Dear Sir
Thanks for this notification
1. Preoperative and postoperative characteristics for the CF group are shown in Table 2 (line 13)
Answer: This was a typing error hoping if it will be corrected to: preoperative and postoperative characteristics for the AMG group are shown in Table 2
2. The study does not mention about the location postoperatively. How will the site of the ulcer change from central to paracentral and vice versa?
Answer: Eighteen from twenty patients in each group showed healing of the ulcer, and two cases in each group were sent for keratoplasty (from 4 to 8 days after intervention). So, there is no need to mention size of the ulcer. Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
So the description of the ulcer will be changed from peripheral to central.
There was no need to mention this as the ulcers healed.
3. There is no mention about the complications studied. Descemetocele and perforations occurred preoperatively.
Answer: Three cases with perforation and one case with descemetocele were referred to immediate keratoplasty, and other ulcers healed, so there were no complications to be mentioned. Regarding other complications in secondary outcome measures, there were no complications and this was mentio...
Dear Sir
Thanks for this notification
1. Preoperative and postoperative characteristics for the CF group are shown in Table 2 (line 13)
Answer: This was a typing error hoping if it will be corrected to: preoperative and postoperative characteristics for the AMG group are shown in Table 2
2. The study does not mention about the location postoperatively. How will the site of the ulcer change from central to paracentral and vice versa?
Answer: Eighteen from twenty patients in each group showed healing of the ulcer, and two cases in each group were sent for keratoplasty (from 4 to 8 days after intervention). So, there is no need to mention size of the ulcer. Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
So the description of the ulcer will be changed from peripheral to central.
There was no need to mention this as the ulcers healed.
3. There is no mention about the complications studied. Descemetocele and perforations occurred preoperatively.
Answer: Three cases with perforation and one case with descemetocele were referred to immediate keratoplasty, and other ulcers healed, so there were no complications to be mentioned. Regarding other complications in secondary outcome measures, there were no complications and this was mentioned in the discussion section in the second paragraph of the last page.
Dear Editor,
I read with interest the above randomised clinical study published by
Abdulhalim et al in BrJ Ophthal 2015;99:59-63.
The main outcome measures were location, size and depth of the lesion,
epithelialisation time and persistence of infection. Secondary outcome
measures include visual acuity and other complications.
Table 1 states Demographic data and preoperative characteristics for
conjunctival flap group.
Table 2 states Demographic data and preoperative characteristics for
amniotic transplant group.
However in the narration in Results-it states preoperative and
postoperative characteristics for the CF group are shown in Table 1 (line
5) preoperative and postoperative characteristics for the CF group are
shown in Table 1. preoperative and postoperative characteristics for the CF
group are shown in Table 2 (line 13). This is very confusing.
Table 3 shows a comparison of CF group and AMG. Here the preoperative and
postoperative characteristics are all in one table.
The main outcome measures were location. The study does not mention about
the location postoperatively. How will the site of the ulcer change from
central to paracentral and vice versa? There is no mention about the size
and depth of the ulcer- which is also a parameter that was studied.There is
no mention about the complications studied. Descematocoele and perforations...
Dear Editor,
I read with interest the above randomised clinical study published by
Abdulhalim et al in BrJ Ophthal 2015;99:59-63.
The main outcome measures were location, size and depth of the lesion,
epithelialisation time and persistence of infection. Secondary outcome
measures include visual acuity and other complications.
Table 1 states Demographic data and preoperative characteristics for
conjunctival flap group.
Table 2 states Demographic data and preoperative characteristics for
amniotic transplant group.
However in the narration in Results-it states preoperative and
postoperative characteristics for the CF group are shown in Table 1 (line
5) preoperative and postoperative characteristics for the CF group are
shown in Table 1. preoperative and postoperative characteristics for the CF
group are shown in Table 2 (line 13). This is very confusing.
Table 3 shows a comparison of CF group and AMG. Here the preoperative and
postoperative characteristics are all in one table.
The main outcome measures were location. The study does not mention about
the location postoperatively. How will the site of the ulcer change from
central to paracentral and vice versa? There is no mention about the size
and depth of the ulcer- which is also a parameter that was studied.There is
no mention about the complications studied. Descematocoele and perforations
occured pre-operatively.
Was the visual acuity best corrected or uncorrected visual acuity.
I whole heartedly appreciate the work conducted by Chan Yun Kim et al in studying the treatment patterns and medication adherence of patients with glaucoma in South Korea.This study concluded that medication non adherence was seen more commonly in males , increased daily number of administration and increase in the number of eyedrops. We have also conducted a similar study at our centre in North India and would like to share our results .Our results are in agreement to the work conducted by Chan Yun Kim stating that increased number of instillation and increased number of eyedrops contribute significantly to medication non adherence. However, in our study we also found that medication adherence varies in different severity grades of glaucoma with severe stages being significantly more adherent than mild to moderate stages of glaucoma.Additionally, there was no difference found in medication adherence among males or females.
