Changes in choroidal thickness and choroidal vascularity index in thyroid eye disease: a systematic review

There currently does not exist guidance for authors aiming to undertake systematic reviews of observational epidemiological studies, such as those reporting prevalence and incidence information. These reviews are particularly useful to measure global disease burden and changes in disease over time. The aim of this article is to provide guidance for conducting these types of reviews.

The vascularity of the choroid has been implicated in the pathogenesis of various eye diseases. To date, no established quantifiable parameters to estimate vascular status of the choroid exists. Choroidal vascularity index (CVI) may potentially be used to assess vascular status of the choroid. We aimed to establish normative database for CVI and identify factors associated with CVI in healthy eyes. In this population-based study on 345 healthy eyes, choroidal enhanced depth imaging optical coherence tomography scans were segmented by modified image binarization technique. Total subfoveal choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area. CVI was calculated as the proportion of LA to TCA. Linear regression was used to identify ocular and systemic factors associated with CVI and subfoveal choroidal thickness (SFCT). Subfoveal CVI ranged from 60.07 to 71.27% with a mean value of 65.61 ± 2.33%. CVI was less variable than SFCT (coefficient of variation for CVI was 3.55 vs 40.30 for SFCT). Higher CVI was associated with thicker SFCT, but not associated with most physiological variables. CVI was elucidated as a significant determinant of SFCT. While SFCT was affected by many factors, CVI remained unaffected suggesting CVI to be a more robust marker of choroidal diseases.

Approximately 35% of patients with Graves' ophthalmopathy do not respond to immunosuppressive treatment. A possible explanation for this finding is that only patients with active ophthalmopathy respond to immunosuppressive treatment, whereas patients with fibrotic end stage disease do not. To distinguish between these two groups and to predict the outcome of immunosuppressive treatment, we developed a clinical activity score (CAS) based on four of the five classical signs of inflammation and tested its efficacy in a double-blind, prospective study. The CAS was determined by an opthalmologist before, on the day of, and after the start of either oral prednisone or retrobulbar irradiation in 43 patients with moderate to severe Graves' ophthalmopathy. The therapeutic outcome was determined by a second ophthalmologist unaware of the CAS stores given. Success of treatment was defined as an improvement in NOSPECS class or grade. Responders (22) and non-responders (21) did not differ in age, sex, duration or severity of their Graves' ophthalmopathy. The pretreatment CAS, however, was significantly higher in responders than in non-responders. Twelve of 22 responders and three of 21 non-responders had a CAS > or = 4 (55% vs 14%; P or = 4 had a similar duration of Graves' ophthalmopathy as patients with a CAS < 4. The clinical activity score has a high predictive value for the outcome of immunosuppressive treatment in Graves' ophthalmopathy. Disease activity, and not disease duration, is the prime determinant of therapeutic outcome.