We read with interest the article by Sarker et al(1) in which they compared the outcomes of trabeculectomy versus Ahmed glaucoma valve (AGV) implantation in Sturge–Weber syndrome (SWS) patients with secondary glaucoma aged 11-62 years. As it noted in the paper, the authors found that complete success rates after 24 months were 80% and 70% in the AGV and trabeculectomy groups, respectively, and qualified success rates were 90% and 85% at same period in the AGV and trabeculectomy groups, respectively. We were delighted to get the conclusion that both AGV implant and trabeculectomy appeared to be safe and efficacious in controlling glaucoma secondary to SWS.
As it reported by Mohamed et al., the complete success rate and qualified success rate (intraocular pressure≤17mmHg) of trabeculectomy reported were 80% and 100% at 12 postoperative follow-up month, respectively(2). However, the qualified success rate (90%) of AGV implantation in SWS patients with secondary glaucoma is higher than that reported by Hamush et al. (79%)(3) and Kaushik et al. (76%)(4) at 2 years of follow-up. Meanwhile, the trabeculectomy with MMC success rate in this study was comparable to other studies about primary glaucoma(5, 6), but the success rate of tube shunt surgery was higher than in prior reports. The qualified success rate of Baerveldt implantation for patients who not had undergone previous incisional ocular surgery was 73% in Primary Tube Versus Trabeculectomy (PTVT) study(6) and 75% rep...
We read with interest the article by Sarker et al(1) in which they compared the outcomes of trabeculectomy versus Ahmed glaucoma valve (AGV) implantation in Sturge–Weber syndrome (SWS) patients with secondary glaucoma aged 11-62 years. As it noted in the paper, the authors found that complete success rates after 24 months were 80% and 70% in the AGV and trabeculectomy groups, respectively, and qualified success rates were 90% and 85% at same period in the AGV and trabeculectomy groups, respectively. We were delighted to get the conclusion that both AGV implant and trabeculectomy appeared to be safe and efficacious in controlling glaucoma secondary to SWS.
As it reported by Mohamed et al., the complete success rate and qualified success rate (intraocular pressure≤17mmHg) of trabeculectomy reported were 80% and 100% at 12 postoperative follow-up month, respectively(2). However, the qualified success rate (90%) of AGV implantation in SWS patients with secondary glaucoma is higher than that reported by Hamush et al. (79%)(3) and Kaushik et al. (76%)(4) at 2 years of follow-up. Meanwhile, the trabeculectomy with MMC success rate in this study was comparable to other studies about primary glaucoma(5, 6), but the success rate of tube shunt surgery was higher than in prior reports. The qualified success rate of Baerveldt implantation for patients who not had undergone previous incisional ocular surgery was 73% in Primary Tube Versus Trabeculectomy (PTVT) study(6) and 75% reported by Islamaj et al(5)at 2 years of follow-up. The qualified success rates of AGV implantation and Baerveldt implantation for patients with refractory glaucoma were 76% and 68% at 2 years of follow-up, respectively(7).
This more favorable result of AGV implantation relative to previous reports may because this small sample size study excluded 8 patients (16.7%), enrolled patients may uncomplete 2 years of review, or most of them are older than 18 years old compared with other study about SWS patients with secondary glaucoma(3, 4). The study enrolled eyes may at lower risk of surgical failure than that excluded from the study. As the authors mentioned, a total of 48 patients in glaucoma associated with SWS were surgically treated and 8 patients were excluded because of unreliable follow-ups and/or incomplete case records. Substantial differences in the success rate of cases with and without follow-up may overestimate the success rates of two surgeries and prove misleading on interpreting the results in this small sample size, retrospective study. What’s more, mean±SD follow-up in the study was 23.15±2.36 (range, 15–24) and 22.95±2.87 (range, 13–24) in the AGV and trabeculectomy groups, respectively, which may indicate incomplete 2 years of review for some patients. Patients who experienced successful surgical treatment at 15 months may subsequently experience treatment failure at 24 months. It’s better to supplement the number of patients at each follow up visit.
In conclusion, since the small sample size, it is better to supplement the outcomes of eight patients excluded from the study and the number of patients at each follow up visit so as to yield more convincing results.
Reference
1. Sarker BK, Malek MA, Mannaf SMA, Iftekhar QS, Mahatma M, Sarkar MK, et al. Outcome of trabeculectomy versus Ahmed glaucoma valve implantation in the surgical management of glaucoma in patients with Sturge-Weber syndrome. Br J Ophthalmol. 2021;105(11):1561-5.
2. Mohamed T, Salman A, Elshinawy R. Trabeculectomy with Ologen implant versus mitomycin C in congenital glaucoma secondary to Sturge Weber Syndrome. International journal of ophthalmology. 2018;11(2):251-5.
3. Hamush N, Coleman A, Wilson M. Ahmed glaucoma valve implant for management of glaucoma in Sturge-Weber syndrome. American journal of ophthalmology. 1999;128(6):758-60.
4. Kaushik J, Parihar J, Jain V, Mathur V. Ahmed valve implantation in childhood glaucoma associated with Sturge-Weber syndrome: our experience. Eye (London, England). 2019;33(3):464-8.
5. Islamaj E, Wubbels R, de Waard P. Primary baerveldt versus trabeculectomy study after 5 years of follow-up. Acta ophthalmologica. 2020;98(4):400-7.
6. Gedde SJ, Feuer WJ, Lim KS, Barton K, Goyal S, Ahmed IIK, et al. Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 3 Years of Follow-up. Ophthalmology. 2020;127(3):333-45.
7. Christakis P, Zhang D, Budenz D, Barton K, Tsai J, Ahmed I. Five-Year Pooled Data Analysis of the Ahmed Baerveldt Comparison Study and the Ahmed Versus Baerveldt Study. American journal of ophthalmology. 2017;176:118-26.
We read with interest the recent publication by Bertolin et al. (“In vitro establishment, validation and characterisation of conjunctival epithelium outgrowth using tissue fragments and amniotic membrane”). Their validated conjunctival analogue of the simple limbal epithelial transplantation does represent a promising advance in the field. It is, however, interesting to note that the established tissue application was mainly validated on its growth potential and not specifically on its ability to reinstate a healthy ocular mucosal surface.
Functional validation is of utmost importance, especially as the glued fragments are directly transplanted. This approach circumvents the need for expensive cell culture but also bypasses the stringent release criteria for cell therapies or tissue-engineered transplantation products. We would suggest that before this technique can be considered fully validated, it should be demonstrated that the obtained conjunctival cells contribute to the first line of mucosal defence, i.e. barrier formation. Several conjunctival barriers can be identified, such as intercellular junction complexes, glycocalyx and secreted mucins. Bertolin et al. demonstrated the presence of tight junctions (cfr. ZO-1 protein) and a glycocalyx (cfr. membrane-associated mucin-1), but failed to address the presence of goblet cells. As goblet cells are responsible for the secretion of mucin 5AC, which is the most abundant mucin in the mucin la...
