We read with interest the article by J A Montero and J M Ruiz-Moreno
on ‘Optical coherence tomography (OCT) characterization of idiopathic
central serous chorioretinopathy (ICSC)’.[1] We agree that OCT may offer a
new approach to the staging and knowledge of ICSC, and may help the
understanding of the mechanisms of the disease.
In our personal experience
of OCT evaluation of 56 eyes we observ...
We read with interest the article by J A Montero and J M Ruiz-Moreno
on ‘Optical coherence tomography (OCT) characterization of idiopathic
central serous chorioretinopathy (ICSC)’.[1] We agree that OCT may offer a
new approach to the staging and knowledge of ICSC, and may help the
understanding of the mechanisms of the disease.
In our personal experience
of OCT evaluation of 56 eyes we observed that with-in first two weeks of
onset of symptoms the OCT showed a neurosensory detachment of varied
extent and height in all the eyes which authors refer as optically empty
vaulted area under the neurosensory retina. A clearly demarcated dome
shaped retinal pigment epithelium detachment (RPED) was seen in 40 eyes
where as clinically it could be picked up in 24 eyes-only. Careful
analysis of OCT scan revealed characteristic small bulges similar to what
authors have described were seen protruding from RPE, in 16 eyes and it
related to leaking spots on angiography. We also observed that pick up
rate of these small bulges was enhanced if the OCT was performed
immediately following fluorescein angiography.
OCT performed in the resolving stages of the disease showed either a
complete resolution or a partial resolution of the neurosensory detachment
with persisting RPEDs along with neurosensory thinning. Few eyes showed
decreased height of RPEDs suggestive of collapsing RPEDs.
Thus, we share the same view with the authors that OCT is a useful tool
for diagnosis, monitoring and follow-up of patients with ICSC and offers
valuable information for establishing a new classification for ICSC.
References
1. Montero JA, Ruiz-Moreno JM. Optical coherence tomography
characterization of idiopathic central serous chorioretinopathy. Br J
Ophthalmol 2005;89:562-564.
We read with keen interest the recently published article by Shields
et al.[1] Cholesterol lowering agents may indeed evolve as a
physiological and non-invasive therapeutic modality for this cosmetically
disfiguring entity. We would like to raise a few pertinent issues related
to this article.
We would like to draw your attention to the fact that there is a
marked difference in the quali...
We read with keen interest the recently published article by Shields
et al.[1] Cholesterol lowering agents may indeed evolve as a
physiological and non-invasive therapeutic modality for this cosmetically
disfiguring entity. We would like to raise a few pertinent issues related
to this article.
We would like to draw your attention to the fact that there is a
marked difference in the quality of the pre and post-treatment photographs
of the patient. The pre-treatment picture is grossly underexposed as
compared to the post-treatment one, which is overexposed. In an
overexposed photograph, the patient’s skin complexion appears rather
light, thereby making a yellowish lesion such as a Xanthelasma less
prominent in contrast, and vice versa. Therefore it would be incorrect to
say that the Xanthelasmas have completely resolved after treatment. We
would like to reiterate that extremely stringent standards of clinical
photography and colour reproduction should be adhered to in cosmetic and
ophthalmic plastic surgery for the images to be comparable, credible and
scientifically relevant.[2]
There are various other factors that may contribute to a serial
reduction in prominence of the lesion and should be taken into
consideration. Xanthelasma lesions are known to enlarge and coalesce over
time. This makes the margins indistinct and the lesion could appear to
merge with the surrounding skin, thereby changing its characteristics from
a well demarcated to a somewhat diffuse entity. As there is a long
interval of ten years between the two assessments, one also has to take
into account the changes in texture and pigmentation of the skin that
invariably occur with aging. The surrounding skin pigmentation could
reduce with advancing age due to a decrease in melanocyte density [3],
possible hormonal influences, and a presumed reduction in outdoor
activities leading to lesser exposure to sunlight. Moreover, there is
wrinkling and change in texture of the eyelid skin due to loss of
elasticity, resilience and flexibility of the dermis and thinning of the
epidermis associated with aging.[4] These changes, which are expected in
the patient reported by the authors have to be factored in while
objectively evaluating such a case as they could play a significant role
in the reduction in prominence of the Xanthelasma lesion over time. Once
these concerns are suitably addressed, one could appreciate this article
in a proper perspective.
References
1. Shields CL, Mashayekhi A, Shields JA, Racciato P. Disappearance of eyelid xanthelasma following oral simvastatin (Zocor). Br J Ophthalmol. 2005 May;89(5):639-40.
2. Bajaj MS, Pushker N, Mahindrakar A, Balasubramanya R. Standardised clinical photography in ophthalmic plastic surgery. Br J Ophthalmol. 2003 Mar;87(3):375-6.
3. Wulf HC, Sandby-Moller J, Kobayasi T, Gniadecki R. Skin aging and natural photoprotection. Micron. 2004;35(3):185-91.
4. Giacomoni PU, Rein G. A mechanistic model for the aging of human skin. Micron. 2004;35(3):179-84.
We read with great interest the article by McCarthy et al. ”Use of eye
care services by people with diabetes: the Melbourne Visual Impairment
Project”.[1]
We observed similar eyecare practices by rural and urban diabetics in
a diabetic retinopathy-screening program.
