Didanosine-Associated Retinal Toxicity (DART) Amongst HIV-Positive Patients: a Case Series and Literature Review

Abstract

The aim of this study is to report on didanosine-associated retinal toxicity (DART) in four adult patients with human immunodeficiency virus (HIV) identified incidentally during routine diabetic eye screening and review all reported cases to date. This study is a retrospective, observational, case series from two health institutions with a review of published literature. DART is often asymptomatic, and patients have good vision (mean visual acuity 6/9), but in advanced cases, severe visual field defects can occur. Fundal changes range from mild granular pigmentary mottling to patches of mid-peripheral chorioretinal atrophy. Continuous expansion of chorioretinal degenerative changes posteriorly may lead to significant macular involvement as demonstrated in two of our cases. Despite cessation of therapy, DART was progressive in approximately 25% of reported cases. Our cases were incidentally discovered during routine diabetic eye screening and did not report any ocular symptoms prior to referral. Given the initial asymptomatic nature of DART, we believe that the true prevalence of the disease may be higher than previously thought. It may be prudent to screen and follow-up patients with a history of DDI use. We demonstrate the utility of multimodal imaging, optical coherence tomography, electrodiagnostic testing and visual fields in evaluating the effects of DART.

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

“…Didanosine-related retinal toxicity is usually asymptomatic, and patients retain adequate vision [6]; nevertheless, in advanced cases, the visual field may be significantly compromised [18]. The patient in our situation had undergone treatment with didanosine for seven years (2004-2011) and then stopped 11 years ago; yet, the pathological picture is perfectly compatible with the drug's toxicity.…”

“…Didanosine-induced retinal toxicity was first recorded in 1992 with a report of three immunocompromised children treated with didanosine who developed symmetrical bilateral peripheral retinal atrophy that spared the macula. Numerous case reports have documented a characteristic pattern of didanosine-induced retinopathy in HIV-infected individuals, including symmetrical bilateral mid-peripheral concentric retinal atrophy anterior to the posterior pole [5,6,[17][18][19][20]. Whitcup et al demonstrated the absence of macular damage in a child taking didanosine with a histological report of a normal structure of the macular, choriocapillaris, and retinal pigment epithelium [21].…”