The rising use of Avastin injection for choroidal neovascular membranes
and other conditions has been successful in preliminary reports.
However, I have experienced 5 cases with optic neuropathy following
Avastin
injection after an interval of 2-4 months. Although my number of cases
is
very small, it suggests that a study be conducted to investigate the
effect of intravitreal Avastin on the optic nerve u...
The rising use of Avastin injection for choroidal neovascular membranes
and other conditions has been successful in preliminary reports.
However, I have experienced 5 cases with optic neuropathy following
Avastin
injection after an interval of 2-4 months. Although my number of cases
is
very small, it suggests that a study be conducted to investigate the
effect of intravitreal Avastin on the optic nerve using VEP.
Prof Dr Sherif Ahmed Kamel Amer
MBBCh, MSc ophthalmology, MD ophthalmology, Cairo University, ICO.Ophth.
Fellow of The Ophthalmology Department, Cairo University Hospitals (Kasr
Al Aini).
Supervisor of The Neuro-Ophthalmology Clinic
National Eye Center (Rod El Farag).
Ass Professor of Ophthalmology Beni Suif University, Egypt
I wish to thank Ganesh et al for confirming (p <0.001) the marked
and obvious difference between the age distribution of retinal and
subdural haemorrhages in America and Japan. Finding this difference "not
surprising" neither negates nor explains it. More sophisticated child
abuse teams could not discover cases in Japan months before they occur.
Variations in incidence of osteogenesis imperfecta wou...
I wish to thank Ganesh et al for confirming (p <0.001) the marked
and obvious difference between the age distribution of retinal and
subdural haemorrhages in America and Japan. Finding this difference "not
surprising" neither negates nor explains it. More sophisticated child
abuse teams could not discover cases in Japan months before they occur.
Variations in incidence of osteogenesis imperfecta would not either. While
in America apparently people "lose it" and shake kids 4-6 weeks after they
cry (the "lag time" between the crying and SBS incidence curves), it is
unlikely the Japanese wait several months more. The traditional
explanations of differences in relative head size and strength of neck
muscles and vitreo-retinal adherence also fail to explain it. Thus, my
suggestion of an inquiry into this difference remains unaddressed.
The authors would like to thank Dr. J.J. Wang for her constructive
comments about the statistical analysis of the data obtained in the
Beijing Eye Study.[1] As already pointed out in another recent reply to a
letter by Dr. Wang, the authors became aware of the limitations in their
statistical analysis of the data of the Beijing Eye Study.[2] The authors
are grateful to Dr. Wang for clarifying these wea...
The authors would like to thank Dr. J.J. Wang for her constructive
comments about the statistical analysis of the data obtained in the
Beijing Eye Study.[1] As already pointed out in another recent reply to a
letter by Dr. Wang, the authors became aware of the limitations in their
statistical analysis of the data of the Beijing Eye Study.[2] The authors
are grateful to Dr. Wang for clarifying these weaknesses so that these
weaknesses may be avoided in future statistical analyses of the data of
the Beijing Eye Study. In the article on the associated factors for age-related maculopathy in the adult population in China,[1] the figures in
the brackets of the Table generally give the 95% confidence intervals of
the odds ratios. The use of the abbreviation ”ARD” for “age-related
maculopathy” was a typographical error, instead of using “ARM” as
explained in the first paragraph of the Abstract. The association
estimates presented in the Table are crude (unadjusted).
Although Dr. Wang´s letter is rather critical about the statistical
analysis of the Beijing Eye Study, the authors are grateful to her for
showing up limitations in the statistical analysis, weaknesses that may be
avoided in future statistical analyses of the data of the Beijing Eye
Study.
References
1. Xu L, Li Y, Zheng Y, Jonas JB. Associated factors for age-related
maculopathy in the adult population in China. The Beijing Eye Study. Br J
Ophthalmol 2006; 90:1087-90.
2. Jonas JB, Xu L. Reply to the Letter-to-the-Editor, written by Wang JJ,
concerning the Beijing Eye Study. Am J Ophthalmol 2007; In Press.
