We read with interest the paper by Tan et al. [1] on Charles Bonnet
Syndrome (CBS) in Asian patients. Their finding of a lower CBS prevalence
than European or North American surveys demands further investigation,
although this may reflect the stringent criteria of hallucination
complexity they used in making the diagnosis (thus excluding the commonest
CBS hallucinations of coloured blobs and gri...
We read with interest the paper by Tan et al. [1] on Charles Bonnet
Syndrome (CBS) in Asian patients. Their finding of a lower CBS prevalence
than European or North American surveys demands further investigation,
although this may reflect the stringent criteria of hallucination
complexity they used in making the diagnosis (thus excluding the commonest
CBS hallucinations of coloured blobs and grid-like ‘tesselloptic’
patterns [2,3]) and, as pointed out in the accompanying editorial comment,
the relatively low prevalence of macular disease in their cohort.
However, it is not this aspect of the report we found most intriguing - it
was the observation that CBS occurred with good acuity. In fact, 3 of the
4 CBS patients described had a degree of impairment which placed them at
risk for CBS (best eye acuity 0.3 or worse [4]). It is the remaining
patient (patient three, a 72 year old male) who is of particular
importance as his relative preservation of acuity bilaterally (20/30 RE,
20/40 LE) challenges the view that significant acuity loss is a
prerequisite for ‘ophthalmological’ visual hallucinations. This case
mirrors 4 patients we have recently studied with Charles Bonnet Syndrome
secondary to glaucoma and bilaterally good acuity. We describe the cases
below and offer a pathophysiological mechanism for the association.
In one sense, the finding that CBS occurs with preserved acuity is
hardly novel. As cited by Tan et al.[1], several previous reports have
found such an association. However, all is not as it seems, the term
Charles Bonnet Syndrome (CBS) being used in different ways by different
authors. Some use the term to describe visual hallucinations with insight,
irrespective of the presence of eye disease, age or clinical context [5,6].
Others use the term to describe the association of visual hallucinations
with age and intact cognition, without reference to eye disease or
hallucination phenomenology [7,8]. Under these definitions it is hardly
surprising that a patient with ‘CBS’ has preserved acuity, the patients in
these studies having a diverse range of conditions from delirium to
Parkinson’s disease and beyond. In contrast, ophthalmologists and
neurologists have used CBS to emphasise eye or visual pathway disease,
with the phenomenology of the hallucinations and age being of secondary
importance [9,10]. Although each definition of CBS has its merits, the ophthalmological definition reminds us best of Bonnet’s original
description and helps characterise a distinctive subgroup of visually
hallucinating patients with predicable prognosis and specific
pathophysiology [2,11]. However, even CBS as defined ophthalmologically
carries with it an inherent ambiguity: is it eye disease itself or the
loss of acuity that is the important factor? The consistent finding of
acuity loss as a risk factor [4,12,13] suggests the latter, or at least
that the central retina plays a key role in the underlying pathophysiological mechanism.
As part of a larger study into the visual phenomenology of CBS, we
have recruited 4 patients with advanced glaucoma (3 POAG and 1 chronic
narrow angle) but preserved visual acuity. The age range of the patients
was 81 to 91, 3 men and 1 woman. Their visual acuities ranged from 6/6 to
6/12 monocularly with all patients having 6/9 or better in their better
eye. All had extensive field defects bilaterally and cup to disc ratios of
0.8 or greater in both eyes. 2 patients had bilateral trabeculectomies now
off treatment, one was on g.bimatoprost and g.trusopt to both eyes and one
on g.timolol 0.25% to both eyes. 2 patients were bilaterally pseudophakic.
The patient with chronic narrow angle glaucoma had previous surgical
iridectomies. The duration of their hallucinations ranged from 6 months to
6 years. 3 patients hallucinated in colour and one in black and white. The
most common hallucination was of tessellopsia [2] experienced by all the
patients, with 2 patients seeing, in addition, formed buildings and 2
patients, letter-like shapes. There were also single reports of
hallucinations of groups of people, animals, branching shapes
(dendropsia [2]) and one patient described visual allesthesia [14]. In three
of the patients the hallucinations encompassed the entire visual field, in
the fourth they were restricted to the visual field defect. None had
hallucinations in other sensory modalities and all had insight into the
nature of the experiences. The phenomenology of the hallucinations and the
relative frequency of the different hallucination categories are
consistent with previous descriptions of ophthalmologically-defined
CBS [2,3]. Non-ophthalmological causes of visual hallucinations [2,3] were
excluded. As far as we are aware this is the largest case series of
patients with visual hallucinations secondary to eye disease and
bilaterally preserved visual acuity yet to be reported.
Current aetiological theories of CBS emphasise the importance of
deafferentation [15] (both ‘physiological’ through ganglion cell loss and
‘functional’, e.g. related to blindfolding or cataract), the loss of
visual input resulting in a change in cortical excitability [2]. Although
it has been assumed that deafferentation of sufficient severity to
precipitate CBS implies a consequent loss of acuity, our cases and that of
Tan et al.[1] suggest otherwise. Patients with advanced glaucoma can have
a significant degree of ganglion cell loss and consequent physiological deafferentation without a loss of acuity, placing them at risk for CBS.
