Central Retinal Sensitivity Decline in RPGR-Related Retinal Phenotypes

Area of Science:

• Ophthalmology
• Genetics
• Retinal Degeneration

Background:

• RPGR-associated retinopathy is a spectrum of inherited retinal diseases.
• Understanding the natural history of vision loss is crucial for patient management and therapeutic development.

Purpose of the Study:

• To characterize central retinal sensitivity decline in RPGR-associated retinopathy.
• To compare disease progression between RPGR-associated cone-rod dystrophy (CORD) and rod-cone dystrophy phenotypes using microperimetry.

Main Methods:

• Retrospective cohort study of 50 patients with genetically confirmed RPGR mutations.
• Assessed central retinal function using a standard 68-point MAIA microperimeter grid.
• Analyzed longitudinal decline rates of mean sensitivity across central 4 (MS4) and 16 (MS16) loci.

Main Results:

• CORD patients showed significantly faster annual decline in MS16 (10.8%) and MS4 (14.9%) compared to rod-cone patients (5.1% and 4.1%, respectively).
• Median survival age to total sensitivity loss was earlier for CORD patients (25.1 years for MS16, 27.2 years for MS4) versus rod-cone patients (33.1 years for MS16, 33.3 years for MS4).
• CORD patients had a 7.2- to 8.2-fold increased risk of central vision loss compared to rod-cone patients.

Conclusions:

• Significant differences in functional decline rates exist between RPGR retinopathy phenotypes.
• CORD patients face a substantially higher risk of early central vision loss.
• Microperimetry is a sensitive outcome measure for RPGR-associated retinopathy, providing valuable data for clinical trials and patient counseling.