721 e-Letters

• Calculation errors overemphasise the value of increasing visual field test frequency.

Chauhan and co-workers [1] have provided Table 1, showing times taken to detect significant field progression with 80% power, based on a number of modelling parameters: frequency of examinations, rate of field progression, intrasession variability of field assessment. They have also provided Table 2 showing the number of annual eye examinations required to detect different total visual field changes, for different time periods, and for moderate variability. I have checked the calculations of Chauhan and co-workers, using Monte Carlo modelling, assuming a one-tailed significance value of 0.025. Of the 36 outcome values in Table 1, 33 are incorrect. Of the 12 outcome values in Table 2, 11 are incorrect.

Chauhan and co-workers have made 2 main errors in their calculations for Table 1. The first is in applying their estimates of power. The curves shown in Figure 2 (statistical power plotted against number of field examinations) are appropriate for the case of 2 field examinations per year, but Chauhan and co-workers appear to have incorrectly also used them for the cases of 1 examination per year and 3 examinations per year. Separate sets of curves should have been calculated for those conditions. The effect on Table 1 is that the time taken to detect a field change is incorrectly reported as being inversely proportional to the number of examinations per year. This anomalous relationship was commented on by Albert Alm in his 2008 Rapid Response, “Is a field every 4...

• RE: Associations of ophthalmic and systemic conditions with incident dementia in the UK Biobank

Shang et al. conducted a prospective study to examine the effect of ophthalmic and systemic conditions on incident dementia (1). The adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) of age-related macular degeneration (AMD), cataract, diabetes-related eye disease (DRED), and glaucoma at baseline for incident dementia were 1.26 (1.05 to 1.52), 1.11 (1.00 to 1.24), 1.61 (1.30 to 2.00), and 1.07 (0.92 to 1.25), respectively. Diabetes, heart disease, stroke and depression at baseline were also significantly associated with an increased risk of dementia. In addition, some combinations of ophthalmic and systemic conditions were at the higher risk for incident dementia. I have a comment about the study.

Vision impairment is a risk factor of dementia, and poor vision is independently associated with a decline in cognitive function (2). Shang et al. clarified that AMD, cataract, and DRED were risk of incident dementia, and some combinations with systemic conditions accelerated risk of incident dementia. Although glaucoma was not significantly associated with increased risk of al-cause dementia, it was significantly associated with increased risk of vascular dementia. The authors also conducted analysis by excluding data in the first 5 years of follow-up, consistent results were also specified on the combined effects of ophthalmic and systemic conditions on incident dementia. Although the mechanism of increased risk of dementia in combinations with ophthalmic and...

• Change in the ophthalmoscopical optic disc size and shape in a 10-year follow-up: a short comment

I read with interest the article by Jonas et al 1. The main purpose of the authors was to explore associations between a disc size change and other morphological parameters. Indeed, many non-ophthalmic and game-changing parameters are associated with disc size change and other morphological parameters, such as the serum lipids 2 dietary factors (such as lutein, zeaxanthin, and omega-3 fatty acids) 2-4, medications (such as lipid-lowering agents) 2, genetic susceptibility, body mass index, age and sex 3, among which only age and sex are addressed in their retrospective analysis.

According to the authors, decrease in the ophthalmoscopic disc size in the myopic eyes during the 10-year follow up, is likely related to a shift of the Bruch’s membrane opening as the inner of the three optic nerve head canal layers into the direction of the fovea. While their interpretations can be partly true, their attributed mechanism is subject to many biases.

Firstly, changes in ophthalmoscopical optic disc size and Bruch’s membrane are a function of macular pigment optical density 5-7, which in turn is a function of dietary carotenoid intake 8;9. Tong et al 10 have shown before that macular pigment optical density (MPOD) is inversely associated with axial length in Chinese subjects with myopia, suggesting that carotenoid intake, particularly lutein, is associated to axial length as well. Another study with a smaller sample size (45 eyes of 32 patients) with a different mean a...

• 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.

