Journal of Clinical Toxicology
Open Access

Abstract

Detection of Retinal Changes in Patients on Long Term Chloroquine/Hydroxy Chloroquine Therapy Using Optical Coherence Tomography

Pratyusha G, Shashi Ahuja and VS Negi

Background: The best technique to diagnose chloroquine/ hydroxychloroquine-induced retinopathy changes at the earliest remains ambiguous at present. In this study, we evaluated the time-domain optical coherence tomography (OCT) to identify retinal changes associated with chloroquine and hydroxychloroquine.
Methods: One hundred patients with immunological diseases were included in the study. Fifty of them had been on chloroquine and/or hydroxychloroquine therapy for at least five years and the other 50 patients as controls. Detailed ophthalmic examination including Amsler grid , colour vision , automated threshold white perimetry using 10-2 protocol on Humphrey field analyzer, fluorescein angiography when indicated and time domain Optical Coherence Tomography was done.
Results: A statistically significant thinning was noted in the superior and inferior quadrants of the parafoveal area. Six patients had changes in fundus. When cases with normal and abnormal fundus were analyzed individually, a statistically significant thinning was noted in the inferior parafoveal region in patients on chloroquine/ hydroxychloroquine having normal fundus when compared to the controls Amsler grid, colour vision, central 10-2 perimetry, FFA were all normal in these patients. There was no significant retinal nerve fiber layer thinning in the peripapillary region Temporal macular thickness was significantly thinner in patients who received the drugs for more than 8 years. Conclusions: Time domain OCT can be used to detect pre- clinical changes of chloroquine/ hydroxychloroquine -induced retinopathy. All patients on long term use of these drugs must undergo regular examinations to diagnose early toxicity.