We read with interest the recently published study by Kim et al, which the authors described as a cross-sectional, observational, case-control study. As a single study such a design is not possible since cross-sectional and case-control studies are two distinct types of study designs. The authors compared the percent with lower lid epiblepharon between those with and without congenital glaucoma and reported that controls were matched on age and date of outpatient visit to the cases, which would suggest this is a matched case-control study. However, the statistical analysis employed did not account for the matched nature of the study design and therefore was not appropriate. Statistical procedures that account for the matched nature of the study should have been employed. The authors are urged to conduct a reanalysis of their study, amending their interpretation as warranted.
Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema. Cicinelli et al. Br J Ophthalmol 2017; http: /dx.doi. org/ 10.1136/bjophthalmol-2017-310242.
Dear Editor
We would like to address several challenges that have arisen from the study by Cicinelli et al (1), which can be specifically summarized below.
1. The study was retrospectively conducted, with a selection bias attributable to the heterogeneity of the patients included, for example, six patients were affected by the type 1 diabetes mellitus; eighteen eyes were phakic; twenty seven eyes underwent cataract extraction and intraocular lens implant; and thirteen eyes received grid macular photocoagulation for diabetic macular oedema (DME) prior to ranibizumab (RNB).
2. After undergoing three loading-dose intravitreal injections of RNB performed at fixed 4-week intervals for the first 12 weeks, all the patients regardless of functional and anatomical characteristics, were shifted to dexamethasone implant (DEX implant 0.7 mg; Ozurdex; Allergan, Irvine, California, USA) continued at 4-month intervals until stable best-corrected visual acuity (BCVA) was reached. However, nothing was...
Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema. Cicinelli et al. Br J Ophthalmol 2017; http: /dx.doi. org/ 10.1136/bjophthalmol-2017-310242.
Dear Editor
We would like to address several challenges that have arisen from the study by Cicinelli et al (1), which can be specifically summarized below.
1. The study was retrospectively conducted, with a selection bias attributable to the heterogeneity of the patients included, for example, six patients were affected by the type 1 diabetes mellitus; eighteen eyes were phakic; twenty seven eyes underwent cataract extraction and intraocular lens implant; and thirteen eyes received grid macular photocoagulation for diabetic macular oedema (DME) prior to ranibizumab (RNB).
2. After undergoing three loading-dose intravitreal injections of RNB performed at fixed 4-week intervals for the first 12 weeks, all the patients regardless of functional and anatomical characteristics, were shifted to dexamethasone implant (DEX implant 0.7 mg; Ozurdex; Allergan, Irvine, California, USA) continued at 4-month intervals until stable best-corrected visual acuity (BCVA) was reached. However, nothing was stated as to whether there were patients with complete retinal dryness at week 12 and if so, why they were switched to dexamethasone implant.
3. In the assessment of the final results of this study we considered the current assertion that evaluation of outcomes has to be guided by anatomical measure data with visual changes as a secondary guide [2]. Accordingly, the final outcomes of this series were unsatisfactory. Specifically, despite a significant mean gain of 5.6 Early Treatment Diabetic Retinopathy Study (ETDRS) letters in BCVA score in poorly responding patients and an insignificant improvement of 2.1 ETDRS letters in patients with good visual response, the central macular thickness (CMT) decreased significantly to 363.6 microns and reduced insignificantly to 359 microns, in the poor and good responders, respectively. Of note, the both CMT values were more than the cutoff for the upper level of normal CMT [3], highlighting unresolved DME. Moreover, seven eyes developed intraocular pressure =/> 20 mm Hg, cataract progression was observed in nine among the phakic eyes (50%) during the study period, and two patients underwent cataract extraction after the dexamethasone implant. Importantly, persistence of unresolved macular oedema can permanently damage the outer retinal layers, leading to retinal fibrosis and macular atrophy, indicating that the disease process is still active and progressive, requiring further treatment with antiangiogenic agents.
4. As far as the potential prognosticatours of clinical outcome after dexamethasone implant are concerned, the following baseline characteristics should have been considered and included in a stepwise linear regression analysis along with those already presented, namely the subfoveal choroidal thickness, the qualitative status of the 4 outer retinal layers, the vitreoretinal interface abnormalities (vitreomacular adhesion/traction and epiretinal membrane), the diabetic retinopathy severity, the presence of macular ischemia on fluorescein angiography, and the duration of DME prior to therapy.
5. The specific anti-VEGF drugs (bevacizumab [Avastin; Genentech, South San Francisco, California, USA)/ranibizumab [Lucentis, Genentech]/aflibercept [Eylea; Regeneron Pharmaceuticals Inc, Tarrytown, New York, USA]) represent the front-line therapy for the treatment of DME but only the VEGF inhibition may not be sufficient to decrease inflammatory response. Therefore, addition of a non-specific anti-VEGF substance, ie. a corticosteroid implant, is mandatory. Both groups of anti-VEGF substances provide similar rates of vision improvement but with superior anatomic outcomes and fewer injections in the corticosteroid implant-treated eyes. However, more patients receiving the corticosteroid implant lose vision mainly due to cataract [4].
Altogether, the results of this study can not be validated and extrapolated because a stepwise linear regression analysis of the potential predictors of functional outcome was not carried out. Regardless of the anti-VEGF agents employed (bevacizumab/ranibizumab/aflibercept/ corticosteroid), the efficacy of therapy depends primarily on the promptness of the therapy after DME diagnosis [4,5].
References
1. Cicinelli MV, Cavalleri M, Querques L, et al. Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema. Br J Ophthalmol 2017; http:/ dx. doi. org/ 10.1136/bjophthalmol-2017-310242.
2. Freund KB, Korobelnik JF, Devenyi R, et al. Treat-and-extend regimens with anti-VEGF agents in retinal diseases. Retina 2015;35(8):1489-1506.
3. Gover S, Murthy RK, Brar VS, Chalam KV.Normative data for macular thickness by high-definition spectral-domain optical coherence tomography (spectralis). Am J Ophthalmol 2009;148(2):266-271.