We read with interest the recent publication by Bertolin et al. (“In vitro establishment, validation and characterisation of conjunctival epithelium outgrowth using tissue fragments and amniotic membrane”). Their validated conjunctival analogue of the simple limbal epithelial transplantation does represent a promising advance in the field. It is, however, interesting to note that the established tissue application was mainly validated on its growth potential and not specifically on its ability to reinstate a healthy ocular mucosal surface.
Functional validation is of utmost importance, especially as the glued fragments are directly transplanted. This approach circumvents the need for expensive cell culture but also bypasses the stringent release criteria for cell therapies or tissue-engineered transplantation products. We would suggest that before this technique can be considered fully validated, it should be demonstrated that the obtained conjunctival cells contribute to the first line of mucosal defence, i.e. barrier formation. Several conjunctival barriers can be identified, such as intercellular junction complexes, glycocalyx and secreted mucins. Bertolin et al. demonstrated the presence of tight junctions (cfr. ZO-1 protein) and a glycocalyx (cfr. membrane-associated mucin-1), but failed to address the presence of goblet cells. As goblet cells are responsible for the secretion of mucin 5AC, which is the most abundant mucin in the mucin layer of the tear film, its presence is crucial to obtain a normal, hydrated ocular surface. Presence of mucin-producing goblet cells is so characteristic of the conjunctiva that it is a cardinal feature of impression cytology techniques in the diagnosis of corneal limbal stem cell deficiency. We therefore consider goblet cells (and their associated mucin production) in 2D and 3D cultures the “sine qua non” for conjunctival epithelium and propose that it should be a core element of the validated characterization process.
As functional goblet cells are difficult to maintain in culture, it could be debated that the absence of goblet cells in the outgrowth does not implicate their absence during in vivo expansion. If conjunctival stem cells in the outgrowth could be shown to have bipotent properties, it is reasonable to assume that conjunctival goblet cells can differentiate from these bipotent stem cells and that they can be preserved once they are placed in their natural tightly regulated environment, including the conjunctival innervation of the epithelium. Do the authors have any experience with goblet cell maturation? In any case, these properties would have to be well proven before this technique can be relied on in the clinic.
Affiliations:
Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
Conflicts of Interest Disclosure:
APT: Consultant to Ivantis, Sandoz, and Zeiss
Acknowledgment:
APT is supported by an unrestricted departmental grant from Research to Prevent Blindness, NY, NY
Corresponding Author:
Angelo P. Tanna, M.D.
Department of Ophthalmology
Northwestern University Feinberg School of Medicine
645 N. Michigan Ave., Suite 440
Chicago, IL 60611
Telephone: 312-908-8152
Fax: 312-503-8152
E-mail: atanna@northwestern.edu
Dear Editor:
I read with interest the work of Doctor Hashimoto and colleagues on the risk of adverse neonatal outcomes (congenital anomalies, preterm birth, low birth weight) associated with maternal exposure to intraocular pressure-lowering medications during pregnancy.1 They used a large Japanese claims database and state-of-the-art statistical methodology to evaluate the frequency of adverse events in a cohort of live births of 91 women who had “at least one dispensation of IOP-lowering medications during the first trimester,” compared to that observed in 735 women with glaucoma or...
Affiliations:
Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
Conflicts of Interest Disclosure:
APT: Consultant to Ivantis, Sandoz, and Zeiss
Acknowledgment:
APT is supported by an unrestricted departmental grant from Research to Prevent Blindness, NY, NY
Corresponding Author:
Angelo P. Tanna, M.D.
Department of Ophthalmology
Northwestern University Feinberg School of Medicine
645 N. Michigan Ave., Suite 440
Chicago, IL 60611
Telephone: 312-908-8152
Fax: 312-503-8152
E-mail: atanna@northwestern.edu
Dear Editor:
I read with interest the work of Doctor Hashimoto and colleagues on the risk of adverse neonatal outcomes (congenital anomalies, preterm birth, low birth weight) associated with maternal exposure to intraocular pressure-lowering medications during pregnancy.1 They used a large Japanese claims database and state-of-the-art statistical methodology to evaluate the frequency of adverse events in a cohort of live births of 91 women who had “at least one dispensation of IOP-lowering medications during the first trimester,” compared to that observed in 735 women with glaucoma or suspicion of glaucoma who did not have such an exposure.
The authors discuss the previously used and outdated United States Food and Drug Administration (FDA) risk classification system for drugs used during pregnancy. The FDA required the removal of the pregnancy letter categories – A, B, C, D, and X from all drug product labels in 2015. Instead, for systemically absorbed drugs (which includes all ocular hypotensive medications), the FDA requires labeling to include a summary of the risks of using a drug during pregnancy as well as “risk statements based on data from all relevant sources (human, animal, and/or pharmacologic), that describe, for the drug, the risk of adverse developmental outcomes.”2
The investigators observed any adverse outcome in 17.6% of neonates with and in 13.3% without fetal exposure to IOP-lowering medications. The authors concluded that after propensity score adjustment, IOP-lowering medications were not significantly associated with more frequent adverse events. For example, the adjusted odds ratio for congenital anomalies was 1.43 (95% CI, 0.66 to 3.12).
The investigators only evaluated live births; therefore, the potentially increased risk of spontaneous abortion or fetal demise associated with the use of these agents during pregnancy cannot be known from this analysis. It is possible some of the women in the control cohort may have been exposed to ocular hypotensive agent(s) during the first trimester, using medication already in their possession, without necessarily having been dispensed any such agent during the first trimester. This could confound the comparative analysis.
Finally, the authors report their study had a power > 80% for detecting a two-fold increase in the composite outcome (i.e., the risk of any of the adverse neonatal outcomes studied). This begs the question: How much increased risk is a pregnant woman willing to accept? I believe a much lower threshold is necessary to arrive at a meaningful conclusion. In my experience, many women would reject even a 1% increase in the risk of a congenital anomaly. So then, the concluding message in the abstract that “IOP-lowering medications during the first trimester were not significantly associated with increase in congenital anomalies, preterm birth or low birth weight” is not meaningfully supported by the data. The study only supports the concept that the use of these medications is probably not associated with a doubling of the risk. Patients and society are interested in a higher threshold of safety.
Fortunately, pregnancy is often associated with a spontaneous reduction in intraocular pressure (IOP)4; therefore, continued treatment may not be required. Selective laser trabeculoplasty is also an option to consider for some patients. Moreover, many young patients with glaucoma can tolerate nine months of higher IOP.
