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The significance of minor defects of visual acuity in school children: Implications for screening and treatment
68
Surv Ophthalmol
32( 1) July-August
1987
CURRENTOPHTHALMOLOGY
this quality will lead to any increased erosion into the sulcus. On the other hand, the lens is an extremely light lens, frequently weighing much less than 1 mm in the aqueous, and therefore is unlikely to have any significant inertial forces from the saccadic and other motion of the eye. For this reason, one would expect a decrease in damage to the sulcus as a result of this characteristic. Time alone will tell which, if any, of these factors is operative and significant. THORI.XS R. MAZXO~:C:O, M.D. \‘..\X Nt1ys, C:\r,ri.X~K~l~\
The Significance of Minor Defects of Visual Acuity in School Children: Implications for Screening and Treatment, by S.L. Stewart-Brown and R. Brewer. Truns Ophthalmol Sot UK 105:287-295, 1986. Considerable effort is expended in seeking and treating visual defects in school children with the belief that such defects may interfere with educational progress and other aspects of child development. One in ten primary school children has been prescribed spectacles by 10 years of age, and 12% have had their vision tested every year. Although the majority of children who have been prescribed spectacles by age 10 have significant visual defects, quite a high proportion have only a minor visual loss caused by uncomplicated refractivre errors. Evidence that the latter could interfere with normal development is insubstantial, and the value of treating these defects has not been tested in randomized control studies. Information collected on the children of the 1970 birth cohort study has been used to examine the educational performance of children who have minor defects of visual acuity. Results suggest that children with mild degrees of hypermetropia may experience difficulty learning to read, but with exclusion of this group, significant educational disability was not associated with minor visual defects. The significance of this finding is placed in the context of the value of current practice in screening and treating visual defects for school children. (Author’s address: Dr. S.L. StewartBrown, Department of Child Health, University of Bristol, England)
Comment Opinions on the value of vision screening in infancy ranges from unqualified enthusiasm (Reinecke RD: Arch Ophthalmol104:33, 1986) to extreme scepticism (Taylor DSI: Trans OphthalmolSoc UK 104:637-640, 1985). The latter opinion is derivred from actual experience while the former is perhaps derived from theoretical principles. Apart from the very few serious defects such as cataracts or retrolental libroplasia, the main thrust of vision screening in children has been to detect refractive errors and amblyopia; the corollary of this is that the early detection of such defects can be corrected and it will benefit the individual and society. It must also follow that the screening itself would have no deleterious effects. The principles and practices of screening for diseases have been laid out by Wilson and Jungener (Wilson JMB, Junger G: Public Health Paper No. 34, Geneva, WHO, 1968) and were cited by Ingram (Ingram RM: Tram Ophthalmol Sot UK 104:646-647, 1985) in a paper which cast considerable doubt on the values of visual screening programs in three-year-old children. Sarah Stewart-Brown from the Department of Child Health in Bristol, United Kingdom, has contributed important information about this whole matter by studying a cohort of children born in one week in 1970. As many as possible were reviewed at ten years of age by questionnaire, interview and medical examination in 1980. 13,782 questionnaires were completed and visual data were obtained on 12,853. Information was also obtained about the children’s reading ability, intelligence levels and socioeconomic classes. This study involved children from all the United Kingdom except Northern Ireland, but regional differences were not very marked. Spectacle wearers comprised approximately 10% of the total group, and among the spectacle wearers 20% had perfect vision without glasses while 10% had a minimal distance defect (20/30). The remaining 70% either had mild or severe distant defects, near defects or mixed defects (Stewart-Brown SL: Br J Ophthafmol 69:874-880, 1985). Only 60% of the children brought their glasses to the visual screening examination and it may be surmised that a large proportion of the 40% who did not bring them did not wear their glasses very often. It is obviously a matter for concern that one-third of the children for whom spectacles had been prescribed had normal or nearly normal vision; however, glasses could have been ordered for many