I read with interest the report from the Beijing Eye Study by Xu, et al. published in BJO last year (BJO 2006;90:1087-1090), titled:
Associated
factors for age related maculopathy in the adult population in China:
the
Beijing Eye Study.
In the abstract, Results and Table 1 of this report, some
association
estimates are provided as p values and 95% confidence intervals without
point estimate...
I read with interest the report from the Beijing Eye Study by Xu, et al. published in BJO last year (BJO 2006;90:1087-1090), titled:
Associated
factors for age related maculopathy in the adult population in China:
the
Beijing Eye Study.
In the abstract, Results and Table 1 of this report, some
association
estimates are provided as p values and 95% confidence intervals without
point estimates for the likelihood (such as the associations with age,
refractive error, education and rural area), others are provided as p
values, odds ratios (OR) and 95% confidence intervals (such as the
associations with systemic and ocular diseases). For the association
between posterior subcapsular cataract and late ARM, only a p value is
provided. It is very confusing to the reader to determine what these 95%
confidence intervals are for: are they for the p values, or the odds
ratios? Does this depend on what they follow? It is also unclear to the
reader why the authors describe their data in such an inconsistent way.
By reading the Table alone, I could not find information about
whether the association estimates are crude (unadjusted) or had been
adjusted for other co-variables, and if they are adjusted, what the co-variables are.
I am also surprised that during the reviewing process the reviewers
did not find this confusing way of data presentation strange, and also
did
not find the Table insufficiently self explanatory.
The authors abbreviate age-related macular degeneration as ARD but
not AMD. This is unique.
Jie Jin Wang MMed PhD
Centre for Vision Research
Department of Ophthalmology
University of Sydney
We thank Dr. Holló [1] for his comments and the opportunity to
elaborate further on our findings. We had considered the point that both
eyes from an individual may not be fully independent from one another. As
such, in our initial analysis, we calculated the Pearson’s correlation
coefficient (r) between left and right eyes for both of our measures. We
found the central corneal thickness (CCT) between...
We thank Dr. Holló [1] for his comments and the opportunity to
elaborate further on our findings. We had considered the point that both
eyes from an individual may not be fully independent from one another. As
such, in our initial analysis, we calculated the Pearson’s correlation
coefficient (r) between left and right eyes for both of our measures. We
found the central corneal thickness (CCT) between the two eyes of a same
individual to be significantly correlated with each other, r = 0.88 (p
< 0.001). However, there was no significant correlation between right
and left disc diameter (DA) r = 0.1 (p = 0.4), demonstrating reasonable
variability between left and right eye measures. Bearing this in mind,
along with the fact that our analysis examined the correlation between CCT
and DA within each eye and not across eyes, we view each CCT-DA
correlation as a separate measure.
We also took into consideration the potential for bias induced by
including two eyes from some individuals, and only one from others (a
consequence of our exclusion factors). Therefore, as a validation model,
we analyzed our data using only one random eye per subject to check for
any inconsistencies in results based on our analytical approach. The
results were consistent to those we presented in the manuscript using both
eyes [2]. Using one random eye, we found the Caucasian subgroup CCT-DA
correlation r = - 0.24 (p = 0.15), similar to the correlation r = - 0.28
in our two-eye model. We also performed a secondary analysis in the single
eye model by using a slightly relaxed exclusion criterion to allow for HRT
images with a standard deviation of less than 100 to increase the number
of subjects and hence statistical power. Again we found a matching
significant correlation r = - 0.28 (p = 0.02).
To summarize, in addition to left and right eyes demonstrating
significant variability in DA, the correlation values between CCT and DA
were reproducible in our single eye validation model and our secondary
analysis. In view of these confirmatory findings, we feel confident that
our analytic model is fitting and has not induced any significant level of
bias.
Afshin Parsa, M.D., M.P.H.
Masoumeh Sanagou, M.S.C.
Mohammad Pakravan, M.D.
Cameron F. Parsa, M.D.
References
1. Gábor Holló. Central corneal thickness and correlation to disc
size. 5 January 2007.
2. Pakravan M, Parsa A, Sanagou M, Parsa CF. Central corneal
thickness and correlation to disc size: a potential link for
susceptibility to glaucoma. Br J Ophthalmol 2007;91:26-28.
