We read the excellent paper ‘Review of extraocular muscle biopsies and utility of biopsy in extraocular muscle enlargement’ by Eade et al.1 with great interest. The authors reviewed the pathology in extraocular muscle biopsies performed over a 25-year period and reported the clinical and radiological features that might distinguish between benign and malignant diseases. As the authors note, it is imperative for the orbital surgeon to consider a muscle biopsy when the diagnosis is in doubt. With this in mind we would like to highlight two relevant cases of simulated extraocular muscle enlargement seen radiologically due to deviated ocular position rather than a pathological process related to the muscle itself. In both cases this confused the clinical picture and nearly resulted in needless surgery.
In case 1, a 42-year-old woman was referred to the oculoplastic clinic with diplopia, reduced vision in the right eye associated with retro-bulbar pain and facial paraesthesia. On examination, there was evidence of a right esotropia with a reduction of abduction (consistent with a 6th cranial nerve palsy) associated with reduced sensation involving the V1 and V2 distribution. Optic nerve function was normal. Investigations revealed an elevated serum IgG subclass 4 (1.18 g/L) and normal serum ACE. The MRI report confirmed increased girth of the right medial rectus muscle in conjunction with enlargement and pathological enhancement of right cavernous sinus extending into...
We read the excellent paper ‘Review of extraocular muscle biopsies and utility of biopsy in extraocular muscle enlargement’ by Eade et al.1 with great interest. The authors reviewed the pathology in extraocular muscle biopsies performed over a 25-year period and reported the clinical and radiological features that might distinguish between benign and malignant diseases. As the authors note, it is imperative for the orbital surgeon to consider a muscle biopsy when the diagnosis is in doubt. With this in mind we would like to highlight two relevant cases of simulated extraocular muscle enlargement seen radiologically due to deviated ocular position rather than a pathological process related to the muscle itself. In both cases this confused the clinical picture and nearly resulted in needless surgery.
In case 1, a 42-year-old woman was referred to the oculoplastic clinic with diplopia, reduced vision in the right eye associated with retro-bulbar pain and facial paraesthesia. On examination, there was evidence of a right esotropia with a reduction of abduction (consistent with a 6th cranial nerve palsy) associated with reduced sensation involving the V1 and V2 distribution. Optic nerve function was normal. Investigations revealed an elevated serum IgG subclass 4 (1.18 g/L) and normal serum ACE. The MRI report confirmed increased girth of the right medial rectus muscle in conjunction with enlargement and pathological enhancement of right cavernous sinus extending into the superior ophthalmic fissure. The patient was considered for orbital biopsy of the enlarged medial rectus muscle to ascertain the diagnosis and specifically to consider IgG4 related-disease. The MRI scan was subsequently reviewed in the regional skull-base multidisciplinary team meeting. At this stage the extraocular muscle findings were re-interpreted as being due to unopposed medial rectus contraction (i.e. the eye was in adduction at the time of the scan) secondary to a 6th cranial nerve palsy rather than pathological enlargement. This was supported by the lack of confluence between the two pathologies with sparing of the tendinous ring. The proposed orbital biopsy was therefore cancelled. Staging imaging of the chest confirmed asymmetric left hilar and borderline mediastinal lymphadenopathy which was confirmed as non-caseating granulomatous change on biopsy. A diagnosis of systemic sarcoidosis was confirmed, with cavernous sinus involvement, and the patient was successfully treated with oral prednisolone with resolution of the 6th nerve palsy.
In case 2, orbital imaging (CT) demonstrated enlargement of the inferior and horizontal recti as well as superior oblique bilaterally. There was no clear cut diagnosis of thyroid eye diease and an orbital biopsy was considered. An MRI was requested for preoperative planning which revealed the extraocular muscles to be of normal size. The biopsy was subsequently cancelled. The radiology team retrospectively noted that the patient had been in down-gaze during the CT, looking toward the radiographer’s control room, giving another false positive of extraocular muscle enlargement.
Several studies have shown that the ocular position influences the size of the extraocular muscles, specifically the thickness and volume of the muscles increases on contraction.2-4 We recommend that the interpretation of extraocular muscle size on radiological imaging should be accompanied by an assessment of the ocular position to minimise the risk of unnecessary orbital biopsy. Local discussion with radiology departments regarding the possibility of target fixation during scans may also be warranted.
1. Eade EL, Hardy TG, McKelvie PA, McNab AA. Review of extraocular muscle biopsies and utility of biopsy in extraocular muscle enlargement. Br J Ophthalmol. 2018 Jan 19. pii: bjophthalmol-2017-311147. doi: 10.1136/bjophthalmol-2017-311147.
2. Tian S, Nishida Y, Isberg B, Lennerstrand G. MRI measurements of normal extraocular muscles and other orbital structures. Graefes Arch Clin Exp Ophthalmol. 2000;238(5):393-404.
3. Clark, RA. Demer, JL. Changes in Extraocular Muscle Volume During Ocular Duction. Investigative Ophthalmology & Visual Science. 2016;57:1106-1111.
4. Loba P, Laudanska-Olszewska I, Majos A, Stefańczyk L, Broniarczyk-Loba A. Morphometric parameters of extraocular rectus muscles evaluated by dynamic-multipositional magnetic resonance. Eur J Ophthalmol 2015;25(5):373-378.
Dear Editor,
We have read with interest the paper by Klimova et al. Some statements in the paper are confusing and may even mislead the readers.
The authors claim in the survival section of the paper that: "Vitreoretinal lymphoma is a life-threatening disease, with a 5-year survival rate of 71% in our study". Vitreoretinal lymphoma (VRL) may affect vision, and in very advanced cases that we rarely see in recent years, may destroy the eye. However, VRL per se is not what that kills the patients, but the associated brain lymphoma or in some case the systemic lymphoma.
