1. Adhesion to the capsule works even during implantation of IOLs. As the
acrylate material IOLs seem to have a higher adhesion tendency they
require a lubricant viscoelastic material during rotation and positioning.
This is why it is more difficult to rotate an acrylate IOL
while using an AC maintainer and no viscoelastics. Silicone and PMMA IOLs
do not...
1. Adhesion to the capsule works even during implantation of IOLs. As the
acrylate material IOLs seem to have a higher adhesion tendency they
require a lubricant viscoelastic material during rotation and positioning.
This is why it is more difficult to rotate an acrylate IOL
while using an AC maintainer and no viscoelastics. Silicone and PMMA IOLs
do not suffer this disadvantage.
2. I would like to know from the authors if they find any difference in results between hydrophilic and hydrophobic acrylate IOLs?
The paper by El Mallah, et al. [1], reporting visual recovery in the amblyopes after visual loss in the non-amblyopic eye brings new evidence for visual system plasticity extending beyond what was considered the critical period. Our observation of two patients presented below further supports it and suggests plasticity may be pharmacologically enhanced.
The paper by El Mallah, et al. [1], reporting visual recovery in the amblyopes after visual loss in the non-amblyopic eye brings new evidence for visual system plasticity extending beyond what was considered the critical period. Our observation of two patients presented below further supports it and suggests plasticity may be pharmacologically enhanced.
A 22-year-old woman with strabismic amblyopia in the right eye (visual acuity 0.7) developed left optic neuritis with loss of acuity from 1.0 to 0.2. She received methylprednisolone 1 g/day i.v. for 3 days. Acuity improved over 2 weeks to 1.0 right (amblyopic) eye and to 0.8 in the left eye. The improvement was sustained over 2 years of observation. She subsequently developed definite multiple sclerosis (MS). The second patient was a 19-year-old woman with strabismic amblyopia in the right eye (visual acuity 0.2), and MS since age 8, with aggressive course after age 15. Frequent relapses, mainly myelopathic and cerebellar, responded to steroids. She had 3 days of i.v. steroids for a myelopathic relapse, and recovered. One month later she developed left optic neuritis (acuity 0.2). She noted an improvement in acuity (to 0.4) in the right eye. She received i.v. methylprednisolone for 3 days. Four weeks later, visual acuity had improved to 1.0 in the right eye but only to 0.3 in the left eye. A repeat course of steroids led to marginal further improvement in the left eye. The amblyopic eye recovery was sustained for over 18 months of follow-up.
These cases show that improvement in amblyopia can occur after optic neuritis in the fellow eye. The significant improvement may reflect the patients' younger ages, but also raises the fascinating possibility that pharmacological modulation with steroids may enhance or prolong the recovery effect. Other agents enhancing plasticity improve adult amblyopia [2], and steroids, which affect neural plasticity [3], may be a future consideration.
CS Constantinescu
I Gottlob
Leicester Royal Infirmary
Leicester LE2 7LX, UK
REFERENCES
(1) El Mallah MK, Chakravarthy U, Hart PM. Amblyopia: is visual loss permanent? Br J Ophthalmol 2000;84:952-956.
(2) Gottlob I, Stangler-Zuschrott E. Effect of levodopa on contrast sensitivity and scotomas in human amblyopia. Invest Ophthalmol Vis Sci 1990;31:776-780.
(3) Cameron SA, Dutia MB. Lesion-induced plasticity in rat vestibular nucleus neurones-dependent on glucocorticoid receptor activation. J Physiol (Lond) 1999;518:151-158
We found that the reported incidence of approximately 1 per 2,000 (or
50 per 100,000) per year, and prevalence (54.5 per 100,000) of keratoconus
reported by Bawazeer et al,[1] present some contradictions and formal
imprecision.
Incidence is a dynamic morbidity rate, which indicates the number of
new cases occurring during a specified period of time, over the population
at risk in the same per...
We found that the reported incidence of approximately 1 per 2,000 (or
50 per 100,000) per year, and prevalence (54.5 per 100,000) of keratoconus
reported by Bawazeer et al,[1] present some contradictions and formal
imprecision.