4,517 rural and 3,199 urban diabetics above 30 years of age attended 51
diabetic retinopathy-screening camps conducted between Ju...
We read with great interest the article by McCarthy et al. ”Use of eye
care services by people with diabetes: the Melbourne Visual Impairment
Project”.[1]
We observed similar eyecare practices by rural and urban diabetics in
a diabetic retinopathy-screening program.
4,517 rural and 3,199 urban diabetics above 30 years of age attended 51
diabetic retinopathy-screening camps conducted between June 2003 and
September 2004 in three districts of south India. The mean duration of
diabetes mellitus was 7 years in the rural areas and 4 years in the urban
population. Prior to dilated fundus examination a detailed medical
history was elicited which included question regarding previous eye
examination status after diagnosis of diabetes.
The results showed that around 63% (n = 2168) of individuals in the
rural areas and 75% (n=2399) in the urban areas never had their eye
examined for diabetic retinopathy. When we analyzed the eye examination
status among the sight threatening retinopathy (PDR, Severe NPDR, CSME
/combination) 45% (n= 139) of rural and 50% (n=74) of urban diabetics never
had a fundus evaluation before.
Similarly Moss et al. [2] found that over 70% of both young and old onset
diabetics in Wisconsin reported not having an eye examination in the
previous year because they had no eye problems. Namperumalswamy et al. [3]
reported that only 6.8% of diabetics underwent dilated eye examination
before in their diabetic retinopathy-screening model. Unfortunately the
trend of regular dilated fundus examinations by diabetics was not observed
in studies done in both developed countries as well as developing
countries.
These results clearly show the need for an intensive awareness
campaign with a key home message “All diabetics need dilated eye
examination once a year” in both developed and developing countries.
References
1.Catherine A McCarty,a Conrad W Lloyd-Smith,a Sharon E Lee et al. Use
of eye care services by people with diabetes: the Melbourne Visual
Impairment Project.Br J Ophthalmol 1998;82:410-414.
2.Moss SE, Klein R, Klein BEK: Factors associated with having eye
examinations in persons with diabetes. Arch Fam Med 1995; 4:529-534.
3. Namperumalsamy P,Pravin K Nirmalan,Kim Ramasamy, et al.
Developing a screening program to detect sight- threatening diabetic
retinopathyinSouthIndia. Diabetes Care 2003; 26:1831-1835.
We are pleased at the interest shown by Dr. Stapleton and colleagues in our
work [1] and we note their endorsement of our approach in adopting a clinical
severity classification system for the assessment of contact lens associated
keratitis.
Dr. Stapleton and colleagues have expressed concern at the high incidence of
severe keratitis that we reported for hydrogel extended wear lenses. They
sugg...
We are pleased at the interest shown by Dr. Stapleton and colleagues in our
work [1] and we note their endorsement of our approach in adopting a clinical
severity classification system for the assessment of contact lens associated
keratitis.
Dr. Stapleton and colleagues have expressed concern at the high incidence of
severe keratitis that we reported for hydrogel extended wear lenses. They
suggested that our claim that this result could be attributed to a higher
capture rate of cases (due to our single-centre methodology) is flawed
because, if this were true, the incidence rate we reported for other lens types
should also be higher than those reported previously. In support of their
argument, Dr. Stapleton and co-workers presented data from only a selected
range of previous studies. However, our reported incidence rates are typically
higher than those reported previously for all categories of lens types.
For example, the incidence values reported in our study for daily wear rigid,
daily wear hydrogel and extended wear hydrogel were 2.6, 1.8 and 4.8 times
greater than those reported by Cheng et al. [2], respectively.
In relation to the specific case of data for hydrogel extended wear lenses
(Figure 1) it is clear that the incidence figure we report is of the same order of
magnitude as that reported by Poggio and Abelson [3] and Holden et al. [4]. It
is noteworthy that the higher values reported by Poggio and Abelson [3],
Holden et al. [4], and ourselves are derived from studies in which case capture
was the responsibility of a small number of centres (eight centres, two
centres and one centre, respectively), whereas the lower values reported by
other authors [2,5-7] were derived from studies that typically involved
hundreds of reporting centres. This observation lends support to our
supposition that the use of a limited number of reporting centres will result in
higher, and necessarily more accurate, estimates of incidence, albeit with
larger statistical confidence intervals. We would suggest that the recently-
published estimate of Holden et al. [4] (57.9 cases per 10,000 wearers per
year, 95% confidence interval 21.3 – 126) is likely to be the most accurate
incidence value for severe keratitis with hydrogel extended wear contact
lenses, as this is based on the largest prospective cohort study yet published;
an approach which virtually ensures total case capture.
Figure 1. Published annualised incidence rates for presumed microbial
keratitis in extended wear hydrogel lens use from population based
studies using more than 200 report centres [2,5-7] (black circles)
and less than 10 report centres [1,3,4] (white circles). Vertical
lines show 95% confidence intervals.
