Chan et al report on marked elevations in serum IgG2 that are observed in patients with orbital IgG4 related disease (IgG4-RD), with or without systemic involvement.
Using ROC area under the curve comparisons, the authors show that the serum IgG2 concentration has a higher AUC (0.9) than serum IgG4 (0.8) in detecting IgG4-RD in their cohort (comprised of 33 subjects: 20 with orbital IgG4-RD with or without systemic involvement, and 13 with non-IgG4-RD orbital inflammation).
Our group has noted this paper by Chan et al with interest as we have observed the same phenomenon of marked serum IgG2 elevations in patients with IgG4-RD, who have concomitantly low serum IgG4 concentrations. Like the patients presented by Chan et al, our IgG4-RD patients uniformly had serum IgG2 concentrations that were greater than the serum IgG4 concentration, even when the serum IgG4 concentration was very high.
Our interpretation of the apparent superior clinical utility of the serum IgG2 test in this context, is that this observation is only made when using an immunonephelometric methodology subject to two different types of analytical error:
i) antigen excess, leading to falsely low serum IgG4 measurement in a patient who in fact has a marked elevation of serum IgG4 [2] and
ii) cross reactivity of the reagent used to measure IgG2 with serum IgG4, leading to falsely high serum IgG2 measurement (this may be due to a direct and specific recognition of IgG4 epitop...
Chan et al report on marked elevations in serum IgG2 that are observed in patients with orbital IgG4 related disease (IgG4-RD), with or without systemic involvement.
Using ROC area under the curve comparisons, the authors show that the serum IgG2 concentration has a higher AUC (0.9) than serum IgG4 (0.8) in detecting IgG4-RD in their cohort (comprised of 33 subjects: 20 with orbital IgG4-RD with or without systemic involvement, and 13 with non-IgG4-RD orbital inflammation).
Our group has noted this paper by Chan et al with interest as we have observed the same phenomenon of marked serum IgG2 elevations in patients with IgG4-RD, who have concomitantly low serum IgG4 concentrations. Like the patients presented by Chan et al, our IgG4-RD patients uniformly had serum IgG2 concentrations that were greater than the serum IgG4 concentration, even when the serum IgG4 concentration was very high.
Our interpretation of the apparent superior clinical utility of the serum IgG2 test in this context, is that this observation is only made when using an immunonephelometric methodology subject to two different types of analytical error:
i) antigen excess, leading to falsely low serum IgG4 measurement in a patient who in fact has a marked elevation of serum IgG4 [2] and
ii) cross reactivity of the reagent used to measure IgG2 with serum IgG4, leading to falsely high serum IgG2 measurement (this may be due to a direct and specific recognition of IgG4 epitopes, or to non-specific “novel rheumatoid factor” interaction) [3, 4].
Both types of error are directly mediated by the magnitude of the serum IgG4 concentration, and therefore distort the diagnostic utility of both serum IgG2 (falsely increased diagnostic accuracy) and serum IgG4 (falsely decreased diagnostic accuracy) for IgG4-RD. In order, to fairly compare the two serum biomarkers, it is necessary to use a methodology, such as mass spectrometry, which is impervious to both types of error [4].
As the serum biomarker measurement methodology was not specified in the Chan paper, and some testing was performed as early as 2002, when the error of antigen excess in this circumstance had not yet been reported in the literature, there is a high probability that both types of error affected their results. Therefore, we question the implications that were derived from their observations. Given consideration to updated information on the measurement of IgG subclasses [4], we interpret the presented serum findings as representative of analytic artifact and consider serum IgG4 to be the preferred biomarker for IgG4-RD.
References
1. Chan ASY, Mudhar H, Shen SY, Lang SS, Fernando M, Hilmy MH, et al. Serum IgG2 and tissue IgG2 plasma cell elevation in orbital IgG4-related disease (IgG4-RD): Potential use in IgG4-RD assessment. Br J Ophthalmol 2017;101(11):1576-82.
2. Khosroshahi A, Cheryk LA, Carruthers MN, Edwards JA, Bloch DB, Stone JH. Brief report: Spuriously low serum IgG4 concentrations caused by the prozone phenomenon in patients with IgG4-related disease. Arthritis Rheumatol 2014;66(1):213-7.
3. Ito T, Kitahara K, Umemura T, Ota M, Shimozuru Y, Kawa S, et al. A novel heterophilic antibody interaction involves IgG4. Scand J Immunol 2010;71(2):109-14.
4. van der Gugten G, DeMarco ML, Chen LYC, Chin A, Caruthers M, Holmes DT, et al. Resolution of spurious immunonephelometric IgG subclass measurement discrepancies by LC-MS/MS. Clinical Chemistry 2018 (in press).
The article in question：
Crewe JM, Threlfall T, Clark A, Sanfilippo PG, Mackey DA. Pterygia are indicators of an increased risk of developing cutaneous melanomas. Br J Ophthalmol 2017.
Authors:
Jingjing Shen
Minqian Shen
Yuanzhi Yuan
Corresponding author:
Yuanzhi Yuan
Address：#180 Fenglin Rd., Department of Ophthalmology, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P.R. China
Email: yuan.yuanzhi@zs.hospital.sh.cn
Phone: +86-186 1688 1220 or +86-21-64041990 ext. 2684
Dear Editor,
We read with great interest the paper by Crewe et al.1 The authors showed that patients with pterygium had higher risk of cutaneous melanomas (CM) in a large retrospective matched-cohort study in Western Australia (WA), and suggested pterygium as an indicator for CM. The finding was interesting. However, we doubt the conclusion and its clinical relevance and public health significance.