Glaucoma in pregnancy is a complex problem that requires complex, collaborative decision-making. Pregnant women, their ophthalmologists and obstetricians must evaluate the potential risks associated with continued use of ocular hypotensive agents during pregnancy and weigh those against the risks of modifying or stopping therapy. I congratulate the authors on exploring this important topic and encourage others to conduct similar studies. Eventually, a meta-analysis may yield evidence that can guide clinical decision-making.
REFERENCES:
1. Hashimoto Y, Michihata N, Yamana H, Shigemi D, Morita K, Matsui H, Yasunaga H, Aihara M. Intraocular pressure-lowering medications during pregnancy and risk of neonatal adverse outcomes: a propensity score analysis using a large database. Br J Ophthalmol. 2021 Oct;105(10):1390-1394. doi: 10.1136/bjophthalmol-2020-316198. Epub 2020 Sep 9. PMID: 32907812.
2. Content and Format of Labeling for Human Prescription Drug and Biological Products;
Requirements for Pregnancy and Lactation Labeling. Department of Health and Human Services. Food and Drug Administration 21 CFR Part 201 [Docket No. FDA-2006-N-0515] RIN 0910-AF11. Available online at http://federalregister.gov/a/2014-28241.
3. Mezawa H, Tomotaki A, Yamamoto-Hanada K, Ishitsuka K, Ayabe T, Konishi M, Saito M, Yang L, Suganuma N, Hirahara F, Nakayama SF, Saito H, Ohya Y. Prevalence of Congenital Anomalies in the Japan Environment and Children's Study. J Epidemiol. 2019 Jul 5;29(7):247-256. doi: 10.2188/jea.JE20180014. Epub 2018 Sep 22. PMID: 30249945; PMCID: PMC6556438.
4. Ziai N, Ory SJ, Khan AR, Brubaker RF. Beta-human chorionic gonadotropin, progesterone, and aqueous dynamics during pregnancy. Arch Ophthalmol. 1994 Jun;112(6):801-6. doi: 10.1001/archopht.1994.01090180099043. PMID: 8002840.
I read with interest the paper by Gagrani and colleagues, regarding the self-characterisation of visual field loss by glaucoma patients, and the development of an app to allow this to be measured.1
The study helps to further understand the experience of glaucoma patients. Their experimental results support the view that patients experience their visual field defects as blur rather than 'black holes'. Hu et al found the most common subjective symptoms in glaucoma were "needing more light" (57%) and "blurry vision" (55%).2 In the study by Gagrani et al., subjects were able to modify both dimness and blur, though in practice they did not choose to use the dimness response at all.
It is possible that differences in the measurement tools might potentially influence these findings. For example, patients may have found the dim response more difficult to use.
The potential for this app to allow patients to better understand and self-pictoralise their visual disability is poignant and important. It will be interesting to see whether this novel approach yields similar results when replicated in future.
References
1. Gagrani M, Ndulue J, Anderson D, Kedar S, Gulati V, Shepherd J, et al. What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss. Br J Ophthalmol. 2020 Nov 20.
2. Hu CX, Zangalli C, Hsieh M, et al. What do patients with glaucoma see? Visual symptoms...
I read with interest the paper by Gagrani and colleagues, regarding the self-characterisation of visual field loss by glaucoma patients, and the development of an app to allow this to be measured.1
The study helps to further understand the experience of glaucoma patients. Their experimental results support the view that patients experience their visual field defects as blur rather than 'black holes'. Hu et al found the most common subjective symptoms in glaucoma were "needing more light" (57%) and "blurry vision" (55%).2 In the study by Gagrani et al., subjects were able to modify both dimness and blur, though in practice they did not choose to use the dimness response at all.
It is possible that differences in the measurement tools might potentially influence these findings. For example, patients may have found the dim response more difficult to use.
The potential for this app to allow patients to better understand and self-pictoralise their visual disability is poignant and important. It will be interesting to see whether this novel approach yields similar results when replicated in future.
References
1. Gagrani M, Ndulue J, Anderson D, Kedar S, Gulati V, Shepherd J, et al. What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss. Br J Ophthalmol. 2020 Nov 20.
2. Hu CX, Zangalli C, Hsieh M, et al. What do patients with glaucoma see? Visual symptoms reported by patients with glaucoma. Am J Med Sci 2014;348:403–9.
We read with interest the study by Silva and colleagues.[1] The authors investigate the prognostic potential of B-scan ultrasonography, visual electrophysiology and perioperative videoendoscopy (VE) for 13 patients undergoing keratoprosthesis (KPro) surgery and identified perioperative intraocular VE as a predictor of functional visual outcome at 1-year follow-up.[1] While we find this study interesting, we would like to caution against the interpretation and over-generalization of the findings reported therein.
Negative predictive value (NPV) was as defined as the number of patients with abnormal VE findings and subsequent unsatisfactory visual acuity over all patients with unfavourable VE. The authors report a NPV of 50% in 10 patients. By contrast, they report a positive predictive value (PPV) of 100% for this test.[1] Although a high PPV, as reported by the authors, is of great importance when deciding which patients are appropriate KPro candidates preoperatively, once the patient is undergoing surgery, we believe identifying patients at highest risk of poor visual outcome using NPV is more clinically relevant. The small sample size of 10 patients with a low prevalence of patients with unsatisfactory post-operative visual acuity, and NPV of 50% are important limitations of this study. From these findings, we are unable to justify VE's clinical benefit to the surgeon and their patient at the time of surgery. This is especially true give...
We read with interest the study by Silva and colleagues.[1] The authors investigate the prognostic potential of B-scan ultrasonography, visual electrophysiology and perioperative videoendoscopy (VE) for 13 patients undergoing keratoprosthesis (KPro) surgery and identified perioperative intraocular VE as a predictor of functional visual outcome at 1-year follow-up.[1] While we find this study interesting, we would like to caution against the interpretation and over-generalization of the findings reported therein.
Negative predictive value (NPV) was as defined as the number of patients with abnormal VE findings and subsequent unsatisfactory visual acuity over all patients with unfavourable VE. The authors report a NPV of 50% in 10 patients. By contrast, they report a positive predictive value (PPV) of 100% for this test.[1] Although a high PPV, as reported by the authors, is of great importance when deciding which patients are appropriate KPro candidates preoperatively, once the patient is undergoing surgery, we believe identifying patients at highest risk of poor visual outcome using NPV is more clinically relevant. The small sample size of 10 patients with a low prevalence of patients with unsatisfactory post-operative visual acuity, and NPV of 50% are important limitations of this study. From these findings, we are unable to justify VE's clinical benefit to the surgeon and their patient at the time of surgery. This is especially true given the invasive nature, cost and associated complications of this ancillary test. In addition to the risk of elevated intraocular pressure and cataract formation as outlined by the authors, the use of perioperative VE increases the risk of iatrogenic retinal tears, vitreous hemorrhage, and wound leaks,[2] not to mention the risk of retrobulbar anaesthesia,[3] all of which are morbid complications in KPro eyes. Moreover, 23% of the patient cohort (n=3) were excluded from analysis due to technical issues relating to perioperative VE. This highlights the additional challenges this ancillary test may present to the surgeon and their team.
