Journal of Neuro-Ophthalmology, June 1981, Volume 1, Issue 2

Radiation therapy for primary optic nerve meningiomas.

Optic nerve sheath meningiomas, formerly thought to be rare, have been encountered with surprising frequency since the widespread use of computed tomography. Early diagnosis led to an enthusiastic surgical approach to these lesions, but this has been tempered by the realization that even in the best of hands, blindness followed such surgery with distressing frequency. Optic nerve sheath meningiomas may be divided into primary, secondary, and multiple meningioma groups. Five patients with primary optic nerve sheath meningiomas treated with irradiation therapy are presented in this report. Improvement in visual acuity, stabilization to increase in the visual field, and decrease in size to total regression of optociliary veins, have been documented following irradiation therapy of the posterior orbital and intracanalicular portions of the optic nerve in some of these cases. Although each patient must be carefully individualized, there is no question that visual palliation can be achieved in some cases of optic nerve sheath meningioma. Further investigation of this therapeutic modality in selected cases in advised.

f. Clin. Neuro.ophth~/mol. 1: 65-99. 1961. Radiation Therapy for Primary Optic Nerve Meningiomas ). LAWTON SMITH. M.D. MARIO M. VUKSANOVIC, M.D. BASil M. YATES, M.D. DON C. BIENFANG. M.D. Abstr~ct Optic ntrvt shulh mtningiom~!>,formtrly thoughlto bt rut. h~vt bftn tnCounltrtd with surprising frtqutncy !>incl' tht widnprt~d ust of compUltd tomogr.lphy. [~rly di~gnosis ltd 10 ~n tnlhusi.astic surgiul ~pprQ.lch 10 Ihtse Inions. bUllhis hu btl'n ttmptnd by Iht ruliution Ih~1 tvtn in tht best of h~nds. blindnns followtd such surgtry with diSlrnsing frtqutncy. Oplic ntrvt shuth mtningiom.lS m~y bt dividtd into prim~ry. SKond.lry, .Ind multi pit mtningiom.l groups. nVt pdtitnts with prim.lry optic ntrvt sht.lth mtningiom.as trutl'd wilh i".di.ltion thtr.py.lft prtsenttd in thi!> rtporl. Improvtml'nt in visu.1 ~cuity, st.lbiliUlion 10 inCTt.lst in tht visu.1 fitld, .Ind dKrust in siu to tot.ll rtgrnsion of optocili.ry vtins, h.vt btln documtnttd following i".di.tion thtr.py of tht posll'rior orbit.l .nd intr.lun.licul.lr portions of tht optic ntrvt in somt of thtse uses. Although t.ch p.ltitnt mu!>t bt urtfully individu.liud. thtrt is no question Ih.t visu.1 p.llli.tion un bt .chitved in some U!>i'S of optic ntrvt she.th meningiom•. Furthtr investi~tion of Ihis ther.ptutic mocblily in stlKted uses is .dvised. Optic nerve she41th meningiom41s. previously considered to be r41ther r41re.''"'' h41ve been encoun· tered with surprising frequency in neuro·ophth41l. mologic pr41ctice since the widespread use of com· putI'd tomogr41phy.t..7 Early diagnosis led to an enthusiastic surgic41l olpprOdch to these lesions.~but this has been greally tempered by thE' subsequent realization thai even in the best of h41nds ,md USlllg from Iht 8.Kcom r4lmtr [yt' 1",>!,lul('. [){"p.ortm<'nl "f nph. Ih.ilmoto,:y, UnlV~""ly of M'4m, xn....... "I Mcd,,·,n('. l)('p.on. men! of Tht...ptullr R..d,olo,(y. (cd..!'!> ..f lro..non M<od,r..l Ctnltt; tnt Dtp.lnmt"l of NtU'..IoUI)t{"ry. H''''(,4h Hosp,l..1. M;.Im,. rJond.l. 4nd Iht Ptltr Bt"1 8"lth4'" H."p'I.. I. Bo'>lon. M..surhulottls. Junt 1981 edreful miCfOSUT);ic411 technIque. postopefdlive blindness occurred with distressing frequency.~· '" In the firsl reported case of visual recovery follow4 ing surgical removal of such 41 tumor, II Ihe men· ingiomd arose prim41rily in the orbit dnd 5E'cond· arily surrounded the optic nerve shedlh. Subse­quently there hdve been d few other U5E'S fdvordbly mdndged by .I surgical dpptOdCh, but the mdndge­ment of these tumors still cOnstitutes d difficult decision. This is becduse the smdll pidl blood ves­sels of the optic nerve drt' so intimdtely involved in shedth meningiomds that often it hdS been impos­sible 10 dissect the5E' lesions from the intrdvdgindl spdce without resultant infarction of the nerve. Menin~iomds hdV(' been generdlly considered 10 respond poorly to rddialion therapy.'~ M,my cli­nicians, therefore, hdve elected simply to follow these cases. However, there hdve been sufficient reports of efficdcy of rddidtion Iherapy for menin· giomds':l· " to Wdrrdnt COnsideration of such ther· dpy in selected instances of th('se tumors. We quite .l~ree with the import,mee of differenti.llin~ pri. mary optic nerve shedth menin~iomdS from those second.trily extending into the n('TVe. .IS noted by Wri~ht et dl.,l!. and also in ('.lses with multiple meningiomds. Rddidtion thcrdpy hdS bel"n l'mpl~ly('d in st>!t'cteJ inSldnces of optic neTV(" sh("dth m("nin~"lm.ls in ~lur prdctice since IQ75. Document.ltion of thl" rt'sults in five pdlicnls with optic nerve she.lth menin· ~iomds is Ihe subject of this report. The results of irrddidtion therapy in S('("ond.lry optic nerve shedth meningiomds, or with multiple m("ningiomJs. will hl,th(' subjl"~·t of .mother report. T(l our "n(lwled~e. tht' followin~ C41seS .lre the first repl'rted insldnces of rddidtion Iherdpy for oplic n('rve shedlh men­in~ iomds. Case Reports Cd5f' I (A.B.) A 61·yedr-old right.hdnded white m41rried woman WdS first S«n in 1975 becduse she W41S 85 "wt'rried ,1bl'lIt visitm in thl' left eye," Shl' .llwdys Ih<lu~hl IhC' left eye d bil we.lker th.1O Ihe ri~hl eye, bUI by [.JnU,lry IQ75 she re.lli7.ed Ihdl thC' vision W.1S definitely less in Ih(' lefl eye, ntlled .1 "veil"' diffusely <lY('r Ihl" (,Iltire fil'ld of Ih,1I eye, dnd vollinil'ered th.1t n'd t,bjt'cts W('f{' not ,1" vivid with Ihe 11'(1 ('ye, There \\/.Is nil p,lin on ('y(' Jll(ltion, no hl'.ld.ll'hC', .md no,'IIll'r tlC'lInll,,~ic compl.lint. Ex..lmin.llil'n nn M.lrch 20, IQ75, n·vl'.!!ed ,I cor~ rected .Kuily <If 20/15-2 in Ihe righl ey(' dnd 20/ 20-1 in Hw I('fl eyc, The p,llpC'br,11 fissur('s me.!