Compared to control group, patients with pterygium had a 20% or 24% increased risk of developing CM in terms of odds ratio(OR) or incidence rate ratio (IRR), respectively. The incidence rate difference（IRD）, however, was only 27.7/100 000 person-years (PY) (Table 5., by subtracting the IR of the control group from that of the pterygium group, i.e. (186.5-158.8)/100 000 PY). The rate difference corres...
The article in question：
Crewe JM, Threlfall T, Clark A, Sanfilippo PG, Mackey DA. Pterygia are indicators of an increased risk of developing cutaneous melanomas. Br J Ophthalmol 2017.
Authors:
Jingjing Shen
Minqian Shen
Yuanzhi Yuan
Corresponding author:
Yuanzhi Yuan
Address：#180 Fenglin Rd., Department of Ophthalmology, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P.R. China
Email: yuan.yuanzhi@zs.hospital.sh.cn
Phone: +86-186 1688 1220 or +86-21-64041990 ext. 2684
Dear Editor,
We read with great interest the paper by Crewe et al.1 The authors showed that patients with pterygium had higher risk of cutaneous melanomas (CM) in a large retrospective matched-cohort study in Western Australia (WA), and suggested pterygium as an indicator for CM. The finding was interesting. However, we doubt the conclusion and its clinical relevance and public health significance.
Compared to control group, patients with pterygium had a 20% or 24% increased risk of developing CM in terms of odds ratio(OR) or incidence rate ratio (IRR), respectively. The incidence rate difference（IRD）, however, was only 27.7/100 000 person-years (PY) (Table 5., by subtracting the IR of the control group from that of the pterygium group, i.e. (186.5-158.8)/100 000 PY). The rate difference corresponds to a number needed to harm (NNH) of 3610 (the reciprocal of the rate difference), which means that if 3610 individuals with pterygium that needed to be excised are followed for one year, approximately one additional CM could be detected. However, the annual cases of pterygium treatment in WA were less than 1/3 of this NNH value (figure 2; around 1000 pterygium cases were treated in WA hospitals in 2013) 1. In other words, only one person could gain benefit if all cases of pterygium treatment in WA be carefully followed up for more than 3 years. It could potentially result in unnecessary biopsies, lead to overdiagnosis and overtreatment, and cause enormous waste of resources,2 not to mention the considerable anxiety exposed to the patients and their relatives year by year.
Giving the strategy of the exposure group (the patients with pterygium) sampling, there was obvious selection bias in Crewe’s study. The reported population prevalence of pterygium varies from 2.8% to 7.8% in Australia.3-5 But only the cases with hospital treated pterygium were included in the study, which overrepresented the serious pterygium cases with higher cumulative risk of ultraviolet radiation exposure, thus may be predisposed to CM. On the other hand, patients may have their pterygia removed for cosmetic reasons. An increased detection rate for CM could also be observed in such patients as they might be alert to any changes of their appearance. Thus, the selection of the exposure group in this cohort study could falsely increase the association between pterygium and CM. As acknowledged in the paper, only a small proportion of pterygium cases were included in the study. If, however, the potentially biased conclusion be extrapolated to general pterygium cases, it could do even more harm than good.
A real-world study with big data is appealing because of its representation of the wider population. However, even a small effect, if any, can be statistically significant with a large sample size. Caution should especially be taken in interpreting the findings and their clinical relevance and significance.
Moreover, a typo in Table 5 needs to be corrected. The age groups should be labeled as “>50 years” and “<49 years.”
1. Zhongshan Hospital Affiliated to Fudan University
2. Center for Evidence-based Medicine, Fudan University
Financial Disclosures: The authors have no financial disclosures.
Reference:
1. Crewe JM, Threlfall T, Clark A, Sanfilippo PG, Mackey DA. Pterygia are indicators of an increased risk of developing cutaneous melanomas. Br J Ophthalmol 2017.
2. Force USPST, Bibbins-Domingo K, Grossman DC, et al. Screening for Skin Cancer: US Preventive Services Task Force Recommendation Statement. JAMA 2016;316(4):429-35.
3. Pham TQ, Wang JJ, Rochtchina E, Mitchell P. Pterygium, pinguecula, and 5-year incidence of cataract. Am J Ophthalmol 2005;139(6):1126-8.
4. Landers J, Henderson T, Craig J. Prevalence of pterygium in indigenous Australians within central Australia: the Central Australian Ocular Health Study. Clin Exp Ophthalmol 2011;39(7):604-6.
5. McCarty CA, Fu CL, Taylor HR. Epidemiology of pterygium in Victoria, Australia. Br J Ophthalmol 2000;84(3):289-92.
We read with interest the insightful comments in the e-letter submitted by Dr. Gain, Dr. He, Dr. Garcin, and Dr. Thuret on our recently published article.1 As stated in their letter, they previously reported that by using a similar triple staining (i.e., Hoechst 33342, ethidium homodimere and calcein-AM) on the endothelium of whole donor corneas stored in long-term organ culture, the endothelial cell (EC) density in the whole pool of viable ECs in the cornea is routinely, and quite substantially, overestimated.2,3 We completely agree with the authors regarding the importance of assessing the whole pool of viable ECs in corneal grafts.
We first reported at the 2009 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) that triple-staining a donor graft with propidium iodide, calcein-AM, and Hoechst 33342 allowed for a distinct discrimination between living cells and dead cells. In that report, we hypothesized that the existence of dead cells on the endothelium of the donor cornea suggests an association with the rapid loss of corneal ECs, at least at the early phase, post keratoplasty. However, Gauthier and associates reported3 that there was no difference between the density of viable ECs at day 0 and at day 5 postoperative, thus suggesting that very early EC loss in the host recipient is almost negligible. However, similar to Gain and associates, we believed that it was quite important to measure viable ECD, not to calculate just ECD by...
