715 e-Letters

  • Letter to the Editor: Non-invasive intracranial pressure estimation using ultrasonographic measurement of area of optic nerve subarachnoid space

    Dear Editor:

    We read the paper on non-invasive intracranial pressure determination by Zhang et al(1) with great interest and hope. We fully agree that the search for non-invasive intracranial pressure (ICP) evaluations is of high importance and should be continued. The Bland-Altman plot showing the difference between predicted and intracranially measured pressure looks very impressive. There are, however, still a few points and limits we would like to address concerning the anatomy of the optic nerve, the optic canal, and the basic concept the authors used.

    Cerebrospinal fluid (CSF) from the intracranial subarachnoid spaces and the subarachnoid space of the optic nerve (SAS -ON) communicate via the optic canal. Using three-dimensional reconstruction of the optic canal in normal tension glaucoma (NTG) patients, this was found to be narrower than in an age-related cohort of normals,(2) thus questioning the patency of the CSF pathway between the pituitary cistern and the SAS-ON. Further, optic canal dimensions in a normal population are quite variable amongst individuals, and even between orbits within the same individual.(3) These facts largely influence the results the authors present. Further, studies in patients with NTG and patients with elevated ICP (such as patients with idiopathic intracranial hypertension) were shown to have developed an optic nerve sheath compartment syndrome. In such cases, the CSF dynamics between the intracranial CSF and the CSF in...

    Show More
  • Quality of the coding and data on AMD

    We read with great interest the article of Gokhale et al [1] on their retrospective study of metformin use and risk of age-related macular degeneration (AMD) in individuals with type 2 diabetes mellitus (T2DM). In this study Gokhale and colleagues used data derived from IQVIA Medical Research Data (IMRD-UK), formerly known as The Health Improvement Network (THIN), and found no change in AMD risk in those taking metformin.

    An issue with this study is the quality of the GP coding and data on AMD. The authors cite a validation study of THIN data [2] but this study only validated cases identified as having AMD. There was no validation of the quality of data on the absence of AMD. So, the confirmation of positives was high (confirmed AMD cases quoted as 97%) but the false negative rate, is unknown. Also, the validation was by an ophthalmologist reviewing all the GP data, not using recognised diagnostic criteria or a grading scheme for AMD. Furthermore, the authors included a code for “drusen” into their AMD group which was not a code included in the validation study by Vassilev et al [2]. It is likely that this code includes patients with common physiological drusen and not an AMD diagnosis.

    We have previously performed a systematic review and meta-analysis [3] of five studies [4–8] on the relationship between metformin use and AMD, which we have now updated to include Gokhale et al [1] and Jiang et al [9]. Including their data, we found a beneficial odds ratio of...

    Show More
  • RE: Association of lipid-lowering drugs and antidiabetic drugs with age-related macular degeneration: a meta-analysis in Europeans

    Mauschitz et al. (1) conducted a meta-analysis to investigate the association of systemic medications with age-related macular degeneration (AMD) in the general population. A pooled odds ratios (95% confidence intervals [CIs]) of lipid-lowering drugs (LLD) and antidiabetic drugs for any AMD were 0.85 (0.79 to 0.91) and 0.78 (0.66 to 0.91), respectively. In contrast, late AMD was not significantly associated with systemic medications. There is an information that antidiabetics, lipid-lowering agents, and antioxidants could theoretically be repurposed for AMD treatment (2). I present information regarding the effect of antidiabetic medications on the risk of AMD.

    Blitzer et al. (3) conducted a case-control study and metformin use was significantly associated with reduced odds of AMD, presenting dose dependent manner. But metformin did not have an effect of protecting diabetic retinopathy. In contrast, Gokhale et al. (4) conducted a retrospective cohort study to evaluate the effect of metformin on the risk reduction of AMD. The adjusted hazard ratio (95% CI) of patients prescribed metformin (with or without other antidiabetic medications) against those prescribed any other antidiabetic medication only for AMD was 1.02 (0.92 to 1.12). Vergroesen et al. (5) conducted a cohort study and a lower risk of AMD was not observed in patients with metformin, but other diabetes medication was significantly associated with a lower risk of AMD.

    Anyway, clinical trials are nee...