According to the results in this study (and the title of the paper), "Combined (local and systemic) treatment in patients with PVRL showed favorable results in comparison with local therapy alone (p=0.695). However, the statistical significance was not reached". It is no wonder that they claim that combined treatment is better than local treatment when they have 60% relapses. However, no other study of intra-vitreal (IVit) Methotrexate showed such a high relapse rate. In our experience, the relapse rate is extremely low with IVit methotrexate alone. Actually, in summarizing our ten years results we had no recurrence of the intraocular disease (2) and summarizing now our 20-year experience with 113 eyes, we had only two cases of recurrences (unpublished data). It is difficult to explain the poor results of the authors’ patients, using either intravitreal methotrexate al...
Dear Editor,
We have read with interest the paper by Klimova et al. Some statements in the paper are confusing and may even mislead the readers.
The authors claim in the survival section of the paper that: "Vitreoretinal lymphoma is a life-threatening disease, with a 5-year survival rate of 71% in our study". Vitreoretinal lymphoma (VRL) may affect vision, and in very advanced cases that we rarely see in recent years, may destroy the eye. However, VRL per se is not what that kills the patients, but the associated brain lymphoma or in some case the systemic lymphoma.
According to the results in this study (and the title of the paper), "Combined (local and systemic) treatment in patients with PVRL showed favorable results in comparison with local therapy alone (p=0.695). However, the statistical significance was not reached". It is no wonder that they claim that combined treatment is better than local treatment when they have 60% relapses. However, no other study of intra-vitreal (IVit) Methotrexate showed such a high relapse rate. In our experience, the relapse rate is extremely low with IVit methotrexate alone. Actually, in summarizing our ten years results we had no recurrence of the intraocular disease (2) and summarizing now our 20-year experience with 113 eyes, we had only two cases of recurrences (unpublished data). It is difficult to explain the poor results of the authors’ patients, using either intravitreal methotrexate alone or in combination with systemic high dose methotrexate.
In their discussion, the authors write that "Vitreoretinal lymphomas are considered to be systemic disease….". It should be emphasized that this disease is in most cases a unique type of lymphoma that affects immune-privileged organs: the brain, the eye, and the testis, and only in some cases (17% in our experience), the eye disease accompanies systemic lymphoma.
References
1) Klimova A, Heissigerova J, Rihova E, et al. Combined treatment of primary vitreoretinal lymphomas significantly prolongs the time to first relapse. Br J Ophthalmol 2018, doi: 10.1136/bjophthalmol-2017-311574
2) Frenkel S, Hendler K, Siegal T, et al. Intravitreal methotrexate for treating vitreoretinal lymphoma: 10 years of experience. Br J Ophthalmol 2008;92:383-8.
Sincerely Yours,
Jacob Pe'er, M.D.
Shahar Frenkel, M.D., Ph.D.
Ocular Oncology Service
Department of Ophthalmology
Hadassah – Hebrew University Medical center
Jerusalem, Israel
We were interested to see Roberts, et. al study [1] which explored whether a hub-and-spoke model using a femtosecond laser (FL) could increase the efficiency and reduce the cost of cataract surgery.
Although the model was not cost-effective when compared to conventional phacoemulsification surgery, more efficient models should continue to be assessed. The Aravind Eye Care system uses an alternative hub-and-spoke model. Instead of separate operating theatres (OTs), the physician alternates between two beds in a single OT. This model, and the safe reuse of surgical supplies, results in phacoemulsification cataract surgery with excellent outcomes at 1/20th the cost and carbon emissions [2-4].
Roberts, et. al recommend that the ideal number of OTs to maximise the utility of an FL in a hub-and-spoke model is four. However, they were not able to evaluate the effect of adding additional OTs to their model as they only had two OTs. We suggest that adopting the Aravind model to jump to the 1:4 model without further building work could significantly alter this paper’s conclusions. We would be interested to know if elements of the Aravind model, two beds one theatre, could be adopted in their setting.
On average patients receiving FLACS spent 5.85±1.99 mins in the laser suite (LS), implying a potential throughput of between 8 and 15 cases per hour. We are interested to know the authors views on the the limits of the FL and what impact the adoption of bilateral...
We were interested to see Roberts, et. al study [1] which explored whether a hub-and-spoke model using a femtosecond laser (FL) could increase the efficiency and reduce the cost of cataract surgery.
Although the model was not cost-effective when compared to conventional phacoemulsification surgery, more efficient models should continue to be assessed. The Aravind Eye Care system uses an alternative hub-and-spoke model. Instead of separate operating theatres (OTs), the physician alternates between two beds in a single OT. This model, and the safe reuse of surgical supplies, results in phacoemulsification cataract surgery with excellent outcomes at 1/20th the cost and carbon emissions [2-4].
Roberts, et. al recommend that the ideal number of OTs to maximise the utility of an FL in a hub-and-spoke model is four. However, they were not able to evaluate the effect of adding additional OTs to their model as they only had two OTs. We suggest that adopting the Aravind model to jump to the 1:4 model without further building work could significantly alter this paper’s conclusions. We would be interested to know if elements of the Aravind model, two beds one theatre, could be adopted in their setting.
On average patients receiving FLACS spent 5.85±1.99 mins in the laser suite (LS), implying a potential throughput of between 8 and 15 cases per hour. We are interested to know the authors views on the the limits of the FL and what impact the adoption of bilateral sequential cataract surgery might have on their cost estimates, [5] assumptions about throughput and the potential viability of more intensive 1:6 or 1:8 models.
Finally, maintaining training standards while improving efficiency is a challenge and we would be interested in the authors views on how training is best catered for within their different hub and spoke models.