CURRENT
OPHTHALMOLOGY
69
diKcrent reasons, including headaches and poor school pcrfwmancc. In children hcadachcs arc‘ rawI>, c-auscd by refi-ac.ti\re errors. so many glasses would have hcrn unnecessarily ordered fi)r this symptom. Many optometrists and ophthalmic opticians helir\xx that vrr? minor errors ofrcfraction can aflixct wading ability and that the)- should he corrected: ho\vr\er. there dots not s(w71 to he any scientific proof‘ that sprctacles do make any difbence to school performance apart from the usual placebo A‘t‘ect. E;\idrncc fbr this has heel1 gi\vcw by Hclvestc,n ct al (Hetveston Ei\l. et al: .ANI,/ O~htholmi 09:316-355. I98.5 I as ~~~11as II\. Stewart-Bro\vn (Stcwxrt-Bro\vn SI,, Bre\ver R: Turn Ophthnlnd ~Soc. I .K 10..?:287-29.i. 1986). \xzho sho~vctl that m\-apes. corrected or not, lwrformrd better than a\wug:e on intclli,qcncc and rcadin,q tests. Thcrc was some suggestion that children xvho performed poorly on a near x,ision test scored less wrll in rcadin~ tests. hut thcst mav both 1~ retlvctions of the poor concentration that is shown in children \vho have learnin,q difliculties. Th( nrar \.iaion trst used \vas the Sheridan Gardiner. ivhich has lcttrrs suhtcnditq ti\.e sc~onds ofarc and rtyuircs concentration to l7c read corrc’ctl~.. hlost oi‘th<* children Ii)r \\.hom spectacles had hc~n ortlcred \vould ha\-c hwn rcf‘erreci to ol’hth;tlmolo~ists OI opticians Ix~~ause of‘ poor pvrfbrmancc in a vision scrwning test. Rcftirral is rccr)mmcvldcd if’ the acuity dots not reach the, le\,cl of 20/X1 in each eye. However, many minor tlcfkc,tn ol‘uniocular visual awit)~ arc prohahl! best leti uncorrwtcd as the disadvantages of wearing glasses out\vciP;h the minor ad\xntayes of incrcasrd acuit\.. It is also common li)r children who haIre 20/30 in each cyc to lx able to wad 120/W \\,ith lwth CVC~ nix> ‘II,* to~ethcr. So it seems inccllltrc~\.ertihle that screening has some harnifrtl effects in that spwtaclcs prescri)wd iibr no or minimal visual defects. Thcrc, is atill unccrtaint) about the age at tvhich amhly~pia trcatmcnt is cllCcti\.c. Ingram fbuntl that scrccniyg at 35’~ >‘cars of‘aqv \vas oflittle \.alue, as most of the. children \vith se\w(‘ amhl!.opia \\-erc aIrtad!. under twatmcnt fi)r squint and those who were nc~vly dctcctcd ~hocvcd littlc impro~~cmrnt of \ihion \vith trcatmvnt. Hc l’clt that equal improvements could lw ohtaintld at an older age. Rrliahlc \,isual \c-rwnin~ methods arc not a\.ailahle ti)r children )ounger than 39’2. l’hotorrfraction ma)’ help in dctvctinq large rcf’ractive errors in intanc!, hut modcratc drgrces of astigmatism arc commonI!. ti~und: thew uauall~- disappwr sl,ont~~~lcoulrl\. and thcrc is no cx,idence at this stagr that the\ can c‘auw amhlvopia. Sinw thcrc is ;I \‘(*r\ strong hereditary tc&rnc)in am))l!,opia and squint, children and sil)lings of. pec~,~lc \\.ith strahismrla or am’l~l\~~~l~iC~ should IIt. chcckcd rc,yularl\ _ hut this should tw do~w on an incli\%~ual hasis. .A11o~~l~tt~atmolo~ists arta ~laturally conccrncd about the danger of‘injur!. to thv good e\.cs in aml~l~op~~s. the likelihood of which is rcportcd to he 1.75 per 1000 amt)l!~opcs in Finland (Tommila 1.1 ‘l’arkkancn A: HY,/ O/d~tholrmdGl:.57,5-~j77. 1981 ). It is estimated that 28.i% ol‘aml)lyopvs \vill impro\~t~ spontancousl) aitcr injur! to the ~ootl c\ c ( \ycrcc~ckcn E:P, Brahant P: Al~c-h ~pht/~n/rr~~/ l/b’;220-22-k. 1081): ho\vwvr mail! 01’ the rcmaindcr \vill Ix sc\-crcl\ incapacitated 1,~ their amhlyopia. From the doubts raised it wcm~ that I’urthvr screening programs usins_ vsistin,q guidelines arc unlikcl\- to 1~ 01 an!. great henc’fit and this \\ Irol~~ nlattc*r obviousI\ rcquircs 1w-L careful consideration l&orc o~~l~tl~~~ln~c~logistsrwon~mct~cl that cx)mmrl~litivs tlndvrtake cstc%nsi\,c scwcninq programs. (;l
ICI:1
l’tl.