We read with interest the insightful comments in the e-letter submitted by Dr. Gain, Dr. He, Dr. Garcin, and Dr. Thuret on our recently published article.1 As stated in their letter, they previously reported that by using a similar triple staining (i.e., Hoechst 33342, ethidium homodimere and calcein-AM) on the endothelium of whole donor corneas stored in long-term organ culture, the endothelial cell (EC) density in the whole pool of viable ECs in the cornea is routinely, and quite substantially, overestimated.2,3 We completely agree with the authors regarding the importance of assessing the whole pool of viable ECs in corneal grafts.
We first reported at the 2009 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) that triple-staining a donor graft with propidium iodide, calcein-AM, and Hoechst 33342 allowed for a distinct discrimination between living cells and dead cells. In that report, we hypothesized that the existence of dead cells on the endothelium of the donor cornea suggests an association with the rapid loss of corneal ECs, at least at the early phase, post keratoplasty. However, Gauthier and associates reported3 that there was no difference between the density of viable ECs at day 0 and at day 5 postoperative, thus suggesting that very early EC loss in the host recipient is almost negligible. However, similar to Gain and associates, we believed that it was quite important to measure viable ECD, not to calculate just ECD by using specular microscope.
In our reported case series, we assessed the relationship between the number of dead cells and the EC density post surgery, in both the early phase and late phase post keratoplasty, as it possibly affects the longevity of the cells over the long-term follow-up. We are currently conducting further investigation on this matter.
References
1. Kitazawa K, Inatomi T, Tanioka H, et al. The existence of dead cells in donor corneal endothelium preserved with storage media. Br J Ophthalmol. 2017;101:1725-1730.
2. Pipparelli A, Thuret G, Toubeau D, et al. Pan-corneal endothelial viability assessment: application to endothelial grafts predissected by eye banks. Invest Ophthalmol Vis Sci. 2011;52:6018-6025.
3. Gauthier AS, Garcin T, Thuret G, et al. Very early endothelial cell loss after penetrating keratoplasty with organ-cultured corneas. Br J Ophthalmol. 2017;101:1113-1118.
We noticed the article entitled “The existence of dead cells in donor corneal endothelium preserved with storage media” by Kitazawa with interest (Br J Ophthalmol 2017. Oct 5).
Authors clearly demonstrated, using a triple staining with Hoechst, Propidium Iodide and Calcein-AM, that corneas stored at 4°C in Optisol-GS for 3 to 7 days, the technic most used worldwide, bear a significant number of dead endothelial cells (ECs). They underlined that these non-viable ECs are not recognized by specular cell count done by the eye bank and that this could explain the “cell loss” inevitably noticed post graft. Our team applied, for the first time in 2011 [1] and again in 2016 [2], a similar triple staining on the endothelium of whole corneas stored in long-term organ culture at 31°C, the dominant technic in Europe. We made the same findings as Kitazawa et al. and defined the notion of viable ECD (vECD) as the number of viable ECs per surface unit. Areas without ECs (especially in Descemetic folds), dead and dying EC (that will not survive the storage) clearly explain the important discrepancy between the cell count done by the eye bank (unable to spot them) and the very early postoperative ECD. Our team also demonstrated long ago that vital Trypan blue staining used by certain eye bank is unable to spot all dying cells because its time window of positivity is very narrow, corresponding only to ECs near to desquamate [3]. Viable ECD determined by triple staining therefore appea...
We noticed the article entitled “The existence of dead cells in donor corneal endothelium preserved with storage media” by Kitazawa with interest (Br J Ophthalmol 2017. Oct 5).
Authors clearly demonstrated, using a triple staining with Hoechst, Propidium Iodide and Calcein-AM, that corneas stored at 4°C in Optisol-GS for 3 to 7 days, the technic most used worldwide, bear a significant number of dead endothelial cells (ECs). They underlined that these non-viable ECs are not recognized by specular cell count done by the eye bank and that this could explain the “cell loss” inevitably noticed post graft. Our team applied, for the first time in 2011 [1] and again in 2016 [2], a similar triple staining on the endothelium of whole corneas stored in long-term organ culture at 31°C, the dominant technic in Europe. We made the same findings as Kitazawa et al. and defined the notion of viable ECD (vECD) as the number of viable ECs per surface unit. Areas without ECs (especially in Descemetic folds), dead and dying EC (that will not survive the storage) clearly explain the important discrepancy between the cell count done by the eye bank (unable to spot them) and the very early postoperative ECD. Our team also demonstrated long ago that vital Trypan blue staining used by certain eye bank is unable to spot all dying cells because its time window of positivity is very narrow, corresponding only to ECs near to desquamate [3]. Viable ECD determined by triple staining therefore appears as the only reliable measure of the “useful graft endothelial capital” that is, in our opinion, a major determinant of graft survival. As a reminder, fresh grafts done in the 80’s (that the first author of this e-letter aged over 55 years knows…), contained virtually only viable ECs and were known to have a prolonged survival, around 20-25 years, largely better than the corneas stored today.
Authors conclude that the decreased EC viability may be due partly to the storage conditions. Without pleading for the return of fresh grafts, we are convinced that its improvement will require a profound change in storage process because the two current methods (4 and 31°C) are passive (simple immersion in storage medium). We recently developed the notion of active storage using a corneal bioreactor that restores the intraocular pressure, which is essential for corneal physiology. It naturally limits stromal oedema[4] and significantly improves EC viability[5].