Incidence is a dynamic morbidity rate, which indicates the number of
new cases occurring during a specified period of time, over the population
at risk in the same period. Prevalence is a static measure, expressing the
number of cases in the population at a specified time, over the number of
people in the population at that time.[2] For acute diseases, incidence
and prevalence are similar, because the cases do not accumulate (indeed
prevalence is approximately equal to incidence´duration of disease).
Keratoconus is neither acute nor self-resolving, and it does not affect
the life expectancy of affected people.[3] Therefore, its prevalence and
incidence are expected to be different.
In evaluating published data, it is important to pay attention to the
measure reported by the investigator, since the term "incidence" is
sometimes applied to data when prevalence is actually being measured. The
prevalence of keratoconus reported in the literature varies considerably,
estimates range from 4 to 600 people per 100,000. Rabinowitz 4 reports a
prevalence of 54.5 per 100,000 and a similar incidence of 1 per 2,000;
Kennedy et al[5] found a prevalence rate of 54.5 per 100,000 and a much
lower incidence of 2 per 100,000. For the reasons mentioned above, we
think that the last are the keratoconus epidemiological rates to be
quoted. This observation does not undermine the conclusions of Bawazeer's
interesting paper on atopy and keratoconus.
D Ponzin
AC Frigo
(1) Bawazeer AM, Hodge WG, Lorimer D. Atopy and keratoconus: a
multivariate analysis. Br J Ophthalmol 2000;84:834-6.
(2) Lilienfeld AM, Lilienfeld DE. Foundations of epidemiology. 2nd
edition, Oxford University Press 1980, New York; 133-65.
(3) Moodaley LCM, Wooward EG, Liu CSC, et al. Life expectancy in
keratoconics. Br J Ophthalmol 1992;76:590-1.
(4) Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998;42:297-319.
(5) Kennedy RH, Bourne WM, Dyer JA. A 48-year clinical and epidemiological
study of keratoconus. Am J Ophthalmol 1986;101:267-73.
The recent article by Newsom et al.[1] on transpupillary
thermotherapy (TTT) raises more questions than it is able to answer.
Although TTT is definitely a method which seems to show a certain efficacy
in occult choroidal neovascularization (CNV) and thus warrants further
investigation, we must take issue with the authors' conclusions concerning
its use in classic CNV.
The recent article by Newsom et al.[1] on transpupillary
thermotherapy (TTT) raises more questions than it is able to answer.
Although TTT is definitely a method which seems to show a certain efficacy
in occult choroidal neovascularization (CNV) and thus warrants further
investigation, we must take issue with the authors' conclusions concerning
its use in classic CNV.
The authors state that 78% of the predominantly occult membranes and
75% of the predominantly classic membranes closed as a result of TTT.
This seems hard to believe, in particular because only 24 of 44 patients
had angiographic follow-up, which is the criterion for determining CNV
closure. Furthermore, how is the irradiance used to be understood? On
the one hand, the authors state-without providing any evidence-that
smaller lesions need a higher irradiance, but on the other hand larger
lesions-which are presumably requiring only lower irradiance-received
confluent treatment with several overlapping spots of TTT, which implies
that the amount of irradiance necessary on a cumulative basis might be
similar to the irradiance needed to treat smaller lesions!
The authors also state that TTT compared well with the results of the
TAP Study group for predominantly classic CNV.[2] They imply that the 75%
of their cases which showed stabilized vision (9 eyes with a visual loss
of less than 3 lines) can be compared with the TAP results at one year
(246 eyes with a visual loss of less than 3 lines). Firstly, the TAP
study was a masked and placebo-controlled multi-center study performed on
609 patients which without doubt has a much higher statistical value than
the present study with twelve predominantly classic membranes.
Secondly, Newsom et al. cannot compare their visual results
adequately as the TAP study used a standardized testing procedure
employing Early Treatment for Diabetic Retinopathy charts as well as
masked and certified vision examiners in comparison to the Snellen values
mentioned in the above study, which were obtained by unmasked, and
therefore biased, examiners. Furthermore, on closer examination of the
results, not one of the twelve patients showed any improvement for visual
acuity at twelve months after TTT; in comparison, in the TAP study 5.7% of
all verteporfin treated patients showed an improvement of more than 15
letters (approx. 3 lines) at the twelve months visit.