References
1. Roberts HW, Wagh VK, Mullens IJM, Borsci S, Ni MZ, O’Brart DPS. Evaluation of a hub-and-spoke model for the delivery of femtosecond laser-assisted cataract surgery within the context of a large randomised controlled trial. Br. J. Ophthalmol. 2018 doi: 10.1136/bjophthalmol-2017-311319
2. Thiel CL, Schehlein E, Ravilla T, et al. Cataract surgery and environmental sustainability: Waste and lifecycle assessment of phacoemulsification at a private healthcare facility. J. Cataract Refract. Surg. 2017;43(11):1391-98 doi: https://doi.org/10.1016/j.jcrs.2017.08.017
3. Hong-Gam Le JRE, Rengaraj Venkatesh, Aravind Srinivasan, Ajay Kolli, Aravind Haripriya, R. D. Ravindran, Thulasiraj Ravilla, Alan L. Robin, David W. Hutton, Joshua D. Stein. A Sustainable Model For Delivering High-Quality Efficient Cataract Surgery In Southern India. Health Aff. (Millwood). 2016;35(10):1783-90
4. Venkatesh R, van Landingham SW, Khodifad AM, et al. Carbon footprint and cost–effectiveness of cataract surgery. Curr. Opin. Ophthalmol. 2016;27(1):82-88
5. Grzybowski A, Wasinska-Borowiec W, Claoué C. Pros and cons of immediately sequential bilateral cataract surgery (ISBCS). Saudi Journal of Ophthalmology 2016;30(4):244-49 doi: 10.1016/j.sjopt.2016.09.001
I was most interested to read the review by Nazarali and co-authors to mark the centenary of the description of the exfoliation syndrome, XFS(1) sometimes called the pseudo-exfoliation syndrome (2). It is always interesting to see how our understanding increases incrementally with time and reviews such as these are important in helping shape further investigations.
The linkage of environmental factors and XFS is important and as they say not well understood. Nazarali and co-authors might like to reflect on the findings in Australian Aboriginal people (3). Aboriginal people were found to have very high rates of XFS, being present in 16% of those aged 60 and above. The presence of XFS was related to total global radiation exposure and occupation. Most interestingly, XFS was not associated with high intraocular pressure or glaucoma. Surely this is an area where more research is required.
1. Nazarali S, Damji F, Damji KF. What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago? Br J Ophthalmol 2018; doi:10.1136/bjophthalmol-2017-3111321
2.Dvorak-Theobald G. Pseudo-exfoliation of the lens capsule - relation to “true” exfoliation of the lens capsule as reported in the literature and role in the production of glaucoma capsulocuticulare. Am J Ophthalmol 2018; doi.org/10.1016/j.ajo2108.02.018
3. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302-307...
I was most interested to read the review by Nazarali and co-authors to mark the centenary of the description of the exfoliation syndrome, XFS(1) sometimes called the pseudo-exfoliation syndrome (2). It is always interesting to see how our understanding increases incrementally with time and reviews such as these are important in helping shape further investigations.
The linkage of environmental factors and XFS is important and as they say not well understood. Nazarali and co-authors might like to reflect on the findings in Australian Aboriginal people (3). Aboriginal people were found to have very high rates of XFS, being present in 16% of those aged 60 and above. The presence of XFS was related to total global radiation exposure and occupation. Most interestingly, XFS was not associated with high intraocular pressure or glaucoma. Surely this is an area where more research is required.
1. Nazarali S, Damji F, Damji KF. What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago? Br J Ophthalmol 2018; doi:10.1136/bjophthalmol-2017-3111321
2.Dvorak-Theobald G. Pseudo-exfoliation of the lens capsule - relation to “true” exfoliation of the lens capsule as reported in the literature and role in the production of glaucoma capsulocuticulare. Am J Ophthalmol 2018; doi.org/10.1016/j.ajo2108.02.018
3. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302-307
We appreciate Dr. Taylor’s interest in our paper as well as drawing our attention to environmental factors that may influence XFS in Australian aboriginal people. Certainly, this is an area that deserves further investigation. Dr Taylor’s review article presents some interesting findings, particularly regarding the high incidence of XFS in Aboriginal individuals. (1)
Consistent with recent literature, Dr. Taylor identified a ‘latitude effect’. Interestingly however, XFS was more commonly observed at lower latitudes, which contrasts other findings of high altitude exposure associated with XFS in an American population. (2)
The recognition of solar radiation exposure as an environmental factor associated with XFS is plausible due to accumulating evidence that supports this relationship. (3) While providing some useful insights, this article justifies the lack of understanding and the need for further research on environmental factors.
1. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302- 307
2. Stein JD, Pasquale LR, Talwar N, Kim DS, Reed DM, Nan B, Kang JH, Wiggs JL,Richards JE. Geographic and climatic factors associated with exfoliation syndrome. Arch Ophthalmol. 2011 Aug;129(8):1053-60.
3. Jiwani AZ, Pasquale LR. Exfoliation Syndrome and Solar Exposure: New Epidemiological Insights Into the Pathophysiology of the Disease. International ophthalmology clinics. 2015;55(4):13.
We appreciate Dr. Taylor’s interest in our paper as well as drawing our attention to environmental factors that may influence XFS in Australian aboriginal people. Certainly, this is an area that deserves further investigation. Dr Taylor’s review article presents some interesting findings, particularly regarding the high incidence of XFS in Aboriginal individuals. (1)
Consistent with recent literature, Dr. Taylor identified a ‘latitude effect’. Interestingly however, XFS was more commonly observed at lower latitudes, which contrasts other findings of high altitude exposure associated with XFS in an American population. (2)
The recognition of solar radiation exposure as an environmental factor associated with XFS is plausible due to accumulating evidence that supports this relationship. (3) While providing some useful insights, this article justifies the lack of understanding and the need for further research on environmental factors.
1. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302- 307
2. Stein JD, Pasquale LR, Talwar N, Kim DS, Reed DM, Nan B, Kang JH, Wiggs JL,Richards JE. Geographic and climatic factors associated with exfoliation syndrome. Arch Ophthalmol. 2011 Aug;129(8):1053-60.
3. Jiwani AZ, Pasquale LR. Exfoliation Syndrome and Solar Exposure: New Epidemiological Insights Into the Pathophysiology of the Disease. International ophthalmology clinics. 2015;55(4):13.
Dear Editor,
We thank Dr. Balducci and her colleagues for their interest in our paper [1]. They raise several important points regarding optic nerve angiography, and we are thankful to have the opportunity to discuss these items further.
