I read this article with interest.[1] Here, the authors suggest that the
evaluation of the posterior corneal surface topographic changes after
partial flaps without ablation may help us to know the contribution of the
flap to the corneal elasticity and the increase in posterior corneal
elevation following LASIK.
However, I would like to point out that there are some very important
differences between a...
I read this article with interest.[1] Here, the authors suggest that the
evaluation of the posterior corneal surface topographic changes after
partial flaps without ablation may help us to know the contribution of the
flap to the corneal elasticity and the increase in posterior corneal
elevation following LASIK.
However, I would like to point out that there are some very important
differences between a failed flap and a ablatable flap.
Firstly, as in their own study, some patients with partial flaps had the
hinge in the visual axis. This means that in these patients the flaps have
cut half or less of the central corneal bed, compared to a good flap which
cuts through the whole of the central area.
Secondly the so called thin flaps that were not ablated are most likely to
be epithelial or subepithelial flaps with very little stromal tissue.
Due to these facts any conclusions drawn from partial flaps without
ablation, on the possible outcomes of good flaps with ablation are invalid
and erroneous.
References
(1) N Sharma, A Rani, R Balasubramanya, R B Vajpayee, and R M Pandey. Posterior corneal topographic changes after partial flap during laser in situ keratomileusis. Br J Ophthalmol 2003;87:160-162.
We have been conducting high volume cataract surgery (hospital-based
with full fledged ophthalmic facilities) in rural parts of Maharastra
state in India, conducting about 4000 to 5000 thousand sutureless
cataract extractions with lens implantations in last 5 years.
Patients with mature cataract with vision not more than finger counting
at
5 feet are selected. They all undergo routine eye exams and...
We have been conducting high volume cataract surgery (hospital-based
with full fledged ophthalmic facilities) in rural parts of Maharastra
state in India, conducting about 4000 to 5000 thousand sutureless
cataract extractions with lens implantations in last 5 years.
Patients with mature cataract with vision not more than finger counting
at
5 feet are selected. They all undergo routine eye exams and physical
check ups pre-operatively. We use a frown incision 7 to 7.5mm (white
mature or dark brown cataracts don't get expressed with the
viscoelastics method for incisions smaller then this). Post-op
refraction is done after 6 weeks; the average cylinder is about 1.5 D at
90 degrees.
Unfortunately, we don't have any method to compile this data. Also
follow-up after the final refraction is very poor. I would be grateful
if you could suggest a means to compile this data and utilize it in the
future. We would welcome any suggestions from you.
We thank Drs Sharawary and Mermoud for their interest in our article [1]
and respect their observations. They have made significant contributions
to our understanding of non penetrating surgery in the treatment of
chronic open angle glaucoma.
With any new surgical technique information changes rapidly, and much new
information has appeared since our article was written. The authors note
current li...
We thank Drs Sharawary and Mermoud for their interest in our article [1]
and respect their observations. They have made significant contributions
to our understanding of non penetrating surgery in the treatment of
chronic open angle glaucoma.
With any new surgical technique information changes rapidly, and much new
information has appeared since our article was written. The authors note
current literature as well as the effects of 'the learning curve' that
might affect results. The point of our article was to summarise the then
position and suggest outcome measures to note for the future.
As chronic glaucoma is a very long term disease even medium term results
can only give at best give an indication of the visual outcome of
treatment. Our current knowledge of treatment for these glaucoma's
strongly suggests that the lower the intraocular pressure within the
statistically normal range the better. The evidence to date still suggests
that there is a greater likelyhood of these lower intraocular pressures
being achieved by 'penetrating' rather then 'non penetrating' surgery.
This needs to be taken into account when advising the patient on which
surgical approach would be in their best interest.
Roger Hitchings
Reference
(1) Tan JCH, Hitchings RA. Non-penetrating glaucoma surgery: the state of play. Br J Ophthalmol 2001;85: 234-237.
Regarding the editorial by Khaw et al.[1]
we are surprised that after quite a few years now non-
penetrating filtering surgery (NPFS) remains only
partly understood by many ophthalmologists. There are
at present two main NPFS: viscocanalostomy as
described by Stegmann, in which outflow filtration is at
least in theory not subconjunctival, and deep
sclerectomy with or without an implant or even wi...