We again express our gratitude to the researcher in enlightening our minds regarding medication adherence in South Korean population.
We thank Sarmad et al. for their interest in our publication. Our study is a retrospective review of several variables regarding non-traumatic corneal perforations (1). In handling clinical records for a retrospective analysis, missing variables represent a common problem. In relation to the location of corneal perforation, information was not available in 25 eyes thus the number does not match. Hence, in consideration of this inevitable flaw we decided not to include the anatomical location of perforation into the model presented in the manuscript, therefore all the variables included in this statistical model had no missing values.
Clinical treatment of corneal perforation is often complex and a single intervention may not address the patient full pathology, therefore more than one treatment is frequently used. (2) This explains the increased number of initial treatments in the first clinical intervention, one example of this scenario are the patients needing simultaneous tectonic penetrating keratoplasty to restore ocular integrity and concurrent amniotic membrane transplantation to aid in the control of ocular surface. (2)(3)
These two situations might not be precise in our manuscript, but we take the opportunity of this letter to clarify them. However, that is unquestionably far from compromising the validity of the conclusions. Definitely, as any retrospective study, and as we mention in the discussion of our article, there are li...
We thank Sarmad et al. for their interest in our publication. Our study is a retrospective review of several variables regarding non-traumatic corneal perforations (1). In handling clinical records for a retrospective analysis, missing variables represent a common problem. In relation to the location of corneal perforation, information was not available in 25 eyes thus the number does not match. Hence, in consideration of this inevitable flaw we decided not to include the anatomical location of perforation into the model presented in the manuscript, therefore all the variables included in this statistical model had no missing values.
Clinical treatment of corneal perforation is often complex and a single intervention may not address the patient full pathology, therefore more than one treatment is frequently used. (2) This explains the increased number of initial treatments in the first clinical intervention, one example of this scenario are the patients needing simultaneous tectonic penetrating keratoplasty to restore ocular integrity and concurrent amniotic membrane transplantation to aid in the control of ocular surface. (2)(3)
These two situations might not be precise in our manuscript, but we take the opportunity of this letter to clarify them. However, that is unquestionably far from compromising the validity of the conclusions. Definitely, as any retrospective study, and as we mention in the discussion of our article, there are limitations including the lack of a standard algorithm of treatment and the impossibility to include other variables that might alter the final outcomes of the patients. Therefore, and as we also discussed, this imply that the conclusions presented must be taken with caution. Thus, when interpreting the results of a retrospective study it is important to understand and be aware of the possible bias and limitations, allowing the reader to take advantage of the many strengths of this design into incorporation of knowledge into their daily clinical practice. (4)
References.
1) Loya-Garcia D, Serna-Ojeda JC, Pedro-Aguilar L, et al. Non-traumatic corneal perforations: aetiology, treatment and outcomes. Br J Ophthalmol. 2017;101(5):634-639.
2) Jhanji V, Young AL, Mehta JS, et al. Management of corneal perforation. Surv Ophthalmol. 2011;56(6):522-38.
3) Dua HS, Gomes JA, King AJ, et al. The Amniotic Membrane in Ophthalmology. Surv Opthalmol 2004; 49:51-77.
4) Euser AM, Zoccali C, Jager KJ, et al. Cohort studies: prospective versus retrospective. Nephron Clin Pract. 2009;113(3):c214-7.
Morphological and functional changes in recalcitrant diabetic
macular oedema after intravitreal dexamethasone implant.
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Morphological and functional changes in recalcitrant diabetic
macular oedema after intravitreal dexamethasone implant. Iacono et al. Br
J Ophthalmol 2016;http:/dx.doi.org/10.1136/bjophthalmol-201...
Morphological and functional changes in recalcitrant diabetic
macular oedema after intravitreal dexamethasone implant.
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Morphological and functional changes in recalcitrant diabetic
macular oedema after intravitreal dexamethasone implant. Iacono et al. Br
J Ophthalmol 2016;http:/dx.doi.org/10.1136/bjophthalmol-2016-308726.
Dear Editor
We would like to address several challenges that have arisen from the
study by Iacono et al (1), which can be specifically summarized below.
1. The study was uncontrolled and was carried out on a small study
population. There was a selection bias attributable to the heterogeneous
prior treatments administered to the patients, namely, panretinal
photocoagulation (PRP), grid photocoagulation, focal laser
photocoagulation, and anti-vascular endothelial growth factor (VEGF)
injections. Nothing was stated regarding the existence of a washout period
between previous PRP, focal/grid laser treatment and the first
dexamethasone implant.