.\l.lI.
11l:l.l3~ )I RX1 . .\I.\1 I< \I.1 \
Results After P-irradiation ence, by P.K. Lommatzsch.
( *osRu/106Rh) of Choroidal
Melanomas:
20 Years’ Experi-
Br J Ophthnlmol 70~844~8.51. 1986
‘This is a rrtrospccti\r study conducted from 19&l to 1984 on 309 patients with choroidal melanomas treated lvith beta irradiation application. In 216 casrs (70%) this treatment \vas succcssli~l fi)r a mean follwz up period of‘6.7 years after irradiation. In 33 cases ( 17% ) the eye had to he cnucleatcd. and 40 patients ( 13% J I 14 (.5:3’%) dr\x++rd tlat died liom metastascs within this period. Of the 216 succcssft~tl~ treated patients. scars and 49 (23%) retained a \.isual acuity of I .5-0.l. Radiogenic late complications with damage to the retinal capillary system \vcrc the main C~LISCS of~~isual deterioration. especially in eyes with tumors close to the posterior pole. The sur\-i\-al rate is suhstantiall~~ higher than that fbr those patients \vhosc e>.es were primarily enuclcatcd. The author co~lclud~s thercfi)rc that to curt beta ray applicators can hc rccommendcd as an rfl‘rctivc tool and a simple and chc2p proccdtirc
Surv Ophthalmol
32( 1) July-August
1987
CURRENTOPHTHALMOLOGY
this quality will lead to any increased erosion into the sulcus. On the other hand, the lens is an extremely light lens, frequently weighing much less than 1 mm in the aqueous, and therefore is unlikely to have any significant inertial forces from the saccadic and other motion of the eye. For this reason, one would expect a decrease in damage to the sulcus as a result of this characteristic. Time alone will tell which, if any, of these factors is operative and significant. THORI.XS R. MAZXO~:C:O, M.D. \‘..\X Nt1ys, C:\r,ri.X~K~l~\
The Significance of Minor Defects of Visual Acuity in School Children: Implications for Screening and Treatment, by S.L. Stewart-Brown and R. Brewer. Truns Ophthalmol Sot UK 105:287-295, 1986. Considerable effort is expended in seeking and treating visual defects in school children with the belief that such defects may interfere with educational progress and other aspects of child development. One in ten primary school children has been prescribed spectacles by 10 years of age, and 12% have had their vision tested every year. Although the majority of children who have been prescribed spectacles by age 10 have significant visual defects, quite a high proportion have only a minor visual loss caused by uncomplicated refractivre errors. Evidence that the latter could interfere with normal development is insubstantial, and the value of treating these defects has not been tested in randomized control studies. Information collected on the children of the 1970 birth cohort study has been used to examine the educational performance of children who have minor defects of visual acuity. Results suggest that children with mild degrees of hypermetropia may experience difficulty learning to read, but with exclusion of this group, significant educational disability was not associated with minor visual defects. The significance of this finding is placed in the context of the value of current practice in screening and treating visual defects for school children. (Author’s address: Dr. S.L. StewartBrown, Department of Child Health, University of Bristol, England)
