eLetters

577 e-Letters

published between 2014 and 2017

  • Reply to Aptel et al.: Management of postoperative inflammation after cataract and complex ocular surgeries: a systematic review and Delphi survey

    Aptel et al. [1] presented the prevention and management of postoperative ocular inflammation after cataract surgery based on randomised controlled trials, while after trabeculectomy, vitrectomy and combined phacovitrectomy in a two-round Delphi survey.

    The Delphi survey is a technique applied mainly to develop healthcare quality indicators. [2] In this study not only was it applied to evaluate practice patterns among ophthalmologists, but to obtain information on inflammatory potential of a surgical procedure that can be assessed by objective methods.

    It should be underlined that even within the formerly mentioned indications there is little recommendation among researchers to use the Delphi method. [2] The use and reporting of the method needs to be improved, while a panel composition of experts in one field significantly influences ratings. [2,3] Several issues regarding the selection of the panel members is critical if the group consensus technique is to work properly. Two hundred and twenty surgeons from Europe (35%) and the USA (59%) were invited to participate in this Delphi survey. The response rate among the invited experts should be thoroughly explained, as finally 82% of the participating experts were from Europe and the balance was from the USA. This discrepancy might have a high risk of bias and should be thoroughly discussed. Of record, in the United States retinal surgeons do not routinely perform cataract surgery, thus including them in the e...

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  • Reply

    We read with interest the insightful comments in the e-letter submitted by Dr. Gain, Dr. He, Dr. Garcin, and Dr. Thuret on our recently published article.1 As stated in their letter, they previously reported that by using a similar triple staining (i.e., Hoechst 33342, ethidium homodimere and calcein-AM) on the endothelium of whole donor corneas stored in long-term organ culture, the endothelial cell (EC) density in the whole pool of viable ECs in the cornea is routinely, and quite substantially, overestimated.2,3 We completely agree with the authors regarding the importance of assessing the whole pool of viable ECs in corneal grafts.

    We first reported at the 2009 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) that triple-staining a donor graft with propidium iodide, calcein-AM, and Hoechst 33342 allowed for a distinct discrimination between living cells and dead cells. In that report, we hypothesized that the existence of dead cells on the endothelium of the donor cornea suggests an association with the rapid loss of corneal ECs, at least at the early phase, post keratoplasty. However, Gauthier and associates reported3 that there was no difference between the density of viable ECs at day 0 and at day 5 postoperative, thus suggesting that very early EC loss in the host recipient is almost negligible. However, similar to Gain and associates, we believed that it was quite important to measure viable ECD, not to calculate just ECD by...

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  • Incorrect study design and statistical analysis

    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

    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...

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  • Reply

    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...

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  • eletter

    We noticed the article entitled “The existence of dead cells in donor corneal endothelium preserved with storage media” by Kitazawa with interest (Br J Ophthalmol 2017. Oct 5).
    Authors clearly demonstrated, using a triple staining with Hoechst, Propidium Iodide and Calcein-AM, that corneas stored at 4°C in Optisol-GS for 3 to 7 days, the technic most used worldwide, bear a significant number of dead endothelial cells (ECs). They underlined that these non-viable ECs are not recognized by specular cell count done by the eye bank and that this could explain the “cell loss” inevitably noticed post graft. Our team applied, for the first time in 2011 [1] and again in 2016 [2], a similar triple staining on the endothelium of whole corneas stored in long-term organ culture at 31°C, the dominant technic in Europe. We made the same findings as Kitazawa et al. and defined the notion of viable ECD (vECD) as the number of viable ECs per surface unit. Areas without ECs (especially in Descemetic folds), dead and dying EC (that will not survive the storage) clearly explain the important discrepancy between the cell count done by the eye bank (unable to spot them) and the very early postoperative ECD. Our team also demonstrated long ago that vital Trypan blue staining used by certain eye bank is unable to spot all dying cells because its time window of positivity is very narrow, corresponding only to ECs near to desquamate [3]. Viable ECD determined by triple staining therefore appea...

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  • Higher posterior capsular rupture rates in male patients

    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...

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  • Building a reliable evidence base in eyes and vision

    Dear 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...

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  • Comment: “The patient is speaking”: discovering the patient voice in ophthalmology

    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...

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  • Comment on “The role of specific visual subfields in collisions with oncoming cars during simulated driving in patients with advanced glaucoma”

    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...

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