· surl'J JO mm lln Ihl' ri~ht dnd II mm on thc left, The pupils were 4 111m on the ri~ht .!nd 5 mm on Ihe left. There W,lS .1 3+ MJrcus Gunn J.ffercnl pupill.lry re.lclion in the lefl eye. Ex.oplh.llmomelry reve,lled 2-mm proplosis of Ihe left eye. Visu.ll field ex.,lmin,llion W.1S norm,ll in Ihe righl eye .!nd r('veJled d very sligh I lower nJsJI conlr.lction in the left eye. The right optic disc WdS norm.al. but Ihe lefl disc w.as blurred .Ind h.ad elev.ated m.argins (Fig. 1.:1). The drlerioles were ndrrow but no hem­orrh. ages were scen. Becduse of the slighl .lsymmetry of her eyes, old photogrJphs wcre reviewE'd. A picture m.ade in 1942 substolnliJ.ted the fJcl Ihdl her dppe.arolnce hdd not subsequenlly ch,mged. Becduse of this photo­~ rdph, x-r.IYs were not ordered .It tholt lime The clinic.Il impression WdS belween dtypic.al ischemic 1·>1 optic neuropathy, Ihyroid exopthalmos, and a left orbital meningioma, She was found 10 have mild didbetcs mellitus, and was sent back 10 her private ophthalmologist with careful follow-up advised. Four years later, the patient was referred back bccduse of a further drop in left eye vision. She had noted .I slow, steady drop of acuity in the eye during the preceding 6-8 months, and could no longer tell colors with Ihe eye. She was taking 16 units of NPH insulin d.lily, was under good control, dnd h.ld no other complainls. EX.lmination on April 16, 1979, revealed a cor­reeled dCUity of 20/15-2 in the right eye and 20/ 80+ I in the left eye. A profound loss of visual field had occurred in the left eye (Fig. 2). There was now d 3-mm proptosIS of the left eye. One look at the fundi established Ihe diagnosis for classic optoci­JiMy veins" were evident on Ihe lefl disc (Fig. lb). It was .lppMenl that the patient had an oplic nerve meningioma on the lefl. Roentgenograms of skulL optic can.als, .lnd computed tomography (Fig. 3) confirmed this di.lgnosis. After discussing the mat­ter with the p.atient, it was elected 10 treat the left optic nerve with radiation ther.lpy. Supervollage radiothera py tre.llments to the pos­lerior one-third of Ihe lefl optic nerve were given bE'twet'n MolY 7 and June 25. 1979. Two par.lllel coplandT opposing portals were (0) liKU'" I. c" I dl "pi" J,,, "' <.1,," 1 III M.",!> 1"'7~. b"I",,· J"V"I,'pm('nl,'f <>plllciliuy Y~;ns. (b) l~ft optic dis.:: of C;lSl' I in April ''''7''. '" _t.. "I"'~ oI'.'rv Y,'"'' .'1 ~ .,,,d 4 ,,', I, ... l. Journ.ll of Clinic.al Neuro-ophlhdlmology Opu.to, _..oj_I_.__ Ton 0 b 10 et. _...,)",1,,)_),0_",...1_'1;;,.1;;,..:....,-,,..-.,­ «(1) inl <c Aimork LE. a 20/~u+l 'IlaI,a J t VISUAL. FIE1.CS \perlPh,aO (Ca.lral) R.E. Smith, Vu"~"n(lvic Y~t", ,Bienf~ng Date __4_'_10_-_7_9 _ Ta II ob j .. 1.._)~/~):")'"i0e:-:"",h~l~t",e":"';"=:r._ (0) Inl sc Aimork ~F.FORE IRRADIATION THERA PY cc 20/l5-l YIlio. _~I~,~ _ June 1981 Figure 2. \',~ual firld. "f l~~r I bd,'rr radi"thrr.,py. Figure 3, Compulrd IllmOl\raphic sCan (rd r meningioma. 87 R.ldi.ltion Thl'r,lpy for Optic: Ml'ningiom.ls USE'd to give 2oo-rad incremE'nts for each treatment session over the 5-week course. A total tumor dose of 5300 rdds was given to the left posterior orbital dnd intr.lcanalicular optic n«rve. Within 10 days of beginning the therJpy, vision began improving in her [eft eye. The d,ly ,lfter finishing the course of radiotherilpy, i1cuity W,lS 20/50+3 in the left eye ,llld the ViSU,ll fiE'ld WilS over three times as largE' as prior to treatment (Fig. 4). InterE'stingly enough, thE' shunt vessels in the lE'ft optic disc WE're smaller the day Jfter radiotherapy had been concluded (Fig. 5). On July 12,1979, she h...d 20/40+1 iicuity in the lcit eye and volunteered that whereas shE' hold only been able to see in "black and white" before radiotherapy, she chould now detect "blue .md yellow" colors in the lcit eye, but still could not appreciate red and green in the E'ye. Four months dfter treiitment, vision was 20/50+2 in the left eye, and the field was unchanged from thdt seen in Figure 4. The patient returned on October 7, 1980, with no compliiints and considered that her vision WdS stablE'. Dr. Jdmes Mitchell examined her in our officE' and found the corrected acuity to be 20/ 20+3 in the right eye iind 20/50+2 in the left eye. A ciireful visual field eXdmination revealed that the inferonSiiSdl arcuate SCotomd breaking out of the blind spot appedred to be sm... lJer and less dense than had been noted 10 months earler. Exophthal­mometry revealed 2-mm proptosis of the left E'ye. Ophthalmoscopy revealed that the left optic disc was markedly pale with attenuated vessels on thE' surface, but the optoci[iary shunt vessels had com­pletely disappeared (Fig. 5c). Comment: A 61-year-old woman presented with a swollen left optic disc, 20/20-1 vision, and a modest lower nasal field defect in 1975. Four yeiiTS Idter, she returned with acuity down to 20/80 and a profound loss of visual field in the involved eye. Classic optociliary veins (the Hoyt-Spencer signl were