Abstract
Purpose: :
To investigate changes in the central and parafoveal retinal thickness in the early postoperative period after uneventful phacoemulsification cataract surgery using two spectral domain OCT devices.
Methods: :
29 eyes of 26 patients were included in this prospective study. Measurement of retinal thickness was done using two spectral domain OCT systems (Cirrus, Carl Zeiss Meditec; Spectralis; Heidelberg Engineering). Measurements were taken with a 512x128 raster in the Cirrus and a 37 frame volume scan in the Spectralis. Retinal maps were analysed in 9 subfields based on ETDRTS-ring for thickness analysis. Best corrected visual acuity (BCVA) was assessed at 6 meters using Snellen charts. Examinations were performed preoperatively, day 1, day 7 as well as 30 and 90 days after cataract surgery.
Results: :
Mean thickness of the central 1mm retinal field at baseline was 284µm, 270µm, 281µm, 296µm and 284µm using Cirrus and 311µm, 300µm, 293µm, 322µm and 317µm using Spectralis, at day 1, days 7, 30 and 90, respectively (p>0.05). No significant changes were found regarding thickness of the ETDRS-ring subfields after surgery compared to baseline (p>0.05). All over 3 patients showed a clinically non relevant increase of more than 50µm due to intraretinal cysts and cystoid macular edema with first appearance at day 30. Analyzing all ETDRS-ring subfields, mean retinal thickness with the Spectralis were 20µm higher than with the Cirrus. Mean thickness values were significantly higher in 58% of the ETDRS-ring subfields using Spectralis OCT compared to Cirrus (p range 0.001 to 0.04).
Conclusions: :
Using spectral domain OCT systems, no significant changes were found with regard to retinal thickness measurement in the central and parafoveal areas after uneventful cataract surgery. However, clinically non relevant cystic edema was found in 10% of the eyes appearing not later than day 30. Macular changes in retinal thickness and morphology are most likely to be found until the 30th post-operative day after cataract surgery.
Keywords: cataract • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)