Although prognosticating the visual outcomes of KPro and identifying which patients are at highest risk of KPro failure remain important areas of research and discussion, we believe the data presented by the authors are insufficient to position VE as a predictive perioperative ancillary test and urge readers to consider the associated risks to the patient and medical costs to the healthcare system. B-scan ultrasonography is widely accepted as the gold-standard preoperative imaging modality used to assess the posterior segment in eyes with severe and dense anterior segment opacities.[4] After reading this study, we believe that B-scan ultrasonography remains the method of choice for KPro preoperative evaluations.
References:
1. Silva, L. D. et al. B-scan ultrasound, visual electrophysiology and perioperative videoendoscopy for predicting functional results in keratoprosthesis candidates. Br. J. Ophthalmol. (2020).
2. Nagiel, A. et al. VISUAL AND ANATOMIC OUTCOMES OF PEDIATRIC ENDOSCOPIC VITRECTOMY IN 326 CASES. Retina (2020).
3. Hamilton, R. C. A discourse on the complications of retrobulbar and peribulbar blockade. Can. J. Ophthalmol. (2000).
4. Williamson, S. L. & Cortina, M. S. Boston type 1 keratoprosthesis from patient selection through postoperative management: A review for the keratoprosthetic surgeon. Clinical Ophthalmology (2016).
Luzia Diegues Silva MD1, Albert Santos MD1, Flávio Eduardo Hirai MD. Ph.D1, Norma Allemann MD1,2, Adriana Berezovsky Ph.D1, Solange Rios Salomão Ph.D1, Paulo Ricardo Chaves de Oliveira MD1, Gabriel Costa de Andrade MD1, Andre Maia MD1, Luciene Barbosa de Sousa MD1, Lauro Augusto de Oliveira MD. Ph.D.1,*
1 Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil
2 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
Corresponding author: Lauro Augusto de Oliveira
Dear Editor,
We read with interest the comments about our article by Anchouche and associates.
We agree with the authors that B-scan ultrasonography is widely accepted as the gold-standard preoperative imaging modality used to assess the posterior segment in eyes with severe and dense anterior segment opacities and it has been proven to be a useful tool in the preoperative evaluation of Kpro candidates. We also agree that it is safer, cheaper and a less invasive procedure when compared to VE. However, this image modality offers mostly anatomical information and less functional prognosis prediction when compared to direct visualization of the posterior segment achieved with VE.[1]
We are aware and agree with the authors’ concern regarding the invasive nature, the risk of elevated intraocular pressure, and cataract formation as discussed in our work. However, as it is clearly described in our manuscript,...
Luzia Diegues Silva MD1, Albert Santos MD1, Flávio Eduardo Hirai MD. Ph.D1, Norma Allemann MD1,2, Adriana Berezovsky Ph.D1, Solange Rios Salomão Ph.D1, Paulo Ricardo Chaves de Oliveira MD1, Gabriel Costa de Andrade MD1, Andre Maia MD1, Luciene Barbosa de Sousa MD1, Lauro Augusto de Oliveira MD. Ph.D.1,*
1 Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil
2 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
Corresponding author: Lauro Augusto de Oliveira
Dear Editor,
We read with interest the comments about our article by Anchouche and associates.
We agree with the authors that B-scan ultrasonography is widely accepted as the gold-standard preoperative imaging modality used to assess the posterior segment in eyes with severe and dense anterior segment opacities and it has been proven to be a useful tool in the preoperative evaluation of Kpro candidates. We also agree that it is safer, cheaper and a less invasive procedure when compared to VE. However, this image modality offers mostly anatomical information and less functional prognosis prediction when compared to direct visualization of the posterior segment achieved with VE.[1]
We are aware and agree with the authors’ concern regarding the invasive nature, the risk of elevated intraocular pressure, and cataract formation as discussed in our work. However, as it is clearly described in our manuscript, the VE test was performed perioperatively and did not hinder the surgical decision to proceed with KPro surgery. There was no additional anesthesia risk. Cataract formation was not a concern in this scenario because all Kpro candidates in our series would have their lens removed.
The study does have limitations such as the sample size. But this series allowed for an overall better understanding of the endoscopic findings and their usefulness, particularly with the comparative metrics between the preoperative data and postoperative results.
Optimizing the use of keratoprosthesis as an alternative for corneal blindness is challenging in contexts in which the device is not available or affordable. This is a difficult decision faced by surgeons daily, especially in limited-resource settings such as ours. We will continue to investigate strategies for predicting prognosis to allow us to be more precise in the selection of treatment. We agree with the authors that our findings should not be over-generalized. Ideally one cannot deny keratoprosthesis implantation based on unfavourable findings noted on videoendoscopy, but regarding prognostication, we would counsel these patients on potential visual outcomes.
1. Farias CC, Ozturk HE, Albini TA, et al. Use of intraocular video endoscopic examination in the preoperative evaluation of keratoprosthesis surgery to assess visual potential. Am J Ophthalmol 2014;158:80-6.
Thank you for raising the issue of abbreviations entering the virological lexicon which might give rise to confusion and misunderstanding. Over a decade has elapsed since our patient report was published and the source material is not retrievable. However, our recollection is the patient was discussed contemporaneously at the MDT and the viral aetiology, radiology findings and medical management determined and documented, from which the data was sourced for the 2008 report. Plausible as it may seem, it is not possible to test the veracity of the suggestion that the names ‘Jamestown Canyon’ and ‘John Cunningham’ might have been transposed during that MDT many years after the event, paper records are not kept indefinitely in NHS practice and ethics in medical publishing demands that patient identifiers are not described or retained in order to preserve anonymity. Perhaps the latter should have been considered over half a century ago when JC virus was first identified in the brain of the unfortunate patient after whom the eponymous pathogen was christened
(Padgett BL, Walker DL; et al. (1971). "Cultivation of papova-like virus from human brain with progressive multifocal leucoencephalopathy". Lancet. 1 (7712):
1257–60. doi:10.1016/S0140-6736(71)91777-6)
In their 2008 case report, Muqit, et al. describe a case of “presumptive Jamestown Canyon viral retinitis.”1
Jamestown Canyon virus is a mosquito-borne, single-stranded, ribonucleic acid (RNA) orthobunyavirus that is endemic throughout much of North America.2,3 Infection with Jamestown Canyon virus may be asymptomatic or may result in a general febrile illness, meningitis, and/or meningoencephalitis.2,3 Beyond the above case report by Muqit, et al.,1 and another review article referencing this case report,4 Jamestown Canyon virus has not been reported to cause retinitis or other ocular manifestations.