now present. A course of radiation therapy was given to the left optic nerve. Within Z months, iicuity improved from 20/80 to 20/40, the visual field enliiTged 10 at least three times its former size, and the shunt vessels became much smaller. A comparison of the fundus photographs confirmed that the latter was not due to a general decrease of disc vascularity, for whereas the optociliary veins became notable smaller, the other vessels travers­ing and surrounding the optic disc remained un­changed in size (Fig. 5). She noted color vision beginning to return in the eye within 2 months of radiotheriipy. Four months after treiitmen!, the im­provement dppeared stable, and this stability was miiintained at a follow-up 16 months postradio­therapy. C<lse 2 (E.o.) A 63-year-old womiin was first seen in 1975 because of poor vision in the left eye. She hold no eye problems until 1963, when she developed a retinal detdchment in the left eye, operated suc­cessfully in New York. In 1966 a retinal detachment occurred in her right eye, and again she was op­erated and did well. She had no further complaints until December 1973, when her daughter men­tioned that the patient's left eye appeared a bit OP... to. __-'j-ls"- _ T ... obj .. II --'~1~'""!'2..0"~"~."'= (0) lot $~ ......uk VISUAL FIELDS (P.,lp""O flnhh~d 26 ,not_nto udlolh<,upy ~~~~~~~~'l!:~" to left optIC "H~" ~utud.y '" Dot. 6·26·79 _ T...."j .... 3/]]0 ""i,.. (0) Int ,C Aimo,k ~ITER IRRAD'ATIOll ~ " yLol... _c'1'0,I"'~5-C''___ ].[ Journal of Clinical N{'uro-ophthalmology Smitn. Vuksdnovic, Ydtes, Bienfdng ibl June 1981 ('J Flgur~ 5. (.. I Left optic disc of use on" on April lb. 1979. (b) Left optic di~' "f case I on June 16. 1910. Note the optocili"ry v('ins h,,"e become sm"lIN "ftN radiotherapy. although th(' other v('5sll'ls hdve not ch"ng('d in size. (,'j left optir d,sc of CdS(' 1 on Octob('r 1. 1980. 16 months dher rddioth('fdPY the optocili"ry vll'ins hdVC disappeared. " R.IJi.\tion Th('r.lry fur Optic Meningium.l~ TABLE l. Corrected Visual Acuities (Case 2): Before, During, and After Radiotherapy 1·20-75 20/20 + I Hand movcml'nts 2-28-75 20/15 - I Hand mOVl'ments Radiation thl'rapy to left optic neNe 3·4-75 to 4-11-75 4- [-75 20/15 - 2 61200 9-19-7S 20/20 + 1 20/80 + 1 10-12-76 20120 + 1 20/50 + 1 8-30·77 20/20 + 1 20170 - 1 8-15-78 20/20 + 1 131200 8-14-79 20/20 + 2 10/200 8-19-80 20/20 - 1 71200 prominent. In April Iq74 the left eye VISion was definitely less, .md routine skull x-rays were made <lIld reported as norm.11. A course of steroids was given ill December IQ74 without relief. Ex.1mill.lIillll on j.1Il1l.1 ry 13, 1Q75, revealed a c\)rrl;'cted .Kuity \)f 20/20+ I in the right eye and hJnd lTIlWCnwnts in thl;' left eye. The left eye was proptosed b mm, showed a 4+ Marcus Cunn pupil, .lnd the left disc WJS swollen Jnd showed devel­l) ping p.1110r. But for peripheral buckles in both eyes, thc fundi were otherwise normal. Skull roent­gl;' nogr,1Il1S, optic CJnJI tomograms, ultrasonogra­phy. orbital venography, and a computed tomo­graphic scan were performed and confirmed the clinical impression of a left optic nerve sheath meningioma. Radiation therapy was given to the left optic nerve between March 4 and April 11, R;~ht Eye Vis;"n left Eye Vision 1975; 2000 rads were given by linear accelerator by a straight perpendicular portal and then 5220 rads by lateral portal. Visual improvement began within 3 weeks, and steadily improved in this eye during the next 18 months. The patient's corrected acui­ties- before, during, and after radiotherapy-are seen in Table 1. Visual fields before and HI! years after radiotherapy are seen in Figures 6 and 7. A computed tomographic scan 3 Jh years after radio­therapy is seen in Figure 8. Differences in tech­nique made exact comparison of the computed tomographic scans difficult, but the mass appeared essentially unchanged in size in the 1975 and 1978 scans. The tumor appeared perhaps slightly larger in the 1979 scan. Comment: A 63-year-old white woman pre­sented with vision reduced to hand movements in the left eye due to a clinically diagnosed primary optic nerve sheath meningioma. After irradiation therapy, visual acuity improved from hand move­ments to a maximum level of 20/50 in this eye over the following year and a half. The visual acuity and field maintained improvement for at least 2 years, and then a slowly progressive sub­sequent deterioration occurred during the third, fourth, and fifth years after irradiation therapy. The vision at that point, although poor, was still better in the eye than it had been before therapy. Case 3 (f. W.) A 42-year-old white woman was first seen in May 1977 because of unilateral papilledema in the left eye. She presented to her physician with a history of headaches for 5 years, hypertension for 2 years, and difficulty focusing at near with the left Opttotor __J..,·1"'5 _ o. to _...:.:Ja:.::n:.:.u:.;ary~.:::20:..!.:.....:.19.:.:7..:S _ ToU oblo." 10/330 white (0 int sc) C1x1ng on finger I.E. BEFORE iWiiOTHERA P"1' VISUAL FIELDS \potlpltoroll R.E. 31330 white To.. 010 Ie C I LO......,(~e-.·..'~'t_se.-j)-..'...~_.,.11o-- s:....£.. Poor LEV R!Vcc 20{20+1 (J-l) VIoIOD _ Journal of Clinical Neuro-ophthalmology 0,••• t •• _--,I~hL.__• • _ VISU"A..L,'.F..I.ELDS ~ " 'Ito I .. _"'e',-,"':::'c'-, T.....1.... JIll!) wid'" o Inl .c AI-.1rk I' ~~. A,OIl' MP,·r!l!t..v.ry- 1,,0 ",Uc •• ",. " Vh I.. _-'''''"'.',--_ Fi\l:"''';' \ "u~ll1dJ. ,'1 .