To,
The editor
We would like to congratulate Huang et al. for their study ‘Combined subconjunctival injection of dexamethasone for the management of acute primary angle closure: a randomised controlled trial’.1 However, we have few queries and seek your kind attention.
First, as mentioned in this article, a previous study in dogs showed combination of topical anti-inflammatory eye drops was beneficial during treatment.2They had conducted this present study as there was no data on humans regarding a randomised controlled trial that demonstrates the effectiveness of anti-inflammatory drugs for the treatment of human eyes suffering from acute primary angle closure (APAC). However, as the title suggested combination of subconjunctival dexamethasone injection, it implied combination of it with other anti-inflammatory drugs. However, the injection group was not subjected to any other anti-inflammatory drugs.
Second, the authors’ previous study showed that the inflammatory response in the aqueous humor from APAC patient was evident and that multiple inflammatory factors were elevated significantly.3 Topical steroids help to reduce intraocular inflammation make the patient more comfortable.4 However; the control group was not subjected to any topical anti-inflammatory drug.
Third, we are interested to know about the range of intraocular pressure (IOP) in those 42 eyes; the highest and lowest IOP recorded.
Fourth, we are also interested to know r...
To,
The editor
We would like to congratulate Huang et al. for their study ‘Combined subconjunctival injection of dexamethasone for the management of acute primary angle closure: a randomised controlled trial’.1 However, we have few queries and seek your kind attention.
First, as mentioned in this article, a previous study in dogs showed combination of topical anti-inflammatory eye drops was beneficial during treatment.2They had conducted this present study as there was no data on humans regarding a randomised controlled trial that demonstrates the effectiveness of anti-inflammatory drugs for the treatment of human eyes suffering from acute primary angle closure (APAC). However, as the title suggested combination of subconjunctival dexamethasone injection, it implied combination of it with other anti-inflammatory drugs. However, the injection group was not subjected to any other anti-inflammatory drugs.
Second, the authors’ previous study showed that the inflammatory response in the aqueous humor from APAC patient was evident and that multiple inflammatory factors were elevated significantly.3 Topical steroids help to reduce intraocular inflammation make the patient more comfortable.4 However; the control group was not subjected to any topical anti-inflammatory drug.
Third, we are interested to know about the range of intraocular pressure (IOP) in those 42 eyes; the highest and lowest IOP recorded.
Fourth, we are also interested to know regarding any window period from onset of acute attack for maximum efficacy of subconjunctival dexamethasone injection?
References
1. Huang W, Li X, Gao K, et al. Combined subconjunctival injection of dexamethasone for the management of acute primary angle closure: a randomised controlled trial. Br J Ophthalmol 2019;0:1–5. doi:10.1136/bjophthalmol-2018-313473
2. Miller PE, Schmidt GM, Vainisi SJ, et al. The efficacy of topical prophylactic antiglaucoma therapy in primary closed angle glaucoma in dogs: a multicenter clinical trial. J Am Anim Hosp Assoc 2000;36:431–8.
3. Huang W, Gao X, Chen S, et al. Vascular endothelial growth factor is increased in aqueous humor of acute primary angle-closure eyes. J Glaucoma 2016;25:e647–51.
4. See JL, Aquino MD, Aduan J, Chew PT. Management of angle closure glaucoma. Indian J Ophthalmol 2011;59, Suppl S1:82-7.
Dear Editor,
With great interest, we have read the article by Feihui et al.[1]
This study has investigated the sensitivities and specificities of different diagnostic criteria based on the OCT for glaucoma detection. According to the article abnormal superotemporal and inferotemporal RNFLT attained a higher sensitivity than abnormal superotemporal and inferotemporal BMO-MRW to detect mild glaucoma. However, our query arises when “Integration of RNFLT / BMO-MRW assessment was done”. The author stated, integrating RNFLT and BMO-MRW assessment did not change the sensitivity and specificity of RNFLT but increased the sensitivity of BMO-MRW for detection of glaucoma. To quote the author, the author paradoxically stated “ Our finding underscores the importance of RNFL imaging and measurement in the diagnostic evaluation of glaucoma”. We are interested to know if sensitivity and specificity on combination is increased, why would the diagonostic performance not increased? Reis et al stated, Bruch's membrane opening minimum rim width (BMO‐MRW) reproducibility were comparable and excellent in both healthy subjects and patients with glaucoma to that of RNFLT measurements.[2]
The article also did not include head tilt in the confounding covariates, as it was previously stated, head tilt significantly affects OCT image orientation as measured by the FoBMO angle.[3]
The article has also not mentioned dimensions of the optic nerve head (ONH) as stated previo...