This contrasts with age related macular disease where the loss of central
retinal ganglion cells leads, indirectly, to an association of CBS with
acuity loss. We conclude that reduced acuity is not a necessary
prerequisite for ophthalmologically-defined CBS and that ophthalmologists
should be aware that patients with preserved acuity but significant
deafferenting ocular disease are at risk of the syndrome.
References
(1) Tan CSH, Lim VSY, Ho DYM, Yeo E, Ng BY, Au Eong KG. Charles Bonnet
syndrome in Asian patients in a tertiary ophthalmic centre. Br J
Ophthalmol 2004; 88: 1325-1329.
(2) ffytche DH, Howard RJ. The perceptual consequences of visual loss:
positive pathologies of vision. Brain 1999; 122: 1247-1260.
(3) Santhouse AM, Howard RJ, ffytche DH. Visual hallucinatory syndromes
and the anatomy of the visual brain. Brain 2000; 123: 2055-2064.
(4) Teunisse RJ, Cruysberg JR, Verbeek AL, Zitman FG. The Charles
Bonnet syndrome: a large prospective study in the Netherlands. Br J
Psychiatry 1995; 166: 254-257.
(5) Damas-Mora J, Skelton-Robinson M, Jenner FA. The Charles Bonnet
Syndrome in perspective. Psychol Med 1982; 12: 251-261.
(6) Gold K, Rabins PV. Isolated visual hallucinations and the Charles
Bonnet syndrome: a review of the literature and presentation of six cases.
Compr Psychiatry 1989; 30: 90-98.
(7) Podoll K, Osterheider M, Noth J. Das Charles Bonnet-Syndrom.
Fortschr. Neurol. Psychiat. 1989; 57: 43-60.
(8) de Morsier G. Le syndrome de Charles Bonnet: hallucinations
visuelles des vieillards sans deficience mentale. Annales Medico-
Psychologiques 1967; 125: 677-702.
(9) Manford M, Andermann F. Complex visual hallucinations. Clinical and
neurobiological insights. Brain 1998; 121: 1819-1840.
(10) Menon GJ, Rahman I, Menon SJ, Dutton GN. Complex visual
hallucinations in the visually impaired: the Charles Bonnet Syndrome. Surv
Ophthalmol 2003; 48: 58-72.
(11) ffytche DH. Visual hallucination and illusion disorders: a
clinical guide. Advances Clin Neurosci Rehab 2004; 4: 16-18.
(12) Holroyd S, Rabins PV, Finkelstein D, Nicholson MC, Chase GA,
Wisniewski SC. Visual hallucinations in patients with macular
degeneration. Am J Psychiatry 1992; 149: 1701-1706.
(13) Scott IU, Schein OD, Feuer WJ, Folstein MF. Visual hallucinations
in patients with retinal disease. Am J Ophthalmology 2001; 131: 590-598.
(14) Girkin CA, Miller NR. Central disorders of vision in humans. Surv
Ophthalmol 2001; 45: 379-405.
(15) Burke W. The neural basis of Charles Bonnet hallucinations: a
hypothesis. J Neurol Neurosurg Psychiatry 2002; 73: 535-541.
The paper by Munkvitz et al.
deals with the interpretation of the Nerve Fiber Analyzer (NFA) printout
in a
sample of healthy and advanced or early glaucomatous eyes. Three
independent readers, at different levels of clinical experience,
classified GDx printouts while being masked with respect to the eye
condition and optic
disc pictures. A questionnaire was used by readers to determine
diagnosis
but n...
The paper by Munkvitz et al.
deals with the interpretation of the Nerve Fiber Analyzer (NFA) printout
in a
sample of healthy and advanced or early glaucomatous eyes. Three
independent readers, at different levels of clinical experience,
classified GDx printouts while being masked with respect to the eye
condition and optic
disc pictures. A questionnaire was used by readers to determine
diagnosis
but no additional information about this procedure is provided. To the
best of our knowledge there is no consensus regarding a standardized
procedure
to evaluate the GDx printout. Furthermore, other than color-coded RNFL
thickness map, absolute values of GDx parameters and their levels of
probability (<_10 or="or" _5="_5" criteria="criteria" used="used" to="to" classify="classify" examined="examined" eyes="eyes" are="are" not="not" defined.="defined." an="an" even="even" greater="greater" flaw="flaw" is="is" anterior="anterior" segment="segment" birefringence="birefringence" compensation="compensation" and="and" its="its" evaluation="evaluation" by="by" means="means" of="of" macular="macular" area="area" imaging="imaging" _1.="_1." the="the" authors="authors" employed="employed" nfa="nfa" with="with" fixed="fixed" corneal="corneal" whose="whose" limited="limited" ability="ability" remove="remove" unwanted="unwanted" in="in" most="most" has="has" been="been" demonstrated="demonstrated" previously="previously" _23="_23" but="but" they="they" did="did" image="image" area.="area." thus="thus" rnfl="rnfl" thickness="thickness" may="may" have="have" overestimated="overestimated" up="up" _20="_20" a="a" certain="certain" portion="portion" studied="studied" _3.="_3." apart="apart" from="from" significantly="significantly" reduced="reduced" sensitivity="sensitivity" this="this" severely="severely" affect="affect" gdx="gdx" printout="printout" separate="separate" healthy="healthy" glaucomatous="glaucomatous" _45="_45" due="due" artificially="artificially" thick="thick" rnfl.="rnfl." spite="spite" values="values" were="were" _100="_100" _90="_90" for="for" reader="reader" _1="_1" _2="_2" respectively.="respectively." at="at" least="least" advanced="advanced" glaucoma="glaucoma" these="these" extremely="extremely" high="high" could="could" be="be" related="related" mean="mean" defect="defect" mentioned="mentioned" text="text" it="it" quite="quite" surprising="surprising" that="that" early="early" nfb="nfb" defects="defects" correctly="correctly" identified="identified" classified="classified" all="all" cases.="cases." methodological="methodological" problems="problems" limit="limit" significance="significance" impact="impact" otherwise="otherwise" interesting="interesting" paper.="paper." p="p"/>References
(1) Greenfield DS, Knighton RW, Huang XR. Effect of corneal
polarization axis on assessment of retinal nerve fiber layer thickness
by
scanning laser polarimetry. Am J Ophthalmol 2000;129:715-22.