Notwithstanding the arguments presented above, we agree with the general
sentiment expressed by Dr. Stapleton and colleagues of the desire to
reconcile the results of various studies addressing the question of contact
lens safety. A key factor in our own study was the criteria adopted to
differentiate between non-severe and severe keratitis. The use of different
criteria is likely to result in different incidence values between studies.
Indeed, this is the outcome of a separate analysis which we have conducted
and are in the process of preparing for publication.
Attention has been drawn to the ‘indirect’ methodology for determining the
incidence denominator in our study. It is of course the case that all
methodologies that have been used to determine information about the
control population in contact lens incidence studies (with the exception of
Holden et al. [4]) have been indirect. For example, Cheng et al. [2] and Poggio
et al. [5] estimated the denominator using telephone surveys. Such techniques
can also be problematic [8].
Dr. Stapleton and colleagues criticised our methodology as being likely to
over-estimate the penetrance of new modalities such as silicone hydrogel
lens use and under-estimate the penetrance of modalities such as rigid gas
permeable lenses. They appear to have assumed that our estimate of the
number of wearers of each lens type was determined from prescribing data.
While others, such as Radford, Minassian and Dart [9] have previously
adopted this approach, we agree that this would result in over- and under-
estimations of lens usage. Contrary to the assertion of Dr. Stapleton and co-
workers, we used lens sales data for 2003 (the year our survey was
conducted) which gives a precise estimate of the number of lens wearers.
The model which underpins these estimates has arisen from a three year
collaboration between one of us (PBM) and the UK Association of Contact Lens
Manufacturers and this approach has been previously validated as an accurate
method for predicting the number of wearers of various contact lens type
[10]. The use of prescribing data in our study was confined to establishing
the ratio of lenses worn on a daily vs. extended wear basis. This information
has been collected on an annual basis over the past nine years and in that
way we gained an accurate estimate of lens wear modalities in the UK during
the time of the survey.
Dr. Stapleton and colleagues challenge our assumption that the prevalence of
contact lens usage in the catchment population of the Royal Eye Hospital in
Manchester is essentially the same as that throughout the UK. The
appropriateness of their suggestion of extrapolating the data from Market
Opinion Research International (MORI) on overall lens penetrance (as cited by
Radford, Minassian and Dart [9]) to our results is unclear; however, assuming
that it is sound, we agree that this could impact on our data by uniformly
raising or lowering our estimates of incidence to some extent. Nevertheless,
we are unaware of any evidence of regional differences of usage between
different lens types.
We reject the assertion of Dr. Stapleton and co-workers that the use of the
chi-square test for comparing estimates of incidence for lens types is
unjustified, whereas citing 95% confidence intervals is preferred. As the
underlying assumption of both of these approaches is that one has accurate
numbers of cases and controls, it is contradictory to advocate only one of
these approaches. We are confident that our estimates of cases and controls
are sufficiently robust to be able to apply the chi-square test. This chi-
square approach was adopted by Radford, Minassian and Dart [9] in coming
to their conclusion that the incidence of Acanthamoeba keratitis is lower in
users of daily disposable lenses versus users of other lens types.
Dr. Stapleton and colleagues cited the overlap of 95% confidence intervals for
the incidence of severe keratitis in extended wear hydrogel lenses and
extended wear silicone hydrogel lenses as undermining our assertion that
these incidence values are significantly different. However, the correct
application of 95% confidence intervals for comparative purposes is to
determine whether the estimate of incidence for one lens types falls within
the 95% confidence interval for the other lens type, and vice versa. In our
study, the incidence of severe keratitis for extended wear hydrogel lenses
(96.4 cases per 10,000 wearers per year) falls outside the 95% confidence
interval for the incidence of severe keratitis for extended wear silicone
hydrogel lenses (6.7 – 58.0); conversely, the incidence of severe keratitis for
extended wear silicone hydrogel lenses (19.8) falls outside the 95%
confidence interval for the incidence of severe keratitis for extended wear
hydrogel lenses (37.5 – 245.2). This confirms the chi-square result reported
in our paper of a significant difference between these two groups, a finding
which is consistent with predictions of reduced rates of severe keratitis with
silicone hydrogels lenses based on reports of worldwide cases of lens-related
infections [11] and the general clinical performance with this lens type
[12].
In conclusion, we feel that our paper presents a novel, robust and clinically-
meaningful portrayal of the risks associated with contemporary contact
lenses. We are confident that our methodological and statistical approaches
are sound, and we believe that the criticisms of Dr. Stapleton and colleagues
are largely unfounded. We are aware that other studies of the incidence of
contact lens related keratitis are currently underway, and we look forward
with interest to the outcome of these studies inasmuch as they will assist the
contact lens community in arriving at a more comprehensive picture of the
relative safety of different contact lens types.
Yours faithfully,
Philip B Morgan1 Nathan Efron1 Elizabeth A Hill1 Mathew K Raynor2 Mark A Whiting2 Andrew B Tullo2
1 Eurolens Research, The University of Manchester, Manchester, UK
2 Royal Eye Hospital, Manchester, UK
References
1. Morgan PB, Efron N, Hill EA,at al. Incidence of keratitis of varying severity
among contact lens wearers. Br J Ophthalmol 2005; 89:430-436.