Comment Opinions on the value of vision screening in infancy ranges from unqualified enthusiasm (Reinecke RD: Arch Ophthalmol104:33, 1986) to extreme scepticism (Taylor DSI: Trans OphthalmolSoc UK 104:637-640, 1985). The latter opinion is derivred from actual experience while the former is perhaps derived from theoretical principles. Apart from the very few serious defects such as cataracts or retrolental libroplasia, the main thrust of vision screening in children has been to detect refractive errors and amblyopia; the corollary of this is that the early detection of such defects can be corrected and it will benefit the individual and society. It must also follow that the screening itself would have no deleterious effects. The principles and practices of screening for diseases have been laid out by Wilson and Jungener (Wilson JMB, Junger G: Public Health Paper No. 34, Geneva, WHO, 1968) and were cited by Ingram (Ingram RM: Tram Ophthalmol Sot UK 104:646-647, 1985) in a paper which cast considerable doubt on the values of visual screening programs in three-year-old children. Sarah Stewart-Brown from the Department of Child Health in Bristol, United Kingdom, has contributed important information about this whole matter by studying a cohort of children born in one week in 1970. As many as possible were reviewed at ten years of age by questionnaire, interview and medical examination in 1980. 13,782 questionnaires were completed and visual data were obtained on 12,853. Information was also obtained about the children’s reading ability, intelligence levels and socioeconomic classes. This study involved children from all the United Kingdom except Northern Ireland, but regional differences were not very marked. Spectacle wearers comprised approximately 10% of the total group, and among the spectacle wearers 20% had perfect vision without glasses while 10% had a minimal distance defect (20/30). The remaining 70% either had mild or severe distant defects, near defects or mixed defects (Stewart-Brown SL: Br J Ophthafmol 69:874-880, 1985). Only 60% of the children brought their glasses to the visual screening examination and it may be surmised that a large proportion of the 40% who did not bring them did not wear their glasses very often. It is obviously a matter for concern that one-third of the children for whom spectacles had been prescribed had normal or nearly normal vision; however, glasses could have been ordered for many
CURRENT
OPHTHALMOLOGY
69
diKcrent reasons, including headaches and poor school pcrfwmancc. In children hcadachcs arc‘ rawI>, c-auscd by refi-ac.ti\re errors. so many glasses would have hcrn unnecessarily ordered fi)r this symptom. Many optometrists and ophthalmic opticians helir\xx that vrr? minor errors ofrcfraction can aflixct wading ability and that the)- should he corrected: ho\vr\er. there dots not s(w71 to he any scientific proof‘ that sprctacles do make any difbence to school performance apart from the usual placebo A‘t‘ect. E;\idrncc fbr this has heel1 gi\vcw by Hclvestc,n ct al (Hetveston Ei\l. et al: .ANI,/ O~htholmi 09:316-355. I98.5 I as ~~~11as II\. Stewart-Bro\vn (Stcwxrt-Bro\vn SI,, Bre\ver R: Turn Ophthnlnd ~Soc. I .K 10..?:287-29.i. 1986). \xzho sho~vctl that m\-apes. corrected or not, lwrformrd better than a\wug:e on intclli,qcncc and rcadin,q tests. Thcrc was some suggestion that children xvho performed poorly on a near x,ision test scored less wrll in rcadin~ tests. hut thcst mav both 1~ retlvctions of the poor concentration that is shown in children \vho have learnin,q difliculties. Th( nrar \.iaion trst used \vas the Sheridan Gardiner. ivhich has lcttrrs suhtcnditq ti\.e sc~onds ofarc and rtyuircs concentration to l7c read corrc’ctl~.. hlost oi‘th<* children Ii)r \\.hom spectacles had hc~n ortlcred \vould ha\-c hwn rcf‘erreci to ol’hth;tlmolo~ists OI opticians Ix~~ause of‘ poor pvrfbrmancc in a vision scrwning test. Rcftirral is rccr)mmcvldcd if’ the acuity dots not reach the, le\,cl of 20/X1 in each eye. However, many minor tlcfkc,tn ol‘uniocular visual awit)~ arc prohahl! best leti uncorrwtcd as the disadvantages of wearing glasses out\vciP;h the minor ad\xntayes of incrcasrd acuit\.. It is also common li)r children who haIre 20/30 in each cyc to lx able to wad 120/W \\,ith lwth CVC~ nix> ‘II,* to~ethcr. So it seems inccllltrc~\.ertihle that screening has some harnifrtl effects in that spwtaclcs prescri)wd iibr no or minimal visual defects. Thcrc, is atill unccrtaint) about the age at tvhich amhly~pia trcatmcnt is cllCcti\.c. Ingram fbuntl that scrccniyg at 35’~ >‘cars of‘aqv \vas oflittle \.alue, as most of the. children \vith se\w(‘ amhl!.opia \\-erc aIrtad!. under twatmcnt fi)r squint and those who were nc~vly dctcctcd ~hocvcd littlc impro~~cmrnt of \ihion \vith trcatmvnt. Hc l’clt that equal improvements could lw ohtaintld at an older age. Rrliahlc \,isual \c-rwnin~ methods arc not a\.ailahle ti)r children )ounger than 39’2. l’hotorrfraction ma)’ help in dctvctinq large rcf’ractive errors in intanc!, hut modcratc drgrces of astigmatism arc commonI!. ti~und: thew uauall~- disappwr sl,ont~~~lcoulrl\. and thcrc is no cx,idence at this stagr that the\ can c‘auw amhlvopia. Sinw thcrc is ;I \‘(*r\ strong hereditary tc&rnc)in am))l!,opia and squint, children and sil)lings of. pec~,~lc \\.ith strahismrla or am’l~l\~~~l~iC~ should IIt. chcckcd rc,yularl\ _ hut this should tw do~w on an incli\%~ual hasis. .A11o~~l~tt~atmolo~ists arta ~laturally conccrncd about the danger of‘injur!. to thv good e\.cs in aml~l~op~~s. the likelihood of which is rcportcd to he 1.75 per 1000 amt)l!~opcs in Finland (Tommila 1.1 ‘l’arkkancn A: HY,/ O/d~tholrmdGl:.57,5-~j77. 1981 ). It is estimated that 28.i% ol‘aml)lyopvs \vill impro\~t~ spontancousl) aitcr injur! to the ~ootl c\ c ( \ycrcc~ckcn E:P, Brahant P: Al~c-h ~pht/~n/rr~~/ l/b’;220-22-k. 1081): ho\vwvr mail! 01’ the rcmaindcr \vill Ix sc\-crcl\ incapacitated 1,~ their amhlyopia. From the doubts raised it wcm~ that I’urthvr screening programs usins_ vsistin,q guidelines arc unlikcl\- to 1~ 01 an!. great henc’fit and this \\ Irol~~ nlattc*r obviousI\ rcquircs 1w-L careful consideration l&orc o~~l~tl~~~ln~c~logistsrwon~mct~cl that cx)mmrl~litivs tlndvrtake cstc%nsi\,c scwcninq programs. (;l
ICI:1
l’tl.
.\l.lI.
11l:l.l3~ )I RX1 . .\I.\1 I< \I.1 \
Results After P-irradiation ence, by P.K. Lommatzsch.
( *osRu/106Rh) of Choroidal
Melanomas:
20 Years’ Experi-
Br J Ophthnlmol 70~844~8.51. 1986
‘This is a rrtrospccti\r study conducted from 19&l to 1984 on 309 patients with choroidal melanomas treated lvith beta irradiation application. In 216 casrs (70%) this treatment \vas succcssli~l fi)r a mean follwz up period of‘6.7 years after irradiation. In 33 cases ( 17% ) the eye had to he cnucleatcd. and 40 patients ( 13% J I 14 (.5:3’%) dr\x++rd tlat died liom metastascs within this period. Of the 216 succcssft~tl~ treated patients. scars and 49 (23%) retained a \.isual acuity of I .5-0.l. Radiogenic late complications with damage to the retinal capillary system \vcrc the main C~LISCS of~~isual deterioration. especially in eyes with tumors close to the posterior pole. The sur\-i\-al rate is suhstantiall~~ higher than that fbr those patients \vhosc e>.es were primarily enuclcatcd. The author co~lclud~s thercfi)rc that to curt beta ray applicators can hc rccommendcd as an rfl‘rctivc tool and a simple and chc2p proccdtirc