Journal of Neuro-Ophthalmology, December 1982, Volume 2, Issue 4

Achromatopsia. Clinical diagnosis and treatment.

Six cases of classic achromatopsia are presented. The methods of practical clinical diagnosis are discussed, including paradoxical pupillary constriction in darkness, the easily performed Sloan achromatopsia test, and electrophysiologic studies which are useful in young children. The visual and cosmetic benefits of heavily tinted contact lenses in such patients are stressed.

T. C/in. NellnHlphtll.l/m,'! Z: 21 '1-220, 1<11\2. Achromatopsia Clinical Diagnosis and Treatment PATRICK S. O'CONNOR, M.D. THOMAS l. TREnlCI, COLONEL, U.S.A.F., M.e. DOUGLAS l. IVAN, LT. COLONEL, U.S.A.!', M.e. JOHN V. MUMMA, M.D. DA\'ID E. SHACKLETT, M.n. Abstract Sh. cases of classic achromatopsia are presented. The methods of practical clinical diagnosis are discussed, including paradm.ical pupillary constriction in dark­ness, the easily performed Sloan achromatopsia test, and eleclrophysiologic studies which are useful in young children. The visual and cosmetic benefits of heavily tinted contact lenses in such patients are stressed. Introduction In revieWing the c.]Uses of blindness in 104<.' children, Pierce l found the most comnllln di.1g­noses to be: I) catMact (13"/0 ), 2) optic atrophy (12":'). 3) wngenital nystagmus (10%). and 4) retro­lental fibroplaSia (b%) When studyingC 40 patients In the group diagnosed originallv as congenital nystagmus, he found 33 were c.]Used by a single gene abnormality, with achromatopsia, .1Ibinism, and Leber's congenit.11 amaurosis being the nlllst common disorders Achrom.1topsia (n1d mono­chromatism, total color blilldne"s). .1Il .lUtoS0Il1.11 recessive disorder, has been reported to ollur .1" frequently as 1/100 persons on the Isl.lIld of ru r,' 6/100 in Pingelap (slander", I .1Ild 1/84,000 in I)en­mark," but only 1/300,000" in the United St.1tl'S. We suspect that ItS inCidence in thiS country m.1V be higher than sugge"ted, and report "ix p.;til'nt'" with classic achrom.1topsi.1, .111 of whom were ini­tially misdiagnosed a" congl'nit.11 nvstagmus. Case] An 18-month-old, white male was referred for evaluation of congenital nystagmus .1Ild poor vi- From th" D"partm"nt "I Ophlh"I",,,I,,gv i1'''ll(. IVM. 111"1. University llf TexJ<, Hl'.llth '-,llt'llll' ( (,llt('l, L,.JIl Allllllllll, Il·'.I .... ; Ophthalm"lugy Br.Bllh (TIT. Dill. U.'-,A.I ",h",,1 "I A"r,,· space Medlune. A,,""p.l<l· M"d""l f),VI''''" (A.I S( .1. Kr,,,'!..' All Force Ba,e, Tex",. December 1982 "ion. I Ie W.1" till' prlldul t llf .1 full·IPrll1, llllrll1al dl'livl'rv pregn.111l v .1Ild W.I" hl'.llthv, eXlept hlr visilln. His Illothl'r noted th.lt he ""ljulnll'd a Illt," espl'ci.lliv in bright sunlight where hiS vIsion .Ip­pl'. Hl'd p.Hticularly pllor He enjoyed plaYing In dimlv lit rl1oms. On ex.llllin.1tllln, the p.ltient held hiS IW.1d dlll\'n with his eves p.lrti.1I1v closed A gro"s pl'ndul.H nyst.1gmus (greater ill the light) W.1S pre"ent. The child .lppe.Hed tll view oblt'cts equally well With either eye but his nvst.lgmus prevented .m .Iccur.ltl' descriptil1n llf his flx.1tion p.1l1erll Verti,.ll OKf\~ were present. The pupil" re.1cted sluggish Iv tll light but nll M.HCUS Cunn pupill.Il'\' .1blwrm.llltv 1\"1~ fllund. Cllnfront.1tilln fields were Illlrm.11 Cnll1­plegic rdr.1ctil1l1 reve.1led .1 +2,75 sphere 111 'b'lth eyes. FundusCl)pic ex.lmll1atil1n W.I~ n,'rm.11 HI~ scotllplC ERC \\',10., nllrm.11 but the ph,'tl'pl( ERe was extinguished, Case 2 An 18-ve.H-old. white fem.lle 1\..10., f,)und ,1n r,'u­tine ex.lmin.IIJ,'n tll h.lve .1 bl'~t ,-,'rrl'ded \'I~I,'n ,,1 20/200 ill bllth eves .1I1d I\"I~ rl'tnred t" 1I~ f,'r l'V.llu.ltll11l1l1 p"l1r VI~I,'Il. She ~t,lted th,lt 1ll'1 \'I~I"11 h.ld .Iltu,lllv impr"\'l'd ~lllle lhildhll"d whell hl'l