Reference List
1. Pipparelli A, Thuret G, Toubeau D, et al. Pan-corneal endothelial viability assessment: application to endothelial grafts predissected by eye banks. Invest. Ophthalmol. Vis. Sci. 2011;52:6018-25.
2. Gauthier AS, Garcin T, Thuret G, et al. Very early endothelial cell loss after penetrating keratoplasty with organ-cultured corneas. Br J Ophthalmol 2017;101:1113-18.
3. Gain P, Thuret G, Chiquet C, et al. Value of two mortality assessment techniques for organ cultured corneal endothelium: trypan blue versus TUNEL technique. Br J Ophthalmol 2002;86:306-10.
4. Guindolet D, Crouzet E, He Z, et al. Storage of porcine cornea in an innovative bioreactor. Invest. Ophthalmol. Vis. Sci. 2017;in press.
5. Garcin T, Forest F, Verhoeven P, et al. Preclinical randomized controlled study comparing long-term stored human corneas in an innovative bioreactor versus standard organ-culture. Invest. Ophthalmol. Vis. Sci. 2017;58:ARVO E-Abstract 3793.
With great interest, we read the e letter (E-Letter 1) submitted by Ankita Anil Patil, Srikanth Ramsubramanian, and Bipasha Mukherjee, entitled “Comments on article ‘Impact of surgical timing on postoperative ocular motility in orbital blowout fractures’” illustrating their analysis and opinions on our article that was recently published in the British Journal of Ophthalmology. Please know that we greatly appreciate the authors’ cogent and helpful comments.
It should be noted that in our opinion, in order to normalize ocular motility, the most important aspect is to restore the orbital tissues for the appropriate location. It is quite well known that the transcaruncular approach is suitable for small fractures of the medial wall. Since the transcaruncular approach provides surgeons with only a narrow view, it is difficult to restore the orbital tissues for the appropriate location for a large depressed fracture. On the other hand, the Lynch incision provides a substantial advantage for the repair of an orbital fracture, as it allows for a wide view during surgery and makes it easy to restore the orbital tissues for the orbit and insert the reconstruction implant. In additi...
With great interest, we read the e letter (E-Letter 1) submitted by Ankita Anil Patil, Srikanth Ramsubramanian, and Bipasha Mukherjee, entitled “Comments on article ‘Impact of surgical timing on postoperative ocular motility in orbital blowout fractures’” illustrating their analysis and opinions on our article that was recently published in the British Journal of Ophthalmology. Please know that we greatly appreciate the authors’ cogent and helpful comments.
It should be noted that in our opinion, in order to normalize ocular motility, the most important aspect is to restore the orbital tissues for the appropriate location. It is quite well known that the transcaruncular approach is suitable for small fractures of the medial wall. Since the transcaruncular approach provides surgeons with only a narrow view, it is difficult to restore the orbital tissues for the appropriate location for a large depressed fracture. On the other hand, the Lynch incision provides a substantial advantage for the repair of an orbital fracture, as it allows for a wide view during surgery and makes it easy to restore the orbital tissues for the orbit and insert the reconstruction implant. In addition, and from our experience, the Lynch incision never results in severe scarring or webbing of the medial canthal skin. Hence, we select the Lynch incision for the repair of medial wall fractures. Moreover, we never experience any suture-related problems, as the tissue is properly squeezed at the time that suturing is performed and troubles such as ectropion never occur.
As for the correct number of patients mentioned in the Results section of our article who had poor improvement of HAR%, that number was 22.
In regard to the Forced Duction Test (FDT), it should be noted that under general anesthesia we performed the FDT before and after the surgical repair. We performed the FDT in order to confirm whether or not the orbital tissue reconstruction had been released, and then recorded the FDT score. When we diagnose muscle and tissue incarceration, the diagnosis is based on both CT-SCAN and the FDT. However, it should be noted that the FDT is the objective method.
In closing, please know once again that we greatly appreciate the authors’ comments.
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, f...
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, for example STROBE for observational studies, CONSORT for randomized trials, and PRISMA for systematic reviews and meta-analyses of intervention studies (see https://www.equator-network.org/reporting-guidelines/ for a full list of reporting standards).
Related to this project, CEV is examining the quality of published systematic review methods and maintains a database of systematic reviews in eyes and vision (http://cmr.cochrane.org/?CRGReportID=11343). We classify systematic reviews as “reliable” based on adherence to pre-specified criteria, (3) and send the “reliable” reviews to the American Academy of Ophthalmology for reference when issuing clinical practice guidelines. (4)
We urge all stakeholders to join our effort to ensure that vision science is recognized as evidence-based.
Literature cited
1. Joksimovic L, Koucheki R, Popovic M, Ahmed Y, Schlenker MB, Ahmed IIK. Risk of bias assessment of randomized controlled trials in high-impact ophthalmology journals and general medical journals: a systematic review. Br J Ophthalmol 2017;0:1–6. doi:10.1136/bjophthalmol-2017-310313
2. Institute of Medicine (IOM). Finding what works in health care: Standards for systematic reviews. Washington, DC: The National Academies Press; 2011
3. Lindsley K, Li T, Ssemanda E, Virgili G, Dickersin K. Interventions for age-related macular degeneration: Are practice guidelines based on systematic reviews? Ophthalmol. 2016;123(4):884-97. doi:10.1016/j.ophtha.2015.12.004.
4. Mayo-Wilson E, Ng SM, Chuck RS, Li T. The quality of systematic reviews about interventions for refractive error can be improved: a review of systematic reviews. BMC Ophthalmol.2017; 17:164 doi:10.1186/s12886-017-0561-9.