    Show More
  • Mr

    The paper advises that the population inspected was predominately of white background and is looking to find ways of expanding its knowledge of non-white ethnicity within the sphere of retina testing. Within the following paper : Ethnicity and Type 2 diabetes in the UK by
    L. M. Goff; it states that the prevalence of Type 2 diabetes within the non-white community is particularly high. a quote from this paper:
    "Among minority ethnic communities, the prevalence is alarmingly high, approximately three to five times higher than in the white British population. "
    Which brings me to my response: All UK Type 2 diabetics are offered eye screening during which the retina is photographed every year. These digital photographs are examined by medical staff looking for vein bleeding and are held by the NHS. Given the hign incidence of Type 2 diabetes in non-white citizens a very large number of these records will be available and so allow a useful extension to the work done by Professor Rudnicka.

  • The role of keratometry in myopia control practice.

    It is generally believed that retinal neurons stop growing in number after birth in humans.1, 2 But recent research has shown retinal neurogenesis in neonatal 1-3 month old monkeys.3 This poses the question of how the sclera and the retina grow during emmetropization. The ora serrata is reported to be 2 mm wide growing to 6-7mm (approximately 5mm difference) in adult life as the scleral tunic grows more than the retina.4 The vitreous chamber depth in newborns is 10.6mm long and also grows roughly by 6 mm to an adult axial value of 17mm on average.5 It is then possible that during the first 3 months of human life, at that rapid growth phase from 17mm to 19mm in mean axial length,6 the retina could grow at least 1mm to compensate in part for that rapid elongation. The eyes of males and females have only a 0.1mm difference at birth with very small differences in body length and head circumference, but bigger born babies have longer eyes with less powerful corneas,7 so a bigger born girl may have a bigger eye with flatter cornea than a smaller born male. When adulthood is reached, women have eyes shorter than those of men by 0.7mm, with steeper corneas and more powerful crystalline lenses.8 As the cornea stabilizes by ages 2-3 in infants, these differential growth patterns are probably established early in life.4 And as usually happens not only among males and females, emmetropic or low hyperopic eyes that develop low corneal powers are longer than eyes that stay with steep co...

    Show More
  • Real-world data may answer questions which randomized clinical trial cannot in retinal surgery

    Randomized controlled trials (RCTs) are considered to be the best method for evaluating the effectiveness of medical interventions.1 Despite their strengths, RCTs have substantial limitations.1 Although RCTs have strong internal validity, they occasionally lack external validity and generalizations of findings outside the study population may be invalid. More specifically in retinal surgery, there are many obstacles to conducting RCTs to address the specific questions asked, so the analysis using real-world data is useful.2 Drs Anguita and Charteris wrote an editorial in the British Journal of Ophthalmology (BJO) on the merits and limitations of studies using real-world data.3 They cited our papers that were recently published in BJO which used the data collected in the Japan Retinal Detachment Registry (J-RD registry), and I would like to comment on with a focus on the retinal surgery.4,5

    As correctly stated by Drs Anguita and Charteris, studies using the propensity score matching method cannot be performed well if one is not familiar with the limitations of this technique. 3 However, this is also true for those who do not have a deep understanding of the disease and may make incorrect interpretations. This would be the case for our paper4 cited in the editorial. This study compared pars plana vitrectomy (PPV) and scleral buckling for superior RD without macula detachment using the data from the J-RD registry. The results which were analyzed using propensity score...

    Show More
  • Increased incidence of endophthalmitis after vitrectomy relative to face mask wearing during COVID-19 pandemic

    Dear Editor.

    We read with interest the manuscript published by Sakamoto et al, on behalf of the Japanese Retina and Vitreous Society, titled: Increased incidence of endophthalmitis after vitrectomy relative to face mask-wearing during COVID-19 pandemic”.[1] In this manuscript, the authors discuss their results after comparing the total prevalence of infectious endophthalmitis among patients that underwent ocular surgery, before and after the peak of the SARS-CoV-2 pandemic in Japan.[1] The authors should be commended due to the level of complexity and significant effort needed to coordinate several centers simultaneously, as well as the detailed description provided in the manuscript regarding the clinical presentation, microbiological results, and outcomes of all cases. Interestingly and despite the low rate of positive vitreous cultures, the authors were able to isolate oral bacteria among several of the cases that developed endophthalmitis during the pandemic, including one caused by Staphylococcus lugdunensis; a pathogen typically hard to eliminate with mechanical washing bacteria, because it accumulates behind the auricle.[1] With all this evidence, the authors provided a compelling argument regarding the inappropriate wearing of face masks could increase the risk of postoperative endophthalmitis. Nevertheless, we believe that there are a few important considerations that the authors may need to address before making such an assumption.
    As a start, we ca...