After going through the above mentioned scientific report, I have
some queries and suggestions as mentioned below:
1. Is a surgeon's opinion enough to declare a case as having
Vitreomacular traction as mentioned in this study? Or is a definite
documentation possible with aid like OCT?
2. In 2 cases, single sessions of PDT were done, which does not
match the criterion of repeated...
After going through the above mentioned scientific report, I have
some queries and suggestions as mentioned below:
1. Is a surgeon's opinion enough to declare a case as having
Vitreomacular traction as mentioned in this study? Or is a definite
documentation possible with aid like OCT?
2. In 2 cases, single sessions of PDT were done, which does not
match the criterion of repeated PDT as mentioned.
3. Number of cases were very low to come to such a conclusion.
Dr Gitumoni Sharma,
Flat 5 D, Park Apartment,
Kanaklata Path, Lachitnagar,
Guwahati, Assam,India
ZIP-781007
We read the paper titled “Anti-permeability and anti-proliferative
effects of standard and frozen bevacizumab on choroidal endothelial cells”
by Peters et al [1] in Br J Ophthalmol. Dec. 2006 issue with great interest.
There are a number of issues that we would like to point out with regards
to the methodology. The authors have solely used scratch assay in the
presence of 50ng/ml VEGF +- 0.5mg/ml b...
We read the paper titled “Anti-permeability and anti-proliferative
effects of standard and frozen bevacizumab on choroidal endothelial cells”
by Peters et al [1] in Br J Ophthalmol. Dec. 2006 issue with great interest.
There are a number of issues that we would like to point out with regards
to the methodology. The authors have solely used scratch assay in the
presence of 50ng/ml VEGF +- 0.5mg/ml bevacizumab to assess cell
proliferation. They demonstrate that when bevacizumab was added wound
closure was retarded (data presented in figures 4 and 5) and they infer
that this is because of antiproliferative effect of bevacizumab on
choroidal endothelial cells. We would like to point out that scratch assay
is an accepted method for assessing cell migration,[2-4] but it is not a
method for assessing cell proliferation. There are several limitations in
using this assay for estimating cell proliferation. If proliferating cells
fail to migrate, the wound will not close. On the other hand, the
migrating cells can close the wound without undergoing proliferation.
Therefore, based on this evidence the authors can not draw conclusions
regarding proliferation of cells. The authors have cited Roberts and
Palade [5] for the proliferation assay used in this paper. However, the cited
paper has not used any such method for assessing cell proliferation.
Additionally, in figure 5, the authors have provided microscopic evidence
for the cell proliferation assay they have used. In the micrographs
provided it appears that the cell density in bevacizumab treated sample is
much less than sample treated with VEGF alone that would add additional
bias. With regards to proliferation assay, there are excellent methods
available to do this in cell cultures.[6-8] These methods utilize
Bromodeoxyuridine, tritiated thymidine and carboxyl fluorescent
succinimidyl ester. There appears to be no apparent limitation why these
methods could not be employed, especially in a paper wherein proliferation
is a major focus.
Sincerely,
Rajesh K Sharma, M.D., Ph.D.
Kakarla V. Chalam, M.D., Ph.D.
Department of Ophthalmology
University of Florida Health Science Center
Jacksonville, FL
References
1. Peters S, Julien S, Heiduschka P et al. Anti-permeability and
anti-proliferative effects of standard and frozen bevacizumab on choroidal
endothelial cells. Br.J.Ophthalmol. 2006.
2. Johnson DA, Fields C, Fallon A et al. Polyamine-dependent
migration of retinal pigment epithelial cells. Invest Ophthalmol.Vis.Sci.
2002;43:1228-33.
3. Theisen CS, Wahl JK, III, Johnson KR et al. NHERF Links the N-
Cadherin/Catenin Complex to the PDGF Receptor to Modulate the Actin
Cytoskeleton and Regulate Cell Motility. Mol.Biol.Cell 2007.
4. Soderholm J, Heald R. Scratch n' screen for inhibitors of cell
migration. Chem.Biol. 2005;12:263-5.