2. Cheng KH, Leung SL, Hoekman HW, et al. Incidence of contact-lens-
associated microbial keratitis and its related morbidity. Lancet 1999;354:
181-185.
3. Poggio EC and Abelson M. Complications and symptoms in disposable
extended wear lenses compared with conventional soft daily wear and soft
extended wear lenses. Contact Lens Assoc Ophthalmol J 1993; 19:
31-39.
4. Holden BA, Sankaridurg PR, Sweeney DF, et al. Microbial keratitis in
prospective studies of extended wear with disposable hydrogel contact
lenses. Cornea 2005; 24: 156-161.
5. Poggio EC, Glynn RJ, Schein OD, et al. The incidence of ulcerative keratitis
among users of daily-wear and extended-wear soft contact lenses. N Engl J
Med 1989;321: 779-783.
6. Nilsson SE and Montan PG. The hospitalized cases of contact lens induced
keratitis in Sweden and their relation to lens type and wear schedule: results
of a three-year retrospective study. Contact Lens Assoc Ophthalmol J 1994;
20: 97-101.
7. Lam DS, Houang E, Fan DS, et al. Incidence and risk factors for microbial
keratitis in Hong Kong: comparison with Europe and North America. Eye
2002; 16: 608-618.
8. Aquilino WS. Telephone versus face-to-face interviewing for household
drug use surveys. Int J Addict 1992; 27: 71-91.
9. Radford CF, Minassian DC, and Dart JK. Acanthamoeba keratitis in England
and Wales: incidence, outcome, and risk factors. Br J Ophthalmol 2002; 86:
536-542.
10. Morgan PB. A healthcheck on the UK contact lens market. Optician 2002;
223 (5854): 14-16.<
11. Holden BA, Sweeney DF, Sankaridurg PR, Carnt N, Edwards K, Stretton S,
Stapleton F. Microbial keratitis and vision loss with contact lenses. Eye
Contact Lens 2003; 29: S131-4.
12. Covey M, Sweeney DF, Terry R, Sankaridurg PR, Holden BA. Hypoxic
effects on the anterior eye of high-Dk soft contact lens wearers are
negligible. Optom Vis Sci 2001; 78: 95-99.
In “Endophthalmitis associated with the Ahmed glaucoma valve
implant”[1], we can see the same predominant causative bacteria
(Haemophilus and Streptococcus) that we have been seeing in other series
of delayed onset endophthalmitis after glaucoma surgery since Mandelbaum
et al. series.[2] This time [1], eight out of nine endophthalmitis had a
delayed onset too, and two risk factors for endophthalmitis...
In “Endophthalmitis associated with the Ahmed glaucoma valve
implant”[1], we can see the same predominant causative bacteria
(Haemophilus and Streptococcus) that we have been seeing in other series
of delayed onset endophthalmitis after glaucoma surgery since Mandelbaum
et al. series.[2] This time [1], eight out of nine endophthalmitis had a
delayed onset too, and two risk factors for endophthalmitis (younger age
and conjunctival erosion over the tube) are significant. However, a
question still remains unanswered: Why do other bacteria, which are more
frequent on the conjunctiva, not cause this delayed endophthalmitis so
often?
Last year, we described [3] the fact that the frequency of Haemophilus and
Streptococcus on the conjunctiva of patients undergoing cataract surgery
(part of them having coexisting glaucoma) presented a seasonal pattern,
being more frequent when the average monthly temperature oscillates
between 6º-14ºC for Haemophilus, and 10º-18º for Streptococcus. A seasonal
pattern was described for conjunctivitis due to Haemophilus Influenzae and
Streptococcus Pneumoniae in London.[4] It seems as if the presence of
these bacteria depended on climatic factors. For instance, it has been
demonstrated that most Streptococcus Pneumoniae isolated in nasal carriers
disappears spontaneously, without treatment, in a few weeks.[5]
In case climatic factors could be another risk factor for delayed
onset endophthalmitis after glaucoma surgery, I would like to ask Dr. Al-
Torbak et al. [1] if the onset of their endophthalmitis due to Haemophilus
and Streptococcus took place around a particular part of the year and, if
so, what were the average monthly temperature and relative humidity in
this period, if possible.
Author affiliation
Elisa Fernández Rubio
Ophthalmic Institute Laboratory
Gregorio Marañón
University General Hospital
Madrid, Spain
Correspondence to:
Dra. Elisa Fernández Rubio
Instituto Oftálmico
Hospital General Universitario Gregorio Marañón. C/ General Arrando, 17.
Madrid 28010. SPAIN
mfernandezr.hghgm{at}salud.madrid.org The author declares do not have competing financial interests.
References
1. Al-Torbak AA, Al-Shahwan S, Al-Jadaan I, et al. Endophthalmitis
associated with the Ahmed glaucoma valve implant. Br J Ophthalmol
2005;89:454-458.
2. Mandelbaum S, Forster RK, Gelender H, et al. Late onset endophthalmitis
associated with filtering blebs. Ophthalmology 1985;92:964-972.
3. Rubio EF. Climatic influence on conjunctival bacteria of patients
undergoing cataract surgery. Eye 2004;18:778-784.