4. Calugaru D, Calugaru M. Real-world outcomes of ranibizumab treatment for diabetic macular edema in a United Kingdom National Health Service setting. Am J Ophthalmol 2017;174(2):175-176.
5. Calugaru D, Calugaru M. Comments to: Long-term efficacy and safety of intravitreal dexamethasone implant for the treatment of diabetic macular edema. Eur J Ophthalmol 2016;26(6):171-172.
We warmly thank Calugaru D and associates for their correspondence regarding our article entitled " Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema".1
We agree with them about some of the challenges concerning our study. As we have acknowledged in the limitation section of our article, our study is limited by several biases, as its design was retrospective. In particular, patients selection and follow-up represented some of the major flaws in our study. We collected data about patients switched to dexamethasone for different reasons; some patients were treatment-naïve, other had already undergone treatments for diabetic macular edema (DME). No one disclosed any feature of chronic long-standing DME; all of them received prompt therapy after DME diagnosis.
Some of them showed a good response to ranibizumab loading-dose, with satisfying reduction of macular thickness after the injections. Nevertheless, no patient disclosed a completely dry macula after the anti-vascular endothelial growth factor (VEGF) loading-dose.
As far as it regards the final functional and anatomical gain at the end of the follow-up, the Authors state that the outcomes of this series were unsatisfactory. However, in the non-responders group, despite initial poor results, the best-corrected visual acuity (BCVA) had improved significantly (p<0.05) and clinically (> 5 letters), as highlighted in the...
We warmly thank Calugaru D and associates for their correspondence regarding our article entitled " Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema".1
We agree with them about some of the challenges concerning our study. As we have acknowledged in the limitation section of our article, our study is limited by several biases, as its design was retrospective. In particular, patients selection and follow-up represented some of the major flaws in our study. We collected data about patients switched to dexamethasone for different reasons; some patients were treatment-naïve, other had already undergone treatments for diabetic macular edema (DME). No one disclosed any feature of chronic long-standing DME; all of them received prompt therapy after DME diagnosis.
Some of them showed a good response to ranibizumab loading-dose, with satisfying reduction of macular thickness after the injections. Nevertheless, no patient disclosed a completely dry macula after the anti-vascular endothelial growth factor (VEGF) loading-dose.
As far as it regards the final functional and anatomical gain at the end of the follow-up, the Authors state that the outcomes of this series were unsatisfactory. However, in the non-responders group, despite initial poor results, the best-corrected visual acuity (BCVA) had improved significantly (p<0.05) and clinically (> 5 letters), as highlighted in the text.
The analysis of central macular thickness (CMT) at 12 months on optical coherence tomography disclosed that the poor and good responders reached CMT of 363 microns and of 359 microns, respectively. Despite being more than the cutoff for the upper level of normal CMT, as suggested by the Authors, for DME eyes a CMT of ~350um should be considered as a good outcome, as values inferior to this cut-off would indicate impending atrophy of the neurovascular tissue. As a validation of our approach, we referred to the latest Diabetic Retinopathy Clinical Research Network (DRCR.net) guidelines about persistent macular thickening after ranibizumab treatment, according to which CMT appeared to be a less important prognostic factor in DME outcomes. In fact, persistent macular edema was associated with similar long-term improvement in visual acuity showed by patients in which DME did not persist.2 Finally, we would like to specify that we analyzed data of included patients until 12-months follow-up; these patients did not conclude treatment for DME, and most of them continued to receive injections for their condition.
We perfectly agree that, along with CMT, other OCT biomarkers (as disorganization of the retinal inner layers, integrity of the ellipsoid zone and of the cone outer segment tips, presence of taut internal limiting membrane or epiretinal membrane, and vitreomacular traction) should be analyzed in order to predict the prognostic outcome of diabetic patients.3-4 A specific analysis of these parameters was beyond our purposes, but we will include them in a future more complete stepwise linear regression analysis of the data presented in the present study.
We listed the complications of treatment experienced by patients who underwent dexamethasone (DEX) implant, with particular attention to intraocular pressure increase as well as cataract worsening. These two are well-known side-effects of dexamethasone implant and their rate did not exceed the expectations in our study.5 Despite these complications, intravitreal steroids have shown a good safety profile in long-term prospective studies, especially in those cases when anti-VEGF are contraindicated, or fewer intravitreal injections regimen is required.
In conclusion, we kindly disagree with the conclusion of the Authors and we further demonstrated the usefulness of switching the therapeutic drug in diabetic patients non-responders to anti-VEGF the by replying to this letter.
References:
1. Cicinelli MV, Cavalleri M, Querques L, et al. Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema. Br J Ophthalmol 2017; http:/ dx. doi. org/ 10.1136/bjophthalmol-2017-310242.
2. Bressler SB, Ayala AR, Bressler NM, Melia M, Qin H, Ferris FL 3rd, Flaxel CJ, Friedman SM, Glassman AR, Jampol LM, Rauser ME; Diabetic Retinopathy Clinical Research Network. Persistent Macular Thickening After Ranibizumab Treatment for Diabetic Macular Edema With Vision Impairment. JAMA Ophthalmol. 2016 Mar;134(3):278-85. doi: 10.1001/jamaophthalmol.2015.5346.
3. Sun JK, Lin MM, Lammer J, Prager S, Sarangi R, Silva PS, Aiello LP. Disorganization of the retinal inner layers as a predictor of visual acuity in eyes with center-involved diabetic macular edema. JAMA Ophthalmol. 2014 Nov;132(11):1309-16.
4. Iacono P, Parodi MB, Scaramuzzi M, Bandello F. Morphological and functional changes in recalcitrant diabetic macular oedema after intravitreal dexamethasone implant. Br J Ophthalmol. 2016 Sep 13. pii: bjophthalmol-2016-308726. doi: 10.1136/bjophthalmol-2016-308726.
5. Boyer DS, Yoon YH, Belfort R Jr, et al; Ozurdex MEAD Study Group. Three-year, randomized, sham-controlled trial of dexamethasone intravitreal implant in patients with diabetic macular edema. 2014;121:1904-1914.
