Abstract
Purpose: :
Retinal vessels following surgical epiretinal membrane (ERM) removal shows a visible outward shift in their position on serial confocal scanning laser ophthalmoscopy (SLO) images. This study was aimed at determining the correlation of vessel shift on SLO with vision compared to changes on optical coherence tomography (OCT) foveal thickness.
Methods: :
Data from patients who underwent ERM removal, evaluated by SLO and spectral OCT as part of the assessment pre and post-surgery were retrospectively reviewed. Patients showing a clear shift in retinal vessel position on SLO scan overlay were selected for further analysis. Data analyzed consisted in visual acuity (VA), OCT foveal profile and thickness and degree of retinal vessel shift at the pre-operatory visit and at 3 months’ time. Statistical analysis was performed by the two tail-T test.
Results: :
Eight eyes (M/F=5/3, mean age 70 year-old) were included, all cases showing a clear shift in retinal vessel position on SLO images. All patients had improved their VA after surgery: mean preoperative VA was 0,57 (decimal scale) while it was 0,78 at 3 months post-surgery (p=0.03). OCT images showed an intact inner/outer segment line in all scans. Foveal depression was absent in the preoperative scan in 6 cases; 3 months after surgery it was still absent in 4 of them. Mean OCT foveal thickness before surgery was 382µm and 361µm at 3 months (p=0.62).
Conclusions: :
The appearance of an outward shift of vessels on serial SLO images pre-dates improvements in OCT appearance and appears to be correlated with an early improvement in VA. Changes in retinal surface anatomy may be a better predictor of visual improvement than OCT structural changes.
Keywords: retina • imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)