Dear Editor,
With great interest, we have read the article by Feihui et al.[1]
This study has investigated the sensitivities and specificities of different diagnostic criteria based on the OCT for glaucoma detection. According to the article abnormal superotemporal and inferotemporal RNFLT attained a higher sensitivity than abnormal superotemporal and inferotemporal BMO-MRW to detect mild glaucoma. However, our query arises when “Integration of RNFLT / BMO-MRW assessment was done”. The author stated, integrating RNFLT and BMO-MRW assessment did not change the sensitivity and specificity of RNFLT but increased the sensitivity of BMO-MRW for detection of glaucoma. To quote the author, the author paradoxically stated “ Our finding underscores the importance of RNFL imaging and measurement in the diagnostic evaluation of glaucoma”. We are interested to know if sensitivity and specificity on combination is increased, why would the diagonostic performance not increased? Reis et al stated, Bruch's membrane opening minimum rim width (BMO‐MRW) reproducibility were comparable and excellent in both healthy subjects and patients with glaucoma to that of RNFLT measurements.[2]
The article also did not include head tilt in the confounding covariates, as it was previously stated, head tilt significantly affects OCT image orientation as measured by the FoBMO angle.[3]
The article has also not mentioned dimensions of the optic nerve head (ONH) as stated previously, in small optic discs, BMO-MRW and peripapillary RNFLT (OCT) have similar sensitivity to discriminate glaucoma patients. In glaucomatous patients, BMO-MRW correlates strongest with visual field function, but the diameter of the disc has to be considered.[4]
The article has no mention regarding type of glaucoma, as the OCT scanning parameters BMO-MRW and RNFLT were significantly influenced by papillary leakage in uveitic eyes with and without glaucoma. RNFLT values were also significantly increased while active inflammation was present.[5]
References:
1. Zheng F, Yu M, Leung CK . Diagnostic criteria for detection of retinal nerve fibre layer thickness and neuroretinal rim width abnormalities in glaucoma. British Journal of Ophthalmology Published Online First: 30 May 2019. doi: 10.1136/bjophthalmol-2018-313581
2. Reis, A. S., Zangalli, C. e., et al. Intra‐ and interobserver reproducibility of Bruch's membrane opening minimum rim width measurements with spectral domain optical coherence tomography. Acta Ophthalmol, 95: e548-e555. doi:10.1111/aos.13464
3. Mohammad S , Jarrar FS , Torres LA, et al. Impact of Head Tilt on Optical Coherence Tomography Image Orientation. J Glaucoma. 2018 Dec; 27(12):1042-1045.
4. Enders P, Schaub F, Adler W, et al. The use of Bruch's membrane opening-based optical coherence tomography of the optic nerve head for glaucoma detection in microdiscs British Journal of Ophthalmology 2017; 101:530-535.
5. Kriegel MF, Heiligenhaus A, Heinz C et al. Influence of uveitis on Bruch’s membrane opening minimum rim width and retinal nerve fibre layer thickness measurements. British Journal of Ophthalmology.18 December 2018. doi: 10.1136/bjophthalmol-2018-313016
To the Editor:
We herein respond to the letter written by Camus et al raising the issue of “ultra-low” dose radiation therapy (4 Gy) vs. the “standard low-dose” radiation therapy (24-30 Gy) for lymphomas of the orbit, eyelid, and conjunctiva, also referred to as “ocular adnexal lymphoma” (OAL). First off, it is important to point out that the goals of the retrospective multicenter general review of marginal zone lymphoma coordinated by Professor Steffen Heegaard in Denmark which also included some of our patients from M. D. Anderson was not to compare the efficacy of various treatment strategies.(1) Indeed it is challenging to draw practice altering conclusions from a retrospective multi-center study given the usual limitations, most notably the variation in staging and treatment approaches across various continents as noted by Camus et al.
However, we agree with Camus et al that our encouraging preliminary observations in 22 patients with OAL treated with ultra-low dose radiation therapy (4Gy) suggested a very good response rate (100% ORR:86% CR, 14%% PR) for B-cell orbital and ocular adnexal lymphomas;(2) as such we started a prospective trial of ultra-low dose radiation for ocular adnexal lymphoma patients at MD Anderson Cancer Center soon thereafter (Clinicaltrials.gov identifier NCT02494700)The study aims to evaluate the efficacy of response adapted radiation therapy for this patient population, whereby all patients are treated to an initial 4 Gy in...
To the Editor:
We herein respond to the letter written by Camus et al raising the issue of “ultra-low” dose radiation therapy (4 Gy) vs. the “standard low-dose” radiation therapy (24-30 Gy) for lymphomas of the orbit, eyelid, and conjunctiva, also referred to as “ocular adnexal lymphoma” (OAL). First off, it is important to point out that the goals of the retrospective multicenter general review of marginal zone lymphoma coordinated by Professor Steffen Heegaard in Denmark which also included some of our patients from M. D. Anderson was not to compare the efficacy of various treatment strategies.(1) Indeed it is challenging to draw practice altering conclusions from a retrospective multi-center study given the usual limitations, most notably the variation in staging and treatment approaches across various continents as noted by Camus et al.
However, we agree with Camus et al that our encouraging preliminary observations in 22 patients with OAL treated with ultra-low dose radiation therapy (4Gy) suggested a very good response rate (100% ORR:86% CR, 14%% PR) for B-cell orbital and ocular adnexal lymphomas;(2) as such we started a prospective trial of ultra-low dose radiation for ocular adnexal lymphoma patients at MD Anderson Cancer Center soon thereafter (Clinicaltrials.gov identifier NCT02494700)The study aims to evaluate the efficacy of response adapted radiation therapy for this patient population, whereby all patients are treated to an initial 4 Gy in 2 fractions and the additional 20 Gy (to complete the current standard of care radiation therapy dose of 24 Gy, is reserved for non-responders). The total accrual goal for this prospective trial is 50 patients; to date we have enrolled 41 patients in this prospective trial and have also treated at least 30 additional patients off protocol with the ultra-low dose regimen (inclusive of the patients reported in our initial retrospective analysis). We fully expect to publish the results of this prospective trial in a major oncology journal once the total accrual goal is reached. Based on our interim analysis and our collective observations in over 70 orbits treated with ultra-low dose radiation therapy (4Gy) at MD Anderson to date, we are optimistic that this significant lowering of dose of radiation therapy will be a major paradigm shift for management of low grade ocular adnexal lymphomas in routine practice in the future.
As Camus et al pointed out this much lower dose of radiation therapy is associated with significantly less ocular toxicity, it is less expensive, more convenient for patients (only two sessions of radiation), and importantly can also be repeated in cases of relapse or progression over time in the orbit. With regards to the issue of follow up time, we have been carefully following our original 22 patients treated with ultra-low dose radiation (4 Gy) and published in 2016.(2) We plan to publish a follow-up study on those original 22 patients once the median follow up time gets closer to 5 years. This may coincide with the publication of our prospective trial data and hopefully the two follow up publications will decrease the understandable sense of “dilemma” expressed by Camus et al regarding the ideal radiation dose for low grade , stage IE, ocular adnexal lymphomas.