eVl'" "lumped .1 Illt" .1I1d \\'1ll'1l "bnght Ilghh rl',lllv bllthered me," I!l'r pr"blem 11<11\' 1\'.10., 1\'lth 1ll'.1l­visillll, fl1r IVhid1 she reqlllred re,ldlllg gl.lsSl'S l)n l'x.lInill.1IJlln, her best <,<lnTl ted \'I~I,'n W,I~ 20/200 ill till' nght l'Vl' .1I1d 20 20Ll 111 the Idt l've Ne.n Vi"lllll W.I~ I, ill b,'th l'Vl'~ .1t ~ tll ,) III \\'hl(h Imprllvl'd 1" I, .It 4 I,' 5 III with ,I +350 ,Idd III bl1lh eve". A ~ubtle 11l'lldul.n Ilv~t.lgmlI~ I\',l~ l1<lted III prim.JrV, wllh .1 wrk Ilv~t.lgmu~ m,1I)1Il'~t ,In I.lter.11 g,l/l' Rllulllll' pUI'i1I,H\' te~tlllg .1I)d 11I1ldu~ l'x.lInill.ltl<lll IVl'IT l1<lrm,11 TI1l' Slll.ln .llhrl1matl11'­" i.1 Il'st W.I~ p,'~itivl'. N" ERl, I\',h l'erf,'rnll'd. Case 3 A 14-ye.H-old, white m,11e previ')L1sly diagnllsed .10., h.lVing ll1l1gellit.11 llyst.1gmLls IV.1S seen for a 219 nlutine eve ex.lmin.ltiun. He st.lll'd th.lt .llthuugh the jumping uf his eyes h.ld imprl)Ved, he W.IS still sensitive tu bright lights whidl wlHSl'ned his vision. L,\.lmin.ltiun reve.lll'd .1 best cllrredcd vision of 20/200 in the right l've .lnd 20/200 in the left eye. Rllutine pllpill.lry .lnd fundu<, l·x.lfllin.ltions were nUrlll.11. Utlll'r studies indlldl'd .1 positive Slo.ln .Khn1m.ltl1psi.1 test, 11l1rm.11 sClltopic, .1Ild .Ibsent plwh)pic ER<.;. A 12-ve.lr-llld, Llti n Aml'ric.Hl m.lle was fi rst seen bv ·.In llphth.llnwlogist .It age 13 months. A di.lgl1l'~is l)f congenital nyst.lgmus with amblyopia .lnd eSl)twpia W.1S m.lde at th.lt time. After a neg­. Itivc ev.llu.ltilln bv .1 pl'di.ltric neurologist, the p.ltient underwent .1 bimedial recession for esotw­pi. 1. Since th.lt time his best corrected vision has rem.lined at 20/100- in the right eye ilnd 20/400 in the left eye. He was followed yecHly until age 8 when it was .1ppreciated for the first time that he h.ld .1 significant photophobia and preferred to pl.ly outside only at dusk. Motility testing revealed 15 diopters of residual esotropia and a dissociated vertical divergence. His refractive error at this time was (right eye) -4.25 +3.50 cy!., axis 85, and (left eye) -4.00 +3.50 cyl., .1xis 95. A slight head turn to the right was also noted. A marked pendular nystagmus was present. Routine pupillary and fundus examinations were normal. Confrontation fields were full. He was able to identify several of the pseudoisochromatic Ishi­hara color plates, but Sloan's achromatopsia test was positive. Case 5 A I4-year-old, white male honor student W.1S first seen by an ophthalmologist at age 14 months for photophobia, nystagmus, and poor vision. A diilgnosis of congenitill nystagmus was made and the patient's mother assured that this was not hereditary. As the child grew, she noted improve­ment in the nystagmus but significant trouble with colors (i.e., he would see the color red .1S either red or black) and photophobi.l. At .lge 10, the p.ltient WilS seen for .1 rl)utine ex.lmin.1til)n .1I1d his trouble with color vision .1I1d photl)phl)bi.l noted. Further evalu.ltion reve.lled .1 nl)rm.ll SCl)tl)pic .1I1d e'\tin­guished photupic ERe .Ind pl)sitive SIl).lIl .lchrl)­matopsi. l test. He W.1S refl'rrl'd tl) us .It .lge II for ev.lluatilln llf his severe photophobia (in spite of we.Hing a b.lseb.lll C.lp .1I1d NOIR gl.lsses), .1I1d .1 cosmetic-lily notice.lble exotropi.l. Ex.lmin.ltion reve.lled .1 refr.Ktive error of on +0.75 sphere, OS + 1.25 sphere, with .1 best wr­relted vi "ion of 20/100- in the right eye .1I1d 20/ 200 in the left eye Ne.lr visilln W.1S 20/40 .It bin. lin the right .1Ild 20/40 .It 5 in. llil the left. He h.ld .1 35-dillpll'r .1Itl'rIl.1ting eXl1trupi.l. A subtle pen-dular nystilgmus in the primary position gave way to a jerk nystagmus in extremes of gaze. Marked photophobia was present and routine pupillary testing revealed a sluggish