We read with great interest the study by Salowi and colleagues,[1] analysing risk factors for posterior capsular rupture (PCR) in over 150,000 cataract operations across Malaysia. Many of the significant risk factors were expected and well-recognised, such as junior surgeon or pseudoexfoliation. An interesting finding was increased PCR in males, with odd ratio 1.11 (95% confidence interval 1.04 to 1.17).
Male gender has been found to be a risk factor for PCR in other large retrospective studies. The Cataract National Dataset of 55,567 cataract operations across 12 National Health Service Trusts in the UK found male gender to have an adjusted odds ratio of 1.28 (95% CI 1.13-1.45).[2] We recently reviewed 62,994 cataract operations performed at Moorfields, showing male gender as a significant risk for PCR, with OR 1.490 (95% CI 1.274–1.741).[3] This risk was similar to junior surgeon (OR 1.483) or prior intravitreal injection (OR 1.664), an increasingly acknowledged predictor of complicated surgery.
The reasons for increased PCR in male patients is unclear. Males are significantly more likely to take tamsulosin, an alpha receptor blocker used in the treatment of benign prostatic hypertrophy. This can lead to poor pupillary dilation and intraoperative floppy iris syndrome (IFIS).[4] Although this can be effectively managed with intracameral phenylephrine, iris hooks or Malyugin ring, it remains a risk factor for PCR. Furthermore, males are more likely to be aff...
We read with great interest the study by Salowi and colleagues,[1] analysing risk factors for posterior capsular rupture (PCR) in over 150,000 cataract operations across Malaysia. Many of the significant risk factors were expected and well-recognised, such as junior surgeon or pseudoexfoliation. An interesting finding was increased PCR in males, with odd ratio 1.11 (95% confidence interval 1.04 to 1.17).
Male gender has been found to be a risk factor for PCR in other large retrospective studies. The Cataract National Dataset of 55,567 cataract operations across 12 National Health Service Trusts in the UK found male gender to have an adjusted odds ratio of 1.28 (95% CI 1.13-1.45).[2] We recently reviewed 62,994 cataract operations performed at Moorfields, showing male gender as a significant risk for PCR, with OR 1.490 (95% CI 1.274–1.741).[3] This risk was similar to junior surgeon (OR 1.483) or prior intravitreal injection (OR 1.664), an increasingly acknowledged predictor of complicated surgery.
The reasons for increased PCR in male patients is unclear. Males are significantly more likely to take tamsulosin, an alpha receptor blocker used in the treatment of benign prostatic hypertrophy. This can lead to poor pupillary dilation and intraoperative floppy iris syndrome (IFIS).[4] Although this can be effectively managed with intracameral phenylephrine, iris hooks or Malyugin ring, it remains a risk factor for PCR. Furthermore, males are more likely to be affected by trauma, and traumatic cataract carries an increased risk of PCR. We would welcome further discussion of this less recognised risk factor for PCR.
References:
1. Salowi MA, Chew FLM, Adnan TH, Ismail M, Goh PP: The Malaysian Cataract Surgery Registry: risk Indicators for posterior capsular rupture. The British journal of ophthalmology 2017.
2. Narendran N, Jaycock P, Johnston RL, Taylor H, Adams M, Tole DM, Asaria RH, Galloway P, Sparrow JM: The Cataract National Dataset electronic multicentre audit of 55,567 operations: risk stratification for posterior capsule rupture and vitreous loss. Eye (London, England) 2009, 23(1):31-37.
3. Shalchi Z, Okada M, Whiting C, Hamilton R: Risk of Posterior Capsule Rupture During Cataract Surgery in Eyes With Previous Intravitreal Injections. American journal of ophthalmology 2017, 177:77-80.
4. Chatziralli IP, Peponis V, Parikakis E, Maniatea A, Patsea E, Mitropoulos P: Risk factors for intraoperative floppy iris syndrome: a prospective study. Eye (London, England) 2016, 30(8):1039-1044.
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, f...
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, for example STROBE for observational studies, CONSORT for randomized trials, and PRISMA for systematic reviews and meta-analyses of intervention studies (see https://www.equator-network.org/reporting-guidelines/ for a full list of reporting standards).
Related to this project, CEV is examining the quality of published systematic review methods and maintains a database of systematic reviews in eyes and vision (http://cmr.cochrane.org/?CRGReportID=11343). We classify systematic reviews as “reliable” based on adherence to pre-specified criteria, (3) and send the “reliable” reviews to the American Academy of Ophthalmology for reference when issuing clinical practice guidelines. (4)
We urge all stakeholders to join our effort to ensure that vision science is recognized as evidence-based.
Literature cited
1. Joksimovic L, Koucheki R, Popovic M, Ahmed Y, Schlenker MB, Ahmed IIK. Risk of bias assessment of randomized controlled trials in high-impact ophthalmology journals and general medical journals: a systematic review. Br J Ophthalmol 2017;0:1–6. doi:10.1136/bjophthalmol-2017-310313
2. Institute of Medicine (IOM). Finding what works in health care: Standards for systematic reviews. Washington, DC: The National Academies Press; 2011
3. Lindsley K, Li T, Ssemanda E, Virgili G, Dickersin K. Interventions for age-related macular degeneration: Are practice guidelines based on systematic reviews? Ophthalmol. 2016;123(4):884-97. doi:10.1016/j.ophtha.2015.12.004.
4. Mayo-Wilson E, Ng SM, Chuck RS, Li T. The quality of systematic reviews about interventions for refractive error can be improved: a review of systematic reviews. BMC Ophthalmol.2017; 17:164 doi:10.1186/s12886-017-0561-9.
We have read with interest the article by Dean et al(1). We completely agree with the premise that the ‘patient voice’ is not being fully utilised in all facets of ophthalmic care, ranging from research to clinical practice. Evidence suggests that rather than being a tokenistic addition, listening to the ‘patient voice’ can provide tangible improvements in cost efficiency and healthcare outcomes(2).