5. Roberts WG, Palade GE. Increased microvascular permeability and
endothelial fenestration induced by vascular endothelial growth factor.
J.Cell Sci. 1995;108 ( Pt 6):2369-79.
6. Luzyanina T, Mrusek S, Edwards JT et al. Computational analysis
of CFSE proliferation assay. J.Math.Biol. 2007;54:57-89.
7. Nakamura T, Ang LP, Rigby H et al. The use of autologous serum in
the development of corneal and oral epithelial equivalents in patients
with Stevens-Johnson syndrome. Invest Ophthalmol.Vis.Sci. 2006;47:909-16.
8. Ye L, Haider HK, Jiang S et al. High efficiency transduction of
human VEGF165 into human skeletal myoblasts: in vitro studies.
Exp.Mol.Med. 2003;35:412-20.
We read with great interest Alwitry and coworkers' article[1] on
bilateral decompression retinopathy following medical treatment of an
acute primary angle closure. We would like to report the case of a 47
year
-old woman who consulted in November 2000 for a mildly painful
right eye. Pain had lasted for about three days.
Visual acuity was 20/20 OU with no optical correction. On slit-lamp
examination, b...
We read with great interest Alwitry and coworkers' article[1] on
bilateral decompression retinopathy following medical treatment of an
acute primary angle closure. We would like to report the case of a 47
year
-old woman who consulted in November 2000 for a mildly painful
right eye. Pain had lasted for about three days.
Visual acuity was 20/20 OU with no optical correction. On slit-lamp
examination, both corneas were clear, there was an anisocoria with a
round, non-reactive 7-mm right pupil. IOP was 38 mmHg OD and 14 mmHg OS.
Fundus examination was normal bilaterally, the 7-mm right mydriasis
allowing good visualization of peripheral retina OD. On gonioscopic
examination, angle was closed OD. The patient was treated topically with
timolol 0.50 bid, dorzolamide tid, pilocarpine 2% tid. Three days later,
visual acuity was still 20/20 OU. IOP had dropped to 15 mmHg OD. There
was
a reactive semi-mydriasis OD. Gonioscopy showed a Sheie III (bottom
part)/
Sheie IV (top part) angle OD. Indentation gonioscopy disclosed a plateau
iris configuration OD, the central iris being pushed back with no
further
elements disclosure. Fundus examination showed scattered blot-shaped
retinal haemorrhages with one larger white-centred (probable fibrin
plug)
temporal haemorrhage (figure 1). A week later the patient had a laser
iridotomy OD. All haemorrhages had cleared. Two weeks later, the patient
took no medication. At that time, a patent right iridotomy, a right
reactive semi-mydriasis with an IOP of 30 mmHg OD and a closed angle OD
were noted. The patient was diagnosed with a plateau iris syndrome OD.
IOP
was controlled with pilocarpine 2% bid OD.
In this case as in Alwitry and coworkers'(1), decompression retinopathy
occurred following exclusive medical treatment of acute primary angle
closure. It is remarkable that in our case IOP elevation was relatively
mild and IOP drop after treatment was only 23 mmHg. One may wonder
whether
or not the plateau iris syndrome played a role in the occurrence of
decompression retinopathy in our patient. The case we report featured
mild
decompression retinopathy and, as previously reported, outcome was
excellent.
Figure 1
Right fundus showing blot-shaped scattered haemorrhages sparring the
foveola with one larger white-centred temporal haemorrhage
References
1 Alwitry A, Khan K, Rotchford A, Zaman AG, Vernon SA. Severe
decompression retinopathy following medical treatment of acute primary
angle closure. Br J Ophthalmol 2007;91:121
I am in strong agreement with Waddell that the treatment of
conjunctival neoplasia in Africa should primarily be surgical excision
and not medical drugs.
As an ophthalmologist working in Malawi-Southern Africa where the
prevalence of HIV is very high (8.3% of whole population), conjuctival
tumours have become the dominant condition requiring surgery. In 2006
alone
a total of 467 cases of advanced con...
I am in strong agreement with Waddell that the treatment of
conjunctival neoplasia in Africa should primarily be surgical excision
and not medical drugs.