reaction to light, but no Marcus Gunn pupillary phenomenon. A paradox­iC. l1 pupillary constriction in darkness was ob­" erved. Fundus and confrontation field examllla­tions we're' norma!. Figures 6, 57, and 15 of the Dvorine Pseudoisochromatic color plates were eas­ily identified by the patient. A Sloan's achrom~­topSi, l test was positive and a typical achromatIC axis WilS found on the 0-15 (Fig. 1A ). A 40 central scotoma with some generalized constriction was found in both eyes on the Goldmann perimeter (Fig. 2). After a bilateral-lateral rectus recession, the patient was fitted with grade 3 gray-tinted, hard contact lenses (24% transmission) which greatly improved his photophobia. These are worn constantly with sunglasses added for outdoor wear. Case 6 A II-vear-old, white male (brother of case 5) has had nystagmus, photophobia, and poor vision since birth. The patient's mother also noted a decrease in nystagmus with age and trouble with color vision. Previous evaluation had documented an absent photopic ERG, normal scotopic ERG. and a positive Sloan's achromatopsia test. The patient was referred to us along with his brother for eval­uation of extreme photophobia. On examination. refraction was +4.75 sphere in the right eye. and +4.25 sphere in the left eye. Best corrected vision was 20/300 on the right and 20/ 300 on the left. Near vision was 20/50 in both eyes at 4 in. A constant pendular nvstagmus was present in primary, converting to a jerk nystagmus in eccentric gaze. Routine pupillary and fundus ex­aminations were normal. Confrontation fields were full. Careful testing of the pupils demonstrated paradoxical constriction in darkness. Several num­bers on the dvorine pseudoisochromatic plates were correctlv identified, but the 0-15 panel re­vealed .1 tvpiC.ll achromatic axis (Fig. 1 B). Sloan's .lChromatopsi.1 test W.lS positive. The patient was fitted with gr.1de 3 gray-tinted contact lenses to be w~)rn at ,111 times \-vith sunglasses added for outdoor daytime wear. Discussion Although .lchrom.ltopsi.1 may be statistically un­Cl) I1lIlWIl in the gener.ll population, it is a common C.luse of blindm'ss in children diagnosed as con­gellit. 1I Ilvst.lgmus. With rare exception these chil­dren .He otherwise healthy and have a normal or .lblwe-aver.lge intelligence.~This, in addition to its .lUtosom,ll recessive inheritance and symptomatic response to tinted contact lenses, make accurate di.lgnosis essential. Journal of Clinical Neuro-ophthalmology C)'Connor, et ill. 12 11 8 Figures ),-\ .1I1d B. (A) LlrIl'\V,'rth I)-IS 1'.111<'1 f"'Ill c."" S. dl'nwn'lrJllng the tvr".,I,,,,, for .1lhronl.lh fJlhng br'tw('l'tl the dt:'ul.Hl .:Ind triLlIl .l'""~. (B) f.HlhWllrth D-15 t('~1 frorn t..)~l· (1, .1)!..,in rt·v('.llln~ the tyrll.11 .n,I'" f.lr .h.-hrl.)m.lts. LEFT RIGHT Figure 2. GoldmJI1 visUJI ficlds frum (J"'(' 5, deI1H1n ... tr.lting bd,ltl'r.1J It.'IlI!",ll .... llltllll1.1 ....111...1 mild hClWr.t111t'd llllhtl"lltlllil tll .111 lSopt..". Nystagmus, photophobia, ..md poor vision in .111 infant with a normal fundus examination is .llmost pathomneumonic. Important in the differenti.ll di­agnosis at this age are ocular albinism (which C.1I1 be diagnosed by a careful ocul.H examination) .lnd Leber's congenital amaurosis which early on C.ln only be identified by an extinguished or markedly reduced photopic and scotopic ERe. Other nonll­cular neurologic problems are more commlHl in these children as well." With cooperative older children and adults, .1 diagnosis of congenital rod monochromatism can December 1982 usu.llly be m.lde withllut ERe te"ting bv t'"t.1bli"h­ing the prl'Sl'nCl' lIt .1chrllm.ll,'p~l.l. n,ll"m.11"1" ne.n mlrrn.11 pniplll'r.lI vi"lI.t1 fields. IWl"m.ll night \'1­sion, .1I1d .1 ViSu.ll .lcuitv .lI'l'Ulld 20/200. This