A successful project spearheaded by the European Respiratory Society (ERS) called EMBARC(3) (European Multicentre Bronchiectasis Audit and Research Collaboration) sought to be a patient focused project, despite scarce existing infrastructure for patient involvement(3). In the research sphere of the project, patients were involved in clinical trials and studies. They played key roles in study design, wrote letters to secure financial backing for bronchiectasis-related projects, and were active members of advisory boards and ethical committees. Patients were a valuable asset on guideline panels, providing an alternative insight on the merits and negatives of various interventions, as well as their general acceptability. This initiative is a model example of how patients can influence the path research takes, and provides a tested framework for future ophthalmic research to be highly patient-relevant.
Undoubtedly, there will be barriers to effective patient involvement in medical research and these will require flexible and innovative approaches to be overcome. These...
We have read with interest the article by Dean et al(1). We completely agree with the premise that the ‘patient voice’ is not being fully utilised in all facets of ophthalmic care, ranging from research to clinical practice. Evidence suggests that rather than being a tokenistic addition, listening to the ‘patient voice’ can provide tangible improvements in cost efficiency and healthcare outcomes(2).
A successful project spearheaded by the European Respiratory Society (ERS) called EMBARC(3) (European Multicentre Bronchiectasis Audit and Research Collaboration) sought to be a patient focused project, despite scarce existing infrastructure for patient involvement(3). In the research sphere of the project, patients were involved in clinical trials and studies. They played key roles in study design, wrote letters to secure financial backing for bronchiectasis-related projects, and were active members of advisory boards and ethical committees. Patients were a valuable asset on guideline panels, providing an alternative insight on the merits and negatives of various interventions, as well as their general acceptability. This initiative is a model example of how patients can influence the path research takes, and provides a tested framework for future ophthalmic research to be highly patient-relevant.
Undoubtedly, there will be barriers to effective patient involvement in medical research and these will require flexible and innovative approaches to be overcome. These barriers exist from both a patient’s and clinician’s perspective. The most obvious hurdle is the disparity in subject knowledge between both parties and the potential for patients to feel isolated during discussion. Therefore, it is crucial that patient involvement is designed in a way that recognizes this, and provides adequate support either through training schemes or debriefing with expert members prior to meetings(3). There may be resistance from clinicians concerned that the need to accommodate patient understanding may restrict the scope of discussion. Other patient concerns include time commitment and logistical concerns such as travel reimbursements(3), both of which should be adequately addressed. Additionally, care must be taken when defining the patient recruitment criteria in order to ensure the volunteers are truly representative of the patient population concerned.
Ultimately, we applaud the efforts of this article in highlighting what is currently an inadequately tapped resource in the realm of ophthalmology, and we hope to see the ‘patient voice’ become an intrinsic part of future research.
References
1. Dean, S., Mathers, J., Calvert, M., Kyte, D., Conroy, D., Folkard, A., Southworth, S., Murray, P. and Denniston, A. (2017). "The patient is speaking": discovering the patient voice in ophthalmology. The British Journal of Ophthalmology, [online] 101(6), pp.700-708. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28455280 [Accessed 20 Sep. 2017].
2. Burns, K., Rizvi, L., Charteris, A., Laskey, S., Batty, S., Chokar, K. and Choong, K. (2017). Characterizing Citizens’ Preferences for Engagement in Patient Care and Research in Adult and Pediatric Intensive Care Units. Journal of Intensive Care, [online] Available at: http://journals.sagepub.com/doi/full/10.1177/0885066617729127[Accessed 20 Sep. 2017].
Chalmers, J., Timothy, A., Polverino, E., Almagro, M., Ruddy, T., Powell, P. and Boyd, J. (2017). Patient participation in ERS guidelines and research projects: the EMBARC experience. European Respiratory Journal, [online] 13(3), pp.194-207. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5584721/ - C1[Accessed 20 Sep. 2017].
Kenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the li...
Kenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the literature with regard to how visual acuity relates to increased risk of MVC’s in glaucoma patients,3-5 we suggest that these findings be more clearly emphasized. Furthermore, we would appreciate any commentary from the authors regarding visual acuity as a significant risk parameter for MVCs. Specifically, we are interested to know if further analysis of the data would show a particular threshold for visual acuity to incite a significantly higher risk for simulated collision. Given our role to responsibly report the visual capacity of patients to safely operate a motor vehicle, this information may serve useful to further guide visual acuity parameters for motor vehicle licensing.
Author Affiliations:
1. Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX
2. Michael E. Debakey Veterans Affairs Medical Center, Houston, TX
References:
1. Ramulu PY, West SK, Munoz B, Jampel HD, Friedman DS. Driving cessation and driving limitation in glaucoma: the Salisbury Eye Evaluation Project. Ophthalmology. 2009;116(10):1846-1853.
2. Janz NK, Musch DC, Gillespie BW, Wren PA, Niziol LM, Collaborative Initial Glaucoma Treatment Study I. Evaluating clinical change and visual function concerns in drivers and nondrivers with glaucoma. Invest Ophthalmol Vis Sci. 2009;50(4):1718-1725.
3. Yuki K, Awano-Tanabe S, Ono T, et al. Risk Factors for Motor Vehicle Collisions in Patients with Primary Open-Angle Glaucoma: A Multicenter Prospective Cohort Study. PLoS One. 2016;11(11):e0166943.
4. Gracitelli CP, Tatham AJ, Boer ER, et al. Predicting Risk of Motor Vehicle Collisions in Patients with Glaucoma: A Longitudinal Study. PLoS One. 2015;10(10):e0138288.
5. Kwon M, Huisingh C, Rhodes LA, McGwin G, Jr., Wood JM, Owsley C. Association between Glaucoma and At-fault Motor Vehicle Collision Involvement among Older Drivers: A Population-based Study. Ophthalmology. 2016;123(1):109-116.
