LETTERS TO THE JOURNAL
osity about the progress of my own macular degeneration, but now, in my seventies, I
should be happy to leave further development
and clinical trials to others who may think it worthwhile.
763
(Omega 5500) onto a screen to give an x 10
magnification, and the area of the optic disc
and disc pallor measured using a compensat
ing planimeter and expressed as relative units. The reproducibility of duplicate measure
Last year the local youth training work
ments (expressed as coefficient of variation,
were sold in aid of the Macular Disease
2.5% for the colour measurements and 3.9 +
shop3 kindly made three dozen PPs which Society's Research Fund.
mean/standard deviation x 100%) was 4.2 +
2.9% for the red free measurements.
The area of optic disc pallor (expressed as a
E. R. Ellis, AE, CEng, MIMechE
Riverside Cottage,
percentage of optic disc area) was 36.6 +
21A City Walls,
16.5% for the colour photographs, and 38.1 +
Chester CH1 1SB.
16.2% for the red-free photographs. There
References
mean values (p
1
was no significant difference between the
A. Chopdar, FRCS, Department of Ophthalmology, East Surrey Hospital.
2
E.
Gowler,
Chairman
of
the
Macular
Disease
Society. 3
Cheshire County Council, County Youth Workshop, Ellesmere Port.
=
0.95). The Spearman rank
correlation co-efficient between the colour
and
red-free
pallor
areas
was
r
=
0.89
(p 0.0001). Subjectively there was little differ
ence in the ease or difficulty with which the
pallor boundary was outlined with either the colour or red-free images.
Sir, Optic disc pallor measurement
The major ophthalmoscopic features of optic
Comment
nerve damage in glaucoma are pathological
Optic disc pallor area has previously been
studies indicate that the appearance of optic
roretinal rim areall and visual field 10ss!2 in
cupping and pallor of the disc.! Histological
disc pallor reflects loss of neural tissue and
changes in light transmission of the atrophic optic nerve.2.3 Thus disc pallor is a valuable
shown to be significantly correlated with neu
glaucoma. Measurement of pallor area can be
made from monoscopic disc photographs and
this represents an advantage over neuroreti
clinical sign in the assessment and manage
nal rim area measurement, which requires
subjects. A number of different techniques
to get a true representation of depth at the
ing colorimetry,4 densitometry,S planimetry,6
nuclear sclerosis, can affect the colour of the
sis.s-IO A review of the methods used shows
and red-free fundus photographs. Circular
ment of ocular hypertensive and glaucoma
have been used to measure disc pallor includ
photometr/ and computerised image analy
that several of the studies used colour photo
graphs,4,8,9 while others used black and white or monochromatic images.5.6,7,10
It is not
known how well the colour and monochro
stereoscopic views (preferably simultaneous)
optic nerve head. Lens opacities, in particular
optic disc affecting the quality of both colour
light polarisers have been suggested as a means of improving the quality of fundus imaging in cataractous eyes.13 Similarly, lens
opacities affect the quality of stereoscopic disc
matic pallor measurements correspond. To
photographs making it difficult to get topo
measured and correlated using colour and
field testing unreliable. The variety of tech
address this, the area of optic disc pallor was red-free fundus photographs.
Optic disc colour photographs (Zeiss fun
dus camera) of 25 ocular hypertensive and
glaucoma patients were used to give a wide
range of pallor values. The monochromatic
images were obtained by taking red-free photographs (Wratten 58 filter) of the colour
images. The 35 mm slides were projected
graphic measurements, and also make visual niques to measure pallor have used colour and monochromatic/black and white images inter
changeably without knowing how well the colour and monochromatic pallor measure
ments correlated. The results of this study
show that optic disc pallor area may be reliably and accurately measured from red free fundus photographs.
LETTERS TO THE JOURNAL
764
Colm O'Brien FRCS, FCOphth
factors which predispose to the development
Old Hall Street
been associated with maternal diabetes melli
St Paul's Eye Hospital Liverpool L3 9PF
References 1
2
Schwartz B: Cupping and pallor of the optic disc. Arch Ophthalmol1973, 89: 272-7. Quigley HA and Anderson DR: The histological basis of optic disc pallor in experimental optic
3
atrophy. Am J Ophthalmol1977, 83: 709-17. Quigley HA, Hohman RM, Addicks EM: Quantita tive study of optic nerve head capillaries in experi mental optic disc pallor. Am J Ophthalmol1982, 93: 689-99.
4
Gloster]: Colorimetry of the optic disc. Trans Oph thalmol Soc UK 1973, 93: 243-9.
5
Schwartz B and Kern]: Scanning microdensitometry of optic disc pallor in glaucoma. Arch ophthalmol 1977,95: 2159-65.
6
Schwartz B, Reinstein NM, Lieberman DM: Pallor of the optic disc. Quantitative photographic eval uation. Arch Ophthalmol1973, 89: 278-86.
