CNGA3-Related Achromatopsia: A 10-Year Follow-Up

<b>Purpose:</b> To describe long-term structural retinal changes in CNGA3-related achromatopsia using spectral-domain optical coherence tomography (SD-OCT) over a 10-year follow-up period. <b>Methods:</b> A single case was reviewed. <b>Results:</b> A 16-year-old girl with genetically confirmed CNGA3 mutations underwent annual SD-OCT imaging with concurrent assessment of best-corrected visual acuity (BCVA). Over the 10-year follow-up, BCVA remained stable; however, progressive foveal structural deterioration was observed. These included early external limiting membrane (ELM) hyperreflectivity and ellipsoid zone (EZ) disruption, followed by the development and enlargement of optically empty spaces, choroidal hypertransmission defects, and increasing hyperreflective foci. These findings were consistent with progression through a previously proposed OCT-based staging system for achromatopsia. <b>Conclusions:</b> This case demonstrates that CNGA3-related achromatopsia can exhibit clear structural progression on SD-OCT despite stable visual acuity, challenging the traditional view of the disease as stationary. SD-OCT is essential for detecting subtle but progressive foveal degeneration, and hyperreflective foci may represent an early marker of photoreceptor or retinal pigment epithelium compromise. These findings support further refinement and validation of OCT-based staging systems in CNGA3-related achromatopsia.