4. Jones BR, Andrews BE, Henderson WG, et al. The pattern of
conjunctivitis at Moorfields during 1956. Trans Ophthalmol Soc UK
1957;77:291-305.
5. Ekdahl K, Ahlinder I, Hansson HB, Melander E, Molstad S,
Soderstrom M,
et al. Duration of nasopharyngeal carriage of penicillin-resistant
Streptococcus pneumoniae: experiences from the South Swedish
Pneumococcal
Intervention Project. Clin Infect Dis 1997;25:1113-1117.
I would like to congratulate the author for this interesting manuscript.
Our ability to find the information we seek on the Internet is a
function of how precise our queries are and how effectively we use search
services. Poor queries return poor results; good queries return great
results. Contrary to the hype surrounding "intelligent agents" and
"artificial intelligence," the fact remains...
I would like to congratulate the author for this interesting manuscript.
Our ability to find the information we seek on the Internet is a
function of how precise our queries are and how effectively we use search
services. Poor queries return poor results; good queries return great
results. Contrary to the hype surrounding "intelligent agents" and
"artificial intelligence," the fact remains that search results are only
as good as the query you pose and how you search. There is no silver
bullet.
Of the keywords used in the study namely "retinopathy of
prematurity", "ROP", "premature eye" and "premature retina", which key word
provided good quality information both technically and quality wise?
Based on this study will it be possible to suggest possible, or the
best, keyword/s which will yield good quality and highly specific information
for ROP?
What is the reason to pick only the first 30 sites? does it have
anything to do with the specificity of the keyword? Like the first 30
sites displayed being highly specific!
The following are some links to search tips that you will find very
useful.
We read with interest Zia et al.’s article titled "Only rarely seen in
dreams - visual experiences during cataract surgery" which highlights a
professional artist’s and a poet’s respective renditions of their visual
experiences during phacoemulsification and intraocular lens implantation
under local anaesthesia.[1] While it is unclear from the report whether
the artist’s elaborate drawing resembling...
We read with interest Zia et al.’s article titled "Only rarely seen in
dreams - visual experiences during cataract surgery" which highlights a
professional artist’s and a poet’s respective renditions of their visual
experiences during phacoemulsification and intraocular lens implantation
under local anaesthesia.[1] While it is unclear from the report whether
the artist’s elaborate drawing resembling a "colourful monkey" was
associated with a pleasant or frightening visual experience, it appears
from the poem that the poet’s visual experience was most probably pleasant
and delightful.
We have previously reported that the visual experience during
cataract surgery under local anaesthesia can be frightening in up to 16.2%
of patients.[2-8] The anxiety that may result from the
intraoperative visual experience is clinically significant because it may
cause patients to become uncooperative during the procedure and trigger a
sympathetic stress response. This may result in hypertension, tachycardia,
ischaemic strain on the heart, hyperventilation and acute panic attacks.
These stress responses are particularly undesirable in cataract patients
who are often elderly, with systemic co-morbidities such as hypertension
and ischaemic heart disease.[2,9] The frightening experience may also
lower patients’ satisfaction with the surgery.[10-11]
The poet’s experience reported by Zia et al reminds us that the
intraoperative visual experience during cataract surgery can be pleasant
to some patients.[1] In fact, our experience has shown that the majority
of patients find their visual experiences pleasant and in some cases, the
visual experience actually increases their satisfaction with the surgery.
In a recently reported randomised controlled trial conducted in India
involving 304 patients who underwent phacoemulsification under either
topical anaesthesia (TA) or retrobulbar anaesthesia (RA), the visual
experience was reported by 106 out of 154 (68.8%) TA and 102 out of 150
(68%) RA patients to be pleasant and by 47 (30.5%) TA and 46 (30.7%) RA
patients to be unpleasant.[12] In a separate unpublished study conducted
in Singapore, 8 of 98 patients (8.2%) who had phacoemulsification under TA
reported that their satisfaction with the surgery increased because of
their visual experiences, whereas only 2 patients (2.0%) experienced a
decrease in satisfaction. The remaining 88 patients (89.8%) reported that
their visual experience did not affect their satisfaction with the
surgery. Some of the patients who found their visual experiences pleasant
commented on the "fantastic colours" that they experienced. In another
similar study on patients who had cataract surgery under RA, 9 of 152
patients (5.9%) experienced an increase in satisfaction, whereas 5
patients (3.3%) felt that their satisfaction had decreased as a result of
the visual experiences and the remaining 138 patients (90.8%) experienced
no change in their satisfaction.
An additional observation is from videotaped interviews conducted by
one of us (CMK) with several leading ophthalmic anaesthesia providers in
the United States who had cataract surgery under local anaesthesia
themselves. The video recordings were made during the annual scientific
meeting of the Ophthalmic Anaesthesia Society held in Chicago in October
2004. The videos clearly showed they reported seeing pleasant and
beautiful images during their surgery.
In summary, patients may experience pleasant or unpleasant visual
sensations during cataract surgery under local anaesthesia. Further
investigation is warranted to help ascertain how we can reduce the
possibility of the experience being unpleasant or frightening.