While we recognize the potential of the TTT method, we would like to warn
against extrapolating the data of this study in a relatively small patient
cohort to make conclusions on the efficacy in treating classic CNV.
ERDEM ERGUN, MD
MICHAEL STUR, MD
References
(1) Newsom RSB, McAlister JC, Saeed M, McHugh JDA. Transpupillary
thermotherapy (TTT) for the treatment of choroidal neovascularization. Br
J Ophthalmol 2001;85;173-178.
(2) Treatment of age-related macular degeneration with photodynamic
therapy (TAP) study group. Photodynamic therapy of subfoveal choroidal
neovascularization in age-related macular degeneration with verteporfin.
One-year results of 2 randomized clinical trials - TAP report 1. Arch
Ophthalmol 1999;117;1329-1345.
I thank Van den Bosch for his interest in my paper[1] on the role of
the suborbicularis oculi fat (SOOF) lift in the rehabilitation of patients
with chronic facial palsy. The aim of my paper was to describe the
lateral tarsal strip (LTS)[2,3] in conjunction with a SOOF lift in the
correction of lower eyelid "sag" or paralytic ectropion. The use of this
procedure was confined to patients in whom, pre...
I thank Van den Bosch for his interest in my paper[1] on the role of
the suborbicularis oculi fat (SOOF) lift in the rehabilitation of patients
with chronic facial palsy. The aim of my paper was to describe the
lateral tarsal strip (LTS)[2,3] in conjunction with a SOOF lift in the
correction of lower eyelid "sag" or paralytic ectropion. The use of this
procedure was confined to patients in whom, pre-operatively, there was co-
existent mid-face ptosis which could be elevated digitally, mimicking the
anticipated surgical outcome. My paper did not suggest that the
combination of LTS and SOOF should be used routinely for all cases of
paralytic ectropion. Probably only one in four patients with chronic
facial palsy would be suitable for this procedure.
Measurement of palpebral aperture and lagophthalmos used in this
study provides data relating to the lower eyelid raising but not the mid-
face raising. I found that the SOOF lift was best in longstanding facial
palsy, such as congenital or childhood onset, where the cheek tissue was
slightly atrophic and the mid-face lift sustained.
A LTS alone does not always adequately reduce lagophthalmos in facial
palsy, therefore other techniques and variations of LTS are sought. Direct
comparison with other series is often difficult as patient selection may
differ and other confounding influences may be present. A randomised
prospective trial is a counsel of perfection. It is probably inappropriate
at this stage in the development of the technique, when patient selection
and optimal techniques are yet to be fully determined. In practice, it is
unlikely that sufficient numbers of patients would consent to take part in
such a study. For a randomised study to produce accurate results both
patient selection and operative technique need to be unchanged for a large
number of patients.
JANE M. OLVER FRCOphth
Oculoplastic and Orbital Service,
Western Eye Hospital
Marylebone Road
London NW1 5YE, UK
(1) Olver Jane M. Raising the suborbicularis oculi fat (SOOF): its
role in chronic facial palsy. Br J Ophthalmol 2000,84:1401-1406
(2) Olver Jane M. Surgical tips on the lateral tarsal strip. Eye
1998,12:1007-1012
(3) Van den Bosch WA, Rosman M, Stijnen T. Involutional lower eyelid
entropion: results of a combined approach. Ophthalmic Surg Lasers
1998,29:581-6
Editor,
In the discussion Bechmann and colleagues mention the results of Ehlers et al[1] and
compare them with the results of Whitacre et al[2] without regard for
generally accepted principles of interpretation.[3] Some biometrical
considerations will be found in the following.
In figure 4 in the paper by Ehlers et al the correlation coefficient between
the correction value and corneal thickness is 0.768...
Editor,
In the discussion Bechmann and colleagues mention the results of Ehlers et al[1] and
compare them with the results of Whitacre et al[2] without regard for
generally accepted principles of interpretation.[3] Some biometrical
considerations will be found in the following.
