Fundus Photography – Trans-Palpebral Illumination

Fundus photography is essential in ophthalmology to screen, diagnose, and manage eye diseases. Wide-field fundus photography has demonstrated its utility in the clinical management of eye diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, hypertensive retinopathy, retinal detachments, and vascular pathologies (vascular occlusions, vasculitis, etc.) with ocular metastasis. Choroidal and retinal imaging can be a valuable supplement to traditional retinal imaging for better managing choroidal disorders.

Multiple spectral imaging (MSI) technology employs multiple wavelengths ranging from visible to near-infrared to visualize the choroidal fundus. However, current MSI systems have a limited field of view.

For wide-field fundus photography, trans-palpebral illumination is a scleral contact-free alternative to trans-pars-planar illumination. The trans-pars-planar illuminator does not make direct contact with the sclera. Instead, it delivers light through the eyelid. It promises a simple solution to achieve affordable wide-field imaging without the risk of contamination from direct contact of the lens with the eyeball.

However, because the light efficiency delivered through the eyelid and sclera is highly wavelength dependent, the practical application of trans-pars-planar illumination for true-color retinal imaging is challenging.

The researchers validated the choroid’s multiple spectral imaging (MSI) using near-infrared (NIR) light illumination. They also tested the feasibility of true-color retinal imaging using efficiency-balanced visible light illumination.

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