Abstract
Purpose: :
To investigate the relationship between macular morphology and macular function in patients with advanced retinitis pigmentosa (RP) using optical coherence tomography (OCT) and multifocal electroretinography (mfERG).
Methods: :
Twenty-eight eyes of 16 patients with RP who had non-recordable full-field electroretinography (ffERG) were enrolled in the study. All subjects underwent ophthalmic examination including visual acuity (VA), mfERG(VERIS; Electro-Diagnostic Imaging, Inc., Redwood City, CA) and Cirrus spectral domain OCT (Carl Zeiss Meditec, Dublin, CA).The patients were morphologically divided into three groups by the OCT findings; group A: retinal thinning (due to cell loss), group B: normal macular contour, group C: retinal thickening (due to cystoids macular edema). Functional results for VA and mfERG were compared and analyzed based on the three groups.
Results: :
The mean foveal thickness on OCT of group A, B and C were 156.4, 207.4 and 344.3µm, respectively. The average VA was significant decreased in group A than in group C (p=0.035). There were no significant VA differences between group B and C (p=0.356). In the mfERGs, there were no detectable responses in peripheral retina. The average implicit time of central retina was more delayed in group A compared to group C (p<0.05). Significant differences of the amplitude were not observed among three groups.
Conclusions: :
Despite of the cystoids change, the VA of group C was relatively well preserved. These results could suggest that the patients with retinal cystoid change tend to have intact macular function compared to the patient with retinal thinning in RP. The implicit time showed the statistically difference, whereas amplitude did not. The exact reasons of this discrepancy need further evaluation.
Keywords: electroretinography: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal degenerations: hereditary