(2) Weinreb RN, Bowd C, Greenfield DS, Zangwill LM. Measurement of
the
magnitude and axis of corneal polarization with scanning laser
polarimetry. Arch Ophthalmol 2002;120:901-6.
(3) Choplin NT, Zhou Q, Knighton RW. Effect of individualized
compensation for anterior segment birefringence on retinal nerve fiber
layer assessment as determined by scanning laser polarimetry.
Ophthalmology 2003;110:719-25.
(4) Greenfield DS, Knighton RW, Feuer WJ, Schiffmann JC, Zangwill LM,
Weinreb RN. Correction for corneal polarization axis improves the
discriminating power of scanning laser polarimetry. Am J Ophthalmol
2002;134:27-33.
(5) Bowd C, Zangwill LM, Berry CC, Blumenthal EZ, Vasile C, Sanchez-
Galeana C et al. Detecting early glaucoma by assessment of retinal nerve
fiber layer thickness and visual function. Invest Ophthalmol Vis Sci
2001;42:1993-2003
Developmental mosaicism in the eye may follow the “lines of
Blaschko”
Ruggieri M et al. nicely described the ophthalmological manifestations in
segmental neurofibromatosis type 1 [1]. They postulated that segmental NF1
is a somatic mosaicism for the NF1-gene expressing two different
embryological tissues in the eye.
Previously we described a patient with unilateral sectorial
hyperpigmented ski...
Developmental mosaicism in the eye may follow the “lines of
Blaschko”
Ruggieri M et al. nicely described the ophthalmological manifestations in
segmental neurofibromatosis type 1 [1]. They postulated that segmental NF1
is a somatic mosaicism for the NF1-gene expressing two different
embryological tissues in the eye.
Previously we described a patient with unilateral sectorial
hyperpigmented skin lesions on his left shoulder and additional grouped
CHRPE in the left eye. These sectorial pigmentations were also noticed
during the first months of life and did not correspond to the distribution
of cutaneous nerves (dermatomes) [2]. Pigmentary mosaicism of the human
skin follow well-established segmental archetypes and were published by
the dermatologist Alfred Blaschko in 1901. He emphasized that these
“nevus lines” could neither be related to the
distribution of the nerves nor to vascular or lymphatic structures of the
skin [3].
These “lines of Blaschko” therefore reflect the dorso-
ventral outgrowth of precursor of the skin and may manifest the stream,
distribution, migration and proliferation of embryonic tissue. They
possibly originate during early embryogenesis by various genetic
mechanisms including postzygotic mutations, functional X-chromosomal
mosaicism, gametic halfchromatid mutations or loss of a heterozygosity
(LOH). If one of these events occurs, both homozygosity or heterozygosity
may predispose to sectorial pigmentation of these somatic cells. The
distinct stem-cell clones may give rise to the observed sectorial
mosaicism [4-5].
The precise pattern of the cutaneous lines of Blaschko
on the face, neck and trunk of the body were reported by Happle et al.
after observing numerous clinical examples of segmental skin disorders
[6].
Analogous patterns for the “lines of Blaschko” in the
eye [7] were described for heterozygous women with one randomly
inactivated X-chromosome (Lyonization) for X-linked Lowe-Syndrome
exhibiting segmental cataracts [8] or X-linked ocular albinism with stria-
like patchy fundus hypopigmentations with orientation toward the optic
nerve [9]. Recently we reviewed the literature over a period of 130 years
and identidied 41 publications with grouped congenital hypertrophy of the
retinal pigment epithelium (CHRPE). The sectorial pigmentations radiated
in a crescent shape from the optic nerve towards the periphery, providing
evidence, that there was no causal relationship to the retinal nerve fiber
system. We suggested that these lesions may follow developmental lines in
the eye analogous to the cutaneous lines of Blaschko. The sectorial
pattern of the neuroepithelial pigment epithelial in grouped CHRPE may
therefore reflect the outgrowth and migration of RPE-cells during
embryogenesis [10].
The important findings by Ruggieri M et al. give
further evidence, that two different embryological cellular clones may
present sectorial mosaicism in the eye following the lines of Blaschko.