2. Three outer retinal layers (eg, the external limiting membrane,
the ellipsoid zone, and retinal pigment epithelium [RPE]) were thoroughly
investigated as potential predictors of vision loss/improvement. There are
no data on the qualitative status of the fourth outer retinal layers, that
is, the interdigitation zone, which corresponds to the contact cylinder
represented by the apices of the RPE cells that encase part of the cone
outer segments.
3. Nothing was stated referring to the prevalence of the
vitreoretinal interface abnormalities (eg, vitreomacular adhesion/traction
and epiretinal membranes) and their changes during the study as potential
predictive factors on anatomical and visual outcomes after dexamethasone
implant in eyes affected by recalcitrant diabetic macular oedema (DME)
associated with proliferative diabetic retinopathy.
4. In the assessment of the final results of this study we have
considered the current assertion that evaluation of outcomes has to be
guided by anatomical measure data with visual changes as a secondary guide
(2). Accordingly, the outcomes of this series are unsatisfactory. Despite
a mean gain of approximately 10 Early Treatment Diabetic Retinopathy Study
letters in visual acuity correlated with a significant improvement in the
integrity of the outer retinal layers, the central macular thickness (CMT)
decreased significantly to 423 microns after treatment, a value that is
more than the cutoff for the upper level of normal CMT (3). Persistence of
this high value of the CMT highlights unresolved macular edema and
indicates that the disease process is still active and progressive,
requiring further treatment with antiangiogenic agents.
5. The patients in the present study suffered from persistent DME
with a 30.3 months'duration of the disease, who have been treated with an
average of 2.2 dexamethasone implants within the 12-month follow-up, a
number of injections which has proved to be insufficient to obtain dryness
of the macula. These facts favored the delayed occurrence of a chronic
retinal capillaropathy owing to permanent breakdown of the inner and outer
blood-retinal barriers (eg, pigmentary changes in the fovea, poorly
controlled severe recurrent macular edema, telangiectatic vessels with
leakage, and epiretinal membrane formation). This permanent retinal
capillaropathy was temporarily relieved by reduction of oedematous
component with treatment. However, this condition is incurable owing to
the irreversible ischemic lesions to the macular ganglion cell complex,
close to the foveola, with macular oedema being a minor factor.
Altogether, regardless of the therapeutic agents chosen (anti-VEGF
agents/corticosteroids), the efficacy of therapy depends primarily on the
promptness of the treatment after DME diagnosis. Any delay in treatment
will adversely influence the restoration of visual functions, which are
difficult to correct even with subsequent treatment (4,5).
References
1. Iacono P, Parodi MB, Scaramuzzi M, et al. Morphological and functional
changes in recalcitrant diabetic macular oedema after intravitral
dexamethasone implant. Br J Ophthalmol 2016;
http:/dx.doi.org/10.1136/bjophthalmol-2016-308726.
2. Freund KB, Korobelnik JF, Devenyl R, et al. Treat-and-extend regimens
with anti-VEGF agents in retinal diseases. Aliterature review and
consensus recommendations. Retina 2015;35(8):1489-1506.
3. Gover S, Murthy RK, Brar VS, et al. Normative data for macular
thickness by high-definition spectral-domain optical coherence tomography
(spectralis). Am J Ophthalmol 2009;148(2):266-271.
4. Calugaru D. Calugaru M. Real-world outcomes of ranibizumab treatment
for diabetic macular edema in a United Kingdom National Health Service
setting. Am J Ophthalmol 2017;174:175-176.
5. Calugaru D, Calugaru M. Comments to: Long-term efficacy and safety of
intrvitreal dexamethasone implant for the treatment of diabetic macular
edema. Eur J Ophthalmol 2016;26(6):e171-e172.
Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy. Jeong and Sagong. Br J Ophthalmol 2016; http: /dx.doi. org/ 10.1136/bjophthalmol-2016-309144.
Dear Editor
We would like to address several challenges that have arisen from the study by Jeong and Sagong (1), which can be specifically summarized below.
1. The study included a relatively small sample size of cases examined with a fairly short follow-up period.
2. Several relevant data are missing in the study. For example, the anatomic types of macular edema (diffuse/cystic changes within neurosensory retina/subretinal/sub retinal pigment epithelium (RPE) fluid/ mixed type) at baseline and at months 3 and 6; the qualitative status of the 4 outer retinal layers (eg, the external limiting membrane band, the ellipsoid zone, the interdigitation zone, and the retinal pigment epithelial band) at presentation as well as the magnitude of changes (disruption/absence) during the study as potential predictors of visual loss/improvement after aflibercept (Eylea; Regeneron Pharmaceuticals Inc., Tarrytown, New York, USA) treatment; the percentages of patients with complete polyp regression and...
Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy. Jeong and Sagong. Br J Ophthalmol 2016; http: /dx.doi. org/ 10.1136/bjophthalmol-2016-309144.