In figure 4 in the paper by Ehlers et al the correlation coefficient between
the correction value and corneal thickness is 0.768 at n=29. In the
comparable figure 2 of Whitacre et al no correlation coefficient is given
at n=15. This coefficient was calculated by us after digitalizing the data
points. It equals 0.51. According to Klemm[3] (page 97) the estimate of
regression is extremley unreliable and thus useless at r<_0.6. xmlns:study="urn:x-prefix:study" the="the" data="data" of="of" ehlers="ehlers" et="et" al="al" therefore="therefore" are="are" much="much" more="more" convincing="convincing" than="than" whitacre="whitacre" al.="al." this="this" fact="fact" does="does" not="not" reduce="reduce" merit="merit" whitacres="whitacres" study="study" which="which" brought="brought" problem="problem" corneal="corneal" influence="influence" on="on" tonometry="tonometry" to="to" our="our" attention.="attention." it="it" escaped="escaped" attention="attention" bechmann="bechmann" that="that" figure="figure" _4="_4" al1="al1" and="and" _2="_2" al2="al2" one="one" hand="hand" differ="differ" fundamentally="fundamentally" from="from" in="in" paper="paper" by="by" wolfs="wolfs" al4="al4" other="other" reports="reports" results="results" rotterdam="rotterdam" study:_="study:_" ordinate="ordinate" shows="shows" correction="correction" value="value" according="according" thickness="thickness" measurement="measurement" error="error" thickness.="thickness." these="these" two="two" ordinates="ordinates" sign="sign" show="show" result="result" subtraction="subtraction" intracamerally="intracamerally" measured="measured" iop="iop" applanation="applanation" values.="values." however="however" tonometry.="tonometry." is="is" a="a" fundamental="fundamental" difference="difference" absolutely="absolutely" forbids="forbids" comparison="comparison" same="same" breath.="breath." provide="provide" correlation="correlation" coefficient="coefficient" shown="shown" may="may" be="be" interpreted="interpreted" as="as" cloud="cloud" points.="points." we="we" have="have" similar="similar" calculated="calculated" r="0.17." case="case" concluded="concluded" estimate="estimate" regression="regression" playing="playing" with="with" figures="figures" only3page="only3page" _97.p="_97.p"/> In summary, the data of
Ehlers et al presently show the association of measurement error and
corneal thickness in the most convincing way.
Although Bechmann et al have (erroneously) seen a small influence of CCT
in IOP measurement in the literature they attribute an important part to
corneal thickness in the diagnosis and understanding of various types of
glaucoma. It can be concluded from the context that the authors treat
corneal thickness as a new quantity in the diagnosis of glaucoma-like
optic disk parameters. They have nicely shown different values of corneal
thickness in the various types of glaucoma. However, they do not believe
that corneal thickness influences applanation tonometry. Therefore, they
have to explain their findings in a more complicated way. A description of
this behaviour is given by the psychologist and philosopher Watzlawick[5] (page
67) who states that we prefer declaring undeniable facts (which are
inconsistent with our explanation) to be untrue or unreal instead of
fitting our explanation to these facts.
The application of biometric knowledge in judging the data Whitacre et al[2] and a reinterpretation of the figure 2 of the Rotterdam study[4] may fit
the opinion of the authors to the most likely explanation[6-8] that
corneal thickness influences the results in applanation tonometry to a
clinically relevant degree. And that recommends the application of OCT in
the diagnosis of glaucoma if available.
1. Ehlers N, Bramsen T, Sperling S. Applanation tonometry and
central corneal thickness. Acta Ophthalmol (Copenh) 1975;53:34-43.
2. Whitacre MM, Stein RA, Hassanein K. The effect of corneal
thickness on applanation tonometry. Am J Ophthalmol 1993;115:592-596.
3. Klemm PG. Keine Angst vor Biomathematik. Berlin: Ullstein Mosby, 1993.
4. Wolfs RC, Klaver CC, Vingerling JR, et al. Distribution of
central corneal thickness and its association with intraocular pressure:
The Rotterdam Study. Am J Ophthalmol 1997;123:767-772.
