Session Title: Imaging II
Session Date/Time: Friday 18/09/2015 | 16:30-18:00
Paper Time: 16:38
First Author: : Z.Eldaly EGYPT
Co Author(s): : S. Kedwany N. Magdy
PURPOSE:To measure the choroidal thickness and its location-based profile in young healthy Egyptian subjects and the correlation with age and blood pressure.
A prospective observational study was conducted in Tiba Eye Center (private practice), Assiut, Egypt from January 2014 till September 2014.
A prospective observational study recruited 35 young volunteers with no ophthalmic or systemic disease. They were evaluated by Enhanced Depth Imaging (EDI) technology of Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany). Eyes with high myopia (exceeding -6 D), retinal/choroidal disease, and previous ocular trauma were excluded. Two line scans (vertical and horizontal), centered on the fovea, were taken with 100-averaged frames. Choroidal thickness was defined as the vertical distance from the high reflective line of Bruch’s membrane to the high reflective line of the inner surface of the sclera. Choroidal thickness were measured in 9 different locations, central sub-foveal thickness, 1 mm and 2 mm superior, inferior, temporal and nasal to foveal center. The measurements were performed using the Heidelberg Eye Explorer software (Heidelberg Engineering, Heidelberg, Germany). Blood pressure and choroidal thickness were measured at the same setting and day time (afternoon) for all patients by a single experienced physician (Z. E.) to avoid possible diurnal variation in choroidal and retinal thickness.
Sixty three eyes were evaluated. Mean age of the volunteers was 25.3 ± 5.2 years (20-37 years). Mean central sub-foveal choroidal thickness was 297.1 ± 92.2 um. Mean choroidal thickness 1 mm temporal, nasal, superior and inferior to foveal center were 293.2 ± 55.2 um, 296 ±73.3 um, 326.2 ± 63.7 um and 306.8 ± 62.2 um respectively. Mean choroidal thickness 2 mm temporal, nasal, superior and inferior to foveal center were 262.4 ± 104.9, 251.3 ± 90.3 um, 331.5 ± 53.6 um and 307.7 ± 56.9 um respectively. Mean central foveal thickness was 229.9 ± 7.1 um.There are variable positive but non-significant correlation between mean BP and mean choroidal thickness in temporal, nasal, superior and inferior sectors (r = 0.169, 0.025, 0.38 and 0.41 respectively). There are variable negative but non-significant correlation between age and mean choroidal thickness in temporal, nasal, superior and inferior sectors (r = 0.169, 0.025, 0.38 and 0.41 respectively) and positive non-significant correlation between age and mean choroidal thickness in superior sectors.
EDI-OCT is an important tool in the evaluation of choroidal thickness. Choroidal thickness profile depends upon its location. Correlation between blood pressure and choroidal thickness could be a key to many unanswered questions in retinal vascular diseases. To our knowledge, this is the first normative database for choroidal thickness among Egyptian population.