Intensity-based optoretinography reveals sub-clinical deficits in cone function in retinitis pigmentosa

Area of Science:

• Ophthalmology
• Cellular Biology
• Medical Imaging

Background:

• Clinical tools for retinitis pigmentosa (RP) diagnosis often lack sensitivity, missing early photoreceptor disruption.
• Adaptive optics scanning light ophthalmoscopy (AOSLO) offers high-resolution imaging for detailed structural and functional assessment of photoreceptors.

Purpose of the Study:

• To evaluate intensity based optoretinography (iORG) via AOSLO for assessing photoreceptor structure and function in individuals with and without RP.
• To compare the sensitivity of iORG to traditional methods like macular integrity assessment (MAIA) for detecting early functional deficits.

Main Methods:

• AOSLO was used to acquire iORG in 15 healthy individuals and 7 with RP.
• Photoreceptor structure was quantified by cone nearest neighbor distance (NND) and cone outer segment length (measured via OCT-derived LRPs).
• iORG functional measures were compared with MAIA microperimeter retinal sensitivity.

Main Results:

• Individuals with RP showed increased NND and decreased outer segment length with eccentricity.
• RP participants exhibited reduced iORG amplitudes compared to controls, with greater reduction in peripheral retina.
• iORG detected earlier functional deficits than MAIA, which was more sensitive to later disease stages.

Conclusions:

• iORG is a valuable tool for detecting sub-clinical cone dysfunction across all stages of RP.
• iORG's sensitivity supports its future use in identifying cells for targeted cellular therapies in RP.