~ ... : I! ,.....,•.,ilt·, ' ..J">lh("'~I'V Th(" 1'<',,!'h("... J f,("ld .h~"Jo:(" ,n Ih(" ftio:ht "'... ,,~......."'J...... h' .. " ... ~Im~ "f"r'~I1.", I." '<"lm..1d("I~,hm'·"1 J .. fjg".~ 8. c."mpu,,·d I,,",,-.:r.>ph .. " .." "I •.1...· : .h",,''''': Idl ..,.... " •. ,.,.....h,·.llh m("n,"j(,,,m~ J; Y""" ~fh" 1"••J,..h"" lh'·'.lf''' eye ,md flashing lights in the outside p.H1 of the' left eye vision for I month. Ex,tmin,J1ion rev('.ll('d unilateral papilledemd in the left eye, .md she IVJS hospitalized in Fort Myers, Floridd. Skull x-r,lys. computed tomogrdphic scan, lumbdr punclure. ,md bilatefd[ carolid drteriography lVere .111 r{'ported .IS June 1981 m'rmJ!. The Il1lpr('';~I,'n ,'n d,S(h"~,, 1V01S unildt_ er,11 p,lpill"J"OlJ..r th" Idl "y". h",ld.Khes .,f pos­~ ible VJS(UI,lr {'tillk.~y ..lIld lhJt she IVJS under Ir{'oHm"nt for hypertensi,lO. ShE' 1V,1S ref('fred to the B,IS(llOl ('Jlmer InSlitul(' bec,ulse (If th(' unildl('fJI p,lpillcdcm,l in h('r lefl cy('. 9' Rddidtion TkerdPY for Optic Meningiomds Examination on May 6, 1977, revealed 20/15 acuity in both eyes. The eyes were white, pupils reacted crisply to light, and only a slight pupillary escape could be seen on the left, which was not considered sufficient to even call as a 1+ Marcus Gunn pupil. Krahn ex ophthalmometry at base 89 was 18 in tke right eye and 18-18.5 in the left eye. The peripherJI and central visUJI fields were nor­mal but for slight blind spot enlargement in the left eye. Ophthalmoscopy disclosed a nonnal disc in the right eye with d good spontaneous venous pulse; however, the left disc WdS definitely choked (Fig. 9<1). The veins were distended, no sponta­neous venous pulse was seen, but the vein could be collapsed by pressure on the lid. Ultrasonogra­phy was performed and said to be consistent with a peripheral lesion in the left optic nerve sheath just behind the globe. Follow-up was advised. She returned 5 weeks later and now gave a kistory of transient obscurations of vision in the left eye only. Visual acuity was 20/15 in both eyes, but a I + Marcus Gunn pupil was seen on the left, the left disc now had one or two small hemorrhages on its surface, and the visual field had definitely changed in that a lower nasal arcuate defect was now found in the eye on both perimeter and tan­gent screen. The patient was also seen by Prof. E.W.o. Norton, and optic nerve sheath exploration was advised. A repeat computed tomographic scan showed that the left optic nerve sheath was wider than the right. The patient was hospitalized, and on June 22,1977, the left optic nerve was explored by Dr. J.D.M. Casso A nasal approach was used, and visualization of the anterior part of the left optic nerve appeared quite nonnal. A small inci­sion was made in the sheath, and a little bit of whitish material came out but no fluid. A small biopsy of the sheath was perfonned and reported as nonnal dura. A follow-up visual field postop­eratively (Fig. 10) showed no notable change from the preoperative examination. The patient was ad­vised to be followed by her ophthalmologist. She was followed regularly at home and visual acuity remained stable in the left eye during the next 3 years. Because of experience with similar patients, an optic nerve sheath meningioma was suspected in this patient and she was recalled in February 1980. Examination on February 15, 1980 revealed a best corrected vision of 20/15+2 in the right eye Ib) Figur.. 9. (d) C~'(' J-Idt "pt,,· disc in 1"77. (b) CIS(" 3-ldt optic disc in b<>F d (...flOW_) 1980- ore ra ioth("rapy. Note optociliary veins Joumal of Clinical Neuro-ophtkalmology Op... to, __t!·_. _ O.t. Smith, VU"~Jn"vlc, y"te~, BienfJng 7-S-77 T. u ob ,_ e" --,1,.;./..3..".30--.--:w:--.h,..,l,..t."..."....__ (0,6 tnt j SC' Aimllrk I.E. Viai,o ~O'2()-1 VISUAL FIELDS o-er I phera I) R.E. TeU obj •• " 1/330 white (0.6 tnt) sC A!mark ....p r.t ..d !!.:11-:11 ST-OP Viai,o 20/1S-1 Figun 10. Visu~1 fields of c~se J on July 5. 1977, Operator__j l~__ . Oat. 2_-_1_5_-8_0 _ Tel" (aJlcu -~ 10/330 white Oint sc Xi...k L.Eo VISUAL. FIEL.DS o-erlphe,.U T.. t ob joelL-r3 'To3..,3...,0....wh='r·t_e _ SInO red Oint sc Aimark /l.E. ?Ill: iW)iAT! ON THERA P'Y vfitoo __20_1_1_5+_2_ Flgun! II. Visu~1 fields of c~se J on Febru~ry 15. 1980, Not<' <,~lreme loss of fi<'ld in tht' It'ft ('y<' sin.:t' 1077 (Fig. 101. and 20/30+2 in the left eye. There was a 2.5+ Marcus Gunn pupil on the left. Exophthalmometry at base 92 was 18.5 in the right eye and 18 in the left eye. Visual field examination was normal in the right eye, but a dramatic loss of field had occurred in her left eye, and only a small upper nasal island now remained in this eye to the largest isopters (Fig, 11). The left fundus now established June 1981 the diagnosis immediately for classic optociliary collaterals were seen (Fig. 9b). A repedt computed tomographic SCdn on the General Electric 8800 scanner revealed a diffuse optic nerve meningioma on the left (Fig. 12). Optic canal complex motion polytomography revealed no evidence of hyper­ostosis, bony erosion, or enlargement, and the impression was normal optic canals. 93 R"di"li"n TI",r.,py tor t 1pl i,' M'·Jlill~i"m.,~ After di~(tl.,.~ion, ,I ,','urs(' of rJdillthN.:Jpy to the ldl ,'plir n('rv,' WJS ,IJvist'd. The p.l!ienl r('ceiV"d .1 t"ltmul.ltivl' J,'M' "f Jt>OO r"ds to Ih(' I,'fl 'lptic nerve in :!OO-r.1J fr.ll·lioIlS bt'lWl'['1l M.Hch 5 ,md :!~. 