• Response to Martel et al. on visual hallucinations in sight loss

Martel et al. report the prevalence, features and risk factors of visual hallucinations following eye removal (1). The findings indicate that visual hallucinations may be a significant and prevalent association of eye amputation, occurring in around one-third of cases. Throughout the paper, visual hallucinations are referred to as phantom visions, and categorised under the broad catchment of the phantom eye syndrome that includes pain and tactile sensations as well as visual hallucinations. Although the authors speculate phantom visions could be considered a subtype of Charles Bonnet syndrome (CBS) they are reluctant to refer to them as CBS, perhaps because of the longstanding debate as to whether CBS should be used to refer to a specific type of visual hallucination or a specific underlying cause (2,3). Where CBS is used to refer to a specific hallucination type, it is typically reserved for complex hallucinations and excludes the simple, ‘elementary’ hallucinations described as the most common experiences following enucleation. The consequence is that a range of terms have evolved to describe symptoms that have the same cause, adding confusion to the literature and hindering research and extensive efforts to raise awareness and establish appropriate patient management pathways for people with visual hallucinations (4-6).

It is our opinion that both the simple and complex visual hallucinations described in the study should be referred to as Charles Bonnet syndrome....

• Macular hole surgery should be prioritised, not delayed by observation.

We would like to congratulate Uwaydat et al. on their large series of spontaneously closed macular holes (MH), which adds new information to the literature.(1) It reinforces the observation that traumatic MH can spontaneously close and that a period of observation in these eyes, where the results of surgery are not clear, is a worthwhile option. However, we disagree with their conclusion that eyes with recent onset small primary MHs should also be observed. The authors don’t suggest a time period for observation but found that the median time for closure for these small holes was 4.4 months.

The report by Uwaydat et al. has 40 authors and the 60 cases of idiopathic MH were collected over at least a two-year period. Assuming a conservative number of 25 MH cases seen per surgeon per annum, this would give a spontaneous closure rate of ~3%, which is similar to the published literature as the authors review in their article.

MH are known to enlarge with time, even in the short term. Madi et al, reported that 83% enlarged, by a median of 105 microns in 8 weeks. (2) Similarly, Berton et al recently estimated that holes less than 250 microns enlarge by a mean of 1.67 microns per day, resulting in a similar 100-micron increase in 2 months.(3)

The anatomical and visual outcomes of surgery are dependent on MH diameter and duration. Holes greater than 300 microns, and with a duration more than four months are less likely to regain 0.3 logMAR or better.(4)...

• Short-term real-world outcomes following intravitreal brolucizumab for neovascular AMD: SHIFT study- SAFETY Analysis

Dear Editor,
With great excitement, we read the original article titled “Short-term real-world outcomes following intravitreal brolucizumab for neovascular AMD: SHIFT study” by Bulirsch et al.1 We congratulate the authors on their detailed analysis and on adding another important real world data related to brolucizumab usage. As we are still trying to understand the pathogenesis of brolucizumab related immunogenicity and the population at risk,2-4 it would be very helpful for the readers if the authors could share the following information.

1. Were the 7 eyes in which IOI was recorded have history of any other autoimmune systemic diseases such as arthritis, thyroid abnormalities etc ?
2. It would be helpful if the authors could clarify if the 4 eyes that had intermediate uveitis and vitreous cells underwent fluorescein angigraphy or wide filed imaging to rule out the possibility of peripheral retinal vasulilits.
3. It would be helpful for the readers if we could know the indication of using subconjunctival dexamethasone in four cases?
4. After treatment, were all the patients who had vitritis completely free of cells/inflammation on clinical examination or were they asymptomatic?

Ashish Sharma, Nilesh Kumar, Nikulaa Parachuri
Lotus Eye Hospital and Institute, Coimbatore, TN, India

References
1. Bulirsch LM, Saßmannshausen M, Nadal J, et al Short-term real-world outcomes following intravitreal brolucizumab for neovas...

• 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...

• 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...