We noticed the article entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment" by Mulder and associates with interest.(1)
Several studies have been published concluding that elevated aqueous flare values seem to be associated with increased risk for PVR redetachment.(2-4) Schroeder et al reported that values >15 photon counts per milliseconds (pc/ms) increases the risk for PVR 16-fold.(4) Hoerster et al showed that the odds ratio for PVR development with preoperative flare values >15pc/ms was 30.7 (p=0.0001) with a sensitivity of 80% and specificity of 79%.(3) Conart et al verified these findings (OR 12.3, p<0.0001 for later PVR in flare values >15 pc/ms).(2)
In contrast Mulder et al concluded on their data compilation that laser flare measurements are inaccurate in predicting PVR.(1) Logistic regression analyses showed a significant increase in odds with increasing flare at least for the second centre (1) supporting the notion that high flare measurements herald PVR. However, the large variation precluded sufficient sensitivity and specificity to separate between groups. We assume the reason for the large variation is that high-level outliers were included. For center 2 only the highest and the lowest values were excluded, no information is provided for center 1. Values of 100pc/ms, here up to 312pc/ms, are uncommon for the low-level type of i...
We noticed the article entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment" by Mulder and associates with interest.(1)
Several studies have been published concluding that elevated aqueous flare values seem to be associated with increased risk for PVR redetachment.(2-4) Schroeder et al reported that values >15 photon counts per milliseconds (pc/ms) increases the risk for PVR 16-fold.(4) Hoerster et al showed that the odds ratio for PVR development with preoperative flare values >15pc/ms was 30.7 (p=0.0001) with a sensitivity of 80% and specificity of 79%.(3) Conart et al verified these findings (OR 12.3, p<0.0001 for later PVR in flare values >15 pc/ms).(2)
In contrast Mulder et al concluded on their data compilation that laser flare measurements are inaccurate in predicting PVR.(1) Logistic regression analyses showed a significant increase in odds with increasing flare at least for the second centre (1) supporting the notion that high flare measurements herald PVR. However, the large variation precluded sufficient sensitivity and specificity to separate between groups. We assume the reason for the large variation is that high-level outliers were included. For center 2 only the highest and the lowest values were excluded, no information is provided for center 1. Values of 100pc/ms, here up to 312pc/ms, are uncommon for the low-level type of inflammation in primary rhegmatogenous retinal detachment. Therefore, we challenge laser flare values beyond 100pc/ms. Measurements become easily disturbed by background lighting or cells leading to the necessity to exclude measurements falsified by artefacts.
It would be interesting to know details on the protocol the authors followed to exclude artefacts. Furthermore, we would appreciate an explanation for the unusual variation of the values and the discrepant data towards previous reports.(2,4)
Reference List
1. Mulder VC, Tode J, van Dijk EH, Purtskhvanidze K, Roider J, Van Meurs JC et al. Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Br.J.Ophthalmol 2017. doi: 10.1136/bjophthalmol-2016-309134.
2. Conart JB, Kurun S, Ameloot F, Trechot F, Leroy B, Berrod JP. Validity of aqueous flare measurement in predicting proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Acta Ophthalmol 2016.
3. Hoerster R, Hermann MM, Rosentreter A, Muether PS, Kirchhof B, Fauser S. Profibrotic cytokines in aqueous humour correlate with aqueous flare in patients with rhegmatogenous retinal detachment. Br.J.Ophthalmol 2013;97:450-3.
4. Schroder S, Muether PS, Caramoy A, Hahn M, Abdel-Salam M, Diestelhorst M et al. Anterior chamber aqueous flare is a strong predictor for proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Retina 2012;32:38-42.
Thank you for your interest in our publication entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment".
As per request, we would like to provide more details on our protocol.
As described in our discussion, centre 1 used the mean of ten correct measurements making sure these measurements did not differ more than 2 standard deviations from each other. In centre 2, seven correct measurements were recorded of which the highest and lowest value were discarded leaving an average of five measurements. A correct measurement meant that the background readings did not differ more than 15% (indicated by the code ‘BG’ on the output) and that single “cell/C” measurements were replaced by an additional measurement. In addition, measurements with a small signal to noise ratio (indicated by the code ‘s/n’) were avoided as much as possible. However, with low flare values this was not always feasible. The flare meters were located in a room with blinds (centre 1) and a room without windows (centre 2); computer screens and lights were turned off during measurements. Both flare meters were calibrated monthly to assure correct readings. We therefore believe that the included mean values are artefact free.
Despite the exclusion of patients with additional conditions such as AMD, CRVO and preoperative PVR grade C or higher, we did end up with patients with a preopera...
Thank you for your interest in our publication entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment".
As per request, we would like to provide more details on our protocol.
As described in our discussion, centre 1 used the mean of ten correct measurements making sure these measurements did not differ more than 2 standard deviations from each other. In centre 2, seven correct measurements were recorded of which the highest and lowest value were discarded leaving an average of five measurements. A correct measurement meant that the background readings did not differ more than 15% (indicated by the code ‘BG’ on the output) and that single “cell/C” measurements were replaced by an additional measurement. In addition, measurements with a small signal to noise ratio (indicated by the code ‘s/n’) were avoided as much as possible. However, with low flare values this was not always feasible. The flare meters were located in a room with blinds (centre 1) and a room without windows (centre 2); computer screens and lights were turned off during measurements. Both flare meters were calibrated monthly to assure correct readings. We therefore believe that the included mean values are artefact free.
Despite the exclusion of patients with additional conditions such as AMD, CRVO and preoperative PVR grade C or higher, we did end up with patients with a preoperative flare value above 100 pc/ms. These measurements were accurate because they showed small SD’s (e.g. mean 263.8± SD 2.8; mean 196.5±SD 3.5; mean 162.0±SD 6.0) and flare was also visible upon slit lamp examination. Therefore, because these values do occur in patients with a rhegmatogenous retinal detachment we feel that inclusion of these measurements is mandatory.
However, excluding patients with a preoperative flare value above 100 pc/ms from our regression and ROC analyses – as is suggested by dr. Schaub and colleagues – did not significantly improve the results from either centre 1 or centre 2. Logistic regression centre 1: OR 1.013; p = 0.446, centre 2: OR 1.035; p = 0.028. Sensitivity and specificity at a cut-off of 15 pc/ms dropped to 78 and 39% in centre 1, and 36% and 77% in centre 2 (p = 0.051).