Upon close review of the case report by Muqit, et al.,1 we believe the authors are likely describing a case of John Cunningham (JC) virus (a ubiquitous, double-stranded, deoxyribonucleic acid [DNA] human polyomavirus known to cause progressive multifocal leukoencephalopathy [PML] among the immunocompromised)5-7 rather than Jamestown Canyon virus.
First, the case patient with viral retinitis had underlying human immunodeficiency virus (HIV) infection and a low CD4 lymphocyte count (240 cells/mm3), making him immunocompromised and susceptible to reactivation of the John Cunningham (JC) virus. Second, the case patient had magnetic resonance imaging (MRI) brain findings (i.e., asymmetric, predominantly posterior, confluent, subcortical white matter hyperintensities involving U-fibers) that are classic for John Cunningham (JC) virus-related PML.6,7 In fact,...
In their 2008 case report, Muqit, et al. describe a case of “presumptive Jamestown Canyon viral retinitis.”1
Jamestown Canyon virus is a mosquito-borne, single-stranded, ribonucleic acid (RNA) orthobunyavirus that is endemic throughout much of North America.2,3 Infection with Jamestown Canyon virus may be asymptomatic or may result in a general febrile illness, meningitis, and/or meningoencephalitis.2,3 Beyond the above case report by Muqit, et al.,1 and another review article referencing this case report,4 Jamestown Canyon virus has not been reported to cause retinitis or other ocular manifestations.
Upon close review of the case report by Muqit, et al.,1 we believe the authors are likely describing a case of John Cunningham (JC) virus (a ubiquitous, double-stranded, deoxyribonucleic acid [DNA] human polyomavirus known to cause progressive multifocal leukoencephalopathy [PML] among the immunocompromised)5-7 rather than Jamestown Canyon virus.
First, the case patient with viral retinitis had underlying human immunodeficiency virus (HIV) infection and a low CD4 lymphocyte count (240 cells/mm3), making him immunocompromised and susceptible to reactivation of the John Cunningham (JC) virus. Second, the case patient had magnetic resonance imaging (MRI) brain findings (i.e., asymmetric, predominantly posterior, confluent, subcortical white matter hyperintensities involving U-fibers) that are classic for John Cunningham (JC) virus-related PML.6,7 In fact, the authors claimed that the MRI brain findings were “confirmatory of the underlying diagnosis.”1 No MRI brain findings are classic or confirmatory for Jamestown Canyon virus infection. Third, the case patient’s cerebrospinal fluid was reportedly positive for viral DNA by polymerase chain reaction. This could only be possible for a DNA virus (i.e., John Cunningham (JC) virus) and not an RNA virus (i.e., Jamestown Canyon virus). Fourth, recovery of John Cunningham (JC) viral nucleic acid from ocular tissues of HIV-infected patients has been previously reported, so there is already precedent for this virus to infect the eye.8 Finally, the case patient had no known travel to or any mosquito exposure in North America, where Jamestown Canyon virus is endemic.2,3
Given John Cunningham (JC) and Jamestown Canyon viruses have different virology, epidemiology, and clinical manifestations, we believe the viruses were mistaken for one another because they share the same first letters of their words (i.e., J and C) and their abbreviations were likely confused. If our suspicion is correct, this case report highlights the possible dangers of abbreviations in medicine and the need to clearly define potentially confusing abbreviations in medical literature.
References
1. Muqit MM, Devonport H, Smith RA, Dhillon B. Presumptive Jamestown Canyon viral retinitis. Br J Ophthalmol. 2008 Dec;92(12):1599-600, 1695-6. doi: 10.1136/bjo.2007.132902. PMID: 19029162.
2. Coleman KJ, Chauhan L, Piquet AL, Tyler KL, Pastula DM. An Overview of Jamestown Canyon Virus Disease. Neurohospitalist. 2021 Jul;11(3):277-278. doi: 10.1177/19418744211005948. Epub 2021 Mar 29. PMID: 34163560; PMCID: PMC8182404.
3. Pastula DM, Hoang Johnson DK, White JL, Dupuis AP 2nd, Fischer M, Staples JE. Jamestown Canyon Virus Disease in the United States-2000-2013. Am J Trop Med Hyg. 2015 Aug;93(2):384-9. doi: 10.4269/ajtmh.15-0196. Epub 2015 Jun 1. PMID: 26033022; PMCID: PMC4530766.
4. Karesh JW, Mazzoli RA, Heintz SK. Ocular Manifestations of Mosquito-Transmitted Diseases. Mil Med. 2018 Mar 1;183(suppl_1):450-458. doi: 10.1093/milmed/usx183. PMID: 29635625.
5. Padgett BL, Walker DL, ZuRhein GM, Eckroade RJ, Dessel BH. Cultivation of papova-like virus from human brain with progressive multifocal leucoencephalopathy. Lancet. 1971 Jun 19;1(7712):1257-60. doi: 10.1016/s0140-6736(71)91777-6. PMID: 4104715.
6. Grebenciucova E, Berger JR. Progressive Multifocal Leukoencephalopathy. Neurol Clin. 2018 Nov;36(4):739-750. doi: 10.1016/j.ncl.2018.06.002. PMID: 30366552.
7. Pinto M, Dobson S. BK and JC virus: a review. J Infect. 2014 Jan;68 Suppl 1:S2-8. doi: 10.1016/j.jinf.2013.09.009. Epub 2013 Oct 8. PMID: 24119828.
8. Eberwein P, Hansen LL, Agostini HT. Genotypes of JC virus, DNA of cytomegalovirus, and proviral DNA of human immunodeficiency virus in eyes of acquired immunodeficiency syndrome patients. J Neurovirol. 2005 Feb;11(1):58-65. doi: 10.1080/13550280590900391. PMID: 15804960.
We read with great interest the article by Forte et al1, "Swept source optical Coherence tomography Angiography in patients treated with hydroxychloroquine: co-relation of the functional and morphological test." Hydroxychloroquine (HCQ) is a widely used drug for the management of systemic lupus erythematosus and rheumatoid arthritis. Non-invasive tests like optical coherence tomography, optical coherence tomography-angiography, 10-2 visual fields and multifocal ERG (mf-ERG) help in the early detection of the toxicity.2 We would like to highlight here importance of adaptive optics, and various studies done for the early detection of HCQ toxicity. In the study by Forte et al, mf-ERG did not co-relate with the flow changes on OCT-A, however in another observation by Penrose et al (n=6) a depression of signals on multifocal ERG was found in the perifoveal region even when the patients had normal visual acuity and a normal fundus.3Costa et al found significant differences between the micro-perimetry in the patients taking hydroxychloroquine and controls.4 It will be interesting to know the authors take on this. Besides these, adaptive optics is emerging as an important tool to detect the early photo-receptor changes in patients with HCQ toxicity. Adaptive optics help in the direct visualization of the cone mosaic. Stepien et al in their observation on 4 patients observed that adaptive optics showed a loss of cone mosaic in the perifoveal region that corresponded with...