References
1. Zia R, Schlichtenbrede FC, Greaves B, Saeed MU. "Only rarely seen
in dreams" - visual experiences during cataract surgery. Br J Ophthalmol
2005;89:247-8.
2. Au Eong KG. 6th Yahya Cohen lecture: visual experience during
cataract surgery. Ann Acad Med Singapore 2002;31:666-74.
3. Prasad N, Kumar CM, Patil BB, Dowd TC. Subjective visual
experience during phacoemulsification cataract surgery under sub-Tenon's
block. Eye 2003;17:407-9.
4. Au Eong KG. The Royal College of Ophthalmologists cataract
surgery guidelines: what can patients see with their operated eye during
cataract surgery? Eye 2002;16:109-10.
5. Au Eong KG, Lim TH, Lee HM, Yong VSH. Subjective visual
experience during phacoemulsification and intraocular lens implantation
using retrobulbar anaesthesia. J Cataract Refract Surg 2000;26:842-6.
6. Au Eong KG, Low CH, Heng WJ, Aung T, Lim ATH, Ho SH et al.
Subjective visual experience during phacoemulsification and intraocular
lens implantation under topical anaesthesia. Ophthalmology 2000;107:248-
50.
7. Au Eong KG, Lee HM, Lim ATH, Voon LW, Yong VSH. Subjective visual
experience during extracapsular cataract extraction and intraocular lens
implantation under retrobulbar anaesthesia. Eye 1999;13:325-8.
8. Tranos PG, Wickremasinghe SS, Sinclair N, Foster PJ, Asaria R,
Harris ML et al. Visual perception during phacoemulsification surgery
under topical and regional anaesthesia. Acta Ophthalmol Scand 2003;81:118-
22.
9. Tan CSH, Rengaraj V, Au Eong KG. Visual experiences of cataract
surgery. J Cataract Refract Surg 2003;29:1453-4.
10. Leo SW, Au Eong KG. Comments on anaesthesia for cataract
surgery. J Cataract Refract Surg 2003;29:633-5.
11. Leo SW, Au Eong KG, Rengaraj V, Radhakrishnan M. The
Misericordia Health Centre cataract comfort study. Can J Ophthalmol
2003;38:23-4.
12. Rengaraj V, Radhakrishnan M, Au Eong KG, Saw SM, Srinivasan A,
Mathew J et al. Visual experience during phacoemulsification under topical
versus retrobulbar anaesthesia: results of a prospective, randomised,
controlled, trial. Am J Ophthalmol 2004;138:641-8.
I am pleased to have these very
important questions on our study.
In our patients with normal tension
glaucoma, some patients
presented with decreased vision which was consistent with the
typical glaucomatous optic nerve head changes and with the
glaucomatous nerve fiber layer defects detected by visual
field testing. In addition, none of them complained of
decreased color vision. We did no...
I am pleased to have these very
important questions on our study.
In our patients with normal tension
glaucoma, some patients
presented with decreased vision which was consistent with the
typical glaucomatous optic nerve head changes and with the
glaucomatous nerve fiber layer defects detected by visual
field testing. In addition, none of them complained of
decreased color vision. We did not notice any pallor of the
temporal neuroretinal rim on the side of the compressed
optic nerve. We also did not notice any difference in the
configuration of the cupping in eyes with and without optic
nerve compression.
Regarding the nine patients with unilateral optic nerve
compression, as mentioned in the discussion, additional
studies with long-term follow-up will be necessary to
determine how optic nerve compression is contributing to
the optic neuropathy in NTG and the prognosis of NTG.
With interest we read the recent retrospective case-control study on
the causal interaction between endophthalmitis and intraocular lens (IOL)
biomaterials by Wong and Chee [1]. They concluded that "…silicone (when
compared with PMMA or acrylic IOL) … was independently associated with
acute endophthalmitis". We believe that a few comments have to be
addressed to clarify the findings for their read...
With interest we read the recent retrospective case-control study on
the causal interaction between endophthalmitis and intraocular lens (IOL)
biomaterials by Wong and Chee [1]. They concluded that "…silicone (when
compared with PMMA or acrylic IOL) … was independently associated with
acute endophthalmitis". We believe that a few comments have to be
addressed to clarify the findings for their readers.
Obviously bacterial adhesion properties vary widely with IOL-specific
details. The information about the IOL type used consequently needs to be
specified for every single IOL used in any individual case in order to
allow a complete risk analysis. Indeed, among biomaterials of the same
type, different IOLs that exist on the market do not have the same
properties (rate of hydrophilicity, electric charge, and composition).
This specific issue, however, has only roughly been addressed by the
authors. Manufacturer and model number were not specified on a single case
basis, and the number of study eyes is limited (136 eyes, 34 cases and 102
controls). Whether the acrylic IOL used was always hydrophobic (MA60BM
from Alcon, mentioned in the Methods section), or sometimes hydrophilic,
if the PMMA IOLs were only provided by Pharmacia, and whether the silicone
IOLs were always SI40NB, is of significant relevance for the study
results. The otherwise similar SI30NB silicone IOL from Allergan, for
example, has polypropylene haptics, this biomaterial being a recognized
risk factor for the development of postoperative endophthalmitis [2].