A possible explanation for the discrepancy with the previous reports is our low prevalence of postoperative PVR (7.5% and 6.2% respectively) compared to the previous reports. All previous reports included consecutive patients and found prevalences of 10.3%(1), 14.9%(2) and 20% (3). Both the positive predictive value (PPV) and the odds ratio (OR) are affected by the prevalence. This means that even with comparable sensitivity and specificity the PPV and the OR will be lower when the prevalence is lower. In addition, different reports used different definitions of postoperative PVR. We used reoperation due to epiretinal membranes and/or subretinal strands within six months of initial surgery, as did Schröder et al.(1) Hoerster et al. based their findings on PVR grade C at 3 months postoperatively. While ten patients developed PVR only four (6%) needed a reoperation.(2) It is unclear from the report whether all four patients had a flare value > 15 pc/ms but if this were the case this would give a PPV of 20% and OR of 8 instead of the reported 40% and 30. Conart et al. used PVR grade B and C at 6 months as the outcome. Moreover, they included 20% patients with preoperative PVR grade C which influenced the postoperative number of patients with PVR. Both studies included flare values > 100 pc/ms which confirms that high values are not uncommon.(2,3)
The predictive value of the flare value thus depends on the patient group that is targeted. Our results indicate that there is a large overlap in flare values which makes selecting those patient at high risk for developing postoperative PVR (according to our definition) inaccurate.(4) Dependent on the implications of a positive test result (flare value > 15pc/ms) we should decide whether a false discovery rate of 60-90% is acceptable.
We agree with dr. Schaub and collegues that identifying patients with an increased risk of PVR would be of great benefit in studies of the treatment of PVR by “enriching” the study population. Unfortunately, in our study, we have not been able to validate preoperative flare measurements for this purpose.
Recently, however, we have shown that postoperative flare measurements may have that potential (Mulder et al, non published data, presented at the NOG Maastricht, March 29 2017), and we encourage other groups to validate these findings.
References
1 Schroder S, Muether PS, Caramoy A, et al. Anterior chamber aqueous flare is a strong predictor for proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Retina 2012;32(1):38-42.
2 Hoerster R, Hermann MM, Rosentreter A, et al. Profibrotic cytokines in aqueous humour correlate with aqueous flare in patients with rhegmatogenous retinal detachment. Br.J.Ophthalmol. 2013;97(4):450-453.
3 Conart JB, Kurun S, Ameloot F, et al. Validity of aqueous flare measurement in predicting proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment. Acta Ophthalmol. 2016;.
4 Mulder VC, Kluft C, van Etten PG, et al. Higher vitreous concentrations of dabigatran after repeated oral administration. Acta Ophthalmol. 2017;.
Dear Sir,
We read the article "Classification of diabetic macular odema using ultra-widefield angiography and implications for response to anti-VEGF therapy" by Xue K, et al1 with great interest. The authors aimed to classify Diabetic macular odema [DMO] using ultra-widefield flourescein angiography [UWFA] and evaluate response to anti-vascular endothelial growth factor [anti-VEGF]. They concluded that UWFA facilitates detection of peripheral ishemia. DMO group with significant peripheral ishemia responded well to anti-VEGF therapy than other groups. We congratulate the author for their lightening study about subject and would like to make some contributions about study.
The study did not mention the severity of diabetes of the patients enrolled in the study nor systemic comorbid conditions like glycemic control, systolic hypertension, protinuria1, which would alter the incidence of macular odema.2, 3
The study selected patients with DMO who have been given subthreshold micropulse diode laser. As it was not mentioned in the study, we wonder if the study desires to see the response of anti-VEGF in non-resolving macular odema patients alone. Also, it was to our surprise why patients with Panretinal photocoagulation were not excluded from the study while classifying the patients into 3 groups .
The classification of DMO into three groups was not clearly satisfying because there would be always a component of ishemia overlapping between t...
Dear Sir,
We read the article "Classification of diabetic macular odema using ultra-widefield angiography and implications for response to anti-VEGF therapy" by Xue K, et al1 with great interest. The authors aimed to classify Diabetic macular odema [DMO] using ultra-widefield flourescein angiography [UWFA] and evaluate response to anti-vascular endothelial growth factor [anti-VEGF]. They concluded that UWFA facilitates detection of peripheral ishemia. DMO group with significant peripheral ishemia responded well to anti-VEGF therapy than other groups. We congratulate the author for their lightening study about subject and would like to make some contributions about study.
The study did not mention the severity of diabetes of the patients enrolled in the study nor systemic comorbid conditions like glycemic control, systolic hypertension, protinuria1, which would alter the incidence of macular odema.2, 3
The study selected patients with DMO who have been given subthreshold micropulse diode laser. As it was not mentioned in the study, we wonder if the study desires to see the response of anti-VEGF in non-resolving macular odema patients alone. Also, it was to our surprise why patients with Panretinal photocoagulation were not excluded from the study while classifying the patients into 3 groups .
The classification of DMO into three groups was not clearly satisfying because there would be always a component of ishemia overlapping between the different groups. Third group was basically with neovascularisation according to the author, but ishemia is the basic driving cause for neovascularisation. Also, it was not mentioned about type of neovascularisation that was considered in the third group, Neovascularisation of disc [NVD] OR Neovasculasiation elsewhere [NVE]. Since neovascularisation at disc would suggest that there is global ishemia. So we feel second and third group were not clearly defined by authors in the study.
According to the study, group 2 i.e. with peripheral ishemic group responded better to anti-VEGF than other groups. We wonder how would this grouping alter the management of DMO in any way, as it is already known that DMO treated with anti-VEGF would improve vision and reduce the macular odema.4, 5
Financial Support and Sponsorship
Nil
Conflicts of Interest
There are no conflicts of interest
References:
1. Xue K etal. Classification of diabetic macular odema using ultra-widefield angiography and implications for response to anti-VEGF therapy. Br J Ophthalmol 2017; 101:559-563.
2. Early treatment for diabetic retinopathy study [ETDRS] research group .ETDRS design and baseline patient characteristics. ETDRS report number 7 .Ophthalmology 1991; 98: 741 - 756.