Regarding the editorial by Khaw et al.[1]
we are surprised that after quite a few years now non-
penetrating filtering surgery (NPFS) remains only
partly understood by many ophthalmologists. There are
at present two main NPFS: viscocanalostomy as
described by Stegmann, in which outflow filtration is at
least in theory not subconjunctival, and deep
sclerectomy with or without an implant or even with
viscoelastics, the success of which depends on
several outflow routes - an important one being
subconjunctival. Careful postoperative follow up
becomes therefore mandatory and is at least as
important as the procedure itself. If needed
subconjunctival injection of antimetabolites, needling or use of lasers for
goniopuncture, iris
desincarceration and attempts of possible bleb
reduction or closure of possible seidel may be
required. It also becomes evident that
antimetabolites play an important role in high risk
cases for filtration failure undergoing NPFS (apart
from viscocanolostomy as describd by Stegmann).
Furthermore in our hospital we have been using
antimetabolites also in cases requiring low
postoperative IOP such as normal tension glaucoma
since 1994. We do not understand the comment made
stating that greater care should be taken with
antimetabolites used during NPFS, since we
intraoperatively use these agents before the deeper
scleral flap is being excised or even created. Thus
at this stage this does not differ with
trabeculectomy. Later on the anterior chamber is not
entered and furthermore the deep scleral flap which
has been exposed to antimetabolites is being excised
making the danger of intraoperative intraocular
penetration considerably less than with
trabeculectomy (even with unintended macroperforation
during NPFS).
Additional sutures are added in cases of accidental
macroperforaton so that the incidence of early
significant hypotony in the hands of experienced
surgeons with NPFS is not high. Moreover
postoperative suturelysis may then be required in
these cases if the sutures have been made too tight
or too numerous.
References are being made to the article by Brart et al. However how
reliable is it to compare the
efficacy of two procedures without giving the same
chances of success to both? Intraoperative
antimetabolites were used for all trabeculectomies
and yet never with NPFS. Yet strangely enough,
postoperative antimetabolites as well as needling
with an attempt to lift the scleral flap in some,
were used in both groups. The author also writes in
the discussion that patients with successful drainage
at 6 and 12 months following viscocanalostomy had
evidence of subconjunctival drainage of aqueous as
opposed to eyes without successful drainage. Later on
he further states that 'with our viscocanalostomy
technique, the subconjunctival route is the main
pathway' and 'observation of the disappearance of
subconjunctival blebs in our patients with drainage
failure after viscocanalostomy appears to suggest
that subconjunctival fibrosis is responsible'.
Clearly, if antimetabolites are being used in
trabeculectomies, it should be used in NPFS before
any reliable conclusions can be drawn.
Goniopunture was also only done after 18 months which
of course will not be of great help if the outflow
route after the trabeculodescemet's membrane has
scarred down. Thus to promote good filtration in
addition to intraoperative and postoperative use of
antimetabolites, goniopuncture can help in enhancing
and thus in maintaining a flow under the scleral flap.
Using lasers for suturelysis in trabeculectomies or
for goniopuncture in NPFS is part of the
armementarium we have in glaucoma surgery. The final
aim for the patient is not to know whether the
procedure is penetrating or not, but rather how
effective it is so that the discussion on whether or
not to use goniopunture is futile.
For ophthalmologists performing NPFS, the later is
compared to trabeculectomy what phacoemulsification
was to extracapsular cataract extraction. They will
never go back to it unless obliged to do so. However
it is clear that there is a learning curve to this
surgery and that it is not as forgiveful as is
trabeculectomy.
E. Ravinet, MD
A. Mermoud, MD
Reference
(1) Khaw PT, Wells AP, Lim KS. Surgery for glaucoma in the 21st
century. Br J Ophthalmol 2002;86:
710-711.
I found your editorial on glaucoma in the 21st century to be
fascinating.[1] Not only did you give us insight as to where we are in the
field, but you certainly give us provocative insight into where we might
be headed in the pursuit of the perfect glaucoma procedure.
I would like to state at the onset that I have a financial interest
in product involved in this discussion, having develop...
I found your editorial on glaucoma in the 21st century to be
fascinating.[1] Not only did you give us insight as to where we are in the
field, but you certainly give us provocative insight into where we might
be headed in the pursuit of the perfect glaucoma procedure.
