Glaucoma and Choroidal Thickness

Since the landmark study by Spaide and colleagues on the development of enhanced depth imaging by optical coherence tomography, an increasing number of studies have addressed choroidal thickness in normal eyes, factors associated with choroidal thickness in normal eyes, and associations of choroidal thickness with various retinal and retinochoroidal disorders. These studies have revealed that mean subfoveal choroidal thickness (SFCT) in normal eyes is approximately 250μm in a population with mean age of 65 years, 5 that it shows huge variability ranging from values as thin as 8μm to as large as 854μm, that it decreases with age by 4μm per year of older age and by 15 μm per diopter of increasing myopia, and that it is associated with male gender, a deeper anterior chamber and a thicker lens. 5 Clinical studies also showed that patients with central serous chorioretinopathy have a thickened SFCT in the affected eye as well as in the contralateral unaffected eye, and that patients with polypoidal vascular choroidopathy have increased SFCT in association with dilatation of large choroidal vessels. A recent study suggested that choroidal thickness is additionally influenced by brain pressure. 6 With respect to choroidal thickness in angle-closure glaucoma, Arora and colleagues recently reported that choroidal thickness was significantly greater in the angle closure glaucoma group than in the open angle glaucoma group and normal subjects, with no significant difference between eyes with open angle glaucoma and normal subjects. 7 Also after adjusting for age, axial length, intraocular pressure and central corneal thickness, choroidal thickness was significantly greater in the angle closure glaucoma group than either normal eyes or those with open angle glaucoma. Interestingly, the severity of glaucomatous optic nerve damage as measured by cup/disc ratio or visual field mean deviation was not significantly associated with choroidal thickness. In another investigation, Arora and coworkers reported a significant increase in choroidal thickness and a decrease in anterior chamber depth when water drinking test was performed in eyes with anterior chamber angle closure as compared to eyes with open anterior chamber angles. 8 In another recent study on fellow eyes of 44 patients with unilateral acute primary angle closure, Zhou and colleagues observed that the unaffected fellow eyes had thicker choroid than a group of control eyes after adjusting for age, axial length and gender. 9 In this issue of JOVR, Hosseini and colleagues presented a study on macular and peripapillary choroidal thickness …