Corresponding Author:
Bita Esmaeli, MD, FACS
Orbital Oncology & Ophthalmic Plastic Surgery
Department of Plastic Surgery
The University of Texas MD Anderson Cancer Center
1515 Holcombe Blvd, Unit 1488, Houston, Texas 77030
Tel: 713-792-4457. Fax: 713-794-4662
1. Hindsø TG, Esmaeli B, Holm F, et al. International multicentre retrospective cohort study of ocular
adnexal marginal zone B-cell lymphoma. Br. J. Ophthalmol. 2019;bjophthalmol-2019-314008.
2. Pinnix CC, Dabaja BS, Milgrom SA, et al. Ultra-low-dose radiotherapy for definitive management of
ocular adnexal B-cell lymphoma. Head Neck. 2017;39(6):1095–1100.
Dear editor, we have read with great interest the article presented by Melo et al.1 The authors provide good evidence of silicone oil release in injections from lubricated syringes. However, the likelihood of false-negative data may have been high because of lack of a staining method (Sudan III, for example) to differentiate and highlight small droplets, as previously described.2
Although injectable fluid contamination with syringe silicone oil has been known for decades,3,4 the lack of awareness of all medical specialties about this problem is impressive. The most concerning, still controversial long-term effect of silicone oil exposure is the development of an autoimmune/inflammatory syndrome induced by adjuvants, also known as ASIA syndrome.5
Given the massive amount of injections given worldwide, silicone oil injected seems safer than one would imagine, however, it is worth remembering that if the physician is unaware of the fact of the silicone oil injection, the diagnosis is omitted as a possible hypothesis. Enlarged lymph nodes or skin nodules with evidence of granulomas are assumed as sarcoidosis, and lumps in the abdomen of diabetic patients are all diagnosed as insulin fat hypertrophy, and if a biopsy is performed, the likely cause of the granuloma would be the injected therapeutic protein or an autoimmune phenomenon. If the physicians are informed that a patient received silicone oil injections the diagnoses change to silicone oil induced granuloma...
Dear editor, we have read with great interest the article presented by Melo et al.1 The authors provide good evidence of silicone oil release in injections from lubricated syringes. However, the likelihood of false-negative data may have been high because of lack of a staining method (Sudan III, for example) to differentiate and highlight small droplets, as previously described.2
Although injectable fluid contamination with syringe silicone oil has been known for decades,3,4 the lack of awareness of all medical specialties about this problem is impressive. The most concerning, still controversial long-term effect of silicone oil exposure is the development of an autoimmune/inflammatory syndrome induced by adjuvants, also known as ASIA syndrome.5
Given the massive amount of injections given worldwide, silicone oil injected seems safer than one would imagine, however, it is worth remembering that if the physician is unaware of the fact of the silicone oil injection, the diagnosis is omitted as a possible hypothesis. Enlarged lymph nodes or skin nodules with evidence of granulomas are assumed as sarcoidosis, and lumps in the abdomen of diabetic patients are all diagnosed as insulin fat hypertrophy, and if a biopsy is performed, the likely cause of the granuloma would be the injected therapeutic protein or an autoimmune phenomenon. If the physicians are informed that a patient received silicone oil injections the diagnoses change to silicone oil induced granulomas and lymphatic migration of silicone oil.
If patients had the option to choose between receiving injections with or without silicone oil, which would they choose? Would the regulatory agencies and manufacturers listen to their option?
The generalized adoption of silicone oil free syringes is likely the future. Meanwhile, the flush technique can be adopted to minimize the possibility of adverse reactions,2 which can occur decades after an injection.
References:
1. Melo GB, Emerson GG, Dias Jr CS, Morais FB, Lima Filho A de S, Ota S, et al. Release of silicone oil and the off-label use of syringes in ophthalmology. Br J Ophthalmol 2019. doi:10.1136/bjophthalmol-2019-313823.
2. Wambier CG, Assis de Andrade E, Cruz LS, et al. Flush technique to minimize adverse reactions from syringe lubricant (silicone oil). J Am Acad Dermatol. December 2018. doi:10.1016/j.jaad.2018.12.014
3. Chantelau EA, Berger M. Pollution of Insulin With Silicone Oil, a Hazard of Disposable Plastic Syringes. Lancet. 1985;325(8443):1459. doi:10.1016/S0140-6736(85)91892-6
4. Baldwin RN. Contamination of insulin by silicone oil: a potential hazard of plastic insulin syringes. Diabet Med. 1988;5(8):789-790.
5. Perricone C, Colafrancesco S, Mazor RD, Soriano A, Agmon-Levin N, Shoenfeld Y. Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) 2013: Unveiling the pathogenic, clinical and diagnostic aspects. J Autoimmun. 2013;47:1-16. doi:10.1016/j.jaut.2013.10.004
Dear editor, we received with interest the comments by Wambier et al.1 They provided interestingly new insights in possible adverse effects of silicone oil on the human body. If enlarged lymph nodes and skin nodules assumed as sarcoidosis, and lumps in the abdomen of diabetic patients diagnosed as insulin fat hypertrophy are proved to be secondary to the silicone oil released by the syringes, a remarkable paradigm shift will be achieved. Incidentally, the idea of an inflammatory/immunological association to the presence of silicone oil droplets is in agreement with our yet unproven hypothesis that agitation of the syringe, silicone oil and a susceptible drug may cause non-infectious endophthalmitis after intravitreal injections.2
However, we have to disagree with two other comments by the authors. Firstly, we employed two complementary techniques of assessing the presence of silicone oil from the syringes: light microscopy and Fourier-transform infrared spectroscopy.3-5 While the former allowed us to state that agitation of the syringe leads to a much higher release of silicone oil droplets with consistent and reproducible data, the latter showed that all models analysed have silicone oil in their interior, except for the oil-free one. Additionally, although it seems more reasonable, the use of a staining method might yield false-positivity, as we saw in our preliminary study.4
Secondly, we believe that flushing the syringes with saline before drawing the drug...