As an ophthalmologist working in Malawi-Southern Africa where the
prevalence of HIV is very high (8.3% of whole population), conjuctival
tumours have become the dominant condition requiring surgery. In 2006
alone
a total of 467 cases of advanced conjuctival neoplasia underwent
surgery (430 had surgical excisions; 37 had either enucleation or
exenteration done) at Lions Sight First Eye Hospital in Blantyre. This
represents 26% of all surgeries done at this hospital in 2006.
Conjuctival
tumours were the most frequent conditions requiring admissions out of
all
the out-patients seen. We do not advocate medical treatment as it would
be
very costly in our set-up; followup of patients is difficult and most
of
the cases that we see are already at an advanced stage at presentation
and
would not respond to medical therapy alone. The suggestion by authors
to do further larger studies of this condition can easily be done at our
hospital where at least 3-5 outpatient cases of conjuctival carcinoma
are
seen on a daily basis. We would be more than willing to assist anyone
interested in doing such studies at our eye hospital.
We read with great interest the study published by Srinivasan et al [1]. It sheds light over the primary management of an endemic problem,
corneal ulceration, at the village level. We have a few comments to make.
The study suggests that there is no statistically significant
difference in the rates of fungal corneal ulceration in patients with
corneal abrasions with antifungal prophylaxis or wi...
We read with great interest the study published by Srinivasan et al [1]. It sheds light over the primary management of an endemic problem,
corneal ulceration, at the village level. We have a few comments to make.
The study suggests that there is no statistically significant
difference in the rates of fungal corneal ulceration in patients with
corneal abrasions with antifungal prophylaxis or with placebo. The role of
prophylactic antibiotics for the prevention of bacterial corneal ulcers is
yet unclear, even though a few studies have indicated a positive role [2]. We
would like to note that in a rural and largely illiterate population like
India, the mass prescription of an antibiotic drug is certain to lead to
its improper use. Patients may resort to applying the medication for
unrelated eye problems, encouraging complications and antibiotic
resistance. Whether proper counseling can be done at the village health
worker level remains to be seen.
Also, in the study, only 30% of patients with ocular injury had
corneal abrasions. This protocol may lead to the under diagnosis of other
findings not picked up fluorescein-blue light examination, retinal
dialysis or angle recession to name a few. And the process of examination
may instill a false sense of security in the rural patients, preventing
them from seeking ophthalmologic care. The study provided for referral
center evaluation, but it was not clear whether the authors recommend this
as a part of the screening model.
The authors suggest that a rapid epithelialisation and a modest
antifungal effect from the ointment base itself may be the reason for the
reduced incidence of ulceration in their population. A true control
population without any topical medications may have greatly facilitated in
reaching a firm conclusion. However, to the best of our knowledge, the
antifungal effect 1% chloramphenicol base has not been reported. And if
the hypothesis were true, there remains no need to prescribe a blanket
treatment for all corneal erosions, as rapid epithelialisation will
prevent the development of corneal ulcer. An important fact, which cannot
be sidelined, is that severe side effects like aplastic anemia and even
death have been reported on topical application of chloramphenicol
eyedrops [3-5].
In view of the above observations, we would advise all patients with
ocular trauma to undergo an ophthalmologists’ detailed examination.
Patients detected to have corneal abrasions may start antibiotic
prophylaxis in the interim. However, an ophthalmologist’s evaluation must
be the emphatic general policy. As the authors conclude, the unanswered
questions may be solved by future studies.
References
1. Srinivasan M, Upadhyay MP, Priyadarsini B, Mahalakshmi R, Whitcher
JP. Corneal ulceration in southeast Asia III: prevention of fungal
keratitis at the village level in south India using topical antibiotics.
Br J Ophthalmol. 2006 Dec;90(12):1472-5.
2. Maung N, Thant CC, Srinivasan M, Upadhyay MP, Priyadarsini B,
Mahalakshmi R,Whitcher JP. Corneal ulceration in South East Asia. II: a
strategy for the prevention of fungal keratitis at the village level in
Burma.Br J Ophthalmol. 2006 Aug;90(8):968-70.