In preparation of our manuscript, we felt that diffuse changes in the peripapillary capillary network were best appreciated at lower magnification. Balancing this objective in presentation with a sufficient resolution to appreciate the focal deficits we highlighted, the image sizes published represent what we felt was the best compromise. For those who feel that higher magnification images are needed, we have included in this letter Figure 1, which includes the same 6x6 mm OCT-A images in the acute phase for all cases in our study. Quantitation of OCT-A signal can be a powerful way to objectively assess regional as well as between eye and patient differences. We have recently performed a quantitative assessment of angiographic signal in non-arteritic anterior ischemic optic neuropathy using a different device, the Optovue Avanti (Fremont, CA) [1]. However, in the current study, the small number of affected eyes did not allow for meaningful statistical analysis of quantitative data. In addition, quantitative analyses can be misleading when confounding artifacts or segmentation errors are present as discussed below.
Jia and colleagues [2] showed a strong non-linear correlation between RNFL thickness and radial peripapillary...
Dear Editor,
We thank Dr. Balducci and her colleagues for their interest in our paper [1]. They raise several important points regarding optic nerve angiography, and we are thankful to have the opportunity to discuss these items further.
In preparation of our manuscript, we felt that diffuse changes in the peripapillary capillary network were best appreciated at lower magnification. Balancing this objective in presentation with a sufficient resolution to appreciate the focal deficits we highlighted, the image sizes published represent what we felt was the best compromise. For those who feel that higher magnification images are needed, we have included in this letter Figure 1, which includes the same 6x6 mm OCT-A images in the acute phase for all cases in our study. Quantitation of OCT-A signal can be a powerful way to objectively assess regional as well as between eye and patient differences. We have recently performed a quantitative assessment of angiographic signal in non-arteritic anterior ischemic optic neuropathy using a different device, the Optovue Avanti (Fremont, CA) [1]. However, in the current study, the small number of affected eyes did not allow for meaningful statistical analysis of quantitative data. In addition, quantitative analyses can be misleading when confounding artifacts or segmentation errors are present as discussed below.
Jia and colleagues [2] showed a strong non-linear correlation between RNFL thickness and radial peripapillary capillary density in 10 healthy subjects. That healthy subjects with normal vision and no (ischemic) posterior pole disease were analyzed is an important distinction. Indeed, there is an increase in RNFL thickness associated with ischemic optic neuropathies, but caution should be used in extrapolating trends based on normative data to the pathologic states of ischemic optic nerve disorders. In addition, arteritic anterior ischemic optic neuropathy (AAION) produces edema and is commonly associated with peripapillary cotton-wool spots that produce blockage effects, as demonstrated in cases 1-3 in our series (denoted with blue arrows) [1]. These secondary effects can alter normal anatomic boundaries and thus segmentation, which can lead to erroneous results and inaccurate conclusions in a small cohort.
With respect to the correspondence of choroidal filling defects seen on FA and OCT-A, it is important to first acknowledge that spectral domain OCT is suboptimal for imaging sub-RPE (vascular) structures due to limitations in resolution at deeper penetrance lamina [3]. Of note, we are currently collecting a series of patients with ischemic optic neuropathies imaged using swept-source OCT-A with the specific focus on choroidal vascular perfusion (Tieger et al, in preparation), though there are limitations with this approach as well. We agree that wide-field imaging may been better suited for capturing choroidal perfusion defects and have incorporated this into our imaging strategy moving forward. In the current study, we performed macular scans for some patients in addition to optic disc-centered scans in a subset of patients, including the initial presentation of case 2 (Figure 2). Fluorescein angiography revealed a clear choroidal filling defect affecting the macular region temporal to the disc and extending inferiorly (red arrow). Counter-intuitively, OCT-A showed a corresponding increase in angiographic signal in the superficial lamina and choroidal lamina (Figure 2B,D). We did not feel that the correspondence between the apparent increased choriocapillary OCT-A signal and the reduced fluorescence on FA in the area inferior to the disc (red arrows) was clear enough for publication especially in the context of other imaging limitations [3].
Balducci and colleagues [4] reported a single case of acute AAION imaged with the Optovue device and described corresponding perfusion defects on FA and OCT-A that were continuous with the optic disc. However, there are several limitations with the image presented. First, the image is confounded by motion artifact. Second, the image is too highly magnified such that the region of interest is at the edge of the sampling area, where segmentation errors can occur. Given that the retinal arterioles visible on FA are not visible in the superficial lamina on OCT-A, segmentation error is likely present, similar to case 2 in our series (Figure 3). Comparison with composite images can reveal such errors. Third, no fundus photograph is presented to exclude edema, which can impart a blockage effect as also demonstrated in case 2 in our series (Figure 2; blue arrow) [1].
In conclusion, OCT-A is a new and powerful tool for imaging microvascular anatomy in normal and pathologic conditions of the posterior pole, but OCT-A image acquisition and segmentation can be prone to artifact and misrepresentation. Balducci and colleagues highlight a number of these pitfalls in the early application of this new technology in the analysis of ischemic optic neuropathies. As the field continues to explore the application of OCT-A, it will be critical to remember that the study of the pathologic state teaches us about the technology (and limitations therein) just as the technology provides new insights into the pathophysiology.
Figures can be downloaded at the following link and will be available through 8/31/2019: https://www.dropbox.com/sh/kf1fp9gsuas4zm1/AACLiIA2cKLF_J9nkWGdymPza?dl=0
Conflicts of Interest: None
FIGURE LEGENDS
Figure 1. Enlarged Optical Coherence Tomographic Angiography (OCT-A) images (6 mmx 6 mm; Zeiss) of all controls and cases. Superficial, choriocapillary and choroidal laminar segmentations are included. The right (top) and left (bottom) eyes are included for each case, which are demarcated by red lines.
