Abstract
Purpose :
The choroid is involved in retinal pathologies that are sight threatening. It was the purpose to study the choroidal thickness and their correlations in patients of myopia in Central India, where previous data are not available.
Methods :
100 (199 eyes) myopic subjects (53 females)were included. The mean age was 26.65 ±10.51 yrs. Ocular biometry, fundus photography and spectral domain oct, including enhanced depth imaging of the optic disc and for the choroid was performed. Morphometric parameters of the optic disc, parapapillary atrophy (PPA) and the sub-foveal choroid thickness (SFCT) were measured.
Results :
The mean values were for BCVA in DU 0.77±0.27, spherical equivalent -5.90±3.81 axial length 25.50±1.78 mm.(22.00 - 35.57), and IOP 15.08±2.68 mm.Hg. Mean disc diameter vertical was 1.98±0.77 mm. Mean number of clock hours of PPA ( 103 eyes) was 6.77±3.63 The maximum width of PPA was 556.91±430 μm (50-2227). Mean SFCT was 262.71±105 μm (17-584). For mild myopia (n=38) ( < 3 D) it was 331.60±105 μm (103-539) for moderate myopia (n=94) (3-6D) it was 274.15±98.16 μm (25 - 584) and for high myopia (n=67) ( >6D) it was 204.50+82.86μm (17-368).
Bivariate correlations of the SFCT showed significant correlation with age (P=0.001;r=-0.239), male gender (P=0.005;r=0.198), increasing spherical equivalent (P<0.001;r=0.539), BCVA (P<0.001;r=0.478) and vertical disc diameter (P=0.035;r=0.150). SFCT decreased significantly with age ((P=0.001;r=-0.239) and increasing axial length (P<0.001;r=-0.581). There was a negative correlation with extent of PPA in clock hours (P<0.001;r=-0.504) and with the maximum width of PPA (P<0.001;r=-0.487). Multivariate analysis with subfoveal choroidal thickness as dependant variable and age, BCVA, axial length, disc diameter vertical, and extent of PPA as independant variables, showed a significant correlation with BCVA (P=0.008), axial length (P=0.004), and extent of PPA (P=0.014).
Conclusions :
The values of subfoveal choroidal thickness were determined using Enhanced Depth Imaging with SD -OCT. Increased axial length and greater circular extent of PPA was associated with a thinner choroid. Better BCVA was correlated with a thicker choroid. The study determines the ocular parameters that are associated with choroidal thickness and may play a role in the health of a myopic eye.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.