Aptel et al. [1] presented the prevention and management of postoperative ocular inflammation after cataract surgery based on randomised controlled trials, while after trabeculectomy, vitrectomy and combined phacovitrectomy in a two-round Delphi survey.
The Delphi survey is a technique applied mainly to develop healthcare quality indicators. [2] In this study not only was it applied to evaluate practice patterns among ophthalmologists, but to obtain information on inflammatory potential of a surgical procedure that can be assessed by objective methods.
It should be underlined that even within the formerly mentioned indications there is little recommendation among researchers to use the Delphi method. [2] The use and reporting of the method needs to be improved, while a panel composition of experts in one field significantly influences ratings. [2,3] Several issues regarding the selection of the panel members is critical if the group consensus technique is to work properly. Two hundred and twenty surgeons from Europe (35%) and the USA (59%) were invited to participate in this Delphi survey. The response rate among the invited experts should be thoroughly explained, as finally 82% of the participating experts were from Europe and the balance was from the USA. This discrepancy might have a high risk of bias and should be thoroughly discussed. Of record, in the United States retinal surgeons do not routinely perform cataract surgery, thus including them in the e...
Aptel et al. [1] presented the prevention and management of postoperative ocular inflammation after cataract surgery based on randomised controlled trials, while after trabeculectomy, vitrectomy and combined phacovitrectomy in a two-round Delphi survey.
The Delphi survey is a technique applied mainly to develop healthcare quality indicators. [2] In this study not only was it applied to evaluate practice patterns among ophthalmologists, but to obtain information on inflammatory potential of a surgical procedure that can be assessed by objective methods.
It should be underlined that even within the formerly mentioned indications there is little recommendation among researchers to use the Delphi method. [2] The use and reporting of the method needs to be improved, while a panel composition of experts in one field significantly influences ratings. [2,3] Several issues regarding the selection of the panel members is critical if the group consensus technique is to work properly. Two hundred and twenty surgeons from Europe (35%) and the USA (59%) were invited to participate in this Delphi survey. The response rate among the invited experts should be thoroughly explained, as finally 82% of the participating experts were from Europe and the balance was from the USA. This discrepancy might have a high risk of bias and should be thoroughly discussed. Of record, in the United States retinal surgeons do not routinely perform cataract surgery, thus including them in the expert panel comparing the inflammatory potential of the former is debatable.
Finally, the manuscript has several editorial errors, including references not adjusted to the journal requirements. As of high interest of the pharmaceutical industry in broadening the use of topical non-steroidal anti-inflammatory drugs, we believe financial disclosures of all authors, as well as the interest of the sponsor should be disclosed.
References
1. Aptel F, Colin C, Kaderli S, et al. Management of postoperative inflammation after cataract and complex ocular surgeries: a systematic review and Delphi survey. Br J Ophthalmol. August 2017. doi:10.1136/bjophthalmol-2017-310324.
2. Boulkedid R, Abdoul H, Loustau M, Sibony O, Alberti C. Using and reporting the Delphi method for selecting healthcare quality indicators: a systematic review. PLoS One. 2011;6(6):e20476.
3. Campbell SM, Hann M, Roland MO, Quayle JA, Shekelle PG. The Effect of Panel Membership and Feedback on Ratings in a Two-Round Delphi Survey. Med Care. 1999;37(9):964-968.
We have read the article”Impact of surgical timing of postoperative ocular motility in orbital blowout fractures” by Yukito Yamanaka, Akihide Watanabe, Chie Sotozono, Shigeru Kinoshita published in BJO on July 25 2017.The article discusses a new technique of Hess Area Ratio (HAR) and CT-scan findings for determining the appropriate time for surgery and predict the outcomes following orbital fracture repair.
We want to congratulate the authors for this successful review article. We would like to comment on some points in the methodology and results of this article and make some contributions.The incisions described in the article have some shortcomings and are not currently the favoured approach. The Lynch incision described in the article has been the traditional approach for medial wall fractures but can result in severe scarring or webbing of the medial canthal skin ; therefore the transcaruncular approach is favoured.1 The subciliary incision too can cause ectropion and a transconjunctival approach is preferred.2 The number of patients mentioned in the results section who had poor improvement of HAR% differs being recorded as 22 earlier and then later in the article as 24.The diagnosis of tissue incarceration causing ocular motility disturbances after surgery is more related to various ocular motility tests rather than CT-SCAN findings alone.3 The authors have diagnosed muscle and tissue incarceration based solely on CT-SCAN findings and have not commented on t...
We have read the article”Impact of surgical timing of postoperative ocular motility in orbital blowout fractures” by Yukito Yamanaka, Akihide Watanabe, Chie Sotozono, Shigeru Kinoshita published in BJO on July 25 2017.The article discusses a new technique of Hess Area Ratio (HAR) and CT-scan findings for determining the appropriate time for surgery and predict the outcomes following orbital fracture repair.
We want to congratulate the authors for this successful review article. We would like to comment on some points in the methodology and results of this article and make some contributions.The incisions described in the article have some shortcomings and are not currently the favoured approach. The Lynch incision described in the article has been the traditional approach for medial wall fractures but can result in severe scarring or webbing of the medial canthal skin ; therefore the transcaruncular approach is favoured.1 The subciliary incision too can cause ectropion and a transconjunctival approach is preferred.2 The number of patients mentioned in the results section who had poor improvement of HAR% differs being recorded as 22 earlier and then later in the article as 24.The diagnosis of tissue incarceration causing ocular motility disturbances after surgery is more related to various ocular motility tests rather than CT-SCAN findings alone.3 The authors have diagnosed muscle and tissue incarceration based solely on CT-SCAN findings and have not commented on the more relevant Forced Duction Test(FDT).
