Assessing choroidal thickness in eyes with idiopathic serous epithelial detachments in UK Biobank

Abstract

Purpose : Idiopathic serous epithelial detachments (SPEDs) are part of the spectrum of central serous chorioretinopathy (CSCR). This study presents imaging characteristics of those with idiopathic SPED compared to those without in UK Biobank (UKBB), a prospective cohort study.

Methods : UKBB is a biomedical database with over 500,000 UK participants aged 40-69 years. Of these, colour and optical coherence tomography (OCT) gradable images were obtained using spectral domain OCT (Topcon- 1000, Topcon, Japan) in 68517 participants. The images were graded masked by trained and certified graders.
Idiopathic SPED cases were selected for detailed grading; number of SPEDs, height, base diameter and location of the largest SPED, sub-foveal choroidal thickness (SFCT), maximum choroidal thickness (MCT), and greatest (vertical) choroidal vessel diameter (CVD) on the foveal scan.
A control-group of an equal number of pathology free UKBB eyes were graded using the same method. T-tests were used for comparisons, using SPSS v26.

Results : Of the 68517 available retinal images, 109 eyes (85 patients) had at least one idiopathic SPED, 12 patients had bilateral SPEDs. 76% of eyes had one SPED, 17% had two SPEDs, 4% three, 2% four and 2% over 5. Mean SPED height was 100.2µm (range 23-501) and mean base diameter 483.97µm (119-1961).
Extra-foveal SPEDs were present in 73%, 19% were juxta-foveal and 8% sub-foveal (geometric centre of the fovea). There was a slight predilection for superior and nasal presentation but this was not significant.
There was a significant difference in mean SFCT between groups, 355µm (141-567) for those with SPED and 265 µm (111-443) for those without (p<0.001). With SPED the mean MCT was 414 µm (190-567), 320 µm (176-458) for those without (p<0.001). CVD was also significantly different; 191 µm (108-439) for SPED eyes and 165 µm (93-267) for non-SPEDs (p<0.001).

Conclusions : SFCT and MCT were significantly higher in those with SPEDs than those without. Additionally CVD of the largest gradable vessel (foveal scan) was significantly greater in those with SPEDs, signifying choroidal vascular changes in those with SPED. The weakness of the study was that no enhanced depth imaging was available for this cohort, however we demonstrated the feasibility of using this image set for SPED analysis.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.