Investigation of early inner retinal layer changes in hydroxychloroquine users without evident retinopathy: A...

Area of Science:

• Ophthalmology
• Retinal Imaging
• Pharmacological Toxicity

Background:

• Hydroxychloroquine (HCQ) is widely used for autoimmune conditions.
• Ocular toxicity is a known risk, typically affecting outer retinal layers.
• Early detection of subclinical changes is crucial for preventing vision loss.

Purpose of the Study:

• To investigate early structural changes in the inner retina and vasculature of patients on HCQ before outer retinal toxicity is evident.
• To compare macular ganglion cell complex (GCC), peripapillary retinal nerve fiber layer (RNFL), and macular vessel density (MVD) between HCQ users and healthy controls.

Main Methods:

• Comparative cross-sectional study involving 42 HCQ users (<5 mg/kg) and 41 age-matched healthy controls.
• Swept-source optical coherence tomography (SS-OCT) for macular GCC and peripapillary RNFL assessment.
• OCT angiography for macular vessel density (MVD) analysis.

Main Results:

• Significant thinning of superior, inferior, and total macular GCC was observed in HCQ users compared to controls (p < 0.05).
• No significant differences in peripapillary RNFL or MVD were found between groups.
• Patients on HCQ for ≥ 8 years showed reduced GCC thickness and superior RNFL thickness compared to shorter-term users and controls.

Conclusions:

• Chronic HCQ use, particularly beyond eight years, is associated with significant inner retinal thinning (GCC) even in the absence of overt retinopathy.
• Inner retinal layer assessment should be considered in comprehensive ophthalmic screening for long-term HCQ users.
• Early detection of subclinical inner retinal changes may allow for timely intervention to mitigate potential vision impairment.