Abstract
Purpose: :
To investigate the photoreceptor layer in the idiopathic epiretinal membrane (ERM) using tissue layer image of spectral domain optical coherence tomography (SD-OCT).
Methods: :
The medical records of twenty eight eyes were reviewed to collect visual acuity (VA) and SD-OCT images before and after surgery. The integrity of the inner and outer segment (IS/OS) junction was evaluated in the cross-sectional images of SD-OCT. The scanned data were processed to generate tissue layer image of the photoreceptor layer (photoreceptor layer map, PLM). Relative reflectivity and hyporeflectivity index of 1 mm and 2 mm zones in the macular center were analyzed to evaluate correlations with VA.
Results: :
A normal IS/OS line was detected in 21.4% and 28.6% before and after surgery. Mean central subfield macular thickness (CSMT) was reduced from 466.1 µm to 387.4 µm after membrane peeling (p<0.001) . Mean relative reflectivities of 1 mm and 2 mm zone were altered from 0.66 and 0.70 to 0.66 and 0.71 postoperatively. Mean hyporeflectivity indexes of PLMs were changed from 1.78 and 8.03 to 1.72 and 7.16 after surgery. Postoperative VA had positive correlations with the hyporeflectivity indexes (correlation coefficient r =0.45-0.667; P <0.05), but not with the relative reflectivity.
Conclusions: :
In idiopathic ERM, PLMs using SD-OCT appear to be useful to investigate the integrity of the photoreceptor layer. Hyporeflectivity index of PLMs was supposed to be a predictor for visual outcomes.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • vitreoretinal surgery • retina