di­. lgnosis, IHIWl'Vl'l". is fl"l'qul'ntlv missed bl'l".ll1Sl' "'t f.Jilure' tl' inljui I"l' .1bl'Ut the st.ltus l)f nlll'l" vi"il>I1. Additil'n.ll findings th.lt .1I"e' helpful in di.lglll)"is .He': I) photophobi.l .1I1d nvst.1gmu" eitlwl" nl)\\' or in the p.1St, 2) high incidence l)f strl)ng rcfr.1ctive errors, J) muscle imb.ll.lIltT (Cl)J11ml>n), 4) fundus showing no or l)nly minim.11 m.lCul.H chdngE's, 5) nonprogre'ssive course, (,) extinguished photopic 221 Ach ro III ,l tl 'psi,l ERe, 7) norm,ll scotopic ERC, 8) normal or accel­l'r, ltl'd d,Hk ,1d,lpt,ltion, ,1Ild LJ) ,1lItosom,11 recessive inlll'rit,lIll'l' p,lttl'rn. Impllrt,lIlt in the diffl'rl'nti,ll di,lgnosis ,1t this ,1ge ,liT: complete ,Khrom,ltopsi'l without ,1I11blyopi,1, innllll pletl' ,Kh rom,ltopsi,l, progressive cone de­gl'nl'r, ltions, ,1Ild gl'lll'r,llized conl'-rod deficiencies where ,1 nllll' dysfunction predomin,ltl's.!1 The p,ltil'nt ~ith complete color blindness with­out ,1I11bIYllpi,1 (lone mlllllKhrom,ltism) is l',lsily distinguished by norm,ll vision, no nyst,lgmus or phlltllphobi,l, ,1Ild normal or minimal ERC changes. The nlngl'nit,ll incomplete achromat with subnor­m, ll visual acuity h,lS vision ranging from 20/50 to 20/200 with sO~le retention of color vision. Pho­tophllbi, l, nyst,lgmus, and macular lesions are min­im, ll or absent. These p,ltients may perform poorly nn cnlnr testing plates but are often accurate in identifying colors correctly." When alterations in the m,lCular region are present in acquired cone dystrophies on fundus examination, the partial color vision deficit is frequently attributed to 10­c, llized macular disease. Where the macula cannot be im plicated, optic nerve pathology is often sus­pected. Patients with optic atrophy may exhibit a partial loss of color vision and in milder forms vision may be 20/200 or better, with little or no change in the appearance of the optic nerve. III Here the ERG is invaluable, demonstrating an absent photopic response in the acquired cone dysfunc­tion but a normal pattern in localized macular or optic nerve disease. 11 Most important in the differential diagnosis at this age is that rare group of generalized cone-rod deficiencies where symptoms of cone dysfunction predominate and where the fundus may be normal or show only minimal macular changes.!1 Similar findings have been reported in patients with Frie­dreich's ataxia.'~ These patients usually h,lve a history of progressive visual failure, with vision below 20/200, constricted visual fields, and an absent or markedly reduced scntopic ERG. The majority make no mention of difficulty ,1t night and clearly prefer dim illumination ,1lld d.Hkness to vision in daylight." It is import,lllt tll ren'gnize this group because the pwgnnsis here is pOllr compared to the classic ,1chrom,1t. One important difference between cllllgenit,ll and ,1cquired deficiencies in colllr perceptinn is the subject's use of ellior n,lIlWs. The p,ltient will) h,ls once possessed nllrm,ll color visillll but h,ls lost it will see no difference in gr,lYs ,1l1d in chrllm,ltic colors ,1l1d will c,ll1 them ,111 gr,lY. Cnnversl'ly, the congenit,ll achrom,lt will ,1pply different 'colllr n,lml'S to ,1 series of gr,lVs, c,llling d.lfk gr,lVs red, medium gr,lys blue or green, ,1Ild light gr,lys yel­low Red ,1Ild yellow ,1n' llften n,lI11ed correctly bl'C,lUSl' thl' ,Khrom,ll h,ls Il'.lfned th,lt colllrs whicil ,1ppl·.lf light ,Hl' prob,lblY yelillw, tllllsl' which ,1p­[ W,lr d,lrk ,He prob'lblv rl'd" (when shown ,1 red top bottle, for instance, the achromat will say it is either black or red). Achromats have no Purkinje shift and are always functioning under scotopic conditions. I I They also have no hue discrimination and can only judge on the basis of brightness comparison, which helps