References
(1) Ruggieri M, Pavone P, Polizzi A, Di Pietro M, Scuderi A, Gabriele A,
Spalice A, Iannetti P. Ophthalmological manifestations in segmental
neurofibromatosis type 1. Br J Ophthalmol 2004;88:1429-1433
(2) Meyer CH, Freyschmidt-Paul P, Happle R, Kroll P. Unilateral linear
hyperpigmentation of the skin with ipsilateral sectorial hyperpigmentation
of the retina. Am J Med Gen 2004;126A:89-92.
(3) Blaschko A. Die Nervenverteilung in der Haut in ihrer Beziehung zu den
Erkrankungen der Haut. 1901; Wien-Leipzig, W. Braumüller
(4) Happle R. Transposable elements and the lines of Blaschko: A new
perspective. Dermatology 2002;204;4-7.
(5) Happle R. Loss of heterozygosity in human skin. J Am Acad Dermantol
1999;41:143-61.
(6) Happle R, Assim A. The lines of Blaschko on the head and neck. J Am
Acad Dermatol 2001;44:612-5.
(7) Rott HD. Extracutaneous analogies of Blaschko lines. Am J Med Gen
1999;85:338-341.
(8) Happle R, Küchle HJ. Sectorial cataract: a possible explanation
Lyonisation. Lancet 1983;2:919-20.
(9) Rott HD, Rix R. Fundus changes in a carrier women for X-linked ocular
albinism: a proof of Lyon’s hypothesis in man. Klin Monatsbl
Augenheilkd 1984;184:128-9.
(10) Meyer CH, Rodrigues EB, Mennel S, Schmidt JC, Kroll P. Grouped
congenital hypertrophy of the retinal pigment epithelium follows
developmental patterns of pigmentary mosaicism. Ophthalmology (accepted)
We thank Dr Masood for his interest in our manuscript [1]. Clearly in
some cases of giant cell arteritis (GCA), treatment with high dose
corticosteroids alone is insufficient. The use of adjunctive heparin
proved to be beneficial in our patient, although the reason is not clear [1]. Thrombocytosis has been shown to occur in a large percentage of patients
with GCA [2, 3]. However, there is no convin...
We thank Dr Masood for his interest in our manuscript [1]. Clearly in
some cases of giant cell arteritis (GCA), treatment with high dose
corticosteroids alone is insufficient. The use of adjunctive heparin
proved to be beneficial in our patient, although the reason is not clear [1]. Thrombocytosis has been shown to occur in a large percentage of patients
with GCA [2, 3]. However, there is no convincing evidence that thrombocytosis plays a direct role in the ischemic complications of GCA
[3].
While anticoagulation may have been responsible for the improvement
of blood flow in our patient, other biochemical activities of heparin such
as prevention of inflammation may have also been at work. The value of
adjunctive aspirin therapy may not lie with its anti-thromobotic effect,
but rather with an interruption of the inflammatory cascade.
While the preliminary data regarding the value of adjunctive aspirin
use in the treatment of GCA is compelling [4], we believe that there is
insufficient evidence at this time to place all patients on adjunctive
aspirin therapy. We advocate further research to compare the
effectiveness the combination of corticosteroid and aspirin treatment
versus corticosteroid therapy alone.
References
(1) Buono LM, Foroozan R, de Virgiliis M, Savino PJ: Heparin therapy
in giant cell arteritis. Br J Ophthalmol 2004, 88:298-301.
(2) Foroozan R, Danesh-Meyer H, Savino PJ, et al.: Thrombocytosis in
patients with biopsy-proven giant cell arteritis. Ophthalmology 2002,
109:1267-71.
(3) Costello F, Zimmerman MB, Podhajsky PA, Hayreh SS: Role of
thrombocytosis in diagnosis of giant cell arteritis and differentiation of
arteritic from non-arteritic anterior ischemic optic neuropathy. Eur J
Ophthalmol 2004, 14:245-57.
(4) Nesher G, Berkun Y, Mates M, et al.: Low-dose aspirin and
prevention of cranial ischemic complications in giant cell arteritis.
Arthritis Rheum 2004, 50:1332-7.
We thank Drs. Kymes and Frick for their excellent letter regarding
utility analysis as a health-related quality of life instrument. We agree
that the use of primarily function-based quality of life instruments such
as the NEI-VFQ-25 may result in missing many important variables in the
quality of life arena, as well as limit applicability across all
diseases.1 In contrast, preference-based quality of...
We thank Drs. Kymes and Frick for their excellent letter regarding
utility analysis as a health-related quality of life instrument. We agree
that the use of primarily function-based quality of life instruments such
as the NEI-VFQ-25 may result in missing many important variables in the
quality of life arena, as well as limit applicability across all
diseases.1 In contrast, preference-based quality of life instruments such
as utility analysis, are applicable across all diseases and encompass all
variables that comprise quality of life, as well as the weighting of those
variables. Of great additional importance is the fact that preference-
based instruments can be used in healthcare economic analyses, especially
utility analysis, while most function-based instruments have not been
successfully used [1,2].
Concerning the use of time trade-off and standard gamble utility
analysis, we have found that the time trade-off methodology is easier for
patients to comprehend and also is more sensitive to milder health states
since there is risk aversion to the consequence of immediate death
associated with the standard gamble variant [1,2]. Froberg and Kane3 have
also shown that the time tradeoff method of utility has greater test-
retest reliability, intra-rater reliability and inter-rater reliability
than standard gamble methodology. In our experience, time trade-off
utilities generally demonstrate better construct validity1 and a wider
range between pre-intervention and post-intervention values than standard
gamble utilities, thus resulting in more favourable cost-utility analysis,
rather then less favourable analyses.