Figure 2. Enlarged and expanded OCT-A sampling regions for case 2. (A) Corresponding fluorescein angiography image (early) depicting blockage by an overlying cotton wool spot along the superior arcade (blue arrow) and choroidal hypoperfusion temporal to the optic disc most prominent inferiorly (red arrow) (represented as Figure 3H in initial report). (B-D) Superficial, choriocappilary and choroidal laminar segmented OCT-A images are included with montaged samplings centered on the optic disc and macula. Blue and red arrow represent the same regions corresponding to those in the fluorescein angiogram; the blue arrows indicate signal blockage extending through all lamina, and the red arrows indicate the region with increased OCT-A signal in the superficial and choroidal laminae. The yellow arrow denotes attenuated OCT-A signal in a region superior to the optic disc in the superficial lamina. Images are each 6 mm x 6 mm and were acquired using the Zeiss device.
Figure 3. Enlarged OCT-A images for re-presentation of case with optic disc edema and AAION. (A) Fundus photograph of the optic disc depicting pallid optic disc edema that is obscuring the peripapillary retinal arterials (blue arrow). (B,C) Composite and superficial laminar OCT-A images (3 mm x 3 mm; Optovue) for the corresponding region depicted in the fundus photograph. There is apparent retinal arterial signal attenuation in the superficial lamina (C) as denoted by the blue arrow that is partially secondary to segmentation error as it is better preserved in the composite segmentation (B; blue arrow). There is some component of blockage due to overlying edema as evident in the fundus photograph, but some regions of peripapillary OCT-A signal attenuation likely represent true hypoperfusion as they do not correspond to overlying blockage elements (for example: yellow arrow).
REFERENCES
1. Gaier ED, Gilbert AL, Cestari DM, Miller JB. Optical coherence tomographic angiography identifies peripapillary microvascular dilation and focal non-perfusion in giant cell arteritis. Br J Ophthalmol 2018;102(8):1141-46.
2. Jia Y, Simonett JM, Wang J, et al. Wide-Field OCT Angiography Investigation of the Relationship Between Radial Peripapillary Capillary Plexus Density and Nerve Fiber Layer Thickness. Invest Ophthalmol Vis Sci 2017;58(12):5188-94.
3. Diaz JD, Wang JC, Oellers P, et al. Imaging the Deep Choroidal Vasculature Using Spectral Domain and Swept Source Optical Coherence Tomography Angiography. Journal of vitreoretinal diseases 2018;2(3):146-54.
4. Balducci N, Morara M, Veronese C, et al. Optical coherence tomography angiography in acute arteritic and non-arteritic anterior ischemic optic neuropathy. Graefes Arch Clin Exp Ophthalmol 2017;255(11):2255-61.
Dear Editor,
We read with interest the paper by Gaier et al.1 The collection of 5 eyes affected by acute A-AION and analyzed with OCT-A is remarkable, due to the rare disease presentation. The main finding of the paper was that during the acute phase of A-AION, diffusely dilated superficial peripapillary capillaries were detectable on OCT-A. Interestingly, peripapillary capillary dilatation was also noted in the fellow eye. Unfortunately, the figures presented by the authors are too small to allow the reader to qualitatively appreciate the capillaries dilatation. More detailed images and a quantitative vessels analysis would have helped to document the microvascular changes.
They hypothesized that the capillary dilatation may represent a form of luxury perfusion in the setting of short ciliary arterial compromise or a centrally mediated autoregolatory mechanisms in the setting of reduced perfusion of the optic nerve. These hypotheses are interesting, but it is important to differentiate the RNFL thickness increase from the capillary dilatation, as peripapillary capillary plexus density and RNFL thickness are highly correlated and fit well with a nonlinear stacked-layer model.2
Moreover, the authors stated that OCT-A laminar analysis did not highlight the choroidal/choriocapillaris perfusion defects seen on FA. However, a recent study3 showed a tight correspondence between the choroidal perfusion defects visible on FA (and even better on indocyanine green...
Dear Editor,
We read with interest the paper by Gaier et al.1 The collection of 5 eyes affected by acute A-AION and analyzed with OCT-A is remarkable, due to the rare disease presentation. The main finding of the paper was that during the acute phase of A-AION, diffusely dilated superficial peripapillary capillaries were detectable on OCT-A. Interestingly, peripapillary capillary dilatation was also noted in the fellow eye. Unfortunately, the figures presented by the authors are too small to allow the reader to qualitatively appreciate the capillaries dilatation. More detailed images and a quantitative vessels analysis would have helped to document the microvascular changes.
They hypothesized that the capillary dilatation may represent a form of luxury perfusion in the setting of short ciliary arterial compromise or a centrally mediated autoregolatory mechanisms in the setting of reduced perfusion of the optic nerve. These hypotheses are interesting, but it is important to differentiate the RNFL thickness increase from the capillary dilatation, as peripapillary capillary plexus density and RNFL thickness are highly correlated and fit well with a nonlinear stacked-layer model.2
Moreover, the authors stated that OCT-A laminar analysis did not highlight the choroidal/choriocapillaris perfusion defects seen on FA. However, a recent study3 showed a tight correspondence between the choroidal perfusion defects visible on FA (and even better on indocyanine green angiography) and on OCT-A at the level of the choriocapillary in a single case of acute A-AION.
The choroidal defects noted on FA by Gaier et al.1 were slightly distant from optic disc border and they did not fit inside the small scan area of the OCT-A exam. Larger OCT-A scan size could help to highlight choriocapillaris perfusion defect in those cases.
References
1 Gaier ED, Gilbert AL, Cestari DM, Miller JB. Optical coherence tomography angiography identifies peripapillary microvascular dilation and focal non-perfusion in giant cell arteritis. Br J Ophthalmol Published Online First: [2017 Nov 9] DOI: 10.1136/bjophthalmol-2017-310718
2 Jia Y, Simonett JM, Wang J1, et al. Wide-Field OCT Angiography Investigation of the Relationship Between Radial Peripapillary Capillary Plexus Density and Nerve Fiber Layer Thickness. Invest Ophthalmol Vis Sci. 2017;58:5188-5194.
3Balducci N, Morara M, Veronese C, et al. Optical coherence tomography angiography in acute arteritic and non-arteritic anterior ischemic optic neuropathy. Graefes Arch Clin Exp Ophthalmol 2017;255:2255-2261.