1<1130. [>••1Il1in.1ti'1Il ,'n M.Hrh :!5, .Cj~O, rl'v(',llt·d.1 cor­rl'd,' d .1ruily 'If 20/20 slowly in the I,·fl l'y(' Jnd J ver>' .,.Iil-:hl Ch,llll-:" W,IS S('('11 in Ihe visUJI field (ri~. IJ,;). By huH' 17, 1')00, the sn1.111 upper nJsJI remn.llll "f fi"IJ in Ih(' kft l'yP h"d inrr(',lsed slightly in silt' On September :?oj, Itl130, corr,'ct('d ,lruitv W,lS :!O/15 in the rightl'y(, ,md 20/20+2 in lh,' I'efl "ye. The visu,ll fidd WJS very slighlly impmvt>d in Ih,> I('fl "ye (Fig. I3b). The lC"ft disc W.1S p,lle Jnd the optociliJry shunts JppeMed 10 be ber'lmin~ slightly sm,ll1er. Comment: This 42-yeJr-old wom.m developed .1 unil.ItPrJI choked disc thJt remdined undiJgnosed dC"spite lleurorJdiologic studies Jnd even orbildl surgicJI inspection of the optic nerve sheJth, until profound loss of field, developmenl of oplociliJry shunt vessels, Jnd an overwhelming computed tomogrJphic scan finJlly confirmed early clinicJI suspicions. Roldiation therdpy was followed by only minimdl improvement in the vi SUd I field, bUI visudl dcuity did improve from 20/30+2 to 20/20+2 within b months Jfler tredlment. Case 4 (O.K.) This 59-year-old white womJn WdS firsl seen in Aus.;ust 1979. Her chief compldinl was, "I'd like to get my right eye vision back." She had no com­plolints unlil 1974, when tr':lIlsient obscurations of vision begdn in her right eye. In March 1974 she WdS told that the optic nerve WdS swollen and was tredted with steroids. Neurological examination, skull x-rays, dectroencephdlogram, and lumbar puncture were all normal. The patient did rather well in 1975, but in 1976 the episodic "blackouts" recurred in her right eye. PerioculiIT steroid injec­tions on the righl again gave some Iransient im­provemt> nl. A fluorescein angiogram was per+ formed in June 1975 and small shunt vessels were described on the surface of the right disc, bUI these were not thought to be optociliary collaterals by the eXdminer. Ultrasonography in New York in October 1977 revealed evidence of perioptic en­IJrgement of the optic nerve immediately behind the right globe, and the pOSSibility of perioptic meningioma was raised, bUllhe ultrasonogram was nOllhought 10 be conclusive. Corrected vision was 20/20-2 in the right eye in June 1976-20/30+3 in September 1977-wils down to 20/200 by June 1978, fell 10 finger counting within a few weeks, dnd by the fdll of 1978, she lost all vision in the right eye, She had seen no light with the righl eye for 7-9 months before eXilmination. But for very slighl recent discomfort dbove this eye, she had no other complainls. PJst history revealed known hy­pertension since 1970 and a benign thyroid nodule was excised in 1977. Examination on August 3.1979, revealed no light perceplion in the righl eye and 20/15 in the left I iKU'" 12. t""'I'''Il'd t""'''):'.'l'hi,· ~,'.,,\ "f '.Is.. '\ on 2·14~80 $howiflg left optic ". n'" ,h,·.'lh ""''''''K'''O'.', Joumal of Clinical Neuro-ophthalmology Ope.lto, __1_1_5 . _ Dol. RE 1-11\-1<0 LJ:: • 1-25-110 VISUAL FIELDS tl""I'~.tllJ T.. t obitet. 1/310 whiU 11 int sc AimaTk LE, Ope .. tor -"-j.;::.\5:.- T.. t 0 blee to _--,I;.:0'!c/.:<3=3.:::0_wh::.:..:.i~t~e=--_ (0) Int 5e Al.Jnark .JI_~, !Cntrl.) (,II VISUAL FIELDS (peripheral) 4 radiatiOn therapy IrClilments to this ~lIte _A wi 11 finish ',-21<-1<0 with II< VI.loD _2_0_/_1_5 _ 01 I. __S_e_p_t_,_2_3_,_1_98_0 _ 3/330 white T eHobj eel "-T1(Orrj"iirn"t"'<src--='A"'iTTl8l!!JMt"'kr-- se VI,loD Cc 20{ 0 20/20+2-3 I.E. (C.DI,.I) ft.) IU. ~ix months post Tadiot~ 0600 rods left .:pt Ie nerve Completed 3-28-80) sC 20/15-1 V1~ i OD __2_0_/_1_5__ Figure 13, (d I elSe )-vlsudl field of left eye "n 3-25-110 (b I C. .N' 3-vi'u,,1 (,,,Id "f Idl .'v,' "11 "-2.'-:10 ,h",," slil:hl improvement In fIeld 6 month, Jfter rJd",therJpy. e,mp,,,,' wllh r,;;, II 1>.'1<"., In',lln","1. eye, The right lids were puffy, the eye WilS prop­tosed 3 mm, iI beginning sensory right exotropiil WilS seen, and the right pupil was amilurotic. Visuill fields were normal in the left eye. A conjunctivill pigmented naevus was seen on the upper nilSill June 1981 limbus of the right eye which hJd not ch.mged in the previous 25 ycars. The left ()ptic disc was normal, but the right disc W.1S slightly swollen, quite pille, and showed a suggestion of shunt ves­sels off the lower temporal margin. A General 95 Electric 8800 computed tomogr.lphic SCJn revt'.:IIt'd typicJI chJnReS consistent with J ri~ht orbit.:ll optic nE'rve she.lth mt'nin~iom.l. There JppNred to be no evidence of intr,lcrJni.ll extension of this lesion. After CJreful consider.ltion, .Ind l':iving the pdtient .Ill t'ssenti,llIy hop('I('sS prognosis for vision, irrd­di, Jtion tht'r,lpy W.lS e]ectt'd with the primdry .:lim of Irt'Jtmt'nt being 10 reduct' or ret.ud intrilcrdni.=tl extension ,)f thl' Ill('ningiolllil, The p.:ltient received .I tot,11 dos(" of 4140 r,lds to the right optic nerve in 23 Ire,lllllent s("ssions in August IQ79, She return("d for .I follow-up on August 19, IQ'W-I yeJr ,If!(''r completing the rJdiother.=tpy. UnfortunJtdy, the right eye WJS still blind and h.