Assessment of the microvasculature in poppers maculopathy

Poppers maculopathy missed in a patient with cataract highlights the importance of preoperative optical coherence tomography

Poppers maculopathy is a complication of alkyl nitrate (poppers) inhalation. It presents with non-specific symptoms and variable signs, which can make it difficult to diagnose. We present a case of coexisting cataract and poppers maculopathy in a patient. He had vague visual symptoms that were attributed entirely to his cataract and he went on to have cataract surgery. Suboptimal postoperative visual acuity and normal clinical examination triggered further investigation with spectral-domain optical coherence tomography (SD-OCT), after which poppers maculopathy was diagnosed. We highlight the importance of performing OCT in the preoperative assessment of a cataract patient, especially where the cataract is mild and may not fully account for symptoms. The patient showed complete visual recovery on drug cessation despite ongoing maculopathy on OCT scans.

Analysis of Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) Parameters in Young Adults after SARS-CoV-2 Infection (COVID-19) Compared with Healthy Young Controls

Purpose: To compare retinal changes in young adults with previous SARS-CoV-2 infection with healthy young controls using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Methods: This prospective single-center study was conducted at the University Hospital of Zurich, Zurich, Switzerland. Participants were imaged from May to November 2021 using the SOLIX device (Visionix International SAS, Pont-de-l’Arche, France). We performed 12 mm × 12 mm, 6.4 mm × 6.4 mm, 6 mm × 6 mm and 3 mm × 3 mm OCT and OCTA scans, as well as fundus photography of each participant’s eyes. Results: In total, 466 participants were imaged. Of these, 233 were healthy controls with negative RT-PCR tests for SARS-CoV-2, 168 were young adults who had a SARS-CoV-2 infection at least 180 days previously, 19 were participants who had a SARS-CoV-2 infection < 180 days previously, and 46 were participants with asymptomatic SARS-CoV-2 infection (i.e., serologically positive but with no symptoms). Compared with healthy controls, statistically significant differences were found for OCTA recordings of the optic disc for the whole image (WI) and WI capillary vessel density, with both being higher in the SARS-CoV-2 group. Conclusion: Statistically significant results were only observed for selected variables, and in parts, only unilaterally, with relatively large p values (p = 0.02–0.03). Thus, we did not interpret these as clinically significant, leading to the conclusion that young and otherwise healthy individuals (mainly men) seem to recover from mild COVID-19 infections with no ophthalmological residues.

Relationship of Vessel Density to Vessel Length Density in Patients with Treated Fabry Disease

BACKGROUND

Fabry disease (FD) is a potentially lethal lysosomal disorder with systemic vascular changes. Previous studies demonstrated retinal vascular involvement using optical coherence tomography angiography (OCTA) in affected patients; Aim: To analyze and quantify the retinal vasculature measuring vessel density (VD), vessel length density (VLD), and the ratio of VD to VLD (VD/VLD) in superficial capillary plexuses (SCP) and deep capillary plexuses (DCP) using OCTA in patients with FD and to show whether they differ from healthy controls (HC); Patients and methods: Single-center, retrospective, consecutive cohort study of patients with genetically proven FD. Patients underwent an ophthalmological examination including OCTA. VD, VLD, foveal avascular zone (FAZ), and the VD/VLD were compared to an HC group using a linear mixed model; Results: A statistically significant difference in the VLD and VD/VLD of DCP was observed between the two groups (p < 0.001). Using ROC curves with AUC and Youden's Index, a cut-off value for differentiating both groups using VD/VLD in DCP FD with high specificity and high sensitivity was established; Conclusions: FD and HC groups seem to be separable using the VD/VLD ratio in DCP. This new biomarker might differentiate changes in the retinal microvasculature that are not detectable by VD or VLD alone.

[Exogenously induced retinopathies]

Exogenously induced retinopathies can be caused by consumation of stimulating substances, systemic or ocular medications, vaccinations, light or irradiation. Some of the effects are transient, whereas other effects induce irreversible toxic reactions. Retinal damage may develop either acutely with obvious relation to the damaging cause, but often may take a long duration of repeated use of a substance or medication. External stimulants (e.g. nicotine, alcohol, poppers, methanol) are the most frequent cause of exogenously induced retinal damage. Side effects from systemic drugs (e.g. hydroxychloroquine, ethambutol, MEK-, ERK-, FLT3-, checkpoint inhibitors, didanosin, pentosanpolysulfat sodium) or intravitreally applied drugs (e.g. antibiotics, VEGF-inhibitors) are less frequent. Ocular side effects associated with vaccinations are rare. Ambient light sources induce no damaging effects on the retina. Incorrect use of technical or medical light sources (e.g. laser pointers) without adherence to safety recommendations or unshielded observation of the sun might induce permanent retinal damage. Local or external irradiation might induce retinal vascular damage resulting in radiation retinopathy.

Exogen bedingte Retinopathien

Exogen bedingte Retinopathien werden am häufigsten durch externe Stimulanzien, seltener durch unerwünschte Arzneimittelwirkungen systemisch oder intravitreal eingesetzter Medikamente und noch seltener durch Impfungen oder die Einwirkung von Lichtstrahlung verursacht. Die Kenntnis exogener Ursachen und ihre mögliche Symptomatik ist zur Prophylaxe oder zur Früherkennung schädigender Wirkungen und zur adäquaten Beratung der Patienten wichtig.

'Poppers Maculopathy' and the adverse ophthalmic outcomes from the recreational use of alkyl nitrate inhalants: a systematic review

OBJECTIVE

The aim of this systematic review and meta-analysis was to provide an overview of reported cases of poppers maculopathy and a statistical analysis of the clinical presentations, anatomical changes and treatment and follow-up of the rare disease.

METHODS

A systematic search of CINAHL, Embase and PubMed databases was conducted, including a search of the grey literature. Data were pooled to provide a summary of the clinical characteristics and outcomes of poppers maculopathy. Studies were critically appraised using the Joanna Briggs Institute or the Authority, Accuracy, Coverage, Objectivity, Date, Significance checklists.

RESULTS

Of the 493 articles obtained, 32 were included, consisting of 113 participants with a mean age of 40.2. Most patients were male with bilateral maculopathy and presented with either vision loss or a visual disturbance. Cessation of popper use was the most common form of management prescribed. The mean VA at baseline was 0.22 (logMAR units). For those followed-up, the mean VA significantly improved from 0.24 to 0.11 (Z = -5.800, p = <0.001). Bilateral yellow foveal spots were viewed on fundoscopy in 53 patients, and a sub-foveal disturbance of the ellipsoid layer was reported on spectral domain optical coherence tomography in 89 patients. By 6 months, SD-OCT anatomical changes mostly improved or resolved.

CONCLUSION

Recreational users of poppers who develop maculopathy generally present with vision loss or a visual disturbance secondary to foveal disruption. Patients have a good visual prognosis, with cessation of poppers potentially having a role in improved outcomes. With the high prevalence of use among gay and bisexual men, awareness of related maculopathy and presenting symptoms by clinicians is important to mitigate side effects.