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 thank the authors for their comments and insights on our paper ‘Pterygia are indicators of an increased risk of developing cutaneous melanomas’.
We agree that there was selection bias within the pterygium cases. All cases were identified as hospital in-patients and therefore represent that small select portion of the population who were receiving treatment for (or removal of) their pterygium. We made no assumptions about whether these cases were more or less severe than untreated pterygia or whether the removals were performed for cosmetic or other reasons. The strengths of this study are that it included all in-hospital cases treated in Western Australia over a 30 year time period, without prejudice.
While melanoma is an uncommon problem in China, it is a major health issue in Australia and New Zealand. The clinical relevance of this study should be viewed against the background of the world’s highest incidence rates of cutaneous melanoma that currently exist, with up to 60 cases per 100,000 population1-3 in Australia and New Zealand. Contrast this with the incidence rates of East Asian countries of approximately 0.7 cases per 100,000 population.4 Both non-melanoma and melanoma skin cancers are a major health priority for cancer prevention research. We are not suggesting that pterygium be used as the sole indicator for a population wide screening program. There are well established major screening and surveillance programs in place in Australia. Our study a...
We thank the authors for their comments and insights on our paper ‘Pterygia are indicators of an increased risk of developing cutaneous melanomas’.
We agree that there was selection bias within the pterygium cases. All cases were identified as hospital in-patients and therefore represent that small select portion of the population who were receiving treatment for (or removal of) their pterygium. We made no assumptions about whether these cases were more or less severe than untreated pterygia or whether the removals were performed for cosmetic or other reasons. The strengths of this study are that it included all in-hospital cases treated in Western Australia over a 30 year time period, without prejudice.
While melanoma is an uncommon problem in China, it is a major health issue in Australia and New Zealand. The clinical relevance of this study should be viewed against the background of the world’s highest incidence rates of cutaneous melanoma that currently exist, with up to 60 cases per 100,000 population1-3 in Australia and New Zealand. Contrast this with the incidence rates of East Asian countries of approximately 0.7 cases per 100,000 population.4 Both non-melanoma and melanoma skin cancers are a major health priority for cancer prevention research. We are not suggesting that pterygium be used as the sole indicator for a population wide screening program. There are well established major screening and surveillance programs in place in Australia. Our study adds a new variable to the calculation of risk for individuals (along with skin colour, hair colour, latitude and sun exposure). We do not believe our findings will cause increased anxiety to people who develop pterygium but will be a useful aid to increasing awareness of the health risks associated with high levels of solar radiation that are a part of life in Australia.
Table 5 age groups are correct as shown but could also be written as: <50 (aged 0 to 49.99) years and ≥50 (aged 50 or more) years.
The suggested correction (>50 years and <49 years) would exclude all people aged 50 years which would be incorrect for the data shown.
Julie Crewe
Tim Threlfall
Antony Clark
Paul Sanfilippo
Professor David Mackey
References
1 MacLennan R, Green AC, McLeod GRC, Martin NG. Increasing Incidence of Cutaneous Melanoma in Queensland, Australia. JNCI: Journal of the National Cancer Institute. 1992;84(18):1427-32 DOI:10.1093/jnci/84.18.1427
2 Marks R. The Changing Incidence and Mortality of Melanoma in Australia. In: Dummer R, Nestle FO, Burg G, editors. Cancers of the Skin: Proceedings of the 8th World Congress. Berlin, Heidelberg: Springer Berlin Heidelberg; 2002. p. 113-21.
3 Garbe C, Leiter U. Melanoma epidemiology and trends. Clinics in Dermatology. 2009;27(1):3-9 https://doi.org/10.1016/j.clindermatol.2008.09.001
4 Makredes M, Hui SK, Kimball AB. Melanoma in Hong Kong between 1983 and 2002: a decreasing trend in incidence observed in a complex socio–political and economic setting. Melanoma Research. 2010;20(5):427-30 DOI:10.1097/CMR.0b013e3283281072
Dear Editor,
We have read with interest the recently published article by Al Arrayedh H, Collum L, Murphy CC (1). The authors concluded that a poor outcome was seen after PKP for CHED in Irish population, which arises from a combination of dense amblyopia and a high risk of graft failure in the long term. This is an important study which has a unique cohort of only autosomal recessive cases from a large Irish consanguineous family.
We want to highlight some points in this article that were not clearly described .
Author reported 2 previously diagnosed congenital glaucoma cases, which also affects the visual outcome of the surgery and may skew results of this study. But they had not mentioned clearly about this.
In the figure 2 , the failed DSEK case also received regrafting twice but that was not shown in the legend.Also 32 eyes received penetrating keratoplasty as per the text but in that figure , 33 was mentioned.
In some previous studies 12 years of age (2,3) has been mentioned as the demarcation for outcome of penetrating keratoplasty in congenital hereditary endothelial dystrophy . This was not analysed in this very important study (maybe because of small numbers) but it could have been a useful clinical hint for timing of surgery in these patients.
Thanks
1. AlArrayedh H, Collum L, Murphy CC. Outcomes of penetrating keratoplasty in congenital hereditary endothelial dystrophy. Br J Ophthalmol. 2018 Jan;102(1):19-25 ...
Dear Editor,
We have read with interest the recently published article by Al Arrayedh H, Collum L, Murphy CC (1). The authors concluded that a poor outcome was seen after PKP for CHED in Irish population, which arises from a combination of dense amblyopia and a high risk of graft failure in the long term. This is an important study which has a unique cohort of only autosomal recessive cases from a large Irish consanguineous family.
We want to highlight some points in this article that were not clearly described .
Author reported 2 previously diagnosed congenital glaucoma cases, which also affects the visual outcome of the surgery and may skew results of this study. But they had not mentioned clearly about this.
In the figure 2 , the failed DSEK case also received regrafting twice but that was not shown in the legend.Also 32 eyes received penetrating keratoplasty as per the text but in that figure , 33 was mentioned.
In some previous studies 12 years of age (2,3) has been mentioned as the demarcation for outcome of penetrating keratoplasty in congenital hereditary endothelial dystrophy . This was not analysed in this very important study (maybe because of small numbers) but it could have been a useful clinical hint for timing of surgery in these patients.
