Original article BMJ Open Ophth: first published as 10.1136/bmjophth-2016-000015 on 25 January 2017. Downloaded from The prevalence of visual symptoms in poppers users: a global survey Andrew J Davies,1 Rohan Borschmann,2,3 Simon P Kelly,4 John Ramsey,5 Jason Ferris,6 Adam R Winstock7 To cite: Davies AJ, ABSTRACT Key messages Borschmann R, Kelly SP, Introduction and aims: The use of ‘poppers’ et al. The prevalence of (volatile alkyl nitrites) has been associated with the visual symptoms in poppers What is already known about this subject? development of visual symptoms secondary to the users: a global survey. BMJ " Specific macular features associated with Open Ophth 2016;1:1–6. development of maculopathy. There are currently no poppers abuse have been reported and are doi:10.1136/bmjophth-2016- data regarding the prevalence of this condition among increasingly recognised by retinal specialists on 000015 poppers users. The aim of this study was to quantify clinical imaging. " Prepublication history and the presence of visual symptoms among poppers What are the new findings? additional material is users from a global cohort. " This global study provides descriptive data on available. To view please visit Design and methods: The Global Drug Survey the visual symptoms that poppers users may the journal (http://dx.doi.org/ (GDS) conducts annual anonymous online surveys of experience. We also provide a review of all 10.1136/bmjophth-2016- drug and alcohol use. Within the 2012 GDS, questions published cases of poppers maculopathy to 000015) were inserted regarding the presence of visual date. symptoms in poppers users. How might these results change the focus of Received 29 June 2016 Results: The GDS received a total of 21 575 valid Revised 29 November 2016 research or clinical practice? Accepted 11 December 2016 responses, with a total of 17 479 from the UK, " The data provided will facilitate recognition of Australia, USA and Eurozone. Within these areas, 5152 this disorder by the wider clinical community (29.5%) had used poppers within their lifetime and and will influence future clinical studies. 1322 (7.6%) within the previous year. Of the ‘last year’ Importantly, these results are of considerable copyright. users, when asked the question: ‘Do you think poppers ocular public health relevance and may assist use has affected your eyesight?’, 29 (2.2%) people legislators regarding the manufacture and sale responded ‘yes’, 130 (10.0%) responded ‘maybe’ and of volatile nitrite products. 1146 (87.8%) responded ‘no (17 people did not 1 Department of answer). Both multiple choice and free-text responses Ophthalmology, Manchester regarding the nature of visual symptoms correlated Royal Eye Hospital, with the central visual disturbance that would be changed in recent years in response to Manchester, UK 2Melbourne School of expected from maculopathy. There was significant European legislation. In the UK, it is http://bmjophth.bmj.com/ Population and Global increased symptom prevalence with age reported that up to 10% of the general Health, The University of (likelihood ratio (2)=19.0; p<0.001). population have tried poppers, with 1% Melbourne, Melbourne, Discussion and conclusions: This study having done so within the past year.3 This Australia demonstrates that a small, yet significant from a public 3Murdoch Children’s rate is higher in the ‘clubbing’ (electronic health perspective, proportion of poppers users have dance music) and gay communities.4 5 In Research Institute, Royal visual symptoms. Clinical correlation is required to Children’s Hospital, many western countries poppers are illegal determine whether these reported symptoms are due Melbourne, Australia to sell for human consumption, yet not 4Department of to poppers associated maculopathy, or an alternative illegal to possess. They are therefore often on September 27, 2021 by guest. Protected Ophthalmology, Royal Bolton cause. Hospital, Bolton, UK sold for alternative uses such as video head 5St. George's University of cleaner or room deodorants and are typi- London, London, UK cally easy to purchase on the high street or 6 INTRODUCTION Institute for Social Science online. Research, University of ‘Poppers’ are substances of abuse belonging Queensland, Brisbane, to the volatile alkyl nitrite family of Poppers have previously been described Australia compounds. Inhalation of the fumes as low risk both physically and psychologi- 7 6 Department of Addictions, provides a brief sense of euphoria or cally. However, since 2010 there have been South London and Maudsley arousal.1 They have been in common use numerous case reports and case series from NHS Foundation Trust, Europe and Australia of poppers users who London, UK for several decades and are a global phenomenon, with reports from many developed visual symptoms secondary to western countries including those in macular pathology; a condition referred to