We thank Dr Kesarwani for the interest in our article.
In response to the points raised:
1. Inclusion criteria
We attempted to recruit children with X(T) measuring more than 20 prism
dioptres when fixing a 6 metre target, as angles under this amount are
usually felt not to require treatment. However, Dr Kesarwani is correct to
point out that, at the baseline assessme...
We thank Dr Kesarwani for the interest in our article.
In response to the points raised:
1. Inclusion criteria
We attempted to recruit children with X(T) measuring more than 20 prism
dioptres when fixing a 6 metre target, as angles under this amount are
usually felt not to require treatment. However, Dr Kesarwani is correct to
point out that, at the baseline assessment following recruitment to the
study, some children had angles of strabismus measuring < 20 pd. We
were interested to see how the score performed in children with small
angle X(T) and so decided not to exclude them.
2. Stereoacuity values
The reason the distance stereoacuity mean is lower than the near is
probably due to the range of stereoacuities each test provides. For
values of less than 200" for distance
the score will be negative as this is the largest disparity possible (if
tested at 3m) however, one can test up to (down to) a disparity of 600" on
the FNS.
3. Median distance stereoacuity values included values calculated
with adjustment for interpupillary distance.
Once again, we thank Dr Kesarwani for attentive reading of our paper
The published study by Conart and colleagues is described as a nested case-control study; however, this is incorrect.1 Participants were selected based on the presence or absence of high myopia and were matched with respect to time of surgery, duration of symptoms, and preoperative visual acuity. The participants were followed up prospectively to compare anatomical and functional outcomes following epiretinal membrane (ERM) surg...
The published study by Conart and colleagues is described as a nested case-control study; however, this is incorrect.1 Participants were selected based on the presence or absence of high myopia and were matched with respect to time of surgery, duration of symptoms, and preoperative visual acuity. The participants were followed up prospectively to compare anatomical and functional outcomes following epiretinal membrane (ERM) surgery among patients with and without high myopia. This describes a matched cohort study, not a nested case-control study. This error has implications for the appropriate statistical analysis, and therefore, the proper interpretation of the observed results. In addition, the statistical tests employed do not account for the matched nature of the study design and therefore are not appropriate. Statistical procedures that account for the matched nature of the study should have been employed. Furthermore, the authors also compared the mean change in best corrected visual acuity and central macular thickness from baseline to 1-year post-surgery within each exposure group (in the text, pages 3-4); however, none of the statistical tests used accounted for the within-person correlation that occurs when taking multiple measurements from the same subject. Specifically, the authors used Student's t-test when paired t-tests should have been used. Authors are strongly encouraged to conduct a reanalysis of their study data using statistical procedures suitable for this study design and provide readers with the appropriate p-values, amending their interpretation as warranted.
References
1. Conart J-B, Favel C, Selton J, et al. Outcomes of epiretinal membrane surgery in highly myopic eyes: a case-control study. Br J Ophthalmol. 2014.
Thank you for your comments. Two cases with the exfoliation syndrome
and one with pigmentary glaucoma were included in our study. As you
mentioned, dilatation of the pupil often causes a rise of intraocular
pressure in such cases. However, none of the three individuals in our
study had a significant rise of intraocular pressure or progression of
glaucoma.
Sincerely,
George Sp...
Thank you for your comments. Two cases with the exfoliation syndrome
and one with pigmentary glaucoma were included in our study. As you
mentioned, dilatation of the pupil often causes a rise of intraocular
pressure in such cases. However, none of the three individuals in our
study had a significant rise of intraocular pressure or progression of
glaucoma.
Sincerely,
George Spaeth M.D.
Dear Editor;
We have read the article entitled "Comparison of Umbilical Cord Serum and
Amniotic Membrane Transplantation in Acute Ocular Chemical Burns" by
Sharma et al. with interest.1 The authors compared the efficacy of
amniotic membrane transplantation (AMT) and umbilical cord serum (UCS) in
patients with ocular chemical burns. They found that UCS treatment was
superior to AMT in maintaining a better ocular surface....
Dear Editor;
We have read the article entitled "Comparison of Umbilical Cord Serum and
Amniotic Membrane Transplantation in Acute Ocular Chemical Burns" by
Sharma et al. with interest.1 The authors compared the efficacy of
amniotic membrane transplantation (AMT) and umbilical cord serum (UCS) in
patients with ocular chemical burns. They found that UCS treatment was
superior to AMT in maintaining a better ocular surface. The authors also
emphasized that UCS treatment offers the benefit of avoiding a surgical
maneuver in already inflamed eyes.