explain the results obtained on various color vision tests. Contrary to what might be imagined, achro­mats are able to identify a variable number of plates on both the HRR and Ishihara Pseudoiso­chromatic color tests (i.e., cases 4, 5, 6).1" In addi­tion, they may have a characteristic scotopic axis on the Farnsworth 0-15 test ll falling between the deutan and tritan axes, as demonstrated in Figures I A and B, from cases 5 and 6. The Sloan achromatopsia test"; is the simplest and most accurate screening device for the typical achromat with complete loss of hue discrimination and a scotopic luminosity function. The primary purpose of this test is to determine whether a person suspected of total color blindness can, in fact. match all possible colors to some particular shade of gray The test uses standard Munsell colors of high chroma (saturation) covering the entire gamut of hues-i.e., red, yellow-red, yellow, green, purple, and blue-purple. The test provides comparison of each color with a graded series of 17 grays, varying in half-unit steps of Munsell value from 9 (almost white) to 1 (almost black). The color to be matched is presented in a circular aperture in the center of each of the 17 strips composing the gray scale. The subject is first shown a gray scale in which each of the circular apertures contains a gray of value -to The examiner points out that at the upper end of the value scale the circular spots are lighter than the strips. The subject is required to find the position on the value scale at which the relationship changes from "spot darker" to "spot lighter" and thus to locate the pl.1ce where there is a perfect match between strip ,1lld spot. All subjects, both normal and color blind, if thev understand the test, find a perfect match between the gr,l\' strip of value -t and the gray spot llf value -t (Fig. 3). The subject is next shown the gr,l\' selle in which e,lCh circular aperture contains ,1 red l,f v,11ue 5, chromia 12. Nothing is said by the e',lminer to indic,lte this match will differ in any respect frllm the preceding one. The achromat will ,1g,lin h,lVe nl' difficultv in finding a perfect match unless this happens to fall between two steps on the v,llue sc,lle. If he says, for example, that at a v,llue selle of -t the spot is darker than the strip ,1lld ,1t ,1 v,llue level of 3.5 it is lighter, the match is ,1ssumed to be midway between; i.e., at 3.75. The nOflll,ll subject recognizes at once that there can be nn perfect match because of the obvious qualitative difference between the red spots and the gray strips. He can, however, locate a region on the scale where the spot is neither darker or lighter than the strip. Because of the disturbing color difference, it Journal of Clinical Neuro-ophthalmo!ogy O'Connor, et ,II. " I- I· I . h~url' J ....... J, ',Ill .1\ h I ~ '1ll.II. '1''''1.1 k .... j I,I.H,· I dl·J1l\ll\ .... II.lllll~~ I h.11 hili h 1111' 1l.lrlll." Ill.. I ~ .11 r\O\\:) .1111..1 .1' 111\ '1[1.11 1I1;":,ht .lff\\wl \\:111 lll.lJ...e .111 .dc.'lllh:.ll Ill.lh h \\f Ihe ~r,lY ...tnp ... ,Inti c.lfe. L1br ,1rerturl' Lont.lining .1 gr.lV n( v.llue 4 \vhen the llld~ml'nt I.... l,.l~l'd "l)1clv i..'11 bnghtIH·... ~ Cllmp.HI"'PI1 Wlthllul reg.HJ tll hup. -..