While the above comments don’t undermine the significance of CT-SCAN findings and HAR% in managing orbital fractures ,relevance of surgical techniques used in the study to current preferred practices , documentation of FDT and re-assessment of results for discrepancies in outcomes is imperative.
References:
(1) Jeffrey MJ and Ioannis PG . Orbital fractures: A review .Clinical ophthalmology . 2011; 5: 95–100.
(2)Raschke GF, Rieger UM, Bader RD. et al .Transconjunctival versus subciliary approach for orbital fracture repair—an anthropometric evaluation of 221 cases . Clin Oral Invest 2013; 17: 933.
(3) Lee SH, Lew H, and Young SY. Ocular Motility Disturbances in Orbital Wall Fracture Patients. Yonsei Med J. 2005 ; 46: 359–367.
Kenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the li...
Kenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the literature with regard to how visual acuity relates to increased risk of MVC’s in glaucoma patients,3-5 we suggest that these findings be more clearly emphasized. Furthermore, we would appreciate any commentary from the authors regarding visual acuity as a significant risk parameter for MVCs. Specifically, we are interested to know if further analysis of the data would show a particular threshold for visual acuity to incite a significantly higher risk for simulated collision. Given our role to responsibly report the visual capacity of patients to safely operate a motor vehicle, this information may serve useful to further guide visual acuity parameters for motor vehicle licensing.
Author Affiliations:
1. Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX
2. Michael E. Debakey Veterans Affairs Medical Center, Houston, TX
References:
1. Ramulu PY, West SK, Munoz B, Jampel HD, Friedman DS. Driving cessation and driving limitation in glaucoma: the Salisbury Eye Evaluation Project. Ophthalmology. 2009;116(10):1846-1853.
2. Janz NK, Musch DC, Gillespie BW, Wren PA, Niziol LM, Collaborative Initial Glaucoma Treatment Study I. Evaluating clinical change and visual function concerns in drivers and nondrivers with glaucoma. Invest Ophthalmol Vis Sci. 2009;50(4):1718-1725.
3. Yuki K, Awano-Tanabe S, Ono T, et al. Risk Factors for Motor Vehicle Collisions in Patients with Primary Open-Angle Glaucoma: A Multicenter Prospective Cohort Study. PLoS One. 2016;11(11):e0166943.
4. Gracitelli CP, Tatham AJ, Boer ER, et al. Predicting Risk of Motor Vehicle Collisions in Patients with Glaucoma: A Longitudinal Study. PLoS One. 2015;10(10):e0138288.
5. Kwon M, Huisingh C, Rhodes LA, McGwin G, Jr., Wood JM, Owsley C. Association between Glaucoma and At-fault Motor Vehicle Collision Involvement among Older Drivers: A Population-based Study. Ophthalmology. 2016;123(1):109-116.
Dear Editor,
we read with great interest the article by Dahlmann-Noor et al. concerning the possibility to detect optic nerve (ON) head swelling on ultrasound and OCT. 1
They reported 61 children , investigated for ‘suspicious discs’ that underwent both US and OCT. Among these only 3 children had intracranial hypertension (IHT) but all of them were diagnosed as having drusen on US; even the three children with IHT had ‘small linear’ drusen.
We would like to comment on small linear drusen that seem to have been undetected by OCT. This is very unlikely. Much care must be taken to diagnose linear drusen with ultrasound because this image could be an artifact due to the strong echoes coming from a surface where the sound beam is perpendicular .
Measuring optic nerve sheath diameter (ONSD) with B-scan has recently become popular, but there is not a global agreement on how to perform such a measurement as some authors suggest performing axial measurements, some others coronal axis measurements.3-5 Furthermore to establish a cutoff between normal and increased ONSD can be very challenging due to the so-called blooming effect. This B-scan related effect, that should not be confused with the Doppler related one, is due to the lack of sensitivity standard setting: the ON image obtained with a low sensitivity setting will result in larger ON dimensions compared to the ones provided by the same image, increasing the sensitivity setting.
The authors...
Dear Editor,
we read with great interest the article by Dahlmann-Noor et al. concerning the possibility to detect optic nerve (ON) head swelling on ultrasound and OCT. 1
They reported 61 children , investigated for ‘suspicious discs’ that underwent both US and OCT. Among these only 3 children had intracranial hypertension (IHT) but all of them were diagnosed as having drusen on US; even the three children with IHT had ‘small linear’ drusen.
We would like to comment on small linear drusen that seem to have been undetected by OCT. This is very unlikely. Much care must be taken to diagnose linear drusen with ultrasound because this image could be an artifact due to the strong echoes coming from a surface where the sound beam is perpendicular .
Measuring optic nerve sheath diameter (ONSD) with B-scan has recently become popular, but there is not a global agreement on how to perform such a measurement as some authors suggest performing axial measurements, some others coronal axis measurements.3-5 Furthermore to establish a cutoff between normal and increased ONSD can be very challenging due to the so-called blooming effect. This B-scan related effect, that should not be confused with the Doppler related one, is due to the lack of sensitivity standard setting: the ON image obtained with a low sensitivity setting will result in larger ON dimensions compared to the ones provided by the same image, increasing the sensitivity setting.
The authors correctly state that B scan can only image the anterior portion of the ONSD, in fact to examine the ON from behind the globe to the orbital apex, standardized A scan is needed.2
The measurements with standardized A-scan, blooming effect free, are much more precise and a little bit more difficult to perform, but experienced echographist should not have problems.
