Evaluating choroidal pigmentation in the setting of polypoidal choroidal vasculopathy in a Caucasian population

Abstract

Purpose : To evaluate the inter- and intra-observer reproducibility of a clinical choroidal pigmentation grading scale for the assessment of choroidal pigmentation in Caucasian patients with polypoidal choroidal vasculopathy (PCV).

Methods : To establish the scale reproducibility, a single master grader assessed 15 patients (5 in each group) to have a either a “light”, “medium” or “dark” choroid (Figure 1). Two cropped images from the inferior and superior mid-peripheral retina of each eye were graded twice, 3 weeks apart, by 3 independent, blinded graders. Similarly, the choroidal pigmentation of a separate cohort of 16 Caucasian patients (31 eyes) with PCV was compared with a control group of 16 Caucasian patients (32 eyes). The controls were identified by reviewing 145 consecutive patients seen by LY at VRM. Exclusion criteria included age < 50, non-Caucasian by self-identification, known choroidal pathology or subfoveal choroidal thickness < 200 or > 350 microns. Because significant media opacity and variation in choroidal thickness can affect the contrast of the choroidal vasculature against the surrounding choroid, patients with either were excluded.

Results : The clinical grading of choroidal pigmentation was shown to be reproducible, with an average intra-observer agreement of 93.33% (SD 1.67). We demonstrated high inter-observer agreement as well, with Kappa values of 0.9333 and 0.8997 on the 1^st and 2^nd randomization, respectively. The mean choroidal thickness for eyes with PCV compared to the control eyes was comparable (232 versus 263 microns). The PCV cohort was 56% female versus 50% in the controls and was older than the patients with no disease (mean age: 78.9 years versus 70.4 years). Preliminary grading results showed that PCV patients had darker choroidal pigmentation versus patients with no choroidal disease (71% of PCV patients had a “dark” choroid, compared with 47% of the controls, p = 0.0103).

Conclusions : This study demonstrates that our method of clinical grading of choroidal pigmentation has good inter- and intra-observer reproducibility. Preliminary results suggest that Caucasian patients with PCV may have darker choroidal pigmentation compared to patients with no choroidal disease.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Figure 1: An example of light (A), medium (B) and dark (C) choroidal pigmentation, defined by comparing the color of the choroidal vasculature to the surrounding choroidal pigmentation