Correspondence to 1 2 7–21 Dr Rohan Borschmann; Europe, North America and Australasia as ‘poppers maculopathy’. More than 50 rohan.borschmann@mcri. documenting their high incidence of abuse. cases have been described (see table 1), all edu.au The particular alkyl nitrite compound has of which share similar symptoms including Davies AJ, et al. BMJ Open Ophth 2016;1:1–6. doi:10.1136/bmjophth-2016-000015 1 Open Access BMJ Open Ophth: first published as 10.1136/bmjophth-2016-000015 on 25 January 2017. Downloaded from Table 1 Previously published cases of clinically confirmed poppers maculopathy Author/year Type of series Country Cases (n) Level of use Visual Findings and other features of impairment note (Snellen acuity) Vignal- Case series France 4 Varied Range 6/12– Nil clermont 6/15 et al/20107 Audo et al/ Retrospective France 6 Chronic (3–20 Range 6/7.5– 4/6 showed anatomical and 20118 observational (all HIV) years) 6/15 functional improvement with case series cessation Schulze- Cross-sectional France 10 Chronic (mean 6/9 or better 10/18 long-term poppers users Dobold€ et al/ observational 20 years) found to have changes 20129 study Davies et al/ Case series UK 7 Chronic 2 Range 6/6– 6/ Dose–response suggested 201210 Short term 5 12 long-term users = more severe maculopathy Krilis et al/ Case report Australia 1 Three-month 6/12 OD, 6/9 OCT normal, vision resolved 201311 history, OS within 24 hours fortnightly use Rabot et al/ Case report France 1 Nil 201312 Bruninx and Case report Belgium 1 Single use 6/9 OU Spontaneous resolution 6/6 Lepiece/ after 4 weeks 201313 Savary et al/ Case series France 2 Chronic 1 1. OU 6/6 ERG—mildly diminished 14 2013 Single use 1 2. OU 6/15 central response copyright. Asensio- Case report Spain 1 Nil Sanchez et al/201415 Gruener Case report UK 1 Not stated 6/12 OD, 6/18 No improvement on cessation et al/201416 OS at 6 months Clemens Case series Germany 2 Sporadic 1 1. 6/9, 6/15 Both pathological full field et al/201517 Chronic (1 2. 6/12, 6/15 ERG year) 1 http://bmjophth.bmj.com/ Pahlitzsch Retrospective Germany 7 1 Single use 1 Median 6/9 1=normal multifocal ERG et al/201318 observational (5 HIV) Chronic (2–25 Median 6/6 at final visit case series years) 6 Bral et al/ Retrospective Belgium 10 Not stated Not described 60% used sildenafil 201619 observational (7 HIV) case series Luis et al/ Case report UK 1 Single use 6/15 OD, 6/12 Partial resolution at 3 months, 201620 OS 6/9.5 on September 27, 2021 by guest. Protected Garcia-Bella Case report Spain 1 Habitual 6/9 OU Nil et al/201621 ERG, electroretinogram; OCT, optical coherence tomography; OD, right eye; OS, left eye; OU, both eyes. blurred vision, metamorphopsia, photopsia and fluctu- subtle. Causality, while difficult to prove with 100% ating vision. The range of visual impairment described certainty, is anecdotally agreed among ophthalmolo- is mild to moderate, with Snellen acuity levels typically gists, and has been interrogated in previous ranging from 6/9 to 6/12. The most useful diagnostic publications.10 Both short-term (including one-off) and tool is spectral domain optical coherence tomography long-term poppers users seem to be at risk of devel- (OCT) which demonstrated disruption of the subfoveal oping maculopathy. Published cases suggest a degree outer retinal layers in all cases described with the of dose–response, with more chronic users appearing exception of Krilis et al.11 Ophthalmoscopy can show a at greater risk of more profound and long-lasting yellow lesion at the fovea, although this may be very vision loss. It is not yet known whether the retinal 2 Davies AJ, et al. BMJ Open Ophth 2016;1:1–6. doi:10.1136/bmjophth-2016-000015 Open Access BMJ Open Ophth: first published as 10.1136/bmjophth-2016-000015 on 25 January 2017. Downloaded from damage is permanent, although several cases have had Ethics approval was granted by South London and long-term reduction in vision in spite of cessation of Maudsley Foundation Trust Research Ethics use.10 16 Committee. All data preparation and analysis were There are currently no data regarding the prevalence undertaken using Stata V.14 (StataCorp; College of poppers maculopathy among poppers users. The Station, Texas, USA). purpose of this study was to estimate the prevalence of visual symptoms in users of poppers from a global RESULTS perspective. This was achieved using data from the During the 2-month collection period, a total of 22 289 UK, Australia, the USA and the Eurozone which responses were made worldwide. After removing dupli- includes 19 countries from Europe who have adopted cate entries, those reporting no history of drug use and the Euro as their currency (Austria, Belgium, Cyprus, those reporting use of a non-existent drug (eg, Estonia, Finland, France, Germany, Greece, Ireland, Xenorap), a total of 17 479 valid responses were Italy, Latvia, Lithuania, Luxembourg, Malta, Nether- received from 22 countries.