7
Robert Y and Hendrikson P: Color appearance of the papilla in normal and glaucomatous eyes. Arch Ophthalmol1984, 102: 1772-5.
8
Nagin P, Schwartz B, Nanba K: The reproducibility of computerised analysis for measuring optic disc pallor in the normal optic disc. Ophthalmology 1985,92: 243-51.
9 Miller ]M and Caprioli ]: Videographic quantifica tion of optic disc pallor. Invest Ophthalmol Vis Sci 10
1988,29: 320-3. Cox M] and Wood IC]: Computer-assisted optic nerve head assessment. Ophthalmol Physiol Opt
11
1991, 11: 27-35. Tuulonen A, Airaksinen P], Schwartz B et al: Corre lation of optic disc pallor and neuroretinal rim area in glaucoma and ocular hypertension. Invest
12
Ophthalmol Vis Sci1990,31: 566. Schwartz B: Correlation of pallor of optic disc with asymmetrical visual field loss in glaucoma. XXII
13
Concilium Ophthalmologicum 1974,2: 632-8. Fariza E, ]alkh AE, Thomas ]V, O'Day T, Peli E, Acosta ]: Use of circularly polarised light in fun dus and optic disc photography. Arch Ophthalmol 1988, 106: 1001-4.
of ONH are unknown. The condition has
tus/post-mature birth7, young maternal age,8 first born children9 and maternal ingestion of drugs during pregnancy, especially alcohol.
We have carried out a questionnaire survey
study involving the mothers of 27 patients
with bilateral ONH. Patients were identified
from the records of the Royal Hospital for
Sick Children in Glasgow which is a referral centre for a population of 2.5 million. The aim
of the study was to gather information regard
ing the maternal history during pregnancy.
The study also included 65 mothers of age matched normal children. The main factors
reviewed
included
the
timing
birth,
smoking during pregnancy.
The results obtained regarding the timing
of birth demonstrated a slightly higher preva
lence of both premature and post-mature
birth in the patient group, the latter result agreeing with a previous report of slightly
raised prevalence of post-maturity in children
with ONH.9 Our results were also, as in that
report, not statistically significant. Our results
which
demonstrated lower
maternal age in mothers of patients with
ONH (25.5 years compared to 27.4 years in the normal group) were in accordance with
previous reports.8,9 However, this difference
was not statistically significant (0.2
osity about the progress of my own macular degeneration, but now, in my seventies, I
should be happy to leave further development
and clinical trials to others who may think it worthwhile.
763
(Omega 5500) onto a screen to give an x 10
magnification, and the area of the optic disc
and disc pallor measured using a compensat
ing planimeter and expressed as relative units. The reproducibility of duplicate measure
Last year the local youth training work
ments (expressed as coefficient of variation,
were sold in aid of the Macular Disease
2.5% for the colour measurements and 3.9 +
shop3 kindly made three dozen PPs which Society's Research Fund.
mean/standard deviation x 100%) was 4.2 +
2.9% for the red free measurements.
The area of optic disc pallor (expressed as a
E. R. Ellis, AE, CEng, MIMechE
Riverside Cottage,
percentage of optic disc area) was 36.6 +
21A City Walls,
16.5% for the colour photographs, and 38.1 +
Chester CH1 1SB.
16.2% for the red-free photographs. There
References
mean values (p
1
was no significant difference between the
A. Chopdar, FRCS, Department of Ophthalmology, East Surrey Hospital.
2
E.
Gowler,
Chairman
of
the
Macular
Disease
Society. 3
Cheshire County Council, County Youth Workshop, Ellesmere Port.
=
0.95). The Spearman rank
correlation co-efficient between the colour
and
red-free
pallor
areas
was
r
=
0.89
(p 0.0001). Subjectively there was little differ
ence in the ease or difficulty with which the
pallor boundary was outlined with either the colour or red-free images.
Sir, Optic disc pallor measurement
The major ophthalmoscopic features of optic
Comment
nerve damage in glaucoma are pathological
Optic disc pallor area has previously been
studies indicate that the appearance of optic
roretinal rim areall and visual field 10ss!2 in
cupping and pallor of the disc.! Histological
disc pallor reflects loss of neural tissue and
changes in light transmission of the atrophic optic nerve.2.3 Thus disc pallor is a valuable
shown to be significantly correlated with neu
glaucoma. Measurement of pallor area can be
made from monoscopic disc photographs and
this represents an advantage over neuroreti
clinical sign in the assessment and manage
nal rim area measurement, which requires
subjects. A number of different techniques
to get a true representation of depth at the
ing colorimetry,4 densitometry,S planimetry,6
nuclear sclerosis, can affect the colour of the
sis.s-IO A review of the methods used shows
and red-free fundus photographs. Circular
ment of ocular hypertensive and glaucoma
have been used to measure disc pallor includ
photometr/ and computerised image analy
that several of the studies used colour photo
graphs,4,8,9 while others used black and white or monochromatic images.5.6,7,10
It is not
known how well the colour and monochro
stereoscopic views (preferably simultaneous)
optic nerve head. Lens opacities, in particular
optic disc affecting the quality of both colour
light polarisers have been suggested as a means of improving the quality of fundus imaging in cataractous eyes.13 Similarly, lens
opacities affect the quality of stereoscopic disc
matic pallor measurements correspond. To
photographs making it difficult to get topo
measured and correlated using colour and
field testing unreliable. The variety of tech
address this, the area of optic disc pallor was red-free fundus photographs.