I would like to state at the onset that I have a financial interest
in product involved in this discussion, having developed the device which
is presently FDA approved in the United States for anterior capsulotomy
called the Fugo Blade™. In many other parts of the world, this device is
referred to as the Plasma Blade.
The device operates on flashlight size
rechargeable batteries and with this minute power can cut sharper than a
diamond blade with a total cut time of one hour duration. Best stated by
Dr I. Howard Fine, the device operates "like a miniature eximer laser" .
Namely, the device creates an ablation path by employing a focused photon
ablation of tissue with quanta of electromagnetic energy. This does sound
incredible but to quote the last sentence in your editorial "Impossible?
Only if you think so."
There are over 500 doctors trained and certified
in the United States in this technology. The doctors on our certification
list include such notable surgeons such as I Howard Fine, F. Hampton Roy,
Luther Fry, Gregory Scimeca, David Schanzlin, Jan Worst and Dr Daljit
Singh. Dr Jan Worst of the Netherlands has stated, "This device can
change the entire field of surgery, not just ophthalmic surgery. " Dr
Daljit Singh of Amritsar, India has stated, "This is the greatest cutting
device that I have ever used".
There are those who have not used this
device who state that it is merely another electro-cautery unit. The Fugo
Blade™ absolutely has nothing to do with electro-cautery or diathermy.
Consider that it can be operated on batteries as small as coin size,
wristwatch batteries. Yes, this is a new approach to electrosurgery. Such
a new device allows us to perform surgeries, which heretofore were
considered to be impossible just as you discuss in your article. Incisions
are resistance free and bloodless . You can ablate through highly
vascularized tissue such as uveal tissue which will be resistance free and
bloodless. This opens up incredible possibilities for glaucoma surgery.
Dr Daljit Singh of Amritsar, India is presently performing what you
mentioned in the last paragraph of your editorial namely a 5-minute
glaucoma procedure. This is called Transciliary Filtration or Singh
Filtration. We do not have 95% of the patients achieving pressures of 10-12 mm Hg for several decades. However, we do have an impressive success
rate with not a single collapsed anterior chamber in approximately 200
cases in our clinicals. No iridotomy is needed and a 1 cm conjunctival
flap is required. We also are obtaining penetrating insight into the
homeostatic mechanisms in the eye and an enhanced understanding of how the
eye works.
Employing the Fugo Blade™, Dr Daljit Singh has been able to
demonstrate stunning videos of an extensive lymphatic system that exists
subconjunctivally. He showed these videos at the most recent meeting
of ACES, ASCRS and ISRS. He has obtained these findings in human subjects
employing vital stain and based on data obtained by Fugo Blade™ histologic
sections.
We have seen that this subconjunctival lymphatic system is
imperative for homeostasis of tissue fluid in the globe. The exact
microanatomy of this lymphatic system is being worked out. However, we see
a highly suggestive correlation between the lymphatic feeder channels and
Schlemm's canal. These feeder channels sit above Schlemm's canal. We are
beginning to believe that this lymphatic system plays a major role in the
management of extracellular fluid in any pathologic process such an
inflammation or infection but also rules highly in the management of
aqueous fluid exiting from Schlemm's canal.
Also, we find that our studies
demonstrate that a filtration track placed through sclera in an area which
has deficient lymphatics will produce a large bleb, however will not
produce anticipated drop in IOP. Initially, this was confusing; however,
it appears that the mechanism here is that the intraocular aqueous is
escaping through the filtration tract and accumulates under the
conjunctiva. Since the conjunctiva lacks appropriate lymphatics, there is
a large accumulation of aqueous under the conjunctiva thereby creating a
large filtering bleb that lacks the ability to drain the aqueous fluid
back through the orbit and into the vascular system . Dr. Singh's work
will force us to rethink not only our surgical approach to glaucoma but
also, as you suggest in your editorial, our thoughts and concepts about
how the eye functions.