We read with great interest the article by Forte et al1, "Swept source optical Coherence tomography Angiography in patients treated with hydroxychloroquine: co-relation of the functional and morphological test." Hydroxychloroquine (HCQ) is a widely used drug for the management of systemic lupus erythematosus and rheumatoid arthritis. Non-invasive tests like optical coherence tomography, optical coherence tomography-angiography, 10-2 visual fields and multifocal ERG (mf-ERG) help in the early detection of the toxicity.2 We would like to highlight here importance of adaptive optics, and various studies done for the early detection of HCQ toxicity. In the study by Forte et al, mf-ERG did not co-relate with the flow changes on OCT-A, however in another observation by Penrose et al (n=6) a depression of signals on multifocal ERG was found in the perifoveal region even when the patients had normal visual acuity and a normal fundus.3Costa et al found significant differences between the micro-perimetry in the patients taking hydroxychloroquine and controls.4 It will be interesting to know the authors take on this. Besides these, adaptive optics is emerging as an important tool to detect the early photo-receptor changes in patients with HCQ toxicity. Adaptive optics help in the direct visualization of the cone mosaic. Stepien et al in their observation on 4 patients observed that adaptive optics showed a loss of cone mosaic in the perifoveal region that corresponded with the OCT findings. OCT findings in their study showed a loss of IS -OS junction with preservation of retinal pigment epithelium and external limiting membrane showing a "sinking hole defect". SD-OCT and adaptive optics also showed defects in the area which were unaffected on 10-2 perimetry, suggesting pre-clinical loss. 5 Similarly, Debellemanière G et al, in their study on eyes found that there was increased cone spacing and moderate cone loss with an increasing cumulative dose of HCQ.6 It will be interesting to know the author's point of view about this, Thus to conclude, the non-invasive investigations may aid in the early detection of HCQ toxicity.
References
1. Forte R, Haulani H, Dyrda A, et al
Swept source optical coherence tomography angiography in patients treated with hydroxychloroquine: correlation with morphological and functional tests. British Journal of Ophthalmology 2021;105:1297-1301.
2. Marmor MF, Kellner U, Lai TY, Melles RB, Mieler WF; American Academy of Ophthalmology. Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision). Ophthalmology. 2016 Jun;123(6):1386-94
3. Penrose PJ, Tzekov RT, Sutter EE, Fu AD, Allen AW Jr, Fung WE, Oxford KW. Multifocal electroretinography evaluation for early detection of retinal dysfunction in patients taking hydroxychloroquine. Retina. 2003 Aug;23(4):503-12.
4. Martínez-Costa L, Victoria Ibañez M, Murcia-Bello C, Epifanio I, Verdejo-Gimeno C, Beltrán-Catalán E, Marco-Ventura P. Use of microperimetry to evaluate hydroxychloroquine and chloroquine retinal toxicity. Can J Ophthalmol. 2013 Oct;48(5):400-5. doi: 10.1016/j.jcjo.2013.03.018. PMID: 24093187.
5. Stepien KE, Han DP, Schell J, Godara P, Rha J, Carroll J. Spectral-domain optical coherence tomography and adaptive optics may detect hydroxychloroquine retinal toxicity before symptomatic vision loss. Trans Am Ophthalmol Soc. 2009 Dec;107:28-33. PMID: 20126479; PMCID: PMC2814561.
6. Debellemanière G, Flores M, Tumahai P, Meillat M, Bidaut Garnier M, Delbosc B, Saleh M. Assessment of parafoveal cone density in patients taking hydroxychloroquine in the absence of clinically documented retinal toxicity. Acta Ophthalmol. 2015 Nov;93(7):e534-40
Eyes with Fuchs endothelial corneal dystrophy (FECD) are known to have reduced contrast vision from increased glare even if high-contrast acuity is not affected.1 In a retrospective study, Augustin and colleagues suggested that corneal guttae without edema contribute to decreased contrast sensitivity, and that such eyes would benefit from Descemet membrane endothelial keratoplasty (DMEK).2 The topic is important because it is unknown whether guttae in the absence of any corneal edema affect vision and therefore whether such eyes truly benefit from DMEK. The authors enrolled eyes with >5 mm of confluent guttae and without edema (modified Krachmer grade 5); however, they did not state their definition of “edema”. In FECD, when corneal edema is not clinically detectable by slit-lamp examination, it can be detected by Scheimpflug tomography.3 A recent study found evidence of subclinical corneal edema in 88% of eyes with FECD grade 5 and almost 40% of eyes with lesser grades of FECD.4 It is therefore highly likely that many of the FECD eyes examined by Augustin and colleagues did in fact have subclinical corneal edema, so can the authors examine the Scheimpflug tomograms of these eyes and report the contrast sensitivity results based on the presence or absence of subclinical edema? This is important because reduced contrast sensitivity might be caused by subclinical edema and not simply by “guttae without edema”, and cornea surgeons should not conclude that it is appr...
Eyes with Fuchs endothelial corneal dystrophy (FECD) are known to have reduced contrast vision from increased glare even if high-contrast acuity is not affected.1 In a retrospective study, Augustin and colleagues suggested that corneal guttae without edema contribute to decreased contrast sensitivity, and that such eyes would benefit from Descemet membrane endothelial keratoplasty (DMEK).2 The topic is important because it is unknown whether guttae in the absence of any corneal edema affect vision and therefore whether such eyes truly benefit from DMEK. The authors enrolled eyes with >5 mm of confluent guttae and without edema (modified Krachmer grade 5); however, they did not state their definition of “edema”. In FECD, when corneal edema is not clinically detectable by slit-lamp examination, it can be detected by Scheimpflug tomography.3 A recent study found evidence of subclinical corneal edema in 88% of eyes with FECD grade 5 and almost 40% of eyes with lesser grades of FECD.4 It is therefore highly likely that many of the FECD eyes examined by Augustin and colleagues did in fact have subclinical corneal edema, so can the authors examine the Scheimpflug tomograms of these eyes and report the contrast sensitivity results based on the presence or absence of subclinical edema? This is important because reduced contrast sensitivity might be caused by subclinical edema and not simply by “guttae without edema”, and cornea surgeons should not conclude that it is appropriate to offer DMEK for any eye with guttae. Surgeons and clinicians should recognize that Scheimpflug tomography patterns, which are easily acquired and repeatable,5 are more helpful than guttae assessment for guiding clinical decision-making in FECD.4
References
1. van der Meulen IJ, Patel SV, Lapid-Gortzak R, Nieuwendaal CP, McLaren JW, van den Berg TJ. Quality of vision in patients with Fuchs endothelial dystrophy and after Descemet stripping endothelial keratoplasty. Arch Ophthalmol 2011;129:1537-1542.