3. Ronald KLIEN, MD, MPH, Michaiel D. Knudston, MS, etal. WISCONSON EPIDEMIOLOGICAL STUDY OF DIABETIC RETINOPATHY, the twenty five year incidence of macular odema in persons with type 1 diabetes .Ophthalmology 2009; 116 [3]: 497-503.
4. Paul Mitchell MD, PhD, Francesco Bandello, MD, FEBO; etal. RESTORE STUDY. Ranibizumab monotherapy or combined with laser versus monotherapy for diabetic macular odema. Ophthalmology 2011; 118 [4]: 615-25.
5. Pascale Massin, MD, PhD, Francesco Bandello ,MD ,FEBO etal Safety and efficacy of Ranibizumab in Diabetic Macular Edema [RESOLVE STUDY]. Diabetes care 2010; 33: 2399-2405.
We read with interest the recently published study by Kim et al, which the authors described as a cross-sectional, observational, case-control study. As a single study such a design is not possible since cross-sectional and case-control studies are two distinct types of study designs. The authors compared the percent with lower lid epiblepharon between those with and without congenital glaucoma and reported that controls were matched on age and date of outpatient visit to the cases, which would suggest this is a matched case-control study. However, the statistical analysis employed did not account for the matched nature of the study design and therefore was not appropriate. Statistical procedures that account for the matched nature of the study should have been employed. The authors are urged to conduct a reanalysis of their study, amending their interpretation as warranted.
Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema
Dan Calugaru, Mihai Calugaru
Department of Ophthalmology, Univ of Medicine Cluj-Napoca/Romania
Re: Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema. Cicinelli et al. Br J Ophthalmol 2017; http: /dx.doi. org/ 10.1136/bjophthalmol-2017-310242.
Dear Editor
Show MoreWe would like to address several challenges that have arisen from the study by Cicinelli et al (1), which can be specifically summarized below.
1. The study was retrospectively conducted, with a selection bias attributable to the heterogeneity of the patients included, for example, six patients were affected by the type 1 diabetes mellitus; eighteen eyes were phakic; twenty seven eyes underwent cataract extraction and intraocular lens implant; and thirteen eyes received grid macular photocoagulation for diabetic macular oedema (DME) prior to ranibizumab (RNB).
2. After undergoing three loading-dose intravitreal injections of RNB performed at fixed 4-week intervals for the first 12 weeks, all the patients regardless of functional and anatomical characteristics, were shifted to dexamethasone implant (DEX implant 0.7 mg; Ozurdex; Allergan, Irvine, California, USA) continued at 4-month intervals until stable best-corrected visual acuity (BCVA) was reached. However, nothing was...
We warmly thank Calugaru D and associates for their correspondence regarding our article entitled " Early response to ranibizumab predictive of functional outcome after dexamethasone for unresponsive diabetic macular oedema".1
Show MoreWe agree with them about some of the challenges concerning our study. As we have acknowledged in the limitation section of our article, our study is limited by several biases, as its design was retrospective. In particular, patients selection and follow-up represented some of the major flaws in our study. We collected data about patients switched to dexamethasone for different reasons; some patients were treatment-naïve, other had already undergone treatments for diabetic macular edema (DME). No one disclosed any feature of chronic long-standing DME; all of them received prompt therapy after DME diagnosis.
Some of them showed a good response to ranibizumab loading-dose, with satisfying reduction of macular thickness after the injections. Nevertheless, no patient disclosed a completely dry macula after the anti-vascular endothelial growth factor (VEGF) loading-dose.
As far as it regards the final functional and anatomical gain at the end of the follow-up, the Authors state that the outcomes of this series were unsatisfactory. However, in the non-responders group, despite initial poor results, the best-corrected visual acuity (BCVA) had improved significantly (p<0.05) and clinically (> 5 letters), as highlighted in the...
We read with great interest the study by Salowi and colleagues,[1] analysing risk factors for posterior capsular rupture (PCR) in over 150,000 cataract operations across Malaysia. Many of the significant risk factors were expected and well-recognised, such as junior surgeon or pseudoexfoliation. An interesting finding was increased PCR in males, with odd ratio 1.11 (95% confidence interval 1.04 to 1.17).
Male gender has been found to be a risk factor for PCR in other large retrospective studies. The Cataract National Dataset of 55,567 cataract operations across 12 National Health Service Trusts in the UK found male gender to have an adjusted odds ratio of 1.28 (95% CI 1.13-1.45).[2] We recently reviewed 62,994 cataract operations performed at Moorfields, showing male gender as a significant risk for PCR, with OR 1.490 (95% CI 1.274–1.741).[3] This risk was similar to junior surgeon (OR 1.483) or prior intravitreal injection (OR 1.664), an increasingly acknowledged predictor of complicated surgery.
The reasons for increased PCR in male patients is unclear. Males are significantly more likely to take tamsulosin, an alpha receptor blocker used in the treatment of benign prostatic hypertrophy. This can lead to poor pupillary dilation and intraoperative floppy iris syndrome (IFIS).[4] Although this can be effectively managed with intracameral phenylephrine, iris hooks or Malyugin ring, it remains a risk factor for PCR. Furthermore, males are more likely to be aff...
Show MoreDear Editors,
We are writing to express concerns about an article published recently in BJO. (1) While Joksimovic and colleagues claim to have conducted a systematic review, they did not. Rather, they describe a cross-sectional study of randomized trials in ophthalmology with two comparison (or “exposure”) groups: trials published in ophthalmology journals, and trials published in general medical journals. In contrast, a systematic review (also a cross sectional study) has been defined as "… a scientific investigation that focuses on a specific question and uses explicit, prespecified scientific methods to identify, select, assess, and summarize the findings of similar but separate studies." (2)
To minimize mislabeling of systematic reviews, among other purposes, Cochrane Eyes and Vision (CEV) is partnering with individual ophthalmology and optometry journals to appoint a knowledgeable associate editor responsible for editorial functions related to systematic reviews at each journal (http://eyes.cochrane.org/associate-editors-eyes-and-vision-journals). Our research has indicated that many published eye and vision articles billed as “systematic reviews” do not adhere to accepted criteria, and are not reliable. (3)
In addition to adding associate editors for systematic reviews to their team, journal editors can insist that authors adhere to reporting standards, f...