Dear Editor
We would like to address several challenges that have arisen from the study by Jeong and Sagong (1), which can be specifically summarized below.
1. The study included a relatively small sample size of cases examined with a fairly short follow-up period.
2. Several relevant data are missing in the study. For example, the anatomic types of macular edema (diffuse/cystic changes within neurosensory retina/subretinal/sub retinal pigment epithelium (RPE) fluid/ mixed type) at baseline and at months 3 and 6; the qualitative status of the 4 outer retinal layers (eg, the external limiting membrane band, the ellipsoid zone, the interdigitation zone, and the retinal pigment epithelial band) at presentation as well as the magnitude of changes (disruption/absence) during the study as potential predictors of visual loss/improvement after aflibercept (Eylea; Regeneron Pharmaceuticals Inc., Tarrytown, New York, USA) treatment; the percentages of patients with complete polyp regression and complete dry macula at month 6; the changes of central macular thickness (CMT) and subfoveal choroidal thickness (CT) at month 6; and the explanation of the mechanism by which the subfoveal CT was reduced after aflibercept therapy.
3. At baseline, the two groups of polypoidal choroidal vasculopathy (PCV) (2) were not comparable because there have been significant differences regarding the polyp number, branch vascular network (BVN) leakage, and subfoveal CT. The comparison should have been conducted only after using the multivariate regression analyses for adjustment of the baseline differences.
4. The comparative analysis of the 3-month outcomes highlighted a significant difference between the two groups relating to the reductions in the subfoveal CT, which was significantly higher in the type 2 PCV and no differences with respect to the percentages of the dry macula as well as the changes in the best corrected visual acuity (BCVA) score and CMT. The significantly higher proportion of the patients with complete polyp regression in the type 1 PCV should be interpreted considering the polyp number existing at baseline which was significantly higher in the type 1 than in the type 2 patients.
5. At 6 months, there was no significant difference in changes between the two groups regarding the percentages of the dry macula, BCVA score, and CMT. However, the evaluation of the treatment efficacy of aflibercept revealed a significant decrease of the subfoveal CT relative to the baseline values in the two types of PCV with a significantly greater reduction in the type 2 idiopathic PCV than the type 1 polypoidal choroidal neovascularisation. Conceivably, suppression of the choroidal vascular hyperpermeability and the vasoconstriction induced by aflibercept (3) may be more prominent in the type 2 PCV patients having a thicker choroid with abnormally enlarged and permeable choroidal vessels.
Altogether, in the short-term, the significant subfoveal CT thinning by aflibercept does not seem to result in visual deleterious changes. However, in the long-term, the prolonged inhibition of the vascular endothelial growth factor (VEGF) using aflibercept may affect the integrity of the choriocapillaris (CC) taking into account the key role played by the VEGF-A in the regulation of the survival and permeability of the CC. In addition, through the fragment cristalizable (Fc) domain, aflibercept can bind to the Fc receptor of both CC endothelial cells and red blood cells, leading to complement mediated cell death (4). Thus, the choroidal vascular impairment may affect the integrity of RPE and the outer retina with subsequent visual damaging effects because the choroid is involved in maintaining perfusion of the outer retinal layers and is the sole source of metabolic exchange for the fovea.
References
1. Jeong S, Sagong M. Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy. Br J Ophthalmol 2016; http:/ dx. doi. org/ 10.1136/bjophthalmol-2016-309144.
2. Calugaru D. Calugaru M. Comparison of time to retreatment and visual function between ranibizumab and aflibercept in age-related macular degeneration. Am J Ophthalmol 2017;174:181-182.
3. Hata M, Oishi A, Tsujikawa A, et al. Efficacy of intravitreal injection of aflibercept in neovascular age-related macular degeneration with or without vascular hyperpermeability. Invest Ophthalmol Vis Sci 2014;55:7874-7880.
4. Julien S, Biesemeier A, Taubitz T, Schraermeyer U. Different effects of intravitreally injected ranibizumab and aflibercept on retinal and choroidal tissues of monkey eyes. Br J Ophthalmol 2014;98:Z813-825.
Dear Editor,
We read your article titled- Non-traumatic corneal perforations: aetiology, treatment and outcomes: with great interest. Corneal perforation is an acute ophthalmic emergency. This review describes the aetiology, plausible location and the multiple ways to approach the management of this condition in a very a systematic manner.
We do appreciate the organised mode of stratification and care of non- traumatic corneal perforation presented in the article. However, although the results are interesting, we feel that caution should be exercised when drawing conclusions from this data.
Initially, in results there are 127 eyes of 116 patients under the review. However, while describing the anatomical location of the perforation, only 102 eyes have been accounted for, with no records for the remaining 25 eyes. This would change the calculated p value significantly.
