mit guter funktion des auges. Klin Monatsbl Augenheilkd 125:591-594, 1954. 6. Dodge HW Jr, Love JG, Craig WM, et al: Gliomas of the optic nerves. Arch Neurol Psychiatr 79:607-621, 1958. 7. Anderson DR, Spencer WH: Ultrastructural and histochemical observations of optic nerve gliomas. Arch Ophthalmol 83:324-335, 1970.
J.
Goodman, MD;
Arthur L.
Rosenbaum, MD; Anton Hasso, MD; Hideo Itabashi,
\s=b\ When the diagnosis of optic glioma is made, the visual loss is most often mildly or profoundly impaired. We report the de-
tails of the unusual situation where central visual acuity, visual fields, and color vision were normal at the time a large optic nerve glioma was demonstrated in a young boy. To our knowledge, this is the first case report containing ophthalmologic, neuroradiologic, surgical, and histologic details illustrating the rare association of normal vision and an optic
glioma. (Arch Ophthalmol 93:991-995, 1975)
and progres¬ are the sive loss of visual most common clinical features in pa¬ tients with optic nerve gliomas. Vi¬ sual loss is severe at the time of diag¬ nosis in approximately half of the patients,1 and some degree of dimin¬ ished visual acuity can be demon¬ strated in almost every case, except those patients who are too young to test.24 One case report has drawn at¬ tention to the rare patient who may have normal vision or very minimal
Unilateral proptosis acuity
Submitted for publication Aug 15, 1974. From the departments of surgery (neurosurgery), ophthalmology, radiology, and pathology, Harbor General Hospital, Torrance, Calif, and the UCLA School of Medicine, Los Angeles. Reprint requests to Harbor General Hospital, 100 W Carson St, Torrance, CA 90509 (Dr. Good-
man).
visual dysfunction.5 We report the unusual observation of normal visual function despite the presence of a very large optic nerve glioma extending from the optic disc to the chiasm.
REPORT OF A CASE A 6%-year-old boy was referred to Har¬ bor General Hospital in January 1974, af¬ ter physicians had detected papilledema in the right eye. The patient had been in excellent health until one month prior to admission, when he complained of diffuse intermittent headache. The headache had no relation to activity, position, disposition, or time of day, and tended to last for an entire day about twice weekly. Frequently, the pain was intense, and the patient occasional¬ ly vomited during severe headaches. Loud noises were bothersome at times, and he became uncharacteristically irritable and less interested in play. The mother de¬ scribed an isolated incident during this time which lasted one hour, when the pa¬ tient "lost control of his eyes and was unable to straighten them out." The mother also noted occasional intermittent drooping of the right eyelid. The past history, review of systems, de¬ velopmental history, and family history were unremarkable. A family history of neurofibromatosis was not obtained. Monocular papilledema was seen by a pediatrician two weeks prior to admission and was confirmed by an ophthalmologist. Routine skull x-ray films, brain scan, and a
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
MD
lumbar-puncture cerebrospinal fluid exam¬ ination all disclosed no abnormality. The child
was
then referred to Harbor General
Hospital. Papilledema and minimal proptosis of the right eye were the only abnormalities detected on physical examination. Ocular examination showed best corrected visual acuity of 20/20-2 OD and 20/25+1 OS. Monocular color vision testing detected no errors with the pseudoisochromatic plates. External and slit lamp examination were unremarkable. Extraocular muscle rota¬ tions were full and without limitation. Pu¬ pils were 6 mm in size in both eyes and re¬ acted briskly to light and accommodation. Exophthalmometer readings were 15 on the right side and 13 on the left. Intraocu¬ lar pressure was not elevated. Visual field testing disclosed an enlarged blind spot in the right eye. Papilledema of the right optic disc with venous engorgement and small papillary hemorrhages was noted. The patient's height, weight, and head cir¬ cumference were all normal. Results of blood pressure, pulse, respiration, and gen¬ eral physical examination were normal. There were no café-au-lait spots. The child was of normal intelligence and affect. Radiologie examination showed that the right optic foramen was enlarged to 9 mm (Fig 1 and 2). Selective internal carotid angiography demonstrated that the in¬ traorbital portion of the ophthalmic artery was displaced downward and somewhat splayed laterally. Hypocycloidal tomographic cuts during the pneumoencephalogram displayed a tumor that was 7 to 10 mm in diameter extending from within the
Fig 1 .—Magnified right optic foramen view. Right optic foramen expanded In symmetrical manner. Note thinning of bony cortex surrounding optic foramen, but no destruction. R indicates right.
tex. L indicates left.
Fig 3.—Hypocycloidal tomogram at level of optic foramen dur¬ ing brow-up pneumoencephalography. Note enlargement of right optic foramen, with thinning of inferior medial margin of right an¬ terior clinoid (lower arrow). In addition, there is thinning of the su¬ perior margin of the right optic foramen with loss of the cortical margin (upper arrow). R indicates right.