Show MoreWe have read with interest the article by Dean et al(1). We completely agree with the premise that the ‘patient voice’ is not being fully utilised in all facets of ophthalmic care, ranging from research to clinical practice. Evidence suggests that rather than being a tokenistic addition, listening to the ‘patient voice’ can provide tangible improvements in cost efficiency and healthcare outcomes(2).
A successful project spearheaded by the European Respiratory Society (ERS) called EMBARC(3) (European Multicentre Bronchiectasis Audit and Research Collaboration) sought to be a patient focused project, despite scarce existing infrastructure for patient involvement(3). In the research sphere of the project, patients were involved in clinical trials and studies. They played key roles in study design, wrote letters to secure financial backing for bronchiectasis-related projects, and were active members of advisory boards and ethical committees. Patients were a valuable asset on guideline panels, providing an alternative insight on the merits and negatives of various interventions, as well as their general acceptability. This initiative is a model example of how patients can influence the path research takes, and provides a tested framework for future ophthalmic research to be highly patient-relevant.
Undoubtedly, there will be barriers to effective patient involvement in medical research and these will require flexible and innovative approaches to be overcome. These...
Show MoreKenzo J. Koike, MD1; Lauren S. Blieden, MD1,2; Yvonne I. Chu, MD1; Silvia Orengo-Nania, MD1,2; Kristin S. Biggerstaff, MD2; Bac T. Nguyen, MD1; Peter T. Chang, MD1,2; Benjamin J. Frankfort, MD, PhD1
Assessing the visual standards to safely operate a motor vehicle is a challenging topic and discussion that we regularly encounter in our glaucoma population. Multi-centered and population-based studies previously have shown that patients with glaucoma are at particularly increased driving risk, due to their visual deficits.1,2 As such, we greatly appreciate the contributions from Kunimatsu-Sanuki and colleagues, who evaluated patients with advanced glaucoma, and how they performed with a driving simulator. As part of their analysis, the authors focused on specific visual sub-fields, and how those may correlate with the incidence of motor vehicle collisions (MVCs). Their conclusions noted that inferior visual field deficits, age, and visual acuity, were significant factors that contributed to the rate of MVCs. However, we noticed that visual acuity of the better eye (recorded as logMAR) was a significantly higher risk factor (odds ratio of 28.59 and 75.71 for analyses 1 and 2, respectively, as shown in Table 3) for collisions during simulated driving. With such a dramatically higher risk of simulated collision based on visual acuity, it is likely that this parameter alone is the most significant factor to influence the risk of MVCs. As there is some discrepancy in the li...
Show MoreWe noticed the article entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment" by Mulder and associates with interest.(1)
Several studies have been published concluding that elevated aqueous flare values seem to be associated with increased risk for PVR redetachment.(2-4) Schroeder et al reported that values >15 photon counts per milliseconds (pc/ms) increases the risk for PVR 16-fold.(4) Hoerster et al showed that the odds ratio for PVR development with preoperative flare values >15pc/ms was 30.7 (p=0.0001) with a sensitivity of 80% and specificity of 79%.(3) Conart et al verified these findings (OR 12.3, p<0.0001 for later PVR in flare values >15 pc/ms).(2)
In contrast Mulder et al concluded on their data compilation that laser flare measurements are inaccurate in predicting PVR.(1) Logistic regression analyses showed a significant increase in odds with increasing flare at least for the second centre (1) supporting the notion that high flare measurements herald PVR. However, the large variation precluded sufficient sensitivity and specificity to separate between groups. We assume the reason for the large variation is that high-level outliers were included. For center 2 only the highest and the lowest values were excluded, no information is provided for center 1. Values of 100pc/ms, here up to 312pc/ms, are uncommon for the low-level type of i...
Show MoreThank you for your interest in our publication entitled "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment".
As per request, we would like to provide more details on our protocol.
As described in our discussion, centre 1 used the mean of ten correct measurements making sure these measurements did not differ more than 2 standard deviations from each other. In centre 2, seven correct measurements were recorded of which the highest and lowest value were discarded leaving an average of five measurements. A correct measurement meant that the background readings did not differ more than 15% (indicated by the code ‘BG’ on the output) and that single “cell/C” measurements were replaced by an additional measurement. In addition, measurements with a small signal to noise ratio (indicated by the code ‘s/n’) were avoided as much as possible. However, with low flare values this was not always feasible. The flare meters were located in a room with blinds (centre 1) and a room without windows (centre 2); computer screens and lights were turned off during measurements. Both flare meters were calibrated monthly to assure correct readings. We therefore believe that the included mean values are artefact free.
Despite the exclusion of patients with additional conditions such as AMD, CRVO and preoperative PVR grade C or higher, we did end up with patients with a preopera...
Show MoreDear Sir,
Show MoreWe read the article "Classification of diabetic macular odema using ultra-widefield angiography and implications for response to anti-VEGF therapy" by Xue K, et al1 with great interest. The authors aimed to classify Diabetic macular odema [DMO] using ultra-widefield flourescein angiography [UWFA] and evaluate response to anti-vascular endothelial growth factor [anti-VEGF]. They concluded that UWFA facilitates detection of peripheral ishemia. DMO group with significant peripheral ishemia responded well to anti-VEGF therapy than other groups. We congratulate the author for their lightening study about subject and would like to make some contributions about study.
The study did not mention the severity of diabetes of the patients enrolled in the study nor systemic comorbid conditions like glycemic control, systolic hypertension, protinuria1, which would alter the incidence of macular odema.2, 3
The study selected patients with DMO who have been given subthreshold micropulse diode laser. As it was not mentioned in the study, we wonder if the study desires to see the response of anti-VEGF in non-resolving macular odema patients alone. Also, it was to our surprise why patients with Panretinal photocoagulation were not excluded from the study while classifying the patients into 3 groups .
The classification of DMO into three groups was not clearly satisfying because there would be always a component of ishemia overlapping between t...
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