Dear editor, we received with interest the comments by Wambier et al.1 They provided interestingly new insights in possible adverse effects of silicone oil on the human body. If enlarged lymph nodes and skin nodules assumed as sarcoidosis, and lumps in the abdomen of diabetic patients diagnosed as insulin fat hypertrophy are proved to be secondary to the silicone oil released by the syringes, a remarkable paradigm shift will be achieved. Incidentally, the idea of an inflammatory/immunological association to the presence of silicone oil droplets is in agreement with our yet unproven hypothesis that agitation of the syringe, silicone oil and a susceptible drug may cause non-infectious endophthalmitis after intravitreal injections.2
However, we have to disagree with two other comments by the authors. Firstly, we employed two complementary techniques of assessing the presence of silicone oil from the syringes: light microscopy and Fourier-transform infrared spectroscopy.3-5 While the former allowed us to state that agitation of the syringe leads to a much higher release of silicone oil droplets with consistent and reproducible data, the latter showed that all models analysed have silicone oil in their interior, except for the oil-free one. Additionally, although it seems more reasonable, the use of a staining method might yield false-positivity, as we saw in our preliminary study.4
Secondly, we believe that flushing the syringes with saline before drawing the drug introduces an additional risk for bacterial contamination. Since endophthalmitis is a vision-threatening condition, any additional step should be avoided.
In conclusion, we advocate that the manufacturers develop syringes previously tested and approved for intraocular use. We also recommend that no agitation of the syringe be performed at the time of intravitreal injections.
1. Wambier CG, Wambier SPF, Beltrame FL. Here is your injection: would you like with or without silicone oil? Br J Ophthalmol. [eLetter] 3 June 2019. https://bjo.bmj.com/content/early/2019/03/24/bjophthalmol-2019-313823.re...
2. Melo GB, Figueira ACM, Batista FAH, Lima Filho AAS, Rodrigues EB, Belfort Jr R, et al. Inflammatory reaction after aflibercept intravitreal injections associated with silicone oil droplets released from syringes: a case-control study. Ophthalmic Surg Lasers Imaging Retina. 2019;50(5):288-294. doi: 10.3928/23258160-20190503-05.
3. Melo GB, Emerson GG, Dias Jr CS, Morais FB, Lima Filho A de S, Ota S, et al. Release of silicone oil and the off-label use of syringes in ophthalmology. Br J Ophthalmol. 2019. doi:10.1136/bjophthalmol-2019-313823.
4. Melo GB, Dias Jr CS, Carvalho MR, Cardoso AL, Morais FB, Figueira ACM, et al. Release of silicone oil from syringes. Int J Retina Vitreous. 2019;5:1.
5. Agra LLM, Melo GB, Lima Filho AAS, Ota S, Maia M. Silicone oil found in syringes commonly used for intravitreal injections. Arq Bras Oftalmol. 2019;82(4):354-5.
We read the study by Vinciguerra et al. on cornea biomechanical properties of open angle glaucoma, ocular hypertension, normal tension and normal eyes assessed with dynamic air-puff applanation [1]. The study reported significant correlations between the properties and types of glaucoma. Most of the study patients were also under anti-glaucoma medication. Interestingly, the study did not assess the potential confounding effects of the anterior chamber on assessment of corneal biomechanical properties [1]. However, we wish to bring to the notice of the authors our earlier study on the same subject [2]. In our study, open and closed angle patients under the anti-glaucoma medication were assessed with air-puff applanation to determine if medication altered corneal biomechanical properties. The highlight of the study was that anterior chamber depth (ACD) was also included as a covariate in addition to other tomographic features [2]. Our study clearly showed that the ACD had a significant effect of the level of bIOP among the different types of glaucoma patient [2]. The ACD is a direct indicator of the volume of vault space between the cornea and the lens. This vault space resisted the inward motion of the cornea during the first half of the applanation. If ACD was lower, then bIOP was greater and vice versa. In patients with angle closure glaucoma, we expect the ACD to be less than NTG and normal eyes [1,2]. Hence, the results from the Vinciguerra et al. study could be skewed...
We read the study by Vinciguerra et al. on cornea biomechanical properties of open angle glaucoma, ocular hypertension, normal tension and normal eyes assessed with dynamic air-puff applanation [1]. The study reported significant correlations between the properties and types of glaucoma. Most of the study patients were also under anti-glaucoma medication. Interestingly, the study did not assess the potential confounding effects of the anterior chamber on assessment of corneal biomechanical properties [1]. However, we wish to bring to the notice of the authors our earlier study on the same subject [2]. In our study, open and closed angle patients under the anti-glaucoma medication were assessed with air-puff applanation to determine if medication altered corneal biomechanical properties. The highlight of the study was that anterior chamber depth (ACD) was also included as a covariate in addition to other tomographic features [2]. Our study clearly showed that the ACD had a significant effect of the level of bIOP among the different types of glaucoma patient [2]. The ACD is a direct indicator of the volume of vault space between the cornea and the lens. This vault space resisted the inward motion of the cornea during the first half of the applanation. If ACD was lower, then bIOP was greater and vice versa. In patients with angle closure glaucoma, we expect the ACD to be less than NTG and normal eyes [1,2]. Hence, the results from the Vinciguerra et al. study could be skewed because of variation in ACD of the study patients. We highly encourage the authors to reanalyze their data after including ACD as a co-variate in the generalized linear models [1].