Fig 4.—Hypocycloidal tomogram 2 mm posterior to Fig 3 during brow-up pneumoencephalography. Planum sphenoidal Is tilted downward to right. Right anterior clinoid shows medial erosion (lower arrow). The elliptically enlarged right optic nerve is seen to bulge superiorly into chiasmatic cistern (upper arrow). Left optic nerve Is of normal size, without evidence of bony erosion.
is
Fig 2—Magnified left optic foramen view. In comparison to Fig 1, left optic foramen is of normal size and shows Intact bony cor¬
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
Fig 6.—Top, Gross surgical specimen with red bulbous proximal end at left and distal portion cut flush to globe at right. Note maintenance of anatomic opened Sshape and fusiform expansion. Bottom, Same specimen showing gross appear¬ ance of cut surfaces at various levels.
yellow-tan. The end toward the
Fig 5.—Linear midsagittal tomogram during brow-up pneumoencephalography. Optic chiasm Is of normal size, as it extends upwards into optic recess (narrow and wide ar¬ rows point to edges of optic chiasm). Anterior recesses of third ventricle are not blunted (recesses outlined with dots). Diagnosis of right optic nerve tumor without chiasmatic in¬ volvement can be made.
orbit, through the length of the optic canal,
continuing intracranially ing edge of the chiasm (Fig 3 through 5). Because of the unusual finding of an ap¬ parent optic nerve tumor and normal vi¬ sion, the child was reexamined in detail with no change in the results of ophthalmic and
to the lead¬
examination.
Through a right frontal craniotomy, a bulbously enlarged and mildly hyperemic intracranial right optic nerve was seen. The enlarged portion of the nerve and the hyperemia stopped about 1.5 mm in front of the optic chiasm. The optic canal was unroofed, and moderate inflammatory-like adhesions between the nerve and the durai sheath were divided. The orbit was un¬ roofed, the nerve followed to the globe, and the nerve was amputated less than 1 mm in front of the chiasm and 1.5 mm behind the globe. The surgical specimen appeared to have a 1-mm cuff of normal nerve at each end. The patient had an uncomplicated post¬ operative course, except for ptosis and
medial rectus palsy of the right eye. The ptosis is gradually improving. Visual acu¬ ity and visual field is entirely normal in the left eye. Radiation therapy has not been used.
PATHOLOGIC FINDINGS
The
excised, enlarged, right optic
consisted of an S-shaped, elon¬ firm tissue measuring 3.7 cm in gated length and 0.5 to 0.9 cm in diameter that was invested with transparent arachnoid containing fine blood ves¬ sels. The end of the nerve, which was described as being toward the chiasm, was red and bulbous, whereas the end toward the globe that was marked by a surgical clip had a nearly normal appearance (Fig 6, top). The inter¬ nerve
vening segment was diffusely en¬ larged. On section examination, the enlarged portion of the nerve was slightly translucent and red-tan to
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
eye
had a more normal white appearance of optic nerve (Fig 6, bottom). The specimen was fixed in 30% neutral formaldehyde solution, embedded in paraffin, sectioned, and stained with
hematoxylin-eosin. Klüver-Barrera, Masson trichrome, PAS, Bodian, and Hölzer methods. Other stains applied
colloidal iron method for acid mucopolysaccarides, PAS-Alcian blue method for mucosubstances, and mucicarmine stain for mucin. Microscopically, the general archi¬ tecture of the nerve was maintained, but the usual diameter was increased by enlargement of the nerve bun¬ dles and concomitant stretching and thickening of the connective tissue (Fig 7). The tumor remained confined within the slightly thickened but in¬ tact investing pia-arachnoid. There was noticeable congestion and hypervascularity within the septae, corre¬ sponding to the grossly noted red, bulbous segment. Except for some myelin that was demonstrable at the extreme periphery of the nerve, there were
demyelination through¬ hand, Bodian stain showed relatively good preservation of axis cylinders (Fig 8). The tumor was
severe
out. On the other
Fig 7—Left, Cross section of optic nerve expanded by tumor. Note enlarged nerve fascicles and slightly thickened and stretched connective tissue septae (Hematoxylin-eosin, original magnification 12.5). Right, High-power view of tumor cells. Tu-
astrocytes are indicated by arrows. Note large vesicular prominent processes (hematoxylin-eosin, original magnification 275). mor
nuclei and
Fig 8.—High-power view showing relative preservation of axis cylinders between astrocytes (arrows) in (right) sections. (Bodian, original magnification 375).