·1 'N Iv, 10 SL 1-, I~ 'rnr's IA n's 1- Figure..J.. L)!ll.lll .1l11l"llill •.JtUV.,I.l k .... l pl.ltl' 2, Jl·JJll1l1~,lr.ltJllh th.11 \Vhl'l\ llw liJLUl.ll dpl'rlull' llillt.llll~.1 r....d llt lIH\'1111.1 5. the dl..hn1mdt (light ,Hrl1w) <..111 .... till m.lhh thi,:,> III the gr.1V ~trip l)1l the b.hi .... \Jf brightlll·S ..... r'h\\\'l'\'l'r tll1'lh1rm.ll (d.Hk Jrnl\V1 c.JIl flllJ 11(1 rc:rfC'd Ill,ltc.h bl'l.lU"'(' l,f thl' llbvlPU" lju.llit.ltivl' dIHl'fl'lll:l' l1l't\\'l'l'Tl the rl'd SP\,lt ,llhi thl' ~rJY o:.,lflp"', Jnd will 11l.1kt, .111 t'rrtlllt'pu", judh lllt'llt. is more difficult for the normal to m,lke ,I bright­ness match th.ln it is for the .Ichrom,lt (Fig. 4). The same procedure is repeated for each of the rem,lin­ing colors. If the subject can match each ((ll\lr to one of the grays or judges that h(' would m,ltch ,I gray intermediate between two successive Jll(,Jll­bers of the scale, it m,ly be' concluded th,lt ,111 ((ll\lrS are seen as grays that differ from \11ll' ,1l1Other \lnly in lightness or darkness with hue di"niJllill,lti\1I1 December 1982 ((1I11pletely I,Kking. '" The test is givell in st,md,Hd J'lylight illuJllill,lti\1I1 fr\llll ,1 M,lcbeth d.1Vlight 1,IJllp. It is p\lssiblc t\l predict the ,lVer,lge brightness Jllatches \If the n\lrlll,11 ,1I1d th\)se \If the .lVerage .Khroll1,lt (Fig. 5). If the illuJllin,lti\)n is dill1ll1~d until 110 ((ll\lr is seell, the ll\lrJll,11 eve 1l1,ltches will ,lgre(' closely t\l th\lse \If the ,l\:hw';l.lt under ordi­n. lrY levels \If illull1in,lti\ln (Fig. 5). ,,; Although pupill,Hv ,lbIlOrll1.1Iities v.lrying from 223 rvl,l!t Ill" III M'IlIJl'th I ),Ivllght IlllJrlllll.lli~ln -------- 1''',1 5 1111 11"'->1 11\1111 l.l.IV h:nl ) .-II, 'IV (l'll 't,·lll1w ( In'f'n ~\l\lll.d Ill.ll, h '1IlII11.ll \' ·1 (l 'll) I, (I ,~ L1 ·l q '" 1111111111\.1111 1 11 ~,lllll,d Ill.llll1 111\\' ,II" ·11) \ I ,<I ; ,I '" 111111.111111\ :\ \Tl,'~~l' 111.11, h "I I,' ,1\ hIll ·111 1, S ,I ,~ () 0 :;l' m,ll" '" 11l1111l,11\, dlllllil 11.Ilhlli ['urrle-bll.... 17 ~ 7 7 GR EY 100 u 90 z '" 80 ~ ~''z"" 6700 • • V> 50 =0 Cz> 40 • ::E 30 =0 20 u "'- 10 C> • ~ , C> Z "'- 01 02 03 04 THICKNESS mm Figure b. Cr~lph dCtlh1nSlrJtlf1g thJt the lUlllllll)U~ tr~ln"nllttJnlf' \,)f VJrylTlg gr.ldcs of hr~ly-tlntf'd ll'lbC'.... h dependent UPl)!1 the v."lrying thH.. k.JH· ... ~C .... l.f ~ul'h Ir·n ...('.... tllnic diLlt.Jtion llf the pupil lln tr,lIlsfer frl~1ll ,1 d.Jrkened to .! lightened rll() In ~ tll pl~,'r re,lctil'n t,) direct lightl~ h,lve been rep'lrted in the P,l~t, it W.1~ not until recently'" th.lt p.H'ldo'\lcal pupill,l[\' Cl)n­strictil~ n in d.Jrkness \\',lS described in the~e p.l­tients This phelll)menlll1 1V,1S founcl ,1nd rec,)rded by infr.Jred pupill')llletrv in l~ur C,l~e" ;> ,1I1d ('. bl~th "f whl)11l were 11 ye.HS llid l)r 1)lder .1t the tinl\'. Thi" bncling h.1S "l~l) been 11b"cl\·cd In Cl)n~l'n­it. 11 st,ltion.HY night blindncss .lI1d Lebn·~ c,'n~cn­it, ll ,111l,lllrO"i" whi, h .lIT ,11",) di"llrdl'r" In\'ll"'in~ the rdin.l. It h.1" Illlt been llb"en'ed In p,ltll'nh with l(lrtll,ll bllndlll''''' .1nd Ih pn'"enle ~u~~e"h ,1 rl'ti­n. ll r"tlwr th.lIl l ortil ,11 l.lll"l' tllr till' ,ll'LTc.1"e ill V'''Hlll. TIll' l)h"Il"nH'llIlll I" l',I"ilv llb"l'rved bv h.l\'ill~ Ihl' p.ltll'llt ti,\.It\' ,I eli"I.1I1t "bil'lt with the r,ll)m li~hh "". 1\ pl'lllight llr "ther It~ht "llurte l,m be dir," tl'd Fr.lI11 bel,,1V t" ll·l"lte .1 dilll, dlttll~e illu­" llrl,ltll'" III thl' pupil" fhl' rll"lll Ilghh .lre tlh'll 1"tillgui"lwel ,Inel till' 1"If'il" llb",'r\'l'd tIl 11ll1"trid f"r I . .' "", U11e1", tllllU\\'l,eI bv ,1 tll11ll rc,hl.lt,ltill11. IIY1111 I't ,i1 '"·1''1'1 thl" II'.1l 11"11 I'r"b,lblv ,il""ppe.n~ With "h" ,111L! h.l\... IlIlt l1\lll'd It f'.l"t .l~l' 10. ~Vhilc il IILIV I... IIIII' th,11 Ihl" l' h"I1\'l1lL'I1\)1l dl".lppl·,n" IVlth tlllle, b"th uur cases 5 and t> at ages l-l and II still h.Jd ,In edsilv delllonstrated parddoxicdl re- "pl,n~e. . SYlllptulllJtlcallv, the greatest problem tor these p.ltients I~ their IllMked photophobia which results nl,t frl'lll p,lin but frl'lll the degradation l~t vision l.llJ"ecl bv light '" III thl' pa"t thl' ha" been treated With 1\UI[\ "ungLl"~es ,1ncl ,1 b.1seball l'r other brimlllecl Clp tll "h.lde llut Itght tWill ,lblwe. This CllmbillJtit1n \\'.lS lllliv lllllcler.lteiv successful for sever.!1 