5. Watzlawick P. Wie wirklich ist die Wirklichkeit? München: Piper, 1976.
6. Bron AM, Creuzot-Garcher C, Goudeau-Boutillon S, et al. Falsely
elevated intraocular pressure due to increased central corneal thickness
[In Process Citation]. Graefes Arch Clin Exp Ophthalmol 1999;237:220-224.
7. Stodtmeister R. Applanation tonometry and correction according to
corneal thickness. Acta Ophthalmol Scand 1998;76:319-324.
8. Shah S, Chatterjee A, Mathai M, et al. Relationship between corneal
thickness and measured intraocular pressure in a general ophthalmology
clinic. Ophthalmology 1999;106:2154-2160.
Editor, This paper describes 9 consecutive patients suffering from
sagging of the lower eyelid due to facial palsy, in whom lifting of the
suborbicularis oculi fat (SOOF) was added to the usual treatment with the
lateral tarsal strip procedure and, if indicated, medical canthal
tightening. Based on observation of her results, the author concludes
that SOOF-lifting both supports the elevation of the low...
Editor, This paper describes 9 consecutive patients suffering from
sagging of the lower eyelid due to facial palsy, in whom lifting of the
suborbicularis oculi fat (SOOF) was added to the usual treatment with the
lateral tarsal strip procedure and, if indicated, medical canthal
tightening. Based on observation of her results, the author concludes
that SOOF-lifting both supports the elevation of the lower eyelid and
enhances the cosmetic results. However, the study offers no clear data on
postoperative lower eyelid height or any comparison of her results with
reported data on the tarsal strip procedure alone. Therefore, I feel that
the study offers insufficient evidence to support these conclusions.
Since the addition of SOOF-lifting to a relatively straightforward lateral
tarsal strip procedure is likely to enhance its morbidity (more
conjunctival chemosis, as stated by the author, possible damage to the
infraorbital nerve, more bleeding and infection), I would suggest that
routinely adding a SOOF-life to the tarsal strip procedure should be
postponed until the advantage of this addition has been demonstrated more
clearly, preferably in a randomized prospective series that quantifies the
lower eyelid position and that uses an independent observer for
qualitative comparison.
Editor, Trichiasis is a posterior misdirection of eyelashes. Due
to constant corneal irritation it can give rise to discomfort, recurrent
infection, corneal ulceration and pannus formation. Several modalities of
treatment exist which include epilation, electrolysis, cryotherapy and
argon laser thermoablation.[1] [2]
Argon laser offers the advantage of being a relatively simple, virtually
painless met...
Editor, Trichiasis is a posterior misdirection of eyelashes. Due
to constant corneal irritation it can give rise to discomfort, recurrent
infection, corneal ulceration and pannus formation. Several modalities of
treatment exist which include epilation, electrolysis, cryotherapy and
argon laser thermoablation.[1] [2]
Argon laser offers the advantage of being a relatively simple, virtually
painless method of destroying the eyelash follicle. It is especially
useful when there is a need to limit contiguous tissue inflammation and
destruction, e.g., ocular pemphigoid.[3] Argon laser can be precisely
applied to the follicle with or without topical anaesthesia. A beam size
of 50 micros, for a duration of 0.1 second and energy levels of 400 to 500
milliwatts is normally used in our clinic.
Thermoablation depends on the absorption of argon laser by pigment. In
our experience, patients with chronic trichiasis, who have undergone
repeated removal of eyelashes with other available methods, have pale
hypopigmented lashes which do not absorb sufficient laser energy. This
makes it difficult and sometimes impossible to get a result in spite of
increasing the energy levels. Recently, we have used a blue skin marker
pen to mark the base of the offending eyelash with the result that argon
laser is better absorbed by the blue pigment. Once there is initial
uptake subsequent shots down the lash root can be easily completed.
In conclusion, we have found the simple and inexpensive technique of
marking eyelash bases useful in increasing the efficacy of argon laser
photoepilation.
1. Bartley GB, Lowry JC. Argon laser treatment of trichiasis. Am J
Ophthalmol 1992;113:71-74.
2. Bartley GB, Bullock JC, Olsen TG, et al. An experimental study to
compare methods of eyelash albation. Ophthalmology 1987;94:1286-1289.