3. Brodsky E, Biger Y, Zeidan Z, Schneider M.Topical application of
chloramphenicol eye ointment followed by fatal bone marrow aplasia.Isr J
Med Sci. 1989 Jan;25(1):54.
4. Abrams SM, Degnan TJ, Vinciguerra V.Marrow aplasia following
topical application of chloramphenicol eye ointment. Arch Intern Med. 1980
Apr;140(4):576-7.
5. Fraunfelder FT, Bagby GC Jr, Kelly DJ.Fatal aplastic anemia
following topical administration of ophthalmic chloramphenicol.Am J
Ophthalmol. 1982 Mar;93(3):356-60.
Dear Editor
The rising use of Avastin injection for choroidal neovascular membranes and other conditions has been successful in preliminary reports. However, I have experienced 5 cases with optic neuropathy following Avastin injection after an interval of 2-4 months. Although my number of cases is very small, it suggests that a study be conducted to investigate the effect of intravitreal Avastin on the optic nerve u...
Dear Editor
I wish to thank Ganesh et al for confirming (p <0.001) the marked and obvious difference between the age distribution of retinal and subdural haemorrhages in America and Japan. Finding this difference "not surprising" neither negates nor explains it. More sophisticated child abuse teams could not discover cases in Japan months before they occur. Variations in incidence of osteogenesis imperfecta wou...
Dear Editor
The authors would like to thank Dr. J.J. Wang for her constructive comments about the statistical analysis of the data obtained in the Beijing Eye Study.[1] As already pointed out in another recent reply to a letter by Dr. Wang, the authors became aware of the limitations in their statistical analysis of the data of the Beijing Eye Study.[2] The authors are grateful to Dr. Wang for clarifying these wea...
Dear Editor,
I read with interest the report from the Beijing Eye Study by Xu, et al. published in BJO last year (BJO 2006;90:1087-1090), titled: Associated factors for age related maculopathy in the adult population in China: the Beijing Eye Study.
In the abstract, Results and Table 1 of this report, some association estimates are provided as p values and 95% confidence intervals without point estimate...
Dear Editor
We thank Dr. Holló [1] for his comments and the opportunity to elaborate further on our findings. We had considered the point that both eyes from an individual may not be fully independent from one another. As such, in our initial analysis, we calculated the Pearson’s correlation coefficient (r) between left and right eyes for both of our measures. We found the central corneal thickness (CCT) between...
Dear Editor
After going through the above mentioned scientific report, I have some queries and suggestions as mentioned below:
1. Is a surgeon's opinion enough to declare a case as having Vitreomacular traction as mentioned in this study? Or is a definite documentation possible with aid like OCT?
2. In 2 cases, single sessions of PDT were done, which does not match the criterion of repeated...
Dear Editor,
We read the paper titled “Anti-permeability and anti-proliferative effects of standard and frozen bevacizumab on choroidal endothelial cells” by Peters et al [1] in Br J Ophthalmol. Dec. 2006 issue with great interest. There are a number of issues that we would like to point out with regards to the methodology. The authors have solely used scratch assay in the presence of 50ng/ml VEGF +- 0.5mg/ml b...
Dear Editor
We read with great interest Alwitry and coworkers' article[1] on bilateral decompression retinopathy following medical treatment of an acute primary angle closure. We would like to report the case of a 47 year -old woman who consulted in November 2000 for a mildly painful right eye. Pain had lasted for about three days. Visual acuity was 20/20 OU with no optical correction. On slit-lamp examination, b...
Dear editor
I am in strong agreement with Waddell that the treatment of conjunctival neoplasia in Africa should primarily be surgical excision and not medical drugs. As an ophthalmologist working in Malawi-Southern Africa where the prevalence of HIV is very high (8.3% of whole population), conjuctival tumours have become the dominant condition requiring surgery. In 2006 alone a total of 467 cases of advanced con...
Dear editor
We read with great interest the study published by Srinivasan et al [1]. It sheds light over the primary management of an endemic problem, corneal ulceration, at the village level. We have a few comments to make.
The study suggests that there is no statistically significant difference in the rates of fungal corneal ulceration in patients with corneal abrasions with antifungal prophylaxis or wi...
Pages