References
1. Vinciguerra R, Rehman S, Vallabh NA, et al. Corneal biomechanics and biomechanically corrected intraocular pressure in primary open-angle glaucoma, ocular hypertension and controls. Br J Ophthalmol. 2019; In press.
2. Tejwani S, Francis M, Dinakaran S, et al. Influence of Anterior Biometry on Corneal Biomechanical Stiffness of Glaucomatous Eyes Treated with Chronic Medication or Filtration Surgery. J Glaucoma. 2019;28:626-632.
Editor,
We read with great interest the article titled “Choroidal thickness and vascular density in macular telangiectasia type 2 using en face swept-source optical coherence tomography” by Wang et al.[1] This is an interesting study in which the authors performed multimodal imaging for the diagnosis of macular telangiectasia (MacTel) type 2 and reported similar choroidal thickness (CT) between MacTel type 2 and control eyes using swept-source optical coherence tomography (SS-OCT).[1]
There are a few concerns that we would like to highlight. Although the authors control for confounders like age and spherical equivalent, axial length is another important confounder that has not been evaluated in this prospectively conducted study. The subfoveal CT has been reported to decrease by up to 58µm per one mm increase in the axial length after adjusting for age and sex.[2] Ignoring the axial length in choroidal thickness analysis may have untoward consequences.
Although the number of cases was small (n=39 eyes), the stagewise distribution of CT may be of help. A recent study by Kumar et al. using SS-OCT reported different subfoveal CT in non-proliferative and proliferative stages of the disease, although the results were not statistically significant.[3] If a varied distribution is observed between different stages, this may support the role of the choroid in the pathophysiology of this disease.
Inter-ocular asymmetry does exist in CT[4] as well as in the pr...
Editor,
We read with great interest the article titled “Choroidal thickness and vascular density in macular telangiectasia type 2 using en face swept-source optical coherence tomography” by Wang et al.[1] This is an interesting study in which the authors performed multimodal imaging for the diagnosis of macular telangiectasia (MacTel) type 2 and reported similar choroidal thickness (CT) between MacTel type 2 and control eyes using swept-source optical coherence tomography (SS-OCT).[1]
There are a few concerns that we would like to highlight. Although the authors control for confounders like age and spherical equivalent, axial length is another important confounder that has not been evaluated in this prospectively conducted study. The subfoveal CT has been reported to decrease by up to 58µm per one mm increase in the axial length after adjusting for age and sex.[2] Ignoring the axial length in choroidal thickness analysis may have untoward consequences.
Although the number of cases was small (n=39 eyes), the stagewise distribution of CT may be of help. A recent study by Kumar et al. using SS-OCT reported different subfoveal CT in non-proliferative and proliferative stages of the disease, although the results were not statistically significant.[3] If a varied distribution is observed between different stages, this may support the role of the choroid in the pathophysiology of this disease.
Inter-ocular asymmetry does exist in CT[4] as well as in the presentation of MacTel.[3,5] Although a significant inter-ocular difference in subfoveal CT may not exist, the reported difference reaches up to 85µm with thicker choroid in the right eyes.[4] It may be useful to compare the right and left eyes separately. The authors used multilevel mixed effect linear regression as both eyes of the patients were included.[1] However, there may exist a difference in the stage of disease among the fellow eyes, and the fellow eyes may be studied separately.[3,5] The comparison of disease characteristics between the fellow eyes may, therefore, be important.
References
1 Wang JC, Laíns I, Oellers P, et al. Choroidal thickness and vascular density in macular telangiectasia type 2 using enface swept-source optical coherence tomography. Br J Ophthalmol Published Online First: 2 January 2019. doi:10.1136/bjophthalmol-2018-313414
2 Li XQ, Larsen M, Munch IC. Subfoveal choroidal thickness in relation to sex and axial length in 93 Danish university students. Invest Ophthalmol Vis Sci 2011;52:8438–41. doi:10.1167/iovs.11-8108
3 Kumar V, Kumawat D, Kumar P. Swept source optical coherence tomography analysis of choroidal thickness in macular telangiectasia type 2: a case-control study. Graefes Arch Clin Exp Ophthalmol Albrecht Von Graefes Arch Klin Exp Ophthalmol Published Online First: 17 December 2018. doi:10.1007/s00417-018-04215-9
4 Chen FK, Yeoh J, Rahman W, et al. Topographic variation and interocular symmetry of macular choroidal thickness using enhanced depth imaging optical coherence tomography. Invest Ophthalmol Vis Sci 2012;53:975–85. doi:10.1167/iovs.11-8771
5 Bruè C, Tseng JJ, Barbazetto I, et al. PECULIAR MANIFESTATION OF MACULAR TELANGIECTASIA TYPE 2. Retin Cases Brief Rep 2011;5:309. doi:10.1097/ICB.0b013e3181f66b8c
We appreciate the interest in our paper by Kumawat and Kumar, and the opportunity to address their comments. With regards to axial length, it is certainly known to be correlated with choroidal thickness. However, this information was not routinely obtained in our retina clinic and was not available for most patients in the study. We were able to account for spherical equivalent in our multivariate model, which may serve as a proxy for axial length. We agree that accounting for at least one of these variables is required for studies on choroidal thickness. We appreciate the Kumawat and Kumar’s suggestion to categorize patients based on stage of disease (proliferative vs nonproliferative). We had considered this approach, however the small number of patients with proliferative disease (only 4) made this less ideal from a statistical standpoint. Subretinal neovascularization was included in our univariate analysis but was not found to be statistically significant with regard to choroidal thickness, so it was not further considered in our multivariate assessments. Lastly, while inter-ocular asymmetry in choroidal thickness may exist, eye laterality was not found to be a significant variable affecting choroidal thickness in our univariate analysis (p = 0.87) and thus was also not included in multivariate models. We once again thank Dr. Kumawat and Dr. Kumar for their interest in our work.