REFERENCES
1. Dahlmann-Noor AH, Adams GW, Moritz CD, Davis A, Hancox J, Hingorani M, et. al. Detecting optic nerve head swelling on ultrasound and optical coherence tomography in children and young people: an observational study. Br J Ophthalmol. [Preprint]. 2017 [cited 2017 June 21] doi: 10.1136/bjophthalmol-2017-310196.
2. Ossoinig KC. Standardized echography of the optic nerve. In: Till P, editor. Ophthalmic Echography 13, Documenta Ophthalmologica Proceedings Series, vol 55. Dordrecht: Springer; 1990. p. 3-99.
3. Rosa N, De Bernardo M. Measurement of the optic nerve in a resource-limited setting. J of Neur in Rural Practice. 2017 Apr-Jun;8(2):310-1.
4. Iaconetta G, De Bernardo M, Rosa N. Coronal axis measurements of the Optic Nerve sheath diameter. J US in Medicine. 2017 May;36(5):1073.
5. De Bernardo M, Rosa N. Clarification on using ultrasonography to detect intracranial pressure. JAMA Ophthalmol. 2017 Sep 1;135(9):1004-5.
Chan et al report on marked elevations in serum IgG2 that are observed in patients with orbital IgG4 related disease (IgG4-RD), with or without systemic involvement.
Using ROC area under the curve comparisons, the authors show that the serum IgG2 concentration has a higher AUC (0.9) than serum IgG4 (0.8) in detecting IgG4-RD in their cohort (comprised of 33 subjects: 20 with orbital IgG4-RD with or without systemic involvement, and 13 with non-IgG4-RD orbital inflammation).
Our group has noted this paper by Chan et al with interest as we have observed the same phenomenon of marked serum IgG2 elevations in patients with IgG4-RD, who have concomitantly low serum IgG4 concentrations. Like the patients presented by Chan et al, our IgG4-RD patients uniformly had serum IgG2 concentrations that were greater than the serum IgG4 concentration, even when the serum IgG4 concentration was very high.
Our interpretation of the apparent superior clinical utility of the serum IgG2 test in this context, is that this observation is only made when using an immunonephelometric methodology subject to two different types of analytical error:
Show Morei) antigen excess, leading to falsely low serum IgG4 measurement in a patient who in fact has a marked elevation of serum IgG4 [2] and
ii) cross reactivity of the reagent used to measure IgG2 with serum IgG4, leading to falsely high serum IgG2 measurement (this may be due to a direct and specific recognition of IgG4 epitop...
Title Page
Title:
Letter to the Editor
The article in question：
Crewe JM, Threlfall T, Clark A, Sanfilippo PG, Mackey DA. Pterygia are indicators of an increased risk of developing cutaneous melanomas. Br J Ophthalmol 2017.
Authors:
Jingjing Shen
Minqian Shen
Yuanzhi Yuan
Corresponding author:
Yuanzhi Yuan
Address：#180 Fenglin Rd., Department of Ophthalmology, Zhongshan Hospital Affiliated to Fudan University, Shanghai 200032, P.R. China
Email: yuan.yuanzhi@zs.hospital.sh.cn
Phone: +86-186 1688 1220 or +86-21-64041990 ext. 2684
Dear Editor,
We read with great interest the paper by Crewe et al.1 The authors showed that patients with pterygium had higher risk of cutaneous melanomas (CM) in a large retrospective matched-cohort study in Western Australia (WA), and suggested pterygium as an indicator for CM. The finding was interesting. However, we doubt the conclusion and its clinical relevance and public health significance.
Compared to control group, patients with pterygium had a 20% or 24% increased risk of developing CM in terms of odds ratio(OR) or incidence rate ratio (IRR), respectively. The incidence rate difference（IRD）, however, was only 27.7/100 000 person-years (PY) (Table 5., by subtracting the IR of the control group from that of the pterygium group, i.e. (186.5-158.8)/100 000 PY). The rate difference corres...
Show MoreWe read with interest the insightful comments in the e-letter submitted by Dr. Gain, Dr. He, Dr. Garcin, and Dr. Thuret on our recently published article.1 As stated in their letter, they previously reported that by using a similar triple staining (i.e., Hoechst 33342, ethidium homodimere and calcein-AM) on the endothelium of whole donor corneas stored in long-term organ culture, the endothelial cell (EC) density in the whole pool of viable ECs in the cornea is routinely, and quite substantially, overestimated.2,3 We completely agree with the authors regarding the importance of assessing the whole pool of viable ECs in corneal grafts.
We first reported at the 2009 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) that triple-staining a donor graft with propidium iodide, calcein-AM, and Hoechst 33342 allowed for a distinct discrimination between living cells and dead cells. In that report, we hypothesized that the existence of dead cells on the endothelium of the donor cornea suggests an association with the rapid loss of corneal ECs, at least at the early phase, post keratoplasty. However, Gauthier and associates reported3 that there was no difference between the density of viable ECs at day 0 and at day 5 postoperative, thus suggesting that very early EC loss in the host recipient is almost negligible. However, similar to Gain and associates, we believed that it was quite important to measure viable ECD, not to calculate just ECD by...
Show MoreWe noticed the article entitled “The existence of dead cells in donor corneal endothelium preserved with storage media” by Kitazawa with interest (Br J Ophthalmol 2017. Oct 5).