Similarly, where the initial treatments for perforations were being reviewed 133 eyes were mentioned as treated, thus including six extra unaccounted for eyes to the total. This would seriously jeopardise the authenticity of the calculated results.
Hence, there appears to be serious doubts regarding the validity of the conclusions of this review. A clearer and more detailed explanation or a recalculation of the results is warranted in this regard.
I read with interest the article by Pawiroredjo et al1 which described an intervention programme to increase the cataract surgical rate in Suriname. I commend the team at the Suriname Eye Centre (SEC) for their efforts towards eliminating avoidable cataract blindness and visual impairment. The Suriname Rapid Assessment of Avoidable Blindness (2013-2014) survey showed that the proportion of eyes with a postoperative visual acuity <6/60 (poor outcome) was lowest in eyes operated at the SEC (8.5%), higher for the Cuban Mission Milagros (18.8%) and highest in surgeries performed by foreign humanitarian ophthalmic missions (33.3%).
In neighbouring Trinidad and Tobago, Persad and Bhola reported higher complication rates following cataract surgery performed by a foreign visiting team over a 2-week period compared to those done by local surgeons2. Despite a similar case mix, the visiting team had a sixfold higher vitreous loss rate and a fourfold higher overall surgical complication rate. The authors recommended careful screening of visiting surgical teams by relevant authorities. This supports Pawiroredjo’s suggestion of lowering complication rates and improving outcomes by regulating and limiting access of less experienced foreign ophthalmic teams to eye camps, where 50% of poor outcome was caused by intraoperative complications.
Suriname has achieved cataract surgical coverage (for all VA levels) of 90% in bilaterally blind or visually impaired individuals age...
I read with interest the article by Pawiroredjo et al1 which described an intervention programme to increase the cataract surgical rate in Suriname. I commend the team at the Suriname Eye Centre (SEC) for their efforts towards eliminating avoidable cataract blindness and visual impairment. The Suriname Rapid Assessment of Avoidable Blindness (2013-2014) survey showed that the proportion of eyes with a postoperative visual acuity <6/60 (poor outcome) was lowest in eyes operated at the SEC (8.5%), higher for the Cuban Mission Milagros (18.8%) and highest in surgeries performed by foreign humanitarian ophthalmic missions (33.3%).
In neighbouring Trinidad and Tobago, Persad and Bhola reported higher complication rates following cataract surgery performed by a foreign visiting team over a 2-week period compared to those done by local surgeons2. Despite a similar case mix, the visiting team had a sixfold higher vitreous loss rate and a fourfold higher overall surgical complication rate. The authors recommended careful screening of visiting surgical teams by relevant authorities. This supports Pawiroredjo’s suggestion of lowering complication rates and improving outcomes by regulating and limiting access of less experienced foreign ophthalmic teams to eye camps, where 50% of poor outcome was caused by intraoperative complications.
Suriname has achieved cataract surgical coverage (for all VA levels) of 90% in bilaterally blind or visually impaired individuals aged ≥50 years.3 This has been accomplished by training its local surgeons in phacoemulsification and strengthening ophthalmic services at the SEC, resulting in a self-sufficient and sustainable system. This is in line with WHO’s framework for strengthening health systems and use of cataract surgery as a proxy indicator for the provision of eye care services4. It could also explain the difference in surgical outcomes between visiting and local teams. Other Caribbean territories should follow the Suriname initiative to improve eye care services in the region.
References:
1. Pawiroredjo JC, Minderhoud J, Mans DRA, et al. Br J Ophthalmol 2017;101:89–93.
2. Persad S, Bhola R West Indian Med J 2010;Vol 59 (suppl. 3)
3. Minderhoud J, Pawiroredjo JC, Themen HCI, et al. Blindness and visual impairment in the Republic of Suriname. Ophthalmology 2015;122:2147–9.
4. World Health Organization Universal eye health: a global action plan 2014-2019 available at http://www.who.int/blindness/actionplan/en/
We thank the authors[1] but wish to clarify several points. Stating that ‘glaucoma diagnosis is more common in OSA populations’ is controversial. Glaucoma diagnosis was not more common in our study (RR 1.01, CI 0.85-1.19), which censored prospectively from time of OSA coding throughout England from 1999-2011[2]. This is the largest and longest individual study conducted in this area. Several previous studies also observed no association.
The authors recommend accounting for ‘risk-associated conditions’. Accounting for potential confounders is important in evaluation of positive associations but less relevant in their absence. We agree that studies in different populations would be useful, particularly in Asia where OAG may differ.
In recommending a prospective RCT assessing ‘IOP/visual field progression before and after CPAP’, the authors are asking a different question. We have previously advocated this: ‘even in the absence of a positive association, it might still be relevant to identify those patients with genuine co-existence of OSA and POAG, particularly if evidence were to emerge … that OSA treatment could reduce glaucomatous progression’[2].
