608 e-Letters

  • 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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  • LETTER TO EDITOR-Treatment patterns and medication adherence of patients with glaucoma in South Korea

    Dear sir/maam

    I whole heartedly appreciate the work conducted by Chan Yun Kim et al in studying the treatment patterns and medication adherence of patients with glaucoma in South Korea.This study concluded that medication non adherence was seen more commonly in males , increased daily number of administration and increase in the number of eyedrops. We have also conducted a similar study at our centre in North India and would like to share our results .Our results are in agreement to the work conducted by Chan Yun Kim stating that increased number of instillation and increased number of eyedrops contribute significantly to medication non adherence. However, in our study we also found that medication adherence varies in different severity grades of glaucoma with severe stages being significantly more adherent than mild to moderate stages of glaucoma.Additionally, there was no difference found in medication adherence among males or females.

    We again express our gratitude to the researcher in enlightening our minds regarding medication adherence in South Korean population.

  • Response: Non-traumatic corneal perforations: aetiology, treatment and outcomes

    Dear editor.

    We thank Sarmad et al. for their interest in our publication. Our study is a retrospective review of several variables regarding non-traumatic corneal perforations (1). In handling clinical records for a retrospective analysis, missing variables represent a common problem. In relation to the location of corneal perforation, information was not available in 25 eyes thus the number does not match. Hence, in consideration of this inevitable flaw we decided not to include the anatomical location of perforation into the model presented in the manuscript, therefore all the variables included in this statistical model had no missing values.

    Clinical treatment of corneal perforation is often complex and a single intervention may not address the patient full pathology, therefore more than one treatment is frequently used. (2) This explains the increased number of initial treatments in the first clinical intervention, one example of this scenario are the patients needing simultaneous tectonic penetrating keratoplasty to restore ocular integrity and concurrent amniotic membrane transplantation to aid in the control of ocular surface. (2)(3)

    These two situations might not be precise in our manuscript, but we take the opportunity of this letter to clarify them. However, that is unquestionably far from compromising the validity of the conclusions. Definitely, as any retrospective study, and as we mention in the discussion of our article, there are li...

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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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  • Re: Non-traumatic corneal perforations: aetiology, treatment and outcomes

    Dear Editor,
    We read your article titled- Non-traumatic corneal perforations: aetiology, treatment and outcomes: with great interest. Corneal perforation is an acute ophthalmic emergency. This review describes the aetiology, plausible location and the multiple ways to approach the management of this condition in a very a systematic manner.
    We do appreciate the organised mode of stratification and care of non- traumatic corneal perforation presented in the article. However, although the results are interesting, we feel that caution should be exercised when drawing conclusions from this data.
    Initially, in results there are 127 eyes of 116 patients under the review. However, while describing the anatomical location of the perforation, only 102 eyes have been accounted for, with no records for the remaining 25 eyes. This would change the calculated p value significantly.
    Similarly, where the initial treatments for perforations were being reviewed 133 eyes were mentioned as treated, thus including six extra unaccounted for eyes to the total. This would seriously jeopardise the authenticity of the calculated results.

    Hence, there appears to be serious doubts regarding the validity of the conclusions of this review. A clearer and more detailed explanation or a recalculation of the results is warranted in this regard.

  • Response to: Response to "Preoperative aqueous humour flare values do not predict proliferative vitreoretinopathy in patients with rhegmatogenous retinal detachment"

    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...

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  • Eye health system strengthening to improve health outcomes in the Caribbean

    I read with interest the article by Pawiroredjo et al1 which described an intervention programme to increase the cataract surgical rate in Suriname. I commend the team at the Suriname Eye Centre (SEC) for their efforts towards eliminating avoidable cataract blindness and visual impairment. The Suriname Rapid Assessment of Avoidable Blindness (2013-2014) survey showed that the proportion of eyes with a postoperative visual acuity <6/60 (poor outcome) was lowest in eyes operated at the SEC (8.5%), higher for the Cuban Mission Milagros (18.8%) and highest in surgeries performed by foreign humanitarian ophthalmic missions (33.3%).

    In neighbouring Trinidad and Tobago, Persad and Bhola reported higher complication rates following cataract surgery performed by a foreign visiting team over a 2-week period compared to those done by local surgeons2. Despite a similar case mix, the visiting team had a sixfold higher vitreous loss rate and a fourfold higher overall surgical complication rate. The authors recommended careful screening of visiting surgical teams by relevant authorities. This supports Pawiroredjo’s suggestion of lowering complication rates and improving outcomes by regulating and limiting access of less experienced foreign ophthalmic teams to eye camps, where 50% of poor outcome was caused by intraoperative complications.

    Suriname has achieved cataract surgical coverage (for all VA levels) of 90% in bilaterally blind or visually impaired individuals age...

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  • 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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  • Obstructive sleep apnoea, primary open angle glaucoma and age-related macular degeneration

    We thank the authors[1] but wish to clarify several points. Stating that ‘glaucoma diagnosis is more common in OSA populations’ is controversial. Glaucoma diagnosis was not more common in our study (RR 1.01, CI 0.85-1.19), which censored prospectively from time of OSA coding throughout England from 1999-2011[2]. This is the largest and longest individual study conducted in this area. Several previous studies also observed no association.

    The authors recommend accounting for ‘risk-associated conditions’. Accounting for potential confounders is important in evaluation of positive associations but less relevant in their absence. We agree that studies in different populations would be useful, particularly in Asia where OAG may differ.

    In recommending a prospective RCT assessing ‘IOP/visual field progression before and after CPAP’, the authors are asking a different question. We have previously advocated this: ‘even in the absence of a positive association, it might still be relevant to identify those patients with genuine co-existence of OSA and POAG, particularly if evidence were to emerge … that OSA treatment could reduce glaucomatous progression’[2].

    Our study never aimed to measure OSA point prevalence, so it is inappropriate to compare a speculative ‘base rate of 2.5%’ with prevalence estimates from a different continent/age-group. Moreover, our OSA cohort represented more severe disease; this should have exaggerated rather than ‘blurred’ any potentia...

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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.