Abstract
Purpose:
To compare the pathologic changes in eyes with cone rod dystrophy (CRD) and rod cone dystrophy using spectral domain optical coherence tomography (SDOCT).
Methods:
We investigated 35 eyes of 35 patients with CRD. As a control, we included visual acuity-matched patients with rod cone dystrophy. Visual acuity, mean deviation measured with Humphrey perimeter, amplitude of rod-, combine-, cone-, and flicker- ERG, and central retinal thickness was compared between the groups. The SDOCT findings including the presence or the absence of external limiting membrane (ELM), inner segment / outer segment junction (IS/OS), or cone outer segment tips (COST) was judged and compared.
Results:
Patients with CRD were younger than visual acuity-matched patients with rod cone dystrophy (51.7 ± 14.6 vs 60.2 ± 10.7 year old, P = 0.01) and showed preserved amplitude in ERG (P < 0.001 in all components). COST was less frequently observed in CRD compared to rod cone dystrophy (0 cases (0 %) vs 7 cases (20 %), P=0.011). In addition, SDOCT revealed subretinal hyporeflective space more frequently in CRD (9 cases (25.7 %) vs 2 cases (5.7%) P = 0.045).
Conclusions:
The difference of SDOCT findings between CRD and rod cone dystrophy was most prominent in the presence or absence of COST. In addition, subretinal hyporeflective space was more frequently observed in eyes with CRD. The findings should reflect the pathologic process of cone dominant degeneration in the disease.
Keywords: 696 retinal degenerations: hereditary •
550 imaging/image analysis: clinical