Figure 5: Representative optical coherence tomography images of the foveal avascular zone area.

Shown are representative images of the superficial layer before (a,c) and after (b,d) processing. The foveal avascular zone (FAZ) area (mm²) of the superficial and deep layers was manually measured using built-in software, and the area was corrected using parameters including axial length, the flatter meridian, the steeper meridian, and the spherical equivalent refraction in Littmann’s formula. (a,b) Images of a 51-year-old woman with retinitis pigmentosa with superficial FAZ area of 0.340 mm² before correction, and of 0.237 mm² after correction. (c,d) Images of a 39-year-old male control with superficial FAZ area of 0.204 mm² before correction, and of 0.179 mm² after correction.