Optic disc colour photographs (Zeiss fun
dus camera) of 25 ocular hypertensive and
glaucoma patients were used to give a wide
range of pallor values. The monochromatic
images were obtained by taking red-free photographs (Wratten 58 filter) of the colour
images. The 35 mm slides were projected
graphic measurements, and also make visual niques to measure pallor have used colour and monochromatic/black and white images inter
changeably without knowing how well the colour and monochromatic pallor measure
ments correlated. The results of this study
show that optic disc pallor area may be reliably and accurately measured from red free fundus photographs.
LETTERS TO THE JOURNAL
764
Colm O'Brien FRCS, FCOphth
factors which predispose to the development
Old Hall Street
been associated with maternal diabetes melli
St Paul's Eye Hospital Liverpool L3 9PF
References 1
2
Schwartz B: Cupping and pallor of the optic disc. Arch Ophthalmol1973, 89: 272-7. Quigley HA and Anderson DR: The histological basis of optic disc pallor in experimental optic
3
atrophy. Am J Ophthalmol1977, 83: 709-17. Quigley HA, Hohman RM, Addicks EM: Quantita tive study of optic nerve head capillaries in experi mental optic disc pallor. Am J Ophthalmol1982, 93: 689-99.
4
Gloster]: Colorimetry of the optic disc. Trans Oph thalmol Soc UK 1973, 93: 243-9.
5
Schwartz B and Kern]: Scanning microdensitometry of optic disc pallor in glaucoma. Arch ophthalmol 1977,95: 2159-65.
6
Schwartz B, Reinstein NM, Lieberman DM: Pallor of the optic disc. Quantitative photographic eval uation. Arch Ophthalmol1973, 89: 278-86.
7
Robert Y and Hendrikson P: Color appearance of the papilla in normal and glaucomatous eyes. Arch Ophthalmol1984, 102: 1772-5.
8
Nagin P, Schwartz B, Nanba K: The reproducibility of computerised analysis for measuring optic disc pallor in the normal optic disc. Ophthalmology 1985,92: 243-51.
9 Miller ]M and Caprioli ]: Videographic quantifica tion of optic disc pallor. Invest Ophthalmol Vis Sci 10
1988,29: 320-3. Cox M] and Wood IC]: Computer-assisted optic nerve head assessment. Ophthalmol Physiol Opt
11
1991, 11: 27-35. Tuulonen A, Airaksinen P], Schwartz B et al: Corre lation of optic disc pallor and neuroretinal rim area in glaucoma and ocular hypertension. Invest
12
Ophthalmol Vis Sci1990,31: 566. Schwartz B: Correlation of pallor of optic disc with asymmetrical visual field loss in glaucoma. XXII
13
Concilium Ophthalmologicum 1974,2: 632-8. Fariza E, ]alkh AE, Thomas ]V, O'Day T, Peli E, Acosta ]: Use of circularly polarised light in fun dus and optic disc photography. Arch Ophthalmol 1988, 106: 1001-4.
of ONH are unknown. The condition has
tus/post-mature birth7, young maternal age,8 first born children9 and maternal ingestion of drugs during pregnancy, especially alcohol.
We have carried out a questionnaire survey
study involving the mothers of 27 patients
with bilateral ONH. Patients were identified
from the records of the Royal Hospital for
Sick Children in Glasgow which is a referral centre for a population of 2.5 million. The aim
of the study was to gather information regard
ing the maternal history during pregnancy.
The study also included 65 mothers of age matched normal children. The main factors
reviewed
included
the
timing
birth,
smoking during pregnancy.
The results obtained regarding the timing
of birth demonstrated a slightly higher preva
lence of both premature and post-mature
birth in the patient group, the latter result agreeing with a previous report of slightly
raised prevalence of post-maturity in children
with ONH.9 Our results were also, as in that
report, not statistically significant. Our results
which
demonstrated lower
maternal age in mothers of patients with
ONH (25.5 years compared to 27.4 years in the normal group) were in accordance with
previous reports.8,9 However, this difference
was not statistically significant (0.2