Thanks
1. AlArrayedh H, Collum L, Murphy CC. Outcomes of penetrating keratoplasty in congenital hereditary endothelial dystrophy. Br J Ophthalmol. 2018 Jan;102(1):19-25
2. Özdemir B, Kubaloğlu A, Koytak A, Coskun E, Çinar Y, Sari ES, Özertürk Y. Penetrating keratoplasty in congenital hereditary endothelial dystrophy. Cornea. 2012 Apr;31(4):359-65
3. Schaumberg DA, Moyes AL, Gomes JA, Dana MR. Corneal transplantation in young children with congenital hereditary endothelial dystrophy. Multicenter Pediatric Keratoplasty Study. Am J Ophthalmol. 1999 Apr;127(4):373-8
We read the excellent paper ‘Review of extraocular muscle biopsies and utility of biopsy in extraocular muscle enlargement’ by Eade et al.1 with great interest. The authors reviewed the pathology in extraocular muscle biopsies performed over a 25-year period and reported the clinical and radiological features that might distinguish between benign and malignant diseases. As the authors note, it is imperative for the orbital surgeon to consider a muscle biopsy when the diagnosis is in doubt. With this in mind we would like to highlight two relevant cases of simulated extraocular muscle enlargement seen radiologically due to deviated ocular position rather than a pathological process related to the muscle itself. In both cases this confused the clinical picture and nearly resulted in needless surgery.
In case 1, a 42-year-old woman was referred to the oculoplastic clinic with diplopia, reduced vision in the right eye associated with retro-bulbar pain and facial paraesthesia. On examination, there was evidence of a right esotropia with a reduction of abduction (consistent with a 6th cranial nerve palsy) associated with reduced sensation involving the V1 and V2 distribution. Optic nerve function was normal. Investigations revealed an elevated serum IgG subclass 4 (1.18 g/L) and normal serum ACE. The MRI report confirmed increased girth of the right medial rectus muscle in conjunction with enlargement and pathological enhancement of right cavernous sinus extending into...
Show MoreDear Editor,
We have read with interest the paper by Klimova et al. Some statements in the paper are confusing and may even mislead the readers.
The authors claim in the survival section of the paper that: "Vitreoretinal lymphoma is a life-threatening disease, with a 5-year survival rate of 71% in our study". Vitreoretinal lymphoma (VRL) may affect vision, and in very advanced cases that we rarely see in recent years, may destroy the eye. However, VRL per se is not what that kills the patients, but the associated brain lymphoma or in some case the systemic lymphoma.
According to the results in this study (and the title of the paper), "Combined (local and systemic) treatment in patients with PVRL showed favorable results in comparison with local therapy alone (p=0.695). However, the statistical significance was not reached". It is no wonder that they claim that combined treatment is better than local treatment when they have 60% relapses. However, no other study of intra-vitreal (IVit) Methotrexate showed such a high relapse rate. In our experience, the relapse rate is extremely low with IVit methotrexate alone. Actually, in summarizing our ten years results we had no recurrence of the intraocular disease (2) and summarizing now our 20-year experience with 113 eyes, we had only two cases of recurrences (unpublished data). It is difficult to explain the poor results of the authors’ patients, using either intravitreal methotrexate al...
Show MoreWe were interested to see Roberts, et. al study [1] which explored whether a hub-and-spoke model using a femtosecond laser (FL) could increase the efficiency and reduce the cost of cataract surgery.
Although the model was not cost-effective when compared to conventional phacoemulsification surgery, more efficient models should continue to be assessed. The Aravind Eye Care system uses an alternative hub-and-spoke model. Instead of separate operating theatres (OTs), the physician alternates between two beds in a single OT. This model, and the safe reuse of surgical supplies, results in phacoemulsification cataract surgery with excellent outcomes at 1/20th the cost and carbon emissions [2-4].
Roberts, et. al recommend that the ideal number of OTs to maximise the utility of an FL in a hub-and-spoke model is four. However, they were not able to evaluate the effect of adding additional OTs to their model as they only had two OTs. We suggest that adopting the Aravind model to jump to the 1:4 model without further building work could significantly alter this paper’s conclusions. We would be interested to know if elements of the Aravind model, two beds one theatre, could be adopted in their setting.
On average patients receiving FLACS spent 5.85±1.99 mins in the laser suite (LS), implying a potential throughput of between 8 and 15 cases per hour. We are interested to know the authors views on the the limits of the FL and what impact the adoption of bilateral...
Show MoreDear Sir,
I was most interested to read the review by Nazarali and co-authors to mark the centenary of the description of the exfoliation syndrome, XFS(1) sometimes called the pseudo-exfoliation syndrome (2). It is always interesting to see how our understanding increases incrementally with time and reviews such as these are important in helping shape further investigations.
The linkage of environmental factors and XFS is important and as they say not well understood. Nazarali and co-authors might like to reflect on the findings in Australian Aboriginal people (3). Aboriginal people were found to have very high rates of XFS, being present in 16% of those aged 60 and above. The presence of XFS was related to total global radiation exposure and occupation. Most interestingly, XFS was not associated with high intraocular pressure or glaucoma. Surely this is an area where more research is required.
1. Nazarali S, Damji F, Damji KF. What have we learned about exfoliation syndrome since its discovery by John Lindberg 100 years ago? Br J Ophthalmol 2018; doi:10.1136/bjophthalmol-2017-3111321
Show More2.Dvorak-Theobald G. Pseudo-exfoliation of the lens capsule - relation to “true” exfoliation of the lens capsule as reported in the literature and role in the production of glaucoma capsulocuticulare. Am J Ophthalmol 2018; doi.org/10.1016/j.ajo2108.02.018
3. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302-307...
