Abstract
Purpose: :
To evaluate the ability of confocal scanning laser ophthalmoscope (SLO) retromode imaging technique to detect retinal changes caused by choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and to compare these findings with those obtained by optical coherence tomography (OCT), considered as reference examination.
Methods: :
Seventeen eyes of 13 consecutive patients affected by CNV secondary to AMD were evaluated with time domain OCT to detect neuroretinal detachment (NRD), pigment epithelial detachment (PED), cystoid macular edema (CME) and epiretinal membranes (ERM). All eyes were also examined with a SLO which acquires retromode images (RM) using an infrared laser (F 10, Nidek, Japan). The RM image is a pseudo-three-dimensional image which allows to detect both presence and extention of retinal lesions. Infrared (IR) and fundus autofluorescence (FAF) images were also obtained, with the same SLO system. All images were analyzed by two independent masked examiners.
Results: :
NRD was detected by OCT in 8 eyes; RM showed higher sensitivity (sensitivity = 62.5%, specificity = 66.7%, P0=64.7%) compared to other imaging techniques (IR: sensitivity = 25%, specificity = 88.9%, P0 = 58.8%; FAF: sensitivity = 12.5%, specificity = 88.9%, P0 = 52.9%). Four eyes had PED at OCT; only RM correctly identified these lesions (sensitivity=100%, specificity= 69.2%, P0 = 76.5%). CME was detected by OCT in 8 eyes; very good agreement was found only between OCT and RM (sensitivity=87.5%, specificity= 88.9%, P0 = 88.2%), whereas FAF showed low sensitivity and high specificity (25% and 100% respectively, P0 =64.7%). ERMs were present in 3 eyes at OCT; good agreement was found between OCT, and both IR and RM (P0 = 88.2% and 94.1% respectively). Sensitivity was 66.7% for both imaging techniques, while specificity was 92.9% for IR and 100% for RM. Inter-observer OCT agreement was excellent for all features (P0 =100%). Inter-observer SLO agreement was very good for CME at FAF (P0 =94.1%) and at RM (P0 =94.1%).
Conclusions: :
Retromode SLO imaging is a useful and reproducible technique in detecting retinal features associated with CNV, mainly CME, compared to OCT. However, cross OCT sections do not allow to depict three-dimensionally the extent of retinal changes due to CNV, which are better visualized with an en-face retromode imaging technique.
Keywords: choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical