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Visual Development and Refractive Changes in Congenital Cataract
Visual Development and Refractive Changes in Congenital Cataract ELISABETH SCHULZ Abteilung Pleoptik und Orthoptik, University Eye Clinic, Hamburg, FRG
Six to 10 years follow-up data of refractive power and visual acuity in children operated early for bilateral (n = 8) and monolateral (n = 7) cataract are presented. The visual acuity in both groups is subnormal but increases up to school age (retarded development). Reduction of hyperopia is present in both groups with two exceptions in the bilateral aphakic patients. Refractive changes are most proi;tounced in the first one to two years of life and in Down's Syndrome. It ranges up to 14D in monolateral cases and even more in bilateral cases. The time course and amount of refractive change is unpredictable in an individual case. Keywords: Refractive power; Visual acuity; Cataract; Refractive changes dense congenital cataract during the first six (in exceptional cases up to 11) months of age, their When we first started with the optical correction and optical and orthoptic rehabilitation was initiated in orthoptic rehabilitation of children operated (in the this clinic and they had enough clinical follow-up first year of life) for congenital cataract, two data in the same clinic up to school age or even the second decade of life. There were eight bilateral and questions arose. 1. How good is the visual acuity in early operated seven monolateral cataract patients, who fulfilled cases and will it be maintained beyond the age of these conditions. amblyopia risk? 2. Do refractive changes occur, to what extent, at what time course and are they predictable in an RESULTS individual case. The first question has been partly answered by Monolateral cataract Schulz [1], who showed that there is a dependency on the age of operation; this was confirmed by Birch and The visual acuity is not only dependent on the age at Stager [2]. In addition, Schulz [1] stressed that there operation but also on the age of assessment of the is a retarded development of visual acuity up to early visual acuity (Fig. 1). There is an increase of visual school age. Looking at the second question von Noor- acuity up to school age. Visual acuity of0.6 is mainly den and Lewis [3] presented some biometric data on achieved and maintained with two exceptions. One unoperated monolateral congenital cataract, which patient had a late operation at the age of 11 months showed that there is a high axial length myopia in and suffered from secondary glaucoma. A second almost all of them, this was in agreement with other patient, who for the first 5 years responded well to data in experimental amblyopia in animals [4]. orthoptic treatment, after ab~olute non-compliance of patching had a drop of visual acuity to 0.05 (Fig. 1). INTRODUCTION
MATERIALS
The patients of the University eye clinic who were included in this study, underwent early operation for Please address all correspondence to: Dr Elisabeth Schulz, Abt. Pleoptik und Orthoptik, University Augenklinik Hamburg, MartinistraBe 52, D-2000 Hamburg 20, FRG. 0955-3681/90/040253+04 $03.00/0 © 1990 Bailliere Tindall
Bilateral cataracts
There is an age-dependent development, which implies that an increase in visual acuity with age 0.5 to 0.6 can be achieved (Fig. 2). In some cases there is an intraocular difference due to amblyopia, but orthEur J Implant Ref Surg, Vol2, December 1990
E. Schulz
254 Unilateral congenital cataracts 1.6 1.2!1 1.0 0.8 0.63 0.!1 ~
0.4
""
0.32
·;
.
a
·;;"
0.2 0.16 o.l o.o8
.. . ....
..
•••
I
~CI
c •
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o•L..W.
82 op 7 Mo.
• • F. T.
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c.J.
~
oo
0.063
H
op 3 Mo.
82 op 4 Mo. I. D. ~ 80 op 4 Mo.
0.0!1
4
3
8
10
9
II
12
Age (yean)
Fig. 1 Visual acuity in early operated monolateral cataract vs. age. Filled symbols: phakic eye; open symbols: aphakic eye Bilateral congenital cataract a • A.L.. • S.B. 1.0 0.8 0.63
~
" "" 0 >•"
0.32 0.25
•
0.2 0.16
...
~
0.5 0.4
• •
;.
..
*
0.12!1
•i
.
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. •
• M.H. • S.R. •M.D. -lfR.G •
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•
*
.
J
0.1
• B.N.
•
!
0.08 0.06!1 0.0!1 3
4
8
9
10
II
Age ( yearal
Fig. 2 Visual acuity development in early operated bilateral congenital cataract (seven patients). Equivalent symbols for right and left eyes; monocular and binocular visual acuity indicated by filled and open symbols respectively
optic treatment with part time occlusion ofthe better eye can be successful, as shown in Fig. 2 for patients BNandSR. Refractive changes
Assessment of refractive power in congenital cataract is usually performed by retinoscopy. The following data are taken from the clinical report of the patients. Refraction data thus obtained may not be exact in a strictly biometrical sense. This is due to
difficulties, especially in small children with inappropriate fixation in small pupillary opening and/ or secondary cataract and considerable nystagmus. In addition it will make a difference and give rise to some errors whether the refraction is obtained as an additional refraction over a fitted contact lens with high refractive power, over glasses of different vertex distance, and whether it is taken under general anaesthesia, when the visual axis has to be estimated in someway. The data of the group of bilateral cataracts may especially bear some errors. A few examples are illusEur J Implant Ref Surg, Vol2, December 1990
255
Development and Changes in Congenital Cataract Monoloterol congenital cataract
34
o
L.W.
• 1.0. o C.J .
• s.s.
• R.E. v
c
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.!! u
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)I
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u ~ ~
12 I
IO
8
I
I
I
I
4 6 8 10 IZ Months
6
Z
3
4
5
6
7
8
9
10
II
Years
Fig. 3
Refractive power of contact lens correction us. age in seven patients operated on early for monolateral congenital cataract
trated below. A contact lens correction of +30 D will equal a spectacle correction of+ 22 D in 12 mm vertex distance, +20.6D in 15mm and 18.7D in 20mm vertex distance. A +35 D contact lens correction will equal a +24.6D, +23D or +20.6D spectacle correction respectively. So an 8 mm error in vertex distance will make a 3 to 4 D difference for the correction. Monolateral cataract
Refractive power ofthe contact lens correction for the far distance and for the aphakic eye is shown in Fig. 3 for seven patients. All patients show a considerable reduction of hyperopia some to rather myopic ranges of axial length (corneal curvature changed only little). This reduction of refraction may last up to early school age in four cases, two others seem to be rather stable from later pre-school age. The reduction of hyperopia is 7-14D, mean 9D. Two higher amblyopic patients, RE and ID, are less affected than the others. Bilateral cataract
The results of the longitudinal study in refractive power are shown in Fig. 4; one patient, HT, was implanted with an iris-fixated IOL during the first Eur J Implant Ref Surg, Vol2, December 1990
operation at the age of 8 months. This patient as well as JM suffered from Down's Syndrome. The first showed a tremendous reduction of hyperopia during follow-up, the second showed a 10 D reduction of hyperopia from month 11 to month 12 of age. Two patients, MD, who started with a rather low refractive power compared to the others, and IPK, who had been operated elsewhere and came to our clinic at the age of 1 year, had a rather stable refractive power during all the years of follow-up. In the latter, early data were not available. All other patients showed a considerable reduction of hyperopia mainly in the first year of life, except patient BN, whose refractive power decreased up to the age offour. CONCLUSION
It would seem that the initial questions can be answered in the following way. Refractive changes occur in most cases. For each individual case they are generally unpredictable concerning the onset, amount and time course. There may be over 10 D refractive change (e.g. in Down's Syndrome). In our series no data was available before the age of 3 months. The overall impression from our findings was that any kind of refractive surgery, implant or other, should be restricted to those cases in whom contact lens correction fails.
256
E. Schulz
: ~ ~:~: I.P.K
Bilateral congenital cataract
o o
• • A.H.T. M,Down
•
t
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9
10
• • J.M. • • N.Ue. • 0 M.E.
M. Down
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14
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12
•
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0
•
10
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8
•
6
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a:
I I I I I 4 6 81012 Months
4
2
3
4 \5
2
Y:ara 7
8
II
~
Fig. 4 Refractive power of spectacle correction (vertex distance 12 mm) us. age in eight patients operated early for bilateral congenital cataract. Right and left eye: filled and open symbols respectively
REFERENCES 1 E. Schulz. Refractive changes and retarded visual development in aphakic children after operation for congenital cataract. In Detection and Measurement of Visual Impairment in Preverbal Children. Documenta Ophthalmologica Proceedings, Series 45. London, 1985,pp.260-267.
2 E.E. Birch and D.R. Stager. Prevalence of good visual acuity following surgery for congenital cataract. Arch. Ophthalmol., 106, 40-48 (1988). 3 G.K. von Noorden and R.A. Lewis. Ocular axial length in unilateral congenital cataract and blepharoptosis. Invest. Ophthalmol. Vis. Sci., 28,750-752 (1987). . 4 E. Raviola and T.N. Wiesel. An animal model of myopia. N. Engl. J. Med., 312, 1609-1615 (1985).
