Abstract
Purpose: :
Prior to the invention of optical coherence tomography (OCT), Gass described the existence of subclinical circumpapillary drusen. Since these lesions are difficult to see on biomicroscopy, their prevalence is unknown. The purpose of this study was to use three-dimensional OCT to assess the incidence of peripapillary retinal pigment epithelial detachments (PPPED) in an asymptomatic population.
Methods: :
In this study, asymptomatic subjects (i.e. family members of patients) were prospectively recruited from our clinic waiting room over six months. Each subject completed a questionnaire prior to the acquisition of two undilated 45º fundus images and 4 undilated raster 3D-OCT scans (3x512x128, 1x1024x64) covering the macula and optic nerve from each eye using a 3D-OCT-1000 (Topcon Co, Tokyo). Two graders evaluated the fundus images for the presence of drusen, peripapillary atrophy (PPA), peripapillary pigment (PPP) and peripapillary PEDs and the 3D-OCT scans for peripapillary PEDs and drusen. The frequencies and locations of each of these findings were measured and subdivided by subject age.
Results: :
288 eyes from 146 subjects were included in the study. The mean age of participants was 38.0 years (range 18-90 yrs). Sixty percent of subjects were women. Fifty percent identified themselves as Hispanic, 18% as non-Hispanic white, 18% as Asian, and 4% as African American. PPPEDs were graded as present in 27% (77/288) and questionably present in an additional 15% (43/288) of subjects. PPPEDs were found most commonly in the temporal quadrant (39.2%). The prevalence of PPPEDs and drusen both increased with age while PPA and PPP remained unchanged. When comparing the PPPED positive group to the PPPED negative group, there was a statistically significant difference in ages (older in the PPPED group) but no significant differences in gender or race. The presence of PPP correlated with the presence of PPPED (r=0.144, p=0.012) but its positive predictive value was only 41% (NPV 75%). The occurrence of PPPED did not correlate with the presence of PPA or drusen.
Conclusions: :
In this study, 42% of asymptomatic participants had definite or questionable PPPEDs which could not be seen with fundus imaging. The occurrence of PPPEDs was associated with age and peripapillary pigmentation. It is not known if these lesions represent deposition of drusen-like material or aborted choroidal neovascularization adjacent to the natural break in Bruchs membrane at the optic disc.
Keywords: retinal pigment epithelium • imaging/image analysis: clinical • optic nerve