    Show More
  • Clinical features of chalazion following COVID-19 vaccination

    Clinical features of chalazion following COVID-19 vaccination

    Yusuke Kameda, Megumi Sugai, Karin Ishinabe, Nichika Fukuoka
    Yotsuya-sanchome Ekimae Eye Clinic, Tokyo, Japan

    *Corresponding author: Yusuke Kameda, MD, Yotsuya-sanchome Ekimae Eye Clinic, Tokyo, Japan, 3-7-24 Yotsuya, Shinjuku-ku Tokyo 160-0004, Japan.
    Phone: 81-3-6380-4101; Fax: 81-3-6380-4133; E-mail: y09025618059@leaf.ocn.ne.jp

    To the editor
    We read the article published by Patel et al. with considerable interest [1]. The authors have provided interestingly novel insights into the prevalence and risk factors for chalazion. In their large case-control study comprising 3,453,944 older veteran participants with/without chalazion, the risk factors for chalazion included smoking, conditions of the tear film, conjunctivitis, dry eye, conditions affecting periocular skin, rosacea, allergic conditions, and systemic disorders, such as anxiety. Considering the relationship between chalazion and anxiety, a similar trend as reported in the previous study by Nemet et al. was observed [2]. Moreover, anxiety is generally considered as a psychological reaction to stress [3, 4]. Alsammahi et al. reported that stress is associated with the development of chalazion [5]. In real-world settings, we realize that patients with the onset of chalazion are likely to have anxiety or stress (such as work and examination).
    Incidentally, in the c...

    Show More
  • Comments on Outcome of trabeculectomy versus Ahmed glaucoma valve implantation in the surgical management of glaucoma in patients with Sturge–Weber syndrome

    We read with interest the article by Sarker et al(1) in which they compared the outcomes of trabeculectomy versus Ahmed glaucoma valve (AGV) implantation in Sturge–Weber syndrome (SWS) patients with secondary glaucoma aged 11-62 years. As it noted in the paper, the authors found that complete success rates after 24 months were 80% and 70% in the AGV and trabeculectomy groups, respectively, and qualified success rates were 90% and 85% at same period in the AGV and trabeculectomy groups, respectively. We were delighted to get the conclusion that both AGV implant and trabeculectomy appeared to be safe and efficacious in controlling glaucoma secondary to SWS.
    As it reported by Mohamed et al., the complete success rate and qualified success rate (intraocular pressure≤17mmHg) of trabeculectomy reported were 80% and 100% at 12 postoperative follow-up month, respectively(2). However, the qualified success rate (90%) of AGV implantation in SWS patients with secondary glaucoma is higher than that reported by Hamush et al. (79%)(3) and Kaushik et al. (76%)(4) at 2 years of follow-up. Meanwhile, the trabeculectomy with MMC success rate in this study was comparable to other studies about primary glaucoma(5, 6), but the success rate of tube shunt surgery was higher than in prior reports. The qualified success rate of Baerveldt implantation for patients who not had undergone previous incisional ocular surgery was 73% in Primary Tube Versus Trabeculectomy (PTVT) study(6) and 75% rep...

    Show More
  • Management of Glaucoma During Pregnancy

    Title: Management of Glaucoma During Pregnancy

    Author: Angelo P. Tanna

    Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
    Division of Ophthalmology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois, USA

    Conflicts of Interest Disclosure:
    APT: Consultant to Ivantis, Sandoz, and Zeiss

    APT is supported by an unrestricted departmental grant from Research to Prevent Blindness, NY, NY

    Corresponding Author:
    Angelo P. Tanna, M.D.
    Department of Ophthalmology
    Northwestern University Feinberg School of Medicine
    645 N. Michigan Ave., Suite 440
    Chicago, IL 60611
    Telephone: 312-908-8152
    Fax: 312-503-8152
    E-mail: atanna@northwestern.edu

    Dear Editor:

    I read with interest the work of Doctor Hashimoto and colleagues on the risk of adverse neonatal outcomes (congenital anomalies, preterm birth, low birth weight) associated with maternal exposure to intraocular pressure-lowering medications during pregnancy.1 They used a large Japanese claims database and state-of-the-art statistical methodology to evaluate the frequency of adverse events in a cohort of live births of 91 women who had “at least one dispensation of IOP-lowering medications during the first trimester,” compared to that observed in 735 women with glaucoma or...

    Show More