Retinal and Choroidal Morphological Features Influencing Contrast Sensitivity in Retinitis Pigmentosa.

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Diseases

Background:

• Retinitis pigmentosa (RP) is a group of inherited disorders that cause progressive vision loss.
• Optical coherence tomography (OCT) and OCT-angiography (OCTA) are advanced imaging techniques used to visualize retinal structures.
• Contrast sensitivity (CS) is a crucial measure of visual function, often impaired in retinal diseases.

Purpose of the Study:

• To identify specific morphological features visible on OCT and OCTA that correlate with reduced contrast sensitivity (CS) in patients diagnosed with retinitis pigmentosa (RP).
• To investigate the relationship between retinal layer thickness, vascular density, and visual function in RP.

Main Methods:

• A cross-sectional study involving 18 patients (18 eyes) with RP.
• Contrast sensitivity was measured using the CSV1000-E under mesopic conditions.
• Retinal imaging was performed using spectral-domain OCT (SD-OCT) and swept-source OCT (SS-OCT), including OCT angiography (OCTA) to analyze retinal layers, foveal avascular zone, and vascular density (VD).

Main Results:

• Central and nasal retinal nerve fiber layer (RNFL) thickness were significant predictors of CS at higher spatial frequencies (12 and 18 cycles/degree).
• Vascular density (VD) in the deep retinal plexus was strongly associated with CS at 6 and 12 cycles/degree.
• Outer plexiform layer (OPL) and retinal pigment epithelium (RPE) thickness also showed correlations with CS at specific frequencies.

Conclusions:

• RNFL thickness and deep vascular plexus density are key indicators of contrast sensitivity deficits in retinitis pigmentosa.
• OCT and OCTA imaging reveal important structural correlates of visual impairment in RP patients.
• These findings can aid in understanding disease progression and developing targeted therapies.