Show MoreAuthors clearly demonstrated, using a triple staining with Hoechst, Propidium Iodide and Calcein-AM, that corneas stored at 4°C in Optisol-GS for 3 to 7 days, the technic most used worldwide, bear a significant number of dead endothelial cells (ECs). They underlined that these non-viable ECs are not recognized by specular cell count done by the eye bank and that this could explain the “cell loss” inevitably noticed post graft. Our team applied, for the first time in 2011 [1] and again in 2016 [2], a similar triple staining on the endothelium of whole corneas stored in long-term organ culture at 31°C, the dominant technic in Europe. We made the same findings as Kitazawa et al. and defined the notion of viable ECD (vECD) as the number of viable ECs per surface unit. Areas without ECs (especially in Descemetic folds), dead and dying EC (that will not survive the storage) clearly explain the important discrepancy between the cell count done by the eye bank (unable to spot them) and the very early postoperative ECD. Our team also demonstrated long ago that vital Trypan blue staining used by certain eye bank is unable to spot all dying cells because its time window of positivity is very narrow, corresponding only to ECs near to desquamate [3]. Viable ECD determined by triple staining therefore appea...
Dr. Jost Jonas
Editor-in-Chief
British Journal of Ophthalmology
Dear Dr. Jonas:
With great interest, we read the e letter (E-Letter 1) submitted by Ankita Anil Patil, Srikanth Ramsubramanian, and Bipasha Mukherjee, entitled “Comments on article ‘Impact of surgical timing on postoperative ocular motility in orbital blowout fractures’” illustrating their analysis and opinions on our article that was recently published in the British Journal of Ophthalmology. Please know that we greatly appreciate the authors’ cogent and helpful comments.
It should be noted that in our opinion, in order to normalize ocular motility, the most important aspect is to restore the orbital tissues for the appropriate location. It is quite well known that the transcaruncular approach is suitable for small fractures of the medial wall. Since the transcaruncular approach provides surgeons with only a narrow view, it is difficult to restore the orbital tissues for the appropriate location for a large depressed fracture. On the other hand, the Lynch incision provides a substantial advantage for the repair of an orbital fracture, as it allows for a wide view during surgery and makes it easy to restore the orbital tissues for the orbit and insert the reconstruction implant. In additi...
Show MoreDear Editors,
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, f...
Show MoreAptel et al. [1] presented the prevention and management of postoperative ocular inflammation after cataract surgery based on randomised controlled trials, while after trabeculectomy, vitrectomy and combined phacovitrectomy in a two-round Delphi survey.
The Delphi survey is a technique applied mainly to develop healthcare quality indicators. [2] In this study not only was it applied to evaluate practice patterns among ophthalmologists, but to obtain information on inflammatory potential of a surgical procedure that can be assessed by objective methods.
It should be underlined that even within the formerly mentioned indications there is little recommendation among researchers to use the Delphi method. [2] The use and reporting of the method needs to be improved, while a panel composition of experts in one field significantly influences ratings. [2,3] Several issues regarding the selection of the panel members is critical if the group consensus technique is to work properly. Two hundred and twenty surgeons from Europe (35%) and the USA (59%) were invited to participate in this Delphi survey. The response rate among the invited experts should be thoroughly explained, as finally 82% of the participating experts were from Europe and the balance was from the USA. This discrepancy might have a high risk of bias and should be thoroughly discussed. Of record, in the United States retinal surgeons do not routinely perform cataract surgery, thus including them in the e...
Show MoreWe have read the article”Impact of surgical timing of postoperative ocular motility in orbital blowout fractures” by Yukito Yamanaka, Akihide Watanabe, Chie Sotozono, Shigeru Kinoshita published in BJO on July 25 2017.The article discusses a new technique of Hess Area Ratio (HAR) and CT-scan findings for determining the appropriate time for surgery and predict the outcomes following orbital fracture repair.
Show MoreWe want to congratulate the authors for this successful review article. We would like to comment on some points in the methodology and results of this article and make some contributions.The incisions described in the article have some shortcomings and are not currently the favoured approach. The Lynch incision described in the article has been the traditional approach for medial wall fractures but can result in severe scarring or webbing of the medial canthal skin ; therefore the transcaruncular approach is favoured.1 The subciliary incision too can cause ectropion and a transconjunctival approach is preferred.2 The number of patients mentioned in the results section who had poor improvement of HAR% differs being recorded as 22 earlier and then later in the article as 24.The diagnosis of tissue incarceration causing ocular motility disturbances after surgery is more related to various ocular motility tests rather than CT-SCAN findings alone.3 The authors have diagnosed muscle and tissue incarceration based solely on CT-SCAN findings and have not commented on t...
Kenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the li...
Show MoreDear Editor,
Show Morewe read with great interest the article by Dahlmann-Noor et al. concerning the possibility to detect optic nerve (ON) head swelling on ultrasound and OCT. 1
They reported 61 children , investigated for ‘suspicious discs’ that underwent both US and OCT. Among these only 3 children had intracranial hypertension (IHT) but all of them were diagnosed as having drusen on US; even the three children with IHT had ‘small linear’ drusen.
We would like to comment on small linear drusen that seem to have been undetected by OCT. This is very unlikely. Much care must be taken to diagnose linear drusen with ultrasound because this image could be an artifact due to the strong echoes coming from a surface where the sound beam is perpendicular .
Measuring optic nerve sheath diameter (ONSD) with B-scan has recently become popular, but there is not a global agreement on how to perform such a measurement as some authors suggest performing axial measurements, some others coronal axis measurements.3-5 Furthermore to establish a cutoff between normal and increased ONSD can be very challenging due to the so-called blooming effect. This B-scan related effect, that should not be confused with the Doppler related one, is due to the lack of sensitivity standard setting: the ON image obtained with a low sensitivity setting will result in larger ON dimensions compared to the ones provided by the same image, increasing the sensitivity setting.
The authors...
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