A Pilot Study of Fourier-Domain Optical Coherence Tomography of Retinal Dystrophy Patients

Purpose

To characterize the macular anatomy of retinal dystrophy eyes using high-speed, high-resolution, Fourier-domain optical coherence tomography (FD-OCT).

Design

Case-control study.

Methods

Retinal dystrophy patients and normal age- and gender-matched controls underwent FD-OCT imaging using the RTVue (Optovue Inc, Fremont, California, USA). Vertical and horizontal 8-mm scans of 1024 lines/cross-section were obtained. Based on boundaries manually drawn on computer displays of OCT cross-sections, the thicknesses of the retina, inner retinal layer (IRL), and outer retinal layer (ORL) were averaged over both 5-mm (macular) and 1.5-mm (foveal) regions centered at the fovea. The IRL was the sum of nerve fiber layer (NFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) thicknesses. Total retinal thickness (RT) was measured between the internal limiting membrane (ILM) and the retinal pigment epithelium. ORL thickness was calculated by subtracting IRL thickness from RT.

Results

Fourteen patients (three retinitis pigmentosa, two cone-rod degeneration, two Stargardt disease, and seven normal controls) underwent FD-OCT imaging. Mean foveal RT was 271.3 ± 23.3 μm for controls and 158.4 ± 47.1 μm for retinal dystrophy patients (P < .001). Mean macular RT was 292.8 ± 8.1 μm for controls and 199.1 ± 32.6 μm for retinal dystrophy patients (P < .001). Mean macular ORL was 182.9 ± 4.7 μm for controls and 101.3 ± 18.7 μm for retinal dystrophy patients (P < .001); mean macular IRL was 109.9 ± 6.4 μm for controls and 97.9 ± 20.7 μm for retinal dystrophy patients (P = .06).

Conclusion

Eyes with retinal dystrophy had a small (11%) decrease in macular IRL and severe (45%) decrease in macular ORL compared to normal controls.