In regard to quality of life respondents, we remain firm in our
adherence to the fact that a basic pillar of value-based medicine is the
use of utility values obtained from respondents with a health state in
question [1,2]. We have found that utility value diminution in patients who
actually have age-related macular degeneration ranges from 103% to 750%
greater than the decrement estimated by treating ophthalmologists for the
same condition [4,5]. This has been noted as well for non-ophthalmologic
health states.6
We respectfully disagree that community utility values generally
overestimate the degree to which a disease decreases quality of life. In
contrast, we and others [4-9] have noted that community and provider
participants asked to evaluate the quality of life associated with a
health state using utility value analysis generally underestimate the
decrement in quality of life as compared to patients with that health
state. In essence, patients who have lived with a health state are those
best able to ascertain the quality of life associate with that health
state. And it is usually worse than others imagine.
In conclusion, we thank Drs. Kymes and Frick for their interest and
fine comments and look forward to additional awareness in the arena of
value-based medicine. As increasing numbers of those who allocate
healthcare resources become aware that value-based medicine allows for
higher quality care (by incorporating quality of life parameters that
evidence-based primary clinical trials often ignore) and the most
efficient use of resources, it will play a considerably greater role in
the delivery of cost-effective, quality healthcare. When that takes place,
all will benefit.
References
(1) Brown MM, Brown GC, Sharma, S. Evidence-Based to Value-Based
Medicine. AMA Press (in press).
(2) Brown MM, Brown GC, Sharma S, Landy J. Health care economic analyses
and value-based medicine. Surv Ophthalmol 2003;48:204-223.
(3) Froberg DG, Kane RL. Methodology for measuring health state
preferences. II. Scaling methods. J Clin Epidemiol. 1989;42:459–471.
(4) Brown GC, Brown MM, Sharma S. Difference between ophthalmologist and
patient perceptions of quality-of-life associated with age-related macular
degeneration. Can J Ophthalmol 2000;35:27-32.
(5) Brown GC, Brown MM, Sharma S, Roth Z, Campanella J, Beauchamp G. The
burden of age-related macular degeneration. A value-based analysis. Curr
Opin Ophthalmol (in press).
(6) Fryback DG, Dasbach EJ, Klein R, Klein BEK, Dorn N, Peterson K, Martin
PA. The Beaver Dam Outcomes Study: initial catalog of health-state quality
factors. Med Dec Making. 1993;13:89–102.
(7) Stein JD, Brown MM, Brown GC, Sharma S, Hollands H. Quality of life
with macular degeneration. Perceptions of patients, clinicians and
community members. Brit J Ophthalmol 2003;87:8-12.
(8) Landy J, Stein JD, Brown GC, Brown MM, Sharma S. Patient, community and
clinician perceptions of the quality of life associated with diabetes
mellitus. Medical Science Monitor 2002;8:543-548.
(9) Sharma S, Brown GC, Brown MM, Hollands H, Robbins R, Shah G. Validity
of the time trade-off and standard gamble methods of utility assessment in
retinal patients. Br J Ophthalmol 2002;86:493-496.
We read with interest the article by Ebner et al [1] investigating the
efficacy of periocular triamcinolone for the treatment of Thyroid Associated
Ophthalmopathy (TAO) and the presence of ocular or systemic adverse effects also
previously published in 2001 [2]. The study used patients with TAO of less than
6 months duration previously untre...
We read with interest the article by Ebner et al [1] investigating the
efficacy of periocular triamcinolone for the treatment of Thyroid Associated
Ophthalmopathy (TAO) and the presence of ocular or systemic adverse effects also
previously published in 2001 [2]. The study used patients with TAO of less than
6 months duration previously untreated, and assumed that the activity of the TAO
would be equal.
However large differences are apparent in both the demographics (a 78 year
old presenting with new onset TAO, and the use of an 11 year old child both
raised interesting scientific and ethical questions.) and the area of diplopia
at baseline suggesting baseline activity was not equal between groups. No
mention was made of either smoking or systemic medications used, both of which
are factors affecting the activity of TAO, and the subsequent measurement of the
potential systemic adverse effects of intraorbital triamcinolone. The main
measure of the local effect of triamcinolone was the area of single vision
obtained on a Goldmann perimeter, but the use of a 2-IV size light and the
measurement of “summation of angular points” is unclear.
The standard Goldmann nomenclature generally used designates a Roman numeral
for target size, and a combination of a number and letter to signify target
brightness and intensity. A 2-IV suggests a 4.51mm diameter light was used but
the brightness and intensity measure are not evident. The optimal size is a spot
subtending an angle of 2° to help discern the point of diplopia; a size IV only
subtends an angle of 0.86°and maybe to small to discriminate accurately. The
summation of angular points method to assess the area of single vision on the
graph obtained does not seem logical. Why not calculate the area within the
graph? No history of either prior strabismus or suppression seems to have been
elicited from the patients that would have a large effect on the results.
