Age-related changes in macular vessels and their perfusion densities on optical coherence tomography angiography

To evaluate age-related changes in macular vessels and their perfusion densities using optical coherence tomography angiography (OCTA).

A total of 108 eyes of 54 healthy subjects between the age group of 11 to 60 years having unaided visual acuity of 20/20 were studied on spectral domain OCTS using 3 * 3 mm macula protocol. These subjects were divided into 5 groups; Group 1: 11-20 years, Group 2: 21-30 years, Group 3: 31-40 years, Group 4: 41-50 years, and Group 5: 51-60 years. An early treatment diabetic retinopathy study (ETDRS) grid overlay at the macula was used to calculate changes in different quadrants of the superficial retinal plexus.

A total of 98 eyes of 49 patients were considered for the final analysis. The vessel density values decreased from the second to the sixth decade in all four quadrants (except the third decade, where a slight increase was noted). The total vessel density decreased from 168 ± 78 mm^-1 (group 1) to 131.47 ± 18.32 mm^-1 (group 5). A similar reduction pattern in perfusion density was seen in each quadrant from the second to the sixth decade. The total perfusion density reduced from 309 ± 15.63% (group 1) to 283.05 ± 45.23% (group 5). The foveal avascular zone area was 0.18 ± 0.09 mm² in group 1, 0.33 ± 0.13 mm² in group 2, 0.30 ± 0.10 mm² in group 3, 0.38 ± 0.05 mm² in group 4, and 0.46 ± 0.06 mm² in group 5.

In our population, macular vessel density appears to decrease noticeably from the fourth decade onwards but a statistically significant decrease was observed only from the fifth decade onwards. However, it was not uniform along with all the quadrants. Similarly, the percentage of perfusion density dropped from the fourth decade but these values also varied among the different quadrants.