Dear Sir,
We appreciate Dr. Taylor’s interest in our paper as well as drawing our attention to environmental factors that may influence XFS in Australian aboriginal people. Certainly, this is an area that deserves further investigation. Dr Taylor’s review article presents some interesting findings, particularly regarding the high incidence of XFS in Aboriginal individuals. (1)
Consistent with recent literature, Dr. Taylor identified a ‘latitude effect’. Interestingly however, XFS was more commonly observed at lower latitudes, which contrasts other findings of high altitude exposure associated with XFS in an American population. (2)
The recognition of solar radiation exposure as an environmental factor associated with XFS is plausible due to accumulating evidence that supports this relationship. (3) While providing some useful insights, this article justifies the lack of understanding and the need for further research on environmental factors.
1. Taylor HR. Pseudoexfoliation, an environmental disease? Trans Ophthalmol Socs UK 1979; 99: 302- 307
...Show More2. Stein JD, Pasquale LR, Talwar N, Kim DS, Reed DM, Nan B, Kang JH, Wiggs JL,Richards JE. Geographic and climatic factors associated with exfoliation syndrome. Arch Ophthalmol. 2011 Aug;129(8):1053-60.
3. Jiwani AZ, Pasquale LR. Exfoliation Syndrome and Solar Exposure: New Epidemiological Insights Into the Pathophysiology of the Disease. International ophthalmology clinics. 2015;55(4):13.
Dear Editor,
Show MoreWe thank Dr. Balducci and her colleagues for their interest in our paper [1]. They raise several important points regarding optic nerve angiography, and we are thankful to have the opportunity to discuss these items further.
In preparation of our manuscript, we felt that diffuse changes in the peripapillary capillary network were best appreciated at lower magnification. Balancing this objective in presentation with a sufficient resolution to appreciate the focal deficits we highlighted, the image sizes published represent what we felt was the best compromise. For those who feel that higher magnification images are needed, we have included in this letter Figure 1, which includes the same 6x6 mm OCT-A images in the acute phase for all cases in our study. Quantitation of OCT-A signal can be a powerful way to objectively assess regional as well as between eye and patient differences. We have recently performed a quantitative assessment of angiographic signal in non-arteritic anterior ischemic optic neuropathy using a different device, the Optovue Avanti (Fremont, CA) [1]. However, in the current study, the small number of affected eyes did not allow for meaningful statistical analysis of quantitative data. In addition, quantitative analyses can be misleading when confounding artifacts or segmentation errors are present as discussed below.
Jia and colleagues [2] showed a strong non-linear correlation between RNFL thickness and radial peripapillary...
Dear Editor,
Show MoreWe read with interest the paper by Gaier et al.1 The collection of 5 eyes affected by acute A-AION and analyzed with OCT-A is remarkable, due to the rare disease presentation. The main finding of the paper was that during the acute phase of A-AION, diffusely dilated superficial peripapillary capillaries were detectable on OCT-A. Interestingly, peripapillary capillary dilatation was also noted in the fellow eye. Unfortunately, the figures presented by the authors are too small to allow the reader to qualitatively appreciate the capillaries dilatation. More detailed images and a quantitative vessels analysis would have helped to document the microvascular changes.
They hypothesized that the capillary dilatation may represent a form of luxury perfusion in the setting of short ciliary arterial compromise or a centrally mediated autoregolatory mechanisms in the setting of reduced perfusion of the optic nerve. These hypotheses are interesting, but it is important to differentiate the RNFL thickness increase from the capillary dilatation, as peripapillary capillary plexus density and RNFL thickness are highly correlated and fit well with a nonlinear stacked-layer model.2
Moreover, the authors stated that OCT-A laminar analysis did not highlight the choroidal/choriocapillaris perfusion defects seen on FA. However, a recent study3 showed a tight correspondence between the choroidal perfusion defects visible on FA (and even better on indocyanine green...
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 thank the authors for their comments and insights on our paper ‘Pterygia are indicators of an increased risk of developing cutaneous melanomas’.
Show MoreWe agree that there was selection bias within the pterygium cases. All cases were identified as hospital in-patients and therefore represent that small select portion of the population who were receiving treatment for (or removal of) their pterygium. We made no assumptions about whether these cases were more or less severe than untreated pterygia or whether the removals were performed for cosmetic or other reasons. The strengths of this study are that it included all in-hospital cases treated in Western Australia over a 30 year time period, without prejudice.
While melanoma is an uncommon problem in China, it is a major health issue in Australia and New Zealand. The clinical relevance of this study should be viewed against the background of the world’s highest incidence rates of cutaneous melanoma that currently exist, with up to 60 cases per 100,000 population1-3 in Australia and New Zealand. Contrast this with the incidence rates of East Asian countries of approximately 0.7 cases per 100,000 population.4 Both non-melanoma and melanoma skin cancers are a major health priority for cancer prevention research. We are not suggesting that pterygium be used as the sole indicator for a population wide screening program. There are well established major screening and surveillance programs in place in Australia. Our study a...
Dear Editor,
We have read with interest the recently published article by Al Arrayedh H, Collum L, Murphy CC (1). The authors concluded that a poor outcome was seen after PKP for CHED in Irish population, which arises from a combination of dense amblyopia and a high risk of graft failure in the long term. This is an important study which has a unique cohort of only autosomal recessive cases from a large Irish consanguineous family.
We want to highlight some points in this article that were not clearly described .
Author reported 2 previously diagnosed congenital glaucoma cases, which also affects the visual outcome of the surgery and may skew results of this study. But they had not mentioned clearly about this.
In the figure 2 , the failed DSEK case also received regrafting twice but that was not shown in the legend.Also 32 eyes received penetrating keratoplasty as per the text but in that figure , 33 was mentioned.
In some previous studies 12 years of age (2,3) has been mentioned as the demarcation for outcome of penetrating keratoplasty in congenital hereditary endothelial dystrophy . This was not analysed in this very important study (maybe because of small numbers) but it could have been a useful clinical hint for timing of surgery in these patients.
Thanks
1. AlArrayedh H, Collum L, Murphy CC. Outcomes of penetrating keratoplasty in congenital hereditary endothelial dystrophy. Br J Ophthalmol. 2018 Jan;102(1):19-25
Show More...
Pages