=td .In .lm.lurotic pupil. The piltit'nt reported that tht' tenderness Jbout the eye hdd disappeared and she thought it WdS less promint'nt. Exophthalmomelry rev(".lled 2.5-mm proptosis of the right eye. The visUJI field was normJI in the left eyt'. The right eye was white Jnd quiel .:Ind showt'd no extern.:ll evidence of rJdidlion d.:lmage. The right disc W.:lS quite pale with an optocilidry vein at 6 o'clock and the left disc was normdJ. Rept'at skull x-rilYS, optic canal polytomes, and a rt'pedt General Electric 8800 computed tomogrilphic sCiln revealt'd no definite changes from thost' mJde 1 yeJr edrlier. The chi.lsm drea and sellJ dppeared cleJn and the pa­tient was advised to return in I yedr for repe.:lt complex motion bJse view optic canal polytomog­raphy. Commenl: A 54-yeu-old woman developed progressive pdinless loss of vision in the right eye in 1974. InitiaJJy she had transient obscurations of vision in tht' eye, which transiently responded to periocul.:lr steroid injections. The response of men4 ingiomas to steroids has been noted not infre­quently by other authors and needs to be remem­bered. However, despite extensive neuroradiologic studies, the definite diagnosis was not made until after the eye had become totally blind. The deci4 sion to irr.:ldiate the optic nerve in this patient was certainly open to deb.:lte, but it W.:lS hoped that even though vision probably would not return at all, the chance of reducing the likelihood of intr.:l­cranial extension might be more reasonable. One year after radiotherapy, although the eye remained blind, the patient reported that the eye was no longer tender to touch, there had been no progres­sion of proptosis, the sella and chiasm area ap­peared clean on repeat computed tomography. It will require ddditional protracted follow-up of this patient to prove whether or not intracranial exten­sion of the meningioma has been prevented. Case 5 (M.R.) A 51-yeilr-old white woman was first seen at the Pt'ter Bent Brighdm Hospital in Janudry 1975 com­plaining of field loss and blurred vision in the left eye. Examination at that time revealed a visual acuity of 20/20 in the right eye and 20/60 in the left eye. An afferent pupil defect was evident in the left eye, and the left disc was atrophic. There was a loss of temporal field in the left eye. Arteriogr.:lms Joumdl of Clinical Neuro-ophthilJmology rijtur~ I~, CJ"- ~-klt "1'1'" .;I", "ll ...·I~·;~. ,-":,'1.' .'pl".'''Jry ",'on" 1Jrr,',,",1 d,lne dsewhere were normd!. bdsJI tomo~rdms rdised J question of bony er.:lsion at the entrJnce or Ihe left optic canJI. and a computed tomogr.lphic scan was reported as normd!. The p.ltient's left eye vision continued to drop, .lnd she WdS hospitdlized in MdY 1975. Orbit.ll ullrJsound reve.lled an enl.lrged left optic nerve. lumbu puncture and pneumoencephJlogr,aphy were normdJ.ln September 1975 d repeJt computed tomogr,aphic SCotn WdS normJI; however. field loss continued J.nd visu.ll ,acuity WdS down to finger counting in her left eye. A repedt computed tom­ographic SCdn in December 1976 (Fig, 141 suggested dn intrinsic lesion of the left optic nerve. By June 1977 bdse polytomes suggesled thdt the orbitdl portion of left optic candl was enlarging. A left frontal craniotomy WdS performed in Bos­ton in September 1977. A mass was seen ext('ndin~ out of the intracranial end of left optic canal on to the durd, and biopsy of this revealed a "trdnsitional cell meningioma." The patient WdS given d post­operdtive course of 5400 rads to the entire left optic nerve, ,at a rate of 180 rdds/day. In June 1978, 7 months dfler irradiation therapy. Ihe left eye now h.ld no light perception. However, by September 1978 hJnd motions could be de­tected in the left eye. Optocili.lry veins could b(' seen on this disc in ot photograph m,ld{' SeptembN 12, 1978 (Fig. 15), dnd .I repNt comput{'d tomo­gr. lphic SCdn in November 1978 W,lS unch,lnged (Fig. 16). In April 1979 vision W.lS 20/20 in the right eye, h,and motions in the' left eye, .lnd the p.ltient hdd regdined some upper tempordl field in the left eye to IMge isopters. By MdY 1979 tl"lC' optocili,ary shunt vessels h.ld disdppeMed (Fig. 17). In August 1979 the return of tempor,al visual field in the eye W.lS sust.lined. hme 1981 Comment: Thi.. 51-yl',lr-I,IJ whitl' WOlll,ln de­veloped ,l1l ilwxor.,blt· p,linl...ss of vi..iun ,lnd field in her l(·ft l'y~', whirh led I.. ext('n~ivc neuroradio­l,'~ i." inv(,..ti~,llIO'l'o whi,"h WNC unfruilful for sev­I'c. ll YI'.lf... All ,Ipt\l"ih,lry c"IIJt('rdl ve~scJ WdS first seen on the Idt optic di ..r in AUKust 1975. <lnd dt Hdni,ltomy in S{'ph'ml.wc IQ77, bi"p~y r('v{'.lled ,l "tc.msilion.ll n'lI llll·nin~iom.l" .It Ihl' intcJcrdnidl end nf Idl optic .....Indl. The p<Jtil'nl received 5400 rJd~ of irr.ldi.ltion thec,lpy to the lcft uplic nerve pllshlp('rJllvl'ly, Sl'VI'Il monlhs I,ltl'r. the lefl l'ye hJd IW li~ht pcrCe'ption. However, 10 months otftl'f thl'r.lpy, h.lOd movements could be delected with the ldt (,yl', Jnd 17 months ,lftcr irr,ldl,ltion therdpy there W,IS definilely some return uf t('mporotl fi(·ld Figu.e 16. C,'mputtd h'm"l:r~J''''' ,,In "I <~,.... :. m~d,' ('On J I_ 14-7/1 TI'II' ~;,,,ws ...ss... nu.>lIv n" (hJn~... fr"m r,)o: 14 l~ yN" ....rh ....). Figure 11, C~'" 50-1,'(' "I'll< .Ii'" In MJV 1 , .... 1'0.:,'1'" tn ... upl•..:ili"')1 v... ,,,~ >l.... ., on I,):. 