Eur J Implant Ref Surg, Vol2, December 1990
Six to 10 years follow-up data of refractive power and visual acuity in children operated early for bilateral (n = 8) and monolateral (n = 7) cataract are presented. The visual acuity in both groups is subnormal but increases up to school age (retarded development). Reduction of hyperopia is present in both groups with two exceptions in the bilateral aphakic patients. Refractive changes are most proi;tounced in the first one to two years of life and in Down's Syndrome. It ranges up to 14D in monolateral cases and even more in bilateral cases. The time course and amount of refractive change is unpredictable in an individual case. Keywords: Refractive power; Visual acuity; Cataract; Refractive changes dense congenital cataract during the first six (in exceptional cases up to 11) months of age, their When we first started with the optical correction and optical and orthoptic rehabilitation was initiated in orthoptic rehabilitation of children operated (in the this clinic and they had enough clinical follow-up first year of life) for congenital cataract, two data in the same clinic up to school age or even the second decade of life. There were eight bilateral and questions arose. 1. How good is the visual acuity in early operated seven monolateral cataract patients, who fulfilled cases and will it be maintained beyond the age of these conditions. amblyopia risk? 2. Do refractive changes occur, to what extent, at what time course and are they predictable in an RESULTS individual case. The first question has been partly answered by Monolateral cataract Schulz [1], who showed that there is a dependency on the age of operation; this was confirmed by Birch and The visual acuity is not only dependent on the age at Stager [2]. In addition, Schulz [1] stressed that there operation but also on the age of assessment of the is a retarded development of visual acuity up to early visual acuity (Fig. 1). There is an increase of visual school age. Looking at the second question von Noor- acuity up to school age. Visual acuity of0.6 is mainly den and Lewis [3] presented some biometric data on achieved and maintained with two exceptions. One unoperated monolateral congenital cataract, which patient had a late operation at the age of 11 months showed that there is a high axial length myopia in and suffered from secondary glaucoma. A second almost all of them, this was in agreement with other patient, who for the first 5 years responded well to data in experimental amblyopia in animals [4]. orthoptic treatment, after ab~olute non-compliance of patching had a drop of visual acuity to 0.05 (Fig. 1). INTRODUCTION
MATERIALS
The patients of the University eye clinic who were included in this study, underwent early operation for Please address all correspondence to: Dr Elisabeth Schulz, Abt. Pleoptik und Orthoptik, University Augenklinik Hamburg, MartinistraBe 52, D-2000 Hamburg 20, FRG. 0955-3681/90/040253+04 $03.00/0 © 1990 Bailliere Tindall
Bilateral cataracts
There is an age-dependent development, which implies that an increase in visual acuity with age 0.5 to 0.6 can be achieved (Fig. 2). In some cases there is an intraocular difference due to amblyopia, but orthEur J Implant Ref Surg, Vol2, December 1990
E. Schulz
254 Unilateral congenital cataracts 1.6 1.2!1 1.0 0.8 0.63 0.!1 ~
0.4
""
0.32
·;
.
a
·;;"
0.2 0.16 o.l o.o8
.. . ....
..
•••
I
~CI
c •
S.G.
77 ap II Mo.
o•L..W.
82 op 7 Mo.
• • F. T.
81
c.J.
~
oo
0.063
H
op 3 Mo.
82 op 4 Mo. I. D. ~ 80 op 4 Mo.
0.0!1
4
3
8
10
9
II
12
Age (yean)
Fig. 1 Visual acuity in early operated monolateral cataract vs. age. Filled symbols: phakic eye; open symbols: aphakic eye Bilateral congenital cataract a • A.L.. • S.B. 1.0 0.8 0.63
~
" "" 0 >•"
0.32 0.25
•
0.2 0.16
...
~
0.5 0.4
• •
;.
..
*
0.12!1
•i
.
~·
. •
• M.H. • S.R. •M.D. -lfR.G •
*".
ll
*
•
•
*
.
J
0.1
• B.N.
•
!
0.08 0.06!1 0.0!1 3
4
8
9
10
II
Age ( yearal
Fig. 2 Visual acuity development in early operated bilateral congenital cataract (seven patients). Equivalent symbols for right and left eyes; monocular and binocular visual acuity indicated by filled and open symbols respectively
optic treatment with part time occlusion ofthe better eye can be successful, as shown in Fig. 2 for patients BNandSR. Refractive changes
Assessment of refractive power in congenital cataract is usually performed by retinoscopy. The following data are taken from the clinical report of the patients. Refraction data thus obtained may not be exact in a strictly biometrical sense. This is due to
difficulties, especially in small children with inappropriate fixation in small pupillary opening and/ or secondary cataract and considerable nystagmus. In addition it will make a difference and give rise to some errors whether the refraction is obtained as an additional refraction over a fitted contact lens with high refractive power, over glasses of different vertex distance, and whether it is taken under general anaesthesia, when the visual axis has to be estimated in someway. The data of the group of bilateral cataracts may especially bear some errors. A few examples are illusEur J Implant Ref Surg, Vol2, December 1990
255
Development and Changes in Congenital Cataract Monoloterol congenital cataract
34
o
L.W.