Human tear film contain multiple biologically active growth factors and
essential components secreted by the lacrimal gland. These substances
include transforming growth factor-?, basic fibroblast growth factor,
epidermal growth factor, neurotrophic factors and vitamin A. These
componenets play critical roles in maintaining the health of ocular
surface structures.2 It has been revealed that UCS includes many
neurotrophic factors, essential tear components and growth factors. It is
a more valuable adjunct than autologous serum in the management of
persistent epithelial defects and severe dry eye syndrome.3 In addition to
these biological effects, it acts as a lubricant due to physical
characteristics similar to tears. We assume that the superiority of UCS to
AMT may be attributed to those features mentioned above.
A recent study showed that amniotic membrane is able to remove reactive
oxygen species due to the presence of abundant hyaluronic acid.4 That
property may be advantageous in distinct clinical entities in which
oxidative stress is involved in the pathogenesis. For example; the role of
oxidative stress in mustard-induced chemical injury is well-defined.
Therefore; AMT may be preferred to UCS in the treatment of chemical ocular
surface burns especially in the acute phase.
REFERENCES:
1. Sharma N, Lathi SS, Sehra SV, et al. Comparison of umbilical cord
serum and amniotic membrane transplantation in acute ocular chemical
burns. Br J Ophthalmol. 2014;
2. Klenkler B, Sheardown H, Jones L. Growth factors in the tear film: role
in tissue maintenance, wound healing, and ocular pathology. Ocul Surf.
2007; 5:228-239.
3. Yoon KC, Im SK, Park YG, et al. Application of umbilical cord serum
eyedrops for the treatment of dry eye syndrome. Cornea. 2006; 25:268-272.
4. Lockington D, Agarwal P, Young D, et al. Antioxidant properties of
amniotic membrane: novel observations from a pilot study. Can J
Ophthalmol. 2014; 49:426-430.
Epigenetic regulation of tumor suppressor genes provides an
attractive mechanism for tumors in which mutations and structural changes
are rare. The latter may apply to uveal melanoma for which little is known
of the genes that contribute to tumor development. In the search for
genes, uveal melanoma is often compared to its counterpart in the skin,
cutaneous melanoma. One of the major cuteneous melan...
Epigenetic regulation of tumor suppressor genes provides an
attractive mechanism for tumors in which mutations and structural changes
are rare. The latter may apply to uveal melanoma for which little is known
of the genes that contribute to tumor development. In the search for
genes, uveal melanoma is often compared to its counterpart in the skin,
cutaneous melanoma. One of the major cuteneous melanoma genes is the p16
encoding CDKN2A gene for which mutations and deletions are the major
mechanisms of inactivation. Deletions and mutations in CDKN2A are however
rare in uveal melanoma; still p16 expression is lacking in half of the
cell lines[1]. Using methylation analysis and methylation inhibition in cell
culture, we have shown that the underlying mechanism of loss of p16
expression in these cell lines is methylation of CDKN2A. This observation
is not disputed but controversy arises when primary tumors are analyzed
and estimates are given for the extend of CDKN2A methylation in uveal
melanoma[2,3]. The study by Moulin et al is an example of a study that
displays some remarkable deviations from results we and others have
achieved previously[4,5]. We would like to comment on some of the technical
and biological factors that may contribute to the lack of consistency in
the results that are achieved in the field of uveal melanoma epigenetics.
The molecular mechanism of epigenetic gene regulation is complex and
characterized by multiple molecular events that are functionally
connected. Hence, the analysis of only one of these events will never be
sufficient to fully explain the downregulation of tumor suppressor genes.
Whereas tumor cell lines probably present the endpoint of epigenetic
silencing and commonly display a homogeneous methylation profile, primary
tumors in contrast frequently present a more heterogeneous pattern of
methylation. We presume that this heterogeneity is correlated with the
progress of epigenetic silencing. On the one hand it is possible that
only a fraction of the tumor cells carries methylated tumor suppressor
genes, on the other hand the degree of CpG methylation may vary over a
broad range, depending on the advance of the epigenetic silencing. Despite
this heterogeneity, methylation can be used as molecular marker and may
have an important role in the pathogenesis of uveal melanoma.
The heterogeneity of the methylation requires sensitive techniques to
reveal this methylation in primary tumors. With the advent of bisulfite
modification of DNA, the analysis of methylation has increased enormously.
