Man presents with progressive blurred vision in left eye
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A 58-year-old African American man was referred to the retina clinic with a complaint of progressive blurred vision in the left eye. He was functionally monocular due to a history of refractive amblyopia in the right eye.
His ocular history was otherwise notable for a brunescent cataract complicated by phacomorphic glaucoma in the right eye, controlled on pilocarpine and dorzolamide-timolol eye drops. His medical history was significant for type 2 diabetes, hypertension, bipolar disorder and well-controlled HIV. Systemic medications included amlodipine, bupropion, dulaglutide, duloxetine, lamotrigine, lisinopril, tamsulosin and bictegravir/emtricitabine/tenofovir alafenamide. He had no surgical history, no pertinent family history and no history of trauma. Drug allergies included trimethoprim/sulfamethoxazole and quetiapine. His complete ocular and systemic review of systems was negative, including flashes, floaters, pain, diplopia or metamorphopsia.
Source: Simon D. Archambault, MD, MSc, and Kendra Klein-Mascia, MD
Examination
Upon examination, best corrected visual acuity was hand motion in the right eye and 20/50 in the left eye. IOP was within normal limits. Both pupils were reactive to light without an afferent pupillary defect. Extraocular eye movements were full and painless. Confrontation visual fields were full in the left eye. The anterior segment slit lamp examination was notable for a brunescent cataract in the right eye and moderate nuclear sclerotic cataract in the left eye. There was no view posteriorly in the right eye.
Dilated fundus examination of the left eye revealed a healthy disc with sharp margins and no vitreous cells or debris. There were subtle yellow central foveal pigmentary changes but no drusen, hemorrhages or other retinal lesions (Figure 1). The vessels were normal in course, and the peripheral retina was flat without obvious breaks, tears, hemorrhages or lesions.
Imaging
B-scan ultrasonography in the right eye revealed no significant vitreous opacities, intraocular masses or retinal detachment. OCT of the macula in the left eye demonstrated a focal area of foveal atrophy with attenuation of the outer retinal structures, including the ellipsoid zone, interdigitation zone and retinal pigment epithelium (Figure 2). OCT angiography confirmed no evidence of choroidal neovascularization in the left eye (Figure 3). Fundus autofluorescence demonstrated central hypoautofluorescence surrounded by a rim of hyperautofluorescence (Figure 4).
What is your diagnosis?
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Foveal atrophy
The differential diagnosis for a patient with central foveal atrophy and pigmentary changes with corresponding outer retinal atrophy on OCT includes photopic maculopathies (solar retinopathy and laser retinopathy), central serous retinopathy, vitreoretinal traction, adult-onset vitelliform dystrophy, KCNV2-associated retinopathy, occult macular dystrophy, a spontaneously closed macular hole and alkyl nitrite (poppers) maculopathy.
The dense cataract in the right eye precluded the view posteriorly to evaluate for symmetric pathology. However, the patient denied prior ocular trauma or surgery and exposure to sungazing, laser pointers or retinotoxic medications. There was no evidence of choroidal thickening to suggest central serous retinopathy, and there was no evidence of current or prior vitreoretinal traction. Further, recent systemic evaluation included negative syphilis and tuberculosis serologies. On a more thorough social history, the patient reported prior and current use of the recreational drug alkyl nitrite, also known as poppers.
Workup and management
The patient was diagnosed with presumed drug-induced or poppers maculopathy and educated regarding abstaining from further use.
The patient was examined multiple times over the next 6 months, and although he reported no further drug use, he did not regain vision. Repeat OCT imaging demonstrated stable foveal and parafoveal atrophy with outer retinal disruption and photoreceptor loss (Figure 5). The patient eventually had cataract removal in the right eye due to glaucoma progression. His surgery was complicated by zonular dehiscence requiring same-day vitrectomy and lens fragment removal. His vision remains hand motion in the right eye.
Discussion
Alkyl nitrites, commonly referred to as poppers, have been used as recreational drugs to induce a transient state of euphoria and myorelaxation. Alkyl nitrite-containing solvents are legal to purchase in the U.S., and as of 2017, approximately 4% of the U.S. population reported having tried poppers. Common side effects include tachycardia, headache, hypotension and syncope from the drug’s vasodilatory effects. Rarely, popper use can result in retinal toxicity, which can lead to photoreceptor destruction through the toxic vasodilatory effects of nitrous oxide. Up to 2.2% of routine popper users report changes in vision, and retinal changes can be observed even after just one use.
Typically, patients will report a bilateral decrease in visual acuity within days to weeks after popper use. Visual acuity on presentation can range; however, on average patients present with 20/40 vision. As observed in our patient, subtle yellow foveal pigmentary changes can be observed on dilated exam along with the classic outer retinal disruption on OCT. Electroretinogram can occasionally demonstrate decreased signal representing global retinal dysfunction. The mainstay of treatment consists of immediate cessation of alkyl nitrite usage. With sustained abstinence, some patients have been reported to regain baseline visual acuity in 6 months with improved outer retinal appearance on repeat OCT.
A diagnosis of poppers maculopathy may be missed in patients who are monocular or if a thorough social history is not discussed. This case highlights the importance of considering alkyl nitrite toxicity in the differential for focal foveal outer retinal atrophy to ensure timely diagnosis and potentially limit the extent of permanent vision loss.
- References:
- Bartolo C, et al. Semin Ophthalmol. 2023;doi:10.1080/08820538.2022.2108717.
- Docherty G, et al. Can J Ophthalmol. 2018;doi:10.1016/j.jcjo.2017.10.036.
- González-Martín-Moro J, et al. Semin Ophthalmol. 2022;doi:10.1080/08820538.2021.1986552.
- Hamann T, et al. Graefes Arch Clin Exp Ophthalmol. 2022;doi:10.1007/s00417-021-05453-0.
- Le A, et al. J Psychoactive Drugs. 2020;doi:10.1080/02791072.2020.1791373.
- Prestage G, et al. J Sex Med. 2009;doi:10.1111/j.1743-6109.2009.01323.x.
- For more information:
- Edited by Jonathan T. Caranfa, MD, PharmD, and Angell Shi, MD, of New England Eye Center, Tufts University School of Medicine. They can be reached at jcaranfa@tuftsmedicalcenter.org and ashi@tuftsmedicalcenter.org.
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