I read with interest and appreciate the article by Choi et al 1 on 'Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients'.
As the study looks at the IOP changes after intravitreal dexamethasone implant, how the IOP was recorded for the patients is very important. The authors have reported that the intraocular pressure (IOP) was measured by non-contact tonometer (NCT) or Goldmann applanation tonometry (GAT) in this study. First, it is not mentioned as to which NCT was used for IOP measurement. If NCT was used to measure pre-injection IOP, was it used to measure post-injection IOP measurement also? Or on different visits IOP recording was done with NCT or GAT, is not clear. As GAT is still considered as a gold standard for IOP measurement, if IOP on NCT is found to be high, ideally it should be rechecked with GAT. Second, it is not mentioned whether a single IOP measurement was taken or multiple IOP measurements were obtained, taking the average value as the final IOP. Third, a s the lower range of age was 16 years (Table 1), was there any correlation of IOP change after the injection with the age?
Reference
1. Choi W, Park SE, Kang HG et al. Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients. Br J Ophthalmol 2018. Epub ahead
of print. doi:10.1136/ bjophthalmol-2018-312958
I read with great interest the paper titled “Collateral vessels on optical coherence tomography (OCT) angiography in eyes with branch retinal vein occlusion (BRVO)” by Suzuki et al.1
The authors defined collateral vessels as dilated and tortuous capillaries occurring in pre-existing capillary beds and linking the obstructed vessel with the nearest patent vessel, according to previous reports.2-4 The authors demonstrated that collaterals were detected in 23 out of 28 (82%) eyes, all of which already existed at mean 0.95 months after the onset, and that all of the collaterals were observed in both the retinal superficial and the deep layers.
However, some of the vessels which are pointed out as collaterals in the study1 look like simply dilated/tortuous vessels, because they don’t seem to connect obstructed to non-obstructed adjacent vessels nor by-pass obstructions. In a previous report, the authors found collateral vessels in 18 out of 28 (64%) eyes at mean 25.1 months from the onset, while superficial and deep capillary telangiectasias were detected in 13 and 28 out of 28 eyes, respectively.4 Therefore, I suppose that some of the vessels defined as collaterals in this study1 may be simply telangiectasias.
Fruend et al.5 defined collateral vessels as the authors did. After excluding collaterals involving the perifoveal vascular ring, they demonstrated that collaterals were found in 23 out of 23 eyes (100%) at median time of 3.79 years from RVO...
I read with great interest the paper titled “Collateral vessels on optical coherence tomography (OCT) angiography in eyes with branch retinal vein occlusion (BRVO)” by Suzuki et al.1
The authors defined collateral vessels as dilated and tortuous capillaries occurring in pre-existing capillary beds and linking the obstructed vessel with the nearest patent vessel, according to previous reports.2-4 The authors demonstrated that collaterals were detected in 23 out of 28 (82%) eyes, all of which already existed at mean 0.95 months after the onset, and that all of the collaterals were observed in both the retinal superficial and the deep layers.
However, some of the vessels which are pointed out as collaterals in the study1 look like simply dilated/tortuous vessels, because they don’t seem to connect obstructed to non-obstructed adjacent vessels nor by-pass obstructions. In a previous report, the authors found collateral vessels in 18 out of 28 (64%) eyes at mean 25.1 months from the onset, while superficial and deep capillary telangiectasias were detected in 13 and 28 out of 28 eyes, respectively.4 Therefore, I suppose that some of the vessels defined as collaterals in this study1 may be simply telangiectasias.
Fruend et al.5 defined collateral vessels as the authors did. After excluding collaterals involving the perifoveal vascular ring, they demonstrated that collaterals were found in 23 out of 23 eyes (100%) at median time of 3.79 years from RVO diagnosis or initial visit, and that all collaterals were primarily located within the deep vascular complex. Indeed there are differences in patients’ and ocular backgrounds between the two studies.1,5 But the findings about the location of collaterals by Fruend et al5 may support my supposition that some of the vessels defined as collaterals in this study1 are simply telangiectasias.
I hope that the authors will comment on this point.
References
1. Suzuki N, Hirano Y, Tomiyasu T, et al. Collateral vessels on optical coherence tomography angiography in eyes with branch retinal vein occlusion. Br J Ophthalmol (in press).
2. Klein R, Klein B, Henkind P, et al. Retinal collateral vessel formation. Invest Ophthalmol 1971;10:471-80.
3. Christoffersen NL, Larsen M. Pathophysiology and hemodynamics of branch retinal vein occlusion. Ophthalmology 1999;106:2054-62.
4. Suzuki N, Hirano Y, Yoshida M, et al. Microvascular abnormalities on optical coherence tomography angiography in macular edema associated with branch retinal vein occlusion. Am J Ophthalmol 2016;161:126-32.
5. Freund KB, Sarraf D, Leong BCS, et al. Association of optical coherence tomography angiography of collaterals in retinal vein occlusion with major venous outflow through the deep vascular complex. JAMA Ophthalmology 2018;136:1262-70.
To,
Show MoreThe editor
We would like to congratulate Huang et al. for their study ‘Combined subconjunctival injection of dexamethasone for the management of acute primary angle closure: a randomised controlled trial’.1 However, we have few queries and seek your kind attention.
First, as mentioned in this article, a previous study in dogs showed combination of topical anti-inflammatory eye drops was beneficial during treatment.2They had conducted this present study as there was no data on humans regarding a randomised controlled trial that demonstrates the effectiveness of anti-inflammatory drugs for the treatment of human eyes suffering from acute primary angle closure (APAC). However, as the title suggested combination of subconjunctival dexamethasone injection, it implied combination of it with other anti-inflammatory drugs. However, the injection group was not subjected to any other anti-inflammatory drugs.
