Ultrasonic chorioretinopathy: a chloroquine vs control study

Area of Science:

• Ophthalmology
• Biophysics
• Pharmacology

Background:

• Melanin in the retinal pigment epithelium plays a role in energy absorption.
• High-frequency ultrasound can induce chorioretinal lesions.
• Chloroquine is known to bind to melanin.

Purpose of the Study:

• To investigate the effect of subretinotoxic chloroquine doses on the susceptibility of the rabbit retina to high-frequency ultrasound-induced injury.
• To explore the potential role of melanin in mediating ultrasound energy absorption in the retina.

Main Methods:

• High-frequency ultrasound was used to create chorioretinal lesions in pigmented rabbits.
• Two groups were studied: a control group and a group treated with subretinotoxic doses of chloroquine.
• Lesion thresholds were compared between the two groups.

Main Results:

• The untreated control group developed chorioretinal lesions at lower ultrasound energy levels compared to the chloroquine-treated group.
• This indicates that chloroquine treatment increased the retina's resistance to ultrasound-induced damage.

Conclusions:

• Chloroquine, even at subretinotoxic doses, alters melanin's function in processing ultrasonic energy.
• Melanin's ability to convert ultrasonic energy to thermal energy may be inhibited by chloroquine binding.
• This interaction suggests a mechanism by which chloroquine can affect retinal sensitivity to ultrasound.