Evaluating choroidal thickness in diabetic retinopathy

Abstract

Chee Yee Chan,1 Thanos D Papakostas,2 Demetrios Vavvas2 1Department of Ophthalmology, 2Retina Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USAWe read with interest the article by Unsal et al1 and congratulate them on their work assessing choroidal thickness in patients with diabetic retinopathy. We will like to highlight some factors of relevance.Unsal et al state that their measurement of the choroid was from the outer part of the retinal pigment epithelial layer to the choroidal scleral junction.1 However, their Figure 2 seems to draw the upper border of the choroid at various locations (external limiting membrane, inner/outer segment junction, top of the retinal pigment epithelium).1 An illustrative diagram (Figure 1) for measuring choroidal thickness can be seen in the study reported by Copete et al.2 Recent studies of the thickness of the retinal pigment epithelium–Bruch’s membrane complex in normal individuals ranged from 17.5 μm to 28.2 μm.3 Hence, measurement of choroidal thickness has to be drawn correctly and consistently at the same location (outer part of the retinal pigment epithelium) to minimize potential inaccuracies. View original paper by Unsal and colleagues.