Second, the authors’ previous study showed that the inflammatory response in the aqueous humor from APAC patient was evident and that multiple inflammatory factors were elevated significantly.3 Topical steroids help to reduce intraocular inflammation make the patient more comfortable.4 However; the control group was not subjected to any topical anti-inflammatory drug.
Third, we are interested to know about the range of intraocular pressure (IOP) in those 42 eyes; the highest and lowest IOP recorded.
Fourth, we are also interested to know r...
Dear Editor,
Show MoreWith great interest, we have read the article by Feihui et al.[1]
This study has investigated the sensitivities and specificities of different diagnostic criteria based on the OCT for glaucoma detection. According to the article abnormal superotemporal and inferotemporal RNFLT attained a higher sensitivity than abnormal superotemporal and inferotemporal BMO-MRW to detect mild glaucoma. However, our query arises when “Integration of RNFLT / BMO-MRW assessment was done”. The author stated, integrating RNFLT and BMO-MRW assessment did not change the sensitivity and specificity of RNFLT but increased the sensitivity of BMO-MRW for detection of glaucoma. To quote the author, the author paradoxically stated “ Our finding underscores the importance of RNFL imaging and measurement in the diagnostic evaluation of glaucoma”. We are interested to know if sensitivity and specificity on combination is increased, why would the diagonostic performance not increased? Reis et al stated, Bruch's membrane opening minimum rim width (BMO‐MRW) reproducibility were comparable and excellent in both healthy subjects and patients with glaucoma to that of RNFLT measurements.[2]
The article also did not include head tilt in the confounding covariates, as it was previously stated, head tilt significantly affects OCT image orientation as measured by the FoBMO angle.[3]
The article has also not mentioned dimensions of the optic nerve head (ONH) as stated previo...
To the Editor:
We herein respond to the letter written by Camus et al raising the issue of “ultra-low” dose radiation therapy (4 Gy) vs. the “standard low-dose” radiation therapy (24-30 Gy) for lymphomas of the orbit, eyelid, and conjunctiva, also referred to as “ocular adnexal lymphoma” (OAL). First off, it is important to point out that the goals of the retrospective multicenter general review of marginal zone lymphoma coordinated by Professor Steffen Heegaard in Denmark which also included some of our patients from M. D. Anderson was not to compare the efficacy of various treatment strategies.(1) Indeed it is challenging to draw practice altering conclusions from a retrospective multi-center study given the usual limitations, most notably the variation in staging and treatment approaches across various continents as noted by Camus et al.
However, we agree with Camus et al that our encouraging preliminary observations in 22 patients with OAL treated with ultra-low dose radiation therapy (4Gy) suggested a very good response rate (100% ORR:86% CR, 14%% PR) for B-cell orbital and ocular adnexal lymphomas;(2) as such we started a prospective trial of ultra-low dose radiation for ocular adnexal lymphoma patients at MD Anderson Cancer Center soon thereafter (Clinicaltrials.gov identifier NCT02494700)The study aims to evaluate the efficacy of response adapted radiation therapy for this patient population, whereby all patients are treated to an initial 4 Gy in...
Show MoreDear editor, we have read with great interest the article presented by Melo et al.1 The authors provide good evidence of silicone oil release in injections from lubricated syringes. However, the likelihood of false-negative data may have been high because of lack of a staining method (Sudan III, for example) to differentiate and highlight small droplets, as previously described.2
Although injectable fluid contamination with syringe silicone oil has been known for decades,3,4 the lack of awareness of all medical specialties about this problem is impressive. The most concerning, still controversial long-term effect of silicone oil exposure is the development of an autoimmune/inflammatory syndrome induced by adjuvants, also known as ASIA syndrome.5
Given the massive amount of injections given worldwide, silicone oil injected seems safer than one would imagine, however, it is worth remembering that if the physician is unaware of the fact of the silicone oil injection, the diagnosis is omitted as a possible hypothesis. Enlarged lymph nodes or skin nodules with evidence of granulomas are assumed as sarcoidosis, and lumps in the abdomen of diabetic patients are all diagnosed as insulin fat hypertrophy, and if a biopsy is performed, the likely cause of the granuloma would be the injected therapeutic protein or an autoimmune phenomenon. If the physicians are informed that a patient received silicone oil injections the diagnoses change to silicone oil induced granuloma...
Show MoreDear editor, we received with interest the comments by Wambier et al.1 They provided interestingly new insights in possible adverse effects of silicone oil on the human body. If enlarged lymph nodes and skin nodules assumed as sarcoidosis, and lumps in the abdomen of diabetic patients diagnosed as insulin fat hypertrophy are proved to be secondary to the silicone oil released by the syringes, a remarkable paradigm shift will be achieved. Incidentally, the idea of an inflammatory/immunological association to the presence of silicone oil droplets is in agreement with our yet unproven hypothesis that agitation of the syringe, silicone oil and a susceptible drug may cause non-infectious endophthalmitis after intravitreal injections.2
Show MoreHowever, we have to disagree with two other comments by the authors. Firstly, we employed two complementary techniques of assessing the presence of silicone oil from the syringes: light microscopy and Fourier-transform infrared spectroscopy.3-5 While the former allowed us to state that agitation of the syringe leads to a much higher release of silicone oil droplets with consistent and reproducible data, the latter showed that all models analysed have silicone oil in their interior, except for the oil-free one. Additionally, although it seems more reasonable, the use of a staining method might yield false-positivity, as we saw in our preliminary study.4
Secondly, we believe that flushing the syringes with saline before drawing the drug...