3. Sharif KW, Arafat AF, Wykes WC. The treatment of recurrent trichiasis
with argon laser photocoagulation. Eye 1991;5:591-595.
Editor, It is pleasing to see Tole et al[1] having success with
impression cytology (IC) in the diagnosis of ocular surface squamous
neoplasia (OSSN) and we thank the authors for their acknowledgment of our work.
We continue to use the small cellulose acetate strips because they offer greater sampling flexibility. However, the Biopore membrane could have practical advantages if samples are to be colle...
Editor, It is pleasing to see Tole et al[1] having success with
impression cytology (IC) in the diagnosis of ocular surface squamous
neoplasia (OSSN) and we thank the authors for their acknowledgment of our work.
We continue to use the small cellulose acetate strips because they offer greater sampling flexibility. However, the Biopore membrane could have practical advantages if samples are to be collected from a variety of locations and transported to the laboratory. We strongly recommend the use of the Papanicolaou stain when examining cytological preparations for this squamous neoplasm because the keratinized group offers the biggest challenge to diagnosis. Neither the Giemsa nor haematoxylin and eosin stains used by Tole et al are likely to be as helpful.
Tole et al. note that the accuracy of IC in their hands is very
similar to that quoted in our original publication and their results are also similar to our later report on a much larger group of intraepithelial and invasive histologically confirmed cases.[2] It seems reasonable to assume that both cellulose acetate strips and the Biopore membrane are equally efficient at sampling the ocular surface if the lesion is easily accessible.
The difficulty in interpretation of these specimens caused by the
paucity of literature relating to cytological criteria is noted by Tole et al. A recent publication on the cytomorphology of OSSN[3] may be helpful. It describes the cytological diversity seen in histologically confirmed impressions from 152 different patients including 23 with invasive SCC of the ocular surface.
GLENDA R NOLAN*,**
LAWRENCE W HIRST**
*Division of Anatomical Pathology and Cytopathology,
QHPS-RBHc, Royal Brisbane Hospital 4029, Australia.
**Division of Ophthalmology, Department of Surgery, The University of
Queensland, Brisbane, Australia.
1. Tole DM, McKelvie PA, Daniell M. Reliability of impression
cytology for the diagnosis of ocular surface neoplasia employing the
Biopore membrane. Br J Ophthalmol 2001;85:154-158.
2. Nolan GR, Hirst LW, Bancroft BJ. Impression cytology in the
identification of ocular surface squamous neoplasia: is it
accurate?[abstract] Invest Ophthalmol Vis Sci 1998;39(Suppl 543):2500.
3. Nolan GR, Hirst LW, Bancroft BJ. The cytomorphology of ocular surface squamous neoplasia by using impression cytology. Cancer (Cancer
Cytopathol) 2001;93:60-67.
Editor, We read with interest the article by Valmaggia et al[1] who
studied OKN in patients with macular degeneration. They noted
abnormalities of OKN gain only in patients with large central scotomas.
Therefore an intact macula seems not to be necessary for the generation of
OKN. This implicitly suggests an important role of the peripheral retina
in eliciting an OKN. In this context, it is interes...
Editor, We read with interest the article by Valmaggia et al[1] who
studied OKN in patients with macular degeneration. They noted
abnormalities of OKN gain only in patients with large central scotomas.
Therefore an intact macula seems not to be necessary for the generation of
OKN. This implicitly suggests an important role of the peripheral retina
in eliciting an OKN. In this context, it is interesting to note that we
observed an inversed OKN in some patients with defects of the central
visual field. An inversed OKN is an OKN with fast phases in the
direction opposite to the stimulus. The eyes in which an inversed OKN was
provoked more easily or at lower stimulus velocities had the largest
central field defects. It was a prerequisite to elicit an inversed OKN
that the attention was actively directed to the central field defect. Taking our results[2] and those of Valmaggia et al together, this would suggest that the abnormal OKN in central field defects could not only be due to the field defect itself, but could also be influenced by a remarkable property of the more
peripheral retina to induce an OKN in the inversed direction,
counteracting the OKN in the classical direction. In this central-peripheral interaction, we proposed an important role for the spatial-selective attention.[3] It would be very interesting to find a method to
monitor direction of attention simultaneously with OKN.
