A Rare Case of Didanosine-Induced Mid-Peripheral Chorioretinal Atrophy Identified Incidentally 11 Years after the Drug Cessation

Abstract

Objective: This article aims to describe a unique case of didanosine-induced retinal degeneration that was discovered 11 years after the drug withdrawal. Case report: The patient is a 42-year-old woman with a medical history of HIV and hepatitis C virus since 2004. She has been prescribed antiretroviral therapy since then. For the first seven years (2004-2011), the patient was prescribed a combination therapy consisting of didanosine, efavirenz, and lamivudine. The protocol was changed to atripla (efavirenz, emtricitabine, and tenofovir) from 2011 to 2021. Recently (October 2021-January 2021), the patient was prescribed eviplera (rilpivirin, emtricitabine, and tenofovir). In addition, her past medical history revealed Gougerot-Sjogren syndrome and rheumatoid arthritis. She was prescribed hydroxychloroquine (HCQ) (2009-2021) at a dose of 400 mg daily. She had no vision complaint. Results: During her routine HCQ screening at the eye clinic, University Hospital Bretonneau, Tours, France, the widefield colour fundus photograph showed well-defined symmetric mid-peripheral areas of chorioretinal atrophy sparing the posterior pole of both eyes. Furthermore, the widefield fundus autofluorescence illustrated mid-peripheral round well-demarcation hypoautofluorescent areas of chorioretinal atrophy of both eyes. Conversely, the macular optical coherence tomography (OCT) was normal. Many of her drugs are known to be associated with retinopathy such as HCQ, tenofovir, efavirenz, and didanosine. Because our data corroborate peripheral retinal damage rather than posterior pole damage, this case report is compatible with didanosine-induced retinopathy rather than HCQ, efavirenz, or tenofovir retinal toxicity. Conclusions: All HIV patients who are presently or were previously on didanosine therapy should have their fundus examined utilising widefield fundus autofluorescence and photography.

Keywords: didanosine; retinopathy; widefield fundus autofluorescence; widefield fundus photography.

Figure 1

Ultra-widefield fundus photographs of the right (A) and left (B) eye performed using the optos camera showed well-delineated concentrical mid peripheral patches of chorioretinal atrophy sparing the macula in both eyes. Ultra-widefield short-wavelength fundus autofluorescence illustrated mid-peripheral round well-demarcated patchy loss of autofluorescence in both eyes (C,D). Macular Optical coherence tomography (OCT) photos showed no macular abnormality in either eye (E,F).

Figure 2

Farnsworth D-15 colour vision tests showed no abnormality in either eye (A,B). Goldmann kinetic visual field revealed (C) a superior temporal depression with the I4e isopter in the left eye and (D) absolute scotomas in the temporal mid-peripheral field between 30° and 60° in the right eye. A full-field electroretinogram (ERG) revealed moderate generalized rod and cone dysfunction in both eyes (E).

Figure 3

Static visual field test within the 12 central degree FAST 12 perimetry Metrovision visual field test showed no central field defects in either eye (A: left eye; B: right eye).