The number of applications that are presently under study in humans
include bloodless plastic surgery, bloodless squint surgery, Fugo Blade™
phacofragmentation, bloodless ablation of fibrovascular bands that exist
in severe retinopathy, and a new procedure coined by Dr. Singh as " Peep
Hole" DCR . This procedure takes about 3-5 minutes wherein a micropore
ablation path is placed through the medial cathal conjunctiva and into the
dacryocyst, providing a port for evacuation of necrotic debris from the
dacryocyst. Also, the ablation path allows probing and flushing of the
area with antibiotic. This has produced excellent results to date on the
10 operated patients. We also are working on exciting protocols for DLEK
and lamellar corneal grafts. Likewise, we now have a marvelous tool which
may bring a quick, repeatable and efficacious presbyopia reversal surgery
into the realm of reality in the foreseeable future. A senior executive of
one of our large ophthalmic companies has called this technology: "the
greatest fundamental technology since the implementation of the laser".
Numerous articles have appeared on this device in the USA since
this device is FDA approved and over 500 American ophthalmologists have
taken a course in this technology and have been certified to use the
technology. Dr I. Howard Fine chose the Fugo Blade as one of the top
eight technologies at the 2002 ASCRS Meeting.2 The technology will be
introduced into the European market and into Japan in 2003. Only a few
lectures on this topic have been given to date outside of the USA and
those include lectures given by Dr I. Howard Fine and Dr Daljit Singh.
Dr David Apple has performed Fugo Blade capsulotomy margin histologic
analysis and presented this data in his Keynote Innovators Lecture at the
2002 ASCRS meeting in Philadelphia. He explained why the Fugo Blade
capsule margin is "desirable" based on his analysis as well as the
authoritative studies of Assia.
Your editorial correctly points out that surgical techniques must be
accompanied by improved understanding. This new technology may help
greatly in this quest. Dr Daljit Singh calls the Plasma Blade "the great
leveler". He firmly believes that this technology may provide an
opportunity to deliver much needed ophthalmic care to the 3rd World. If
this comes to pass, wouldn't it be grand!
Richard J. Fugo MD, PhD
Reference
(1) P T Khaw, A P Wells, and K S Lim. Surgery for glaucoma in the 21st century. Br J Ophthalmol 2002; 86: 710-711.
We read with great interest the article of Orge and co-workers[1] who
claim a first-ever solution to the problem of non-invasive volumetric
blood flow measurement in the ophthalmic artery. This is a very important
topic both from the clinical and scientific point of view, since blood
supply is an important parameter for example in glaucoma studies. However,
to date for the orbital circulation only the bl...
We read with great interest the article of Orge and co-workers[1] who
claim a first-ever solution to the problem of non-invasive volumetric
blood flow measurement in the ophthalmic artery. This is a very important
topic both from the clinical and scientific point of view, since blood
supply is an important parameter for example in glaucoma studies. However,
to date for the orbital circulation only the blood velocity has been
measurable; from this the resistivity indices can be calculated, but the
volumetric flow cannot be determined because the small diameter of the
orbital vessels does not allow the vessel diameter measurement which is
indispensable for such calculation.
In spite of the novelty of the report and the extensive analysis of
the authors on the possible sources of high variability of volumetric flow
measurements, it appears to us that there are several points which need
further consideration; some of these were analysed in the Editorial by T R
Hedges,[2] but we would like to highlight two additional questions.
For us, a weak point of the study protocol of Orge and colleagues[1] is
their method for the diameter determination of the ophthalmic artery. They
assume the boundaries of the vessel to be where detected movement starts
and ends along the m-mode line; or in other words the vessel boundaries
are taken to be the positions where the grey pixels and colour pixels
touch on this Doppler image. However, we are doubtful whether this
definition is relevant for the required quantitative measurement. The
first point is that for small vessels the width of the colour area
(indicating blood motion) is unfortunately relatively independent of the
true vessel diameter. The width of the superimposed colour area is greatly
influenced by the actual technical parameters used in color Doppler
imaging (pulse repetition frequency, lateral dimension of the ultrasound
beam, colour priority, motion discriminator setting, colour saturation,
brightness, contrast, etc). Our second doubt is that even on the grey-scale part of the image shown by the present authors in their Figure 1, no
vessel wall is seen, unlike the case for typical images of large vessels
like the carotid arteries.