Both graphs shown demonstrate a large number of point readings taken
superiorly with only relatively few inferiorly, making the graph area a less
reliable measure. A more suitable method may have been a baseline independent
orthoptic assessment with serial Lees screen or Lister perimeter measurements,
and the adoption of Bagolini’s glasses to minimise suppression. The effects of
triamcinolone locally were measured with exophthalmometry, optic disc appearance
(normal, papilloedema, atrophy), ocular motility assessment and intraocular
pressure (IOP). The authors demonstrated in fig.3 an example of improved
cosmesis obtained but failed to measure this during the study, with perhaps
serial photographs [4]. Exophthalmometry values were not published, but any
change was stated to be not statistically significant.
The authors failed to explain why they thought the significant difference
between the areas of no diplopia demonstrated between the treatment and control
group were not supported by either a significant change in either proptosis or
extra ocular muscle diameter (except superior rectus) both of which are good
clinical indicators of TAO activity. Systemically the effect of triamcinolone
was measured by recording the body weight, blood pressure and various blood
tests at baseline, week 10 and week 24. Single point measurement of these
variables is unlikely to provide statistically significant information
especially when confounding factors such as systemic medications taken are
unknown.
References
(1) Ebner R, Devoto M,Weil D et al. Treatment of thyroid associated
ophthalmopathy with periocular injections of triamcinolone. Br J Ophthalmol
2004;88:1380-1386.
(2) Ebner R, Devoto M,Weil D et al. Tratamiento de la oftalmopatia asociada a
distiroidismo con triamcinolona periocular . Arch Oftalmol Bs As 2001;76:55-66.
(3) Dickinson AJ, Perros P, :Controversies in the clinical evaluation of
active thyroid associated thyroid orbitopathy. Clin Endocrinol 2001;55:283 -303.
We appreciate the comments of Sridhar et al. regarding our letter:
“The role of corticosteroids in fungal keratitis: a different view”
published in your journal [1]. The authors comment on our recommendation
for a gradual tapering of corticosteroids in cases where steroids were
used for the treatment of initially misdiagnosed fungal corneal
infections.
We appreciate the comments of Sridhar et al. regarding our letter:
“The role of corticosteroids in fungal keratitis: a different view”
published in your journal [1]. The authors comment on our recommendation
for a gradual tapering of corticosteroids in cases where steroids were
used for the treatment of initially misdiagnosed fungal corneal
infections.
As mentioned in our cases report the use of corticosteroids in fungal
corneal ulcers is a subject of active debate [2,3]. There is no evidence
that in cases of corneal infections treated with effective antifungals and
steroids the penetration of fungus is made worse even if the antifungals
are considered in vitro fungistatic. Dr Sridhar et al. brings to our
attention the well known theoretical problems of corticosteroids in fungus
infections that prompted us to immediatelly discontinue the steroids.
Despite theoretical disadvantages we need to emphasize that stopping
steroids made corneas perforate creating a much greater apparent problem
than these theoretical considerations of which we were quite aware.
The point of our letter is that the cessation of steroids in fact
caused acute severe worsening and perforation of the cornea. We think that
in cases of severe fungal infections, as these we tried to treat, the
cautious use of steroids with immediate tapering and close monitoring of
ulcer progression could halt the infectious process and benefit the
patient until the antifungal treatment will be effective. Any other use of
steroids in fungal corneal infections could increase the fungal load and
is not clearly justified.
References
(1) Peponis V, J B Herz JB, and H E Kaufman HE The role of
corticosteroids in fungal keratitis: a different view. Br J Ophthalmol
2004; 88: 1227
(2) Pineda R, Dolhman CH. The role of steroids in the management of
Acanthamoeba keratitis, fungal keratitis and epidemic
keratoconjunctivitis. Int Ophthalm Clin. 1994;34(3):19-31.
(3) Schreiber W, Olbrisch A, Vorwerk CK, et al. Combined topical
fluconazole and corticosteroid treatment for experimental Candida albicans
keratomycosis. Invest Ophthalm Vis Sci. 2003;44:2634-43.
We read the interesting article by L Wickham and associates,
“Vitrectomy and gas for inferior break retinal detachments: are the
results comparable to vitrectomy, gas and scleral buckle?” [1]. They have compared the results of vitrectomy and gas without scleral buckle (Group A) with, vitrectomy and
gas with scleral buckle (Group B) for inferior break retinal detachments.
We would like to point out to a...
We read the interesting article by L Wickham and associates,
“Vitrectomy and gas for inferior break retinal detachments: are the
results comparable to vitrectomy, gas and scleral buckle?” [1]. They have compared the results of vitrectomy and gas without scleral buckle (Group A) with, vitrectomy and
gas with scleral buckle (Group B) for inferior break retinal detachments.
We would like to point out to a possible error in the results section.
The authors have shown the distribution of retinal breaks using Venn
diagrams. Figure 1 shows that 16 patients in Group A had breaks confined
to 4-8 o’clock, 12 patients had breaks in 4-8 o’clock and 12-4 o’clock, 1
had breaks in 4-8 o’clock and 8-12 o’clock and breaks were scattered all
around in 1 patient. This comes to a total of 30 patients as against 41
patients included in Group A. This possible error in the diagram gives a
false impression that, Group B patients had retinal breaks that were more
widely distributed and also probably had more number of retinal breaks in
total. We are curious to know about this.
References
(1) L Wickham, M Connor, GW Aylward. Vitrectomy and gas for inferior
break retinal detachments: are the results comparable to vitrectomy, gas
and scleral buckle? Br J Ophthalmol 2004; 88: 1376-9.