Most commonly applied techniques are the methylation-specific PCR (MSP)
and bisulfite sequence analysis. MSP is a technique with a high
sensitivity that is based on PCR primers that are specific for methylated
and unmethylated DNA. A drawback of this method is the false positive rate
due to illegitimate polymerization of methylation-specific primers that
are hybridized to unmethylated DNA which is a common event due to the
error rate of the polymerase. Therefore, we propose that MSP requires
validation by an additional technique. Initially we have used restriction
enzyme analysis for validation of internal CpG’s [1]. Recently, we turned to
melting temperature analysis of bisulfite PCR reactions that amplify both
methylated and unmethylated DNA. Analysis of these PCR reactions provides
insight into the degree of methylation and the quantity of methylated and
unmethylated fractions in tumor tissue[6]. Reanalysis of primary uveal
melanoma with melting point analysis for CDKN2A (previously analyzed with
MSP) indicated that the methylated fraction rarely exceeded 10% of the
tumor DNA (unpublished). Because of this low percentage, most of the
tumors will not test positive with the assay used by Moulin et al.
Loss of p16 expression is observed in many tumors and marks a
critical event in tumor development. Epigenetic silencing of the CDKN2A
gene (or any other tumor suppressor gene of interest) in uveal melanoma
should therefore be recognized even if it is only present in a minority of
cells as it may represent the malignant component of the tumor.
References
1. van der Velden,P.A. et al. Promoter Hypermethylation: A Common
Cause of Reduced p16(INK4a) Expression in Uveal Melanoma. Cancer Res 61,
5303-5306 (2001).
2. Lamperska,K. et al. Expression of p16 in sporadic primary uveal
melanoma. Acta Biochim. Pol. 49, 377-385 (2002).
3. Edmunds,S.C., Kelsell,D.P., Hungerford,J.L. & Cree,I.A.
Mutational analysis of selected genes in the TGFbeta, Wnt, pRb, and p53
pathways in primary uveal melanoma. Invest Ophthalmol. Vis. Sci. 43, 2845-
2851 (2002).
4. Merhavi,E. et al. Promoter methylation status of multiple genes
in uveal melanoma. Invest Ophthalmol. Vis. Sci. 48, 4403-4406 (2007).
5. Moulin,A.P., Clement,G., Bosman,F.T., Zografos,L. &
Benhattar,J. Methylation of CpG island promoters in uveal melanoma. Br. J.
Ophthalmol. 92, 281-285 (2008).
6. Maat,W. et al. Epigenetic Inactivation of RASSF1a in Uveal
Melanoma. Invest Ophthalmol. Vis. Sci. 48, 486-490 (2007).
Kashkouli and colleagues (1) have studied a subject with high
clinical relevance. Meibomian gland dysfunction is prevalent and treatment
often unsatisfactory. Oral azithromycin has advantages over oral
doxycycline including dosing and side effects as reviewed in the article.
There are a few problems with the methods to be highlighted so that
readers can draw accurate conclusions, and validation studies be
constr...
Kashkouli and colleagues (1) have studied a subject with high
clinical relevance. Meibomian gland dysfunction is prevalent and treatment
often unsatisfactory. Oral azithromycin has advantages over oral
doxycycline including dosing and side effects as reviewed in the article.
There are a few problems with the methods to be highlighted so that
readers can draw accurate conclusions, and validation studies be
constructed appropriately. This is done in point form below.
-Statement of a null hypothesis a priori would have been helpful to
interpret the trial as a non-inferiority or superiority design. (2)
-The sample size calculation was designed "to detect at least 1.8
differences". It is not clear why this number was chosen and cannot be
gleaned from the cited articles. Was the trial adequately powered to meet
the aims of assessing efficacy and safety?
-Ideally, a new scale as used in the study should be validated before
use in a trial.
-Ten patients were lost to follow-up. Their baseline characteristics
should be reported and compared to those who completed follow-up. (3)
Intention-to-treat analysis can determine the maximum effect on the
results of those lost to follow-up by assuming the extremes of outcome and
recalculating. (4) The null hypothesis is important to assign the extremes
appropriately.
-"Symptoms significantly improved in both groups (p=0.001, 95%CI -2.2
to -0.7)". A similar statement exists for clinical signs. There are two
groups and there should be a 95%CI for each. It cannot be determined to
which group these values correspond.