We think that because of these difficulties regarding the
determination of the vessel wall position, Orge and co-workers
overestimate the ophthalmic artery diameter. Their diameter estimate is
2.02 mm on average; but this figure is significantly larger than is
suggested by other evidence. During conventional 10 MHz B-scan diagnostic
examination, the ophthalmic artery is never visible. However for the
dilated ophthalmic vein, in exceptional cases such as in a patient with
carotideo-cavernous sinus fistula, or in a small baby in a bout of
strenuous crying, the vein is then well outlined with a diameter of 1 mm
or above. Thus, we would expect a 2 mm diameter artery to be clearly
visible. As we demonstrated some years ago,[3,4] patients with a
pathologically dilated ophthalmic vein are good candidates for non-
invasive volumetric blood flow measurement. We were able to measure
volumetric blood flow in the orbit of patients with a high flow fistula
(vein diameter around 3-4 mm) using the CVI-Q technique.
Possibly future improvements in spatial resolution may resolve this
difficulty.
In a vessel like the ophthalmic artery there is a further problem in
determination of the average velocity, because the laminar flow in such
small vessels causes a very wide velocity variation within the lumen. In contrast, we note that the colour
spectrum in the figure presented by the authors is almost completely
uniform and does not show higher speed in the centre of the lumen compared
to that close to the vessel wall. This might imply a relatively
insensitivity of velocity discrimination within a small vessel lumen,
which in addition may be of irregular cross-sectional shape (i.e. not
circular) but is only measured in one longitudinal plane. We agree with
the authors that the analysis software is of great importance and may be a
key factor in dealing with this complex situation.
In spite of our reservations mentioned above we, and many other
workers concerned with orbital circulation, are in urgent need of a
reliable solution for volumetric blood-flow determination in the orbit.
The results of Orge and co-workers[1] show that we are probably not far from
a definitive solution.
References
(1) Orge F, Harris A, Kagemann L et al. The first technique for non-
invasive measurements of volumetric ophthalmic artery blood flow in
humans. Br J Ophthalmol 2002;86:1216-9.
(2) Hedges TR. Ophthalmic artery blood flow in humans. The tortuosity and
the variable course of the ophthalmic artery remain a problem. Br J
Ophthalmol 2002;86:1197.
(3) Németh J, Harkányi Z. Color Doppler and color velocity imaging of the
orbital vessels
In: Süveges I, Follmann P, (Eds) XIth Congress of the European Society of
Ophthalmology. Bologna: Monduzzi. 1997:593-6.
(4) Németh J, Süveges I, Harkányi Z. Color Velocity Imaging of Orbital
Blood Circulation
In: Hasenfratz G. (Ed.) Ultrasound in Ophthalmology, Proceedings of the 16th
SIDUO Congress Munich, Germany 1996. Regensburg: Roderer Verlag. 2000:31-3.
2
We read with keen interest the paper by Kageyama et al,[1] which analyzed the
results of performing phacoemulsification with dominant versus non-dominant hand. The
results were also interesting; vitreous loss was higher with dominant hand group (5.9%
vs.3.4%) and opposite in case of endothelial cell loss. Even though vitreous loss has been
similar to a few other reports of conventional superior inc...
2
We read with keen interest the paper by Kageyama et al,[1] which analyzed the
results of performing phacoemulsification with dominant versus non-dominant hand. The
results were also interesting; vitreous loss was higher with dominant hand group (5.9%
vs.3.4%) and opposite in case of endothelial cell loss. Even though vitreous loss has been
similar to a few other reports of conventional superior incision by trainees, there are also
studies that reports lesser percent of vitreous loss (Prasad et al.:2.9%,[2] Corey RP et al:
1.8%,[3] Seward et al: 1.5%,[4] Pedersen et al: 2.1%[5]). The favourable results for non-dominant
hands could have been due to chance since the trainees were not picked up
randomly. Intraoperative complications could have been probably low if trainees were
allowed to operate on all eyes with their dominant hands as in our institution.
Briefly, in our system each operating surgeon operates on two tables with a
microscope set to swing between tables. Two surgeon’s chairs are placed on the sides of
operating tables. While the surgeon operates on one table, another patient is prepared for
surgery on the other table. After completion of surgery, the surgeon swings the
microscope to the other table and operates on the next patient. Assisting nurses are
trained to designate right and left eye surgery patient to right and left tables, respectively.