In a fine recent editorial, Drs. Melissa and Gary Brown raised issues
at the nexus of health policy and clinical science [1]. As utility
assessment is relatively new to the visual sciences, understanding both
the assumptions behind this work and the consequences of relaxing those
assumptions is essential for high quality research and appropriate
interpretation of the results.
In a fine recent editorial, Drs. Melissa and Gary Brown raised issues
at the nexus of health policy and clinical science [1]. As utility
assessment is relatively new to the visual sciences, understanding both
the assumptions behind this work and the consequences of relaxing those
assumptions is essential for high quality research and appropriate
interpretation of the results.
The use of community-elicited utilities (i.e., including people not
suffering the disease in the elicitation study) in economic evaluation
should be given more than minimal consideration. Economic evaluations are
intended to inform health policy makers by assessing the value society
places on the cure or prevention of disease. Community-based utilities
typically reflect larger estimates of utility loss than those elicited
from patients and result in a more favourable analysis of the cost-
effectiveness of preventive interventions than those relying on patient-
elicited utilities [2]. At the same time, estimating community-elicited
utilities requires the development of easily understood scenarios to
assist community members in understanding life with the disease [3], thus,
many investigators prefer to rely on patient-elicited utilities. Rather
than dismiss this approach, economic evaluation in ophthalmology would be
greatly facilitated by a catalogue of community-elicited utilities related
to ocular diseases developed through the standard gamble or time trade-off
methods or responses to health status questionnaires that include
algorithms to estimate health utilities.
While the Browns caution against the use of functionally based health
-related quality of life instruments (e.g., the NEI-VFQ) in economic
evaluation, we would like to offer an alternative explanation for this
concern. Most disease specific instruments are based in psychometric
theory and designed to measure change in the patients self-reported health
status in investigator defined domains [4]. Domain scores do not reflect
the importance the respondent assigns to the activities, but scoring
algorithms developed by the instrument designer. The result is a metric
that is often meaningful to clinicians, but does not reflect the value the
patient or society places on the health state. This limits generalizability across disease groups, as well as investigators’ ability
to comment on the most efficient way to screen for, or treat, an
ophthalmic condition affecting multiple areas of physical, mental or
emotional function.
Finally, the standard gamble elicitation method should not be
dismissed off-handedly. More frequent use of the time trade-off reflects
the method’s intuitive appeal rather than theoretical superiority. As
opposed to the time-tradeoff in which the anchor event (i.e., death,
blindness, etc.) occurs in the future, in the standard gamble the event is
immediate. This provides an estimate of the person’s risk preference
unconfounded by time. The time trade-off consistently results in higher
estimates of utility loss than the standard gamble [5,6] and resulting in
less favourable cost-effectiveness results for preventing the condition.
We hope that our comments will help future work to be pragmatic and
as theoretically sound as possible. Understanding the theoretically
optimal methods and the need to make practical accommodations are
important if we are to avoid overstating the quality of our methods or the
value of our findings.
Steven M. Kymes, Ph.D.
Washington University School of Medicine
Department of Ophthalmology and Visual Sciences
Kevin D. Frick, Ph.D.
Johns Hopkins Bloomberg School of Public Health
Department of Health Policy and Management
References
(1) Brown MM, Brown GC. Value based medicine: Let's get it right.
British Journal of Ophthalmology 2004;88(8):979.
(2) Krahn MD, Ritvo P, Irvine J, Tomlinson G, Bremmer KE, Bezjak A, et
al. Patient and community preferences for outcomes in prostate cancer:
Implications for clinical policy. Medical Care 2003;41(1):153-64.
(3) Gold MR, Siegel JE, Russell LB, Weinstein MC. Cost-Effectiveness
in Health and Medicine. 1 ed. New York: Oxford University Press, 1996.
(4) Mangione CM, Lee PP, Gutierriez PR, Spritzer KL, Berry S, Hays RD.
Development of the 25-Item National Eye Institute Visual Function
Questionnaire. Archives of Ophthalmology 2001;119(7):1050-8.
(5) Salomon JA, Murray CJL. A multi-method approach to measuring
health-state valuations. Health Economics 2004;13:281-90.
(6) Jampel HD. Glaucoma Patients' Assessment of Their Visual Function
and Quality of Life. Transactions of the American Ophthamological Society
2001;99:301-17.
We thank the BJO for publishing our Letter to the Editor regarding
appending authors' qualifications [1] and for inviting correspondence
from
its readership on the issue in the editorial "Who is Ivan Schwab?"[2].
The editors wisely remind us that medical authorities have
suppressed
important findings by lesser-known authors, using the notable example of
Semmelweis. Even today, critical new info...
We thank the BJO for publishing our Letter to the Editor regarding
appending authors' qualifications [1] and for inviting correspondence
from
its readership on the issue in the editorial "Who is Ivan Schwab?"[2].
The editors wisely remind us that medical authorities have
suppressed
important findings by lesser-known authors, using the notable example of
Semmelweis. Even today, critical new information remains vulnerable to
suppression by authorities, medical or otherwise. Perhaps the most
memorable rejection was that of Novotny and Alvis whose seminal work on
fluorescein angiography was rejected by the American Journal of
Ophthalmology in 1960 [3].
