Abstract
Purpose: :
Studies have reported focal macular thinning in 50% of eyes of sickle cell hemoglobinopathy (SCH) patients. This study, utilizing enhanced depth imaging (EDI) OCT, sought to ascertain whether choroidal thickness in SCH eyes varied from control eyes and whether these changes correlated with macular thinning in these eyes.
Methods: :
In this prospective study, SCH patients and non-SCH, race-matched controls underwent EDI SD-OCT imaging using the Heidelberg Spectralis machine. The choroid was measured from the outer border of the RPE to the inner border of the sclera at 500 µm intervals spanning 3 mm nasal to 3 mm temporal to the foveal center. Mean sub-foveal choroidal thickness within a 500 µm radius of the fovea and choroidal thickness corresponding to regions of retinal thinning were also measured. The sickle eyes were subdivided into groups: 1) no retinal thinning or foveal splaying, 2) retinal thinning only, 3) foveal splaying only, and 4) retinal thinning with foveal splaying. T-tests, ANOVA tests, and Bonferoni post-hoc analysis were performed to analyze differences in choroidal thickness among these four groups and control eyes.
Results: :
EDI SD-OCT images from 25 eyes of 13 SCH patients and 17 eyes of 10 control patients were analyzed. Among the SCH group, 6 eyes of 3 patients were myopic, and the remaining 19 eyes were plano. Of the 25 eyes, 4 represented Group 1, 6 represented Group 2, 4 represented Group 3, and 11 represented Group 4. The choroid was significantly thinner (p<0.05) in sickle eyes in the sub-foveal region and the area ranging from 2.5 mm nasal to 0.5 mm temporal to the fovea when compared to controls. Furthermore, all 5 groups had significantly different (p<0.05) choroidal thickness in the mean sub-foveal region and the area spanning 2.5 mm nasal to the fovea. The choroidal thickness in this region was significantly different primarily between Group 2 and control eyes. Of the 17 eyes with macular thinning, 8 (47%) eyes demonstrated choroidal thinning in the area of macular thinning.
Conclusions: :
Choroidal thickness was significantly thinner in SCH eyes than in non-SCH control eyes in the subfoveal and nasal macular regions. Eyes with macular thinning demonstrated choroidal thinning in the nasal macula as compared to controls. Foveal splaying did not correlate with choroidal thinning. However, eyes with macular thinning may exhibit choroidal thinning in the same region.
Keywords: imaging/image analysis: clinical • choroid • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)