This automatically makes surgeons sit on temporal side and operate with their dominant
hand. There is no need for repositioning chairs or equipments, increase staff or a high risk
of infection in our system.
References
(1) T Kageyama, S Yaguchi, Y Metori, et al. Visual results and complications of
temporal incision phacoemulsification performed with non-dominant left hand by
junior ophthalmologists. Br J Ophthalmol 2002; 86:1222-1224
(2) Prasad S. Phacoemulsification learning curve: experience of two junior trainee
ophthalmologist. J Cataract Refract Surg 1998; 24:73-77.
(3) Corey RP, Olson RJ.Surgical outcomes of cataract extractions performed by
residents using phacoemulsification. J Cataract Refract Surg 1998; 24:66-72
(4) Seward HC, Dalton R, Davis A. Phacoemulsification during the learning curve:
risk/benefit analysis. Eye 1993 ; 7:164-168.
(5) Pedersen OO. Phacoemulsification and intraocular lens implantation in patients with
cataract. Experiences of a beginning ‘phacoemulsification surgeon’. Acta Ophthalmol
1990; 68:59-64.
We read with interest the article on immediate sequential phacoemulsification
(ISP) by Wertheim et al.[1] Bilateral intraocular surgery has been a controversial topic for
ophthalmologist because of the risk of bilateral catastrophic complications such as
endophthalmitis. Unilateral cataract surgery may result in anisometropia which can be
debilitating for a person who could have been performing fine...
We read with interest the article on immediate sequential phacoemulsification
(ISP) by Wertheim et al.[1] Bilateral intraocular surgery has been a controversial topic for
ophthalmologist because of the risk of bilateral catastrophic complications such as
endophthalmitis. Unilateral cataract surgery may result in anisometropia which can be
debilitating for a person who could have been performing fine jobs comfortably before
the onset of cataract or even with a pair of corrective glasses after the onset of cataract. In
developing countries, bilateral intraocular surgery is done mostly in patients who have
dense cataracts obscuring vision totally in both eyes and usually done after a few days
after the first surgery.
A recent study by Minasian et al. argues that scheduled outpatient visits
(preoperatively and postoperatively) and unscheduled visits could have manifested as a
major patient cost component of cataract surgery.[2] Unpublished data from our institute
reveals that patients cost were at least 1.5 times lesser for Phacoemulsification compared
to Extracapsular Cataract Extraction with Posterior Chamber Intraocular Lens.
Extrapolating the scenario to sequential bilateral surgeries, the economic benefits would
be much more.
This technique is of particular relevance to developing countries like India as it
curtails cost of scheduled and unscheduled visits and cost of buying spectacles. As recent
surgical techniques and preoperative prophylaxis resulting in reduced incidence of
endophthalmitis[3] is becoming available in developing countries like India, bilateral
cataract surgery can greatly reduce cost to providers and patients. However, more clinical
trials are required in developing countries for adopting sequential surgeries as a policy,
which can be an incentive for increasing number of cataract surgeries.
References
(1) Werthiem M, Burtan R. Immediately sequential phacoemulsification performed
under topical anaesthesia as day case procedures. Br J Ophthalmol 2002;86:1356-58.
(2) Minassian DC, Rosen P, Dart JKG et al. Extracapsular cataract extraction
compared with small incision cataract surgery by phacoemulsification a
randomized trial. Br J Ophthalmol 2001; 85: 822-29.
(3) Schmitz S, Dick HB, Krummenauer F, Pfeiffer N. Endophthalmitis in cataract
surgery. Ophthalmology 1999;106:1869-77.
I read with interest your paper the effect of acitretin on interstitial
keratitis. However, I am left with a few questions. First, you suggest the
interstitial keratitis in your patient was due to tuberculosis, but you do
not comment on diagnostics: was a PCR performed on aqueous fluid? was the
button of the left eye in 1993 histologically examined?
Secondly, on the photograph there seems to be a hypopyon p...
I read with interest your paper the effect of acitretin on interstitial
keratitis. However, I am left with a few questions. First, you suggest the
interstitial keratitis in your patient was due to tuberculosis, but you do
not comment on diagnostics: was a PCR performed on aqueous fluid? was the
button of the left eye in 1993 histologically examined?
Secondly, on the photograph there seems to be a hypopyon present in an
otherwise quiet eye. Could you comment on that?
