Shallow and bullous retinal pigment epithelium elevations in age-related macular degeneration.

OBJECTIVE

To assess prevalence and associations of shallow retinal pigment epithelium (RPE) elevations (RPEEs) and bullous RPE detachments (RPEDs).

METHODS

Macular optical coherence tomographic images taken in the population-based Beijing Eye Study were examined for the presence of RPEEs/RPEDs.

RESULTS

In the study cohort of 953 eyes (mean age:63.3 ± 9.3years), RPEE/RPED prevalence increased from 0/376 (0%) in the normal group and 0/373 (0%) in the group with early AMD stage, to 33/199 (16.6%;95%CI:11.4,21.8) and 1/5 (20.0%;95%CI:0.0,75.5) in intermediate and late AMD, respectively. In intermediate AMD, prevalences of RPEEs and RPEDs were 30/199 (15.1%;95%CI:10.0,20.2) and 9/199 (4.5%;95%CI:1.5,7.5), respectively. Higher total RPEE/RPED prevalence was associated with higher AMD stage (OR:55.3;95%CI:14.4,327;P < 0.001), higher drusen number (OR:1,05;95%%CI:1.02,1.07;P < 0.001), lower prevalence of external limiting membrane defects (OR:0.19;95%CI:0.05,0.57;P = 0.003), in addition to male sex (OR:11.0;95%CI:3.37,45.5;P < 0.001) and higher serum concentration of triglycerides (OR:1.48;95%CI:1.20,1.89;P < 0.001). RPEE/RPED prevalence was not significantly associated with choroidal thickness as a whole (P = 0.55) or separated in a large-vessel choroidal layer (P = 0.86), medium-sized vessel layer (P = 0.66) or small-vessel layer (P = 0.24), prevalence (P = 0.97) and location of any intraretinal hyperreflective foci, and prevalence of reticular pseudodrusen (P = 0.57).

CONCLUSIONS

Any RPEE/RPED, RPEEs and RPEDs were found in 16.6%, 15.1% and 4.5% of eyes with intermediate AMD, respectively, with a higher RPEE/RPED prevalence correlating with higher drusen number, lower prevalence of external limiting membrane defects and higher serum concentration of triglycerides. The statistical independence of RPEEs/RPEDs from the prevalences of reticular pseudodrusen and intraretinal hyperreflective foci point to differences in their etiologies.