-The Bonferroni multiple comparisons test applies to the data shared
in Table 4. With seven variables, the p value for significance is 0.007
(0.05/7). Therefore, ocular surface staining is no longer significant in
this conservative model.
The potential impact of repeated dosing of oral azithromycin on
bacterial resistance was not addressed in the discussion and also deserves
comment from the authors.
In light of these concerns, conclusions from this study should be
tempered until the results are validated.
1. Kashkouli MB, Fazel AJ, Kiavash V, Nojomi M, Ghiasian L. Oral
azithromycin versus doxycycline in meibomian gland dysfunction: a
randomized double masked open label clinical trial. Br J Ophthalmol ePub
19 Aug 2014.
2. Committee for Proprietary Medicinal Products. Points to consider
on switching between superiority and non-inferiority. Br J Clin Pharmacol
2001; 52:223-228.
3. Groenwold RHH, Moons KGM, Vandenbroucke JP. Randomized trials with
missing outcome data: how to analyze and what to report. CMAJ 2014;
186:1153-1157.
4. Guyatt GH, Sackett DL, Cook DJ. Users' guides to the medical
literature. II. How to use an article about therapy or prevention. A. Are
the results of the study valid? Evidence-Based Medicine Working Group.
JAMA 1993; 270:2598-2601.
We thank Dr Ayata for the thoughtful comments of our article. He
had three questions that we would like to answer as follows:
1) Figure 1 was quite important for the paper because it shows the
exact
location of the macular pigment in monkeys (courtesy of Francois Delori,
PhD). We are sorry for the lack of the image in the on-line paper
version but it was probably due to the PDF saving...
We thank Dr Ayata for the thoughtful comments of our article. He
had three questions that we would like to answer as follows:
1) Figure 1 was quite important for the paper because it shows the
exact
location of the macular pigment in monkeys (courtesy of Francois Delori,
PhD). We are sorry for the lack of the image in the on-line paper
version but it was probably due to the PDF saving process.
2) We do not think there is any inconsistency between results and
conclusion because that was exactly what we expected. If a pseudohole is
a macular lesion where there is no loss of foveal tissue, the presence
of foveal AF indicates the absence of macular pigment in the fovea.
Being the pigment located in the outer plexiform layer and outer nuclear
layer in the fovea (fig 1), that means we were dealing with lamellar
rather than pseudo macular holes. Our paper just underlined the finding
that OCT alone is inadequate to differentiate pseudo from lamellar
holes. As to this respect AF imaging may be useful because reveals a
loss of foveal tissue.
3) We are aware of the different aspects of AF-imaging after dark
and
light adaptation. As Dr Ayata properly pointed out, the visible changes
in AF imaging in light and dark adapted eyes are minimal in the fovea
and the lack of macular pigment in lamellar macular hole is in the
fovea. The AF ratio was used to correlate AF intensities with residual
retinal thickness at the bottom of the defect. The reason why we did not
use raw images for AF quantitative measurements was related to the great
difficulties in visualizing foveal defect in non normalized images. The
ratio could have affected the results of these correlations but not the
presence of foveal AF itself.
We thank again Dr Ayata for his interest in our article.
Dear sir,
We read the article by Abdulhalim et al with great interest (1) . The article remind us that both CONJUNCTIVAL FLAP and AMNIOTIC MEMBRANE GRAFT are effective in corneal healing and can be an alternative to keratoplasty in cases of infectious keratitis. However we have some concerns: The way to assess the mean size of ulcer and depth and the healing time in the post operative period would have made the comparis...
Dear sir,
We read the article by Abdulhalim et al with great interest (1) . The article remind us that both CONJUNCTIVAL FLAP and AMNIOTIC MEMBRANE GRAFT are effective in corneal healing and can be an alternative to keratoplasty in cases of infectious keratitis. However we have some concerns: The way to assess the mean size of ulcer and depth and the healing time in the post operative period would have made the comparison more interesting. The outcome of both these procedures if compared with keratoplasty -which is the gold standard in treatment of recalcitrant ulcer would have given us an information regarding which ulcers will benefit from these two procedures.(2) If proved that they are equally effective or superior to keratoplasty then we can save some corneas which can be used for optical purposes in other patient. Patient will be free from post keratoplasty frequent follow up and long term steroid application.
Since the study was started in 2011 and finished in 2012, there might have been patients who were amenable for keratoplasy for visual rehabilitation. Such an outcome would be interesting to look at and could have established both these procedures for treatment of recalcitrant ulcers.
