Imaging of Hydroxychloroquine Toxicity with Fluorescence Lifetime Imaging Ophthalmoscopy

Quantitative Fundus Autofluorescence in Systemic Chloroquine/Hydroxychloroquine Therapy

“…Our proposed hypothesis is that the drug itself or its metabolic by-products are autofluorescent 46 and stored within retinal cells or adjacent tissue, supported in several ways by findings in animal models. First, early studies found that chloroquine deposition is related to pigmented tissue (iris, RPE, choroid), although absent in nonpigmented tissue and albino animals.…”

“…Recently, several groups reported prolonged lifetimes at the parafoveal region in patients with HCQ retinal toxicity. 46,70 However, whether FLIO could be a screening tool for early detection of CQ/HCQ induced maculopathy is still controversially discussed. 46,70 So far, in QAF studies, QAF8 (eight segments from a projected analysis grid, centered on the fovea, as introduced by Greenberg et al 31 ) was used for analysis.…”

“…46,70 However, whether FLIO could be a screening tool for early detection of CQ/HCQ induced maculopathy is still controversially discussed. 46,70 So far, in QAF studies, QAF8 (eight segments from a projected analysis grid, centered on the fovea, as introduced by Greenberg et al 31 ) was used for analysis. As shown in our study, especially in the maculopathy patients, QAF8 analysis does not capture the affected areas and more flexible analysis patterns (narrowing of the analysis field, flexible dimensions, free hand tools) are warranted to specifically analyze the respective areas.…”

Autofluorescence Lifetimes Measured with Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) Are Affected by Age, but Not by Pigmentation or Gender

“…FLIO has shown promising results as a prototype; it holds the potential to diagnose retinal diseases at early stages and may be on its way to become an important imaging modality in the future. [3][4][5][6][7][8][9][10][11][12]25 To use FLIO in clinical studies, background knowledge regarding specific influences on FLIO is important. A previous study by Dysli et al 16 nicely demonstrated that FLIO has good test-retest reliability, which holds true for miosis and mydriasis.…”

Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) in Patients with Choroideremia

“…Early FLIO lifeetime changes have been detected in Stargardt disease, patients with macular telangiectasia type 2 (MacTel), and patients who may develop retinal toxicity due to hydroxychloroquine (Plaquenil) supplementation. [20][21][22][23][24] Recently, early retinal changes in family members of patients with MacTel were found with FLIO. 24 Several other diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and Alzheimer disease, similarly exhibit altered FLIO lifetimes in early disease stages.…”