We read the study by Vinciguerra et al. on cornea biomechanical properties of open angle glaucoma, ocular hypertension, normal tension and normal eyes assessed with dynamic air-puff applanation [1]. The study reported significant correlations between the properties and types of glaucoma. Most of the study patients were also under anti-glaucoma medication. Interestingly, the study did not assess the potential confounding effects of the anterior chamber on assessment of corneal biomechanical properties [1]. However, we wish to bring to the notice of the authors our earlier study on the same subject [2]. In our study, open and closed angle patients under the anti-glaucoma medication were assessed with air-puff applanation to determine if medication altered corneal biomechanical properties. The highlight of the study was that anterior chamber depth (ACD) was also included as a covariate in addition to other tomographic features [2]. Our study clearly showed that the ACD had a significant effect of the level of bIOP among the different types of glaucoma patient [2]. The ACD is a direct indicator of the volume of vault space between the cornea and the lens. This vault space resisted the inward motion of the cornea during the first half of the applanation. If ACD was lower, then bIOP was greater and vice versa. In patients with angle closure glaucoma, we expect the ACD to be less than NTG and normal eyes [1,2]. Hence, the results from the Vinciguerra et al. study could be skewed...
Show MoreEditor,
Show MoreWe read with great interest the article titled “Choroidal thickness and vascular density in macular telangiectasia type 2 using en face swept-source optical coherence tomography” by Wang et al.[1] This is an interesting study in which the authors performed multimodal imaging for the diagnosis of macular telangiectasia (MacTel) type 2 and reported similar choroidal thickness (CT) between MacTel type 2 and control eyes using swept-source optical coherence tomography (SS-OCT).[1]
There are a few concerns that we would like to highlight. Although the authors control for confounders like age and spherical equivalent, axial length is another important confounder that has not been evaluated in this prospectively conducted study. The subfoveal CT has been reported to decrease by up to 58µm per one mm increase in the axial length after adjusting for age and sex.[2] Ignoring the axial length in choroidal thickness analysis may have untoward consequences.
Although the number of cases was small (n=39 eyes), the stagewise distribution of CT may be of help. A recent study by Kumar et al. using SS-OCT reported different subfoveal CT in non-proliferative and proliferative stages of the disease, although the results were not statistically significant.[3] If a varied distribution is observed between different stages, this may support the role of the choroid in the pathophysiology of this disease.
Inter-ocular asymmetry does exist in CT[4] as well as in the pr...
Dear Editor,
We appreciate the interest in our paper by Kumawat and Kumar, and the opportunity to address their comments. With regards to axial length, it is certainly known to be correlated with choroidal thickness. However, this information was not routinely obtained in our retina clinic and was not available for most patients in the study. We were able to account for spherical equivalent in our multivariate model, which may serve as a proxy for axial length. We agree that accounting for at least one of these variables is required for studies on choroidal thickness. We appreciate the Kumawat and Kumar’s suggestion to categorize patients based on stage of disease (proliferative vs nonproliferative). We had considered this approach, however the small number of patients with proliferative disease (only 4) made this less ideal from a statistical standpoint. Subretinal neovascularization was included in our univariate analysis but was not found to be statistically significant with regard to choroidal thickness, so it was not further considered in our multivariate assessments. Lastly, while inter-ocular asymmetry in choroidal thickness may exist, eye laterality was not found to be a significant variable affecting choroidal thickness in our univariate analysis (p = 0.87) and thus was also not included in multivariate models. We once again thank Dr. Kumawat and Dr. Kumar for their interest in our work.
I read with interest and appreciate the article by Choi et al 1 on 'Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients'.
As the study looks at the IOP changes after intravitreal dexamethasone implant, how the IOP was recorded for the patients is very important. The authors have reported that the intraocular pressure (IOP) was measured by non-contact tonometer (NCT) or Goldmann applanation tonometry (GAT) in this study. First, it is not mentioned as to which NCT was used for IOP measurement. If NCT was used to measure pre-injection IOP, was it used to measure post-injection IOP measurement also? Or on different visits IOP recording was done with NCT or GAT, is not clear. As GAT is still considered as a gold standard for IOP measurement, if IOP on NCT is found to be high, ideally it should be rechecked with GAT. Second, it is not mentioned whether a single IOP measurement was taken or multiple IOP measurements were obtained, taking the average value as the final IOP. Third, a s the lower range of age was 16 years (Table 1), was there any correlation of IOP change after the injection with the age?
Reference
1. Choi W, Park SE, Kang HG et al. Intraocular pressure change after injection of intravitreal dexamethasone (Ozurdex) implant in Korean patients. Br J Ophthalmol 2018. Epub ahead
of print. doi:10.1136/ bjophthalmol-2018-312958
I read with great interest the paper titled “Collateral vessels on optical coherence tomography (OCT) angiography in eyes with branch retinal vein occlusion (BRVO)” by Suzuki et al.1
Show MoreThe authors defined collateral vessels as dilated and tortuous capillaries occurring in pre-existing capillary beds and linking the obstructed vessel with the nearest patent vessel, according to previous reports.2-4 The authors demonstrated that collaterals were detected in 23 out of 28 (82%) eyes, all of which already existed at mean 0.95 months after the onset, and that all of the collaterals were observed in both the retinal superficial and the deep layers.
However, some of the vessels which are pointed out as collaterals in the study1 look like simply dilated/tortuous vessels, because they don’t seem to connect obstructed to non-obstructed adjacent vessels nor by-pass obstructions. In a previous report, the authors found collateral vessels in 18 out of 28 (64%) eyes at mean 25.1 months from the onset, while superficial and deep capillary telangiectasias were detected in 13 and 28 out of 28 eyes, respectively.4 Therefore, I suppose that some of the vessels defined as collaterals in this study1 may be simply telangiectasias.
Fruend et al.5 defined collateral vessels as the authors did. After excluding collaterals involving the perifoveal vascular ring, they demonstrated that collaterals were found in 23 out of 23 eyes (100%) at median time of 3.79 years from RVO...
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