1. Valmaggia C, Charlier J, Gottlob I. Optokinetic nystagmus in patients
with central scotomas in age related macular degeneration. Br J
Ophthalmol 2001;85;169-172.
2. Crevits L, van Vliet AGM. Optokinetic nystagmus in patients with
defects of the central visual field. Eur Neurol 1986;25:454-457.
3. Crevits L, van Vliet AGM. Optokinetic nystagmus and spatial-selective
attention. An experimental study. Ophthalmologica 1991;202:105-108.
I have two points to make about this article:
1. Adhesion to the capsule works even during implantation of IOLs. As the acrylate material IOLs seem to have a higher adhesion tendency they require a lubricant viscoelastic material during rotation and positioning. This is why it is more difficult to rotate an acrylate IOL while using an AC maintainer and no viscoelastics. Silicone and PMMA IOLs do not...
The paper by El Mallah, et al. [1], reporting visual recovery in the amblyopes after visual loss in the non-amblyopic eye brings new evidence for visual system plasticity extending beyond what was considered the critical period. Our observation of two patients presented below further supports it and suggests plasticity may be pharmacologically enhanced.
A 22-year-old woman with strabismic amblyopia...
Dear Editor
We found that the reported incidence of approximately 1 per 2,000 (or 50 per 100,000) per year, and prevalence (54.5 per 100,000) of keratoconus reported by Bawazeer et al,[1] present some contradictions and formal imprecision.
Incidence is a dynamic morbidity rate, which indicates the number of new cases occurring during a specified period of time, over the population at risk in the same per...
Dear Editor
The recent article by Newsom et al.[1] on transpupillary thermotherapy (TTT) raises more questions than it is able to answer. Although TTT is definitely a method which seems to show a certain efficacy in occult choroidal neovascularization (CNV) and thus warrants further investigation, we must take issue with the authors' conclusions concerning its use in classic CNV.
The authors state tha...
Dear Editor
I thank Van den Bosch for his interest in my paper[1] on the role of the suborbicularis oculi fat (SOOF) lift in the rehabilitation of patients with chronic facial palsy. The aim of my paper was to describe the lateral tarsal strip (LTS)[2,3] in conjunction with a SOOF lift in the correction of lower eyelid "sag" or paralytic ectropion. The use of this procedure was confined to patients in whom, pre...
Editor,
In the discussion Bechmann and colleagues mention the results of Ehlers et al[1] and compare them with the results of Whitacre et al[2] without regard for generally accepted principles of interpretation.[3] Some biometrical considerations will be found in the following. In figure 4 in the paper by Ehlers et al the correlation coefficient between the correction value and corneal thickness is 0.768...
Editor,
This paper describes 9 consecutive patients suffering from sagging of the lower eyelid due to facial palsy, in whom lifting of the suborbicularis oculi fat (SOOF) was added to the usual treatment with the lateral tarsal strip procedure and, if indicated, medical canthal tightening. Based on observation of her results, the author concludes that SOOF-lifting both supports the elevation of the low...
Editor,
Trichiasis is a posterior misdirection of eyelashes. Due to constant corneal irritation it can give rise to discomfort, recurrent infection, corneal ulceration and pannus formation. Several modalities of treatment exist which include epilation, electrolysis, cryotherapy and argon laser thermoablation.[1] [2] Argon laser offers the advantage of being a relatively simple, virtually painless met...
Editor,
It is pleasing to see Tole et al[1] having success with impression cytology (IC) in the diagnosis of ocular surface squamous neoplasia (OSSN) and we thank the authors for their acknowledgment of our work.
We continue to use the small cellulose acetate strips because they offer greater sampling flexibility. However, the Biopore membrane could have practical advantages if samples are to be colle...
Editor,
We read with interest the article by Valmaggia et al[1] who studied OKN in patients with macular degeneration. They noted abnormalities of OKN gain only in patients with large central scotomas. Therefore an intact macula seems not to be necessary for the generation of OKN. This implicitly suggests an important role of the peripheral retina in eliciting an OKN. In this context, it is interes...
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