re,15l~nS II th~se r,ltients ~ontinue to have m.Hkecl phL,tl)ph,)bi,l incllll~rs; 2) str.l\' light Cdn still enter the gl.lSSb fwm .1bLl\·e .Jnd bek"w; and 3) I1lLlSt illlpl~rt.lI1t, thiS (l)mbIllJti,~n 15 unacceptJble c,'smetlcallv ,1I1d results III lll.Jnv IIlstances III the child belllg tauntecl bv hiS (1.J;slllates The best st)lutil~n w~ h.l\'e ft'und· is the (,)mbinatlOn of grade .' gr,lv-tintecl Cl)nt.lct lenses fl)r (onstant we,lr to­~(' ther \\·Ith '-15 sungLlSses f,~r ,'utcloor use. These Ct'nt,Kts pr,)\·ide ,lnly 2-l-2C"':' tr,lnsmissil'n "f ,lm­bient light cakul.ltcd frt~1ll st.lIld.Hcl cun'es devel­llped by l)lll' ,)f us (T.IT.I gl\'Cn the thickness dnd type l)f tint usccl III the lenses (Fig. 0) .-\ recent repllrt'" suggesting that red-tinted ~1.1sses \\Tre prefer.lble In p,ltients with CLlIle dvs­trlll) hle~ led us tl) fit t)llr p,ltient 5 with gr,lcle 3 red­tlllkd lell"es t,l determine if there was in fact dny ,)biecl1n' Y1sll.1lullpr"\'l'ment l'ver gr'lv-tinted len­" 1'". The I',ltient repllrted th,lt his \'isil'n \\',lS better III ,Llvllght cl)ndll1l1ns but the red lenses caused a Ill.nked distll rl1l)n llf his .1bilitv tl~ interpret colors III the l'IWlr,)nmenl. Thev ,1ISl) prl'\'ed tOL~ dark for i11"Ide usc .lncl the p,ltient h,lS returnecl tl~ his grade 3 ~r,l\'-tillkd lenses. This cllmbin.lti')11 llf (l'nt,lct lenses (Fig. 7) and sllllgl.lsses (Fi~ Sj is ct)smetic,lllv .lnd symptomat­Il ·,lllv much sUperil)r tll the l~lcler method of dark ~I.\s~es ,llllill'. Illterl'stillgly, under normal room illllllllll,ltilln these p.ltients can comfortably read with btlth (llllt,KtS ,lnd sunglasses in place 'which (llmbined l~nly .11Il~WS a theoretical transmittance llf 3 tIl -l"~' l,f the incident light' As previllusly mentioned, high refractive errors [ourn,ll of Clinical Neuro-ophthJlmology O'Connor, et .11. Figure 7. C.lse (1 wl'.Hing gf.li..il' J tinted lunt.ld Il'n<.,('<., fpr indllur u....('. ,1re nll're Cl1ll1mcln in the ,Khwmat. With pwper dist-lllce cClrrectiC1l1, hClwever, ,1pproxim,ltely 70°/c, clf the p,ltients under 23 ye,Hs of ,1ge need no further re,lding ,lid. c1 Re,lding distance in these patients, however, is 5 in. or less, effectively elim­mating them fwm C1(cup,ltions for which clear vision between b ,llld 27 in. is essenti,ll, such as acccluntants, bookkeepers, chemists, and machin­ists. The majority of the children reported by Fondac1 were reading regular type in a normal educational setting and none had to resort to read­ing large type or braille. Achromatopsia is reported to occur with a greater frequency in countries such as Denmark" and Israel'-' which have active surveillance pro­grams. In Denmark, for instance, achromatopsia affects a reported 1/84,000 people in the general population. Pearce'sc series would also suggest that in this hemisphere anchromatopsia is more com­mon than previously reported. We were able to collect six cases over a 3-year period, all of whom were misdiagnosed as congenital nystagmus. While only suggestive in nature, these findings warrant an increased awareness of what has hereto­fore been considered a rare disorder. Achromatopsia is an office diagnosis in most older children and adults based on the symp­tom complex of nystagmus and photophobia, whether now or in the past, vision in the 20/100 to 20/300 range, paradoxical pupillary reaction in darkness, full peripheral fields, a scotopic ,1xis on the 0-]5 panel, and a positive Sloan ,Khromatopsi,l test. In the infant with a normal appearing fundus, nystagmus, poor vision, and photophobi'l, an ERe is essential to rule out Leber's congenital am,lU­rosis. Achromatopsia should be considered in ,1ny child diagnosed as congenital nystagmus who ,1lso has photophobia and poor vision bec,lUse symp­tomatic treatment with tinted