Consequently, different IOL types could provide a significant bias to the
study of Wong and Chee. Applying the results of this study to clinical
practice without additional information may therefore be questionable.
Secondly, the comparison of IOL type was conducted between cases and
operating-date matched controls, but not between cases and the whole
population having obtained the same IOL type, as done by Montan et al. [3,4]. Indeed, the 2 studies of Montan et al., which are still deemed the index
ones, compared the number of each IOL type in the endophthalmitis cases to
the identical inserted in the whole population operated on during the
study period. Out of these, Montan et al. selected, in a random fashion,
control subjects to obtain a comparison of the patient history and
surgical procedure variables, since possible variables are too numerous to
be extracted from the whole population. The selection of the control group
not according to the IOL type but to the day of surgery could also have
biased the results by Wong and Chee which are contradictory to the
literature about silicone and PMMA [3,4] and about silicone and hydrophobic
acrylic [5]. Lastly, Wong and Chee published during the same period another
article, in which the whole population was assessed [6]. In the whole
population comparison6 they found that phacoemulsification technique is
associated with a higher risk of endophthalmitis compared to extracapsular
cataract extraction, whereas they did not succeed to find any
corresponding difference in the present case-control study [1], providing
further evidence that this latter may be prone to a selection bias.
We appreciate the efforts of this study, and our comments are not
intended to lower the merit of this study, but interpreting the results
might be done with care unless the information essential for
interpretation of the results has been added.
References
1. Wong TY, Chee SP: Risk factors of acute endophthalmitis after
cataract extraction: a case-control study in Asian eyes. Br J Ophthalmol.
2004; 88: 29-31.
2. Bainbridge JW, Teimory M, Tabandeh H, et al.: Intraocular lens
implants and risk of endophthalmitis. Br J Ophthalmol. 1998; 82: 1312-5.
3. Montan PG, Koranyi G, Setterquist HE, et al.: Endophthalmitis
after cataract surgery: risk factors relating to technique and events of
the operation and patient history: a retrospective case-control study.
Ophthalmology. 1998; 105: 2171-7.
4. Montan P, Lundstrom M, Stenevi U, Thorburn W: Endophthalmitis
following cataract surgery in Sweden.The 1998 national prospective survey.
Acta Ophthalmol Scand. 2002; 80: 258-61.
5. Nagaki Y, Hayasaka S, Kadoi C, et al.: Bacterial endophthalmitis
after small-incision cataract surgery. effect of incision placement and
intraocular lens type. J Cataract Refract Surg. 2003; 29: 20-6.
6. Wong TY, Chee SP: The epidemiology of acute endophthalmitis after
cataract surgery in an Asian population. Ophthalmology. 2004; 111: 699-
705.
We read with great interest the article by Ruschen et al. comparing
patient satisfaction during cataract surgery with sub-Tenon’s block (STB)
versus topical anaesthesia (TOP) [1]. The authors concluded that in the
setting of day case cataract surgery, patients reported significantly
higher satisfaction scores with STB than TOP.
We would like to raise two issues for discussion. Firstly, th...
We read with great interest the article by Ruschen et al. comparing
patient satisfaction during cataract surgery with sub-Tenon’s block (STB)
versus topical anaesthesia (TOP) [1]. The authors concluded that in the
setting of day case cataract surgery, patients reported significantly
higher satisfaction scores with STB than TOP.
We would like to raise two issues for discussion. Firstly, the lower
satisfaction score in the TOP group may only reflect a suboptimal TOP that
was given in the current study and may not be generalisable to other forms
of TOP. In our experience, lignocaine gel (lidocaine hydrochloride 2%,
AstraZeneca? Sweden) produces significantly better anaesthetic effects
than local anaesthetic eyedrops. Lignocaine gel has been previously shown
to be an effective [2,3] and possibly a more superior [4,5] anaesthetic agent in
cataract surgery, as well as giving better patient cooperation with less
intra-operative supplement [5]. To further evaluate the apparent lower
satisfaction scores with TOP than STB, we would be grateful if the authors
could provide the details on their TOP anaesthetic procedure, for example
how long before the actual surgery were proxymetacaine and amethocaine
given and whether supplementary anaesthetic eyedrops were allowed during
the surgery?
Secondly, even though the median satisfaction score in the TOP group
was significantly lower than that of the STB group, there was a much
larger variation in the TOP group (Figure 1). This would imply some
patients were satisfied whilst some were dissatisfied. We certainly
believe not all patients can tolerate TOP and it would be highly desirable
for cataract surgeons to identify the latter group pre-operatively. Were
there any specific characteristics in this group showing such
dissatisfaction? Moreover, we noted that there were more females (12 out
of 14 patients) in the TOP group, compared to the STB group (5 out of 14
patients). This difference was statistically significant (p = 0.018,
Fisher’s exact test). We recognise that randomisation had been implemented
in the present study and any significant differences in
patients? Demographics were beyond the control of the authors. However,
such difference might have impacted the satisfaction scores, as it is
known that women have high rates of physical symptoms reporting [6].
Nonetheless, we do commend the authors? work on this important topic.