However this article has encouraged us to start these old but highly effective methods in our institution. We can leave a small band of conjunctiva while doing peritomy so that limbal stem cells remain undisturbed. We are thankful to author for such valuable information.
CONFLICT OF INTEREST
The authors have no conflict of interests disclose
FUNDING SOURCE
The authors have no funding source to disclose
References-
1) Amniotic membrane graft to conjunctival flap in treatment of non-viral resistant infectious keratitis:
a randomised clinical study Bahaa-Eldin Hasan Abdulhalim,1 Mostafa Mohamed Wagih,1 Ahmed A M Gad,1 Ghada Boghdadi,2 Ragy R S Nagy3 ,BJO , July 22, 2014
2) J Kanski and B Bowling , Clinical Ophthalmology - A systematic approach( 7th ed), 240-244.
Debasmita Majhi, Srikant Kumar Sahu (srikant@lvpei.org;
Srikant_sahu1@yahoo.co.in), Danish Alam,
L V Prasad eye institute, Bhubaneswar, India
Correspondence: Srikant Kumar Sahu, MS, cornea and anterior segment services, L V Prasad Eye Institute, Bhubaneswar
751024, India.
Tel: 91-9439488888
Emails: srikant@lvpei.org;
Srikant_sahu1@yahoo.co.in)
A metastizing adenocarcinoma of the retinal pigment epithelium in a 37-year-old man with Down syndrome (DS) has recently been reported in the
British Journal of Ophthalmology [1]. In the article the authors underlined
an unusual and atypical aggressive behaviour of the tumour which was the
first well documented adenocarcinoma of the retinal pigment epithelium
with metastases. Although solid tumours are...
A metastizing adenocarcinoma of the retinal pigment epithelium in a 37-year-old man with Down syndrome (DS) has recently been reported in the
British Journal of Ophthalmology [1]. In the article the authors underlined
an unusual and atypical aggressive behaviour of the tumour which was the
first well documented adenocarcinoma of the retinal pigment epithelium
with metastases. Although solid tumours are globally less frequent in
persons with DS than in the general population [2] this does not seem to
apply to ocular neoplasms. Including Heindl's et al report 30 cases of
primary or secondary malignant tumours of the eye and orbit have been
reported so far, two thirds being retinoblastoma [3]. Unfortunately, but
interestingly, some neoplasms in patients with DS may have a rapid
progression as observed in a low grade glioma [4]. The reason for this
unfavourable course in some patients remains unknown. Nonetheless, as
ocular malignant neoplasm could be more frequent in children and adults
with DS, and since some of these tumours may have an unexpected aggressive
behaviour, we want to attract attention on them to allow a precocious
diagnosis and early treatment.
The study on tumors in DS is supported by the Fondation Jérôme
Lejeune.
References
1. Heindl LM, Naumann GO, Kruse FE, Holbach LM. Aggressive
metastasising adenocarcinoma of the retinal pigment epithelium with
trisomy 21. Br J Ophthalmol. 2008;92:389-91
2. Patja K, Pukkala E, Sund R, Iivanainen M, Kaski M. Cancer
incidence of persons with Down syndrome in Finland: a population-based
study. Int J Cancer. 2006;118:1769-72
3. Satgé D, Lacombe D, Vekemans M, Bonnet A, Réthoré M-O, Munier F. A
survey of ocular tumors in Down syndrome alone or associated with another
genetic affection. Int J Disabil Human Dev 2006;5:311-7
4. Satgé D, Monteil P, Sasco AJ, Vital A, Ohgaki H, Geneix A, Malet
P, Vekemans M, Réthoré MO. Aspects of intracranial and spinal tumors in
patients with Down syndrome and report of a rapidly progressing Grade 2
astrocytoma. Cancer. 2001;91:1458-66
Previously, I reported that head tilting during optical coherence
tomography (OCT) image acquisition affects circumpapillary retinal nerve
fibre layer (RNFL) and macular retinal thickness measurement.1 Although
the subject's head and chin are appropriately positioned, a possibility of
inter-test variation in head alignment still exists. A useful strategy to
overcome this limitation is tracking the subsequent image to the...