Our study never aimed to measure OSA point prevalence, so it is inappropriate to compare a speculative ‘base rate of 2.5%’ with prevalence estimates from a different continent/age-group. Moreover, our OSA cohort represented more severe disease; this should have exaggerated rather than ‘blurred’ any potentia...
We thank the authors[1] but wish to clarify several points. Stating that ‘glaucoma diagnosis is more common in OSA populations’ is controversial. Glaucoma diagnosis was not more common in our study (RR 1.01, CI 0.85-1.19), which censored prospectively from time of OSA coding throughout England from 1999-2011[2]. This is the largest and longest individual study conducted in this area. Several previous studies also observed no association.
The authors recommend accounting for ‘risk-associated conditions’. Accounting for potential confounders is important in evaluation of positive associations but less relevant in their absence. We agree that studies in different populations would be useful, particularly in Asia where OAG may differ.
In recommending a prospective RCT assessing ‘IOP/visual field progression before and after CPAP’, the authors are asking a different question. We have previously advocated this: ‘even in the absence of a positive association, it might still be relevant to identify those patients with genuine co-existence of OSA and POAG, particularly if evidence were to emerge … that OSA treatment could reduce glaucomatous progression’[2].
Our study never aimed to measure OSA point prevalence, so it is inappropriate to compare a speculative ‘base rate of 2.5%’ with prevalence estimates from a different continent/age-group. Moreover, our OSA cohort represented more severe disease; this should have exaggerated rather than ‘blurred’ any potential association.
The finding of a temporary elevation in OSA rate ratios soon after POAG diagnosis (offset later) is likely explained by increased effort screening for OSA through publicity around this potential association. These findings do not necessarily demonstrate a ‘lack of OSA screening’. Our findings do suggest that OSA screening might be directed towards AMD patients[3,4].
The recommendation of a ‘national OSA screening programme for all’ is a separate matter that should be judged on its own merits in an evidence-based manner.
References
1. Weir RE and Hozer KW. Ophthalmologists wake obstructive sleeping dogma. BJO 2017 eLetter
2. Keenan TD, Goldacre R, Goldacre MJ. Associations between obstructive sleep apnoea, primary open angle glaucoma and age-related macular degeneration: record linkage study. BJO 2017;101(2):155-159.
3. Keenan TD. Correspondence. Retina 2016;36(7):e70-1
4. Schaal S, Sherman MP, Nesmith B, Barak Y. Untreated obstructive sleep apnea hinders response to bevacizumab in age-related macular degeneration. Retina 2016;36(4):791-7
Dear Sirs,
We are grateful to Sabour and Ghassemi for their interest in our recent
article[1]. In our understanding, they query why we did not use intra class
correlation (ICC) as a measure for precision.
Our test-retest reliability (absolute agreement ICC) is derived from the
maximum likelihood (LM) estimates of the one-way random effects model of
the form: yij...
Dear Sirs,
We are grateful to Sabour and Ghassemi for their interest in our recent
article[1]. In our understanding, they query why we did not use intra class
correlation (ICC) as a measure for precision.
Our test-retest reliability (absolute agreement ICC) is derived from the
maximum likelihood (LM) estimates of the one-way random effects model of
the form: yij=Mu+ri+Epsilonij, where yij is the measurement of the ith eye by the jth measurement (say spherical equivalent measured on the first (second or third) occasion), Mu is the mean rating (say mean spherical equivalent), ri is the eye random effect and Epsilonij is a random error. As described in Rabe-Hesketh and Skrondal[2], the reliability is calculated as
p ?=? ?/(? ?+? ?),
where Psi is a between-subject variance and Theta is a within-subject variance.
Here we assume that n eyes are randomly selected from the population of
potential eyes. Each one is measured by a different set of k measurements,
randomly drawn from the population of potential measurements. The
consistency of agreement is not defined in this case, as each eye is
evaluated by a different set of measurements. Thus, there is no between-
measurements variability in this model.
We agree that clinical judgement is paramount, which is why, indeed, we
state in our paper (p 5) that "the clinical interpretation of the
agreement range (...) is vital (underlining added)". It is before the
background of such clinical interpretations in the paper and of the above
explanations that we derived our conclusions in, as we trust, an
appropriate way.
Yours respectfully,
References
1. Huelle JO, Katz T, Druchkiv V, et al. First clinicial results on
the feasibility, quality and reproducibility of aberrometry-based
intraoperative refraction during cataract surgery. Br J Ophthalmol 2014.
2. Rabe-Hesketh S, Skrondal A. Multilevel and Longitudinal Modeling Using
Stata, Second Edition: Stata Press, 2008.
3. McAlinden C, Khadka J, Pesudovs K. Statistical methods for conducting
agreement (comparison of clinical tests) and precision (repeatability or
reproducibility) studies in optometry and ophthalmology. Ophthalmic
Physiol Opt 2011;31(4):330-8.