We agree with the editors that publication of an article should be
based on its scientific merit, not on its authors' qualifications or
eminence. We would emphasise that publication is an editorial
prerogative
based on advice from reviewers, who are a select group, rather than from
a
journal's readership. In our modern age, the editorial decision to
publish
an article in a Medline-indexed journal equates to enduring world-wide
dissemination. Therefore, we agree with the proposal that authors' names
and
qualifications should be masked from reviewers. We would go even further
to suggest that this information, and the authors' institutional
affiliations, should also be masked from the editorial board, until a
preliminary decision is made regarding publication. This would ensure
the
primacy of the article's scientific content, making it more likely that
first-rate articles from unfamiliar and little-known authors are
published
at the expense of second-rate articles from eminent authors.
In contrast to the function of a reviewer, the task of the reader
is, in our opinion, facilitated by a journal providing information about
the authors, including their qualifications. We, as readers, seek
information on the authors' educational background and professional
experience (using their qualifications as a proxy), and also previous
publications. We do this in order to understand their perspective, and
to help us put their interpretations of results into context. This
information is perhaps most important when the writing involves opinion
and speculation, which includes the discussion of results. In any event,
in the age of Internet search engines, the qualifications and background
of many authors are not hidden.
On another point, we do not begrudge the trolley boy's scholarly
aspirations. We agree with the Editors that he may be well-positioned to
write about his first-hand observations in the hospital. As readers, we
would prefer to know when it was the trolley boy's work, in order to
understand his perspective and the context of his writing. We may have
interpreted the same article differently had it been written by the
professor of infectious diseases, the senior lecturer in surgery, or the
newly graduated trainee in dermatology.
Finally, we commend Ivan Schwab for his fascinating BJO articles. We warmly
welcome him to our country, and we hope he enjoys studying our fauna.
Dear Editor
We read with interest the paper by Tan et al. [1] on Charles Bonnet Syndrome (CBS) in Asian patients. Their finding of a lower CBS prevalence than European or North American surveys demands further investigation, although this may reflect the stringent criteria of hallucination complexity they used in making the diagnosis (thus excluding the commonest CBS hallucinations of coloured blobs and gri...
Dear Editor
The paper by Munkvitz et al. deals with the interpretation of the Nerve Fiber Analyzer (NFA) printout in a sample of healthy and advanced or early glaucomatous eyes. Three independent readers, at different levels of clinical experience, classified GDx printouts while being masked with respect to the eye condition and optic disc pictures. A questionnaire was used by readers to determine diagnosis but n...
Dear Editor
Developmental mosaicism in the eye may follow the “lines of Blaschko” Ruggieri M et al. nicely described the ophthalmological manifestations in segmental neurofibromatosis type 1 [1]. They postulated that segmental NF1 is a somatic mosaicism for the NF1-gene expressing two different embryological tissues in the eye.
Previously we described a patient with unilateral sectorial hyperpigmented ski...
Dear Editor
We thank Dr Masood for his interest in our manuscript [1]. Clearly in some cases of giant cell arteritis (GCA), treatment with high dose corticosteroids alone is insufficient. The use of adjunctive heparin proved to be beneficial in our patient, although the reason is not clear [1]. Thrombocytosis has been shown to occur in a large percentage of patients with GCA [2, 3]. However, there is no convin...
Dear Editor
We thank Drs. Kymes and Frick for their excellent letter regarding utility analysis as a health-related quality of life instrument. We agree that the use of primarily function-based quality of life instruments such as the NEI-VFQ-25 may result in missing many important variables in the quality of life arena, as well as limit applicability across all diseases.1 In contrast, preference-based quality of...
Dear Editor
We read with interest the article by Ebner et al [1] investigating the efficacy of periocular triamcinolone for the treatment of Thyroid Associated Ophthalmopathy (TAO) and the presence of ocular or systemic adverse effects also previously published in 2001 [2]. The study used patients with TAO of less than 6 months duration previously untre...
Dear Editor,
We appreciate the comments of Sridhar et al. regarding our letter: “The role of corticosteroids in fungal keratitis: a different view” published in your journal [1]. The authors comment on our recommendation for a gradual tapering of corticosteroids in cases where steroids were used for the treatment of initially misdiagnosed fungal corneal infections.
As mentioned in our cases rep...
Dear Editor
We read the interesting article by L Wickham and associates, “Vitrectomy and gas for inferior break retinal detachments: are the results comparable to vitrectomy, gas and scleral buckle?” [1]. They have compared the results of vitrectomy and gas without scleral buckle (Group A) with, vitrectomy and gas with scleral buckle (Group B) for inferior break retinal detachments. We would like to point out to a...
Dear Editor
In a fine recent editorial, Drs. Melissa and Gary Brown raised issues at the nexus of health policy and clinical science [1]. As utility assessment is relatively new to the visual sciences, understanding both the assumptions behind this work and the consequences of relaxing those assumptions is essential for high quality research and appropriate interpretation of the results.
The use of com...
Dear Editor
We thank the BJO for publishing our Letter to the Editor regarding appending authors' qualifications [1] and for inviting correspondence from its readership on the issue in the editorial "Who is Ivan Schwab?"[2].
The editors wisely remind us that medical authorities have suppressed important findings by lesser-known authors, using the notable example of Semmelweis. Even today, critical new info...
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