2. Augustin VA, Weller JM, Kruse FE, Tourtas T. Influence of corneal guttae and nuclear cataract on contrast sensitivity. Br J Ophthalmol 2020.
3. Sun SY, Wacker K, Baratz KH, Patel SV. Determining Subclinical Edema in Fuchs Endothelial Corneal Dystrophy. Revised Classification using Scheimpflug Tomography for Preoperative Assessment. Ophthalmology 2019;126:195-204.
4. Patel SV, Hodge DO, Treichel EJ, Spiegel MR, Baratz KH. Predicting the Prognosis of Fuchs Endothelial Corneal Dystrophy by using Scheimpflug Tomography. Ophthalmology 2020;127:315-323.
5. Patel SV, Hodge DO, Treichel EJ, Spiegel MR, Baratz KH. Repeatability of Scheimpflug Tomography for Assessing Fuchs Endothelial Corneal Dystrophy. Am J Ophthalmol 2020;215:91-103.
We read with interest the article by Sarker et al(1) in which they compared the outcomes of trabeculectomy versus Ahmed glaucoma valve (AGV) implantation in Sturge–Weber syndrome (SWS) patients with secondary glaucoma aged 11-62 years. As it noted in the paper, the authors found that complete success rates after 24 months were 80% and 70% in the AGV and trabeculectomy groups, respectively, and qualified success rates were 90% and 85% at same period in the AGV and trabeculectomy groups, respectively. We were delighted to get the conclusion that both AGV implant and trabeculectomy appeared to be safe and efficacious in controlling glaucoma secondary to SWS.
Show MoreAs it reported by Mohamed et al., the complete success rate and qualified success rate (intraocular pressure≤17mmHg) of trabeculectomy reported were 80% and 100% at 12 postoperative follow-up month, respectively(2). However, the qualified success rate (90%) of AGV implantation in SWS patients with secondary glaucoma is higher than that reported by Hamush et al. (79%)(3) and Kaushik et al. (76%)(4) at 2 years of follow-up. Meanwhile, the trabeculectomy with MMC success rate in this study was comparable to other studies about primary glaucoma(5, 6), but the success rate of tube shunt surgery was higher than in prior reports. The qualified success rate of Baerveldt implantation for patients who not had undergone previous incisional ocular surgery was 73% in Primary Tube Versus Trabeculectomy (PTVT) study(6) and 75% rep...
To the editor,
We read with interest the recent publication by Bertolin et al. (“In vitro establishment, validation and characterisation of conjunctival epithelium outgrowth using tissue fragments and amniotic membrane”). Their validated conjunctival analogue of the simple limbal epithelial transplantation does represent a promising advance in the field. It is, however, interesting to note that the established tissue application was mainly validated on its growth potential and not specifically on its ability to reinstate a healthy ocular mucosal surface.
Functional validation is of utmost importance, especially as the glued fragments are directly transplanted. This approach circumvents the need for expensive cell culture but also bypasses the stringent release criteria for cell therapies or tissue-engineered transplantation products. We would suggest that before this technique can be considered fully validated, it should be demonstrated that the obtained conjunctival cells contribute to the first line of mucosal defence, i.e. barrier formation. Several conjunctival barriers can be identified, such as intercellular junction complexes, glycocalyx and secreted mucins. Bertolin et al. demonstrated the presence of tight junctions (cfr. ZO-1 protein) and a glycocalyx (cfr. membrane-associated mucin-1), but failed to address the presence of goblet cells. As goblet cells are responsible for the secretion of mucin 5AC, which is the most abundant mucin in the mucin la...
Show MoreTitle: Management of Glaucoma During Pregnancy
Author: Angelo P. Tanna
Affiliations:
Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA
Conflicts of Interest Disclosure:
APT: Consultant to Ivantis, Sandoz, and Zeiss
Acknowledgment:
APT is supported by an unrestricted departmental grant from Research to Prevent Blindness, NY, NY
Corresponding Author:
Angelo P. Tanna, M.D.
Department of Ophthalmology
Northwestern University Feinberg School of Medicine
645 N. Michigan Ave., Suite 440
Chicago, IL 60611
Telephone: 312-908-8152
Fax: 312-503-8152
E-mail: atanna@northwestern.edu
Dear Editor:
I read with interest the work of Doctor Hashimoto and colleagues on the risk of adverse neonatal outcomes (congenital anomalies, preterm birth, low birth weight) associated with maternal exposure to intraocular pressure-lowering medications during pregnancy.1 They used a large Japanese claims database and state-of-the-art statistical methodology to evaluate the frequency of adverse events in a cohort of live births of 91 women who had “at least one dispensation of IOP-lowering medications during the first trimester,” compared to that observed in 735 women with glaucoma or...
Show MoreI read with interest the paper by Gagrani and colleagues, regarding the self-characterisation of visual field loss by glaucoma patients, and the development of an app to allow this to be measured.1
The study helps to further understand the experience of glaucoma patients. Their experimental results support the view that patients experience their visual field defects as blur rather than 'black holes'. Hu et al found the most common subjective symptoms in glaucoma were "needing more light" (57%) and "blurry vision" (55%).2 In the study by Gagrani et al., subjects were able to modify both dimness and blur, though in practice they did not choose to use the dimness response at all.
It is possible that differences in the measurement tools might potentially influence these findings. For example, patients may have found the dim response more difficult to use.
The potential for this app to allow patients to better understand and self-pictoralise their visual disability is poignant and important. It will be interesting to see whether this novel approach yields similar results when replicated in future.
References
Show More1. Gagrani M, Ndulue J, Anderson D, Kedar S, Gulati V, Shepherd J, et al. What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss. Br J Ophthalmol. 2020 Nov 20.
2. Hu CX, Zangalli C, Hsieh M, et al. What do patients with glaucoma see? Visual symptoms...
Dear Editor,
We read with interest the study by Silva and colleagues.[1] The authors investigate the prognostic potential of B-scan ultrasonography, visual electrophysiology and perioperative videoendoscopy (VE) for 13 patients undergoing keratoprosthesis (KPro) surgery and identified perioperative intraocular VE as a predictor of functional visual outcome at 1-year follow-up.[1] While we find this study interesting, we would like to caution against the interpretation and over-generalization of the findings reported therein.