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
cross
(left)
and
longitudinal
cells
were sparsely distributed, welldifferentiated, fibrillary astrocytes, although occasional large forms with
vesicular and lobulated nuclei
were
present (Fig 8). Although astrocytic nuclei were relatively sparse, abun¬ dant fibrillary processes replaced the degenerated tissue. Necrosis, inflam¬ mation, and evidence of phagocytic activity were absent. No appreciable spongy change or large extracellular spaces were present, and histochemi¬ cal stains for mucosubstances, mucin, and acid mucopolysaccharides were negative. There appeared to be nor¬ mal nerve at both ends of the speci¬ men. No multinucleated cells or mi¬ toses were noted. Rosenthal fibers were absent. The histological diag¬ nosis was optic nerve glioma, and the nerve enlargement would appear to have been the result of proliferation of astrocytes and their processes. COMMENT
This case illustrates that central vi¬ sual acuity and color perception may be entirely normal in the presence of a large optic nerve glioma. The litera¬ ture contains brief comments regard¬ ing preserved central acuity of 20/20 in the involved eyes of five patients with surgically confirmed optic nerve glioma. In one report, visual fields and color vision were not mentioned, but the authors indicated they were surprised to have found two instances of optic nerve glioma sufficiently large to cause monocular proptosis yet still associated with normal cen¬ tral acuity.6 The actual size of the two tumors was not mentioned. In an¬ other report, 53 of 56 patients with optic glioma who were followed over a period of many years had subjective or objective evidence, or both, of vi¬ sual failure at the time the diagnosis was made.3 However, no details con¬ cerning the three of 56 patients with
presumably normal
visual acuity can be extracted from the report. The im¬ portant point that has been recog¬ nized, but not emphasized, is that gliomas infiltrating the optic nerve may rarely have no clinically detect¬ able decrease in visual acuity or color vision. In retrospect, more detailed tests such as pupilography, visually evoked cortical response, more exten¬ sive color vision testing, and determi¬ nation of modular transfer function might have disclosed some afferent defect of the right optic nerve. There may be a relatively pro¬ longed course of tumor growth of op¬ tic nerve gliomas, during which time vision is not affected. As these slowly infiltrative tumors expand, they grad¬ ually separate and distort the longi¬
tudinally arranged axons, yet many functioning axons undoubtedly sur¬ vive for a long time so that they are seen microscopically to have an unin¬ terrupted anatomical course through
the midst of the tumor. Vision ulti¬ mately fails with chiasmatic and op¬ tic nerve gliomas as the tumor bulk continues to disturb anatomical-me¬ chanical and vascular needs of the anterior visual pathway. However, in the case of many optic nerve gliomas, another reason for ultimately failing vision may be that of compressive force on the nerve within the optic ca¬ nal. As the tumor slowly grows within the restricted confines of the optic ca¬ nal, it exerts force both centrifugally and centripetally: bony erosion occurs externally and demyelination occurs in the nerve. Eventually, there is disruption of axis cylinders. Enlarge¬ ment of the optic nerve has been at¬ tributed to accumulation of muco¬ substances,7 but morphologic and histochemical evidence of the pres¬ ence of such substances was absent from the present case. Rather, the en¬ largement resulted from infiltration
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
and replacement of the nerve by as¬ trocytes and their processes, along
with some thickening of the connec¬ tive tissue septae. Surgical removal was selected in this case because of the radiologie and anatomic evidence of tumor exten¬ sion to within 1.5 mm of the optic chiasm. We are aware of the mean¬ ingful controversy surrounding the treatment of optic nerve gliomas, but we believe that a discussion of this complicated subject is beyond the scope of this presentation. This patient became symptomatic with the abrupt onset of diffuse head¬ aches. At surgery, we found an en¬ larged optic nerve with inflammatory adhesions between the hyperemic tu¬ mor within the optic canal and the surrounding durai sheath. It is pos¬ sible that this child's optic nerve glioma was diagnosed before vision began to fail because early durai in¬ volvement led to pain and headaches.
Robert Helper, MD, assisted in the prepara}n of this report tion report.
References 1. Walsh FG, Hoyt WF: Clinical Neuro-Ophthalmology, ed 3. Baltimore, Williams & Wilkins Co, 1969, vol 3, pp 2076-2094. 2. Verhoeff FH: Primary intraneural tumors (gliomas) of the optic nerve. Arch Ophthalmol 51:120-140, 1922. 3. Chutorian AM, Schwartz JF, Evans RA, et al: Optic gliomas in children. Neurology 14:83-95,
1964.
4. Udvarhelyi GB, Khodadoust AA, Walsh FB: Gliomas of the optic nerve and chiasm in children: An unusual series of cases. Clin Neurosurg
13:204-237,
1966. 5. Jummelt K: Spongioblastoma des nervus opticus mit guter funktion des auges. Klin Monatsbl Augenheilkd 125:591-594, 1954. 6. Dodge HW Jr, Love JG, Craig WM, et al: Gliomas of the optic nerves. Arch Neurol Psychiatr 79:607-621, 1958. 7. Anderson DR, Spencer WH: Ultrastructural and histochemical observations of optic nerve gliomas. Arch Ophthalmol 83:324-335, 1970.