Dear Sir
Show MoreThanks for this notification
1. Preoperative and postoperative characteristics for the CF group are shown in Table 2 (line 13)
Answer: This was a typing error hoping if it will be corrected to: preoperative and postoperative characteristics for the AMG group are shown in Table 2
2. The study does not mention about the location postoperatively. How will the site of the ulcer change from central to paracentral and vice versa?
Answer: Eighteen from twenty patients in each group showed healing of the ulcer, and two cases in each group were sent for keratoplasty (from 4 to 8 days after intervention). So, there is no need to mention size of the ulcer. Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
Regarding site of the ulcer; some paracentral ulcer are creeping and/or enlarging in size to involve the central part.
So the description of the ulcer will be changed from peripheral to central.
There was no need to mention this as the ulcers healed.
3. There is no mention about the complications studied. Descemetocele and perforations occurred preoperatively.
Answer: Three cases with perforation and one case with descemetocele were referred to immediate keratoplasty, and other ulcers healed, so there were no complications to be mentioned. Regarding other complications in secondary outcome measures, there were no complications and this was mentio...
Dear Editor,
I read with interest the above randomised clinical study published by
Abdulhalim et al in BrJ Ophthal 2015;99:59-63.
The main outcome measures were location, size and depth of the lesion,
epithelialisation time and persistence of infection. Secondary outcome
measures include visual acuity and other complications.
Table 1 states Demographic data and preoperative characteristics for
conjunctival flap group.
Table 2 states Demographic data and preoperative characteristics for
amniotic transplant group.
However in the narration in Results-it states preoperative and
postoperative characteristics for the CF group are shown in Table 1 (line
5) preoperative and postoperative characteristics for the CF group are
shown in Table 1. preoperative and postoperative characteristics for the CF
group are shown in Table 2 (line 13). This is very confusing.
Table 3 shows a comparison of CF group and AMG. Here the preoperative and
postoperative characteristics are all in one table.
The main outcome measures were location. The study does not mention about
Show Morethe location postoperatively. How will the site of the ulcer change from
central to paracentral and vice versa? There is no mention about the size
and depth of the ulcer- which is also a parameter that was studied.There is
no mention about the complications studied. Descematocoele and perforations...
Dear sir/maam
I whole heartedly appreciate the work conducted by Chan Yun Kim et al in studying the treatment patterns and medication adherence of patients with glaucoma in South Korea.This study concluded that medication non adherence was seen more commonly in males , increased daily number of administration and increase in the number of eyedrops. We have also conducted a similar study at our centre in North India and would like to share our results .Our results are in agreement to the work conducted by Chan Yun Kim stating that increased number of instillation and increased number of eyedrops contribute significantly to medication non adherence. However, in our study we also found that medication adherence varies in different severity grades of glaucoma with severe stages being significantly more adherent than mild to moderate stages of glaucoma.Additionally, there was no difference found in medication adherence among males or females.
We again express our gratitude to the researcher in enlightening our minds regarding medication adherence in South Korean population.
Dear editor.
We thank Sarmad et al. for their interest in our publication. Our study is a retrospective review of several variables regarding non-traumatic corneal perforations (1). In handling clinical records for a retrospective analysis, missing variables represent a common problem. In relation to the location of corneal perforation, information was not available in 25 eyes thus the number does not match. Hence, in consideration of this inevitable flaw we decided not to include the anatomical location of perforation into the model presented in the manuscript, therefore all the variables included in this statistical model had no missing values.
Clinical treatment of corneal perforation is often complex and a single intervention may not address the patient full pathology, therefore more than one treatment is frequently used. (2) This explains the increased number of initial treatments in the first clinical intervention, one example of this scenario are the patients needing simultaneous tectonic penetrating keratoplasty to restore ocular integrity and concurrent amniotic membrane transplantation to aid in the control of ocular surface. (2)(3)
These two situations might not be precise in our manuscript, but we take the opportunity of this letter to clarify them. However, that is unquestionably far from compromising the validity of the conclusions. Definitely, as any retrospective study, and as we mention in the discussion of our article, there are li...
Show MoreMorphological and functional changes in recalcitrant diabetic macular oedema after intravitreal dexamethasone implant. Dan Calugaru, Mihai Calugaru Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Morphological and functional changes in recalcitrant diabetic macular oedema after intravitreal dexamethasone implant. Iacono et al. Br J Ophthalmol 2016;http:/dx.doi.org/10.1136/bjophthalmol-201...
Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Short-term efficacy of intravitreal aflibercept depending on angiographic classification of polypoidal choroidal vasculopathy. Jeong and Sagong. Br J Ophthalmol 2016; http: /dx.doi. org/ 10.1136/bjophthalmol-2016-309144.