Negative predictive value (NPV) was as defined as the number of patients with abnormal VE findings and subsequent unsatisfactory visual acuity over all patients with unfavourable VE. The authors report a NPV of 50% in 10 patients. By contrast, they report a positive predictive value (PPV) of 100% for this test.[1] Although a high PPV, as reported by the authors, is of great importance when deciding which patients are appropriate KPro candidates preoperatively, once the patient is undergoing surgery, we believe identifying patients at highest risk of poor visual outcome using NPV is more clinically relevant. The small sample size of 10 patients with a low prevalence of patients with unsatisfactory post-operative visual acuity, and NPV of 50% are important limitations of this study. From these findings, we are unable to justify VE's clinical benefit to the surgeon and their patient at the time of surgery. This is especially true give...
Show MoreLuzia Diegues Silva MD1, Albert Santos MD1, Flávio Eduardo Hirai MD. Ph.D1, Norma Allemann MD1,2, Adriana Berezovsky Ph.D1, Solange Rios Salomão Ph.D1, Paulo Ricardo Chaves de Oliveira MD1, Gabriel Costa de Andrade MD1, Andre Maia MD1, Luciene Barbosa de Sousa MD1, Lauro Augusto de Oliveira MD. Ph.D.1,*
1 Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil
2 Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
Corresponding author: Lauro Augusto de Oliveira
Dear Editor,
We read with interest the comments about our article by Anchouche and associates.
We agree with the authors that B-scan ultrasonography is widely accepted as the gold-standard preoperative imaging modality used to assess the posterior segment in eyes with severe and dense anterior segment opacities and it has been proven to be a useful tool in the preoperative evaluation of Kpro candidates. We also agree that it is safer, cheaper and a less invasive procedure when compared to VE. However, this image modality offers mostly anatomical information and less functional prognosis prediction when compared to direct visualization of the posterior segment achieved with VE.[1]
We are aware and agree with the authors’ concern regarding the invasive nature, the risk of elevated intraocular pressure, and cataract formation as discussed in our work. However, as it is clearly described in our manuscript,...
Show MoreThank you for raising the issue of abbreviations entering the virological lexicon which might give rise to confusion and misunderstanding. Over a decade has elapsed since our patient report was published and the source material is not retrievable. However, our recollection is the patient was discussed contemporaneously at the MDT and the viral aetiology, radiology findings and medical management determined and documented, from which the data was sourced for the 2008 report. Plausible as it may seem, it is not possible to test the veracity of the suggestion that the names ‘Jamestown Canyon’ and ‘John Cunningham’ might have been transposed during that MDT many years after the event, paper records are not kept indefinitely in NHS practice and ethics in medical publishing demands that patient identifiers are not described or retained in order to preserve anonymity. Perhaps the latter should have been considered over half a century ago when JC virus was first identified in the brain of the unfortunate patient after whom the eponymous pathogen was christened
(Padgett BL, Walker DL; et al. (1971). "Cultivation of papova-like virus from human brain with progressive multifocal leucoencephalopathy". Lancet. 1 (7712):
1257–60. doi:10.1016/S0140-6736(71)91777-6)
In their 2008 case report, Muqit, et al. describe a case of “presumptive Jamestown Canyon viral retinitis.”1
Jamestown Canyon virus is a mosquito-borne, single-stranded, ribonucleic acid (RNA) orthobunyavirus that is endemic throughout much of North America.2,3 Infection with Jamestown Canyon virus may be asymptomatic or may result in a general febrile illness, meningitis, and/or meningoencephalitis.2,3 Beyond the above case report by Muqit, et al.,1 and another review article referencing this case report,4 Jamestown Canyon virus has not been reported to cause retinitis or other ocular manifestations.
Upon close review of the case report by Muqit, et al.,1 we believe the authors are likely describing a case of John Cunningham (JC) virus (a ubiquitous, double-stranded, deoxyribonucleic acid [DNA] human polyomavirus known to cause progressive multifocal leukoencephalopathy [PML] among the immunocompromised)5-7 rather than Jamestown Canyon virus.
First, the case patient with viral retinitis had underlying human immunodeficiency virus (HIV) infection and a low CD4 lymphocyte count (240 cells/mm3), making him immunocompromised and susceptible to reactivation of the John Cunningham (JC) virus. Second, the case patient had magnetic resonance imaging (MRI) brain findings (i.e., asymmetric, predominantly posterior, confluent, subcortical white matter hyperintensities involving U-fibers) that are classic for John Cunningham (JC) virus-related PML.6,7 In fact,...
Show MoreWe read with great interest the article by Forte et al1, "Swept source optical Coherence tomography Angiography in patients treated with hydroxychloroquine: co-relation of the functional and morphological test." Hydroxychloroquine (HCQ) is a widely used drug for the management of systemic lupus erythematosus and rheumatoid arthritis. Non-invasive tests like optical coherence tomography, optical coherence tomography-angiography, 10-2 visual fields and multifocal ERG (mf-ERG) help in the early detection of the toxicity.2 We would like to highlight here importance of adaptive optics, and various studies done for the early detection of HCQ toxicity. In the study by Forte et al, mf-ERG did not co-relate with the flow changes on OCT-A, however in another observation by Penrose et al (n=6) a depression of signals on multifocal ERG was found in the perifoveal region even when the patients had normal visual acuity and a normal fundus.3Costa et al found significant differences between the micro-perimetry in the patients taking hydroxychloroquine and controls.4 It will be interesting to know the authors take on this. Besides these, adaptive optics is emerging as an important tool to detect the early photo-receptor changes in patients with HCQ toxicity. Adaptive optics help in the direct visualization of the cone mosaic. Stepien et al in their observation on 4 patients observed that adaptive optics showed a loss of cone mosaic in the perifoveal region that corresponded with...
Show MoreEyes with Fuchs endothelial corneal dystrophy (FECD) are known to have reduced contrast vision from increased glare even if high-contrast acuity is not affected.1 In a retrospective study, Augustin and colleagues suggested that corneal guttae without edema contribute to decreased contrast sensitivity, and that such eyes would benefit from Descemet membrane endothelial keratoplasty (DMEK).2 The topic is important because it is unknown whether guttae in the absence of any corneal edema affect vision and therefore whether such eyes truly benefit from DMEK. The authors enrolled eyes with >5 mm of confluent guttae and without edema (modified Krachmer grade 5); however, they did not state their definition of “edema”. In FECD, when corneal edema is not clinically detectable by slit-lamp examination, it can be detected by Scheimpflug tomography.3 A recent study found evidence of subclinical corneal edema in 88% of eyes with FECD grade 5 and almost 40% of eyes with lesser grades of FECD.4 It is therefore highly likely that many of the FECD eyes examined by Augustin and colleagues did in fact have subclinical corneal edema, so can the authors examine the Scheimpflug tomograms of these eyes and report the contrast sensitivity results based on the presence or absence of subclinical edema? This is important because reduced contrast sensitivity might be caused by subclinical edema and not simply by “guttae without edema”, and cornea surgeons should not conclude that it is appr...
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