Abstract
Purpose: :
To measure macular choroidal thickness (CT) in highly myopic eyes and to correlate with macular retinoschisis using enhanced depth imaging optical coherence tomography (EDI-OCT).
Methods: :
This is a retrospective, observational case series study. EDI-OCT images were obtained in highly myopic eyes (≥6 diopters. D), with and without retinoschisis, with a spectral domain OCT (3D-OCT 1000 Mark II; Topcon Corp., Tokyo, Japan). The subfoveal choroidal thickness was measured from the outer border of the retinal pigment epithelium to the inner scleral border. Statistical analysis was performed to evaluate CT and to correlate it with age, refractive error on eyes with and without macular retinoschisis.
Results: :
We studied 28 eyes of 16 patients aged between 36-71 years (mean 53.6 ± 11.5). There were 13 women and 3 men. The mean refractive error was -13.3±5.3 D. There were 10 eyes with macular retinoschisis (36%). The mean CT was 158.3±74.8µm (range: 33-286). It was correlated negatively with the refractive error (p=0.002), but not with the age (p=0.625), visual acuity (p=0.151) or presence or absence of retinoschisis. Regression analysis suggested that subfoveal CT decreased 7.49µm for each diopter of myopia.
Conclusions: :
Choroidal thickness is diminish in high myopic eyes and correlated indirectly to the degree of myopia. Nevertheless, macular schisis seems to be an independent finding in our serie. This result provides additional evidence that macular schisis is not related with choroidal changes and support the vitreous tractional theories.
Keywords: myopia • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • choroid