150 hJv,' .;I;'~J'r<'M J. 1{,1di,ltiUll Ther.lPY for Uptic M('nin~i"lll,l~ in the eye. Thus, <l sm.11J but ddinite improvement in vision ,md field w(>re documented in this histo~ lo~i(.llly prove'n j'ptic nerve she',lth menin~iom.l 20 nl0nths ,lfll'r irr.ldi.ltion lher.lpy. One could nol .lltributl' this tll the Sll~l'ry, for the' eye W.IS tol.llly l:olind q months Jfte'r the bil'psy, .md the return in visu,ll function ..llbl'it sli~hl, W,IS documented only I ye.lT ,lfter oper.ltion .md .Ihout 10 months ,Iftt'r r.ldiotherJpy. Dis.lppe.lr,lnt·l' of oplocili,lry shunt ve%e1s Jftl'r irr.ldi.ltion tht'r.lpy W,lS JJsI' docu­mented in this C.1St'. Discussion Meningiom,ls involve the optic nerve by two routes. Prim,uy involvement occurs when the tu­mor Mises within lhe optic nerve sheath itsl'lf. More commonly, sl'condJry involvement follows extension of a meningiomd arising from <In <ldja­cent ,lre<l (,lS orbit, sphenoid-ridge, planum sphe­noidale, tuberculum sellae) to surround and com­press the optic nerve. Addition,llly, ilt times in cases of multiple meningiomas, it is difficult to make this exact differentiation. However, com­puted tomogrilphy ilnd complex motion b<lse view optic cilnill polytomogrdphy are now disclosing so many cases of primary optic nerve sheilth menin­gioma that it is evident thill such tumors occur much more commonly thiln WilS formerly recog­nized. It is to the thcrdpy of these specific neo­plasms that we now direct dUenlion. Prim<lry meningiomas of the optic nerve may begin in the intraoculM, intraorbit<ll, intracanalic­ul< lr, or intracranial segments of the optic nerve. Since meningiomds arising within the disc <Ire ex­treme rdrities, they will not be discussed further. The problem in pr<lCtice is usudlly J middle-aged woman who USUdJly presents with p<linless pro­gressive loss of vision in one eye, often occurring over several ye<lrs, in whom <In dfferent pupil is seen in dn eye with minimdl prominence or lid puffiness, dssociated with either slight ipsil<lt{'r<ll disc pallor or slight disc swelling. Th(' subsE'quent development of optociliary shunt vessE'ls on such d disc, subtle loss of dE'lim'<ltion with slight hyper­ostosis of the sphenoid ridge on Cdldwell views, erosion of the optic Cdndl on complex motion polytomogrdphy. dnd In enlarged, thickenl?d optic nerve on computed tomography ,illows the di,l~­nosis of optic nerve ml'ningiomd to bl' m,lde on c1inic,)1 grounds in our experil'nce. The diagnostic triJd of progressiw vision loss, optic disc p.lllor, ,md optocili<lry shunt veins (thl' Hoyt-Spencer sign) in d patient over 20 ye'lTs of .lge is E'sSenti'lt1y pathognomonic for In optic nerve ml'nin~ioma. How should such p.lIients be n,.m.l~ed? [t is evident th.lt this field is in.1 sl.lte of ,lctiv(' eh.mge. MJrk l't aL" did report one p.ltil·nl in whom vision rt'm,lln('~i ,Ifll'r ~ur~ir.ll {'xci~i"n of .m t'ptic nt;>rve rI"'I1'Il~:""".l w,· h"d <'Ill' ~imil.H patient. ,l ZCl_ yeiIT-old woman who prE'sented with a unilateral choked disc for 1 year, and at craniotomy a small meningioma compressed the optic nerve just under the falciform fold of dura at the cranial end of the optic c<lna!. This WdS removed, and the patient's vision hds been stdble at 20/40 for 3 years in that eye since surgery. However, the visual results of surgery on optic nerve sheath meningiomas have in general been disastrous. An excellent paper recently reviewed the experience of Wright et .'11. 15 This was d rE'view of 27 patients with optic nerve she<lth primdry meningiomas, 21 of whom were women. The last two pilTagraphs of that paper are so pertinent that they are quoted here. "Surgery in the patients reported in this paper has been di­rected towards tot<ll removal of the meningioma once useful vision had gone; biopsy and de­compression of the optic nE'rve where vision re­mained; or, if there was d small anteriorly located tumour, its totdl removdl with preservation of vi­sion. A dilemma arises in judging whether to ex­plore the affected optic nerve once the provisional didgnosis h<ls been mdde. If the eye is blind, re­movdl of dll the meningiomdtous tissue prevents growth of the tumour within the orbit or along the optic canal to the chiasm and should improve an dlre<ldy favourable prognosis. If USE'ful vision re­mains, incising the dura should relieve the pressurE' of the tumor on the optic nerve. The results of this procedure havE', however, been disappointing. In illi p<ltients the visual deterioration continued and useful vision WJS destroyed within 18 months, 50 that dnother ldteral orbitotomy was required to excise the meningiom<l.·' Wright"; concluded: "We now believe that the most Jppropri<lte management for p<ltients with relatively good vision is to wait for vision to dete­rior.\ te and then excise the optic nerve together with the meningiom<l. Biopsy or <lny surgery which tr<lnsgresses the durJ should be <lvoided. There are two exceptions. First. if the r<lte of growth of the optic nervI' tumour suggests a malignant type of meningioma, the tumour should be biopsied. Sec­ondly. if high resolution CT sC<lns show a small, very Jnterior tumour dnd useful vision remains, the nerve should be explored, for this type of lesion (,In be T!;"'moved without destruction of vision as in patient two. The results of this type of treatment we Jdvoc.lte C,ln be judged only with d follow-up of v('ry many years." I think it should be pointE'd out th<lt patient two In Wright's seri('s'~' had only light perception vi­sion, h~lw('vE'r. Only nine of 27 patients in his series had optociliary shunts {one-third of the (.151'5), .md our experience has been that this is a I,lte sign in development. At the moment, most neuro~ophthalmologists hJve been following Wright's'5 suggestion that pdtient with optic nerve shedth meningiomas sim­ple be followed until vision deteriorates. However, Journal of Clinical Neuro~ophthalmology we fed tholt the results of r.ldiothN.lpy ,IS .1 nW,II1S of ViSUoll p.llli.1tion in \lptk nerve sh",lth llIenill­giomols holve been ellnlur,l~in~ tll d,lh' Altlwu~h we holve Ilot been .lble hl d,lC1l1l1('nt dl'Cn·.lsl· in size of these tunlllrs by l'lltllpUled tornl'~r.1phy olfter rJ.diother,lpy, \,hjl·\·tivl' dOdlllwllt,ltilln l,f regression .1Ild dis.lppl',lr,1n\·I· l,f l'pll'I'ili,Hy vl'ins holS been ShOWll folll,win~ irr.h:li.lli\'ll, WI' dl' Ilut J.dvocolte r.1di.ltillll thl'r.lpv I\'r every (.lSt· llf men­ingiom. 