Inner and outer retinal changes in retinal degenerations associated with ABCA4 mutations

Area of Science:

• Ophthalmology
• Genetics
• Medical Imaging

Background:

• ABCA4-RD is a genetic retinal degeneration.
• Understanding its microstructural changes is crucial for visual function assessment.

Purpose of the Study:

• Investigate in vivo retinal microstructure in ABCA4-RD.
• Assess structural abnormalities and their impact on visual function.
• Examine the progression of retinal changes over time.

Main Methods:

• Spectral-domain optical coherence tomography (OCT) in 45 patients with ABCA4-RD.
• Analysis of inner and outer retinal layer thicknesses.
• Longitudinal OCT measurements (mean 4 years) and visual function testing (perimetry).

Main Results:

• Observed a spectrum of photoreceptor thinning and inner retinal changes, including inner nuclear layer (INL) thickening.
• INL thickening correlated with photoreceptor loss.
• Longitudinal data showed variable progression of outer nuclear layer (ONL) thinning and INL thickening.
• Visual function correlated with photoreceptor loss, even with INL thickening.

Conclusions:

• Inner retinal laminar abnormalities are a feature of ABCA4-RD, similar to other photoreceptor diseases.
• These changes are likely secondary to retinal remodeling from photoreceptor loss.
• Visual loss in affected regions aligns with predictions based solely on photoreceptor loss.