To compare visual acuities in autosomal recessive retinitis pigmentosa (ARRP) associated with variants in four rod phototransduction genes: PDE6A, PDE6B, CNGA1, and CNGB1.
Key Findings:
Patients with CNG-associated disease had better average VA compared to PDE-associated disease (age-adjusted p = 7.5 × 10−5).
Mean logMAR acuities at first visit were 0.10 for CNGA1, 0.34 for CNGB1, 0.45 for PDE6A, and 0.56 for PDE6B.
Significant differences in acuities were found: CNGA1 vs. PDE6A (p = 8 × 10−5), CNGA1 vs. PDE6B (p = 0.003), and CNGB1 vs. PDE6B (p = 0.003).
Interpretation:
VA appears better preserved in variants affecting rod CNG channels compared to those affecting rod phosphodiesterase, potentially due to different effects on intracellular calcium.
Limitations:
Relatively small numbers for some genes limit the power of some pairwise comparisons.
Lack of visual field data or analysis of retinal imaging.
Conclusion:
The study aids in understanding potential disease mechanisms and identifies potential windows for future therapeutic intervention.
by Vishanna Balbirsingh, Shaima A. Hashem, Michalis Georgiou, Siying Lin, Gavin Arno, Mariya Moosajee, Andrew R. Webster, Michel Michaelides, Omar A. Mahroo
