Abstract
Purpose:
To define anatomic normality curves of different retinal and choroidal variables in healthy subjects using SD-OCT
Methods:
Transversal and descriptive study realized at an ophthalmological reference hospital from August 2013 to December 2014. Healthy subjects were selected by consecutive recruitment analyzing one eye for retinal and choroidal variables, and both eyes to analyze symmetry of nerve fiber layer. Inclusion criteria was a spherical refractive error from +2.00 to -9.00, age between 18 and 69 years old, cup-to-disc ratio ≤0.5, and intraocular pressure less than 18 mmHg. Patients with media opacities, chronic systemic diseases and other ophthalmolical disease were excluded. Images were obtained according to a standarized protocol. Retinal and nerve fiber layer were automatically analyzed by custom software; choroidal variables were manually segmentated with previous validation of measurements.
Results:
A total of 70 patients were included 31 males, and 39 females with a mean age of 40 years. Results were reported for central and sectorial thickness. Main values of central thickness were as follows: Foveal central thickness 222.5 μm (SD 21.81μm); choroidal central thickness 302.1 μm (SD 52.72 μm); global retinal volumen 8.89 mm3 ; global choroidal volumen 4.99 mm3 (SD 0.82 μm) ; nerve fiber layer assymetry by quadrants: superior -6.96 μm , temporal -3.51 μm , nasal 15 μm and inferior 5.46 μm. Differences of thickness were not observed between age groups or between gender.
Conclusions:
It is important to determine normal values for choroidal and retinal thickness in healthy population to determine pathology. With more normality curves databases it would be easier to determine the normality and also make the Optical Coherence Tomography a gold standard method for its measurement.