• 1.0. o C.J .
• s.s.
• R.E. v
c
F. T.
S.G .
•r::
.!! u
8"u • ~
)I
"a.
•.
u ~ ~
12 I
IO
8
I
I
I
I
4 6 8 10 IZ Months
6
Z
3
4
5
6
7
8
9
10
II
Years
Fig. 3
Refractive power of contact lens correction us. age in seven patients operated on early for monolateral congenital cataract
trated below. A contact lens correction of +30 D will equal a spectacle correction of+ 22 D in 12 mm vertex distance, +20.6D in 15mm and 18.7D in 20mm vertex distance. A +35 D contact lens correction will equal a +24.6D, +23D or +20.6D spectacle correction respectively. So an 8 mm error in vertex distance will make a 3 to 4 D difference for the correction. Monolateral cataract
Refractive power ofthe contact lens correction for the far distance and for the aphakic eye is shown in Fig. 3 for seven patients. All patients show a considerable reduction of hyperopia some to rather myopic ranges of axial length (corneal curvature changed only little). This reduction of refraction may last up to early school age in four cases, two others seem to be rather stable from later pre-school age. The reduction of hyperopia is 7-14D, mean 9D. Two higher amblyopic patients, RE and ID, are less affected than the others. Bilateral cataract
The results of the longitudinal study in refractive power are shown in Fig. 4; one patient, HT, was implanted with an iris-fixated IOL during the first Eur J Implant Ref Surg, Vol2, December 1990
operation at the age of 8 months. This patient as well as JM suffered from Down's Syndrome. The first showed a tremendous reduction of hyperopia during follow-up, the second showed a 10 D reduction of hyperopia from month 11 to month 12 of age. Two patients, MD, who started with a rather low refractive power compared to the others, and IPK, who had been operated elsewhere and came to our clinic at the age of 1 year, had a rather stable refractive power during all the years of follow-up. In the latter, early data were not available. All other patients showed a considerable reduction of hyperopia mainly in the first year of life, except patient BN, whose refractive power decreased up to the age offour. CONCLUSION
It would seem that the initial questions can be answered in the following way. Refractive changes occur in most cases. For each individual case they are generally unpredictable concerning the onset, amount and time course. There may be over 10 D refractive change (e.g. in Down's Syndrome). In our series no data was available before the age of 3 months. The overall impression from our findings was that any kind of refractive surgery, implant or other, should be restricted to those cases in whom contact lens correction fails.
256
E. Schulz
: ~ ~:~: I.P.K
Bilateral congenital cataract
o o
• • A.H.T. M,Down
•
t
o.s.
9
10
• • J.M. • • N.Ue. • 0 M.E.
M. Down
,; ,; E E
..•
~
16
~ u
•
a.
14
• a.
12
•
..•
0
•
10
.'!: ~
u
8
•
6
~
a:
I I I I I 4 6 81012 Months
4
2
3
4 \5
2
Y:ara 7
8
II
~
Fig. 4 Refractive power of spectacle correction (vertex distance 12 mm) us. age in eight patients operated early for bilateral congenital cataract. Right and left eye: filled and open symbols respectively
REFERENCES 1 E. Schulz. Refractive changes and retarded visual development in aphakic children after operation for congenital cataract. In Detection and Measurement of Visual Impairment in Preverbal Children. Documenta Ophthalmologica Proceedings, Series 45. London, 1985,pp.260-267.
2 E.E. Birch and D.R. Stager. Prevalence of good visual acuity following surgery for congenital cataract. Arch. Ophthalmol., 106, 40-48 (1988). 3 G.K. von Noorden and R.A. Lewis. Ocular axial length in unilateral congenital cataract and blepharoptosis. Invest. Ophthalmol. Vis. Sci., 28,750-752 (1987). . 4 E. Raviola and T.N. Wiesel. An animal model of myopia. N. Engl. J. Med., 312, 1609-1615 (1985).
Eur J Implant Ref Surg, Vol2, December 1990