Of course you must proceed to a cycloplegic refraction, otherwise you
cannot be sure that the refractive error is purely astigmatic. The sign of
the astigmatism may also change after cycloplegia. Moreover, be cautious
about the cylinder value given by the Retinomax if the spherical ametropia
is high.[1]
Reference
(1) How accurate is the hand-held refractor Retinomax in measuring cyclople...
Of course you must proceed to a cycloplegic refraction, otherwise you
cannot be sure that the refractive error is purely astigmatic. The sign of
the astigmatism may also change after cycloplegia. Moreover, be cautious
about the cylinder value given by the Retinomax if the spherical ametropia
is high.[1]
Reference
(1) How accurate is the hand-held refractor Retinomax in measuring cycloplegic refraction : a further evaluation" Strabismus. 19866;3:133-142.
Dear Editor
I read this article with interest.[1] Here, the authors suggest that the evaluation of the posterior corneal surface topographic changes after partial flaps without ablation may help us to know the contribution of the flap to the corneal elasticity and the increase in posterior corneal elevation following LASIK. However, I would like to point out that there are some very important differences between a...
Dear Editor
We have been conducting high volume cataract surgery (hospital-based with full fledged ophthalmic facilities) in rural parts of Maharastra state in India, conducting about 4000 to 5000 thousand sutureless cataract extractions with lens implantations in last 5 years.
Patients with mature cataract with vision not more than finger counting at 5 feet are selected. They all undergo routine eye exams and...
Dear Editor
We thank Drs Sharawary and Mermoud for their interest in our article [1] and respect their observations. They have made significant contributions to our understanding of non penetrating surgery in the treatment of chronic open angle glaucoma.
With any new surgical technique information changes rapidly, and much new information has appeared since our article was written. The authors note current li...
Dear Editor
Regarding the editorial by Khaw et al.[1] we are surprised that after quite a few years now non- penetrating filtering surgery (NPFS) remains only partly understood by many ophthalmologists. There are at present two main NPFS: viscocanalostomy as described by Stegmann, in which outflow filtration is at least in theory not subconjunctival, and deep sclerectomy with or without an implant or even wi...
Dear Editor
I found your editorial on glaucoma in the 21st century to be fascinating.[1] Not only did you give us insight as to where we are in the field, but you certainly give us provocative insight into where we might be headed in the pursuit of the perfect glaucoma procedure.
I would like to state at the onset that I have a financial interest in product involved in this discussion, having develop...
Dear Editor
We read with great interest the article of Orge and co-workers[1] who claim a first-ever solution to the problem of non-invasive volumetric blood flow measurement in the ophthalmic artery. This is a very important topic both from the clinical and scientific point of view, since blood supply is an important parameter for example in glaucoma studies. However, to date for the orbital circulation only the bl...
Dear Editor
2 We read with keen interest the paper by Kageyama et al,[1] which analyzed the results of performing phacoemulsification with dominant versus non-dominant hand. The results were also interesting; vitreous loss was higher with dominant hand group (5.9% vs.3.4%) and opposite in case of endothelial cell loss. Even though vitreous loss has been similar to a few other reports of conventional superior inc...
Dear Editor
We read with interest the article on immediate sequential phacoemulsification (ISP) by Wertheim et al.[1] Bilateral intraocular surgery has been a controversial topic for ophthalmologist because of the risk of bilateral catastrophic complications such as endophthalmitis. Unilateral cataract surgery may result in anisometropia which can be debilitating for a person who could have been performing fine...
Dear Editor
I read with interest your paper the effect of acitretin on interstitial keratitis. However, I am left with a few questions. First, you suggest the interstitial keratitis in your patient was due to tuberculosis, but you do not comment on diagnostics: was a PCR performed on aqueous fluid? was the button of the left eye in 1993 histologically examined? Secondly, on the photograph there seems to be a hypopyon p...
Dear Editor
Of course you must proceed to a cycloplegic refraction, otherwise you cannot be sure that the refractive error is purely astigmatic. The sign of the astigmatism may also change after cycloplegia. Moreover, be cautious about the cylinder value given by the Retinomax if the spherical ametropia is high.[1]
Reference
(1) How accurate is the hand-held refractor Retinomax in measuring cyclople...
Pages