We agree with the authors that sub-Tenon's anaesthesia may be a better
choice in some patients undergoing cataract surgery. However, other forms
of topical anaesthesia may produce equally good, if not better, patient
satisfaction especially in selected patients.
References
1. Rüschen H, Celaschi D, Bunce C, Carr C. Randomised controlled
trial of sub-Tenon’s block versus topical anaesthesia for cataract
surgery: a comparison of patient satisfaction. Br J Ophthalmol. 2005; 89:
291-293.
2. Barequet IS, Soriano ES, Green WR, O'Brien TP. Provision of
anesthesia with single application of lidocaine 2% gel. J Cataract Refract
Surg. 1999 May;25(5):626-31.
3. Assia EI, Pras E, Yehezkel M, Rotenstreich Y, Jager-Roshu S.
Topical anesthesia using lidocaine gel for cataract surgery. J Cataract
Refract Surg. 1999 May;25(5):635-9.
4. Bardocci A, Lofoco G, Perdicaro S, Ciucci F, Manna L. Lidocaine
2% gel versus lidocaine 4% unpreserved drops for topical anesthesia in
cataract surgery: a randomized controlled trial. Ophthalmology. 2003
Jan;110(1):144-9.
5. Soliman MM, Macky TA, Samir MK. Comparative clinical trial of
topical anesthetic agents in cataract surgery: lidocaine 2% gel,
bupivacaine 0.5% drops, and benoxinate 0.4% drops. J Cataract Refract
Surg. 2004 Aug;30(8):1716-20.
6. van Wijk CM, Kolk AM. Sex differences in physical symptoms: the
contribution of symptom perception theory. Soc Sci Med. 1997 Jul;45(2):231
-46.
Dear Sir,
We read with interest the article by J A Montero and J M Ruiz-Moreno on ‘Optical coherence tomography (OCT) characterization of idiopathic central serous chorioretinopathy (ICSC)’.[1] We agree that OCT may offer a new approach to the staging and knowledge of ICSC, and may help the understanding of the mechanisms of the disease.
In our personal experience of OCT evaluation of 56 eyes we observ...
Dear Editor,
We read with keen interest the recently published article by Shields et al.[1] Cholesterol lowering agents may indeed evolve as a physiological and non-invasive therapeutic modality for this cosmetically disfiguring entity. We would like to raise a few pertinent issues related to this article.
We would like to draw your attention to the fact that there is a marked difference in the quali...
Dear Editor,
We read with great interest the article by McCarthy et al. ”Use of eye care services by people with diabetes: the Melbourne Visual Impairment Project”.[1]
We observed similar eyecare practices by rural and urban diabetics in a diabetic retinopathy-screening program. 4,517 rural and 3,199 urban diabetics above 30 years of age attended 51 diabetic retinopathy-screening camps conducted between Ju...
Dear Editor,
We are pleased at the interest shown by Dr. Stapleton and colleagues in our work [1] and we note their endorsement of our approach in adopting a clinical severity classification system for the assessment of contact lens associated keratitis.
Dr. Stapleton and colleagues have expressed concern at the high incidence of severe keratitis that we reported for hydrogel extended wear lenses. They sugg...
Dear Editor,
In “Endophthalmitis associated with the Ahmed glaucoma valve implant”[1], we can see the same predominant causative bacteria (Haemophilus and Streptococcus) that we have been seeing in other series of delayed onset endophthalmitis after glaucoma surgery since Mandelbaum et al. series.[2] This time [1], eight out of nine endophthalmitis had a delayed onset too, and two risk factors for endophthalmitis...
Dear Editor,
I would like to congratulate the author for this interesting manuscript.
Our ability to find the information we seek on the Internet is a function of how precise our queries are and how effectively we use search services. Poor queries return poor results; good queries return great results. Contrary to the hype surrounding "intelligent agents" and "artificial intelligence," the fact remains...
Dear Editor,
We read with interest Zia et al.’s article titled "Only rarely seen in dreams - visual experiences during cataract surgery" which highlights a professional artist’s and a poet’s respective renditions of their visual experiences during phacoemulsification and intraocular lens implantation under local anaesthesia.[1] While it is unclear from the report whether the artist’s elaborate drawing resembling...
Dear Editor,
I am pleased to have these very important questions on our study.
In our patients with normal tension glaucoma, some patients presented with decreased vision which was consistent with the typical glaucomatous optic nerve head changes and with the glaucomatous nerve fiber layer defects detected by visual field testing. In addition, none of them complained of decreased color vision. We did no...
Dear Editor,
With interest we read the recent retrospective case-control study on the causal interaction between endophthalmitis and intraocular lens (IOL) biomaterials by Wong and Chee [1]. They concluded that "…silicone (when compared with PMMA or acrylic IOL) … was independently associated with acute endophthalmitis". We believe that a few comments have to be addressed to clarify the findings for their read...
Dear Editor,
We read with great interest the article by Ruschen et al. comparing patient satisfaction during cataract surgery with sub-Tenon’s block (STB) versus topical anaesthesia (TOP) [1]. The authors concluded that in the setting of day case cataract surgery, patients reported significantly higher satisfaction scores with STB than TOP.
We would like to raise two issues for discussion. Firstly, th...
Pages