contact lenses ,1nd appropriate low vision aids will allow them to be productive members of the sighted society. December 1982 Figure 8. C~lS(, l"l wC'.Hing.1 (llmDII1.1til)n llf gr.ldl' J tInted (llnt.ld ]en ...es .1nd sungl.ls~C'S flH d.l\·light l)utdlll1r \\T.H References I. ['e,lrce, W. C.: ClLIses llf bltndne" In children. I04l1 C,lses registered with till' C,lIl,ldl,lIl N,ltllln,lllnstJtutl' fllr the Blind, 1070- 1°73. elll. I l )l'hth'1/ml11 10: 4e10-472, 10 75 .., ['e,Hce, W. C.: Cllngenit,ll nvst,lgmus-CenetJc ,1Ild envirnnment,ll C,lLlses. C,ll1. I 11I'hth,1/111111 13: 1-<) I Q 7S. 3. M,ld,,'n, ['. H .. Tllt,ll ,ll'hrllm,ltllpSl,l In tWll bwthers. Ad,l. l1I'hth,1I111<1/. 015: 51'7-5<13, I Q l17 4. CUT, R. E, MllJ·tlln, N. E, ,lnd Siegl'l, I. M.: Achrn­m, llllpSl,l in I'ingel,lp 1S1,1Ilders. Am. I l1l'hth'1/ml11 72: 7'!o-7Se1, 1Q71 . 5. Nlll'n, M. S.. A<ilnl l11,ltllpsi,l. Frequencv ,1Ild llCCll­p, llilln,ll prllgnllsis. Ad,l. l1I'hth,I/II1<1/' 011:>(3): 553­5Se', IOe'S. el. Hllll11, L, ,1Ild Ll1dberg, C. Y.: A f.J1l1i1y with total color blindne". Ad,l. 11I'hth'1/1l1ll/. 18: 224-258, 1040. 7. Fr,u1l'escl1l'tti, A. I, Fr,uKllis, N., ,1Ild B,lbel, J.: Cho- 225 ,.,,'rdi/),II / fc/"('d"d,'g"/1Cr,llio/)' ('h,lrl,', ( Tholll,l', ~l'llIlgl'l'ld, 111111(11", 1'17,1, 1'1'. L1511_11117 ~. "1111, AI.' /--ri/l'., I /,,/"(,,111.11'1' 1~<'llll"/.l1ld (/)(>roid.II f 'i"",."", \',,'. .c. 11.111"'1' I{,',w, Il.lg,·,.,lowll, M,lry· I.lIlll. 1'177, 1'1', 552-55". Ll. l",\,d'Il,1I1, l" Ril'l'" II.. ,111.1 ~lI'gcl. I, M.: ( o'll' dy,lllIll 1'"11 "Ylld ...,111('". Ar,h. ( )I'hth.llm,'/. 70: 2 J·1­2.\/, IL1"-,, fll "i''\', I'.: 11lf.lIllill' (ll'li, ,llrlll'hy ,v,llI JIIllllII,lIlt Illodl' III Illlll'lIl,lll' ,'. l\cl.l. (ll'hlh,IImo/. (L'III'I'I.) 54: 57, rl)~l). II AUl'rb,llh, U,',lrllrt·lill(lgr.lI'I1Il.11 .IIlJ p"Ylho· I'h\"I<,1I ,Iudl<'" '" ,lthr"m,lh. M"d. /',..,I>/. ()I'h. I/I.llm,,/. 13(0): Il,()-I L15, I ()7,j 12 Klllr'" A., Lilldbl"Ill, U., ,II1d W.IJl'Il"I"Il, L" ({('till,1I dl'g"lll'r.ltillll ill Iwrt'dit,HY ,It.l\i.l. I. N"lIrol ,'\icu,..', 'IIr,>: I\\'< 11I.llr I(): I ~,'-I Ll3, ILlS" 13. ~I".lIl, L. 1..' C"llgl'Il,t.1I .llhrom.ll"I""" A rl'p"rt IIf 1'1,,1'(". I. (ll'lic SO,' Am. 44: 117-12~, 1()54. 14. "rill, A. l.. Krill\ Hcrl'dil.ln' [{dlll,II ,l1lJ Ch"w/J.II pj""",c" Vo/. .c. H.lrper R:,W, H.lger"t,"vll, M.nv· I,llld, I ()77, 1'1', 35()-3"Ll . IS. AUl'rb.Kh, E., .1Ild Merlll, 5,' Achrom.lt"p'lol with .llllb/v"pi." I. A dilli,:.11 .lnd clcdrllrdillt1grolphic.d "tudy of 3() C.1SC'~. 0,.<. Ophth.IIlllll/. 37( I): 7()- J 17, /()74, I", Slooln Achromoltopsiol Test. Munsell Color, Molcbeth Color Division, 2441 North Collvert Stree!. Baltimore, M.Jryl.lIld 21218. 17, Manty;:irvi, M,: C'lngenitoll olchromoltupsia in a Fin­nish folmily. Act.l, Ophth'l/mol. 56: b82-688, 1978, III FIYlln,), T, K.lzMi,lIl, E.. and Bolrricb, M.: PJf.ldox­i, .;1 pupil III congenital olchromatopsiol, Int, Oph­Ih, IImo/. 3(2): q 1-9b, 198 J I() ~IO,lll, (" L, ,lnd F('oick, K,; Acuity-luminance func­11<' 11 III .lLhrumat"p~iol olnd in progrC'ssive cone de­g" IH'r,ltioll: Folctors related to individual differences III tll/c'r,lllCe to bright light. Invesl, OphthalmoJ. 11(10): 802-8t>8, l<ln 20. Yuung, 1< S L, Kr<'fman, R A., olnd Fishmoln, G. A,; VI~uoll 'lllprovemC'nt~ with red tinted glolsses in ol poltient with cune dystrophy Arch Ophtha/mo/, 100(2): 2t>8-271, J()82 21. Fund.l, C, .lnd Thomas, H. Correction of low visual ,lcuitv in olchromoltupsi.l. Cse of corrective lenses olS an ':lId tu educatiunal olnd vocoltionoll placement, Anh. OphthJ/mo/. 91(1): 20-23, 197-l. ~Vrite ("I' reprints to: Poltrick S. O'Connor, M,D" Dppolrtment of Ophthollmology, Cniversity of Texas He.llth Science Center, Soln Anlt>nio, Texas 78284 ",Journal of C1iniColl Neuro-ophthalmology / . "