Dear Editor
Show MoreWe would like to address several challenges that have arisen from the study by Jeong and Sagong (1), which can be specifically summarized below.
1. The study included a relatively small sample size of cases examined with a fairly short follow-up period.
2. Several relevant data are missing in the study. For example, the anatomic types of macular edema (diffuse/cystic changes within neurosensory retina/subretinal/sub retinal pigment epithelium (RPE) fluid/ mixed type) at baseline and at months 3 and 6; the qualitative status of the 4 outer retinal layers (eg, the external limiting membrane band, the ellipsoid zone, the interdigitation zone, and the retinal pigment epithelial band) at presentation as well as the magnitude of changes (disruption/absence) during the study as potential predictors of visual loss/improvement after aflibercept (Eylea; Regeneron Pharmaceuticals Inc., Tarrytown, New York, USA) treatment; the percentages of patients with complete polyp regression and...
Dear Editor,
We read your article titled- Non-traumatic corneal perforations: aetiology, treatment and outcomes: with great interest. Corneal perforation is an acute ophthalmic emergency. This review describes the aetiology, plausible location and the multiple ways to approach the management of this condition in a very a systematic manner.
We do appreciate the organised mode of stratification and care of non- traumatic corneal perforation presented in the article. However, although the results are interesting, we feel that caution should be exercised when drawing conclusions from this data.
Initially, in results there are 127 eyes of 116 patients under the review. However, while describing the anatomical location of the perforation, only 102 eyes have been accounted for, with no records for the remaining 25 eyes. This would change the calculated p value significantly.
Similarly, where the initial treatments for perforations were being reviewed 133 eyes were mentioned as treated, thus including six extra unaccounted for eyes to the total. This would seriously jeopardise the authenticity of the calculated results.
Hence, there appears to be serious doubts regarding the validity of the conclusions of this review. A clearer and more detailed explanation or a recalculation of the results is warranted in this regard.
I read with interest the article by Pawiroredjo et al1 which described an intervention programme to increase the cataract surgical rate in Suriname. I commend the team at the Suriname Eye Centre (SEC) for their efforts towards eliminating avoidable cataract blindness and visual impairment. The Suriname Rapid Assessment of Avoidable Blindness (2013-2014) survey showed that the proportion of eyes with a postoperative visual acuity <6/60 (poor outcome) was lowest in eyes operated at the SEC (8.5%), higher for the Cuban Mission Milagros (18.8%) and highest in surgeries performed by foreign humanitarian ophthalmic missions (33.3%).
In neighbouring Trinidad and Tobago, Persad and Bhola reported higher complication rates following cataract surgery performed by a foreign visiting team over a 2-week period compared to those done by local surgeons2. Despite a similar case mix, the visiting team had a sixfold higher vitreous loss rate and a fourfold higher overall surgical complication rate. The authors recommended careful screening of visiting surgical teams by relevant authorities. This supports Pawiroredjo’s suggestion of lowering complication rates and improving outcomes by regulating and limiting access of less experienced foreign ophthalmic teams to eye camps, where 50% of poor outcome was caused by intraoperative complications.
Suriname has achieved cataract surgical coverage (for all VA levels) of 90% in bilaterally blind or visually impaired individuals age...
Show MoreWe thank the authors[1] but wish to clarify several points. Stating that ‘glaucoma diagnosis is more common in OSA populations’ is controversial. Glaucoma diagnosis was not more common in our study (RR 1.01, CI 0.85-1.19), which censored prospectively from time of OSA coding throughout England from 1999-2011[2]. This is the largest and longest individual study conducted in this area. Several previous studies also observed no association.
The authors recommend accounting for ‘risk-associated conditions’. Accounting for potential confounders is important in evaluation of positive associations but less relevant in their absence. We agree that studies in different populations would be useful, particularly in Asia where OAG may differ.
In recommending a prospective RCT assessing ‘IOP/visual field progression before and after CPAP’, the authors are asking a different question. We have previously advocated this: ‘even in the absence of a positive association, it might still be relevant to identify those patients with genuine co-existence of OSA and POAG, particularly if evidence were to emerge … that OSA treatment could reduce glaucomatous progression’[2].
Our study never aimed to measure OSA point prevalence, so it is inappropriate to compare a speculative ‘base rate of 2.5%’ with prevalence estimates from a different continent/age-group. Moreover, our OSA cohort represented more severe disease; this should have exaggerated rather than ‘blurred’ any potentia...
Show MoreDear Sirs, We are grateful to Sabour and Ghassemi for their interest in our recent article[1]. In our understanding, they query why we did not use intra class correlation (ICC) as a measure for precision. Our test-retest reliability (absolute agreement ICC) is derived from the maximum likelihood (LM) estimates of the one-way random effects model of the form: yij...
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