1tous invllivemellt "f thl' l'plil' lH'rve, hlwv, ever. .1nd differenti,Hil'll llf thl1"1' \"1"\''' Whll ,He surgic.ll c.mdid,lle.. requirt'" (',.ldin~ in\tividu,ll neuw-(>phth.1Inllll\'~k,111.1 nl'urllr,IJi\,I'I~ic .1....1' .... ­ment, Whl'n \lptic nt'I"\'e shl'.lth nH'llin~ill111.1" h.wl' been surgic.1l1y r(1111)\'ed, thl' lIsu,11 result h.l., bl'l'n pwmpt hltJ.1 blindness 'If Ihl' \'YI'. Th(' n,1Iur,11 (llUrSe of the dise.1se l('.lds tIl ,111 im'''lr,lblv Pfll­gressive loss of vision. Alth'lll~h r.ldi\lther,lpy m.1y only help pJ.llidte the p.ltient's visi\ln f\lr pt'rh.1ps .:! yeJrs or Sll. this fllrm \If tr('.1tment definitely WdrrJ.nt", further consider,Hilln. There Me sever.ll questions th.lt r('m.1in hl be dnswered. There .1ppNrs tol->(' .1 tend('llcy for llptic nel"\'e she.1th meningiom.1S to be bil.lter.1[ in some piltients.'h The pl.1ce of thin needle biopsy or open surgicdl biopsy of Ihese lesions dnd the StdtuS of decompression of the optic nerve she.Hh <md/or optic canal remdins to be finally dnswered, The optimum total dose of rddiotherdpy for these tu­mors also must be established precisely. A sm.1lIer total dose-in the r,lllge of 4000 r.1ds-is now being considered for these tumors, since there is some evidence of response of optic nerve menin. giomas to radidtion therapy. At what visual level should radiation therapy bc instituted? One of us OLS) feels that in the presence of an absolutely firm clinical diagnosis (including progressive vision loss with acuity down to 20/80-20/200 level, optic atrophy. optociliary veins, appropriate neuroradi­ologic and computed tomogr.-.phic findings). d coursE' of radiation therapy c<ln be given without biopsy or surgic.~1 intervention in selected cases. The importancE' of an cxpert therdpeutic r.-.diologist who is expE'riE'nced in the rddiother.lpy of optic nerve and chidsm lesions Cdnnot be overemphil­sized. References I. Dandy, W. E.: rre-chiasm.ll lumor~ "f Ill(' \'pli( nerves. Am, /. Oph/h,dmo/. 5: Ib9-Hl;I\, 1922. June 1981 ~ Cr.,ig, W,M.. "nd C"l-:t'l.l, Ll . Mt'Il,ngiom,' "f Ihe "pllt ("r,'I11I'11 .,~ .• , ,llJ~" ", ~I"wly pr"grp~~,vt' blind_ lll'~~. I. Neu"Nlr~. 7: ·[,1-41\. I<JSO. J. W"I~h. r ,IL l. Ml'nll1gi"rn.l~, prim.lry wilhin Ih(' "rhil ,lIId "p'i, ,.m.ll. II. Intr,l<f,mi,ll m('ninKi<lm~~: "'I,I"llt'd l,'~"~ With Il<'Un,·,'phtn.• lmol"K'( inler('~l In Neur, '·"I.hth.,'m"I,,~ySymf" "HIm "f thp Un;".,,· ~itv ot Mi,lI11; ,lI1J th,' H.r~("'l1 1'"I",.'r [v.. /n~I;lulr, V,;" 5, II.. "'milh, [d Huffm,.n f'ubh~hinK C"m­p. l11y, H.lll.lIHl.lil', n,l., 1<J70, PI" 240-302. 4, Su~.ll", I.t 1., ~nlllh, I.L..1I1d W.. I~h. FB. Thr imp()~_ ~ibl,' ,m'nill!"om.L A,,·h. N,'ur"I. 34: 30-31\, 1977. :. H"II,,"h'H~f', feW., Ir., H"II(,llh"f~I, r~.w .. Sr" ,llld M,11C.Hly, c .....: V,~u ..1 pr"Kr",~j~ "f "pt" nl'Tvf' ~h",llh nll'nin!""m,l~ pr"dul inK ~hunt v('~~('I~ un Ih(' "ptll di,.,,: TI1f' Hoyl·... p'·Il\rr ~ynd[(lm('. Tr..n~. Am ()phth,llm"l. -SOl' 75: [41-103, 1°77. t> W('i~l)(',):, LA.. .lnd '.l(llb~, LD.. Orb'l.l1 COmpult>d lomll):r,.phy-An llvt>TVlew, I. C'lIltin. Ed, Oph/h",­nwl. 40: 13-21\, 1078. 7, Smith. [L' Symposium on N('uro·ophth..lm"lo)!:y, Neuro-ophlh"lmolo~y upddte. Ophthdlmo/nxy 86: 303-307, 1070. 8 Knixht, Ct.. Hoyl, W.f.... nd Wil~on, e.B· Syn­drom(' of incipi.'nl pr('chiasmaI oplic neTVe compr('s­sion- Pw)!:ress low.lrd t>~r1y dl~Knosis "nd surgical m"ndgemenl, Arch. Oph/h.llmol. 87: I-I [,1072. 0, Wri)!:ht, I,E.: I'rim,lry optic nerv(' m('nin)!:iomas: elm­ic.. 1 pr('Sl.'n'"lion "nd m,mag('ment. Tr,IllS. Am. Ac"d. Oph/h.,lmol. O/lll"rynX(ll, 83: 017-0'::5, 1977. 10, Wilson, W,B., Gordon, M" "nd lehm.. n, A.W.. Ml.'ningiom..s confined tll thl.' oplic can~l ,.nd fllr~m­in... 5urx- N('ur"I. 12, 2[-28, [°70, II M.. rk, LL. K('nn('rdell, 15.. M.lrnlln, J.e.. ('I .11., Microsul):ic.ll remnv..1 l,f J prim.,'), mlr.ll1rbil,l! meningiom.,. Am. I. Ophrh,llnwl. 86: 704-700,1078. 12, Merritt, H.H., A Tf'\rb,'ol. ,,( Neur"h,i'" (oth "dl. Lt'" & F('biger, I'hil.1delphiJ. [07<>. p. ~44. 13, W"r". W.M., Shelint'. GL. N('\\'m,1I1, H" "I .11., R"di"tion th('fJpy "f menin)!:i\)m~s. Am. I. Rl'f'nt. Kenol. R"d. Th('r. Nud. Med. 123: 453-458, \<>75 14, Fukui. M" Kil"mur", K" Ohg,1n1i. S. et .11.. R.ldl_ osensitivily of m('nin~inm••-An.,lvsls "f five l",ISt'S of highly v"scu!~r ml.'nill~wnM Ire:ll('d by pre,'p('r. "Iiv(' irr,ldi"li,'n. Al"t.l Ncur",·hir..\r;: 47-e>(l. 1077. 15. Wri~ht. 1.1: .. Cll!. N,B.. ,l1ld l\.lrI'·"~' S.. Prim.lrv ,'pill" llcTv(' nll'nin~i,'nl.\. Br. I (lr/l/ll.llrJ1<" M, :.:..\. 551\. IO~O. 10. l•• m('~, IU'.. .lnd Smilh. I.L.: Bil,ller.ll npti( nt'''... sh(',,111 meningH'm.ls rrf's,'nllll~ .1.. Ih,' (h'.l~nl.\l ~vn· Jrome.ln Nf'ur"·"l'hth.llrn"I,,}:\' IIp,I,,tc, r L. Sm;th, [d, M.1ssnn Publishing USA, [n.... NI'\\, ) ,'rk 1<.)77 PI'. I77-It'J. W"I,' I"r rCl'rjJ1t~ t", l. l.nvhlll Smilh, M.D., O~20 S,W.l;12nd Courl, Mi.lmi, FI,,,id,l JJI5t>, ..