Previously, I reported that head tilting during optical coherence
tomography (OCT) image acquisition affects circumpapillary retinal nerve
fibre layer (RNFL) and macular retinal thickness measurement.1 Although
the subject's head and chin are appropriately positioned, a possibility of
inter-test variation in head alignment still exists. A useful strategy to
overcome this limitation is tracking the subsequent image to the prior
image. Recently, Cirrus high-definition (HD) OCT (Carl Zeiss Meditec,
Dublin, California, USA) introduced an eye-tracking system (FastTracTM
retinal tracking system), which was developed to reduce the artifacts
induced by eye movement during scan acquisition and to allow image capture
at identical points during each visit. Till date, it is yet to be
determined whether the retinal tracking system can reduce artifacts
induced by head tilting during OCT examination.
To test this hypothesis, 10 eyes from 5 healthy young subjects
without ocular and neurologic disorders were recruited. RNFL thickness was
measured at a baseline head position without head tilting and at the right
and left head tilt positions as described previously.1 Differences in
thicknesses and peak locations of RNFL between the baseline head position
and head tilt positions were analysed using Wilcoxon signed rank test.
When the retinal tracking system was not used, right and left head tilt
induced significant changes in thicknesses and peak locations of RNFL.
However, when the retinal tracking system was used, none of the RNFL
parameters showed significant change during head tilting. This result
suggests that the Cirrus HD-OCT retinal tracking system can reduce inter-
test variation induced by head tilting during OCT image acquisition. To
identify the range of head tilt degree in which the retinal tracking
system can operate and its utility in patients with cyclotorsional eye
movement disorders, further studies are needed.
Reference
1. Hwang YH, Lee JY, Kim YY. The effect of head tilt on the measurements
of retinal nerve fibre layer and macular thickness by spectral-domain
optical coherence tomography. Br J Ophthalmol 2011;95:1547-51.
Dear Editor
We thank Dr Kesarwani for the interest in our article.
In response to the points raised:
1. Inclusion criteria
We attempted to recruit children with X(T) measuring more than 20 prism dioptres when fixing a 6 metre target, as angles under this amount are usually felt not to require treatment. However, Dr Kesarwani is correct to point out that, at the baseline assessme...
Dear Dr Radcliffe and colleagues,
Thank you for your comments. Two cases with the exfoliation syndrome and one with pigmentary glaucoma were included in our study. As you mentioned, dilatation of the pupil often causes a rise of intraocular pressure in such cases. However, none of the three individuals in our study had a significant rise of intraocular pressure or progression of glaucoma. Sincerely, George Sp...
Dear Editor; We have read the article entitled "Comparison of Umbilical Cord Serum and Amniotic Membrane Transplantation in Acute Ocular Chemical Burns" by Sharma et al. with interest.1 The authors compared the efficacy of amniotic membrane transplantation (AMT) and umbilical cord serum (UCS) in patients with ocular chemical burns. They found that UCS treatment was superior to AMT in maintaining a better ocular surface....
Dear editor,
Epigenetic regulation of tumor suppressor genes provides an attractive mechanism for tumors in which mutations and structural changes are rare. The latter may apply to uveal melanoma for which little is known of the genes that contribute to tumor development. In the search for genes, uveal melanoma is often compared to its counterpart in the skin, cutaneous melanoma. One of the major cuteneous melan...
Kashkouli and colleagues (1) have studied a subject with high clinical relevance. Meibomian gland dysfunction is prevalent and treatment often unsatisfactory. Oral azithromycin has advantages over oral doxycycline including dosing and side effects as reviewed in the article.
There are a few problems with the methods to be highlighted so that readers can draw accurate conclusions, and validation studies be constr...
Dear Editor
We thank Dr Ayata for the thoughtful comments of our article. He had three questions that we would like to answer as follows:
1) Figure 1 was quite important for the paper because it shows the exact location of the macular pigment in monkeys (courtesy of Francois Delori, PhD). We are sorry for the lack of the image in the on-line paper version but it was probably due to the PDF saving...
Dear Editor
A metastizing adenocarcinoma of the retinal pigment epithelium in a 37-year-old man with Down syndrome (DS) has recently been reported in the British Journal of Ophthalmology [1]. In the article the authors underlined an unusual and atypical aggressive behaviour of the tumour which was the first well documented adenocarcinoma of the retinal pigment epithelium with metastases. Although solid tumours are...
Previously, I reported that head tilting during optical coherence tomography (OCT) image acquisition affects circumpapillary retinal nerve fibre layer (RNFL) and macular retinal thickness measurement.1 Although the subject's head and chin are appropriately positioned, a possibility of inter-test variation in head alignment still exists. A useful strategy to overcome this limitation is tracking the subsequent image to the...
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